1 This is doc/gccint.info, produced by makeinfo version 4.8 from 2 /Volumes/project-jingyu/android_toolchain/build/../gcc/gcc-4.4.0/gcc/doc/gccint.texi. 3 4 Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 5 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free 6 Software Foundation, Inc. 7 8 Permission is granted to copy, distribute and/or modify this document 9 under the terms of the GNU Free Documentation License, Version 1.2 or 10 any later version published by the Free Software Foundation; with the 11 Invariant Sections being "Funding Free Software", the Front-Cover Texts 12 being (a) (see below), and with the Back-Cover Texts being (b) (see 13 below). A copy of the license is included in the section entitled "GNU 14 Free Documentation License". 15 16 (a) The FSF's Front-Cover Text is: 17 18 A GNU Manual 19 20 (b) The FSF's Back-Cover Text is: 21 22 You have freedom to copy and modify this GNU Manual, like GNU 23 software. Copies published by the Free Software Foundation raise 24 funds for GNU development. 25 26 INFO-DIR-SECTION Software development 27 START-INFO-DIR-ENTRY 28 * gccint: (gccint). Internals of the GNU Compiler Collection. 29 END-INFO-DIR-ENTRY 30 This file documents the internals of the GNU compilers. 31 32 Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 33 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free 34 Software Foundation, Inc. 35 36 Permission is granted to copy, distribute and/or modify this document 37 under the terms of the GNU Free Documentation License, Version 1.2 or 38 any later version published by the Free Software Foundation; with the 39 Invariant Sections being "Funding Free Software", the Front-Cover Texts 40 being (a) (see below), and with the Back-Cover Texts being (b) (see 41 below). A copy of the license is included in the section entitled "GNU 42 Free Documentation License". 43 44 (a) The FSF's Front-Cover Text is: 45 46 A GNU Manual 47 48 (b) The FSF's Back-Cover Text is: 49 50 You have freedom to copy and modify this GNU Manual, like GNU 51 software. Copies published by the Free Software Foundation raise 52 funds for GNU development. 53 54 55 56 File: gccint.info, Node: Top, Next: Contributing, Up: (DIR) 57 58 Introduction 59 ************ 60 61 This manual documents the internals of the GNU compilers, including how 62 to port them to new targets and some information about how to write 63 front ends for new languages. It corresponds to the compilers 64 (GCC) version 4.4.0. The use of the GNU compilers is documented in a 65 separate manual. *Note Introduction: (gcc)Top. 66 67 This manual is mainly a reference manual rather than a tutorial. It 68 discusses how to contribute to GCC (*note Contributing::), the 69 characteristics of the machines supported by GCC as hosts and targets 70 (*note Portability::), how GCC relates to the ABIs on such systems 71 (*note Interface::), and the characteristics of the languages for which 72 GCC front ends are written (*note Languages::). It then describes the 73 GCC source tree structure and build system, some of the interfaces to 74 GCC front ends, and how support for a target system is implemented in 75 GCC. 76 77 Additional tutorial information is linked to from 78 `http://gcc.gnu.org/readings.html'. 79 80 * Menu: 81 82 * Contributing:: How to contribute to testing and developing GCC. 83 * Portability:: Goals of GCC's portability features. 84 * Interface:: Function-call interface of GCC output. 85 * Libgcc:: Low-level runtime library used by GCC. 86 * Languages:: Languages for which GCC front ends are written. 87 * Source Tree:: GCC source tree structure and build system. 88 * Options:: Option specification files. 89 * Passes:: Order of passes, what they do, and what each file is for. 90 * Trees:: The source representation used by the C and C++ front ends. 91 * RTL:: The intermediate representation that most passes work on. 92 * GENERIC:: Language-independent representation generated by Front Ends 93 * GIMPLE:: Tuple representation used by Tree SSA optimizers 94 * Tree SSA:: Analysis and optimization of GIMPLE 95 * Control Flow:: Maintaining and manipulating the control flow graph. 96 * Loop Analysis and Representation:: Analysis and representation of loops 97 * Machine Desc:: How to write machine description instruction patterns. 98 * Target Macros:: How to write the machine description C macros and functions. 99 * Host Config:: Writing the `xm-MACHINE.h' file. 100 * Fragments:: Writing the `t-TARGET' and `x-HOST' files. 101 * Collect2:: How `collect2' works; how it finds `ld'. 102 * Header Dirs:: Understanding the standard header file directories. 103 * Type Information:: GCC's memory management; generating type information. 104 * Plugins:: Extending the compiler with plugins. 105 106 * Funding:: How to help assure funding for free software. 107 * GNU Project:: The GNU Project and GNU/Linux. 108 109 * Copying:: GNU General Public License says 110 how you can copy and share GCC. 111 * GNU Free Documentation License:: How you can copy and share this manual. 112 * Contributors:: People who have contributed to GCC. 113 114 * Option Index:: Index to command line options. 115 * Concept Index:: Index of concepts and symbol names. 116 117 118 File: gccint.info, Node: Contributing, Next: Portability, Prev: Top, Up: Top 119 120 1 Contributing to GCC Development 121 ********************************* 122 123 If you would like to help pretest GCC releases to assure they work well, 124 current development sources are available by SVN (see 125 `http://gcc.gnu.org/svn.html'). Source and binary snapshots are also 126 available for FTP; see `http://gcc.gnu.org/snapshots.html'. 127 128 If you would like to work on improvements to GCC, please read the 129 advice at these URLs: 130 131 `http://gcc.gnu.org/contribute.html' 132 `http://gcc.gnu.org/contributewhy.html' 133 134 for information on how to make useful contributions and avoid 135 duplication of effort. Suggested projects are listed at 136 `http://gcc.gnu.org/projects/'. 137 138 139 File: gccint.info, Node: Portability, Next: Interface, Prev: Contributing, Up: Top 140 141 2 GCC and Portability 142 ********************* 143 144 GCC itself aims to be portable to any machine where `int' is at least a 145 32-bit type. It aims to target machines with a flat (non-segmented) 146 byte addressed data address space (the code address space can be 147 separate). Target ABIs may have 8, 16, 32 or 64-bit `int' type. `char' 148 can be wider than 8 bits. 149 150 GCC gets most of the information about the target machine from a 151 machine description which gives an algebraic formula for each of the 152 machine's instructions. This is a very clean way to describe the 153 target. But when the compiler needs information that is difficult to 154 express in this fashion, ad-hoc parameters have been defined for 155 machine descriptions. The purpose of portability is to reduce the 156 total work needed on the compiler; it was not of interest for its own 157 sake. 158 159 GCC does not contain machine dependent code, but it does contain code 160 that depends on machine parameters such as endianness (whether the most 161 significant byte has the highest or lowest address of the bytes in a 162 word) and the availability of autoincrement addressing. In the 163 RTL-generation pass, it is often necessary to have multiple strategies 164 for generating code for a particular kind of syntax tree, strategies 165 that are usable for different combinations of parameters. Often, not 166 all possible cases have been addressed, but only the common ones or 167 only the ones that have been encountered. As a result, a new target 168 may require additional strategies. You will know if this happens 169 because the compiler will call `abort'. Fortunately, the new 170 strategies can be added in a machine-independent fashion, and will 171 affect only the target machines that need them. 172 173 174 File: gccint.info, Node: Interface, Next: Libgcc, Prev: Portability, Up: Top 175 176 3 Interfacing to GCC Output 177 *************************** 178 179 GCC is normally configured to use the same function calling convention 180 normally in use on the target system. This is done with the 181 machine-description macros described (*note Target Macros::). 182 183 However, returning of structure and union values is done differently on 184 some target machines. As a result, functions compiled with PCC 185 returning such types cannot be called from code compiled with GCC, and 186 vice versa. This does not cause trouble often because few Unix library 187 routines return structures or unions. 188 189 GCC code returns structures and unions that are 1, 2, 4 or 8 bytes 190 long in the same registers used for `int' or `double' return values. 191 (GCC typically allocates variables of such types in registers also.) 192 Structures and unions of other sizes are returned by storing them into 193 an address passed by the caller (usually in a register). The target 194 hook `TARGET_STRUCT_VALUE_RTX' tells GCC where to pass this address. 195 196 By contrast, PCC on most target machines returns structures and unions 197 of any size by copying the data into an area of static storage, and then 198 returning the address of that storage as if it were a pointer value. 199 The caller must copy the data from that memory area to the place where 200 the value is wanted. This is slower than the method used by GCC, and 201 fails to be reentrant. 202 203 On some target machines, such as RISC machines and the 80386, the 204 standard system convention is to pass to the subroutine the address of 205 where to return the value. On these machines, GCC has been configured 206 to be compatible with the standard compiler, when this method is used. 207 It may not be compatible for structures of 1, 2, 4 or 8 bytes. 208 209 GCC uses the system's standard convention for passing arguments. On 210 some machines, the first few arguments are passed in registers; in 211 others, all are passed on the stack. It would be possible to use 212 registers for argument passing on any machine, and this would probably 213 result in a significant speedup. But the result would be complete 214 incompatibility with code that follows the standard convention. So this 215 change is practical only if you are switching to GCC as the sole C 216 compiler for the system. We may implement register argument passing on 217 certain machines once we have a complete GNU system so that we can 218 compile the libraries with GCC. 219 220 On some machines (particularly the SPARC), certain types of arguments 221 are passed "by invisible reference". This means that the value is 222 stored in memory, and the address of the memory location is passed to 223 the subroutine. 224 225 If you use `longjmp', beware of automatic variables. ISO C says that 226 automatic variables that are not declared `volatile' have undefined 227 values after a `longjmp'. And this is all GCC promises to do, because 228 it is very difficult to restore register variables correctly, and one 229 of GCC's features is that it can put variables in registers without 230 your asking it to. 231 232 233 File: gccint.info, Node: Libgcc, Next: Languages, Prev: Interface, Up: Top 234 235 4 The GCC low-level runtime library 236 *********************************** 237 238 GCC provides a low-level runtime library, `libgcc.a' or `libgcc_s.so.1' 239 on some platforms. GCC generates calls to routines in this library 240 automatically, whenever it needs to perform some operation that is too 241 complicated to emit inline code for. 242 243 Most of the routines in `libgcc' handle arithmetic operations that the 244 target processor cannot perform directly. This includes integer 245 multiply and divide on some machines, and all floating-point and 246 fixed-point operations on other machines. `libgcc' also includes 247 routines for exception handling, and a handful of miscellaneous 248 operations. 249 250 Some of these routines can be defined in mostly machine-independent C. 251 Others must be hand-written in assembly language for each processor 252 that needs them. 253 254 GCC will also generate calls to C library routines, such as `memcpy' 255 and `memset', in some cases. The set of routines that GCC may possibly 256 use is documented in *Note Other Builtins: (gcc)Other Builtins. 257 258 These routines take arguments and return values of a specific machine 259 mode, not a specific C type. *Note Machine Modes::, for an explanation 260 of this concept. For illustrative purposes, in this chapter the 261 floating point type `float' is assumed to correspond to `SFmode'; 262 `double' to `DFmode'; and `long double' to both `TFmode' and `XFmode'. 263 Similarly, the integer types `int' and `unsigned int' correspond to 264 `SImode'; `long' and `unsigned long' to `DImode'; and `long long' and 265 `unsigned long long' to `TImode'. 266 267 * Menu: 268 269 * Integer library routines:: 270 * Soft float library routines:: 271 * Decimal float library routines:: 272 * Fixed-point fractional library routines:: 273 * Exception handling routines:: 274 * Miscellaneous routines:: 275 276 277 File: gccint.info, Node: Integer library routines, Next: Soft float library routines, Up: Libgcc 278 279 4.1 Routines for integer arithmetic 280 =================================== 281 282 The integer arithmetic routines are used on platforms that don't provide 283 hardware support for arithmetic operations on some modes. 284 285 4.1.1 Arithmetic functions 286 -------------------------- 287 288 -- Runtime Function: int __ashlsi3 (int A, int B) 289 -- Runtime Function: long __ashldi3 (long A, int B) 290 -- Runtime Function: long long __ashlti3 (long long A, int B) 291 These functions return the result of shifting A left by B bits. 292 293 -- Runtime Function: int __ashrsi3 (int A, int B) 294 -- Runtime Function: long __ashrdi3 (long A, int B) 295 -- Runtime Function: long long __ashrti3 (long long A, int B) 296 These functions return the result of arithmetically shifting A 297 right by B bits. 298 299 -- Runtime Function: int __divsi3 (int A, int B) 300 -- Runtime Function: long __divdi3 (long A, long B) 301 -- Runtime Function: long long __divti3 (long long A, long long B) 302 These functions return the quotient of the signed division of A and 303 B. 304 305 -- Runtime Function: int __lshrsi3 (int A, int B) 306 -- Runtime Function: long __lshrdi3 (long A, int B) 307 -- Runtime Function: long long __lshrti3 (long long A, int B) 308 These functions return the result of logically shifting A right by 309 B bits. 310 311 -- Runtime Function: int __modsi3 (int A, int B) 312 -- Runtime Function: long __moddi3 (long A, long B) 313 -- Runtime Function: long long __modti3 (long long A, long long B) 314 These functions return the remainder of the signed division of A 315 and B. 316 317 -- Runtime Function: int __mulsi3 (int A, int B) 318 -- Runtime Function: long __muldi3 (long A, long B) 319 -- Runtime Function: long long __multi3 (long long A, long long B) 320 These functions return the product of A and B. 321 322 -- Runtime Function: long __negdi2 (long A) 323 -- Runtime Function: long long __negti2 (long long A) 324 These functions return the negation of A. 325 326 -- Runtime Function: unsigned int __udivsi3 (unsigned int A, unsigned 327 int B) 328 -- Runtime Function: unsigned long __udivdi3 (unsigned long A, 329 unsigned long B) 330 -- Runtime Function: unsigned long long __udivti3 (unsigned long long 331 A, unsigned long long B) 332 These functions return the quotient of the unsigned division of A 333 and B. 334 335 -- Runtime Function: unsigned long __udivmoddi3 (unsigned long A, 336 unsigned long B, unsigned long *C) 337 -- Runtime Function: unsigned long long __udivti3 (unsigned long long 338 A, unsigned long long B, unsigned long long *C) 339 These functions calculate both the quotient and remainder of the 340 unsigned division of A and B. The return value is the quotient, 341 and the remainder is placed in variable pointed to by C. 342 343 -- Runtime Function: unsigned int __umodsi3 (unsigned int A, unsigned 344 int B) 345 -- Runtime Function: unsigned long __umoddi3 (unsigned long A, 346 unsigned long B) 347 -- Runtime Function: unsigned long long __umodti3 (unsigned long long 348 A, unsigned long long B) 349 These functions return the remainder of the unsigned division of A 350 and B. 351 352 4.1.2 Comparison functions 353 -------------------------- 354 355 The following functions implement integral comparisons. These functions 356 implement a low-level compare, upon which the higher level comparison 357 operators (such as less than and greater than or equal to) can be 358 constructed. The returned values lie in the range zero to two, to allow 359 the high-level operators to be implemented by testing the returned 360 result using either signed or unsigned comparison. 361 362 -- Runtime Function: int __cmpdi2 (long A, long B) 363 -- Runtime Function: int __cmpti2 (long long A, long long B) 364 These functions perform a signed comparison of A and B. If A is 365 less than B, they return 0; if A is greater than B, they return 2; 366 and if A and B are equal they return 1. 367 368 -- Runtime Function: int __ucmpdi2 (unsigned long A, unsigned long B) 369 -- Runtime Function: int __ucmpti2 (unsigned long long A, unsigned 370 long long B) 371 These functions perform an unsigned comparison of A and B. If A 372 is less than B, they return 0; if A is greater than B, they return 373 2; and if A and B are equal they return 1. 374 375 4.1.3 Trapping arithmetic functions 376 ----------------------------------- 377 378 The following functions implement trapping arithmetic. These functions 379 call the libc function `abort' upon signed arithmetic overflow. 380 381 -- Runtime Function: int __absvsi2 (int A) 382 -- Runtime Function: long __absvdi2 (long A) 383 These functions return the absolute value of A. 384 385 -- Runtime Function: int __addvsi3 (int A, int B) 386 -- Runtime Function: long __addvdi3 (long A, long B) 387 These functions return the sum of A and B; that is `A + B'. 388 389 -- Runtime Function: int __mulvsi3 (int A, int B) 390 -- Runtime Function: long __mulvdi3 (long A, long B) 391 The functions return the product of A and B; that is `A * B'. 392 393 -- Runtime Function: int __negvsi2 (int A) 394 -- Runtime Function: long __negvdi2 (long A) 395 These functions return the negation of A; that is `-A'. 396 397 -- Runtime Function: int __subvsi3 (int A, int B) 398 -- Runtime Function: long __subvdi3 (long A, long B) 399 These functions return the difference between B and A; that is `A 400 - B'. 401 402 4.1.4 Bit operations 403 -------------------- 404 405 -- Runtime Function: int __clzsi2 (int A) 406 -- Runtime Function: int __clzdi2 (long A) 407 -- Runtime Function: int __clzti2 (long long A) 408 These functions return the number of leading 0-bits in A, starting 409 at the most significant bit position. If A is zero, the result is 410 undefined. 411 412 -- Runtime Function: int __ctzsi2 (int A) 413 -- Runtime Function: int __ctzdi2 (long A) 414 -- Runtime Function: int __ctzti2 (long long A) 415 These functions return the number of trailing 0-bits in A, starting 416 at the least significant bit position. If A is zero, the result is 417 undefined. 418 419 -- Runtime Function: int __ffsdi2 (long A) 420 -- Runtime Function: int __ffsti2 (long long A) 421 These functions return the index of the least significant 1-bit in 422 A, or the value zero if A is zero. The least significant bit is 423 index one. 424 425 -- Runtime Function: int __paritysi2 (int A) 426 -- Runtime Function: int __paritydi2 (long A) 427 -- Runtime Function: int __parityti2 (long long A) 428 These functions return the value zero if the number of bits set in 429 A is even, and the value one otherwise. 430 431 -- Runtime Function: int __popcountsi2 (int A) 432 -- Runtime Function: int __popcountdi2 (long A) 433 -- Runtime Function: int __popcountti2 (long long A) 434 These functions return the number of bits set in A. 435 436 -- Runtime Function: int32_t __bswapsi2 (int32_t A) 437 -- Runtime Function: int64_t __bswapdi2 (int64_t A) 438 These functions return the A byteswapped. 439 440 441 File: gccint.info, Node: Soft float library routines, Next: Decimal float library routines, Prev: Integer library routines, Up: Libgcc 442 443 4.2 Routines for floating point emulation 444 ========================================= 445 446 The software floating point library is used on machines which do not 447 have hardware support for floating point. It is also used whenever 448 `-msoft-float' is used to disable generation of floating point 449 instructions. (Not all targets support this switch.) 450 451 For compatibility with other compilers, the floating point emulation 452 routines can be renamed with the `DECLARE_LIBRARY_RENAMES' macro (*note 453 Library Calls::). In this section, the default names are used. 454 455 Presently the library does not support `XFmode', which is used for 456 `long double' on some architectures. 457 458 4.2.1 Arithmetic functions 459 -------------------------- 460 461 -- Runtime Function: float __addsf3 (float A, float B) 462 -- Runtime Function: double __adddf3 (double A, double B) 463 -- Runtime Function: long double __addtf3 (long double A, long double 464 B) 465 -- Runtime Function: long double __addxf3 (long double A, long double 466 B) 467 These functions return the sum of A and B. 468 469 -- Runtime Function: float __subsf3 (float A, float B) 470 -- Runtime Function: double __subdf3 (double A, double B) 471 -- Runtime Function: long double __subtf3 (long double A, long double 472 B) 473 -- Runtime Function: long double __subxf3 (long double A, long double 474 B) 475 These functions return the difference between B and A; that is, 476 A - B. 477 478 -- Runtime Function: float __mulsf3 (float A, float B) 479 -- Runtime Function: double __muldf3 (double A, double B) 480 -- Runtime Function: long double __multf3 (long double A, long double 481 B) 482 -- Runtime Function: long double __mulxf3 (long double A, long double 483 B) 484 These functions return the product of A and B. 485 486 -- Runtime Function: float __divsf3 (float A, float B) 487 -- Runtime Function: double __divdf3 (double A, double B) 488 -- Runtime Function: long double __divtf3 (long double A, long double 489 B) 490 -- Runtime Function: long double __divxf3 (long double A, long double 491 B) 492 These functions return the quotient of A and B; that is, A / B. 493 494 -- Runtime Function: float __negsf2 (float A) 495 -- Runtime Function: double __negdf2 (double A) 496 -- Runtime Function: long double __negtf2 (long double A) 497 -- Runtime Function: long double __negxf2 (long double A) 498 These functions return the negation of A. They simply flip the 499 sign bit, so they can produce negative zero and negative NaN. 500 501 4.2.2 Conversion functions 502 -------------------------- 503 504 -- Runtime Function: double __extendsfdf2 (float A) 505 -- Runtime Function: long double __extendsftf2 (float A) 506 -- Runtime Function: long double __extendsfxf2 (float A) 507 -- Runtime Function: long double __extenddftf2 (double A) 508 -- Runtime Function: long double __extenddfxf2 (double A) 509 These functions extend A to the wider mode of their return type. 510 511 -- Runtime Function: double __truncxfdf2 (long double A) 512 -- Runtime Function: double __trunctfdf2 (long double A) 513 -- Runtime Function: float __truncxfsf2 (long double A) 514 -- Runtime Function: float __trunctfsf2 (long double A) 515 -- Runtime Function: float __truncdfsf2 (double A) 516 These functions truncate A to the narrower mode of their return 517 type, rounding toward zero. 518 519 -- Runtime Function: int __fixsfsi (float A) 520 -- Runtime Function: int __fixdfsi (double A) 521 -- Runtime Function: int __fixtfsi (long double A) 522 -- Runtime Function: int __fixxfsi (long double A) 523 These functions convert A to a signed integer, rounding toward 524 zero. 525 526 -- Runtime Function: long __fixsfdi (float A) 527 -- Runtime Function: long __fixdfdi (double A) 528 -- Runtime Function: long __fixtfdi (long double A) 529 -- Runtime Function: long __fixxfdi (long double A) 530 These functions convert A to a signed long, rounding toward zero. 531 532 -- Runtime Function: long long __fixsfti (float A) 533 -- Runtime Function: long long __fixdfti (double A) 534 -- Runtime Function: long long __fixtfti (long double A) 535 -- Runtime Function: long long __fixxfti (long double A) 536 These functions convert A to a signed long long, rounding toward 537 zero. 538 539 -- Runtime Function: unsigned int __fixunssfsi (float A) 540 -- Runtime Function: unsigned int __fixunsdfsi (double A) 541 -- Runtime Function: unsigned int __fixunstfsi (long double A) 542 -- Runtime Function: unsigned int __fixunsxfsi (long double A) 543 These functions convert A to an unsigned integer, rounding toward 544 zero. Negative values all become zero. 545 546 -- Runtime Function: unsigned long __fixunssfdi (float A) 547 -- Runtime Function: unsigned long __fixunsdfdi (double A) 548 -- Runtime Function: unsigned long __fixunstfdi (long double A) 549 -- Runtime Function: unsigned long __fixunsxfdi (long double A) 550 These functions convert A to an unsigned long, rounding toward 551 zero. Negative values all become zero. 552 553 -- Runtime Function: unsigned long long __fixunssfti (float A) 554 -- Runtime Function: unsigned long long __fixunsdfti (double A) 555 -- Runtime Function: unsigned long long __fixunstfti (long double A) 556 -- Runtime Function: unsigned long long __fixunsxfti (long double A) 557 These functions convert A to an unsigned long long, rounding 558 toward zero. Negative values all become zero. 559 560 -- Runtime Function: float __floatsisf (int I) 561 -- Runtime Function: double __floatsidf (int I) 562 -- Runtime Function: long double __floatsitf (int I) 563 -- Runtime Function: long double __floatsixf (int I) 564 These functions convert I, a signed integer, to floating point. 565 566 -- Runtime Function: float __floatdisf (long I) 567 -- Runtime Function: double __floatdidf (long I) 568 -- Runtime Function: long double __floatditf (long I) 569 -- Runtime Function: long double __floatdixf (long I) 570 These functions convert I, a signed long, to floating point. 571 572 -- Runtime Function: float __floattisf (long long I) 573 -- Runtime Function: double __floattidf (long long I) 574 -- Runtime Function: long double __floattitf (long long I) 575 -- Runtime Function: long double __floattixf (long long I) 576 These functions convert I, a signed long long, to floating point. 577 578 -- Runtime Function: float __floatunsisf (unsigned int I) 579 -- Runtime Function: double __floatunsidf (unsigned int I) 580 -- Runtime Function: long double __floatunsitf (unsigned int I) 581 -- Runtime Function: long double __floatunsixf (unsigned int I) 582 These functions convert I, an unsigned integer, to floating point. 583 584 -- Runtime Function: float __floatundisf (unsigned long I) 585 -- Runtime Function: double __floatundidf (unsigned long I) 586 -- Runtime Function: long double __floatunditf (unsigned long I) 587 -- Runtime Function: long double __floatundixf (unsigned long I) 588 These functions convert I, an unsigned long, to floating point. 589 590 -- Runtime Function: float __floatuntisf (unsigned long long I) 591 -- Runtime Function: double __floatuntidf (unsigned long long I) 592 -- Runtime Function: long double __floatuntitf (unsigned long long I) 593 -- Runtime Function: long double __floatuntixf (unsigned long long I) 594 These functions convert I, an unsigned long long, to floating 595 point. 596 597 4.2.3 Comparison functions 598 -------------------------- 599 600 There are two sets of basic comparison functions. 601 602 -- Runtime Function: int __cmpsf2 (float A, float B) 603 -- Runtime Function: int __cmpdf2 (double A, double B) 604 -- Runtime Function: int __cmptf2 (long double A, long double B) 605 These functions calculate a <=> b. That is, if A is less than B, 606 they return -1; if A is greater than B, they return 1; and if A 607 and B are equal they return 0. If either argument is NaN they 608 return 1, but you should not rely on this; if NaN is a 609 possibility, use one of the higher-level comparison functions. 610 611 -- Runtime Function: int __unordsf2 (float A, float B) 612 -- Runtime Function: int __unorddf2 (double A, double B) 613 -- Runtime Function: int __unordtf2 (long double A, long double B) 614 These functions return a nonzero value if either argument is NaN, 615 otherwise 0. 616 617 There is also a complete group of higher level functions which 618 correspond directly to comparison operators. They implement the ISO C 619 semantics for floating-point comparisons, taking NaN into account. Pay 620 careful attention to the return values defined for each set. Under the 621 hood, all of these routines are implemented as 622 623 if (__unordXf2 (a, b)) 624 return E; 625 return __cmpXf2 (a, b); 626 627 where E is a constant chosen to give the proper behavior for NaN. 628 Thus, the meaning of the return value is different for each set. Do 629 not rely on this implementation; only the semantics documented below 630 are guaranteed. 631 632 -- Runtime Function: int __eqsf2 (float A, float B) 633 -- Runtime Function: int __eqdf2 (double A, double B) 634 -- Runtime Function: int __eqtf2 (long double A, long double B) 635 These functions return zero if neither argument is NaN, and A and 636 B are equal. 637 638 -- Runtime Function: int __nesf2 (float A, float B) 639 -- Runtime Function: int __nedf2 (double A, double B) 640 -- Runtime Function: int __netf2 (long double A, long double B) 641 These functions return a nonzero value if either argument is NaN, 642 or if A and B are unequal. 643 644 -- Runtime Function: int __gesf2 (float A, float B) 645 -- Runtime Function: int __gedf2 (double A, double B) 646 -- Runtime Function: int __getf2 (long double A, long double B) 647 These functions return a value greater than or equal to zero if 648 neither argument is NaN, and A is greater than or equal to B. 649 650 -- Runtime Function: int __ltsf2 (float A, float B) 651 -- Runtime Function: int __ltdf2 (double A, double B) 652 -- Runtime Function: int __lttf2 (long double A, long double B) 653 These functions return a value less than zero if neither argument 654 is NaN, and A is strictly less than B. 655 656 -- Runtime Function: int __lesf2 (float A, float B) 657 -- Runtime Function: int __ledf2 (double A, double B) 658 -- Runtime Function: int __letf2 (long double A, long double B) 659 These functions return a value less than or equal to zero if 660 neither argument is NaN, and A is less than or equal to B. 661 662 -- Runtime Function: int __gtsf2 (float A, float B) 663 -- Runtime Function: int __gtdf2 (double A, double B) 664 -- Runtime Function: int __gttf2 (long double A, long double B) 665 These functions return a value greater than zero if neither 666 argument is NaN, and A is strictly greater than B. 667 668 4.2.4 Other floating-point functions 669 ------------------------------------ 670 671 -- Runtime Function: float __powisf2 (float A, int B) 672 -- Runtime Function: double __powidf2 (double A, int B) 673 -- Runtime Function: long double __powitf2 (long double A, int B) 674 -- Runtime Function: long double __powixf2 (long double A, int B) 675 These functions convert raise A to the power B. 676 677 -- Runtime Function: complex float __mulsc3 (float A, float B, float 678 C, float D) 679 -- Runtime Function: complex double __muldc3 (double A, double B, 680 double C, double D) 681 -- Runtime Function: complex long double __multc3 (long double A, long 682 double B, long double C, long double D) 683 -- Runtime Function: complex long double __mulxc3 (long double A, long 684 double B, long double C, long double D) 685 These functions return the product of A + iB and C + iD, following 686 the rules of C99 Annex G. 687 688 -- Runtime Function: complex float __divsc3 (float A, float B, float 689 C, float D) 690 -- Runtime Function: complex double __divdc3 (double A, double B, 691 double C, double D) 692 -- Runtime Function: complex long double __divtc3 (long double A, long 693 double B, long double C, long double D) 694 -- Runtime Function: complex long double __divxc3 (long double A, long 695 double B, long double C, long double D) 696 These functions return the quotient of A + iB and C + iD (i.e., (A 697 + iB) / (C + iD)), following the rules of C99 Annex G. 698 699 700 File: gccint.info, Node: Decimal float library routines, Next: Fixed-point fractional library routines, Prev: Soft float library routines, Up: Libgcc 701 702 4.3 Routines for decimal floating point emulation 703 ================================================= 704 705 The software decimal floating point library implements IEEE 754-2008 706 decimal floating point arithmetic and is only activated on selected 707 targets. 708 709 The software decimal floating point library supports either DPD 710 (Densely Packed Decimal) or BID (Binary Integer Decimal) encoding as 711 selected at configure time. 712 713 4.3.1 Arithmetic functions 714 -------------------------- 715 716 -- Runtime Function: _Decimal32 __dpd_addsd3 (_Decimal32 A, _Decimal32 717 B) 718 -- Runtime Function: _Decimal32 __bid_addsd3 (_Decimal32 A, _Decimal32 719 B) 720 -- Runtime Function: _Decimal64 __dpd_adddd3 (_Decimal64 A, _Decimal64 721 B) 722 -- Runtime Function: _Decimal64 __bid_adddd3 (_Decimal64 A, _Decimal64 723 B) 724 -- Runtime Function: _Decimal128 __dpd_addtd3 (_Decimal128 A, 725 _Decimal128 B) 726 -- Runtime Function: _Decimal128 __bid_addtd3 (_Decimal128 A, 727 _Decimal128 B) 728 These functions return the sum of A and B. 729 730 -- Runtime Function: _Decimal32 __dpd_subsd3 (_Decimal32 A, _Decimal32 731 B) 732 -- Runtime Function: _Decimal32 __bid_subsd3 (_Decimal32 A, _Decimal32 733 B) 734 -- Runtime Function: _Decimal64 __dpd_subdd3 (_Decimal64 A, _Decimal64 735 B) 736 -- Runtime Function: _Decimal64 __bid_subdd3 (_Decimal64 A, _Decimal64 737 B) 738 -- Runtime Function: _Decimal128 __dpd_subtd3 (_Decimal128 A, 739 _Decimal128 B) 740 -- Runtime Function: _Decimal128 __bid_subtd3 (_Decimal128 A, 741 _Decimal128 B) 742 These functions return the difference between B and A; that is, 743 A - B. 744 745 -- Runtime Function: _Decimal32 __dpd_mulsd3 (_Decimal32 A, _Decimal32 746 B) 747 -- Runtime Function: _Decimal32 __bid_mulsd3 (_Decimal32 A, _Decimal32 748 B) 749 -- Runtime Function: _Decimal64 __dpd_muldd3 (_Decimal64 A, _Decimal64 750 B) 751 -- Runtime Function: _Decimal64 __bid_muldd3 (_Decimal64 A, _Decimal64 752 B) 753 -- Runtime Function: _Decimal128 __dpd_multd3 (_Decimal128 A, 754 _Decimal128 B) 755 -- Runtime Function: _Decimal128 __bid_multd3 (_Decimal128 A, 756 _Decimal128 B) 757 These functions return the product of A and B. 758 759 -- Runtime Function: _Decimal32 __dpd_divsd3 (_Decimal32 A, _Decimal32 760 B) 761 -- Runtime Function: _Decimal32 __bid_divsd3 (_Decimal32 A, _Decimal32 762 B) 763 -- Runtime Function: _Decimal64 __dpd_divdd3 (_Decimal64 A, _Decimal64 764 B) 765 -- Runtime Function: _Decimal64 __bid_divdd3 (_Decimal64 A, _Decimal64 766 B) 767 -- Runtime Function: _Decimal128 __dpd_divtd3 (_Decimal128 A, 768 _Decimal128 B) 769 -- Runtime Function: _Decimal128 __bid_divtd3 (_Decimal128 A, 770 _Decimal128 B) 771 These functions return the quotient of A and B; that is, A / B. 772 773 -- Runtime Function: _Decimal32 __dpd_negsd2 (_Decimal32 A) 774 -- Runtime Function: _Decimal32 __bid_negsd2 (_Decimal32 A) 775 -- Runtime Function: _Decimal64 __dpd_negdd2 (_Decimal64 A) 776 -- Runtime Function: _Decimal64 __bid_negdd2 (_Decimal64 A) 777 -- Runtime Function: _Decimal128 __dpd_negtd2 (_Decimal128 A) 778 -- Runtime Function: _Decimal128 __bid_negtd2 (_Decimal128 A) 779 These functions return the negation of A. They simply flip the 780 sign bit, so they can produce negative zero and negative NaN. 781 782 4.3.2 Conversion functions 783 -------------------------- 784 785 -- Runtime Function: _Decimal64 __dpd_extendsddd2 (_Decimal32 A) 786 -- Runtime Function: _Decimal64 __bid_extendsddd2 (_Decimal32 A) 787 -- Runtime Function: _Decimal128 __dpd_extendsdtd2 (_Decimal32 A) 788 -- Runtime Function: _Decimal128 __bid_extendsdtd2 (_Decimal32 A) 789 -- Runtime Function: _Decimal128 __dpd_extendddtd2 (_Decimal64 A) 790 -- Runtime Function: _Decimal128 __bid_extendddtd2 (_Decimal64 A) 791 -- Runtime Function: _Decimal32 __dpd_truncddsd2 (_Decimal64 A) 792 -- Runtime Function: _Decimal32 __bid_truncddsd2 (_Decimal64 A) 793 -- Runtime Function: _Decimal32 __dpd_trunctdsd2 (_Decimal128 A) 794 -- Runtime Function: _Decimal32 __bid_trunctdsd2 (_Decimal128 A) 795 -- Runtime Function: _Decimal64 __dpd_trunctddd2 (_Decimal128 A) 796 -- Runtime Function: _Decimal64 __bid_trunctddd2 (_Decimal128 A) 797 These functions convert the value A from one decimal floating type 798 to another. 799 800 -- Runtime Function: _Decimal64 __dpd_extendsfdd (float A) 801 -- Runtime Function: _Decimal64 __bid_extendsfdd (float A) 802 -- Runtime Function: _Decimal128 __dpd_extendsftd (float A) 803 -- Runtime Function: _Decimal128 __bid_extendsftd (float A) 804 -- Runtime Function: _Decimal128 __dpd_extenddftd (double A) 805 -- Runtime Function: _Decimal128 __bid_extenddftd (double A) 806 -- Runtime Function: _Decimal128 __dpd_extendxftd (long double A) 807 -- Runtime Function: _Decimal128 __bid_extendxftd (long double A) 808 -- Runtime Function: _Decimal32 __dpd_truncdfsd (double A) 809 -- Runtime Function: _Decimal32 __bid_truncdfsd (double A) 810 -- Runtime Function: _Decimal32 __dpd_truncxfsd (long double A) 811 -- Runtime Function: _Decimal32 __bid_truncxfsd (long double A) 812 -- Runtime Function: _Decimal32 __dpd_trunctfsd (long double A) 813 -- Runtime Function: _Decimal32 __bid_trunctfsd (long double A) 814 -- Runtime Function: _Decimal64 __dpd_truncxfdd (long double A) 815 -- Runtime Function: _Decimal64 __bid_truncxfdd (long double A) 816 -- Runtime Function: _Decimal64 __dpd_trunctfdd (long double A) 817 -- Runtime Function: _Decimal64 __bid_trunctfdd (long double A) 818 These functions convert the value of A from a binary floating type 819 to a decimal floating type of a different size. 820 821 -- Runtime Function: float __dpd_truncddsf (_Decimal64 A) 822 -- Runtime Function: float __bid_truncddsf (_Decimal64 A) 823 -- Runtime Function: float __dpd_trunctdsf (_Decimal128 A) 824 -- Runtime Function: float __bid_trunctdsf (_Decimal128 A) 825 -- Runtime Function: double __dpd_extendsddf (_Decimal32 A) 826 -- Runtime Function: double __bid_extendsddf (_Decimal32 A) 827 -- Runtime Function: double __dpd_trunctddf (_Decimal128 A) 828 -- Runtime Function: double __bid_trunctddf (_Decimal128 A) 829 -- Runtime Function: long double __dpd_extendsdxf (_Decimal32 A) 830 -- Runtime Function: long double __bid_extendsdxf (_Decimal32 A) 831 -- Runtime Function: long double __dpd_extendddxf (_Decimal64 A) 832 -- Runtime Function: long double __bid_extendddxf (_Decimal64 A) 833 -- Runtime Function: long double __dpd_trunctdxf (_Decimal128 A) 834 -- Runtime Function: long double __bid_trunctdxf (_Decimal128 A) 835 -- Runtime Function: long double __dpd_extendsdtf (_Decimal32 A) 836 -- Runtime Function: long double __bid_extendsdtf (_Decimal32 A) 837 -- Runtime Function: long double __dpd_extendddtf (_Decimal64 A) 838 -- Runtime Function: long double __bid_extendddtf (_Decimal64 A) 839 These functions convert the value of A from a decimal floating type 840 to a binary floating type of a different size. 841 842 -- Runtime Function: _Decimal32 __dpd_extendsfsd (float A) 843 -- Runtime Function: _Decimal32 __bid_extendsfsd (float A) 844 -- Runtime Function: _Decimal64 __dpd_extenddfdd (double A) 845 -- Runtime Function: _Decimal64 __bid_extenddfdd (double A) 846 -- Runtime Function: _Decimal128 __dpd_extendtftd (long double A) 847 -- Runtime Function: _Decimal128 __bid_extendtftd (long double A) 848 -- Runtime Function: float __dpd_truncsdsf (_Decimal32 A) 849 -- Runtime Function: float __bid_truncsdsf (_Decimal32 A) 850 -- Runtime Function: double __dpd_truncdddf (_Decimal64 A) 851 -- Runtime Function: double __bid_truncdddf (_Decimal64 A) 852 -- Runtime Function: long double __dpd_trunctdtf (_Decimal128 A) 853 -- Runtime Function: long double __bid_trunctdtf (_Decimal128 A) 854 These functions convert the value of A between decimal and binary 855 floating types of the same size. 856 857 -- Runtime Function: int __dpd_fixsdsi (_Decimal32 A) 858 -- Runtime Function: int __bid_fixsdsi (_Decimal32 A) 859 -- Runtime Function: int __dpd_fixddsi (_Decimal64 A) 860 -- Runtime Function: int __bid_fixddsi (_Decimal64 A) 861 -- Runtime Function: int __dpd_fixtdsi (_Decimal128 A) 862 -- Runtime Function: int __bid_fixtdsi (_Decimal128 A) 863 These functions convert A to a signed integer. 864 865 -- Runtime Function: long __dpd_fixsddi (_Decimal32 A) 866 -- Runtime Function: long __bid_fixsddi (_Decimal32 A) 867 -- Runtime Function: long __dpd_fixdddi (_Decimal64 A) 868 -- Runtime Function: long __bid_fixdddi (_Decimal64 A) 869 -- Runtime Function: long __dpd_fixtddi (_Decimal128 A) 870 -- Runtime Function: long __bid_fixtddi (_Decimal128 A) 871 These functions convert A to a signed long. 872 873 -- Runtime Function: unsigned int __dpd_fixunssdsi (_Decimal32 A) 874 -- Runtime Function: unsigned int __bid_fixunssdsi (_Decimal32 A) 875 -- Runtime Function: unsigned int __dpd_fixunsddsi (_Decimal64 A) 876 -- Runtime Function: unsigned int __bid_fixunsddsi (_Decimal64 A) 877 -- Runtime Function: unsigned int __dpd_fixunstdsi (_Decimal128 A) 878 -- Runtime Function: unsigned int __bid_fixunstdsi (_Decimal128 A) 879 These functions convert A to an unsigned integer. Negative values 880 all become zero. 881 882 -- Runtime Function: unsigned long __dpd_fixunssddi (_Decimal32 A) 883 -- Runtime Function: unsigned long __bid_fixunssddi (_Decimal32 A) 884 -- Runtime Function: unsigned long __dpd_fixunsdddi (_Decimal64 A) 885 -- Runtime Function: unsigned long __bid_fixunsdddi (_Decimal64 A) 886 -- Runtime Function: unsigned long __dpd_fixunstddi (_Decimal128 A) 887 -- Runtime Function: unsigned long __bid_fixunstddi (_Decimal128 A) 888 These functions convert A to an unsigned long. Negative values 889 all become zero. 890 891 -- Runtime Function: _Decimal32 __dpd_floatsisd (int I) 892 -- Runtime Function: _Decimal32 __bid_floatsisd (int I) 893 -- Runtime Function: _Decimal64 __dpd_floatsidd (int I) 894 -- Runtime Function: _Decimal64 __bid_floatsidd (int I) 895 -- Runtime Function: _Decimal128 __dpd_floatsitd (int I) 896 -- Runtime Function: _Decimal128 __bid_floatsitd (int I) 897 These functions convert I, a signed integer, to decimal floating 898 point. 899 900 -- Runtime Function: _Decimal32 __dpd_floatdisd (long I) 901 -- Runtime Function: _Decimal32 __bid_floatdisd (long I) 902 -- Runtime Function: _Decimal64 __dpd_floatdidd (long I) 903 -- Runtime Function: _Decimal64 __bid_floatdidd (long I) 904 -- Runtime Function: _Decimal128 __dpd_floatditd (long I) 905 -- Runtime Function: _Decimal128 __bid_floatditd (long I) 906 These functions convert I, a signed long, to decimal floating 907 point. 908 909 -- Runtime Function: _Decimal32 __dpd_floatunssisd (unsigned int I) 910 -- Runtime Function: _Decimal32 __bid_floatunssisd (unsigned int I) 911 -- Runtime Function: _Decimal64 __dpd_floatunssidd (unsigned int I) 912 -- Runtime Function: _Decimal64 __bid_floatunssidd (unsigned int I) 913 -- Runtime Function: _Decimal128 __dpd_floatunssitd (unsigned int I) 914 -- Runtime Function: _Decimal128 __bid_floatunssitd (unsigned int I) 915 These functions convert I, an unsigned integer, to decimal 916 floating point. 917 918 -- Runtime Function: _Decimal32 __dpd_floatunsdisd (unsigned long I) 919 -- Runtime Function: _Decimal32 __bid_floatunsdisd (unsigned long I) 920 -- Runtime Function: _Decimal64 __dpd_floatunsdidd (unsigned long I) 921 -- Runtime Function: _Decimal64 __bid_floatunsdidd (unsigned long I) 922 -- Runtime Function: _Decimal128 __dpd_floatunsditd (unsigned long I) 923 -- Runtime Function: _Decimal128 __bid_floatunsditd (unsigned long I) 924 These functions convert I, an unsigned long, to decimal floating 925 point. 926 927 4.3.3 Comparison functions 928 -------------------------- 929 930 -- Runtime Function: int __dpd_unordsd2 (_Decimal32 A, _Decimal32 B) 931 -- Runtime Function: int __bid_unordsd2 (_Decimal32 A, _Decimal32 B) 932 -- Runtime Function: int __dpd_unorddd2 (_Decimal64 A, _Decimal64 B) 933 -- Runtime Function: int __bid_unorddd2 (_Decimal64 A, _Decimal64 B) 934 -- Runtime Function: int __dpd_unordtd2 (_Decimal128 A, _Decimal128 B) 935 -- Runtime Function: int __bid_unordtd2 (_Decimal128 A, _Decimal128 B) 936 These functions return a nonzero value if either argument is NaN, 937 otherwise 0. 938 939 There is also a complete group of higher level functions which 940 correspond directly to comparison operators. They implement the ISO C 941 semantics for floating-point comparisons, taking NaN into account. Pay 942 careful attention to the return values defined for each set. Under the 943 hood, all of these routines are implemented as 944 945 if (__bid_unordXd2 (a, b)) 946 return E; 947 return __bid_cmpXd2 (a, b); 948 949 where E is a constant chosen to give the proper behavior for NaN. 950 Thus, the meaning of the return value is different for each set. Do 951 not rely on this implementation; only the semantics documented below 952 are guaranteed. 953 954 -- Runtime Function: int __dpd_eqsd2 (_Decimal32 A, _Decimal32 B) 955 -- Runtime Function: int __bid_eqsd2 (_Decimal32 A, _Decimal32 B) 956 -- Runtime Function: int __dpd_eqdd2 (_Decimal64 A, _Decimal64 B) 957 -- Runtime Function: int __bid_eqdd2 (_Decimal64 A, _Decimal64 B) 958 -- Runtime Function: int __dpd_eqtd2 (_Decimal128 A, _Decimal128 B) 959 -- Runtime Function: int __bid_eqtd2 (_Decimal128 A, _Decimal128 B) 960 These functions return zero if neither argument is NaN, and A and 961 B are equal. 962 963 -- Runtime Function: int __dpd_nesd2 (_Decimal32 A, _Decimal32 B) 964 -- Runtime Function: int __bid_nesd2 (_Decimal32 A, _Decimal32 B) 965 -- Runtime Function: int __dpd_nedd2 (_Decimal64 A, _Decimal64 B) 966 -- Runtime Function: int __bid_nedd2 (_Decimal64 A, _Decimal64 B) 967 -- Runtime Function: int __dpd_netd2 (_Decimal128 A, _Decimal128 B) 968 -- Runtime Function: int __bid_netd2 (_Decimal128 A, _Decimal128 B) 969 These functions return a nonzero value if either argument is NaN, 970 or if A and B are unequal. 971 972 -- Runtime Function: int __dpd_gesd2 (_Decimal32 A, _Decimal32 B) 973 -- Runtime Function: int __bid_gesd2 (_Decimal32 A, _Decimal32 B) 974 -- Runtime Function: int __dpd_gedd2 (_Decimal64 A, _Decimal64 B) 975 -- Runtime Function: int __bid_gedd2 (_Decimal64 A, _Decimal64 B) 976 -- Runtime Function: int __dpd_getd2 (_Decimal128 A, _Decimal128 B) 977 -- Runtime Function: int __bid_getd2 (_Decimal128 A, _Decimal128 B) 978 These functions return a value greater than or equal to zero if 979 neither argument is NaN, and A is greater than or equal to B. 980 981 -- Runtime Function: int __dpd_ltsd2 (_Decimal32 A, _Decimal32 B) 982 -- Runtime Function: int __bid_ltsd2 (_Decimal32 A, _Decimal32 B) 983 -- Runtime Function: int __dpd_ltdd2 (_Decimal64 A, _Decimal64 B) 984 -- Runtime Function: int __bid_ltdd2 (_Decimal64 A, _Decimal64 B) 985 -- Runtime Function: int __dpd_lttd2 (_Decimal128 A, _Decimal128 B) 986 -- Runtime Function: int __bid_lttd2 (_Decimal128 A, _Decimal128 B) 987 These functions return a value less than zero if neither argument 988 is NaN, and A is strictly less than B. 989 990 -- Runtime Function: int __dpd_lesd2 (_Decimal32 A, _Decimal32 B) 991 -- Runtime Function: int __bid_lesd2 (_Decimal32 A, _Decimal32 B) 992 -- Runtime Function: int __dpd_ledd2 (_Decimal64 A, _Decimal64 B) 993 -- Runtime Function: int __bid_ledd2 (_Decimal64 A, _Decimal64 B) 994 -- Runtime Function: int __dpd_letd2 (_Decimal128 A, _Decimal128 B) 995 -- Runtime Function: int __bid_letd2 (_Decimal128 A, _Decimal128 B) 996 These functions return a value less than or equal to zero if 997 neither argument is NaN, and A is less than or equal to B. 998 999 -- Runtime Function: int __dpd_gtsd2 (_Decimal32 A, _Decimal32 B) 1000 -- Runtime Function: int __bid_gtsd2 (_Decimal32 A, _Decimal32 B) 1001 -- Runtime Function: int __dpd_gtdd2 (_Decimal64 A, _Decimal64 B) 1002 -- Runtime Function: int __bid_gtdd2 (_Decimal64 A, _Decimal64 B) 1003 -- Runtime Function: int __dpd_gttd2 (_Decimal128 A, _Decimal128 B) 1004 -- Runtime Function: int __bid_gttd2 (_Decimal128 A, _Decimal128 B) 1005 These functions return a value greater than zero if neither 1006 argument is NaN, and A is strictly greater than B. 1007 1008 1009 File: gccint.info, Node: Fixed-point fractional library routines, Next: Exception handling routines, Prev: Decimal float library routines, Up: Libgcc 1010 1011 4.4 Routines for fixed-point fractional emulation 1012 ================================================= 1013 1014 The software fixed-point library implements fixed-point fractional 1015 arithmetic, and is only activated on selected targets. 1016 1017 For ease of comprehension `fract' is an alias for the `_Fract' type, 1018 `accum' an alias for `_Accum', and `sat' an alias for `_Sat'. 1019 1020 For illustrative purposes, in this section the fixed-point fractional 1021 type `short fract' is assumed to correspond to machine mode `QQmode'; 1022 `unsigned short fract' to `UQQmode'; `fract' to `HQmode'; 1023 `unsigned fract' to `UHQmode'; `long fract' to `SQmode'; 1024 `unsigned long fract' to `USQmode'; `long long fract' to `DQmode'; and 1025 `unsigned long long fract' to `UDQmode'. Similarly the fixed-point 1026 accumulator type `short accum' corresponds to `HAmode'; 1027 `unsigned short accum' to `UHAmode'; `accum' to `SAmode'; 1028 `unsigned accum' to `USAmode'; `long accum' to `DAmode'; 1029 `unsigned long accum' to `UDAmode'; `long long accum' to `TAmode'; and 1030 `unsigned long long accum' to `UTAmode'. 1031 1032 4.4.1 Arithmetic functions 1033 -------------------------- 1034 1035 -- Runtime Function: short fract __addqq3 (short fract A, short fract 1036 B) 1037 -- Runtime Function: fract __addhq3 (fract A, fract B) 1038 -- Runtime Function: long fract __addsq3 (long fract A, long fract B) 1039 -- Runtime Function: long long fract __adddq3 (long long fract A, long 1040 long fract B) 1041 -- Runtime Function: unsigned short fract __adduqq3 (unsigned short 1042 fract A, unsigned short fract B) 1043 -- Runtime Function: unsigned fract __adduhq3 (unsigned fract A, 1044 unsigned fract B) 1045 -- Runtime Function: unsigned long fract __addusq3 (unsigned long 1046 fract A, unsigned long fract B) 1047 -- Runtime Function: unsigned long long fract __addudq3 (unsigned long 1048 long fract A, unsigned long long fract B) 1049 -- Runtime Function: short accum __addha3 (short accum A, short accum 1050 B) 1051 -- Runtime Function: accum __addsa3 (accum A, accum B) 1052 -- Runtime Function: long accum __addda3 (long accum A, long accum B) 1053 -- Runtime Function: long long accum __addta3 (long long accum A, long 1054 long accum B) 1055 -- Runtime Function: unsigned short accum __adduha3 (unsigned short 1056 accum A, unsigned short accum B) 1057 -- Runtime Function: unsigned accum __addusa3 (unsigned accum A, 1058 unsigned accum B) 1059 -- Runtime Function: unsigned long accum __adduda3 (unsigned long 1060 accum A, unsigned long accum B) 1061 -- Runtime Function: unsigned long long accum __adduta3 (unsigned long 1062 long accum A, unsigned long long accum B) 1063 These functions return the sum of A and B. 1064 1065 -- Runtime Function: short fract __ssaddqq3 (short fract A, short 1066 fract B) 1067 -- Runtime Function: fract __ssaddhq3 (fract A, fract B) 1068 -- Runtime Function: long fract __ssaddsq3 (long fract A, long fract B) 1069 -- Runtime Function: long long fract __ssadddq3 (long long fract A, 1070 long long fract B) 1071 -- Runtime Function: short accum __ssaddha3 (short accum A, short 1072 accum B) 1073 -- Runtime Function: accum __ssaddsa3 (accum A, accum B) 1074 -- Runtime Function: long accum __ssaddda3 (long accum A, long accum B) 1075 -- Runtime Function: long long accum __ssaddta3 (long long accum A, 1076 long long accum B) 1077 These functions return the sum of A and B with signed saturation. 1078 1079 -- Runtime Function: unsigned short fract __usadduqq3 (unsigned short 1080 fract A, unsigned short fract B) 1081 -- Runtime Function: unsigned fract __usadduhq3 (unsigned fract A, 1082 unsigned fract B) 1083 -- Runtime Function: unsigned long fract __usaddusq3 (unsigned long 1084 fract A, unsigned long fract B) 1085 -- Runtime Function: unsigned long long fract __usaddudq3 (unsigned 1086 long long fract A, unsigned long long fract B) 1087 -- Runtime Function: unsigned short accum __usadduha3 (unsigned short 1088 accum A, unsigned short accum B) 1089 -- Runtime Function: unsigned accum __usaddusa3 (unsigned accum A, 1090 unsigned accum B) 1091 -- Runtime Function: unsigned long accum __usadduda3 (unsigned long 1092 accum A, unsigned long accum B) 1093 -- Runtime Function: unsigned long long accum __usadduta3 (unsigned 1094 long long accum A, unsigned long long accum B) 1095 These functions return the sum of A and B with unsigned saturation. 1096 1097 -- Runtime Function: short fract __subqq3 (short fract A, short fract 1098 B) 1099 -- Runtime Function: fract __subhq3 (fract A, fract B) 1100 -- Runtime Function: long fract __subsq3 (long fract A, long fract B) 1101 -- Runtime Function: long long fract __subdq3 (long long fract A, long 1102 long fract B) 1103 -- Runtime Function: unsigned short fract __subuqq3 (unsigned short 1104 fract A, unsigned short fract B) 1105 -- Runtime Function: unsigned fract __subuhq3 (unsigned fract A, 1106 unsigned fract B) 1107 -- Runtime Function: unsigned long fract __subusq3 (unsigned long 1108 fract A, unsigned long fract B) 1109 -- Runtime Function: unsigned long long fract __subudq3 (unsigned long 1110 long fract A, unsigned long long fract B) 1111 -- Runtime Function: short accum __subha3 (short accum A, short accum 1112 B) 1113 -- Runtime Function: accum __subsa3 (accum A, accum B) 1114 -- Runtime Function: long accum __subda3 (long accum A, long accum B) 1115 -- Runtime Function: long long accum __subta3 (long long accum A, long 1116 long accum B) 1117 -- Runtime Function: unsigned short accum __subuha3 (unsigned short 1118 accum A, unsigned short accum B) 1119 -- Runtime Function: unsigned accum __subusa3 (unsigned accum A, 1120 unsigned accum B) 1121 -- Runtime Function: unsigned long accum __subuda3 (unsigned long 1122 accum A, unsigned long accum B) 1123 -- Runtime Function: unsigned long long accum __subuta3 (unsigned long 1124 long accum A, unsigned long long accum B) 1125 These functions return the difference of A and B; that is, `A - B'. 1126 1127 -- Runtime Function: short fract __sssubqq3 (short fract A, short 1128 fract B) 1129 -- Runtime Function: fract __sssubhq3 (fract A, fract B) 1130 -- Runtime Function: long fract __sssubsq3 (long fract A, long fract B) 1131 -- Runtime Function: long long fract __sssubdq3 (long long fract A, 1132 long long fract B) 1133 -- Runtime Function: short accum __sssubha3 (short accum A, short 1134 accum B) 1135 -- Runtime Function: accum __sssubsa3 (accum A, accum B) 1136 -- Runtime Function: long accum __sssubda3 (long accum A, long accum B) 1137 -- Runtime Function: long long accum __sssubta3 (long long accum A, 1138 long long accum B) 1139 These functions return the difference of A and B with signed 1140 saturation; that is, `A - B'. 1141 1142 -- Runtime Function: unsigned short fract __ussubuqq3 (unsigned short 1143 fract A, unsigned short fract B) 1144 -- Runtime Function: unsigned fract __ussubuhq3 (unsigned fract A, 1145 unsigned fract B) 1146 -- Runtime Function: unsigned long fract __ussubusq3 (unsigned long 1147 fract A, unsigned long fract B) 1148 -- Runtime Function: unsigned long long fract __ussubudq3 (unsigned 1149 long long fract A, unsigned long long fract B) 1150 -- Runtime Function: unsigned short accum __ussubuha3 (unsigned short 1151 accum A, unsigned short accum B) 1152 -- Runtime Function: unsigned accum __ussubusa3 (unsigned accum A, 1153 unsigned accum B) 1154 -- Runtime Function: unsigned long accum __ussubuda3 (unsigned long 1155 accum A, unsigned long accum B) 1156 -- Runtime Function: unsigned long long accum __ussubuta3 (unsigned 1157 long long accum A, unsigned long long accum B) 1158 These functions return the difference of A and B with unsigned 1159 saturation; that is, `A - B'. 1160 1161 -- Runtime Function: short fract __mulqq3 (short fract A, short fract 1162 B) 1163 -- Runtime Function: fract __mulhq3 (fract A, fract B) 1164 -- Runtime Function: long fract __mulsq3 (long fract A, long fract B) 1165 -- Runtime Function: long long fract __muldq3 (long long fract A, long 1166 long fract B) 1167 -- Runtime Function: unsigned short fract __muluqq3 (unsigned short 1168 fract A, unsigned short fract B) 1169 -- Runtime Function: unsigned fract __muluhq3 (unsigned fract A, 1170 unsigned fract B) 1171 -- Runtime Function: unsigned long fract __mulusq3 (unsigned long 1172 fract A, unsigned long fract B) 1173 -- Runtime Function: unsigned long long fract __muludq3 (unsigned long 1174 long fract A, unsigned long long fract B) 1175 -- Runtime Function: short accum __mulha3 (short accum A, short accum 1176 B) 1177 -- Runtime Function: accum __mulsa3 (accum A, accum B) 1178 -- Runtime Function: long accum __mulda3 (long accum A, long accum B) 1179 -- Runtime Function: long long accum __multa3 (long long accum A, long 1180 long accum B) 1181 -- Runtime Function: unsigned short accum __muluha3 (unsigned short 1182 accum A, unsigned short accum B) 1183 -- Runtime Function: unsigned accum __mulusa3 (unsigned accum A, 1184 unsigned accum B) 1185 -- Runtime Function: unsigned long accum __muluda3 (unsigned long 1186 accum A, unsigned long accum B) 1187 -- Runtime Function: unsigned long long accum __muluta3 (unsigned long 1188 long accum A, unsigned long long accum B) 1189 These functions return the product of A and B. 1190 1191 -- Runtime Function: short fract __ssmulqq3 (short fract A, short 1192 fract B) 1193 -- Runtime Function: fract __ssmulhq3 (fract A, fract B) 1194 -- Runtime Function: long fract __ssmulsq3 (long fract A, long fract B) 1195 -- Runtime Function: long long fract __ssmuldq3 (long long fract A, 1196 long long fract B) 1197 -- Runtime Function: short accum __ssmulha3 (short accum A, short 1198 accum B) 1199 -- Runtime Function: accum __ssmulsa3 (accum A, accum B) 1200 -- Runtime Function: long accum __ssmulda3 (long accum A, long accum B) 1201 -- Runtime Function: long long accum __ssmulta3 (long long accum A, 1202 long long accum B) 1203 These functions return the product of A and B with signed 1204 saturation. 1205 1206 -- Runtime Function: unsigned short fract __usmuluqq3 (unsigned short 1207 fract A, unsigned short fract B) 1208 -- Runtime Function: unsigned fract __usmuluhq3 (unsigned fract A, 1209 unsigned fract B) 1210 -- Runtime Function: unsigned long fract __usmulusq3 (unsigned long 1211 fract A, unsigned long fract B) 1212 -- Runtime Function: unsigned long long fract __usmuludq3 (unsigned 1213 long long fract A, unsigned long long fract B) 1214 -- Runtime Function: unsigned short accum __usmuluha3 (unsigned short 1215 accum A, unsigned short accum B) 1216 -- Runtime Function: unsigned accum __usmulusa3 (unsigned accum A, 1217 unsigned accum B) 1218 -- Runtime Function: unsigned long accum __usmuluda3 (unsigned long 1219 accum A, unsigned long accum B) 1220 -- Runtime Function: unsigned long long accum __usmuluta3 (unsigned 1221 long long accum A, unsigned long long accum B) 1222 These functions return the product of A and B with unsigned 1223 saturation. 1224 1225 -- Runtime Function: short fract __divqq3 (short fract A, short fract 1226 B) 1227 -- Runtime Function: fract __divhq3 (fract A, fract B) 1228 -- Runtime Function: long fract __divsq3 (long fract A, long fract B) 1229 -- Runtime Function: long long fract __divdq3 (long long fract A, long 1230 long fract B) 1231 -- Runtime Function: short accum __divha3 (short accum A, short accum 1232 B) 1233 -- Runtime Function: accum __divsa3 (accum A, accum B) 1234 -- Runtime Function: long accum __divda3 (long accum A, long accum B) 1235 -- Runtime Function: long long accum __divta3 (long long accum A, long 1236 long accum B) 1237 These functions return the quotient of the signed division of A 1238 and B. 1239 1240 -- Runtime Function: unsigned short fract __udivuqq3 (unsigned short 1241 fract A, unsigned short fract B) 1242 -- Runtime Function: unsigned fract __udivuhq3 (unsigned fract A, 1243 unsigned fract B) 1244 -- Runtime Function: unsigned long fract __udivusq3 (unsigned long 1245 fract A, unsigned long fract B) 1246 -- Runtime Function: unsigned long long fract __udivudq3 (unsigned 1247 long long fract A, unsigned long long fract B) 1248 -- Runtime Function: unsigned short accum __udivuha3 (unsigned short 1249 accum A, unsigned short accum B) 1250 -- Runtime Function: unsigned accum __udivusa3 (unsigned accum A, 1251 unsigned accum B) 1252 -- Runtime Function: unsigned long accum __udivuda3 (unsigned long 1253 accum A, unsigned long accum B) 1254 -- Runtime Function: unsigned long long accum __udivuta3 (unsigned 1255 long long accum A, unsigned long long accum B) 1256 These functions return the quotient of the unsigned division of A 1257 and B. 1258 1259 -- Runtime Function: short fract __ssdivqq3 (short fract A, short 1260 fract B) 1261 -- Runtime Function: fract __ssdivhq3 (fract A, fract B) 1262 -- Runtime Function: long fract __ssdivsq3 (long fract A, long fract B) 1263 -- Runtime Function: long long fract __ssdivdq3 (long long fract A, 1264 long long fract B) 1265 -- Runtime Function: short accum __ssdivha3 (short accum A, short 1266 accum B) 1267 -- Runtime Function: accum __ssdivsa3 (accum A, accum B) 1268 -- Runtime Function: long accum __ssdivda3 (long accum A, long accum B) 1269 -- Runtime Function: long long accum __ssdivta3 (long long accum A, 1270 long long accum B) 1271 These functions return the quotient of the signed division of A 1272 and B with signed saturation. 1273 1274 -- Runtime Function: unsigned short fract __usdivuqq3 (unsigned short 1275 fract A, unsigned short fract B) 1276 -- Runtime Function: unsigned fract __usdivuhq3 (unsigned fract A, 1277 unsigned fract B) 1278 -- Runtime Function: unsigned long fract __usdivusq3 (unsigned long 1279 fract A, unsigned long fract B) 1280 -- Runtime Function: unsigned long long fract __usdivudq3 (unsigned 1281 long long fract A, unsigned long long fract B) 1282 -- Runtime Function: unsigned short accum __usdivuha3 (unsigned short 1283 accum A, unsigned short accum B) 1284 -- Runtime Function: unsigned accum __usdivusa3 (unsigned accum A, 1285 unsigned accum B) 1286 -- Runtime Function: unsigned long accum __usdivuda3 (unsigned long 1287 accum A, unsigned long accum B) 1288 -- Runtime Function: unsigned long long accum __usdivuta3 (unsigned 1289 long long accum A, unsigned long long accum B) 1290 These functions return the quotient of the unsigned division of A 1291 and B with unsigned saturation. 1292 1293 -- Runtime Function: short fract __negqq2 (short fract A) 1294 -- Runtime Function: fract __neghq2 (fract A) 1295 -- Runtime Function: long fract __negsq2 (long fract A) 1296 -- Runtime Function: long long fract __negdq2 (long long fract A) 1297 -- Runtime Function: unsigned short fract __neguqq2 (unsigned short 1298 fract A) 1299 -- Runtime Function: unsigned fract __neguhq2 (unsigned fract A) 1300 -- Runtime Function: unsigned long fract __negusq2 (unsigned long 1301 fract A) 1302 -- Runtime Function: unsigned long long fract __negudq2 (unsigned long 1303 long fract A) 1304 -- Runtime Function: short accum __negha2 (short accum A) 1305 -- Runtime Function: accum __negsa2 (accum A) 1306 -- Runtime Function: long accum __negda2 (long accum A) 1307 -- Runtime Function: long long accum __negta2 (long long accum A) 1308 -- Runtime Function: unsigned short accum __neguha2 (unsigned short 1309 accum A) 1310 -- Runtime Function: unsigned accum __negusa2 (unsigned accum A) 1311 -- Runtime Function: unsigned long accum __neguda2 (unsigned long 1312 accum A) 1313 -- Runtime Function: unsigned long long accum __neguta2 (unsigned long 1314 long accum A) 1315 These functions return the negation of A. 1316 1317 -- Runtime Function: short fract __ssnegqq2 (short fract A) 1318 -- Runtime Function: fract __ssneghq2 (fract A) 1319 -- Runtime Function: long fract __ssnegsq2 (long fract A) 1320 -- Runtime Function: long long fract __ssnegdq2 (long long fract A) 1321 -- Runtime Function: short accum __ssnegha2 (short accum A) 1322 -- Runtime Function: accum __ssnegsa2 (accum A) 1323 -- Runtime Function: long accum __ssnegda2 (long accum A) 1324 -- Runtime Function: long long accum __ssnegta2 (long long accum A) 1325 These functions return the negation of A with signed saturation. 1326 1327 -- Runtime Function: unsigned short fract __usneguqq2 (unsigned short 1328 fract A) 1329 -- Runtime Function: unsigned fract __usneguhq2 (unsigned fract A) 1330 -- Runtime Function: unsigned long fract __usnegusq2 (unsigned long 1331 fract A) 1332 -- Runtime Function: unsigned long long fract __usnegudq2 (unsigned 1333 long long fract A) 1334 -- Runtime Function: unsigned short accum __usneguha2 (unsigned short 1335 accum A) 1336 -- Runtime Function: unsigned accum __usnegusa2 (unsigned accum A) 1337 -- Runtime Function: unsigned long accum __usneguda2 (unsigned long 1338 accum A) 1339 -- Runtime Function: unsigned long long accum __usneguta2 (unsigned 1340 long long accum A) 1341 These functions return the negation of A with unsigned saturation. 1342 1343 -- Runtime Function: short fract __ashlqq3 (short fract A, int B) 1344 -- Runtime Function: fract __ashlhq3 (fract A, int B) 1345 -- Runtime Function: long fract __ashlsq3 (long fract A, int B) 1346 -- Runtime Function: long long fract __ashldq3 (long long fract A, int 1347 B) 1348 -- Runtime Function: unsigned short fract __ashluqq3 (unsigned short 1349 fract A, int B) 1350 -- Runtime Function: unsigned fract __ashluhq3 (unsigned fract A, int 1351 B) 1352 -- Runtime Function: unsigned long fract __ashlusq3 (unsigned long 1353 fract A, int B) 1354 -- Runtime Function: unsigned long long fract __ashludq3 (unsigned 1355 long long fract A, int B) 1356 -- Runtime Function: short accum __ashlha3 (short accum A, int B) 1357 -- Runtime Function: accum __ashlsa3 (accum A, int B) 1358 -- Runtime Function: long accum __ashlda3 (long accum A, int B) 1359 -- Runtime Function: long long accum __ashlta3 (long long accum A, int 1360 B) 1361 -- Runtime Function: unsigned short accum __ashluha3 (unsigned short 1362 accum A, int B) 1363 -- Runtime Function: unsigned accum __ashlusa3 (unsigned accum A, int 1364 B) 1365 -- Runtime Function: unsigned long accum __ashluda3 (unsigned long 1366 accum A, int B) 1367 -- Runtime Function: unsigned long long accum __ashluta3 (unsigned 1368 long long accum A, int B) 1369 These functions return the result of shifting A left by B bits. 1370 1371 -- Runtime Function: short fract __ashrqq3 (short fract A, int B) 1372 -- Runtime Function: fract __ashrhq3 (fract A, int B) 1373 -- Runtime Function: long fract __ashrsq3 (long fract A, int B) 1374 -- Runtime Function: long long fract __ashrdq3 (long long fract A, int 1375 B) 1376 -- Runtime Function: short accum __ashrha3 (short accum A, int B) 1377 -- Runtime Function: accum __ashrsa3 (accum A, int B) 1378 -- Runtime Function: long accum __ashrda3 (long accum A, int B) 1379 -- Runtime Function: long long accum __ashrta3 (long long accum A, int 1380 B) 1381 These functions return the result of arithmetically shifting A 1382 right by B bits. 1383 1384 -- Runtime Function: unsigned short fract __lshruqq3 (unsigned short 1385 fract A, int B) 1386 -- Runtime Function: unsigned fract __lshruhq3 (unsigned fract A, int 1387 B) 1388 -- Runtime Function: unsigned long fract __lshrusq3 (unsigned long 1389 fract A, int B) 1390 -- Runtime Function: unsigned long long fract __lshrudq3 (unsigned 1391 long long fract A, int B) 1392 -- Runtime Function: unsigned short accum __lshruha3 (unsigned short 1393 accum A, int B) 1394 -- Runtime Function: unsigned accum __lshrusa3 (unsigned accum A, int 1395 B) 1396 -- Runtime Function: unsigned long accum __lshruda3 (unsigned long 1397 accum A, int B) 1398 -- Runtime Function: unsigned long long accum __lshruta3 (unsigned 1399 long long accum A, int B) 1400 These functions return the result of logically shifting A right by 1401 B bits. 1402 1403 -- Runtime Function: fract __ssashlhq3 (fract A, int B) 1404 -- Runtime Function: long fract __ssashlsq3 (long fract A, int B) 1405 -- Runtime Function: long long fract __ssashldq3 (long long fract A, 1406 int B) 1407 -- Runtime Function: short accum __ssashlha3 (short accum A, int B) 1408 -- Runtime Function: accum __ssashlsa3 (accum A, int B) 1409 -- Runtime Function: long accum __ssashlda3 (long accum A, int B) 1410 -- Runtime Function: long long accum __ssashlta3 (long long accum A, 1411 int B) 1412 These functions return the result of shifting A left by B bits 1413 with signed saturation. 1414 1415 -- Runtime Function: unsigned short fract __usashluqq3 (unsigned short 1416 fract A, int B) 1417 -- Runtime Function: unsigned fract __usashluhq3 (unsigned fract A, 1418 int B) 1419 -- Runtime Function: unsigned long fract __usashlusq3 (unsigned long 1420 fract A, int B) 1421 -- Runtime Function: unsigned long long fract __usashludq3 (unsigned 1422 long long fract A, int B) 1423 -- Runtime Function: unsigned short accum __usashluha3 (unsigned short 1424 accum A, int B) 1425 -- Runtime Function: unsigned accum __usashlusa3 (unsigned accum A, 1426 int B) 1427 -- Runtime Function: unsigned long accum __usashluda3 (unsigned long 1428 accum A, int B) 1429 -- Runtime Function: unsigned long long accum __usashluta3 (unsigned 1430 long long accum A, int B) 1431 These functions return the result of shifting A left by B bits 1432 with unsigned saturation. 1433 1434 4.4.2 Comparison functions 1435 -------------------------- 1436 1437 The following functions implement fixed-point comparisons. These 1438 functions implement a low-level compare, upon which the higher level 1439 comparison operators (such as less than and greater than or equal to) 1440 can be constructed. The returned values lie in the range zero to two, 1441 to allow the high-level operators to be implemented by testing the 1442 returned result using either signed or unsigned comparison. 1443 1444 -- Runtime Function: int __cmpqq2 (short fract A, short fract B) 1445 -- Runtime Function: int __cmphq2 (fract A, fract B) 1446 -- Runtime Function: int __cmpsq2 (long fract A, long fract B) 1447 -- Runtime Function: int __cmpdq2 (long long fract A, long long fract 1448 B) 1449 -- Runtime Function: int __cmpuqq2 (unsigned short fract A, unsigned 1450 short fract B) 1451 -- Runtime Function: int __cmpuhq2 (unsigned fract A, unsigned fract B) 1452 -- Runtime Function: int __cmpusq2 (unsigned long fract A, unsigned 1453 long fract B) 1454 -- Runtime Function: int __cmpudq2 (unsigned long long fract A, 1455 unsigned long long fract B) 1456 -- Runtime Function: int __cmpha2 (short accum A, short accum B) 1457 -- Runtime Function: int __cmpsa2 (accum A, accum B) 1458 -- Runtime Function: int __cmpda2 (long accum A, long accum B) 1459 -- Runtime Function: int __cmpta2 (long long accum A, long long accum 1460 B) 1461 -- Runtime Function: int __cmpuha2 (unsigned short accum A, unsigned 1462 short accum B) 1463 -- Runtime Function: int __cmpusa2 (unsigned accum A, unsigned accum B) 1464 -- Runtime Function: int __cmpuda2 (unsigned long accum A, unsigned 1465 long accum B) 1466 -- Runtime Function: int __cmputa2 (unsigned long long accum A, 1467 unsigned long long accum B) 1468 These functions perform a signed or unsigned comparison of A and B 1469 (depending on the selected machine mode). If A is less than B, 1470 they return 0; if A is greater than B, they return 2; and if A and 1471 B are equal they return 1. 1472 1473 4.4.3 Conversion functions 1474 -------------------------- 1475 1476 -- Runtime Function: fract __fractqqhq2 (short fract A) 1477 -- Runtime Function: long fract __fractqqsq2 (short fract A) 1478 -- Runtime Function: long long fract __fractqqdq2 (short fract A) 1479 -- Runtime Function: short accum __fractqqha (short fract A) 1480 -- Runtime Function: accum __fractqqsa (short fract A) 1481 -- Runtime Function: long accum __fractqqda (short fract A) 1482 -- Runtime Function: long long accum __fractqqta (short fract A) 1483 -- Runtime Function: unsigned short fract __fractqquqq (short fract A) 1484 -- Runtime Function: unsigned fract __fractqquhq (short fract A) 1485 -- Runtime Function: unsigned long fract __fractqqusq (short fract A) 1486 -- Runtime Function: unsigned long long fract __fractqqudq (short 1487 fract A) 1488 -- Runtime Function: unsigned short accum __fractqquha (short fract A) 1489 -- Runtime Function: unsigned accum __fractqqusa (short fract A) 1490 -- Runtime Function: unsigned long accum __fractqquda (short fract A) 1491 -- Runtime Function: unsigned long long accum __fractqquta (short 1492 fract A) 1493 -- Runtime Function: signed char __fractqqqi (short fract A) 1494 -- Runtime Function: short __fractqqhi (short fract A) 1495 -- Runtime Function: int __fractqqsi (short fract A) 1496 -- Runtime Function: long __fractqqdi (short fract A) 1497 -- Runtime Function: long long __fractqqti (short fract A) 1498 -- Runtime Function: float __fractqqsf (short fract A) 1499 -- Runtime Function: double __fractqqdf (short fract A) 1500 -- Runtime Function: short fract __fracthqqq2 (fract A) 1501 -- Runtime Function: long fract __fracthqsq2 (fract A) 1502 -- Runtime Function: long long fract __fracthqdq2 (fract A) 1503 -- Runtime Function: short accum __fracthqha (fract A) 1504 -- Runtime Function: accum __fracthqsa (fract A) 1505 -- Runtime Function: long accum __fracthqda (fract A) 1506 -- Runtime Function: long long accum __fracthqta (fract A) 1507 -- Runtime Function: unsigned short fract __fracthquqq (fract A) 1508 -- Runtime Function: unsigned fract __fracthquhq (fract A) 1509 -- Runtime Function: unsigned long fract __fracthqusq (fract A) 1510 -- Runtime Function: unsigned long long fract __fracthqudq (fract A) 1511 -- Runtime Function: unsigned short accum __fracthquha (fract A) 1512 -- Runtime Function: unsigned accum __fracthqusa (fract A) 1513 -- Runtime Function: unsigned long accum __fracthquda (fract A) 1514 -- Runtime Function: unsigned long long accum __fracthquta (fract A) 1515 -- Runtime Function: signed char __fracthqqi (fract A) 1516 -- Runtime Function: short __fracthqhi (fract A) 1517 -- Runtime Function: int __fracthqsi (fract A) 1518 -- Runtime Function: long __fracthqdi (fract A) 1519 -- Runtime Function: long long __fracthqti (fract A) 1520 -- Runtime Function: float __fracthqsf (fract A) 1521 -- Runtime Function: double __fracthqdf (fract A) 1522 -- Runtime Function: short fract __fractsqqq2 (long fract A) 1523 -- Runtime Function: fract __fractsqhq2 (long fract A) 1524 -- Runtime Function: long long fract __fractsqdq2 (long fract A) 1525 -- Runtime Function: short accum __fractsqha (long fract A) 1526 -- Runtime Function: accum __fractsqsa (long fract A) 1527 -- Runtime Function: long accum __fractsqda (long fract A) 1528 -- Runtime Function: long long accum __fractsqta (long fract A) 1529 -- Runtime Function: unsigned short fract __fractsquqq (long fract A) 1530 -- Runtime Function: unsigned fract __fractsquhq (long fract A) 1531 -- Runtime Function: unsigned long fract __fractsqusq (long fract A) 1532 -- Runtime Function: unsigned long long fract __fractsqudq (long fract 1533 A) 1534 -- Runtime Function: unsigned short accum __fractsquha (long fract A) 1535 -- Runtime Function: unsigned accum __fractsqusa (long fract A) 1536 -- Runtime Function: unsigned long accum __fractsquda (long fract A) 1537 -- Runtime Function: unsigned long long accum __fractsquta (long fract 1538 A) 1539 -- Runtime Function: signed char __fractsqqi (long fract A) 1540 -- Runtime Function: short __fractsqhi (long fract A) 1541 -- Runtime Function: int __fractsqsi (long fract A) 1542 -- Runtime Function: long __fractsqdi (long fract A) 1543 -- Runtime Function: long long __fractsqti (long fract A) 1544 -- Runtime Function: float __fractsqsf (long fract A) 1545 -- Runtime Function: double __fractsqdf (long fract A) 1546 -- Runtime Function: short fract __fractdqqq2 (long long fract A) 1547 -- Runtime Function: fract __fractdqhq2 (long long fract A) 1548 -- Runtime Function: long fract __fractdqsq2 (long long fract A) 1549 -- Runtime Function: short accum __fractdqha (long long fract A) 1550 -- Runtime Function: accum __fractdqsa (long long fract A) 1551 -- Runtime Function: long accum __fractdqda (long long fract A) 1552 -- Runtime Function: long long accum __fractdqta (long long fract A) 1553 -- Runtime Function: unsigned short fract __fractdquqq (long long 1554 fract A) 1555 -- Runtime Function: unsigned fract __fractdquhq (long long fract A) 1556 -- Runtime Function: unsigned long fract __fractdqusq (long long fract 1557 A) 1558 -- Runtime Function: unsigned long long fract __fractdqudq (long long 1559 fract A) 1560 -- Runtime Function: unsigned short accum __fractdquha (long long 1561 fract A) 1562 -- Runtime Function: unsigned accum __fractdqusa (long long fract A) 1563 -- Runtime Function: unsigned long accum __fractdquda (long long fract 1564 A) 1565 -- Runtime Function: unsigned long long accum __fractdquta (long long 1566 fract A) 1567 -- Runtime Function: signed char __fractdqqi (long long fract A) 1568 -- Runtime Function: short __fractdqhi (long long fract A) 1569 -- Runtime Function: int __fractdqsi (long long fract A) 1570 -- Runtime Function: long __fractdqdi (long long fract A) 1571 -- Runtime Function: long long __fractdqti (long long fract A) 1572 -- Runtime Function: float __fractdqsf (long long fract A) 1573 -- Runtime Function: double __fractdqdf (long long fract A) 1574 -- Runtime Function: short fract __fracthaqq (short accum A) 1575 -- Runtime Function: fract __fracthahq (short accum A) 1576 -- Runtime Function: long fract __fracthasq (short accum A) 1577 -- Runtime Function: long long fract __fracthadq (short accum A) 1578 -- Runtime Function: accum __fracthasa2 (short accum A) 1579 -- Runtime Function: long accum __fracthada2 (short accum A) 1580 -- Runtime Function: long long accum __fracthata2 (short accum A) 1581 -- Runtime Function: unsigned short fract __fracthauqq (short accum A) 1582 -- Runtime Function: unsigned fract __fracthauhq (short accum A) 1583 -- Runtime Function: unsigned long fract __fracthausq (short accum A) 1584 -- Runtime Function: unsigned long long fract __fracthaudq (short 1585 accum A) 1586 -- Runtime Function: unsigned short accum __fracthauha (short accum A) 1587 -- Runtime Function: unsigned accum __fracthausa (short accum A) 1588 -- Runtime Function: unsigned long accum __fracthauda (short accum A) 1589 -- Runtime Function: unsigned long long accum __fracthauta (short 1590 accum A) 1591 -- Runtime Function: signed char __fracthaqi (short accum A) 1592 -- Runtime Function: short __fracthahi (short accum A) 1593 -- Runtime Function: int __fracthasi (short accum A) 1594 -- Runtime Function: long __fracthadi (short accum A) 1595 -- Runtime Function: long long __fracthati (short accum A) 1596 -- Runtime Function: float __fracthasf (short accum A) 1597 -- Runtime Function: double __fracthadf (short accum A) 1598 -- Runtime Function: short fract __fractsaqq (accum A) 1599 -- Runtime Function: fract __fractsahq (accum A) 1600 -- Runtime Function: long fract __fractsasq (accum A) 1601 -- Runtime Function: long long fract __fractsadq (accum A) 1602 -- Runtime Function: short accum __fractsaha2 (accum A) 1603 -- Runtime Function: long accum __fractsada2 (accum A) 1604 -- Runtime Function: long long accum __fractsata2 (accum A) 1605 -- Runtime Function: unsigned short fract __fractsauqq (accum A) 1606 -- Runtime Function: unsigned fract __fractsauhq (accum A) 1607 -- Runtime Function: unsigned long fract __fractsausq (accum A) 1608 -- Runtime Function: unsigned long long fract __fractsaudq (accum A) 1609 -- Runtime Function: unsigned short accum __fractsauha (accum A) 1610 -- Runtime Function: unsigned accum __fractsausa (accum A) 1611 -- Runtime Function: unsigned long accum __fractsauda (accum A) 1612 -- Runtime Function: unsigned long long accum __fractsauta (accum A) 1613 -- Runtime Function: signed char __fractsaqi (accum A) 1614 -- Runtime Function: short __fractsahi (accum A) 1615 -- Runtime Function: int __fractsasi (accum A) 1616 -- Runtime Function: long __fractsadi (accum A) 1617 -- Runtime Function: long long __fractsati (accum A) 1618 -- Runtime Function: float __fractsasf (accum A) 1619 -- Runtime Function: double __fractsadf (accum A) 1620 -- Runtime Function: short fract __fractdaqq (long accum A) 1621 -- Runtime Function: fract __fractdahq (long accum A) 1622 -- Runtime Function: long fract __fractdasq (long accum A) 1623 -- Runtime Function: long long fract __fractdadq (long accum A) 1624 -- Runtime Function: short accum __fractdaha2 (long accum A) 1625 -- Runtime Function: accum __fractdasa2 (long accum A) 1626 -- Runtime Function: long long accum __fractdata2 (long accum A) 1627 -- Runtime Function: unsigned short fract __fractdauqq (long accum A) 1628 -- Runtime Function: unsigned fract __fractdauhq (long accum A) 1629 -- Runtime Function: unsigned long fract __fractdausq (long accum A) 1630 -- Runtime Function: unsigned long long fract __fractdaudq (long accum 1631 A) 1632 -- Runtime Function: unsigned short accum __fractdauha (long accum A) 1633 -- Runtime Function: unsigned accum __fractdausa (long accum A) 1634 -- Runtime Function: unsigned long accum __fractdauda (long accum A) 1635 -- Runtime Function: unsigned long long accum __fractdauta (long accum 1636 A) 1637 -- Runtime Function: signed char __fractdaqi (long accum A) 1638 -- Runtime Function: short __fractdahi (long accum A) 1639 -- Runtime Function: int __fractdasi (long accum A) 1640 -- Runtime Function: long __fractdadi (long accum A) 1641 -- Runtime Function: long long __fractdati (long accum A) 1642 -- Runtime Function: float __fractdasf (long accum A) 1643 -- Runtime Function: double __fractdadf (long accum A) 1644 -- Runtime Function: short fract __fracttaqq (long long accum A) 1645 -- Runtime Function: fract __fracttahq (long long accum A) 1646 -- Runtime Function: long fract __fracttasq (long long accum A) 1647 -- Runtime Function: long long fract __fracttadq (long long accum A) 1648 -- Runtime Function: short accum __fracttaha2 (long long accum A) 1649 -- Runtime Function: accum __fracttasa2 (long long accum A) 1650 -- Runtime Function: long accum __fracttada2 (long long accum A) 1651 -- Runtime Function: unsigned short fract __fracttauqq (long long 1652 accum A) 1653 -- Runtime Function: unsigned fract __fracttauhq (long long accum A) 1654 -- Runtime Function: unsigned long fract __fracttausq (long long accum 1655 A) 1656 -- Runtime Function: unsigned long long fract __fracttaudq (long long 1657 accum A) 1658 -- Runtime Function: unsigned short accum __fracttauha (long long 1659 accum A) 1660 -- Runtime Function: unsigned accum __fracttausa (long long accum A) 1661 -- Runtime Function: unsigned long accum __fracttauda (long long accum 1662 A) 1663 -- Runtime Function: unsigned long long accum __fracttauta (long long 1664 accum A) 1665 -- Runtime Function: signed char __fracttaqi (long long accum A) 1666 -- Runtime Function: short __fracttahi (long long accum A) 1667 -- Runtime Function: int __fracttasi (long long accum A) 1668 -- Runtime Function: long __fracttadi (long long accum A) 1669 -- Runtime Function: long long __fracttati (long long accum A) 1670 -- Runtime Function: float __fracttasf (long long accum A) 1671 -- Runtime Function: double __fracttadf (long long accum A) 1672 -- Runtime Function: short fract __fractuqqqq (unsigned short fract A) 1673 -- Runtime Function: fract __fractuqqhq (unsigned short fract A) 1674 -- Runtime Function: long fract __fractuqqsq (unsigned short fract A) 1675 -- Runtime Function: long long fract __fractuqqdq (unsigned short 1676 fract A) 1677 -- Runtime Function: short accum __fractuqqha (unsigned short fract A) 1678 -- Runtime Function: accum __fractuqqsa (unsigned short fract A) 1679 -- Runtime Function: long accum __fractuqqda (unsigned short fract A) 1680 -- Runtime Function: long long accum __fractuqqta (unsigned short 1681 fract A) 1682 -- Runtime Function: unsigned fract __fractuqquhq2 (unsigned short 1683 fract A) 1684 -- Runtime Function: unsigned long fract __fractuqqusq2 (unsigned 1685 short fract A) 1686 -- Runtime Function: unsigned long long fract __fractuqqudq2 (unsigned 1687 short fract A) 1688 -- Runtime Function: unsigned short accum __fractuqquha (unsigned 1689 short fract A) 1690 -- Runtime Function: unsigned accum __fractuqqusa (unsigned short 1691 fract A) 1692 -- Runtime Function: unsigned long accum __fractuqquda (unsigned short 1693 fract A) 1694 -- Runtime Function: unsigned long long accum __fractuqquta (unsigned 1695 short fract A) 1696 -- Runtime Function: signed char __fractuqqqi (unsigned short fract A) 1697 -- Runtime Function: short __fractuqqhi (unsigned short fract A) 1698 -- Runtime Function: int __fractuqqsi (unsigned short fract A) 1699 -- Runtime Function: long __fractuqqdi (unsigned short fract A) 1700 -- Runtime Function: long long __fractuqqti (unsigned short fract A) 1701 -- Runtime Function: float __fractuqqsf (unsigned short fract A) 1702 -- Runtime Function: double __fractuqqdf (unsigned short fract A) 1703 -- Runtime Function: short fract __fractuhqqq (unsigned fract A) 1704 -- Runtime Function: fract __fractuhqhq (unsigned fract A) 1705 -- Runtime Function: long fract __fractuhqsq (unsigned fract A) 1706 -- Runtime Function: long long fract __fractuhqdq (unsigned fract A) 1707 -- Runtime Function: short accum __fractuhqha (unsigned fract A) 1708 -- Runtime Function: accum __fractuhqsa (unsigned fract A) 1709 -- Runtime Function: long accum __fractuhqda (unsigned fract A) 1710 -- Runtime Function: long long accum __fractuhqta (unsigned fract A) 1711 -- Runtime Function: unsigned short fract __fractuhquqq2 (unsigned 1712 fract A) 1713 -- Runtime Function: unsigned long fract __fractuhqusq2 (unsigned 1714 fract A) 1715 -- Runtime Function: unsigned long long fract __fractuhqudq2 (unsigned 1716 fract A) 1717 -- Runtime Function: unsigned short accum __fractuhquha (unsigned 1718 fract A) 1719 -- Runtime Function: unsigned accum __fractuhqusa (unsigned fract A) 1720 -- Runtime Function: unsigned long accum __fractuhquda (unsigned fract 1721 A) 1722 -- Runtime Function: unsigned long long accum __fractuhquta (unsigned 1723 fract A) 1724 -- Runtime Function: signed char __fractuhqqi (unsigned fract A) 1725 -- Runtime Function: short __fractuhqhi (unsigned fract A) 1726 -- Runtime Function: int __fractuhqsi (unsigned fract A) 1727 -- Runtime Function: long __fractuhqdi (unsigned fract A) 1728 -- Runtime Function: long long __fractuhqti (unsigned fract A) 1729 -- Runtime Function: float __fractuhqsf (unsigned fract A) 1730 -- Runtime Function: double __fractuhqdf (unsigned fract A) 1731 -- Runtime Function: short fract __fractusqqq (unsigned long fract A) 1732 -- Runtime Function: fract __fractusqhq (unsigned long fract A) 1733 -- Runtime Function: long fract __fractusqsq (unsigned long fract A) 1734 -- Runtime Function: long long fract __fractusqdq (unsigned long fract 1735 A) 1736 -- Runtime Function: short accum __fractusqha (unsigned long fract A) 1737 -- Runtime Function: accum __fractusqsa (unsigned long fract A) 1738 -- Runtime Function: long accum __fractusqda (unsigned long fract A) 1739 -- Runtime Function: long long accum __fractusqta (unsigned long fract 1740 A) 1741 -- Runtime Function: unsigned short fract __fractusquqq2 (unsigned 1742 long fract A) 1743 -- Runtime Function: unsigned fract __fractusquhq2 (unsigned long 1744 fract A) 1745 -- Runtime Function: unsigned long long fract __fractusqudq2 (unsigned 1746 long fract A) 1747 -- Runtime Function: unsigned short accum __fractusquha (unsigned long 1748 fract A) 1749 -- Runtime Function: unsigned accum __fractusqusa (unsigned long fract 1750 A) 1751 -- Runtime Function: unsigned long accum __fractusquda (unsigned long 1752 fract A) 1753 -- Runtime Function: unsigned long long accum __fractusquta (unsigned 1754 long fract A) 1755 -- Runtime Function: signed char __fractusqqi (unsigned long fract A) 1756 -- Runtime Function: short __fractusqhi (unsigned long fract A) 1757 -- Runtime Function: int __fractusqsi (unsigned long fract A) 1758 -- Runtime Function: long __fractusqdi (unsigned long fract A) 1759 -- Runtime Function: long long __fractusqti (unsigned long fract A) 1760 -- Runtime Function: float __fractusqsf (unsigned long fract A) 1761 -- Runtime Function: double __fractusqdf (unsigned long fract A) 1762 -- Runtime Function: short fract __fractudqqq (unsigned long long 1763 fract A) 1764 -- Runtime Function: fract __fractudqhq (unsigned long long fract A) 1765 -- Runtime Function: long fract __fractudqsq (unsigned long long fract 1766 A) 1767 -- Runtime Function: long long fract __fractudqdq (unsigned long long 1768 fract A) 1769 -- Runtime Function: short accum __fractudqha (unsigned long long 1770 fract A) 1771 -- Runtime Function: accum __fractudqsa (unsigned long long fract A) 1772 -- Runtime Function: long accum __fractudqda (unsigned long long fract 1773 A) 1774 -- Runtime Function: long long accum __fractudqta (unsigned long long 1775 fract A) 1776 -- Runtime Function: unsigned short fract __fractudquqq2 (unsigned 1777 long long fract A) 1778 -- Runtime Function: unsigned fract __fractudquhq2 (unsigned long long 1779 fract A) 1780 -- Runtime Function: unsigned long fract __fractudqusq2 (unsigned long 1781 long fract A) 1782 -- Runtime Function: unsigned short accum __fractudquha (unsigned long 1783 long fract A) 1784 -- Runtime Function: unsigned accum __fractudqusa (unsigned long long 1785 fract A) 1786 -- Runtime Function: unsigned long accum __fractudquda (unsigned long 1787 long fract A) 1788 -- Runtime Function: unsigned long long accum __fractudquta (unsigned 1789 long long fract A) 1790 -- Runtime Function: signed char __fractudqqi (unsigned long long 1791 fract A) 1792 -- Runtime Function: short __fractudqhi (unsigned long long fract A) 1793 -- Runtime Function: int __fractudqsi (unsigned long long fract A) 1794 -- Runtime Function: long __fractudqdi (unsigned long long fract A) 1795 -- Runtime Function: long long __fractudqti (unsigned long long fract 1796 A) 1797 -- Runtime Function: float __fractudqsf (unsigned long long fract A) 1798 -- Runtime Function: double __fractudqdf (unsigned long long fract A) 1799 -- Runtime Function: short fract __fractuhaqq (unsigned short accum A) 1800 -- Runtime Function: fract __fractuhahq (unsigned short accum A) 1801 -- Runtime Function: long fract __fractuhasq (unsigned short accum A) 1802 -- Runtime Function: long long fract __fractuhadq (unsigned short 1803 accum A) 1804 -- Runtime Function: short accum __fractuhaha (unsigned short accum A) 1805 -- Runtime Function: accum __fractuhasa (unsigned short accum A) 1806 -- Runtime Function: long accum __fractuhada (unsigned short accum A) 1807 -- Runtime Function: long long accum __fractuhata (unsigned short 1808 accum A) 1809 -- Runtime Function: unsigned short fract __fractuhauqq (unsigned 1810 short accum A) 1811 -- Runtime Function: unsigned fract __fractuhauhq (unsigned short 1812 accum A) 1813 -- Runtime Function: unsigned long fract __fractuhausq (unsigned short 1814 accum A) 1815 -- Runtime Function: unsigned long long fract __fractuhaudq (unsigned 1816 short accum A) 1817 -- Runtime Function: unsigned accum __fractuhausa2 (unsigned short 1818 accum A) 1819 -- Runtime Function: unsigned long accum __fractuhauda2 (unsigned 1820 short accum A) 1821 -- Runtime Function: unsigned long long accum __fractuhauta2 (unsigned 1822 short accum A) 1823 -- Runtime Function: signed char __fractuhaqi (unsigned short accum A) 1824 -- Runtime Function: short __fractuhahi (unsigned short accum A) 1825 -- Runtime Function: int __fractuhasi (unsigned short accum A) 1826 -- Runtime Function: long __fractuhadi (unsigned short accum A) 1827 -- Runtime Function: long long __fractuhati (unsigned short accum A) 1828 -- Runtime Function: float __fractuhasf (unsigned short accum A) 1829 -- Runtime Function: double __fractuhadf (unsigned short accum A) 1830 -- Runtime Function: short fract __fractusaqq (unsigned accum A) 1831 -- Runtime Function: fract __fractusahq (unsigned accum A) 1832 -- Runtime Function: long fract __fractusasq (unsigned accum A) 1833 -- Runtime Function: long long fract __fractusadq (unsigned accum A) 1834 -- Runtime Function: short accum __fractusaha (unsigned accum A) 1835 -- Runtime Function: accum __fractusasa (unsigned accum A) 1836 -- Runtime Function: long accum __fractusada (unsigned accum A) 1837 -- Runtime Function: long long accum __fractusata (unsigned accum A) 1838 -- Runtime Function: unsigned short fract __fractusauqq (unsigned 1839 accum A) 1840 -- Runtime Function: unsigned fract __fractusauhq (unsigned accum A) 1841 -- Runtime Function: unsigned long fract __fractusausq (unsigned accum 1842 A) 1843 -- Runtime Function: unsigned long long fract __fractusaudq (unsigned 1844 accum A) 1845 -- Runtime Function: unsigned short accum __fractusauha2 (unsigned 1846 accum A) 1847 -- Runtime Function: unsigned long accum __fractusauda2 (unsigned 1848 accum A) 1849 -- Runtime Function: unsigned long long accum __fractusauta2 (unsigned 1850 accum A) 1851 -- Runtime Function: signed char __fractusaqi (unsigned accum A) 1852 -- Runtime Function: short __fractusahi (unsigned accum A) 1853 -- Runtime Function: int __fractusasi (unsigned accum A) 1854 -- Runtime Function: long __fractusadi (unsigned accum A) 1855 -- Runtime Function: long long __fractusati (unsigned accum A) 1856 -- Runtime Function: float __fractusasf (unsigned accum A) 1857 -- Runtime Function: double __fractusadf (unsigned accum A) 1858 -- Runtime Function: short fract __fractudaqq (unsigned long accum A) 1859 -- Runtime Function: fract __fractudahq (unsigned long accum A) 1860 -- Runtime Function: long fract __fractudasq (unsigned long accum A) 1861 -- Runtime Function: long long fract __fractudadq (unsigned long accum 1862 A) 1863 -- Runtime Function: short accum __fractudaha (unsigned long accum A) 1864 -- Runtime Function: accum __fractudasa (unsigned long accum A) 1865 -- Runtime Function: long accum __fractudada (unsigned long accum A) 1866 -- Runtime Function: long long accum __fractudata (unsigned long accum 1867 A) 1868 -- Runtime Function: unsigned short fract __fractudauqq (unsigned long 1869 accum A) 1870 -- Runtime Function: unsigned fract __fractudauhq (unsigned long accum 1871 A) 1872 -- Runtime Function: unsigned long fract __fractudausq (unsigned long 1873 accum A) 1874 -- Runtime Function: unsigned long long fract __fractudaudq (unsigned 1875 long accum A) 1876 -- Runtime Function: unsigned short accum __fractudauha2 (unsigned 1877 long accum A) 1878 -- Runtime Function: unsigned accum __fractudausa2 (unsigned long 1879 accum A) 1880 -- Runtime Function: unsigned long long accum __fractudauta2 (unsigned 1881 long accum A) 1882 -- Runtime Function: signed char __fractudaqi (unsigned long accum A) 1883 -- Runtime Function: short __fractudahi (unsigned long accum A) 1884 -- Runtime Function: int __fractudasi (unsigned long accum A) 1885 -- Runtime Function: long __fractudadi (unsigned long accum A) 1886 -- Runtime Function: long long __fractudati (unsigned long accum A) 1887 -- Runtime Function: float __fractudasf (unsigned long accum A) 1888 -- Runtime Function: double __fractudadf (unsigned long accum A) 1889 -- Runtime Function: short fract __fractutaqq (unsigned long long 1890 accum A) 1891 -- Runtime Function: fract __fractutahq (unsigned long long accum A) 1892 -- Runtime Function: long fract __fractutasq (unsigned long long accum 1893 A) 1894 -- Runtime Function: long long fract __fractutadq (unsigned long long 1895 accum A) 1896 -- Runtime Function: short accum __fractutaha (unsigned long long 1897 accum A) 1898 -- Runtime Function: accum __fractutasa (unsigned long long accum A) 1899 -- Runtime Function: long accum __fractutada (unsigned long long accum 1900 A) 1901 -- Runtime Function: long long accum __fractutata (unsigned long long 1902 accum A) 1903 -- Runtime Function: unsigned short fract __fractutauqq (unsigned long 1904 long accum A) 1905 -- Runtime Function: unsigned fract __fractutauhq (unsigned long long 1906 accum A) 1907 -- Runtime Function: unsigned long fract __fractutausq (unsigned long 1908 long accum A) 1909 -- Runtime Function: unsigned long long fract __fractutaudq (unsigned 1910 long long accum A) 1911 -- Runtime Function: unsigned short accum __fractutauha2 (unsigned 1912 long long accum A) 1913 -- Runtime Function: unsigned accum __fractutausa2 (unsigned long long 1914 accum A) 1915 -- Runtime Function: unsigned long accum __fractutauda2 (unsigned long 1916 long accum A) 1917 -- Runtime Function: signed char __fractutaqi (unsigned long long 1918 accum A) 1919 -- Runtime Function: short __fractutahi (unsigned long long accum A) 1920 -- Runtime Function: int __fractutasi (unsigned long long accum A) 1921 -- Runtime Function: long __fractutadi (unsigned long long accum A) 1922 -- Runtime Function: long long __fractutati (unsigned long long accum 1923 A) 1924 -- Runtime Function: float __fractutasf (unsigned long long accum A) 1925 -- Runtime Function: double __fractutadf (unsigned long long accum A) 1926 -- Runtime Function: short fract __fractqiqq (signed char A) 1927 -- Runtime Function: fract __fractqihq (signed char A) 1928 -- Runtime Function: long fract __fractqisq (signed char A) 1929 -- Runtime Function: long long fract __fractqidq (signed char A) 1930 -- Runtime Function: short accum __fractqiha (signed char A) 1931 -- Runtime Function: accum __fractqisa (signed char A) 1932 -- Runtime Function: long accum __fractqida (signed char A) 1933 -- Runtime Function: long long accum __fractqita (signed char A) 1934 -- Runtime Function: unsigned short fract __fractqiuqq (signed char A) 1935 -- Runtime Function: unsigned fract __fractqiuhq (signed char A) 1936 -- Runtime Function: unsigned long fract __fractqiusq (signed char A) 1937 -- Runtime Function: unsigned long long fract __fractqiudq (signed 1938 char A) 1939 -- Runtime Function: unsigned short accum __fractqiuha (signed char A) 1940 -- Runtime Function: unsigned accum __fractqiusa (signed char A) 1941 -- Runtime Function: unsigned long accum __fractqiuda (signed char A) 1942 -- Runtime Function: unsigned long long accum __fractqiuta (signed 1943 char A) 1944 -- Runtime Function: short fract __fracthiqq (short A) 1945 -- Runtime Function: fract __fracthihq (short A) 1946 -- Runtime Function: long fract __fracthisq (short A) 1947 -- Runtime Function: long long fract __fracthidq (short A) 1948 -- Runtime Function: short accum __fracthiha (short A) 1949 -- Runtime Function: accum __fracthisa (short A) 1950 -- Runtime Function: long accum __fracthida (short A) 1951 -- Runtime Function: long long accum __fracthita (short A) 1952 -- Runtime Function: unsigned short fract __fracthiuqq (short A) 1953 -- Runtime Function: unsigned fract __fracthiuhq (short A) 1954 -- Runtime Function: unsigned long fract __fracthiusq (short A) 1955 -- Runtime Function: unsigned long long fract __fracthiudq (short A) 1956 -- Runtime Function: unsigned short accum __fracthiuha (short A) 1957 -- Runtime Function: unsigned accum __fracthiusa (short A) 1958 -- Runtime Function: unsigned long accum __fracthiuda (short A) 1959 -- Runtime Function: unsigned long long accum __fracthiuta (short A) 1960 -- Runtime Function: short fract __fractsiqq (int A) 1961 -- Runtime Function: fract __fractsihq (int A) 1962 -- Runtime Function: long fract __fractsisq (int A) 1963 -- Runtime Function: long long fract __fractsidq (int A) 1964 -- Runtime Function: short accum __fractsiha (int A) 1965 -- Runtime Function: accum __fractsisa (int A) 1966 -- Runtime Function: long accum __fractsida (int A) 1967 -- Runtime Function: long long accum __fractsita (int A) 1968 -- Runtime Function: unsigned short fract __fractsiuqq (int A) 1969 -- Runtime Function: unsigned fract __fractsiuhq (int A) 1970 -- Runtime Function: unsigned long fract __fractsiusq (int A) 1971 -- Runtime Function: unsigned long long fract __fractsiudq (int A) 1972 -- Runtime Function: unsigned short accum __fractsiuha (int A) 1973 -- Runtime Function: unsigned accum __fractsiusa (int A) 1974 -- Runtime Function: unsigned long accum __fractsiuda (int A) 1975 -- Runtime Function: unsigned long long accum __fractsiuta (int A) 1976 -- Runtime Function: short fract __fractdiqq (long A) 1977 -- Runtime Function: fract __fractdihq (long A) 1978 -- Runtime Function: long fract __fractdisq (long A) 1979 -- Runtime Function: long long fract __fractdidq (long A) 1980 -- Runtime Function: short accum __fractdiha (long A) 1981 -- Runtime Function: accum __fractdisa (long A) 1982 -- Runtime Function: long accum __fractdida (long A) 1983 -- Runtime Function: long long accum __fractdita (long A) 1984 -- Runtime Function: unsigned short fract __fractdiuqq (long A) 1985 -- Runtime Function: unsigned fract __fractdiuhq (long A) 1986 -- Runtime Function: unsigned long fract __fractdiusq (long A) 1987 -- Runtime Function: unsigned long long fract __fractdiudq (long A) 1988 -- Runtime Function: unsigned short accum __fractdiuha (long A) 1989 -- Runtime Function: unsigned accum __fractdiusa (long A) 1990 -- Runtime Function: unsigned long accum __fractdiuda (long A) 1991 -- Runtime Function: unsigned long long accum __fractdiuta (long A) 1992 -- Runtime Function: short fract __fracttiqq (long long A) 1993 -- Runtime Function: fract __fracttihq (long long A) 1994 -- Runtime Function: long fract __fracttisq (long long A) 1995 -- Runtime Function: long long fract __fracttidq (long long A) 1996 -- Runtime Function: short accum __fracttiha (long long A) 1997 -- Runtime Function: accum __fracttisa (long long A) 1998 -- Runtime Function: long accum __fracttida (long long A) 1999 -- Runtime Function: long long accum __fracttita (long long A) 2000 -- Runtime Function: unsigned short fract __fracttiuqq (long long A) 2001 -- Runtime Function: unsigned fract __fracttiuhq (long long A) 2002 -- Runtime Function: unsigned long fract __fracttiusq (long long A) 2003 -- Runtime Function: unsigned long long fract __fracttiudq (long long 2004 A) 2005 -- Runtime Function: unsigned short accum __fracttiuha (long long A) 2006 -- Runtime Function: unsigned accum __fracttiusa (long long A) 2007 -- Runtime Function: unsigned long accum __fracttiuda (long long A) 2008 -- Runtime Function: unsigned long long accum __fracttiuta (long long 2009 A) 2010 -- Runtime Function: short fract __fractsfqq (float A) 2011 -- Runtime Function: fract __fractsfhq (float A) 2012 -- Runtime Function: long fract __fractsfsq (float A) 2013 -- Runtime Function: long long fract __fractsfdq (float A) 2014 -- Runtime Function: short accum __fractsfha (float A) 2015 -- Runtime Function: accum __fractsfsa (float A) 2016 -- Runtime Function: long accum __fractsfda (float A) 2017 -- Runtime Function: long long accum __fractsfta (float A) 2018 -- Runtime Function: unsigned short fract __fractsfuqq (float A) 2019 -- Runtime Function: unsigned fract __fractsfuhq (float A) 2020 -- Runtime Function: unsigned long fract __fractsfusq (float A) 2021 -- Runtime Function: unsigned long long fract __fractsfudq (float A) 2022 -- Runtime Function: unsigned short accum __fractsfuha (float A) 2023 -- Runtime Function: unsigned accum __fractsfusa (float A) 2024 -- Runtime Function: unsigned long accum __fractsfuda (float A) 2025 -- Runtime Function: unsigned long long accum __fractsfuta (float A) 2026 -- Runtime Function: short fract __fractdfqq (double A) 2027 -- Runtime Function: fract __fractdfhq (double A) 2028 -- Runtime Function: long fract __fractdfsq (double A) 2029 -- Runtime Function: long long fract __fractdfdq (double A) 2030 -- Runtime Function: short accum __fractdfha (double A) 2031 -- Runtime Function: accum __fractdfsa (double A) 2032 -- Runtime Function: long accum __fractdfda (double A) 2033 -- Runtime Function: long long accum __fractdfta (double A) 2034 -- Runtime Function: unsigned short fract __fractdfuqq (double A) 2035 -- Runtime Function: unsigned fract __fractdfuhq (double A) 2036 -- Runtime Function: unsigned long fract __fractdfusq (double A) 2037 -- Runtime Function: unsigned long long fract __fractdfudq (double A) 2038 -- Runtime Function: unsigned short accum __fractdfuha (double A) 2039 -- Runtime Function: unsigned accum __fractdfusa (double A) 2040 -- Runtime Function: unsigned long accum __fractdfuda (double A) 2041 -- Runtime Function: unsigned long long accum __fractdfuta (double A) 2042 These functions convert from fractional and signed non-fractionals 2043 to fractionals and signed non-fractionals, without saturation. 2044 2045 -- Runtime Function: fract __satfractqqhq2 (short fract A) 2046 -- Runtime Function: long fract __satfractqqsq2 (short fract A) 2047 -- Runtime Function: long long fract __satfractqqdq2 (short fract A) 2048 -- Runtime Function: short accum __satfractqqha (short fract A) 2049 -- Runtime Function: accum __satfractqqsa (short fract A) 2050 -- Runtime Function: long accum __satfractqqda (short fract A) 2051 -- Runtime Function: long long accum __satfractqqta (short fract A) 2052 -- Runtime Function: unsigned short fract __satfractqquqq (short fract 2053 A) 2054 -- Runtime Function: unsigned fract __satfractqquhq (short fract A) 2055 -- Runtime Function: unsigned long fract __satfractqqusq (short fract 2056 A) 2057 -- Runtime Function: unsigned long long fract __satfractqqudq (short 2058 fract A) 2059 -- Runtime Function: unsigned short accum __satfractqquha (short fract 2060 A) 2061 -- Runtime Function: unsigned accum __satfractqqusa (short fract A) 2062 -- Runtime Function: unsigned long accum __satfractqquda (short fract 2063 A) 2064 -- Runtime Function: unsigned long long accum __satfractqquta (short 2065 fract A) 2066 -- Runtime Function: short fract __satfracthqqq2 (fract A) 2067 -- Runtime Function: long fract __satfracthqsq2 (fract A) 2068 -- Runtime Function: long long fract __satfracthqdq2 (fract A) 2069 -- Runtime Function: short accum __satfracthqha (fract A) 2070 -- Runtime Function: accum __satfracthqsa (fract A) 2071 -- Runtime Function: long accum __satfracthqda (fract A) 2072 -- Runtime Function: long long accum __satfracthqta (fract A) 2073 -- Runtime Function: unsigned short fract __satfracthquqq (fract A) 2074 -- Runtime Function: unsigned fract __satfracthquhq (fract A) 2075 -- Runtime Function: unsigned long fract __satfracthqusq (fract A) 2076 -- Runtime Function: unsigned long long fract __satfracthqudq (fract A) 2077 -- Runtime Function: unsigned short accum __satfracthquha (fract A) 2078 -- Runtime Function: unsigned accum __satfracthqusa (fract A) 2079 -- Runtime Function: unsigned long accum __satfracthquda (fract A) 2080 -- Runtime Function: unsigned long long accum __satfracthquta (fract A) 2081 -- Runtime Function: short fract __satfractsqqq2 (long fract A) 2082 -- Runtime Function: fract __satfractsqhq2 (long fract A) 2083 -- Runtime Function: long long fract __satfractsqdq2 (long fract A) 2084 -- Runtime Function: short accum __satfractsqha (long fract A) 2085 -- Runtime Function: accum __satfractsqsa (long fract A) 2086 -- Runtime Function: long accum __satfractsqda (long fract A) 2087 -- Runtime Function: long long accum __satfractsqta (long fract A) 2088 -- Runtime Function: unsigned short fract __satfractsquqq (long fract 2089 A) 2090 -- Runtime Function: unsigned fract __satfractsquhq (long fract A) 2091 -- Runtime Function: unsigned long fract __satfractsqusq (long fract A) 2092 -- Runtime Function: unsigned long long fract __satfractsqudq (long 2093 fract A) 2094 -- Runtime Function: unsigned short accum __satfractsquha (long fract 2095 A) 2096 -- Runtime Function: unsigned accum __satfractsqusa (long fract A) 2097 -- Runtime Function: unsigned long accum __satfractsquda (long fract A) 2098 -- Runtime Function: unsigned long long accum __satfractsquta (long 2099 fract A) 2100 -- Runtime Function: short fract __satfractdqqq2 (long long fract A) 2101 -- Runtime Function: fract __satfractdqhq2 (long long fract A) 2102 -- Runtime Function: long fract __satfractdqsq2 (long long fract A) 2103 -- Runtime Function: short accum __satfractdqha (long long fract A) 2104 -- Runtime Function: accum __satfractdqsa (long long fract A) 2105 -- Runtime Function: long accum __satfractdqda (long long fract A) 2106 -- Runtime Function: long long accum __satfractdqta (long long fract A) 2107 -- Runtime Function: unsigned short fract __satfractdquqq (long long 2108 fract A) 2109 -- Runtime Function: unsigned fract __satfractdquhq (long long fract A) 2110 -- Runtime Function: unsigned long fract __satfractdqusq (long long 2111 fract A) 2112 -- Runtime Function: unsigned long long fract __satfractdqudq (long 2113 long fract A) 2114 -- Runtime Function: unsigned short accum __satfractdquha (long long 2115 fract A) 2116 -- Runtime Function: unsigned accum __satfractdqusa (long long fract A) 2117 -- Runtime Function: unsigned long accum __satfractdquda (long long 2118 fract A) 2119 -- Runtime Function: unsigned long long accum __satfractdquta (long 2120 long fract A) 2121 -- Runtime Function: short fract __satfracthaqq (short accum A) 2122 -- Runtime Function: fract __satfracthahq (short accum A) 2123 -- Runtime Function: long fract __satfracthasq (short accum A) 2124 -- Runtime Function: long long fract __satfracthadq (short accum A) 2125 -- Runtime Function: accum __satfracthasa2 (short accum A) 2126 -- Runtime Function: long accum __satfracthada2 (short accum A) 2127 -- Runtime Function: long long accum __satfracthata2 (short accum A) 2128 -- Runtime Function: unsigned short fract __satfracthauqq (short accum 2129 A) 2130 -- Runtime Function: unsigned fract __satfracthauhq (short accum A) 2131 -- Runtime Function: unsigned long fract __satfracthausq (short accum 2132 A) 2133 -- Runtime Function: unsigned long long fract __satfracthaudq (short 2134 accum A) 2135 -- Runtime Function: unsigned short accum __satfracthauha (short accum 2136 A) 2137 -- Runtime Function: unsigned accum __satfracthausa (short accum A) 2138 -- Runtime Function: unsigned long accum __satfracthauda (short accum 2139 A) 2140 -- Runtime Function: unsigned long long accum __satfracthauta (short 2141 accum A) 2142 -- Runtime Function: short fract __satfractsaqq (accum A) 2143 -- Runtime Function: fract __satfractsahq (accum A) 2144 -- Runtime Function: long fract __satfractsasq (accum A) 2145 -- Runtime Function: long long fract __satfractsadq (accum A) 2146 -- Runtime Function: short accum __satfractsaha2 (accum A) 2147 -- Runtime Function: long accum __satfractsada2 (accum A) 2148 -- Runtime Function: long long accum __satfractsata2 (accum A) 2149 -- Runtime Function: unsigned short fract __satfractsauqq (accum A) 2150 -- Runtime Function: unsigned fract __satfractsauhq (accum A) 2151 -- Runtime Function: unsigned long fract __satfractsausq (accum A) 2152 -- Runtime Function: unsigned long long fract __satfractsaudq (accum A) 2153 -- Runtime Function: unsigned short accum __satfractsauha (accum A) 2154 -- Runtime Function: unsigned accum __satfractsausa (accum A) 2155 -- Runtime Function: unsigned long accum __satfractsauda (accum A) 2156 -- Runtime Function: unsigned long long accum __satfractsauta (accum A) 2157 -- Runtime Function: short fract __satfractdaqq (long accum A) 2158 -- Runtime Function: fract __satfractdahq (long accum A) 2159 -- Runtime Function: long fract __satfractdasq (long accum A) 2160 -- Runtime Function: long long fract __satfractdadq (long accum A) 2161 -- Runtime Function: short accum __satfractdaha2 (long accum A) 2162 -- Runtime Function: accum __satfractdasa2 (long accum A) 2163 -- Runtime Function: long long accum __satfractdata2 (long accum A) 2164 -- Runtime Function: unsigned short fract __satfractdauqq (long accum 2165 A) 2166 -- Runtime Function: unsigned fract __satfractdauhq (long accum A) 2167 -- Runtime Function: unsigned long fract __satfractdausq (long accum A) 2168 -- Runtime Function: unsigned long long fract __satfractdaudq (long 2169 accum A) 2170 -- Runtime Function: unsigned short accum __satfractdauha (long accum 2171 A) 2172 -- Runtime Function: unsigned accum __satfractdausa (long accum A) 2173 -- Runtime Function: unsigned long accum __satfractdauda (long accum A) 2174 -- Runtime Function: unsigned long long accum __satfractdauta (long 2175 accum A) 2176 -- Runtime Function: short fract __satfracttaqq (long long accum A) 2177 -- Runtime Function: fract __satfracttahq (long long accum A) 2178 -- Runtime Function: long fract __satfracttasq (long long accum A) 2179 -- Runtime Function: long long fract __satfracttadq (long long accum A) 2180 -- Runtime Function: short accum __satfracttaha2 (long long accum A) 2181 -- Runtime Function: accum __satfracttasa2 (long long accum A) 2182 -- Runtime Function: long accum __satfracttada2 (long long accum A) 2183 -- Runtime Function: unsigned short fract __satfracttauqq (long long 2184 accum A) 2185 -- Runtime Function: unsigned fract __satfracttauhq (long long accum A) 2186 -- Runtime Function: unsigned long fract __satfracttausq (long long 2187 accum A) 2188 -- Runtime Function: unsigned long long fract __satfracttaudq (long 2189 long accum A) 2190 -- Runtime Function: unsigned short accum __satfracttauha (long long 2191 accum A) 2192 -- Runtime Function: unsigned accum __satfracttausa (long long accum A) 2193 -- Runtime Function: unsigned long accum __satfracttauda (long long 2194 accum A) 2195 -- Runtime Function: unsigned long long accum __satfracttauta (long 2196 long accum A) 2197 -- Runtime Function: short fract __satfractuqqqq (unsigned short fract 2198 A) 2199 -- Runtime Function: fract __satfractuqqhq (unsigned short fract A) 2200 -- Runtime Function: long fract __satfractuqqsq (unsigned short fract 2201 A) 2202 -- Runtime Function: long long fract __satfractuqqdq (unsigned short 2203 fract A) 2204 -- Runtime Function: short accum __satfractuqqha (unsigned short fract 2205 A) 2206 -- Runtime Function: accum __satfractuqqsa (unsigned short fract A) 2207 -- Runtime Function: long accum __satfractuqqda (unsigned short fract 2208 A) 2209 -- Runtime Function: long long accum __satfractuqqta (unsigned short 2210 fract A) 2211 -- Runtime Function: unsigned fract __satfractuqquhq2 (unsigned short 2212 fract A) 2213 -- Runtime Function: unsigned long fract __satfractuqqusq2 (unsigned 2214 short fract A) 2215 -- Runtime Function: unsigned long long fract __satfractuqqudq2 2216 (unsigned short fract A) 2217 -- Runtime Function: unsigned short accum __satfractuqquha (unsigned 2218 short fract A) 2219 -- Runtime Function: unsigned accum __satfractuqqusa (unsigned short 2220 fract A) 2221 -- Runtime Function: unsigned long accum __satfractuqquda (unsigned 2222 short fract A) 2223 -- Runtime Function: unsigned long long accum __satfractuqquta 2224 (unsigned short fract A) 2225 -- Runtime Function: short fract __satfractuhqqq (unsigned fract A) 2226 -- Runtime Function: fract __satfractuhqhq (unsigned fract A) 2227 -- Runtime Function: long fract __satfractuhqsq (unsigned fract A) 2228 -- Runtime Function: long long fract __satfractuhqdq (unsigned fract A) 2229 -- Runtime Function: short accum __satfractuhqha (unsigned fract A) 2230 -- Runtime Function: accum __satfractuhqsa (unsigned fract A) 2231 -- Runtime Function: long accum __satfractuhqda (unsigned fract A) 2232 -- Runtime Function: long long accum __satfractuhqta (unsigned fract A) 2233 -- Runtime Function: unsigned short fract __satfractuhquqq2 (unsigned 2234 fract A) 2235 -- Runtime Function: unsigned long fract __satfractuhqusq2 (unsigned 2236 fract A) 2237 -- Runtime Function: unsigned long long fract __satfractuhqudq2 2238 (unsigned fract A) 2239 -- Runtime Function: unsigned short accum __satfractuhquha (unsigned 2240 fract A) 2241 -- Runtime Function: unsigned accum __satfractuhqusa (unsigned fract A) 2242 -- Runtime Function: unsigned long accum __satfractuhquda (unsigned 2243 fract A) 2244 -- Runtime Function: unsigned long long accum __satfractuhquta 2245 (unsigned fract A) 2246 -- Runtime Function: short fract __satfractusqqq (unsigned long fract 2247 A) 2248 -- Runtime Function: fract __satfractusqhq (unsigned long fract A) 2249 -- Runtime Function: long fract __satfractusqsq (unsigned long fract A) 2250 -- Runtime Function: long long fract __satfractusqdq (unsigned long 2251 fract A) 2252 -- Runtime Function: short accum __satfractusqha (unsigned long fract 2253 A) 2254 -- Runtime Function: accum __satfractusqsa (unsigned long fract A) 2255 -- Runtime Function: long accum __satfractusqda (unsigned long fract A) 2256 -- Runtime Function: long long accum __satfractusqta (unsigned long 2257 fract A) 2258 -- Runtime Function: unsigned short fract __satfractusquqq2 (unsigned 2259 long fract A) 2260 -- Runtime Function: unsigned fract __satfractusquhq2 (unsigned long 2261 fract A) 2262 -- Runtime Function: unsigned long long fract __satfractusqudq2 2263 (unsigned long fract A) 2264 -- Runtime Function: unsigned short accum __satfractusquha (unsigned 2265 long fract A) 2266 -- Runtime Function: unsigned accum __satfractusqusa (unsigned long 2267 fract A) 2268 -- Runtime Function: unsigned long accum __satfractusquda (unsigned 2269 long fract A) 2270 -- Runtime Function: unsigned long long accum __satfractusquta 2271 (unsigned long fract A) 2272 -- Runtime Function: short fract __satfractudqqq (unsigned long long 2273 fract A) 2274 -- Runtime Function: fract __satfractudqhq (unsigned long long fract A) 2275 -- Runtime Function: long fract __satfractudqsq (unsigned long long 2276 fract A) 2277 -- Runtime Function: long long fract __satfractudqdq (unsigned long 2278 long fract A) 2279 -- Runtime Function: short accum __satfractudqha (unsigned long long 2280 fract A) 2281 -- Runtime Function: accum __satfractudqsa (unsigned long long fract A) 2282 -- Runtime Function: long accum __satfractudqda (unsigned long long 2283 fract A) 2284 -- Runtime Function: long long accum __satfractudqta (unsigned long 2285 long fract A) 2286 -- Runtime Function: unsigned short fract __satfractudquqq2 (unsigned 2287 long long fract A) 2288 -- Runtime Function: unsigned fract __satfractudquhq2 (unsigned long 2289 long fract A) 2290 -- Runtime Function: unsigned long fract __satfractudqusq2 (unsigned 2291 long long fract A) 2292 -- Runtime Function: unsigned short accum __satfractudquha (unsigned 2293 long long fract A) 2294 -- Runtime Function: unsigned accum __satfractudqusa (unsigned long 2295 long fract A) 2296 -- Runtime Function: unsigned long accum __satfractudquda (unsigned 2297 long long fract A) 2298 -- Runtime Function: unsigned long long accum __satfractudquta 2299 (unsigned long long fract A) 2300 -- Runtime Function: short fract __satfractuhaqq (unsigned short accum 2301 A) 2302 -- Runtime Function: fract __satfractuhahq (unsigned short accum A) 2303 -- Runtime Function: long fract __satfractuhasq (unsigned short accum 2304 A) 2305 -- Runtime Function: long long fract __satfractuhadq (unsigned short 2306 accum A) 2307 -- Runtime Function: short accum __satfractuhaha (unsigned short accum 2308 A) 2309 -- Runtime Function: accum __satfractuhasa (unsigned short accum A) 2310 -- Runtime Function: long accum __satfractuhada (unsigned short accum 2311 A) 2312 -- Runtime Function: long long accum __satfractuhata (unsigned short 2313 accum A) 2314 -- Runtime Function: unsigned short fract __satfractuhauqq (unsigned 2315 short accum A) 2316 -- Runtime Function: unsigned fract __satfractuhauhq (unsigned short 2317 accum A) 2318 -- Runtime Function: unsigned long fract __satfractuhausq (unsigned 2319 short accum A) 2320 -- Runtime Function: unsigned long long fract __satfractuhaudq 2321 (unsigned short accum A) 2322 -- Runtime Function: unsigned accum __satfractuhausa2 (unsigned short 2323 accum A) 2324 -- Runtime Function: unsigned long accum __satfractuhauda2 (unsigned 2325 short accum A) 2326 -- Runtime Function: unsigned long long accum __satfractuhauta2 2327 (unsigned short accum A) 2328 -- Runtime Function: short fract __satfractusaqq (unsigned accum A) 2329 -- Runtime Function: fract __satfractusahq (unsigned accum A) 2330 -- Runtime Function: long fract __satfractusasq (unsigned accum A) 2331 -- Runtime Function: long long fract __satfractusadq (unsigned accum A) 2332 -- Runtime Function: short accum __satfractusaha (unsigned accum A) 2333 -- Runtime Function: accum __satfractusasa (unsigned accum A) 2334 -- Runtime Function: long accum __satfractusada (unsigned accum A) 2335 -- Runtime Function: long long accum __satfractusata (unsigned accum A) 2336 -- Runtime Function: unsigned short fract __satfractusauqq (unsigned 2337 accum A) 2338 -- Runtime Function: unsigned fract __satfractusauhq (unsigned accum A) 2339 -- Runtime Function: unsigned long fract __satfractusausq (unsigned 2340 accum A) 2341 -- Runtime Function: unsigned long long fract __satfractusaudq 2342 (unsigned accum A) 2343 -- Runtime Function: unsigned short accum __satfractusauha2 (unsigned 2344 accum A) 2345 -- Runtime Function: unsigned long accum __satfractusauda2 (unsigned 2346 accum A) 2347 -- Runtime Function: unsigned long long accum __satfractusauta2 2348 (unsigned accum A) 2349 -- Runtime Function: short fract __satfractudaqq (unsigned long accum 2350 A) 2351 -- Runtime Function: fract __satfractudahq (unsigned long accum A) 2352 -- Runtime Function: long fract __satfractudasq (unsigned long accum A) 2353 -- Runtime Function: long long fract __satfractudadq (unsigned long 2354 accum A) 2355 -- Runtime Function: short accum __satfractudaha (unsigned long accum 2356 A) 2357 -- Runtime Function: accum __satfractudasa (unsigned long accum A) 2358 -- Runtime Function: long accum __satfractudada (unsigned long accum A) 2359 -- Runtime Function: long long accum __satfractudata (unsigned long 2360 accum A) 2361 -- Runtime Function: unsigned short fract __satfractudauqq (unsigned 2362 long accum A) 2363 -- Runtime Function: unsigned fract __satfractudauhq (unsigned long 2364 accum A) 2365 -- Runtime Function: unsigned long fract __satfractudausq (unsigned 2366 long accum A) 2367 -- Runtime Function: unsigned long long fract __satfractudaudq 2368 (unsigned long accum A) 2369 -- Runtime Function: unsigned short accum __satfractudauha2 (unsigned 2370 long accum A) 2371 -- Runtime Function: unsigned accum __satfractudausa2 (unsigned long 2372 accum A) 2373 -- Runtime Function: unsigned long long accum __satfractudauta2 2374 (unsigned long accum A) 2375 -- Runtime Function: short fract __satfractutaqq (unsigned long long 2376 accum A) 2377 -- Runtime Function: fract __satfractutahq (unsigned long long accum A) 2378 -- Runtime Function: long fract __satfractutasq (unsigned long long 2379 accum A) 2380 -- Runtime Function: long long fract __satfractutadq (unsigned long 2381 long accum A) 2382 -- Runtime Function: short accum __satfractutaha (unsigned long long 2383 accum A) 2384 -- Runtime Function: accum __satfractutasa (unsigned long long accum A) 2385 -- Runtime Function: long accum __satfractutada (unsigned long long 2386 accum A) 2387 -- Runtime Function: long long accum __satfractutata (unsigned long 2388 long accum A) 2389 -- Runtime Function: unsigned short fract __satfractutauqq (unsigned 2390 long long accum A) 2391 -- Runtime Function: unsigned fract __satfractutauhq (unsigned long 2392 long accum A) 2393 -- Runtime Function: unsigned long fract __satfractutausq (unsigned 2394 long long accum A) 2395 -- Runtime Function: unsigned long long fract __satfractutaudq 2396 (unsigned long long accum A) 2397 -- Runtime Function: unsigned short accum __satfractutauha2 (unsigned 2398 long long accum A) 2399 -- Runtime Function: unsigned accum __satfractutausa2 (unsigned long 2400 long accum A) 2401 -- Runtime Function: unsigned long accum __satfractutauda2 (unsigned 2402 long long accum A) 2403 -- Runtime Function: short fract __satfractqiqq (signed char A) 2404 -- Runtime Function: fract __satfractqihq (signed char A) 2405 -- Runtime Function: long fract __satfractqisq (signed char A) 2406 -- Runtime Function: long long fract __satfractqidq (signed char A) 2407 -- Runtime Function: short accum __satfractqiha (signed char A) 2408 -- Runtime Function: accum __satfractqisa (signed char A) 2409 -- Runtime Function: long accum __satfractqida (signed char A) 2410 -- Runtime Function: long long accum __satfractqita (signed char A) 2411 -- Runtime Function: unsigned short fract __satfractqiuqq (signed char 2412 A) 2413 -- Runtime Function: unsigned fract __satfractqiuhq (signed char A) 2414 -- Runtime Function: unsigned long fract __satfractqiusq (signed char 2415 A) 2416 -- Runtime Function: unsigned long long fract __satfractqiudq (signed 2417 char A) 2418 -- Runtime Function: unsigned short accum __satfractqiuha (signed char 2419 A) 2420 -- Runtime Function: unsigned accum __satfractqiusa (signed char A) 2421 -- Runtime Function: unsigned long accum __satfractqiuda (signed char 2422 A) 2423 -- Runtime Function: unsigned long long accum __satfractqiuta (signed 2424 char A) 2425 -- Runtime Function: short fract __satfracthiqq (short A) 2426 -- Runtime Function: fract __satfracthihq (short A) 2427 -- Runtime Function: long fract __satfracthisq (short A) 2428 -- Runtime Function: long long fract __satfracthidq (short A) 2429 -- Runtime Function: short accum __satfracthiha (short A) 2430 -- Runtime Function: accum __satfracthisa (short A) 2431 -- Runtime Function: long accum __satfracthida (short A) 2432 -- Runtime Function: long long accum __satfracthita (short A) 2433 -- Runtime Function: unsigned short fract __satfracthiuqq (short A) 2434 -- Runtime Function: unsigned fract __satfracthiuhq (short A) 2435 -- Runtime Function: unsigned long fract __satfracthiusq (short A) 2436 -- Runtime Function: unsigned long long fract __satfracthiudq (short A) 2437 -- Runtime Function: unsigned short accum __satfracthiuha (short A) 2438 -- Runtime Function: unsigned accum __satfracthiusa (short A) 2439 -- Runtime Function: unsigned long accum __satfracthiuda (short A) 2440 -- Runtime Function: unsigned long long accum __satfracthiuta (short A) 2441 -- Runtime Function: short fract __satfractsiqq (int A) 2442 -- Runtime Function: fract __satfractsihq (int A) 2443 -- Runtime Function: long fract __satfractsisq (int A) 2444 -- Runtime Function: long long fract __satfractsidq (int A) 2445 -- Runtime Function: short accum __satfractsiha (int A) 2446 -- Runtime Function: accum __satfractsisa (int A) 2447 -- Runtime Function: long accum __satfractsida (int A) 2448 -- Runtime Function: long long accum __satfractsita (int A) 2449 -- Runtime Function: unsigned short fract __satfractsiuqq (int A) 2450 -- Runtime Function: unsigned fract __satfractsiuhq (int A) 2451 -- Runtime Function: unsigned long fract __satfractsiusq (int A) 2452 -- Runtime Function: unsigned long long fract __satfractsiudq (int A) 2453 -- Runtime Function: unsigned short accum __satfractsiuha (int A) 2454 -- Runtime Function: unsigned accum __satfractsiusa (int A) 2455 -- Runtime Function: unsigned long accum __satfractsiuda (int A) 2456 -- Runtime Function: unsigned long long accum __satfractsiuta (int A) 2457 -- Runtime Function: short fract __satfractdiqq (long A) 2458 -- Runtime Function: fract __satfractdihq (long A) 2459 -- Runtime Function: long fract __satfractdisq (long A) 2460 -- Runtime Function: long long fract __satfractdidq (long A) 2461 -- Runtime Function: short accum __satfractdiha (long A) 2462 -- Runtime Function: accum __satfractdisa (long A) 2463 -- Runtime Function: long accum __satfractdida (long A) 2464 -- Runtime Function: long long accum __satfractdita (long A) 2465 -- Runtime Function: unsigned short fract __satfractdiuqq (long A) 2466 -- Runtime Function: unsigned fract __satfractdiuhq (long A) 2467 -- Runtime Function: unsigned long fract __satfractdiusq (long A) 2468 -- Runtime Function: unsigned long long fract __satfractdiudq (long A) 2469 -- Runtime Function: unsigned short accum __satfractdiuha (long A) 2470 -- Runtime Function: unsigned accum __satfractdiusa (long A) 2471 -- Runtime Function: unsigned long accum __satfractdiuda (long A) 2472 -- Runtime Function: unsigned long long accum __satfractdiuta (long A) 2473 -- Runtime Function: short fract __satfracttiqq (long long A) 2474 -- Runtime Function: fract __satfracttihq (long long A) 2475 -- Runtime Function: long fract __satfracttisq (long long A) 2476 -- Runtime Function: long long fract __satfracttidq (long long A) 2477 -- Runtime Function: short accum __satfracttiha (long long A) 2478 -- Runtime Function: accum __satfracttisa (long long A) 2479 -- Runtime Function: long accum __satfracttida (long long A) 2480 -- Runtime Function: long long accum __satfracttita (long long A) 2481 -- Runtime Function: unsigned short fract __satfracttiuqq (long long A) 2482 -- Runtime Function: unsigned fract __satfracttiuhq (long long A) 2483 -- Runtime Function: unsigned long fract __satfracttiusq (long long A) 2484 -- Runtime Function: unsigned long long fract __satfracttiudq (long 2485 long A) 2486 -- Runtime Function: unsigned short accum __satfracttiuha (long long A) 2487 -- Runtime Function: unsigned accum __satfracttiusa (long long A) 2488 -- Runtime Function: unsigned long accum __satfracttiuda (long long A) 2489 -- Runtime Function: unsigned long long accum __satfracttiuta (long 2490 long A) 2491 -- Runtime Function: short fract __satfractsfqq (float A) 2492 -- Runtime Function: fract __satfractsfhq (float A) 2493 -- Runtime Function: long fract __satfractsfsq (float A) 2494 -- Runtime Function: long long fract __satfractsfdq (float A) 2495 -- Runtime Function: short accum __satfractsfha (float A) 2496 -- Runtime Function: accum __satfractsfsa (float A) 2497 -- Runtime Function: long accum __satfractsfda (float A) 2498 -- Runtime Function: long long accum __satfractsfta (float A) 2499 -- Runtime Function: unsigned short fract __satfractsfuqq (float A) 2500 -- Runtime Function: unsigned fract __satfractsfuhq (float A) 2501 -- Runtime Function: unsigned long fract __satfractsfusq (float A) 2502 -- Runtime Function: unsigned long long fract __satfractsfudq (float A) 2503 -- Runtime Function: unsigned short accum __satfractsfuha (float A) 2504 -- Runtime Function: unsigned accum __satfractsfusa (float A) 2505 -- Runtime Function: unsigned long accum __satfractsfuda (float A) 2506 -- Runtime Function: unsigned long long accum __satfractsfuta (float A) 2507 -- Runtime Function: short fract __satfractdfqq (double A) 2508 -- Runtime Function: fract __satfractdfhq (double A) 2509 -- Runtime Function: long fract __satfractdfsq (double A) 2510 -- Runtime Function: long long fract __satfractdfdq (double A) 2511 -- Runtime Function: short accum __satfractdfha (double A) 2512 -- Runtime Function: accum __satfractdfsa (double A) 2513 -- Runtime Function: long accum __satfractdfda (double A) 2514 -- Runtime Function: long long accum __satfractdfta (double A) 2515 -- Runtime Function: unsigned short fract __satfractdfuqq (double A) 2516 -- Runtime Function: unsigned fract __satfractdfuhq (double A) 2517 -- Runtime Function: unsigned long fract __satfractdfusq (double A) 2518 -- Runtime Function: unsigned long long fract __satfractdfudq (double 2519 A) 2520 -- Runtime Function: unsigned short accum __satfractdfuha (double A) 2521 -- Runtime Function: unsigned accum __satfractdfusa (double A) 2522 -- Runtime Function: unsigned long accum __satfractdfuda (double A) 2523 -- Runtime Function: unsigned long long accum __satfractdfuta (double 2524 A) 2525 The functions convert from fractional and signed non-fractionals to 2526 fractionals, with saturation. 2527 2528 -- Runtime Function: unsigned char __fractunsqqqi (short fract A) 2529 -- Runtime Function: unsigned short __fractunsqqhi (short fract A) 2530 -- Runtime Function: unsigned int __fractunsqqsi (short fract A) 2531 -- Runtime Function: unsigned long __fractunsqqdi (short fract A) 2532 -- Runtime Function: unsigned long long __fractunsqqti (short fract A) 2533 -- Runtime Function: unsigned char __fractunshqqi (fract A) 2534 -- Runtime Function: unsigned short __fractunshqhi (fract A) 2535 -- Runtime Function: unsigned int __fractunshqsi (fract A) 2536 -- Runtime Function: unsigned long __fractunshqdi (fract A) 2537 -- Runtime Function: unsigned long long __fractunshqti (fract A) 2538 -- Runtime Function: unsigned char __fractunssqqi (long fract A) 2539 -- Runtime Function: unsigned short __fractunssqhi (long fract A) 2540 -- Runtime Function: unsigned int __fractunssqsi (long fract A) 2541 -- Runtime Function: unsigned long __fractunssqdi (long fract A) 2542 -- Runtime Function: unsigned long long __fractunssqti (long fract A) 2543 -- Runtime Function: unsigned char __fractunsdqqi (long long fract A) 2544 -- Runtime Function: unsigned short __fractunsdqhi (long long fract A) 2545 -- Runtime Function: unsigned int __fractunsdqsi (long long fract A) 2546 -- Runtime Function: unsigned long __fractunsdqdi (long long fract A) 2547 -- Runtime Function: unsigned long long __fractunsdqti (long long 2548 fract A) 2549 -- Runtime Function: unsigned char __fractunshaqi (short accum A) 2550 -- Runtime Function: unsigned short __fractunshahi (short accum A) 2551 -- Runtime Function: unsigned int __fractunshasi (short accum A) 2552 -- Runtime Function: unsigned long __fractunshadi (short accum A) 2553 -- Runtime Function: unsigned long long __fractunshati (short accum A) 2554 -- Runtime Function: unsigned char __fractunssaqi (accum A) 2555 -- Runtime Function: unsigned short __fractunssahi (accum A) 2556 -- Runtime Function: unsigned int __fractunssasi (accum A) 2557 -- Runtime Function: unsigned long __fractunssadi (accum A) 2558 -- Runtime Function: unsigned long long __fractunssati (accum A) 2559 -- Runtime Function: unsigned char __fractunsdaqi (long accum A) 2560 -- Runtime Function: unsigned short __fractunsdahi (long accum A) 2561 -- Runtime Function: unsigned int __fractunsdasi (long accum A) 2562 -- Runtime Function: unsigned long __fractunsdadi (long accum A) 2563 -- Runtime Function: unsigned long long __fractunsdati (long accum A) 2564 -- Runtime Function: unsigned char __fractunstaqi (long long accum A) 2565 -- Runtime Function: unsigned short __fractunstahi (long long accum A) 2566 -- Runtime Function: unsigned int __fractunstasi (long long accum A) 2567 -- Runtime Function: unsigned long __fractunstadi (long long accum A) 2568 -- Runtime Function: unsigned long long __fractunstati (long long 2569 accum A) 2570 -- Runtime Function: unsigned char __fractunsuqqqi (unsigned short 2571 fract A) 2572 -- Runtime Function: unsigned short __fractunsuqqhi (unsigned short 2573 fract A) 2574 -- Runtime Function: unsigned int __fractunsuqqsi (unsigned short 2575 fract A) 2576 -- Runtime Function: unsigned long __fractunsuqqdi (unsigned short 2577 fract A) 2578 -- Runtime Function: unsigned long long __fractunsuqqti (unsigned 2579 short fract A) 2580 -- Runtime Function: unsigned char __fractunsuhqqi (unsigned fract A) 2581 -- Runtime Function: unsigned short __fractunsuhqhi (unsigned fract A) 2582 -- Runtime Function: unsigned int __fractunsuhqsi (unsigned fract A) 2583 -- Runtime Function: unsigned long __fractunsuhqdi (unsigned fract A) 2584 -- Runtime Function: unsigned long long __fractunsuhqti (unsigned 2585 fract A) 2586 -- Runtime Function: unsigned char __fractunsusqqi (unsigned long 2587 fract A) 2588 -- Runtime Function: unsigned short __fractunsusqhi (unsigned long 2589 fract A) 2590 -- Runtime Function: unsigned int __fractunsusqsi (unsigned long fract 2591 A) 2592 -- Runtime Function: unsigned long __fractunsusqdi (unsigned long 2593 fract A) 2594 -- Runtime Function: unsigned long long __fractunsusqti (unsigned long 2595 fract A) 2596 -- Runtime Function: unsigned char __fractunsudqqi (unsigned long long 2597 fract A) 2598 -- Runtime Function: unsigned short __fractunsudqhi (unsigned long 2599 long fract A) 2600 -- Runtime Function: unsigned int __fractunsudqsi (unsigned long long 2601 fract A) 2602 -- Runtime Function: unsigned long __fractunsudqdi (unsigned long long 2603 fract A) 2604 -- Runtime Function: unsigned long long __fractunsudqti (unsigned long 2605 long fract A) 2606 -- Runtime Function: unsigned char __fractunsuhaqi (unsigned short 2607 accum A) 2608 -- Runtime Function: unsigned short __fractunsuhahi (unsigned short 2609 accum A) 2610 -- Runtime Function: unsigned int __fractunsuhasi (unsigned short 2611 accum A) 2612 -- Runtime Function: unsigned long __fractunsuhadi (unsigned short 2613 accum A) 2614 -- Runtime Function: unsigned long long __fractunsuhati (unsigned 2615 short accum A) 2616 -- Runtime Function: unsigned char __fractunsusaqi (unsigned accum A) 2617 -- Runtime Function: unsigned short __fractunsusahi (unsigned accum A) 2618 -- Runtime Function: unsigned int __fractunsusasi (unsigned accum A) 2619 -- Runtime Function: unsigned long __fractunsusadi (unsigned accum A) 2620 -- Runtime Function: unsigned long long __fractunsusati (unsigned 2621 accum A) 2622 -- Runtime Function: unsigned char __fractunsudaqi (unsigned long 2623 accum A) 2624 -- Runtime Function: unsigned short __fractunsudahi (unsigned long 2625 accum A) 2626 -- Runtime Function: unsigned int __fractunsudasi (unsigned long accum 2627 A) 2628 -- Runtime Function: unsigned long __fractunsudadi (unsigned long 2629 accum A) 2630 -- Runtime Function: unsigned long long __fractunsudati (unsigned long 2631 accum A) 2632 -- Runtime Function: unsigned char __fractunsutaqi (unsigned long long 2633 accum A) 2634 -- Runtime Function: unsigned short __fractunsutahi (unsigned long 2635 long accum A) 2636 -- Runtime Function: unsigned int __fractunsutasi (unsigned long long 2637 accum A) 2638 -- Runtime Function: unsigned long __fractunsutadi (unsigned long long 2639 accum A) 2640 -- Runtime Function: unsigned long long __fractunsutati (unsigned long 2641 long accum A) 2642 -- Runtime Function: short fract __fractunsqiqq (unsigned char A) 2643 -- Runtime Function: fract __fractunsqihq (unsigned char A) 2644 -- Runtime Function: long fract __fractunsqisq (unsigned char A) 2645 -- Runtime Function: long long fract __fractunsqidq (unsigned char A) 2646 -- Runtime Function: short accum __fractunsqiha (unsigned char A) 2647 -- Runtime Function: accum __fractunsqisa (unsigned char A) 2648 -- Runtime Function: long accum __fractunsqida (unsigned char A) 2649 -- Runtime Function: long long accum __fractunsqita (unsigned char A) 2650 -- Runtime Function: unsigned short fract __fractunsqiuqq (unsigned 2651 char A) 2652 -- Runtime Function: unsigned fract __fractunsqiuhq (unsigned char A) 2653 -- Runtime Function: unsigned long fract __fractunsqiusq (unsigned 2654 char A) 2655 -- Runtime Function: unsigned long long fract __fractunsqiudq 2656 (unsigned char A) 2657 -- Runtime Function: unsigned short accum __fractunsqiuha (unsigned 2658 char A) 2659 -- Runtime Function: unsigned accum __fractunsqiusa (unsigned char A) 2660 -- Runtime Function: unsigned long accum __fractunsqiuda (unsigned 2661 char A) 2662 -- Runtime Function: unsigned long long accum __fractunsqiuta 2663 (unsigned char A) 2664 -- Runtime Function: short fract __fractunshiqq (unsigned short A) 2665 -- Runtime Function: fract __fractunshihq (unsigned short A) 2666 -- Runtime Function: long fract __fractunshisq (unsigned short A) 2667 -- Runtime Function: long long fract __fractunshidq (unsigned short A) 2668 -- Runtime Function: short accum __fractunshiha (unsigned short A) 2669 -- Runtime Function: accum __fractunshisa (unsigned short A) 2670 -- Runtime Function: long accum __fractunshida (unsigned short A) 2671 -- Runtime Function: long long accum __fractunshita (unsigned short A) 2672 -- Runtime Function: unsigned short fract __fractunshiuqq (unsigned 2673 short A) 2674 -- Runtime Function: unsigned fract __fractunshiuhq (unsigned short A) 2675 -- Runtime Function: unsigned long fract __fractunshiusq (unsigned 2676 short A) 2677 -- Runtime Function: unsigned long long fract __fractunshiudq 2678 (unsigned short A) 2679 -- Runtime Function: unsigned short accum __fractunshiuha (unsigned 2680 short A) 2681 -- Runtime Function: unsigned accum __fractunshiusa (unsigned short A) 2682 -- Runtime Function: unsigned long accum __fractunshiuda (unsigned 2683 short A) 2684 -- Runtime Function: unsigned long long accum __fractunshiuta 2685 (unsigned short A) 2686 -- Runtime Function: short fract __fractunssiqq (unsigned int A) 2687 -- Runtime Function: fract __fractunssihq (unsigned int A) 2688 -- Runtime Function: long fract __fractunssisq (unsigned int A) 2689 -- Runtime Function: long long fract __fractunssidq (unsigned int A) 2690 -- Runtime Function: short accum __fractunssiha (unsigned int A) 2691 -- Runtime Function: accum __fractunssisa (unsigned int A) 2692 -- Runtime Function: long accum __fractunssida (unsigned int A) 2693 -- Runtime Function: long long accum __fractunssita (unsigned int A) 2694 -- Runtime Function: unsigned short fract __fractunssiuqq (unsigned 2695 int A) 2696 -- Runtime Function: unsigned fract __fractunssiuhq (unsigned int A) 2697 -- Runtime Function: unsigned long fract __fractunssiusq (unsigned int 2698 A) 2699 -- Runtime Function: unsigned long long fract __fractunssiudq 2700 (unsigned int A) 2701 -- Runtime Function: unsigned short accum __fractunssiuha (unsigned 2702 int A) 2703 -- Runtime Function: unsigned accum __fractunssiusa (unsigned int A) 2704 -- Runtime Function: unsigned long accum __fractunssiuda (unsigned int 2705 A) 2706 -- Runtime Function: unsigned long long accum __fractunssiuta 2707 (unsigned int A) 2708 -- Runtime Function: short fract __fractunsdiqq (unsigned long A) 2709 -- Runtime Function: fract __fractunsdihq (unsigned long A) 2710 -- Runtime Function: long fract __fractunsdisq (unsigned long A) 2711 -- Runtime Function: long long fract __fractunsdidq (unsigned long A) 2712 -- Runtime Function: short accum __fractunsdiha (unsigned long A) 2713 -- Runtime Function: accum __fractunsdisa (unsigned long A) 2714 -- Runtime Function: long accum __fractunsdida (unsigned long A) 2715 -- Runtime Function: long long accum __fractunsdita (unsigned long A) 2716 -- Runtime Function: unsigned short fract __fractunsdiuqq (unsigned 2717 long A) 2718 -- Runtime Function: unsigned fract __fractunsdiuhq (unsigned long A) 2719 -- Runtime Function: unsigned long fract __fractunsdiusq (unsigned 2720 long A) 2721 -- Runtime Function: unsigned long long fract __fractunsdiudq 2722 (unsigned long A) 2723 -- Runtime Function: unsigned short accum __fractunsdiuha (unsigned 2724 long A) 2725 -- Runtime Function: unsigned accum __fractunsdiusa (unsigned long A) 2726 -- Runtime Function: unsigned long accum __fractunsdiuda (unsigned 2727 long A) 2728 -- Runtime Function: unsigned long long accum __fractunsdiuta 2729 (unsigned long A) 2730 -- Runtime Function: short fract __fractunstiqq (unsigned long long A) 2731 -- Runtime Function: fract __fractunstihq (unsigned long long A) 2732 -- Runtime Function: long fract __fractunstisq (unsigned long long A) 2733 -- Runtime Function: long long fract __fractunstidq (unsigned long 2734 long A) 2735 -- Runtime Function: short accum __fractunstiha (unsigned long long A) 2736 -- Runtime Function: accum __fractunstisa (unsigned long long A) 2737 -- Runtime Function: long accum __fractunstida (unsigned long long A) 2738 -- Runtime Function: long long accum __fractunstita (unsigned long 2739 long A) 2740 -- Runtime Function: unsigned short fract __fractunstiuqq (unsigned 2741 long long A) 2742 -- Runtime Function: unsigned fract __fractunstiuhq (unsigned long 2743 long A) 2744 -- Runtime Function: unsigned long fract __fractunstiusq (unsigned 2745 long long A) 2746 -- Runtime Function: unsigned long long fract __fractunstiudq 2747 (unsigned long long A) 2748 -- Runtime Function: unsigned short accum __fractunstiuha (unsigned 2749 long long A) 2750 -- Runtime Function: unsigned accum __fractunstiusa (unsigned long 2751 long A) 2752 -- Runtime Function: unsigned long accum __fractunstiuda (unsigned 2753 long long A) 2754 -- Runtime Function: unsigned long long accum __fractunstiuta 2755 (unsigned long long A) 2756 These functions convert from fractionals to unsigned 2757 non-fractionals; and from unsigned non-fractionals to fractionals, 2758 without saturation. 2759 2760 -- Runtime Function: short fract __satfractunsqiqq (unsigned char A) 2761 -- Runtime Function: fract __satfractunsqihq (unsigned char A) 2762 -- Runtime Function: long fract __satfractunsqisq (unsigned char A) 2763 -- Runtime Function: long long fract __satfractunsqidq (unsigned char 2764 A) 2765 -- Runtime Function: short accum __satfractunsqiha (unsigned char A) 2766 -- Runtime Function: accum __satfractunsqisa (unsigned char A) 2767 -- Runtime Function: long accum __satfractunsqida (unsigned char A) 2768 -- Runtime Function: long long accum __satfractunsqita (unsigned char 2769 A) 2770 -- Runtime Function: unsigned short fract __satfractunsqiuqq (unsigned 2771 char A) 2772 -- Runtime Function: unsigned fract __satfractunsqiuhq (unsigned char 2773 A) 2774 -- Runtime Function: unsigned long fract __satfractunsqiusq (unsigned 2775 char A) 2776 -- Runtime Function: unsigned long long fract __satfractunsqiudq 2777 (unsigned char A) 2778 -- Runtime Function: unsigned short accum __satfractunsqiuha (unsigned 2779 char A) 2780 -- Runtime Function: unsigned accum __satfractunsqiusa (unsigned char 2781 A) 2782 -- Runtime Function: unsigned long accum __satfractunsqiuda (unsigned 2783 char A) 2784 -- Runtime Function: unsigned long long accum __satfractunsqiuta 2785 (unsigned char A) 2786 -- Runtime Function: short fract __satfractunshiqq (unsigned short A) 2787 -- Runtime Function: fract __satfractunshihq (unsigned short A) 2788 -- Runtime Function: long fract __satfractunshisq (unsigned short A) 2789 -- Runtime Function: long long fract __satfractunshidq (unsigned short 2790 A) 2791 -- Runtime Function: short accum __satfractunshiha (unsigned short A) 2792 -- Runtime Function: accum __satfractunshisa (unsigned short A) 2793 -- Runtime Function: long accum __satfractunshida (unsigned short A) 2794 -- Runtime Function: long long accum __satfractunshita (unsigned short 2795 A) 2796 -- Runtime Function: unsigned short fract __satfractunshiuqq (unsigned 2797 short A) 2798 -- Runtime Function: unsigned fract __satfractunshiuhq (unsigned short 2799 A) 2800 -- Runtime Function: unsigned long fract __satfractunshiusq (unsigned 2801 short A) 2802 -- Runtime Function: unsigned long long fract __satfractunshiudq 2803 (unsigned short A) 2804 -- Runtime Function: unsigned short accum __satfractunshiuha (unsigned 2805 short A) 2806 -- Runtime Function: unsigned accum __satfractunshiusa (unsigned short 2807 A) 2808 -- Runtime Function: unsigned long accum __satfractunshiuda (unsigned 2809 short A) 2810 -- Runtime Function: unsigned long long accum __satfractunshiuta 2811 (unsigned short A) 2812 -- Runtime Function: short fract __satfractunssiqq (unsigned int A) 2813 -- Runtime Function: fract __satfractunssihq (unsigned int A) 2814 -- Runtime Function: long fract __satfractunssisq (unsigned int A) 2815 -- Runtime Function: long long fract __satfractunssidq (unsigned int A) 2816 -- Runtime Function: short accum __satfractunssiha (unsigned int A) 2817 -- Runtime Function: accum __satfractunssisa (unsigned int A) 2818 -- Runtime Function: long accum __satfractunssida (unsigned int A) 2819 -- Runtime Function: long long accum __satfractunssita (unsigned int A) 2820 -- Runtime Function: unsigned short fract __satfractunssiuqq (unsigned 2821 int A) 2822 -- Runtime Function: unsigned fract __satfractunssiuhq (unsigned int A) 2823 -- Runtime Function: unsigned long fract __satfractunssiusq (unsigned 2824 int A) 2825 -- Runtime Function: unsigned long long fract __satfractunssiudq 2826 (unsigned int A) 2827 -- Runtime Function: unsigned short accum __satfractunssiuha (unsigned 2828 int A) 2829 -- Runtime Function: unsigned accum __satfractunssiusa (unsigned int A) 2830 -- Runtime Function: unsigned long accum __satfractunssiuda (unsigned 2831 int A) 2832 -- Runtime Function: unsigned long long accum __satfractunssiuta 2833 (unsigned int A) 2834 -- Runtime Function: short fract __satfractunsdiqq (unsigned long A) 2835 -- Runtime Function: fract __satfractunsdihq (unsigned long A) 2836 -- Runtime Function: long fract __satfractunsdisq (unsigned long A) 2837 -- Runtime Function: long long fract __satfractunsdidq (unsigned long 2838 A) 2839 -- Runtime Function: short accum __satfractunsdiha (unsigned long A) 2840 -- Runtime Function: accum __satfractunsdisa (unsigned long A) 2841 -- Runtime Function: long accum __satfractunsdida (unsigned long A) 2842 -- Runtime Function: long long accum __satfractunsdita (unsigned long 2843 A) 2844 -- Runtime Function: unsigned short fract __satfractunsdiuqq (unsigned 2845 long A) 2846 -- Runtime Function: unsigned fract __satfractunsdiuhq (unsigned long 2847 A) 2848 -- Runtime Function: unsigned long fract __satfractunsdiusq (unsigned 2849 long A) 2850 -- Runtime Function: unsigned long long fract __satfractunsdiudq 2851 (unsigned long A) 2852 -- Runtime Function: unsigned short accum __satfractunsdiuha (unsigned 2853 long A) 2854 -- Runtime Function: unsigned accum __satfractunsdiusa (unsigned long 2855 A) 2856 -- Runtime Function: unsigned long accum __satfractunsdiuda (unsigned 2857 long A) 2858 -- Runtime Function: unsigned long long accum __satfractunsdiuta 2859 (unsigned long A) 2860 -- Runtime Function: short fract __satfractunstiqq (unsigned long long 2861 A) 2862 -- Runtime Function: fract __satfractunstihq (unsigned long long A) 2863 -- Runtime Function: long fract __satfractunstisq (unsigned long long 2864 A) 2865 -- Runtime Function: long long fract __satfractunstidq (unsigned long 2866 long A) 2867 -- Runtime Function: short accum __satfractunstiha (unsigned long long 2868 A) 2869 -- Runtime Function: accum __satfractunstisa (unsigned long long A) 2870 -- Runtime Function: long accum __satfractunstida (unsigned long long 2871 A) 2872 -- Runtime Function: long long accum __satfractunstita (unsigned long 2873 long A) 2874 -- Runtime Function: unsigned short fract __satfractunstiuqq (unsigned 2875 long long A) 2876 -- Runtime Function: unsigned fract __satfractunstiuhq (unsigned long 2877 long A) 2878 -- Runtime Function: unsigned long fract __satfractunstiusq (unsigned 2879 long long A) 2880 -- Runtime Function: unsigned long long fract __satfractunstiudq 2881 (unsigned long long A) 2882 -- Runtime Function: unsigned short accum __satfractunstiuha (unsigned 2883 long long A) 2884 -- Runtime Function: unsigned accum __satfractunstiusa (unsigned long 2885 long A) 2886 -- Runtime Function: unsigned long accum __satfractunstiuda (unsigned 2887 long long A) 2888 -- Runtime Function: unsigned long long accum __satfractunstiuta 2889 (unsigned long long A) 2890 These functions convert from unsigned non-fractionals to 2891 fractionals, with saturation. 2892 2893 2894 File: gccint.info, Node: Exception handling routines, Next: Miscellaneous routines, Prev: Fixed-point fractional library routines, Up: Libgcc 2895 2896 4.5 Language-independent routines for exception handling 2897 ======================================================== 2898 2899 document me! 2900 2901 _Unwind_DeleteException 2902 _Unwind_Find_FDE 2903 _Unwind_ForcedUnwind 2904 _Unwind_GetGR 2905 _Unwind_GetIP 2906 _Unwind_GetLanguageSpecificData 2907 _Unwind_GetRegionStart 2908 _Unwind_GetTextRelBase 2909 _Unwind_GetDataRelBase 2910 _Unwind_RaiseException 2911 _Unwind_Resume 2912 _Unwind_SetGR 2913 _Unwind_SetIP 2914 _Unwind_FindEnclosingFunction 2915 _Unwind_SjLj_Register 2916 _Unwind_SjLj_Unregister 2917 _Unwind_SjLj_RaiseException 2918 _Unwind_SjLj_ForcedUnwind 2919 _Unwind_SjLj_Resume 2920 __deregister_frame 2921 __deregister_frame_info 2922 __deregister_frame_info_bases 2923 __register_frame 2924 __register_frame_info 2925 __register_frame_info_bases 2926 __register_frame_info_table 2927 __register_frame_info_table_bases 2928 __register_frame_table 2929 2930 2931 File: gccint.info, Node: Miscellaneous routines, Prev: Exception handling routines, Up: Libgcc 2932 2933 4.6 Miscellaneous runtime library routines 2934 ========================================== 2935 2936 4.6.1 Cache control functions 2937 ----------------------------- 2938 2939 -- Runtime Function: void __clear_cache (char *BEG, char *END) 2940 This function clears the instruction cache between BEG and END. 2941 2942 2943 File: gccint.info, Node: Languages, Next: Source Tree, Prev: Libgcc, Up: Top 2944 2945 5 Language Front Ends in GCC 2946 **************************** 2947 2948 The interface to front ends for languages in GCC, and in particular the 2949 `tree' structure (*note Trees::), was initially designed for C, and 2950 many aspects of it are still somewhat biased towards C and C-like 2951 languages. It is, however, reasonably well suited to other procedural 2952 languages, and front ends for many such languages have been written for 2953 GCC. 2954 2955 Writing a compiler as a front end for GCC, rather than compiling 2956 directly to assembler or generating C code which is then compiled by 2957 GCC, has several advantages: 2958 2959 * GCC front ends benefit from the support for many different target 2960 machines already present in GCC. 2961 2962 * GCC front ends benefit from all the optimizations in GCC. Some of 2963 these, such as alias analysis, may work better when GCC is 2964 compiling directly from source code then when it is compiling from 2965 generated C code. 2966 2967 * Better debugging information is generated when compiling directly 2968 from source code than when going via intermediate generated C code. 2969 2970 Because of the advantages of writing a compiler as a GCC front end, 2971 GCC front ends have also been created for languages very different from 2972 those for which GCC was designed, such as the declarative 2973 logic/functional language Mercury. For these reasons, it may also be 2974 useful to implement compilers created for specialized purposes (for 2975 example, as part of a research project) as GCC front ends. 2976 2977 2978 File: gccint.info, Node: Source Tree, Next: Options, Prev: Languages, Up: Top 2979 2980 6 Source Tree Structure and Build System 2981 **************************************** 2982 2983 This chapter describes the structure of the GCC source tree, and how 2984 GCC is built. The user documentation for building and installing GCC 2985 is in a separate manual (`http://gcc.gnu.org/install/'), with which it 2986 is presumed that you are familiar. 2987 2988 * Menu: 2989 2990 * Configure Terms:: Configuration terminology and history. 2991 * Top Level:: The top level source directory. 2992 * gcc Directory:: The `gcc' subdirectory. 2993 * Testsuites:: The GCC testsuites. 2994 2995 2996 File: gccint.info, Node: Configure Terms, Next: Top Level, Up: Source Tree 2997 2998 6.1 Configure Terms and History 2999 =============================== 3000 3001 The configure and build process has a long and colorful history, and can 3002 be confusing to anyone who doesn't know why things are the way they are. 3003 While there are other documents which describe the configuration process 3004 in detail, here are a few things that everyone working on GCC should 3005 know. 3006 3007 There are three system names that the build knows about: the machine 3008 you are building on ("build"), the machine that you are building for 3009 ("host"), and the machine that GCC will produce code for ("target"). 3010 When you configure GCC, you specify these with `--build=', `--host=', 3011 and `--target='. 3012 3013 Specifying the host without specifying the build should be avoided, as 3014 `configure' may (and once did) assume that the host you specify is also 3015 the build, which may not be true. 3016 3017 If build, host, and target are all the same, this is called a 3018 "native". If build and host are the same but target is different, this 3019 is called a "cross". If build, host, and target are all different this 3020 is called a "canadian" (for obscure reasons dealing with Canada's 3021 political party and the background of the person working on the build 3022 at that time). If host and target are the same, but build is 3023 different, you are using a cross-compiler to build a native for a 3024 different system. Some people call this a "host-x-host", "crossed 3025 native", or "cross-built native". If build and target are the same, 3026 but host is different, you are using a cross compiler to build a cross 3027 compiler that produces code for the machine you're building on. This 3028 is rare, so there is no common way of describing it. There is a 3029 proposal to call this a "crossback". 3030 3031 If build and host are the same, the GCC you are building will also be 3032 used to build the target libraries (like `libstdc++'). If build and 3033 host are different, you must have already built and installed a cross 3034 compiler that will be used to build the target libraries (if you 3035 configured with `--target=foo-bar', this compiler will be called 3036 `foo-bar-gcc'). 3037 3038 In the case of target libraries, the machine you're building for is the 3039 machine you specified with `--target'. So, build is the machine you're 3040 building on (no change there), host is the machine you're building for 3041 (the target libraries are built for the target, so host is the target 3042 you specified), and target doesn't apply (because you're not building a 3043 compiler, you're building libraries). The configure/make process will 3044 adjust these variables as needed. It also sets `$with_cross_host' to 3045 the original `--host' value in case you need it. 3046 3047 The `libiberty' support library is built up to three times: once for 3048 the host, once for the target (even if they are the same), and once for 3049 the build if build and host are different. This allows it to be used 3050 by all programs which are generated in the course of the build process. 3051 3052 3053 File: gccint.info, Node: Top Level, Next: gcc Directory, Prev: Configure Terms, Up: Source Tree 3054 3055 6.2 Top Level Source Directory 3056 ============================== 3057 3058 The top level source directory in a GCC distribution contains several 3059 files and directories that are shared with other software distributions 3060 such as that of GNU Binutils. It also contains several subdirectories 3061 that contain parts of GCC and its runtime libraries: 3062 3063 `boehm-gc' 3064 The Boehm conservative garbage collector, used as part of the Java 3065 runtime library. 3066 3067 `contrib' 3068 Contributed scripts that may be found useful in conjunction with 3069 GCC. One of these, `contrib/texi2pod.pl', is used to generate man 3070 pages from Texinfo manuals as part of the GCC build process. 3071 3072 `fastjar' 3073 An implementation of the `jar' command, used with the Java front 3074 end. 3075 3076 `fixincludes' 3077 The support for fixing system headers to work with GCC. See 3078 `fixincludes/README' for more information. The headers fixed by 3079 this mechanism are installed in `LIBSUBDIR/include-fixed'. Along 3080 with those headers, `README-fixinc' is also installed, as 3081 `LIBSUBDIR/include-fixed/README'. 3082 3083 `gcc' 3084 The main sources of GCC itself (except for runtime libraries), 3085 including optimizers, support for different target architectures, 3086 language front ends, and testsuites. *Note The `gcc' 3087 Subdirectory: gcc Directory, for details. 3088 3089 `include' 3090 Headers for the `libiberty' library. 3091 3092 `intl' 3093 GNU `libintl', from GNU `gettext', for systems which do not 3094 include it in libc. 3095 3096 `libada' 3097 The Ada runtime library. 3098 3099 `libcpp' 3100 The C preprocessor library. 3101 3102 `libgfortran' 3103 The Fortran runtime library. 3104 3105 `libffi' 3106 The `libffi' library, used as part of the Java runtime library. 3107 3108 `libiberty' 3109 The `libiberty' library, used for portability and for some 3110 generally useful data structures and algorithms. *Note 3111 Introduction: (libiberty)Top, for more information about this 3112 library. 3113 3114 `libjava' 3115 The Java runtime library. 3116 3117 `libmudflap' 3118 The `libmudflap' library, used for instrumenting pointer and array 3119 dereferencing operations. 3120 3121 `libobjc' 3122 The Objective-C and Objective-C++ runtime library. 3123 3124 `libstdc++-v3' 3125 The C++ runtime library. 3126 3127 `maintainer-scripts' 3128 Scripts used by the `gccadmin' account on `gcc.gnu.org'. 3129 3130 `zlib' 3131 The `zlib' compression library, used by the Java front end and as 3132 part of the Java runtime library. 3133 3134 The build system in the top level directory, including how recursion 3135 into subdirectories works and how building runtime libraries for 3136 multilibs is handled, is documented in a separate manual, included with 3137 GNU Binutils. *Note GNU configure and build system: (configure)Top, 3138 for details. 3139 3140 3141 File: gccint.info, Node: gcc Directory, Next: Testsuites, Prev: Top Level, Up: Source Tree 3142 3143 6.3 The `gcc' Subdirectory 3144 ========================== 3145 3146 The `gcc' directory contains many files that are part of the C sources 3147 of GCC, other files used as part of the configuration and build 3148 process, and subdirectories including documentation and a testsuite. 3149 The files that are sources of GCC are documented in a separate chapter. 3150 *Note Passes and Files of the Compiler: Passes. 3151 3152 * Menu: 3153 3154 * Subdirectories:: Subdirectories of `gcc'. 3155 * Configuration:: The configuration process, and the files it uses. 3156 * Build:: The build system in the `gcc' directory. 3157 * Makefile:: Targets in `gcc/Makefile'. 3158 * Library Files:: Library source files and headers under `gcc/'. 3159 * Headers:: Headers installed by GCC. 3160 * Documentation:: Building documentation in GCC. 3161 * Front End:: Anatomy of a language front end. 3162 * Back End:: Anatomy of a target back end. 3163 3164 3165 File: gccint.info, Node: Subdirectories, Next: Configuration, Up: gcc Directory 3166 3167 6.3.1 Subdirectories of `gcc' 3168 ----------------------------- 3169 3170 The `gcc' directory contains the following subdirectories: 3171 3172 `LANGUAGE' 3173 Subdirectories for various languages. Directories containing a 3174 file `config-lang.in' are language subdirectories. The contents of 3175 the subdirectories `cp' (for C++), `objc' (for Objective-C) and 3176 `objcp' (for Objective-C++) are documented in this manual (*note 3177 Passes and Files of the Compiler: Passes.); those for other 3178 languages are not. *Note Anatomy of a Language Front End: Front 3179 End, for details of the files in these directories. 3180 3181 `config' 3182 Configuration files for supported architectures and operating 3183 systems. *Note Anatomy of a Target Back End: Back End, for 3184 details of the files in this directory. 3185 3186 `doc' 3187 Texinfo documentation for GCC, together with automatically 3188 generated man pages and support for converting the installation 3189 manual to HTML. *Note Documentation::. 3190 3191 `ginclude' 3192 System headers installed by GCC, mainly those required by the C 3193 standard of freestanding implementations. *Note Headers Installed 3194 by GCC: Headers, for details of when these and other headers are 3195 installed. 3196 3197 `po' 3198 Message catalogs with translations of messages produced by GCC into 3199 various languages, `LANGUAGE.po'. This directory also contains 3200 `gcc.pot', the template for these message catalogues, `exgettext', 3201 a wrapper around `gettext' to extract the messages from the GCC 3202 sources and create `gcc.pot', which is run by `make gcc.pot', and 3203 `EXCLUDES', a list of files from which messages should not be 3204 extracted. 3205 3206 `testsuite' 3207 The GCC testsuites (except for those for runtime libraries). 3208 *Note Testsuites::. 3209 3210 3211 File: gccint.info, Node: Configuration, Next: Build, Prev: Subdirectories, Up: gcc Directory 3212 3213 6.3.2 Configuration in the `gcc' Directory 3214 ------------------------------------------ 3215 3216 The `gcc' directory is configured with an Autoconf-generated script 3217 `configure'. The `configure' script is generated from `configure.ac' 3218 and `aclocal.m4'. From the files `configure.ac' and `acconfig.h', 3219 Autoheader generates the file `config.in'. The file `cstamp-h.in' is 3220 used as a timestamp. 3221 3222 * Menu: 3223 3224 * Config Fragments:: Scripts used by `configure'. 3225 * System Config:: The `config.build', `config.host', and 3226 `config.gcc' files. 3227 * Configuration Files:: Files created by running `configure'. 3228 3229 3230 File: gccint.info, Node: Config Fragments, Next: System Config, Up: Configuration 3231 3232 6.3.2.1 Scripts Used by `configure' 3233 ................................... 3234 3235 `configure' uses some other scripts to help in its work: 3236 3237 * The standard GNU `config.sub' and `config.guess' files, kept in 3238 the top level directory, are used. 3239 3240 * The file `config.gcc' is used to handle configuration specific to 3241 the particular target machine. The file `config.build' is used to 3242 handle configuration specific to the particular build machine. 3243 The file `config.host' is used to handle configuration specific to 3244 the particular host machine. (In general, these should only be 3245 used for features that cannot reasonably be tested in Autoconf 3246 feature tests.) *Note The `config.build'; `config.host'; and 3247 `config.gcc' Files: System Config, for details of the contents of 3248 these files. 3249 3250 * Each language subdirectory has a file `LANGUAGE/config-lang.in' 3251 that is used for front-end-specific configuration. *Note The 3252 Front End `config-lang.in' File: Front End Config, for details of 3253 this file. 3254 3255 * A helper script `configure.frag' is used as part of creating the 3256 output of `configure'. 3257 3258 3259 File: gccint.info, Node: System Config, Next: Configuration Files, Prev: Config Fragments, Up: Configuration 3260 3261 6.3.2.2 The `config.build'; `config.host'; and `config.gcc' Files 3262 ................................................................. 3263 3264 The `config.build' file contains specific rules for particular systems 3265 which GCC is built on. This should be used as rarely as possible, as 3266 the behavior of the build system can always be detected by autoconf. 3267 3268 The `config.host' file contains specific rules for particular systems 3269 which GCC will run on. This is rarely needed. 3270 3271 The `config.gcc' file contains specific rules for particular systems 3272 which GCC will generate code for. This is usually needed. 3273 3274 Each file has a list of the shell variables it sets, with 3275 descriptions, at the top of the file. 3276 3277 FIXME: document the contents of these files, and what variables should 3278 be set to control build, host and target configuration. 3279 3280 3281 File: gccint.info, Node: Configuration Files, Prev: System Config, Up: Configuration 3282 3283 6.3.2.3 Files Created by `configure' 3284 .................................... 3285 3286 Here we spell out what files will be set up by `configure' in the `gcc' 3287 directory. Some other files are created as temporary files in the 3288 configuration process, and are not used in the subsequent build; these 3289 are not documented. 3290 3291 * `Makefile' is constructed from `Makefile.in', together with the 3292 host and target fragments (*note Makefile Fragments: Fragments.) 3293 `t-TARGET' and `x-HOST' from `config', if any, and language 3294 Makefile fragments `LANGUAGE/Make-lang.in'. 3295 3296 * `auto-host.h' contains information about the host machine 3297 determined by `configure'. If the host machine is different from 3298 the build machine, then `auto-build.h' is also created, containing 3299 such information about the build machine. 3300 3301 * `config.status' is a script that may be run to recreate the 3302 current configuration. 3303 3304 * `configargs.h' is a header containing details of the arguments 3305 passed to `configure' to configure GCC, and of the thread model 3306 used. 3307 3308 * `cstamp-h' is used as a timestamp. 3309 3310 * `fixinc/Makefile' is constructed from `fixinc/Makefile.in'. 3311 3312 * `gccbug', a script for reporting bugs in GCC, is constructed from 3313 `gccbug.in'. 3314 3315 * `intl/Makefile' is constructed from `intl/Makefile.in'. 3316 3317 * If a language `config-lang.in' file (*note The Front End 3318 `config-lang.in' File: Front End Config.) sets `outputs', then the 3319 files listed in `outputs' there are also generated. 3320 3321 The following configuration headers are created from the Makefile, 3322 using `mkconfig.sh', rather than directly by `configure'. `config.h', 3323 `bconfig.h' and `tconfig.h' all contain the `xm-MACHINE.h' header, if 3324 any, appropriate to the host, build and target machines respectively, 3325 the configuration headers for the target, and some definitions; for the 3326 host and build machines, these include the autoconfigured headers 3327 generated by `configure'. The other configuration headers are 3328 determined by `config.gcc'. They also contain the typedefs for `rtx', 3329 `rtvec' and `tree'. 3330 3331 * `config.h', for use in programs that run on the host machine. 3332 3333 * `bconfig.h', for use in programs that run on the build machine. 3334 3335 * `tconfig.h', for use in programs and libraries for the target 3336 machine. 3337 3338 * `tm_p.h', which includes the header `MACHINE-protos.h' that 3339 contains prototypes for functions in the target `.c' file. FIXME: 3340 why is such a separate header necessary? 3341 3342 3343 File: gccint.info, Node: Build, Next: Makefile, Prev: Configuration, Up: gcc Directory 3344 3345 6.3.3 Build System in the `gcc' Directory 3346 ----------------------------------------- 3347 3348 FIXME: describe the build system, including what is built in what 3349 stages. Also list the various source files that are used in the build 3350 process but aren't source files of GCC itself and so aren't documented 3351 below (*note Passes::). 3352 3353 3354 File: gccint.info, Node: Makefile, Next: Library Files, Prev: Build, Up: gcc Directory 3355 3356 6.3.4 Makefile Targets 3357 ---------------------- 3358 3359 These targets are available from the `gcc' directory: 3360 3361 `all' 3362 This is the default target. Depending on what your 3363 build/host/target configuration is, it coordinates all the things 3364 that need to be built. 3365 3366 `doc' 3367 Produce info-formatted documentation and man pages. Essentially it 3368 calls `make man' and `make info'. 3369 3370 `dvi' 3371 Produce DVI-formatted documentation. 3372 3373 `pdf' 3374 Produce PDF-formatted documentation. 3375 3376 `html' 3377 Produce HTML-formatted documentation. 3378 3379 `man' 3380 Generate man pages. 3381 3382 `info' 3383 Generate info-formatted pages. 3384 3385 `mostlyclean' 3386 Delete the files made while building the compiler. 3387 3388 `clean' 3389 That, and all the other files built by `make all'. 3390 3391 `distclean' 3392 That, and all the files created by `configure'. 3393 3394 `maintainer-clean' 3395 Distclean plus any file that can be generated from other files. 3396 Note that additional tools may be required beyond what is normally 3397 needed to build gcc. 3398 3399 `srcextra' 3400 Generates files in the source directory that do not exist in CVS 3401 but should go into a release tarball. One example is 3402 `gcc/java/parse.c' which is generated from the CVS source file 3403 `gcc/java/parse.y'. 3404 3405 `srcinfo' 3406 `srcman' 3407 Copies the info-formatted and manpage documentation into the source 3408 directory usually for the purpose of generating a release tarball. 3409 3410 `install' 3411 Installs gcc. 3412 3413 `uninstall' 3414 Deletes installed files. 3415 3416 `check' 3417 Run the testsuite. This creates a `testsuite' subdirectory that 3418 has various `.sum' and `.log' files containing the results of the 3419 testing. You can run subsets with, for example, `make check-gcc'. 3420 You can specify specific tests by setting RUNTESTFLAGS to be the 3421 name of the `.exp' file, optionally followed by (for some tests) 3422 an equals and a file wildcard, like: 3423 3424 make check-gcc RUNTESTFLAGS="execute.exp=19980413-*" 3425 3426 Note that running the testsuite may require additional tools be 3427 installed, such as TCL or dejagnu. 3428 3429 The toplevel tree from which you start GCC compilation is not the GCC 3430 directory, but rather a complex Makefile that coordinates the various 3431 steps of the build, including bootstrapping the compiler and using the 3432 new compiler to build target libraries. 3433 3434 When GCC is configured for a native configuration, the default action 3435 for `make' is to do a full three-stage bootstrap. This means that GCC 3436 is built three times--once with the native compiler, once with the 3437 native-built compiler it just built, and once with the compiler it 3438 built the second time. In theory, the last two should produce the same 3439 results, which `make compare' can check. Each stage is configured 3440 separately and compiled into a separate directory, to minimize problems 3441 due to ABI incompatibilities between the native compiler and GCC. 3442 3443 If you do a change, rebuilding will also start from the first stage 3444 and "bubble" up the change through the three stages. Each stage is 3445 taken from its build directory (if it had been built previously), 3446 rebuilt, and copied to its subdirectory. This will allow you to, for 3447 example, continue a bootstrap after fixing a bug which causes the 3448 stage2 build to crash. It does not provide as good coverage of the 3449 compiler as bootstrapping from scratch, but it ensures that the new 3450 code is syntactically correct (e.g., that you did not use GCC extensions 3451 by mistake), and avoids spurious bootstrap comparison failures(1). 3452 3453 Other targets available from the top level include: 3454 3455 `bootstrap-lean' 3456 Like `bootstrap', except that the various stages are removed once 3457 they're no longer needed. This saves disk space. 3458 3459 `bootstrap2' 3460 `bootstrap2-lean' 3461 Performs only the first two stages of bootstrap. Unlike a 3462 three-stage bootstrap, this does not perform a comparison to test 3463 that the compiler is running properly. Note that the disk space 3464 required by a "lean" bootstrap is approximately independent of the 3465 number of stages. 3466 3467 `stageN-bubble (N = 1...4)' 3468 Rebuild all the stages up to N, with the appropriate flags, 3469 "bubbling" the changes as described above. 3470 3471 `all-stageN (N = 1...4)' 3472 Assuming that stage N has already been built, rebuild it with the 3473 appropriate flags. This is rarely needed. 3474 3475 `cleanstrap' 3476 Remove everything (`make clean') and rebuilds (`make bootstrap'). 3477 3478 `compare' 3479 Compares the results of stages 2 and 3. This ensures that the 3480 compiler is running properly, since it should produce the same 3481 object files regardless of how it itself was compiled. 3482 3483 `profiledbootstrap' 3484 Builds a compiler with profiling feedback information. For more 3485 information, see *Note Building with profile feedback: 3486 (gccinstall)Building. 3487 3488 `restrap' 3489 Restart a bootstrap, so that everything that was not built with 3490 the system compiler is rebuilt. 3491 3492 `stageN-start (N = 1...4)' 3493 For each package that is bootstrapped, rename directories so that, 3494 for example, `gcc' points to the stageN GCC, compiled with the 3495 stageN-1 GCC(2). 3496 3497 You will invoke this target if you need to test or debug the 3498 stageN GCC. If you only need to execute GCC (but you need not run 3499 `make' either to rebuild it or to run test suites), you should be 3500 able to work directly in the `stageN-gcc' directory. This makes 3501 it easier to debug multiple stages in parallel. 3502 3503 `stage' 3504 For each package that is bootstrapped, relocate its build directory 3505 to indicate its stage. For example, if the `gcc' directory points 3506 to the stage2 GCC, after invoking this target it will be renamed 3507 to `stage2-gcc'. 3508 3509 3510 If you wish to use non-default GCC flags when compiling the stage2 and 3511 stage3 compilers, set `BOOT_CFLAGS' on the command line when doing 3512 `make'. 3513 3514 Usually, the first stage only builds the languages that the compiler 3515 is written in: typically, C and maybe Ada. If you are debugging a 3516 miscompilation of a different stage2 front-end (for example, of the 3517 Fortran front-end), you may want to have front-ends for other languages 3518 in the first stage as well. To do so, set `STAGE1_LANGUAGES' on the 3519 command line when doing `make'. 3520 3521 For example, in the aforementioned scenario of debugging a Fortran 3522 front-end miscompilation caused by the stage1 compiler, you may need a 3523 command like 3524 3525 make stage2-bubble STAGE1_LANGUAGES=c,fortran 3526 3527 Alternatively, you can use per-language targets to build and test 3528 languages that are not enabled by default in stage1. For example, 3529 `make f951' will build a Fortran compiler even in the stage1 build 3530 directory. 3531 3532 ---------- Footnotes ---------- 3533 3534 (1) Except if the compiler was buggy and miscompiled some of the files 3535 that were not modified. In this case, it's best to use `make restrap'. 3536 3537 (2) Customarily, the system compiler is also termed the `stage0' GCC. 3538 3539 3540 File: gccint.info, Node: Library Files, Next: Headers, Prev: Makefile, Up: gcc Directory 3541 3542 6.3.5 Library Source Files and Headers under the `gcc' Directory 3543 ---------------------------------------------------------------- 3544 3545 FIXME: list here, with explanation, all the C source files and headers 3546 under the `gcc' directory that aren't built into the GCC executable but 3547 rather are part of runtime libraries and object files, such as 3548 `crtstuff.c' and `unwind-dw2.c'. *Note Headers Installed by GCC: 3549 Headers, for more information about the `ginclude' directory. 3550 3551 3552 File: gccint.info, Node: Headers, Next: Documentation, Prev: Library Files, Up: gcc Directory 3553 3554 6.3.6 Headers Installed by GCC 3555 ------------------------------ 3556 3557 In general, GCC expects the system C library to provide most of the 3558 headers to be used with it. However, GCC will fix those headers if 3559 necessary to make them work with GCC, and will install some headers 3560 required of freestanding implementations. These headers are installed 3561 in `LIBSUBDIR/include'. Headers for non-C runtime libraries are also 3562 installed by GCC; these are not documented here. (FIXME: document them 3563 somewhere.) 3564 3565 Several of the headers GCC installs are in the `ginclude' directory. 3566 These headers, `iso646.h', `stdarg.h', `stdbool.h', and `stddef.h', are 3567 installed in `LIBSUBDIR/include', unless the target Makefile fragment 3568 (*note Target Fragment::) overrides this by setting `USER_H'. 3569 3570 In addition to these headers and those generated by fixing system 3571 headers to work with GCC, some other headers may also be installed in 3572 `LIBSUBDIR/include'. `config.gcc' may set `extra_headers'; this 3573 specifies additional headers under `config' to be installed on some 3574 systems. 3575 3576 GCC installs its own version of `<float.h>', from `ginclude/float.h'. 3577 This is done to cope with command-line options that change the 3578 representation of floating point numbers. 3579 3580 GCC also installs its own version of `<limits.h>'; this is generated 3581 from `glimits.h', together with `limitx.h' and `limity.h' if the system 3582 also has its own version of `<limits.h>'. (GCC provides its own header 3583 because it is required of ISO C freestanding implementations, but needs 3584 to include the system header from its own header as well because other 3585 standards such as POSIX specify additional values to be defined in 3586 `<limits.h>'.) The system's `<limits.h>' header is used via 3587 `LIBSUBDIR/include/syslimits.h', which is copied from `gsyslimits.h' if 3588 it does not need fixing to work with GCC; if it needs fixing, 3589 `syslimits.h' is the fixed copy. 3590 3591 GCC can also install `<tgmath.h>'. It will do this when `config.gcc' 3592 sets `use_gcc_tgmath' to `yes'. 3593 3594 3595 File: gccint.info, Node: Documentation, Next: Front End, Prev: Headers, Up: gcc Directory 3596 3597 6.3.7 Building Documentation 3598 ---------------------------- 3599 3600 The main GCC documentation is in the form of manuals in Texinfo format. 3601 These are installed in Info format; DVI versions may be generated by 3602 `make dvi', PDF versions by `make pdf', and HTML versions by `make 3603 html'. In addition, some man pages are generated from the Texinfo 3604 manuals, there are some other text files with miscellaneous 3605 documentation, and runtime libraries have their own documentation 3606 outside the `gcc' directory. FIXME: document the documentation for 3607 runtime libraries somewhere. 3608 3609 * Menu: 3610 3611 * Texinfo Manuals:: GCC manuals in Texinfo format. 3612 * Man Page Generation:: Generating man pages from Texinfo manuals. 3613 * Miscellaneous Docs:: Miscellaneous text files with documentation. 3614 3615 3616 File: gccint.info, Node: Texinfo Manuals, Next: Man Page Generation, Up: Documentation 3617 3618 6.3.7.1 Texinfo Manuals 3619 ....................... 3620 3621 The manuals for GCC as a whole, and the C and C++ front ends, are in 3622 files `doc/*.texi'. Other front ends have their own manuals in files 3623 `LANGUAGE/*.texi'. Common files `doc/include/*.texi' are provided 3624 which may be included in multiple manuals; the following files are in 3625 `doc/include': 3626 3627 `fdl.texi' 3628 The GNU Free Documentation License. 3629 3630 `funding.texi' 3631 The section "Funding Free Software". 3632 3633 `gcc-common.texi' 3634 Common definitions for manuals. 3635 3636 `gpl.texi' 3637 `gpl_v3.texi' 3638 The GNU General Public License. 3639 3640 `texinfo.tex' 3641 A copy of `texinfo.tex' known to work with the GCC manuals. 3642 3643 DVI-formatted manuals are generated by `make dvi', which uses 3644 `texi2dvi' (via the Makefile macro `$(TEXI2DVI)'). PDF-formatted 3645 manuals are generated by `make pdf', which uses `texi2pdf' (via the 3646 Makefile macro `$(TEXI2PDF)'). HTML formatted manuals are generated by 3647 `make html'. Info manuals are generated by `make info' (which is run 3648 as part of a bootstrap); this generates the manuals in the source 3649 directory, using `makeinfo' via the Makefile macro `$(MAKEINFO)', and 3650 they are included in release distributions. 3651 3652 Manuals are also provided on the GCC web site, in both HTML and 3653 PostScript forms. This is done via the script 3654 `maintainer-scripts/update_web_docs'. Each manual to be provided 3655 online must be listed in the definition of `MANUALS' in that file; a 3656 file `NAME.texi' must only appear once in the source tree, and the 3657 output manual must have the same name as the source file. (However, 3658 other Texinfo files, included in manuals but not themselves the root 3659 files of manuals, may have names that appear more than once in the 3660 source tree.) The manual file `NAME.texi' should only include other 3661 files in its own directory or in `doc/include'. HTML manuals will be 3662 generated by `makeinfo --html', PostScript manuals by `texi2dvi' and 3663 `dvips', and PDF manuals by `texi2pdf'. All Texinfo files that are 3664 parts of manuals must be checked into SVN, even if they are generated 3665 files, for the generation of online manuals to work. 3666 3667 The installation manual, `doc/install.texi', is also provided on the 3668 GCC web site. The HTML version is generated by the script 3669 `doc/install.texi2html'. 3670 3671 3672 File: gccint.info, Node: Man Page Generation, Next: Miscellaneous Docs, Prev: Texinfo Manuals, Up: Documentation 3673 3674 6.3.7.2 Man Page Generation 3675 ........................... 3676 3677 Because of user demand, in addition to full Texinfo manuals, man pages 3678 are provided which contain extracts from those manuals. These man 3679 pages are generated from the Texinfo manuals using 3680 `contrib/texi2pod.pl' and `pod2man'. (The man page for `g++', 3681 `cp/g++.1', just contains a `.so' reference to `gcc.1', but all the 3682 other man pages are generated from Texinfo manuals.) 3683 3684 Because many systems may not have the necessary tools installed to 3685 generate the man pages, they are only generated if the `configure' 3686 script detects that recent enough tools are installed, and the 3687 Makefiles allow generating man pages to fail without aborting the 3688 build. Man pages are also included in release distributions. They are 3689 generated in the source directory. 3690 3691 Magic comments in Texinfo files starting `@c man' control what parts 3692 of a Texinfo file go into a man page. Only a subset of Texinfo is 3693 supported by `texi2pod.pl', and it may be necessary to add support for 3694 more Texinfo features to this script when generating new man pages. To 3695 improve the man page output, some special Texinfo macros are provided 3696 in `doc/include/gcc-common.texi' which `texi2pod.pl' understands: 3697 3698 `@gcctabopt' 3699 Use in the form `@table @gcctabopt' for tables of options, where 3700 for printed output the effect of `@code' is better than that of 3701 `@option' but for man page output a different effect is wanted. 3702 3703 `@gccoptlist' 3704 Use for summary lists of options in manuals. 3705 3706 `@gol' 3707 Use at the end of each line inside `@gccoptlist'. This is 3708 necessary to avoid problems with differences in how the 3709 `@gccoptlist' macro is handled by different Texinfo formatters. 3710 3711 FIXME: describe the `texi2pod.pl' input language and magic comments in 3712 more detail. 3713 3714 3715 File: gccint.info, Node: Miscellaneous Docs, Prev: Man Page Generation, Up: Documentation 3716 3717 6.3.7.3 Miscellaneous Documentation 3718 ................................... 3719 3720 In addition to the formal documentation that is installed by GCC, there 3721 are several other text files with miscellaneous documentation: 3722 3723 `ABOUT-GCC-NLS' 3724 Notes on GCC's Native Language Support. FIXME: this should be 3725 part of this manual rather than a separate file. 3726 3727 `ABOUT-NLS' 3728 Notes on the Free Translation Project. 3729 3730 `COPYING' 3731 The GNU General Public License. 3732 3733 `COPYING.LIB' 3734 The GNU Lesser General Public License. 3735 3736 `*ChangeLog*' 3737 `*/ChangeLog*' 3738 Change log files for various parts of GCC. 3739 3740 `LANGUAGES' 3741 Details of a few changes to the GCC front-end interface. FIXME: 3742 the information in this file should be part of general 3743 documentation of the front-end interface in this manual. 3744 3745 `ONEWS' 3746 Information about new features in old versions of GCC. (For recent 3747 versions, the information is on the GCC web site.) 3748 3749 `README.Portability' 3750 Information about portability issues when writing code in GCC. 3751 FIXME: why isn't this part of this manual or of the GCC Coding 3752 Conventions? 3753 3754 FIXME: document such files in subdirectories, at least `config', `cp', 3755 `objc', `testsuite'. 3756 3757 3758 File: gccint.info, Node: Front End, Next: Back End, Prev: Documentation, Up: gcc Directory 3759 3760 6.3.8 Anatomy of a Language Front End 3761 ------------------------------------- 3762 3763 A front end for a language in GCC has the following parts: 3764 3765 * A directory `LANGUAGE' under `gcc' containing source files for 3766 that front end. *Note The Front End `LANGUAGE' Directory: Front 3767 End Directory, for details. 3768 3769 * A mention of the language in the list of supported languages in 3770 `gcc/doc/install.texi'. 3771 3772 * A mention of the name under which the language's runtime library is 3773 recognized by `--enable-shared=PACKAGE' in the documentation of 3774 that option in `gcc/doc/install.texi'. 3775 3776 * A mention of any special prerequisites for building the front end 3777 in the documentation of prerequisites in `gcc/doc/install.texi'. 3778 3779 * Details of contributors to that front end in 3780 `gcc/doc/contrib.texi'. If the details are in that front end's 3781 own manual then there should be a link to that manual's list in 3782 `contrib.texi'. 3783 3784 * Information about support for that language in 3785 `gcc/doc/frontends.texi'. 3786 3787 * Information about standards for that language, and the front end's 3788 support for them, in `gcc/doc/standards.texi'. This may be a link 3789 to such information in the front end's own manual. 3790 3791 * Details of source file suffixes for that language and `-x LANG' 3792 options supported, in `gcc/doc/invoke.texi'. 3793 3794 * Entries in `default_compilers' in `gcc.c' for source file suffixes 3795 for that language. 3796 3797 * Preferably testsuites, which may be under `gcc/testsuite' or 3798 runtime library directories. FIXME: document somewhere how to 3799 write testsuite harnesses. 3800 3801 * Probably a runtime library for the language, outside the `gcc' 3802 directory. FIXME: document this further. 3803 3804 * Details of the directories of any runtime libraries in 3805 `gcc/doc/sourcebuild.texi'. 3806 3807 If the front end is added to the official GCC source repository, the 3808 following are also necessary: 3809 3810 * At least one Bugzilla component for bugs in that front end and 3811 runtime libraries. This category needs to be mentioned in 3812 `gcc/gccbug.in', as well as being added to the Bugzilla database. 3813 3814 * Normally, one or more maintainers of that front end listed in 3815 `MAINTAINERS'. 3816 3817 * Mentions on the GCC web site in `index.html' and `frontends.html', 3818 with any relevant links on `readings.html'. (Front ends that are 3819 not an official part of GCC may also be listed on 3820 `frontends.html', with relevant links.) 3821 3822 * A news item on `index.html', and possibly an announcement on the 3823 <gcc-announce (a] gcc.gnu.org> mailing list. 3824 3825 * The front end's manuals should be mentioned in 3826 `maintainer-scripts/update_web_docs' (*note Texinfo Manuals::) and 3827 the online manuals should be linked to from 3828 `onlinedocs/index.html'. 3829 3830 * Any old releases or CVS repositories of the front end, before its 3831 inclusion in GCC, should be made available on the GCC FTP site 3832 `ftp://gcc.gnu.org/pub/gcc/old-releases/'. 3833 3834 * The release and snapshot script `maintainer-scripts/gcc_release' 3835 should be updated to generate appropriate tarballs for this front 3836 end. The associated `maintainer-scripts/snapshot-README' and 3837 `maintainer-scripts/snapshot-index.html' files should be updated 3838 to list the tarballs and diffs for this front end. 3839 3840 * If this front end includes its own version files that include the 3841 current date, `maintainer-scripts/update_version' should be 3842 updated accordingly. 3843 3844 * Menu: 3845 3846 * Front End Directory:: The front end `LANGUAGE' directory. 3847 * Front End Config:: The front end `config-lang.in' file. 3848 3849 3850 File: gccint.info, Node: Front End Directory, Next: Front End Config, Up: Front End 3851 3852 6.3.8.1 The Front End `LANGUAGE' Directory 3853 .......................................... 3854 3855 A front end `LANGUAGE' directory contains the source files of that 3856 front end (but not of any runtime libraries, which should be outside 3857 the `gcc' directory). This includes documentation, and possibly some 3858 subsidiary programs build alongside the front end. Certain files are 3859 special and other parts of the compiler depend on their names: 3860 3861 `config-lang.in' 3862 This file is required in all language subdirectories. *Note The 3863 Front End `config-lang.in' File: Front End Config, for details of 3864 its contents 3865 3866 `Make-lang.in' 3867 This file is required in all language subdirectories. It contains 3868 targets `LANG.HOOK' (where `LANG' is the setting of `language' in 3869 `config-lang.in') for the following values of `HOOK', and any 3870 other Makefile rules required to build those targets (which may if 3871 necessary use other Makefiles specified in `outputs' in 3872 `config-lang.in', although this is deprecated). It also adds any 3873 testsuite targets that can use the standard rule in 3874 `gcc/Makefile.in' to the variable `lang_checks'. 3875 3876 `all.cross' 3877 `start.encap' 3878 `rest.encap' 3879 FIXME: exactly what goes in each of these targets? 3880 3881 `tags' 3882 Build an `etags' `TAGS' file in the language subdirectory in 3883 the source tree. 3884 3885 `info' 3886 Build info documentation for the front end, in the build 3887 directory. This target is only called by `make bootstrap' if 3888 a suitable version of `makeinfo' is available, so does not 3889 need to check for this, and should fail if an error occurs. 3890 3891 `dvi' 3892 Build DVI documentation for the front end, in the build 3893 directory. This should be done using `$(TEXI2DVI)', with 3894 appropriate `-I' arguments pointing to directories of 3895 included files. 3896 3897 `pdf' 3898 Build PDF documentation for the front end, in the build 3899 directory. This should be done using `$(TEXI2PDF)', with 3900 appropriate `-I' arguments pointing to directories of 3901 included files. 3902 3903 `html' 3904 Build HTML documentation for the front end, in the build 3905 directory. 3906 3907 `man' 3908 Build generated man pages for the front end from Texinfo 3909 manuals (*note Man Page Generation::), in the build 3910 directory. This target is only called if the necessary tools 3911 are available, but should ignore errors so as not to stop the 3912 build if errors occur; man pages are optional and the tools 3913 involved may be installed in a broken way. 3914 3915 `install-common' 3916 Install everything that is part of the front end, apart from 3917 the compiler executables listed in `compilers' in 3918 `config-lang.in'. 3919 3920 `install-info' 3921 Install info documentation for the front end, if it is 3922 present in the source directory. This target should have 3923 dependencies on info files that should be installed. 3924 3925 `install-man' 3926 Install man pages for the front end. This target should 3927 ignore errors. 3928 3929 `install-plugin' 3930 Install headers needed for plugins. 3931 3932 `srcextra' 3933 Copies its dependencies into the source directory. This 3934 generally should be used for generated files such as Bison 3935 output files which are not present in CVS, but should be 3936 included in any release tarballs. This target will be 3937 executed during a bootstrap if 3938 `--enable-generated-files-in-srcdir' was specified as a 3939 `configure' option. 3940 3941 `srcinfo' 3942 `srcman' 3943 Copies its dependencies into the source directory. These 3944 targets will be executed during a bootstrap if 3945 `--enable-generated-files-in-srcdir' was specified as a 3946 `configure' option. 3947 3948 `uninstall' 3949 Uninstall files installed by installing the compiler. This is 3950 currently documented not to be supported, so the hook need 3951 not do anything. 3952 3953 `mostlyclean' 3954 `clean' 3955 `distclean' 3956 `maintainer-clean' 3957 The language parts of the standard GNU `*clean' targets. 3958 *Note Standard Targets for Users: (standards)Standard 3959 Targets, for details of the standard targets. For GCC, 3960 `maintainer-clean' should delete all generated files in the 3961 source directory that are not checked into CVS, but should 3962 not delete anything checked into CVS. 3963 3964 `Make-lang.in' must also define a variable `LANG_OBJS' to a list 3965 of host object files that are used by that language. 3966 3967 `lang.opt' 3968 This file registers the set of switches that the front end accepts 3969 on the command line, and their `--help' text. *Note Options::. 3970 3971 `lang-specs.h' 3972 This file provides entries for `default_compilers' in `gcc.c' 3973 which override the default of giving an error that a compiler for 3974 that language is not installed. 3975 3976 `LANGUAGE-tree.def' 3977 This file, which need not exist, defines any language-specific tree 3978 codes. 3979 3980 3981 File: gccint.info, Node: Front End Config, Prev: Front End Directory, Up: Front End 3982 3983 6.3.8.2 The Front End `config-lang.in' File 3984 ........................................... 3985 3986 Each language subdirectory contains a `config-lang.in' file. In 3987 addition the main directory contains `c-config-lang.in', which contains 3988 limited information for the C language. This file is a shell script 3989 that may define some variables describing the language: 3990 3991 `language' 3992 This definition must be present, and gives the name of the language 3993 for some purposes such as arguments to `--enable-languages'. 3994 3995 `lang_requires' 3996 If defined, this variable lists (space-separated) language front 3997 ends other than C that this front end requires to be enabled (with 3998 the names given being their `language' settings). For example, the 3999 Java front end depends on the C++ front end, so sets 4000 `lang_requires=c++'. 4001 4002 `subdir_requires' 4003 If defined, this variable lists (space-separated) front end 4004 directories other than C that this front end requires to be 4005 present. For example, the Objective-C++ front end uses source 4006 files from the C++ and Objective-C front ends, so sets 4007 `subdir_requires="cp objc"'. 4008 4009 `target_libs' 4010 If defined, this variable lists (space-separated) targets in the 4011 top level `Makefile' to build the runtime libraries for this 4012 language, such as `target-libobjc'. 4013 4014 `lang_dirs' 4015 If defined, this variable lists (space-separated) top level 4016 directories (parallel to `gcc'), apart from the runtime libraries, 4017 that should not be configured if this front end is not built. 4018 4019 `build_by_default' 4020 If defined to `no', this language front end is not built unless 4021 enabled in a `--enable-languages' argument. Otherwise, front ends 4022 are built by default, subject to any special logic in 4023 `configure.ac' (as is present to disable the Ada front end if the 4024 Ada compiler is not already installed). 4025 4026 `boot_language' 4027 If defined to `yes', this front end is built in stage 1 of the 4028 bootstrap. This is only relevant to front ends written in their 4029 own languages. 4030 4031 `compilers' 4032 If defined, a space-separated list of compiler executables that 4033 will be run by the driver. The names here will each end with 4034 `\$(exeext)'. 4035 4036 `outputs' 4037 If defined, a space-separated list of files that should be 4038 generated by `configure' substituting values in them. This 4039 mechanism can be used to create a file `LANGUAGE/Makefile' from 4040 `LANGUAGE/Makefile.in', but this is deprecated, building 4041 everything from the single `gcc/Makefile' is preferred. 4042 4043 `gtfiles' 4044 If defined, a space-separated list of files that should be scanned 4045 by gengtype.c to generate the garbage collection tables and 4046 routines for this language. This excludes the files that are 4047 common to all front ends. *Note Type Information::. 4048 4049 4050 4051 File: gccint.info, Node: Back End, Prev: Front End, Up: gcc Directory 4052 4053 6.3.9 Anatomy of a Target Back End 4054 ---------------------------------- 4055 4056 A back end for a target architecture in GCC has the following parts: 4057 4058 * A directory `MACHINE' under `gcc/config', containing a machine 4059 description `MACHINE.md' file (*note Machine Descriptions: Machine 4060 Desc.), header files `MACHINE.h' and `MACHINE-protos.h' and a 4061 source file `MACHINE.c' (*note Target Description Macros and 4062 Functions: Target Macros.), possibly a target Makefile fragment 4063 `t-MACHINE' (*note The Target Makefile Fragment: Target 4064 Fragment.), and maybe some other files. The names of these files 4065 may be changed from the defaults given by explicit specifications 4066 in `config.gcc'. 4067 4068 * If necessary, a file `MACHINE-modes.def' in the `MACHINE' 4069 directory, containing additional machine modes to represent 4070 condition codes. *Note Condition Code::, for further details. 4071 4072 * An optional `MACHINE.opt' file in the `MACHINE' directory, 4073 containing a list of target-specific options. You can also add 4074 other option files using the `extra_options' variable in 4075 `config.gcc'. *Note Options::. 4076 4077 * Entries in `config.gcc' (*note The `config.gcc' File: System 4078 Config.) for the systems with this target architecture. 4079 4080 * Documentation in `gcc/doc/invoke.texi' for any command-line 4081 options supported by this target (*note Run-time Target 4082 Specification: Run-time Target.). This means both entries in the 4083 summary table of options and details of the individual options. 4084 4085 * Documentation in `gcc/doc/extend.texi' for any target-specific 4086 attributes supported (*note Defining target-specific uses of 4087 `__attribute__': Target Attributes.), including where the same 4088 attribute is already supported on some targets, which are 4089 enumerated in the manual. 4090 4091 * Documentation in `gcc/doc/extend.texi' for any target-specific 4092 pragmas supported. 4093 4094 * Documentation in `gcc/doc/extend.texi' of any target-specific 4095 built-in functions supported. 4096 4097 * Documentation in `gcc/doc/extend.texi' of any target-specific 4098 format checking styles supported. 4099 4100 * Documentation in `gcc/doc/md.texi' of any target-specific 4101 constraint letters (*note Constraints for Particular Machines: 4102 Machine Constraints.). 4103 4104 * A note in `gcc/doc/contrib.texi' under the person or people who 4105 contributed the target support. 4106 4107 * Entries in `gcc/doc/install.texi' for all target triplets 4108 supported with this target architecture, giving details of any 4109 special notes about installation for this target, or saying that 4110 there are no special notes if there are none. 4111 4112 * Possibly other support outside the `gcc' directory for runtime 4113 libraries. FIXME: reference docs for this. The libstdc++ porting 4114 manual needs to be installed as info for this to work, or to be a 4115 chapter of this manual. 4116 4117 If the back end is added to the official GCC source repository, the 4118 following are also necessary: 4119 4120 * An entry for the target architecture in `readings.html' on the GCC 4121 web site, with any relevant links. 4122 4123 * Details of the properties of the back end and target architecture 4124 in `backends.html' on the GCC web site. 4125 4126 * A news item about the contribution of support for that target 4127 architecture, in `index.html' on the GCC web site. 4128 4129 * Normally, one or more maintainers of that target listed in 4130 `MAINTAINERS'. Some existing architectures may be unmaintained, 4131 but it would be unusual to add support for a target that does not 4132 have a maintainer when support is added. 4133 4134 4135 File: gccint.info, Node: Testsuites, Prev: gcc Directory, Up: Source Tree 4136 4137 6.4 Testsuites 4138 ============== 4139 4140 GCC contains several testsuites to help maintain compiler quality. 4141 Most of the runtime libraries and language front ends in GCC have 4142 testsuites. Currently only the C language testsuites are documented 4143 here; FIXME: document the others. 4144 4145 * Menu: 4146 4147 * Test Idioms:: Idioms used in testsuite code. 4148 * Test Directives:: Directives used within DejaGnu tests. 4149 * Ada Tests:: The Ada language testsuites. 4150 * C Tests:: The C language testsuites. 4151 * libgcj Tests:: The Java library testsuites. 4152 * gcov Testing:: Support for testing gcov. 4153 * profopt Testing:: Support for testing profile-directed optimizations. 4154 * compat Testing:: Support for testing binary compatibility. 4155 * Torture Tests:: Support for torture testing using multiple options. 4156 4157 4158 File: gccint.info, Node: Test Idioms, Next: Test Directives, Up: Testsuites 4159 4160 6.4.1 Idioms Used in Testsuite Code 4161 ----------------------------------- 4162 4163 In general, C testcases have a trailing `-N.c', starting with `-1.c', 4164 in case other testcases with similar names are added later. If the 4165 test is a test of some well-defined feature, it should have a name 4166 referring to that feature such as `FEATURE-1.c'. If it does not test a 4167 well-defined feature but just happens to exercise a bug somewhere in 4168 the compiler, and a bug report has been filed for this bug in the GCC 4169 bug database, `prBUG-NUMBER-1.c' is the appropriate form of name. 4170 Otherwise (for miscellaneous bugs not filed in the GCC bug database), 4171 and previously more generally, test cases are named after the date on 4172 which they were added. This allows people to tell at a glance whether 4173 a test failure is because of a recently found bug that has not yet been 4174 fixed, or whether it may be a regression, but does not give any other 4175 information about the bug or where discussion of it may be found. Some 4176 other language testsuites follow similar conventions. 4177 4178 In the `gcc.dg' testsuite, it is often necessary to test that an error 4179 is indeed a hard error and not just a warning--for example, where it is 4180 a constraint violation in the C standard, which must become an error 4181 with `-pedantic-errors'. The following idiom, where the first line 4182 shown is line LINE of the file and the line that generates the error, 4183 is used for this: 4184 4185 /* { dg-bogus "warning" "warning in place of error" } */ 4186 /* { dg-error "REGEXP" "MESSAGE" { target *-*-* } LINE } */ 4187 4188 It may be necessary to check that an expression is an integer constant 4189 expression and has a certain value. To check that `E' has value `V', 4190 an idiom similar to the following is used: 4191 4192 char x[((E) == (V) ? 1 : -1)]; 4193 4194 In `gcc.dg' tests, `__typeof__' is sometimes used to make assertions 4195 about the types of expressions. See, for example, 4196 `gcc.dg/c99-condexpr-1.c'. The more subtle uses depend on the exact 4197 rules for the types of conditional expressions in the C standard; see, 4198 for example, `gcc.dg/c99-intconst-1.c'. 4199 4200 It is useful to be able to test that optimizations are being made 4201 properly. This cannot be done in all cases, but it can be done where 4202 the optimization will lead to code being optimized away (for example, 4203 where flow analysis or alias analysis should show that certain code 4204 cannot be called) or to functions not being called because they have 4205 been expanded as built-in functions. Such tests go in 4206 `gcc.c-torture/execute'. Where code should be optimized away, a call 4207 to a nonexistent function such as `link_failure ()' may be inserted; a 4208 definition 4209 4210 #ifndef __OPTIMIZE__ 4211 void 4212 link_failure (void) 4213 { 4214 abort (); 4215 } 4216 #endif 4217 4218 will also be needed so that linking still succeeds when the test is run 4219 without optimization. When all calls to a built-in function should 4220 have been optimized and no calls to the non-built-in version of the 4221 function should remain, that function may be defined as `static' to 4222 call `abort ()' (although redeclaring a function as static may not work 4223 on all targets). 4224 4225 All testcases must be portable. Target-specific testcases must have 4226 appropriate code to avoid causing failures on unsupported systems; 4227 unfortunately, the mechanisms for this differ by directory. 4228 4229 FIXME: discuss non-C testsuites here. 4230 4231 4232 File: gccint.info, Node: Test Directives, Next: Ada Tests, Prev: Test Idioms, Up: Testsuites 4233 4234 6.4.2 Directives used within DejaGnu tests 4235 ------------------------------------------ 4236 4237 Test directives appear within comments in a test source file and begin 4238 with `dg-'. Some of these are defined within DejaGnu and others are 4239 local to the GCC testsuite. 4240 4241 The order in which test directives appear in a test can be important: 4242 directives local to GCC sometimes override information used by the 4243 DejaGnu directives, which know nothing about the GCC directives, so the 4244 DejaGnu directives must precede GCC directives. 4245 4246 Several test directives include selectors which are usually preceded by 4247 the keyword `target' or `xfail'. A selector is: one or more target 4248 triplets, possibly including wildcard characters; a single 4249 effective-target keyword; or a logical expression. Depending on the 4250 context, the selector specifies whether a test is skipped and reported 4251 as unsupported or is expected to fail. Use `*-*-*' to match any target. 4252 Effective-target keywords are defined in `target-supports.exp' in the 4253 GCC testsuite. 4254 4255 A selector expression appears within curly braces and uses a single 4256 logical operator: one of `!', `&&', or `||'. An operand is another 4257 selector expression, an effective-target keyword, a single target 4258 triplet, or a list of target triplets within quotes or curly braces. 4259 For example: 4260 4261 { target { ! "hppa*-*-* ia64*-*-*" } } 4262 { target { powerpc*-*-* && lp64 } } 4263 { xfail { lp64 || vect_no_align } } 4264 4265 `{ dg-do DO-WHAT-KEYWORD [{ target/xfail SELECTOR }] }' 4266 DO-WHAT-KEYWORD specifies how the test is compiled and whether it 4267 is executed. It is one of: 4268 4269 `preprocess' 4270 Compile with `-E' to run only the preprocessor. 4271 4272 `compile' 4273 Compile with `-S' to produce an assembly code file. 4274 4275 `assemble' 4276 Compile with `-c' to produce a relocatable object file. 4277 4278 `link' 4279 Compile, assemble, and link to produce an executable file. 4280 4281 `run' 4282 Produce and run an executable file, which is expected to 4283 return an exit code of 0. 4284 4285 The default is `compile'. That can be overridden for a set of 4286 tests by redefining `dg-do-what-default' within the `.exp' file 4287 for those tests. 4288 4289 If the directive includes the optional `{ target SELECTOR }' then 4290 the test is skipped unless the target system is included in the 4291 list of target triplets or matches the effective-target keyword. 4292 4293 If `do-what-keyword' is `run' and the directive includes the 4294 optional `{ xfail SELECTOR }' and the selector is met then the 4295 test is expected to fail. The `xfail' clause is ignored for other 4296 values of `do-what-keyword'; those tests can use directive 4297 `dg-xfail-if'. 4298 4299 `{ dg-options OPTIONS [{ target SELECTOR }] }' 4300 This DejaGnu directive provides a list of compiler options, to be 4301 used if the target system matches SELECTOR, that replace the 4302 default options used for this set of tests. 4303 4304 `{ dg-add-options FEATURE ... }' 4305 Add any compiler options that are needed to access certain 4306 features. This directive does nothing on targets that enable the 4307 features by default, or that don't provide them at all. It must 4308 come after all `dg-options' directives. 4309 4310 The supported values of FEATURE are: 4311 `c99_runtime' 4312 The target's C99 runtime (both headers and libraries). 4313 4314 `mips16_attribute' 4315 `mips16' function attributes. Only MIPS targets support this 4316 feature, and only then in certain modes. 4317 4318 `{ dg-timeout N [{target SELECTOR }] }' 4319 Set the time limit for the compilation and for the execution of 4320 the test to the specified number of seconds. 4321 4322 `{ dg-timeout-factor X [{ target SELECTOR }] }' 4323 Multiply the normal time limit for compilation and execution of 4324 the test by the specified floating-point factor. The normal 4325 timeout limit, in seconds, is found by searching the following in 4326 order: 4327 4328 * the value defined by an earlier `dg-timeout' directive in the 4329 test 4330 4331 * variable TOOL_TIMEOUT defined by the set of tests 4332 4333 * GCC,TIMEOUT set in the target board 4334 4335 * 300 4336 4337 `{ dg-skip-if COMMENT { SELECTOR } { INCLUDE-OPTS } { EXCLUDE-OPTS } }' 4338 Skip the test if the test system is included in SELECTOR and if 4339 each of the options in INCLUDE-OPTS is in the set of options with 4340 which the test would be compiled and if none of the options in 4341 EXCLUDE-OPTS is in the set of options with which the test would be 4342 compiled. 4343 4344 Use `"*"' for an empty INCLUDE-OPTS list and `""' for an empty 4345 EXCLUDE-OPTS list. 4346 4347 `{ dg-xfail-if COMMENT { SELECTOR } { INCLUDE-OPTS } { EXCLUDE-OPTS } }' 4348 Expect the test to fail if the conditions (which are the same as 4349 for `dg-skip-if') are met. This does not affect the execute step. 4350 4351 `{ dg-xfail-run-if COMMENT { SELECTOR } { INCLUDE-OPTS } { EXCLUDE-OPTS } }' 4352 Expect the execute step of a test to fail if the conditions (which 4353 are the same as for `dg-skip-if') and `dg-xfail-if') are met. 4354 4355 `{ dg-require-SUPPORT args }' 4356 Skip the test if the target does not provide the required support; 4357 see `gcc-dg.exp' in the GCC testsuite for the actual directives. 4358 These directives must appear after any `dg-do' directive in the 4359 test and before any `dg-additional-sources' directive. They 4360 require at least one argument, which can be an empty string if the 4361 specific procedure does not examine the argument. 4362 4363 `{ dg-require-effective-target KEYWORD }' 4364 Skip the test if the test target, including current multilib flags, 4365 is not covered by the effective-target keyword. This directive 4366 must appear after any `dg-do' directive in the test and before any 4367 `dg-additional-sources' directive. 4368 4369 `{ dg-shouldfail COMMENT { SELECTOR } { INCLUDE-OPTS } { EXCLUDE-OPTS } }' 4370 Expect the test executable to return a nonzero exit status if the 4371 conditions (which are the same as for `dg-skip-if') are met. 4372 4373 `{ dg-error REGEXP [COMMENT [{ target/xfail SELECTOR } [LINE] }]] }' 4374 This DejaGnu directive appears on a source line that is expected 4375 to get an error message, or else specifies the source line 4376 associated with the message. If there is no message for that line 4377 or if the text of that message is not matched by REGEXP then the 4378 check fails and COMMENT is included in the `FAIL' message. The 4379 check does not look for the string `"error"' unless it is part of 4380 REGEXP. 4381 4382 `{ dg-warning REGEXP [COMMENT [{ target/xfail SELECTOR } [LINE] }]] }' 4383 This DejaGnu directive appears on a source line that is expected 4384 to get a warning message, or else specifies the source line 4385 associated with the message. If there is no message for that line 4386 or if the text of that message is not matched by REGEXP then the 4387 check fails and COMMENT is included in the `FAIL' message. The 4388 check does not look for the string `"warning"' unless it is part 4389 of REGEXP. 4390 4391 `{ dg-message REGEXP [COMMENT [{ target/xfail SELECTOR } [LINE] }]] }' 4392 The line is expected to get a message other than an error or 4393 warning. If there is no message for that line or if the text of 4394 that message is not matched by REGEXP then the check fails and 4395 COMMENT is included in the `FAIL' message. 4396 4397 `{ dg-bogus REGEXP [COMMENT [{ target/xfail SELECTOR } [LINE] }]] }' 4398 This DejaGnu directive appears on a source line that should not 4399 get a message matching REGEXP, or else specifies the source line 4400 associated with the bogus message. It is usually used with `xfail' 4401 to indicate that the message is a known problem for a particular 4402 set of targets. 4403 4404 `{ dg-excess-errors COMMENT [{ target/xfail SELECTOR }] }' 4405 This DejaGnu directive indicates that the test is expected to fail 4406 due to compiler messages that are not handled by `dg-error', 4407 `dg-warning' or `dg-bogus'. For this directive `xfail' has the 4408 same effect as `target'. 4409 4410 `{ dg-output REGEXP [{ target/xfail SELECTOR }] }' 4411 This DejaGnu directive compares REGEXP to the combined output that 4412 the test executable writes to `stdout' and `stderr'. 4413 4414 `{ dg-prune-output REGEXP }' 4415 Prune messages matching REGEXP from test output. 4416 4417 `{ dg-additional-files "FILELIST" }' 4418 Specify additional files, other than source files, that must be 4419 copied to the system where the compiler runs. 4420 4421 `{ dg-additional-sources "FILELIST" }' 4422 Specify additional source files to appear in the compile line 4423 following the main test file. 4424 4425 `{ dg-final { LOCAL-DIRECTIVE } }' 4426 This DejaGnu directive is placed within a comment anywhere in the 4427 source file and is processed after the test has been compiled and 4428 run. Multiple `dg-final' commands are processed in the order in 4429 which they appear in the source file. 4430 4431 The GCC testsuite defines the following directives to be used 4432 within `dg-final'. 4433 4434 `cleanup-coverage-files' 4435 Removes coverage data files generated for this test. 4436 4437 `cleanup-repo-files' 4438 Removes files generated for this test for `-frepo'. 4439 4440 `cleanup-rtl-dump SUFFIX' 4441 Removes RTL dump files generated for this test. 4442 4443 `cleanup-tree-dump SUFFIX' 4444 Removes tree dump files matching SUFFIX which were generated 4445 for this test. 4446 4447 `cleanup-saved-temps' 4448 Removes files for the current test which were kept for 4449 `--save-temps'. 4450 4451 `scan-file FILENAME REGEXP [{ target/xfail SELECTOR }]' 4452 Passes if REGEXP matches text in FILENAME. 4453 4454 `scan-file-not FILENAME REGEXP [{ target/xfail SELECTOR }]' 4455 Passes if REGEXP does not match text in FILENAME. 4456 4457 `scan-hidden SYMBOL [{ target/xfail SELECTOR }]' 4458 Passes if SYMBOL is defined as a hidden symbol in the test's 4459 assembly output. 4460 4461 `scan-not-hidden SYMBOL [{ target/xfail SELECTOR }]' 4462 Passes if SYMBOL is not defined as a hidden symbol in the 4463 test's assembly output. 4464 4465 `scan-assembler-times REGEX NUM [{ target/xfail SELECTOR }]' 4466 Passes if REGEX is matched exactly NUM times in the test's 4467 assembler output. 4468 4469 `scan-assembler REGEX [{ target/xfail SELECTOR }]' 4470 Passes if REGEX matches text in the test's assembler output. 4471 4472 `scan-assembler-not REGEX [{ target/xfail SELECTOR }]' 4473 Passes if REGEX does not match text in the test's assembler 4474 output. 4475 4476 `scan-assembler-dem REGEX [{ target/xfail SELECTOR }]' 4477 Passes if REGEX matches text in the test's demangled 4478 assembler output. 4479 4480 `scan-assembler-dem-not REGEX [{ target/xfail SELECTOR }]' 4481 Passes if REGEX does not match text in the test's demangled 4482 assembler output. 4483 4484 `scan-tree-dump-times REGEX NUM SUFFIX [{ target/xfail SELECTOR }]' 4485 Passes if REGEX is found exactly NUM times in the dump file 4486 with suffix SUFFIX. 4487 4488 `scan-tree-dump REGEX SUFFIX [{ target/xfail SELECTOR }]' 4489 Passes if REGEX matches text in the dump file with suffix 4490 SUFFIX. 4491 4492 `scan-tree-dump-not REGEX SUFFIX [{ target/xfail SELECTOR }]' 4493 Passes if REGEX does not match text in the dump file with 4494 suffix SUFFIX. 4495 4496 `scan-tree-dump-dem REGEX SUFFIX [{ target/xfail SELECTOR }]' 4497 Passes if REGEX matches demangled text in the dump file with 4498 suffix SUFFIX. 4499 4500 `scan-tree-dump-dem-not REGEX SUFFIX [{ target/xfail SELECTOR }]' 4501 Passes if REGEX does not match demangled text in the dump 4502 file with suffix SUFFIX. 4503 4504 `output-exists [{ target/xfail SELECTOR }]' 4505 Passes if compiler output file exists. 4506 4507 `output-exists-not [{ target/xfail SELECTOR }]' 4508 Passes if compiler output file does not exist. 4509 4510 `run-gcov SOURCEFILE' 4511 Check line counts in `gcov' tests. 4512 4513 `run-gcov [branches] [calls] { OPTS SOURCEFILE }' 4514 Check branch and/or call counts, in addition to line counts, 4515 in `gcov' tests. 4516 4517 4518 File: gccint.info, Node: Ada Tests, Next: C Tests, Prev: Test Directives, Up: Testsuites 4519 4520 6.4.3 Ada Language Testsuites 4521 ----------------------------- 4522 4523 The Ada testsuite includes executable tests from the ACATS 2.5 4524 testsuite, publicly available at 4525 `http://www.adaic.org/compilers/acats/2.5' 4526 4527 These tests are integrated in the GCC testsuite in the 4528 `gcc/testsuite/ada/acats' directory, and enabled automatically when 4529 running `make check', assuming the Ada language has been enabled when 4530 configuring GCC. 4531 4532 You can also run the Ada testsuite independently, using `make 4533 check-ada', or run a subset of the tests by specifying which chapter to 4534 run, e.g.: 4535 4536 $ make check-ada CHAPTERS="c3 c9" 4537 4538 The tests are organized by directory, each directory corresponding to 4539 a chapter of the Ada Reference Manual. So for example, c9 corresponds 4540 to chapter 9, which deals with tasking features of the language. 4541 4542 There is also an extra chapter called `gcc' containing a template for 4543 creating new executable tests. 4544 4545 The tests are run using two `sh' scripts: `run_acats' and 4546 `run_all.sh'. To run the tests using a simulator or a cross target, 4547 see the small customization section at the top of `run_all.sh'. 4548 4549 These tests are run using the build tree: they can be run without doing 4550 a `make install'. 4551 4552 4553 File: gccint.info, Node: C Tests, Next: libgcj Tests, Prev: Ada Tests, Up: Testsuites 4554 4555 6.4.4 C Language Testsuites 4556 --------------------------- 4557 4558 GCC contains the following C language testsuites, in the 4559 `gcc/testsuite' directory: 4560 4561 `gcc.dg' 4562 This contains tests of particular features of the C compiler, 4563 using the more modern `dg' harness. Correctness tests for various 4564 compiler features should go here if possible. 4565 4566 Magic comments determine whether the file is preprocessed, 4567 compiled, linked or run. In these tests, error and warning 4568 message texts are compared against expected texts or regular 4569 expressions given in comments. These tests are run with the 4570 options `-ansi -pedantic' unless other options are given in the 4571 test. Except as noted below they are not run with multiple 4572 optimization options. 4573 4574 `gcc.dg/compat' 4575 This subdirectory contains tests for binary compatibility using 4576 `compat.exp', which in turn uses the language-independent support 4577 (*note Support for testing binary compatibility: compat Testing.). 4578 4579 `gcc.dg/cpp' 4580 This subdirectory contains tests of the preprocessor. 4581 4582 `gcc.dg/debug' 4583 This subdirectory contains tests for debug formats. Tests in this 4584 subdirectory are run for each debug format that the compiler 4585 supports. 4586 4587 `gcc.dg/format' 4588 This subdirectory contains tests of the `-Wformat' format 4589 checking. Tests in this directory are run with and without 4590 `-DWIDE'. 4591 4592 `gcc.dg/noncompile' 4593 This subdirectory contains tests of code that should not compile 4594 and does not need any special compilation options. They are run 4595 with multiple optimization options, since sometimes invalid code 4596 crashes the compiler with optimization. 4597 4598 `gcc.dg/special' 4599 FIXME: describe this. 4600 4601 `gcc.c-torture' 4602 This contains particular code fragments which have historically 4603 broken easily. These tests are run with multiple optimization 4604 options, so tests for features which only break at some 4605 optimization levels belong here. This also contains tests to 4606 check that certain optimizations occur. It might be worthwhile to 4607 separate the correctness tests cleanly from the code quality 4608 tests, but it hasn't been done yet. 4609 4610 `gcc.c-torture/compat' 4611 FIXME: describe this. 4612 4613 This directory should probably not be used for new tests. 4614 4615 `gcc.c-torture/compile' 4616 This testsuite contains test cases that should compile, but do not 4617 need to link or run. These test cases are compiled with several 4618 different combinations of optimization options. All warnings are 4619 disabled for these test cases, so this directory is not suitable if 4620 you wish to test for the presence or absence of compiler warnings. 4621 While special options can be set, and tests disabled on specific 4622 platforms, by the use of `.x' files, mostly these test cases 4623 should not contain platform dependencies. FIXME: discuss how 4624 defines such as `NO_LABEL_VALUES' and `STACK_SIZE' are used. 4625 4626 `gcc.c-torture/execute' 4627 This testsuite contains test cases that should compile, link and 4628 run; otherwise the same comments as for `gcc.c-torture/compile' 4629 apply. 4630 4631 `gcc.c-torture/execute/ieee' 4632 This contains tests which are specific to IEEE floating point. 4633 4634 `gcc.c-torture/unsorted' 4635 FIXME: describe this. 4636 4637 This directory should probably not be used for new tests. 4638 4639 `gcc.c-torture/misc-tests' 4640 This directory contains C tests that require special handling. 4641 Some of these tests have individual expect files, and others share 4642 special-purpose expect files: 4643 4644 ``bprob*.c'' 4645 Test `-fbranch-probabilities' using `bprob.exp', which in 4646 turn uses the generic, language-independent framework (*note 4647 Support for testing profile-directed optimizations: profopt 4648 Testing.). 4649 4650 ``dg-*.c'' 4651 Test the testsuite itself using `dg-test.exp'. 4652 4653 ``gcov*.c'' 4654 Test `gcov' output using `gcov.exp', which in turn uses the 4655 language-independent support (*note Support for testing gcov: 4656 gcov Testing.). 4657 4658 ``i386-pf-*.c'' 4659 Test i386-specific support for data prefetch using 4660 `i386-prefetch.exp'. 4661 4662 4663 FIXME: merge in `testsuite/README.gcc' and discuss the format of test 4664 cases and magic comments more. 4665 4666 4667 File: gccint.info, Node: libgcj Tests, Next: gcov Testing, Prev: C Tests, Up: Testsuites 4668 4669 6.4.5 The Java library testsuites. 4670 ---------------------------------- 4671 4672 Runtime tests are executed via `make check' in the 4673 `TARGET/libjava/testsuite' directory in the build tree. Additional 4674 runtime tests can be checked into this testsuite. 4675 4676 Regression testing of the core packages in libgcj is also covered by 4677 the Mauve testsuite. The Mauve Project develops tests for the Java 4678 Class Libraries. These tests are run as part of libgcj testing by 4679 placing the Mauve tree within the libjava testsuite sources at 4680 `libjava/testsuite/libjava.mauve/mauve', or by specifying the location 4681 of that tree when invoking `make', as in `make MAUVEDIR=~/mauve check'. 4682 4683 To detect regressions, a mechanism in `mauve.exp' compares the 4684 failures for a test run against the list of expected failures in 4685 `libjava/testsuite/libjava.mauve/xfails' from the source hierarchy. 4686 Update this file when adding new failing tests to Mauve, or when fixing 4687 bugs in libgcj that had caused Mauve test failures. 4688 4689 We encourage developers to contribute test cases to Mauve. 4690 4691 4692 File: gccint.info, Node: gcov Testing, Next: profopt Testing, Prev: libgcj Tests, Up: Testsuites 4693 4694 6.4.6 Support for testing `gcov' 4695 -------------------------------- 4696 4697 Language-independent support for testing `gcov', and for checking that 4698 branch profiling produces expected values, is provided by the expect 4699 file `gcov.exp'. `gcov' tests also rely on procedures in `gcc.dg.exp' 4700 to compile and run the test program. A typical `gcov' test contains 4701 the following DejaGnu commands within comments: 4702 4703 { dg-options "-fprofile-arcs -ftest-coverage" } 4704 { dg-do run { target native } } 4705 { dg-final { run-gcov sourcefile } } 4706 4707 Checks of `gcov' output can include line counts, branch percentages, 4708 and call return percentages. All of these checks are requested via 4709 commands that appear in comments in the test's source file. Commands 4710 to check line counts are processed by default. Commands to check 4711 branch percentages and call return percentages are processed if the 4712 `run-gcov' command has arguments `branches' or `calls', respectively. 4713 For example, the following specifies checking both, as well as passing 4714 `-b' to `gcov': 4715 4716 { dg-final { run-gcov branches calls { -b sourcefile } } } 4717 4718 A line count command appears within a comment on the source line that 4719 is expected to get the specified count and has the form `count(CNT)'. 4720 A test should only check line counts for lines that will get the same 4721 count for any architecture. 4722 4723 Commands to check branch percentages (`branch') and call return 4724 percentages (`returns') are very similar to each other. A beginning 4725 command appears on or before the first of a range of lines that will 4726 report the percentage, and the ending command follows that range of 4727 lines. The beginning command can include a list of percentages, all of 4728 which are expected to be found within the range. A range is terminated 4729 by the next command of the same kind. A command `branch(end)' or 4730 `returns(end)' marks the end of a range without starting a new one. 4731 For example: 4732 4733 if (i > 10 && j > i && j < 20) /* branch(27 50 75) */ 4734 /* branch(end) */ 4735 foo (i, j); 4736 4737 For a call return percentage, the value specified is the percentage of 4738 calls reported to return. For a branch percentage, the value is either 4739 the expected percentage or 100 minus that value, since the direction of 4740 a branch can differ depending on the target or the optimization level. 4741 4742 Not all branches and calls need to be checked. A test should not 4743 check for branches that might be optimized away or replaced with 4744 predicated instructions. Don't check for calls inserted by the 4745 compiler or ones that might be inlined or optimized away. 4746 4747 A single test can check for combinations of line counts, branch 4748 percentages, and call return percentages. The command to check a line 4749 count must appear on the line that will report that count, but commands 4750 to check branch percentages and call return percentages can bracket the 4751 lines that report them. 4752 4753 4754 File: gccint.info, Node: profopt Testing, Next: compat Testing, Prev: gcov Testing, Up: Testsuites 4755 4756 6.4.7 Support for testing profile-directed optimizations 4757 -------------------------------------------------------- 4758 4759 The file `profopt.exp' provides language-independent support for 4760 checking correct execution of a test built with profile-directed 4761 optimization. This testing requires that a test program be built and 4762 executed twice. The first time it is compiled to generate profile 4763 data, and the second time it is compiled to use the data that was 4764 generated during the first execution. The second execution is to 4765 verify that the test produces the expected results. 4766 4767 To check that the optimization actually generated better code, a test 4768 can be built and run a third time with normal optimizations to verify 4769 that the performance is better with the profile-directed optimizations. 4770 `profopt.exp' has the beginnings of this kind of support. 4771 4772 `profopt.exp' provides generic support for profile-directed 4773 optimizations. Each set of tests that uses it provides information 4774 about a specific optimization: 4775 4776 `tool' 4777 tool being tested, e.g., `gcc' 4778 4779 `profile_option' 4780 options used to generate profile data 4781 4782 `feedback_option' 4783 options used to optimize using that profile data 4784 4785 `prof_ext' 4786 suffix of profile data files 4787 4788 `PROFOPT_OPTIONS' 4789 list of options with which to run each test, similar to the lists 4790 for torture tests 4791 4792 4793 File: gccint.info, Node: compat Testing, Next: Torture Tests, Prev: profopt Testing, Up: Testsuites 4794 4795 6.4.8 Support for testing binary compatibility 4796 ---------------------------------------------- 4797 4798 The file `compat.exp' provides language-independent support for binary 4799 compatibility testing. It supports testing interoperability of two 4800 compilers that follow the same ABI, or of multiple sets of compiler 4801 options that should not affect binary compatibility. It is intended to 4802 be used for testsuites that complement ABI testsuites. 4803 4804 A test supported by this framework has three parts, each in a separate 4805 source file: a main program and two pieces that interact with each 4806 other to split up the functionality being tested. 4807 4808 `TESTNAME_main.SUFFIX' 4809 Contains the main program, which calls a function in file 4810 `TESTNAME_x.SUFFIX'. 4811 4812 `TESTNAME_x.SUFFIX' 4813 Contains at least one call to a function in `TESTNAME_y.SUFFIX'. 4814 4815 `TESTNAME_y.SUFFIX' 4816 Shares data with, or gets arguments from, `TESTNAME_x.SUFFIX'. 4817 4818 Within each test, the main program and one functional piece are 4819 compiled by the GCC under test. The other piece can be compiled by an 4820 alternate compiler. If no alternate compiler is specified, then all 4821 three source files are all compiled by the GCC under test. You can 4822 specify pairs of sets of compiler options. The first element of such a 4823 pair specifies options used with the GCC under test, and the second 4824 element of the pair specifies options used with the alternate compiler. 4825 Each test is compiled with each pair of options. 4826 4827 `compat.exp' defines default pairs of compiler options. These can be 4828 overridden by defining the environment variable `COMPAT_OPTIONS' as: 4829 4830 COMPAT_OPTIONS="[list [list {TST1} {ALT1}] 4831 ...[list {TSTN} {ALTN}]]" 4832 4833 where TSTI and ALTI are lists of options, with TSTI used by the 4834 compiler under test and ALTI used by the alternate compiler. For 4835 example, with `[list [list {-g -O0} {-O3}] [list {-fpic} {-fPIC -O2}]]', 4836 the test is first built with `-g -O0' by the compiler under test and 4837 with `-O3' by the alternate compiler. The test is built a second time 4838 using `-fpic' by the compiler under test and `-fPIC -O2' by the 4839 alternate compiler. 4840 4841 An alternate compiler is specified by defining an environment variable 4842 to be the full pathname of an installed compiler; for C define 4843 `ALT_CC_UNDER_TEST', and for C++ define `ALT_CXX_UNDER_TEST'. These 4844 will be written to the `site.exp' file used by DejaGnu. The default is 4845 to build each test with the compiler under test using the first of each 4846 pair of compiler options from `COMPAT_OPTIONS'. When 4847 `ALT_CC_UNDER_TEST' or `ALT_CXX_UNDER_TEST' is `same', each test is 4848 built using the compiler under test but with combinations of the 4849 options from `COMPAT_OPTIONS'. 4850 4851 To run only the C++ compatibility suite using the compiler under test 4852 and another version of GCC using specific compiler options, do the 4853 following from `OBJDIR/gcc': 4854 4855 rm site.exp 4856 make -k \ 4857 ALT_CXX_UNDER_TEST=${alt_prefix}/bin/g++ \ 4858 COMPAT_OPTIONS="lists as shown above" \ 4859 check-c++ \ 4860 RUNTESTFLAGS="compat.exp" 4861 4862 A test that fails when the source files are compiled with different 4863 compilers, but passes when the files are compiled with the same 4864 compiler, demonstrates incompatibility of the generated code or runtime 4865 support. A test that fails for the alternate compiler but passes for 4866 the compiler under test probably tests for a bug that was fixed in the 4867 compiler under test but is present in the alternate compiler. 4868 4869 The binary compatibility tests support a small number of test framework 4870 commands that appear within comments in a test file. 4871 4872 `dg-require-*' 4873 These commands can be used in `TESTNAME_main.SUFFIX' to skip the 4874 test if specific support is not available on the target. 4875 4876 `dg-options' 4877 The specified options are used for compiling this particular source 4878 file, appended to the options from `COMPAT_OPTIONS'. When this 4879 command appears in `TESTNAME_main.SUFFIX' the options are also 4880 used to link the test program. 4881 4882 `dg-xfail-if' 4883 This command can be used in a secondary source file to specify that 4884 compilation is expected to fail for particular options on 4885 particular targets. 4886 4887 4888 File: gccint.info, Node: Torture Tests, Prev: compat Testing, Up: Testsuites 4889 4890 6.4.9 Support for torture testing using multiple options 4891 -------------------------------------------------------- 4892 4893 Throughout the compiler testsuite there are several directories whose 4894 tests are run multiple times, each with a different set of options. 4895 These are known as torture tests. 4896 `gcc/testsuite/lib/torture-options.exp' defines procedures to set up 4897 these lists: 4898 4899 `torture-init' 4900 Initialize use of torture lists. 4901 4902 `set-torture-options' 4903 Set lists of torture options to use for tests with and without 4904 loops. Optionally combine a set of torture options with a set of 4905 other options, as is done with Objective-C runtime options. 4906 4907 `torture-finish' 4908 Finalize use of torture lists. 4909 4910 The `.exp' file for a set of tests that use torture options must 4911 include calls to these three procedures if: 4912 4913 * It calls `gcc-dg-runtest' and overrides DG_TORTURE_OPTIONS. 4914 4915 * It calls ${TOOL}`-torture' or ${TOOL}`-torture-execute', where 4916 TOOL is `c', `fortran', or `objc'. 4917 4918 * It calls `dg-pch'. 4919 4920 It is not necessary for a `.exp' file that calls `gcc-dg-runtest' to 4921 call the torture procedures if the tests should use the list in 4922 DG_TORTURE_OPTIONS defined in `gcc-dg.exp'. 4923 4924 Most uses of torture options can override the default lists by defining 4925 TORTURE_OPTIONS or add to the default list by defining 4926 ADDITIONAL_TORTURE_OPTIONS. Define these in a `.dejagnurc' file or add 4927 them to the `site.exp' file; for example 4928 4929 set ADDITIONAL_TORTURE_OPTIONS [list \ 4930 { -O2 -ftree-loop-linear } \ 4931 { -O2 -fpeel-loops } ] 4932 4933 4934 File: gccint.info, Node: Options, Next: Passes, Prev: Source Tree, Up: Top 4935 4936 7 Option specification files 4937 **************************** 4938 4939 Most GCC command-line options are described by special option 4940 definition files, the names of which conventionally end in `.opt'. 4941 This chapter describes the format of these files. 4942 4943 * Menu: 4944 4945 * Option file format:: The general layout of the files 4946 * Option properties:: Supported option properties 4947 4948 4949 File: gccint.info, Node: Option file format, Next: Option properties, Up: Options 4950 4951 7.1 Option file format 4952 ====================== 4953 4954 Option files are a simple list of records in which each field occupies 4955 its own line and in which the records themselves are separated by blank 4956 lines. Comments may appear on their own line anywhere within the file 4957 and are preceded by semicolons. Whitespace is allowed before the 4958 semicolon. 4959 4960 The files can contain the following types of record: 4961 4962 * A language definition record. These records have two fields: the 4963 string `Language' and the name of the language. Once a language 4964 has been declared in this way, it can be used as an option 4965 property. *Note Option properties::. 4966 4967 * A target specific save record to save additional information. These 4968 records have two fields: the string `TargetSave', and a 4969 declaration type to go in the `cl_target_option' structure. 4970 4971 * An option definition record. These records have the following 4972 fields: 4973 1. the name of the option, with the leading "-" removed 4974 4975 2. a space-separated list of option properties (*note Option 4976 properties::) 4977 4978 3. the help text to use for `--help' (omitted if the second field 4979 contains the `Undocumented' property). 4980 4981 By default, all options beginning with "f", "W" or "m" are 4982 implicitly assumed to take a "no-" form. This form should not be 4983 listed separately. If an option beginning with one of these 4984 letters does not have a "no-" form, you can use the 4985 `RejectNegative' property to reject it. 4986 4987 The help text is automatically line-wrapped before being displayed. 4988 Normally the name of the option is printed on the left-hand side of 4989 the output and the help text is printed on the right. However, if 4990 the help text contains a tab character, the text to the left of 4991 the tab is used instead of the option's name and the text to the 4992 right of the tab forms the help text. This allows you to 4993 elaborate on what type of argument the option takes. 4994 4995 * A target mask record. These records have one field of the form 4996 `Mask(X)'. The options-processing script will automatically 4997 allocate a bit in `target_flags' (*note Run-time Target::) for 4998 each mask name X and set the macro `MASK_X' to the appropriate 4999 bitmask. It will also declare a `TARGET_X' macro that has the 5000 value 1 when bit `MASK_X' is set and 0 otherwise. 5001 5002 They are primarily intended to declare target masks that are not 5003 associated with user options, either because these masks represent 5004 internal switches or because the options are not available on all 5005 configurations and yet the masks always need to be defined. 5006 5007 5008 File: gccint.info, Node: Option properties, Prev: Option file format, Up: Options 5009 5010 7.2 Option properties 5011 ===================== 5012 5013 The second field of an option record can specify the following 5014 properties: 5015 5016 `Common' 5017 The option is available for all languages and targets. 5018 5019 `Target' 5020 The option is available for all languages but is target-specific. 5021 5022 `LANGUAGE' 5023 The option is available when compiling for the given language. 5024 5025 It is possible to specify several different languages for the same 5026 option. Each LANGUAGE must have been declared by an earlier 5027 `Language' record. *Note Option file format::. 5028 5029 `RejectNegative' 5030 The option does not have a "no-" form. All options beginning with 5031 "f", "W" or "m" are assumed to have a "no-" form unless this 5032 property is used. 5033 5034 `Negative(OTHERNAME)' 5035 The option will turn off another option OTHERNAME, which is the 5036 the option name with the leading "-" removed. This chain action 5037 will propagate through the `Negative' property of the option to be 5038 turned off. 5039 5040 `Joined' 5041 `Separate' 5042 The option takes a mandatory argument. `Joined' indicates that 5043 the option and argument can be included in the same `argv' entry 5044 (as with `-mflush-func=NAME', for example). `Separate' indicates 5045 that the option and argument can be separate `argv' entries (as 5046 with `-o'). An option is allowed to have both of these properties. 5047 5048 `JoinedOrMissing' 5049 The option takes an optional argument. If the argument is given, 5050 it will be part of the same `argv' entry as the option itself. 5051 5052 This property cannot be used alongside `Joined' or `Separate'. 5053 5054 `UInteger' 5055 The option's argument is a non-negative integer. The option parser 5056 will check and convert the argument before passing it to the 5057 relevant option handler. `UInteger' should also be used on 5058 options like `-falign-loops' where both `-falign-loops' and 5059 `-falign-loops'=N are supported to make sure the saved options are 5060 given a full integer. 5061 5062 `Var(VAR)' 5063 The state of this option should be stored in variable VAR. The 5064 way that the state is stored depends on the type of option: 5065 5066 * If the option uses the `Mask' or `InverseMask' properties, 5067 VAR is the integer variable that contains the mask. 5068 5069 * If the option is a normal on/off switch, VAR is an integer 5070 variable that is nonzero when the option is enabled. The 5071 options parser will set the variable to 1 when the positive 5072 form of the option is used and 0 when the "no-" form is used. 5073 5074 * If the option takes an argument and has the `UInteger' 5075 property, VAR is an integer variable that stores the value of 5076 the argument. 5077 5078 * Otherwise, if the option takes an argument, VAR is a pointer 5079 to the argument string. The pointer will be null if the 5080 argument is optional and wasn't given. 5081 5082 The option-processing script will usually declare VAR in 5083 `options.c' and leave it to be zero-initialized at start-up time. 5084 You can modify this behavior using `VarExists' and `Init'. 5085 5086 `Var(VAR, SET)' 5087 The option controls an integer variable VAR and is active when VAR 5088 equals SET. The option parser will set VAR to SET when the 5089 positive form of the option is used and `!SET' when the "no-" form 5090 is used. 5091 5092 VAR is declared in the same way as for the single-argument form 5093 described above. 5094 5095 `VarExists' 5096 The variable specified by the `Var' property already exists. No 5097 definition should be added to `options.c' in response to this 5098 option record. 5099 5100 You should use this property only if the variable is declared 5101 outside `options.c'. 5102 5103 `Init(VALUE)' 5104 The variable specified by the `Var' property should be statically 5105 initialized to VALUE. 5106 5107 `Mask(NAME)' 5108 The option is associated with a bit in the `target_flags' variable 5109 (*note Run-time Target::) and is active when that bit is set. You 5110 may also specify `Var' to select a variable other than 5111 `target_flags'. 5112 5113 The options-processing script will automatically allocate a unique 5114 bit for the option. If the option is attached to `target_flags', 5115 the script will set the macro `MASK_NAME' to the appropriate 5116 bitmask. It will also declare a `TARGET_NAME' macro that has the 5117 value 1 when the option is active and 0 otherwise. If you use 5118 `Var' to attach the option to a different variable, the associated 5119 macros are called `OPTION_MASK_NAME' and `OPTION_NAME' 5120 respectively. 5121 5122 You can disable automatic bit allocation using `MaskExists'. 5123 5124 `InverseMask(OTHERNAME)' 5125 `InverseMask(OTHERNAME, THISNAME)' 5126 The option is the inverse of another option that has the 5127 `Mask(OTHERNAME)' property. If THISNAME is given, the 5128 options-processing script will declare a `TARGET_THISNAME' macro 5129 that is 1 when the option is active and 0 otherwise. 5130 5131 `MaskExists' 5132 The mask specified by the `Mask' property already exists. No 5133 `MASK' or `TARGET' definitions should be added to `options.h' in 5134 response to this option record. 5135 5136 The main purpose of this property is to support synonymous options. 5137 The first option should use `Mask(NAME)' and the others should use 5138 `Mask(NAME) MaskExists'. 5139 5140 `Report' 5141 The state of the option should be printed by `-fverbose-asm'. 5142 5143 `Undocumented' 5144 The option is deliberately missing documentation and should not be 5145 included in the `--help' output. 5146 5147 `Condition(COND)' 5148 The option should only be accepted if preprocessor condition COND 5149 is true. Note that any C declarations associated with the option 5150 will be present even if COND is false; COND simply controls 5151 whether the option is accepted and whether it is printed in the 5152 `--help' output. 5153 5154 `Save' 5155 Build the `cl_target_option' structure to hold a copy of the 5156 option, add the functions `cl_target_option_save' and 5157 `cl_target_option_restore' to save and restore the options. 5158 5159 5160 File: gccint.info, Node: Passes, Next: Trees, Prev: Options, Up: Top 5161 5162 8 Passes and Files of the Compiler 5163 ********************************** 5164 5165 This chapter is dedicated to giving an overview of the optimization and 5166 code generation passes of the compiler. In the process, it describes 5167 some of the language front end interface, though this description is no 5168 where near complete. 5169 5170 * Menu: 5171 5172 * Parsing pass:: The language front end turns text into bits. 5173 * Gimplification pass:: The bits are turned into something we can optimize. 5174 * Pass manager:: Sequencing the optimization passes. 5175 * Tree-SSA passes:: Optimizations on a high-level representation. 5176 * RTL passes:: Optimizations on a low-level representation. 5177 5178 5179 File: gccint.info, Node: Parsing pass, Next: Gimplification pass, Up: Passes 5180 5181 8.1 Parsing pass 5182 ================ 5183 5184 The language front end is invoked only once, via 5185 `lang_hooks.parse_file', to parse the entire input. The language front 5186 end may use any intermediate language representation deemed 5187 appropriate. The C front end uses GENERIC trees (CROSSREF), plus a 5188 double handful of language specific tree codes defined in 5189 `c-common.def'. The Fortran front end uses a completely different 5190 private representation. 5191 5192 At some point the front end must translate the representation used in 5193 the front end to a representation understood by the language-independent 5194 portions of the compiler. Current practice takes one of two forms. 5195 The C front end manually invokes the gimplifier (CROSSREF) on each 5196 function, and uses the gimplifier callbacks to convert the 5197 language-specific tree nodes directly to GIMPLE (CROSSREF) before 5198 passing the function off to be compiled. The Fortran front end 5199 converts from a private representation to GENERIC, which is later 5200 lowered to GIMPLE when the function is compiled. Which route to choose 5201 probably depends on how well GENERIC (plus extensions) can be made to 5202 match up with the source language and necessary parsing data structures. 5203 5204 BUG: Gimplification must occur before nested function lowering, and 5205 nested function lowering must be done by the front end before passing 5206 the data off to cgraph. 5207 5208 TODO: Cgraph should control nested function lowering. It would only 5209 be invoked when it is certain that the outer-most function is used. 5210 5211 TODO: Cgraph needs a gimplify_function callback. It should be invoked 5212 when (1) it is certain that the function is used, (2) warning flags 5213 specified by the user require some amount of compilation in order to 5214 honor, (3) the language indicates that semantic analysis is not 5215 complete until gimplification occurs. Hum... this sounds overly 5216 complicated. Perhaps we should just have the front end gimplify 5217 always; in most cases it's only one function call. 5218 5219 The front end needs to pass all function definitions and top level 5220 declarations off to the middle-end so that they can be compiled and 5221 emitted to the object file. For a simple procedural language, it is 5222 usually most convenient to do this as each top level declaration or 5223 definition is seen. There is also a distinction to be made between 5224 generating functional code and generating complete debug information. 5225 The only thing that is absolutely required for functional code is that 5226 function and data _definitions_ be passed to the middle-end. For 5227 complete debug information, function, data and type declarations should 5228 all be passed as well. 5229 5230 In any case, the front end needs each complete top-level function or 5231 data declaration, and each data definition should be passed to 5232 `rest_of_decl_compilation'. Each complete type definition should be 5233 passed to `rest_of_type_compilation'. Each function definition should 5234 be passed to `cgraph_finalize_function'. 5235 5236 TODO: I know rest_of_compilation currently has all sorts of 5237 rtl-generation semantics. I plan to move all code generation bits 5238 (both tree and rtl) to compile_function. Should we hide cgraph from 5239 the front ends and move back to rest_of_compilation as the official 5240 interface? Possibly we should rename all three interfaces such that 5241 the names match in some meaningful way and that is more descriptive 5242 than "rest_of". 5243 5244 The middle-end will, at its option, emit the function and data 5245 definitions immediately or queue them for later processing. 5246 5247 5248 File: gccint.info, Node: Gimplification pass, Next: Pass manager, Prev: Parsing pass, Up: Passes 5249 5250 8.2 Gimplification pass 5251 ======================= 5252 5253 "Gimplification" is a whimsical term for the process of converting the 5254 intermediate representation of a function into the GIMPLE language 5255 (CROSSREF). The term stuck, and so words like "gimplification", 5256 "gimplify", "gimplifier" and the like are sprinkled throughout this 5257 section of code. 5258 5259 While a front end may certainly choose to generate GIMPLE directly if 5260 it chooses, this can be a moderately complex process unless the 5261 intermediate language used by the front end is already fairly simple. 5262 Usually it is easier to generate GENERIC trees plus extensions and let 5263 the language-independent gimplifier do most of the work. 5264 5265 The main entry point to this pass is `gimplify_function_tree' located 5266 in `gimplify.c'. From here we process the entire function gimplifying 5267 each statement in turn. The main workhorse for this pass is 5268 `gimplify_expr'. Approximately everything passes through here at least 5269 once, and it is from here that we invoke the `lang_hooks.gimplify_expr' 5270 callback. 5271 5272 The callback should examine the expression in question and return 5273 `GS_UNHANDLED' if the expression is not a language specific construct 5274 that requires attention. Otherwise it should alter the expression in 5275 some way to such that forward progress is made toward producing valid 5276 GIMPLE. If the callback is certain that the transformation is complete 5277 and the expression is valid GIMPLE, it should return `GS_ALL_DONE'. 5278 Otherwise it should return `GS_OK', which will cause the expression to 5279 be processed again. If the callback encounters an error during the 5280 transformation (because the front end is relying on the gimplification 5281 process to finish semantic checks), it should return `GS_ERROR'. 5282 5283 5284 File: gccint.info, Node: Pass manager, Next: Tree-SSA passes, Prev: Gimplification pass, Up: Passes 5285 5286 8.3 Pass manager 5287 ================ 5288 5289 The pass manager is located in `passes.c', `tree-optimize.c' and 5290 `tree-pass.h'. Its job is to run all of the individual passes in the 5291 correct order, and take care of standard bookkeeping that applies to 5292 every pass. 5293 5294 The theory of operation is that each pass defines a structure that 5295 represents everything we need to know about that pass--when it should 5296 be run, how it should be run, what intermediate language form or 5297 on-the-side data structures it needs. We register the pass to be run 5298 in some particular order, and the pass manager arranges for everything 5299 to happen in the correct order. 5300 5301 The actuality doesn't completely live up to the theory at present. 5302 Command-line switches and `timevar_id_t' enumerations must still be 5303 defined elsewhere. The pass manager validates constraints but does not 5304 attempt to (re-)generate data structures or lower intermediate language 5305 form based on the requirements of the next pass. Nevertheless, what is 5306 present is useful, and a far sight better than nothing at all. 5307 5308 Each pass may have its own dump file (for GCC debugging purposes). 5309 Passes without any names, or with a name starting with a star, do not 5310 dump anything. 5311 5312 TODO: describe the global variables set up by the pass manager, and a 5313 brief description of how a new pass should use it. I need to look at 5314 what info rtl passes use first.... 5315 5316 5317 File: gccint.info, Node: Tree-SSA passes, Next: RTL passes, Prev: Pass manager, Up: Passes 5318 5319 8.4 Tree-SSA passes 5320 =================== 5321 5322 The following briefly describes the tree optimization passes that are 5323 run after gimplification and what source files they are located in. 5324 5325 * Remove useless statements 5326 5327 This pass is an extremely simple sweep across the gimple code in 5328 which we identify obviously dead code and remove it. Here we do 5329 things like simplify `if' statements with constant conditions, 5330 remove exception handling constructs surrounding code that 5331 obviously cannot throw, remove lexical bindings that contain no 5332 variables, and other assorted simplistic cleanups. The idea is to 5333 get rid of the obvious stuff quickly rather than wait until later 5334 when it's more work to get rid of it. This pass is located in 5335 `tree-cfg.c' and described by `pass_remove_useless_stmts'. 5336 5337 * Mudflap declaration registration 5338 5339 If mudflap (*note -fmudflap -fmudflapth -fmudflapir: (gcc)Optimize 5340 Options.) is enabled, we generate code to register some variable 5341 declarations with the mudflap runtime. Specifically, the runtime 5342 tracks the lifetimes of those variable declarations that have 5343 their addresses taken, or whose bounds are unknown at compile time 5344 (`extern'). This pass generates new exception handling constructs 5345 (`try'/`finally'), and so must run before those are lowered. In 5346 addition, the pass enqueues declarations of static variables whose 5347 lifetimes extend to the entire program. The pass is located in 5348 `tree-mudflap.c' and is described by `pass_mudflap_1'. 5349 5350 * OpenMP lowering 5351 5352 If OpenMP generation (`-fopenmp') is enabled, this pass lowers 5353 OpenMP constructs into GIMPLE. 5354 5355 Lowering of OpenMP constructs involves creating replacement 5356 expressions for local variables that have been mapped using data 5357 sharing clauses, exposing the control flow of most synchronization 5358 directives and adding region markers to facilitate the creation of 5359 the control flow graph. The pass is located in `omp-low.c' and is 5360 described by `pass_lower_omp'. 5361 5362 * OpenMP expansion 5363 5364 If OpenMP generation (`-fopenmp') is enabled, this pass expands 5365 parallel regions into their own functions to be invoked by the 5366 thread library. The pass is located in `omp-low.c' and is 5367 described by `pass_expand_omp'. 5368 5369 * Lower control flow 5370 5371 This pass flattens `if' statements (`COND_EXPR') and moves lexical 5372 bindings (`BIND_EXPR') out of line. After this pass, all `if' 5373 statements will have exactly two `goto' statements in its `then' 5374 and `else' arms. Lexical binding information for each statement 5375 will be found in `TREE_BLOCK' rather than being inferred from its 5376 position under a `BIND_EXPR'. This pass is found in 5377 `gimple-low.c' and is described by `pass_lower_cf'. 5378 5379 * Lower exception handling control flow 5380 5381 This pass decomposes high-level exception handling constructs 5382 (`TRY_FINALLY_EXPR' and `TRY_CATCH_EXPR') into a form that 5383 explicitly represents the control flow involved. After this pass, 5384 `lookup_stmt_eh_region' will return a non-negative number for any 5385 statement that may have EH control flow semantics; examine 5386 `tree_can_throw_internal' or `tree_can_throw_external' for exact 5387 semantics. Exact control flow may be extracted from 5388 `foreach_reachable_handler'. The EH region nesting tree is defined 5389 in `except.h' and built in `except.c'. The lowering pass itself 5390 is in `tree-eh.c' and is described by `pass_lower_eh'. 5391 5392 * Build the control flow graph 5393 5394 This pass decomposes a function into basic blocks and creates all 5395 of the edges that connect them. It is located in `tree-cfg.c' and 5396 is described by `pass_build_cfg'. 5397 5398 * Find all referenced variables 5399 5400 This pass walks the entire function and collects an array of all 5401 variables referenced in the function, `referenced_vars'. The 5402 index at which a variable is found in the array is used as a UID 5403 for the variable within this function. This data is needed by the 5404 SSA rewriting routines. The pass is located in `tree-dfa.c' and 5405 is described by `pass_referenced_vars'. 5406 5407 * Enter static single assignment form 5408 5409 This pass rewrites the function such that it is in SSA form. After 5410 this pass, all `is_gimple_reg' variables will be referenced by 5411 `SSA_NAME', and all occurrences of other variables will be 5412 annotated with `VDEFS' and `VUSES'; PHI nodes will have been 5413 inserted as necessary for each basic block. This pass is located 5414 in `tree-ssa.c' and is described by `pass_build_ssa'. 5415 5416 * Warn for uninitialized variables 5417 5418 This pass scans the function for uses of `SSA_NAME's that are fed 5419 by default definition. For non-parameter variables, such uses are 5420 uninitialized. The pass is run twice, before and after 5421 optimization (if turned on). In the first pass we only warn for 5422 uses that are positively uninitialized; in the second pass we warn 5423 for uses that are possibly uninitialized. The pass is located in 5424 `tree-ssa.c' and is defined by `pass_early_warn_uninitialized' and 5425 `pass_late_warn_uninitialized'. 5426 5427 * Dead code elimination 5428 5429 This pass scans the function for statements without side effects 5430 whose result is unused. It does not do memory life analysis, so 5431 any value that is stored in memory is considered used. The pass 5432 is run multiple times throughout the optimization process. It is 5433 located in `tree-ssa-dce.c' and is described by `pass_dce'. 5434 5435 * Dominator optimizations 5436 5437 This pass performs trivial dominator-based copy and constant 5438 propagation, expression simplification, and jump threading. It is 5439 run multiple times throughout the optimization process. It it 5440 located in `tree-ssa-dom.c' and is described by `pass_dominator'. 5441 5442 * Forward propagation of single-use variables 5443 5444 This pass attempts to remove redundant computation by substituting 5445 variables that are used once into the expression that uses them and 5446 seeing if the result can be simplified. It is located in 5447 `tree-ssa-forwprop.c' and is described by `pass_forwprop'. 5448 5449 * Copy Renaming 5450 5451 This pass attempts to change the name of compiler temporaries 5452 involved in copy operations such that SSA->normal can coalesce the 5453 copy away. When compiler temporaries are copies of user 5454 variables, it also renames the compiler temporary to the user 5455 variable resulting in better use of user symbols. It is located 5456 in `tree-ssa-copyrename.c' and is described by `pass_copyrename'. 5457 5458 * PHI node optimizations 5459 5460 This pass recognizes forms of PHI inputs that can be represented as 5461 conditional expressions and rewrites them into straight line code. 5462 It is located in `tree-ssa-phiopt.c' and is described by 5463 `pass_phiopt'. 5464 5465 * May-alias optimization 5466 5467 This pass performs a flow sensitive SSA-based points-to analysis. 5468 The resulting may-alias, must-alias, and escape analysis 5469 information is used to promote variables from in-memory 5470 addressable objects to non-aliased variables that can be renamed 5471 into SSA form. We also update the `VDEF'/`VUSE' memory tags for 5472 non-renameable aggregates so that we get fewer false kills. The 5473 pass is located in `tree-ssa-alias.c' and is described by 5474 `pass_may_alias'. 5475 5476 Interprocedural points-to information is located in 5477 `tree-ssa-structalias.c' and described by `pass_ipa_pta'. 5478 5479 * Profiling 5480 5481 This pass rewrites the function in order to collect runtime block 5482 and value profiling data. Such data may be fed back into the 5483 compiler on a subsequent run so as to allow optimization based on 5484 expected execution frequencies. The pass is located in 5485 `predict.c' and is described by `pass_profile'. 5486 5487 * Lower complex arithmetic 5488 5489 This pass rewrites complex arithmetic operations into their 5490 component scalar arithmetic operations. The pass is located in 5491 `tree-complex.c' and is described by `pass_lower_complex'. 5492 5493 * Scalar replacement of aggregates 5494 5495 This pass rewrites suitable non-aliased local aggregate variables 5496 into a set of scalar variables. The resulting scalar variables are 5497 rewritten into SSA form, which allows subsequent optimization 5498 passes to do a significantly better job with them. The pass is 5499 located in `tree-sra.c' and is described by `pass_sra'. 5500 5501 * Dead store elimination 5502 5503 This pass eliminates stores to memory that are subsequently 5504 overwritten by another store, without any intervening loads. The 5505 pass is located in `tree-ssa-dse.c' and is described by `pass_dse'. 5506 5507 * Tail recursion elimination 5508 5509 This pass transforms tail recursion into a loop. It is located in 5510 `tree-tailcall.c' and is described by `pass_tail_recursion'. 5511 5512 * Forward store motion 5513 5514 This pass sinks stores and assignments down the flowgraph closer 5515 to their use point. The pass is located in `tree-ssa-sink.c' and 5516 is described by `pass_sink_code'. 5517 5518 * Partial redundancy elimination 5519 5520 This pass eliminates partially redundant computations, as well as 5521 performing load motion. The pass is located in `tree-ssa-pre.c' 5522 and is described by `pass_pre'. 5523 5524 Just before partial redundancy elimination, if 5525 `-funsafe-math-optimizations' is on, GCC tries to convert 5526 divisions to multiplications by the reciprocal. The pass is 5527 located in `tree-ssa-math-opts.c' and is described by 5528 `pass_cse_reciprocal'. 5529 5530 * Full redundancy elimination 5531 5532 This is a simpler form of PRE that only eliminates redundancies 5533 that occur an all paths. It is located in `tree-ssa-pre.c' and 5534 described by `pass_fre'. 5535 5536 * Loop optimization 5537 5538 The main driver of the pass is placed in `tree-ssa-loop.c' and 5539 described by `pass_loop'. 5540 5541 The optimizations performed by this pass are: 5542 5543 Loop invariant motion. This pass moves only invariants that would 5544 be hard to handle on rtl level (function calls, operations that 5545 expand to nontrivial sequences of insns). With `-funswitch-loops' 5546 it also moves operands of conditions that are invariant out of the 5547 loop, so that we can use just trivial invariantness analysis in 5548 loop unswitching. The pass also includes store motion. The pass 5549 is implemented in `tree-ssa-loop-im.c'. 5550 5551 Canonical induction variable creation. This pass creates a simple 5552 counter for number of iterations of the loop and replaces the exit 5553 condition of the loop using it, in case when a complicated 5554 analysis is necessary to determine the number of iterations. 5555 Later optimizations then may determine the number easily. The 5556 pass is implemented in `tree-ssa-loop-ivcanon.c'. 5557 5558 Induction variable optimizations. This pass performs standard 5559 induction variable optimizations, including strength reduction, 5560 induction variable merging and induction variable elimination. 5561 The pass is implemented in `tree-ssa-loop-ivopts.c'. 5562 5563 Loop unswitching. This pass moves the conditional jumps that are 5564 invariant out of the loops. To achieve this, a duplicate of the 5565 loop is created for each possible outcome of conditional jump(s). 5566 The pass is implemented in `tree-ssa-loop-unswitch.c'. This pass 5567 should eventually replace the rtl-level loop unswitching in 5568 `loop-unswitch.c', but currently the rtl-level pass is not 5569 completely redundant yet due to deficiencies in tree level alias 5570 analysis. 5571 5572 The optimizations also use various utility functions contained in 5573 `tree-ssa-loop-manip.c', `cfgloop.c', `cfgloopanal.c' and 5574 `cfgloopmanip.c'. 5575 5576 Vectorization. This pass transforms loops to operate on vector 5577 types instead of scalar types. Data parallelism across loop 5578 iterations is exploited to group data elements from consecutive 5579 iterations into a vector and operate on them in parallel. 5580 Depending on available target support the loop is conceptually 5581 unrolled by a factor `VF' (vectorization factor), which is the 5582 number of elements operated upon in parallel in each iteration, 5583 and the `VF' copies of each scalar operation are fused to form a 5584 vector operation. Additional loop transformations such as peeling 5585 and versioning may take place to align the number of iterations, 5586 and to align the memory accesses in the loop. The pass is 5587 implemented in `tree-vectorizer.c' (the main driver and general 5588 utilities), `tree-vect-analyze.c' and `tree-vect-transform.c'. 5589 Analysis of data references is in `tree-data-ref.c'. 5590 5591 Autoparallelization. This pass splits the loop iteration space to 5592 run into several threads. The pass is implemented in 5593 `tree-parloops.c'. 5594 5595 * Tree level if-conversion for vectorizer 5596 5597 This pass applies if-conversion to simple loops to help vectorizer. 5598 We identify if convertible loops, if-convert statements and merge 5599 basic blocks in one big block. The idea is to present loop in such 5600 form so that vectorizer can have one to one mapping between 5601 statements and available vector operations. This patch 5602 re-introduces COND_EXPR at GIMPLE level. This pass is located in 5603 `tree-if-conv.c' and is described by `pass_if_conversion'. 5604 5605 * Conditional constant propagation 5606 5607 This pass relaxes a lattice of values in order to identify those 5608 that must be constant even in the presence of conditional branches. 5609 The pass is located in `tree-ssa-ccp.c' and is described by 5610 `pass_ccp'. 5611 5612 A related pass that works on memory loads and stores, and not just 5613 register values, is located in `tree-ssa-ccp.c' and described by 5614 `pass_store_ccp'. 5615 5616 * Conditional copy propagation 5617 5618 This is similar to constant propagation but the lattice of values 5619 is the "copy-of" relation. It eliminates redundant copies from the 5620 code. The pass is located in `tree-ssa-copy.c' and described by 5621 `pass_copy_prop'. 5622 5623 A related pass that works on memory copies, and not just register 5624 copies, is located in `tree-ssa-copy.c' and described by 5625 `pass_store_copy_prop'. 5626 5627 * Value range propagation 5628 5629 This transformation is similar to constant propagation but instead 5630 of propagating single constant values, it propagates known value 5631 ranges. The implementation is based on Patterson's range 5632 propagation algorithm (Accurate Static Branch Prediction by Value 5633 Range Propagation, J. R. C. Patterson, PLDI '95). In contrast to 5634 Patterson's algorithm, this implementation does not propagate 5635 branch probabilities nor it uses more than a single range per SSA 5636 name. This means that the current implementation cannot be used 5637 for branch prediction (though adapting it would not be difficult). 5638 The pass is located in `tree-vrp.c' and is described by 5639 `pass_vrp'. 5640 5641 * Folding built-in functions 5642 5643 This pass simplifies built-in functions, as applicable, with 5644 constant arguments or with inferable string lengths. It is 5645 located in `tree-ssa-ccp.c' and is described by 5646 `pass_fold_builtins'. 5647 5648 * Split critical edges 5649 5650 This pass identifies critical edges and inserts empty basic blocks 5651 such that the edge is no longer critical. The pass is located in 5652 `tree-cfg.c' and is described by `pass_split_crit_edges'. 5653 5654 * Control dependence dead code elimination 5655 5656 This pass is a stronger form of dead code elimination that can 5657 eliminate unnecessary control flow statements. It is located in 5658 `tree-ssa-dce.c' and is described by `pass_cd_dce'. 5659 5660 * Tail call elimination 5661 5662 This pass identifies function calls that may be rewritten into 5663 jumps. No code transformation is actually applied here, but the 5664 data and control flow problem is solved. The code transformation 5665 requires target support, and so is delayed until RTL. In the 5666 meantime `CALL_EXPR_TAILCALL' is set indicating the possibility. 5667 The pass is located in `tree-tailcall.c' and is described by 5668 `pass_tail_calls'. The RTL transformation is handled by 5669 `fixup_tail_calls' in `calls.c'. 5670 5671 * Warn for function return without value 5672 5673 For non-void functions, this pass locates return statements that do 5674 not specify a value and issues a warning. Such a statement may 5675 have been injected by falling off the end of the function. This 5676 pass is run last so that we have as much time as possible to prove 5677 that the statement is not reachable. It is located in 5678 `tree-cfg.c' and is described by `pass_warn_function_return'. 5679 5680 * Mudflap statement annotation 5681 5682 If mudflap is enabled, we rewrite some memory accesses with code to 5683 validate that the memory access is correct. In particular, 5684 expressions involving pointer dereferences (`INDIRECT_REF', 5685 `ARRAY_REF', etc.) are replaced by code that checks the selected 5686 address range against the mudflap runtime's database of valid 5687 regions. This check includes an inline lookup into a 5688 direct-mapped cache, based on shift/mask operations of the pointer 5689 value, with a fallback function call into the runtime. The pass 5690 is located in `tree-mudflap.c' and is described by 5691 `pass_mudflap_2'. 5692 5693 * Leave static single assignment form 5694 5695 This pass rewrites the function such that it is in normal form. At 5696 the same time, we eliminate as many single-use temporaries as 5697 possible, so the intermediate language is no longer GIMPLE, but 5698 GENERIC. The pass is located in `tree-outof-ssa.c' and is 5699 described by `pass_del_ssa'. 5700 5701 * Merge PHI nodes that feed into one another 5702 5703 This is part of the CFG cleanup passes. It attempts to join PHI 5704 nodes from a forwarder CFG block into another block with PHI 5705 nodes. The pass is located in `tree-cfgcleanup.c' and is 5706 described by `pass_merge_phi'. 5707 5708 * Return value optimization 5709 5710 If a function always returns the same local variable, and that 5711 local variable is an aggregate type, then the variable is replaced 5712 with the return value for the function (i.e., the function's 5713 DECL_RESULT). This is equivalent to the C++ named return value 5714 optimization applied to GIMPLE. The pass is located in 5715 `tree-nrv.c' and is described by `pass_nrv'. 5716 5717 * Return slot optimization 5718 5719 If a function returns a memory object and is called as `var = 5720 foo()', this pass tries to change the call so that the address of 5721 `var' is sent to the caller to avoid an extra memory copy. This 5722 pass is located in `tree-nrv.c' and is described by 5723 `pass_return_slot'. 5724 5725 * Optimize calls to `__builtin_object_size' 5726 5727 This is a propagation pass similar to CCP that tries to remove 5728 calls to `__builtin_object_size' when the size of the object can be 5729 computed at compile-time. This pass is located in 5730 `tree-object-size.c' and is described by `pass_object_sizes'. 5731 5732 * Loop invariant motion 5733 5734 This pass removes expensive loop-invariant computations out of 5735 loops. The pass is located in `tree-ssa-loop.c' and described by 5736 `pass_lim'. 5737 5738 * Loop nest optimizations 5739 5740 This is a family of loop transformations that works on loop nests. 5741 It includes loop interchange, scaling, skewing and reversal and 5742 they are all geared to the optimization of data locality in array 5743 traversals and the removal of dependencies that hamper 5744 optimizations such as loop parallelization and vectorization. The 5745 pass is located in `tree-loop-linear.c' and described by 5746 `pass_linear_transform'. 5747 5748 * Removal of empty loops 5749 5750 This pass removes loops with no code in them. The pass is located 5751 in `tree-ssa-loop-ivcanon.c' and described by `pass_empty_loop'. 5752 5753 * Unrolling of small loops 5754 5755 This pass completely unrolls loops with few iterations. The pass 5756 is located in `tree-ssa-loop-ivcanon.c' and described by 5757 `pass_complete_unroll'. 5758 5759 * Predictive commoning 5760 5761 This pass makes the code reuse the computations from the previous 5762 iterations of the loops, especially loads and stores to memory. 5763 It does so by storing the values of these computations to a bank 5764 of temporary variables that are rotated at the end of loop. To 5765 avoid the need for this rotation, the loop is then unrolled and 5766 the copies of the loop body are rewritten to use the appropriate 5767 version of the temporary variable. This pass is located in 5768 `tree-predcom.c' and described by `pass_predcom'. 5769 5770 * Array prefetching 5771 5772 This pass issues prefetch instructions for array references inside 5773 loops. The pass is located in `tree-ssa-loop-prefetch.c' and 5774 described by `pass_loop_prefetch'. 5775 5776 * Reassociation 5777 5778 This pass rewrites arithmetic expressions to enable optimizations 5779 that operate on them, like redundancy elimination and 5780 vectorization. The pass is located in `tree-ssa-reassoc.c' and 5781 described by `pass_reassoc'. 5782 5783 * Optimization of `stdarg' functions 5784 5785 This pass tries to avoid the saving of register arguments into the 5786 stack on entry to `stdarg' functions. If the function doesn't use 5787 any `va_start' macros, no registers need to be saved. If 5788 `va_start' macros are used, the `va_list' variables don't escape 5789 the function, it is only necessary to save registers that will be 5790 used in `va_arg' macros. For instance, if `va_arg' is only used 5791 with integral types in the function, floating point registers 5792 don't need to be saved. This pass is located in `tree-stdarg.c' 5793 and described by `pass_stdarg'. 5794 5795 5796 5797 File: gccint.info, Node: RTL passes, Prev: Tree-SSA passes, Up: Passes 5798 5799 8.5 RTL passes 5800 ============== 5801 5802 The following briefly describes the rtl generation and optimization 5803 passes that are run after tree optimization. 5804 5805 * RTL generation 5806 5807 The source files for RTL generation include `stmt.c', `calls.c', 5808 `expr.c', `explow.c', `expmed.c', `function.c', `optabs.c' and 5809 `emit-rtl.c'. Also, the file `insn-emit.c', generated from the 5810 machine description by the program `genemit', is used in this 5811 pass. The header file `expr.h' is used for communication within 5812 this pass. 5813 5814 The header files `insn-flags.h' and `insn-codes.h', generated from 5815 the machine description by the programs `genflags' and `gencodes', 5816 tell this pass which standard names are available for use and 5817 which patterns correspond to them. 5818 5819 * Generate exception handling landing pads 5820 5821 This pass generates the glue that handles communication between the 5822 exception handling library routines and the exception handlers 5823 within the function. Entry points in the function that are 5824 invoked by the exception handling library are called "landing 5825 pads". The code for this pass is located within `except.c'. 5826 5827 * Cleanup control flow graph 5828 5829 This pass removes unreachable code, simplifies jumps to next, 5830 jumps to jump, jumps across jumps, etc. The pass is run multiple 5831 times. For historical reasons, it is occasionally referred to as 5832 the "jump optimization pass". The bulk of the code for this pass 5833 is in `cfgcleanup.c', and there are support routines in `cfgrtl.c' 5834 and `jump.c'. 5835 5836 * Forward propagation of single-def values 5837 5838 This pass attempts to remove redundant computation by substituting 5839 variables that come from a single definition, and seeing if the 5840 result can be simplified. It performs copy propagation and 5841 addressing mode selection. The pass is run twice, with values 5842 being propagated into loops only on the second run. It is located 5843 in `fwprop.c'. 5844 5845 * Common subexpression elimination 5846 5847 This pass removes redundant computation within basic blocks, and 5848 optimizes addressing modes based on cost. The pass is run twice. 5849 The source is located in `cse.c'. 5850 5851 * Global common subexpression elimination. 5852 5853 This pass performs two different types of GCSE depending on 5854 whether you are optimizing for size or not (LCM based GCSE tends 5855 to increase code size for a gain in speed, while Morel-Renvoise 5856 based GCSE does not). When optimizing for size, GCSE is done 5857 using Morel-Renvoise Partial Redundancy Elimination, with the 5858 exception that it does not try to move invariants out of 5859 loops--that is left to the loop optimization pass. If MR PRE 5860 GCSE is done, code hoisting (aka unification) is also done, as 5861 well as load motion. If you are optimizing for speed, LCM (lazy 5862 code motion) based GCSE is done. LCM is based on the work of 5863 Knoop, Ruthing, and Steffen. LCM based GCSE also does loop 5864 invariant code motion. We also perform load and store motion when 5865 optimizing for speed. Regardless of which type of GCSE is used, 5866 the GCSE pass also performs global constant and copy propagation. 5867 The source file for this pass is `gcse.c', and the LCM routines 5868 are in `lcm.c'. 5869 5870 * Loop optimization 5871 5872 This pass performs several loop related optimizations. The source 5873 files `cfgloopanal.c' and `cfgloopmanip.c' contain generic loop 5874 analysis and manipulation code. Initialization and finalization 5875 of loop structures is handled by `loop-init.c'. A loop invariant 5876 motion pass is implemented in `loop-invariant.c'. Basic block 5877 level optimizations--unrolling, peeling and unswitching loops-- 5878 are implemented in `loop-unswitch.c' and `loop-unroll.c'. 5879 Replacing of the exit condition of loops by special 5880 machine-dependent instructions is handled by `loop-doloop.c'. 5881 5882 * Jump bypassing 5883 5884 This pass is an aggressive form of GCSE that transforms the control 5885 flow graph of a function by propagating constants into conditional 5886 branch instructions. The source file for this pass is `gcse.c'. 5887 5888 * If conversion 5889 5890 This pass attempts to replace conditional branches and surrounding 5891 assignments with arithmetic, boolean value producing comparison 5892 instructions, and conditional move instructions. In the very last 5893 invocation after reload, it will generate predicated instructions 5894 when supported by the target. The pass is located in `ifcvt.c'. 5895 5896 * Web construction 5897 5898 This pass splits independent uses of each pseudo-register. This 5899 can improve effect of the other transformation, such as CSE or 5900 register allocation. Its source files are `web.c'. 5901 5902 * Life analysis 5903 5904 This pass computes which pseudo-registers are live at each point in 5905 the program, and makes the first instruction that uses a value 5906 point at the instruction that computed the value. It then deletes 5907 computations whose results are never used, and combines memory 5908 references with add or subtract instructions to make autoincrement 5909 or autodecrement addressing. The pass is located in `flow.c'. 5910 5911 * Instruction combination 5912 5913 This pass attempts to combine groups of two or three instructions 5914 that are related by data flow into single instructions. It 5915 combines the RTL expressions for the instructions by substitution, 5916 simplifies the result using algebra, and then attempts to match 5917 the result against the machine description. The pass is located 5918 in `combine.c'. 5919 5920 * Register movement 5921 5922 This pass looks for cases where matching constraints would force an 5923 instruction to need a reload, and this reload would be a 5924 register-to-register move. It then attempts to change the 5925 registers used by the instruction to avoid the move instruction. 5926 The pass is located in `regmove.c'. 5927 5928 * Optimize mode switching 5929 5930 This pass looks for instructions that require the processor to be 5931 in a specific "mode" and minimizes the number of mode changes 5932 required to satisfy all users. What these modes are, and what 5933 they apply to are completely target-specific. The source is 5934 located in `mode-switching.c'. 5935 5936 * Modulo scheduling 5937 5938 This pass looks at innermost loops and reorders their instructions 5939 by overlapping different iterations. Modulo scheduling is 5940 performed immediately before instruction scheduling. The pass is 5941 located in (`modulo-sched.c'). 5942 5943 * Instruction scheduling 5944 5945 This pass looks for instructions whose output will not be 5946 available by the time that it is used in subsequent instructions. 5947 Memory loads and floating point instructions often have this 5948 behavior on RISC machines. It re-orders instructions within a 5949 basic block to try to separate the definition and use of items 5950 that otherwise would cause pipeline stalls. This pass is 5951 performed twice, before and after register allocation. The pass 5952 is located in `haifa-sched.c', `sched-deps.c', `sched-ebb.c', 5953 `sched-rgn.c' and `sched-vis.c'. 5954 5955 * Register allocation 5956 5957 These passes make sure that all occurrences of pseudo registers are 5958 eliminated, either by allocating them to a hard register, replacing 5959 them by an equivalent expression (e.g. a constant) or by placing 5960 them on the stack. This is done in several subpasses: 5961 5962 * Register move optimizations. This pass makes some simple RTL 5963 code transformations which improve the subsequent register 5964 allocation. The source file is `regmove.c'. 5965 5966 * The integrated register allocator (IRA). It is called 5967 integrated because coalescing, register live range splitting, 5968 and hard register preferencing are done on-the-fly during 5969 coloring. It also has better integration with the reload 5970 pass. Pseudo-registers spilled by the allocator or the 5971 reload have still a chance to get hard-registers if the 5972 reload evicts some pseudo-registers from hard-registers. The 5973 allocator helps to choose better pseudos for spilling based 5974 on their live ranges and to coalesce stack slots allocated 5975 for the spilled pseudo-registers. IRA is a regional register 5976 allocator which is transformed into Chaitin-Briggs allocator 5977 if there is one region. By default, IRA chooses regions using 5978 register pressure but the user can force it to use one region 5979 or regions corresponding to all loops. 5980 5981 Source files of the allocator are `ira.c', `ira-build.c', 5982 `ira-costs.c', `ira-conflicts.c', `ira-color.c', 5983 `ira-emit.c', `ira-lives', plus header files `ira.h' and 5984 `ira-int.h' used for the communication between the allocator 5985 and the rest of the compiler and between the IRA files. 5986 5987 * Reloading. This pass renumbers pseudo registers with the 5988 hardware registers numbers they were allocated. Pseudo 5989 registers that did not get hard registers are replaced with 5990 stack slots. Then it finds instructions that are invalid 5991 because a value has failed to end up in a register, or has 5992 ended up in a register of the wrong kind. It fixes up these 5993 instructions by reloading the problematical values 5994 temporarily into registers. Additional instructions are 5995 generated to do the copying. 5996 5997 The reload pass also optionally eliminates the frame pointer 5998 and inserts instructions to save and restore call-clobbered 5999 registers around calls. 6000 6001 Source files are `reload.c' and `reload1.c', plus the header 6002 `reload.h' used for communication between them. 6003 6004 * Basic block reordering 6005 6006 This pass implements profile guided code positioning. If profile 6007 information is not available, various types of static analysis are 6008 performed to make the predictions normally coming from the profile 6009 feedback (IE execution frequency, branch probability, etc). It is 6010 implemented in the file `bb-reorder.c', and the various prediction 6011 routines are in `predict.c'. 6012 6013 * Variable tracking 6014 6015 This pass computes where the variables are stored at each position 6016 in code and generates notes describing the variable locations to 6017 RTL code. The location lists are then generated according to these 6018 notes to debug information if the debugging information format 6019 supports location lists. 6020 6021 * Delayed branch scheduling 6022 6023 This optional pass attempts to find instructions that can go into 6024 the delay slots of other instructions, usually jumps and calls. 6025 The source file name is `reorg.c'. 6026 6027 * Branch shortening 6028 6029 On many RISC machines, branch instructions have a limited range. 6030 Thus, longer sequences of instructions must be used for long 6031 branches. In this pass, the compiler figures out what how far 6032 each instruction will be from each other instruction, and 6033 therefore whether the usual instructions, or the longer sequences, 6034 must be used for each branch. 6035 6036 * Register-to-stack conversion 6037 6038 Conversion from usage of some hard registers to usage of a register 6039 stack may be done at this point. Currently, this is supported only 6040 for the floating-point registers of the Intel 80387 coprocessor. 6041 The source file name is `reg-stack.c'. 6042 6043 * Final 6044 6045 This pass outputs the assembler code for the function. The source 6046 files are `final.c' plus `insn-output.c'; the latter is generated 6047 automatically from the machine description by the tool `genoutput'. 6048 The header file `conditions.h' is used for communication between 6049 these files. If mudflap is enabled, the queue of deferred 6050 declarations and any addressed constants (e.g., string literals) 6051 is processed by `mudflap_finish_file' into a synthetic constructor 6052 function containing calls into the mudflap runtime. 6053 6054 * Debugging information output 6055 6056 This is run after final because it must output the stack slot 6057 offsets for pseudo registers that did not get hard registers. 6058 Source files are `dbxout.c' for DBX symbol table format, 6059 `sdbout.c' for SDB symbol table format, `dwarfout.c' for DWARF 6060 symbol table format, files `dwarf2out.c' and `dwarf2asm.c' for 6061 DWARF2 symbol table format, and `vmsdbgout.c' for VMS debug symbol 6062 table format. 6063 6064 6065 6066 File: gccint.info, Node: Trees, Next: RTL, Prev: Passes, Up: Top 6067 6068 9 Trees: The intermediate representation used by the C and C++ front ends 6069 ************************************************************************* 6070 6071 This chapter documents the internal representation used by GCC to 6072 represent C and C++ source programs. When presented with a C or C++ 6073 source program, GCC parses the program, performs semantic analysis 6074 (including the generation of error messages), and then produces the 6075 internal representation described here. This representation contains a 6076 complete representation for the entire translation unit provided as 6077 input to the front end. This representation is then typically processed 6078 by a code-generator in order to produce machine code, but could also be 6079 used in the creation of source browsers, intelligent editors, automatic 6080 documentation generators, interpreters, and any other programs needing 6081 the ability to process C or C++ code. 6082 6083 This chapter explains the internal representation. In particular, it 6084 documents the internal representation for C and C++ source constructs, 6085 and the macros, functions, and variables that can be used to access 6086 these constructs. The C++ representation is largely a superset of the 6087 representation used in the C front end. There is only one construct 6088 used in C that does not appear in the C++ front end and that is the GNU 6089 "nested function" extension. Many of the macros documented here do not 6090 apply in C because the corresponding language constructs do not appear 6091 in C. 6092 6093 If you are developing a "back end", be it is a code-generator or some 6094 other tool, that uses this representation, you may occasionally find 6095 that you need to ask questions not easily answered by the functions and 6096 macros available here. If that situation occurs, it is quite likely 6097 that GCC already supports the functionality you desire, but that the 6098 interface is simply not documented here. In that case, you should ask 6099 the GCC maintainers (via mail to <gcc (a] gcc.gnu.org>) about documenting 6100 the functionality you require. Similarly, if you find yourself writing 6101 functions that do not deal directly with your back end, but instead 6102 might be useful to other people using the GCC front end, you should 6103 submit your patches for inclusion in GCC. 6104 6105 * Menu: 6106 6107 * Deficiencies:: Topics net yet covered in this document. 6108 * Tree overview:: All about `tree's. 6109 * Types:: Fundamental and aggregate types. 6110 * Scopes:: Namespaces and classes. 6111 * Functions:: Overloading, function bodies, and linkage. 6112 * Declarations:: Type declarations and variables. 6113 * Attributes:: Declaration and type attributes. 6114 * Expression trees:: From `typeid' to `throw'. 6115 6116 6117 File: gccint.info, Node: Deficiencies, Next: Tree overview, Up: Trees 6118 6119 9.1 Deficiencies 6120 ================ 6121 6122 There are many places in which this document is incomplet and incorrekt. 6123 It is, as of yet, only _preliminary_ documentation. 6124 6125 6126 File: gccint.info, Node: Tree overview, Next: Types, Prev: Deficiencies, Up: Trees 6127 6128 9.2 Overview 6129 ============ 6130 6131 The central data structure used by the internal representation is the 6132 `tree'. These nodes, while all of the C type `tree', are of many 6133 varieties. A `tree' is a pointer type, but the object to which it 6134 points may be of a variety of types. From this point forward, we will 6135 refer to trees in ordinary type, rather than in `this font', except 6136 when talking about the actual C type `tree'. 6137 6138 You can tell what kind of node a particular tree is by using the 6139 `TREE_CODE' macro. Many, many macros take trees as input and return 6140 trees as output. However, most macros require a certain kind of tree 6141 node as input. In other words, there is a type-system for trees, but 6142 it is not reflected in the C type-system. 6143 6144 For safety, it is useful to configure GCC with `--enable-checking'. 6145 Although this results in a significant performance penalty (since all 6146 tree types are checked at run-time), and is therefore inappropriate in a 6147 release version, it is extremely helpful during the development process. 6148 6149 Many macros behave as predicates. Many, although not all, of these 6150 predicates end in `_P'. Do not rely on the result type of these macros 6151 being of any particular type. You may, however, rely on the fact that 6152 the type can be compared to `0', so that statements like 6153 if (TEST_P (t) && !TEST_P (y)) 6154 x = 1; 6155 and 6156 int i = (TEST_P (t) != 0); 6157 are legal. Macros that return `int' values now may be changed to 6158 return `tree' values, or other pointers in the future. Even those that 6159 continue to return `int' may return multiple nonzero codes where 6160 previously they returned only zero and one. Therefore, you should not 6161 write code like 6162 if (TEST_P (t) == 1) 6163 as this code is not guaranteed to work correctly in the future. 6164 6165 You should not take the address of values returned by the macros or 6166 functions described here. In particular, no guarantee is given that the 6167 values are lvalues. 6168 6169 In general, the names of macros are all in uppercase, while the names 6170 of functions are entirely in lowercase. There are rare exceptions to 6171 this rule. You should assume that any macro or function whose name is 6172 made up entirely of uppercase letters may evaluate its arguments more 6173 than once. You may assume that a macro or function whose name is made 6174 up entirely of lowercase letters will evaluate its arguments only once. 6175 6176 The `error_mark_node' is a special tree. Its tree code is 6177 `ERROR_MARK', but since there is only ever one node with that code, the 6178 usual practice is to compare the tree against `error_mark_node'. (This 6179 test is just a test for pointer equality.) If an error has occurred 6180 during front-end processing the flag `errorcount' will be set. If the 6181 front end has encountered code it cannot handle, it will issue a 6182 message to the user and set `sorrycount'. When these flags are set, 6183 any macro or function which normally returns a tree of a particular 6184 kind may instead return the `error_mark_node'. Thus, if you intend to 6185 do any processing of erroneous code, you must be prepared to deal with 6186 the `error_mark_node'. 6187 6188 Occasionally, a particular tree slot (like an operand to an expression, 6189 or a particular field in a declaration) will be referred to as 6190 "reserved for the back end". These slots are used to store RTL when 6191 the tree is converted to RTL for use by the GCC back end. However, if 6192 that process is not taking place (e.g., if the front end is being hooked 6193 up to an intelligent editor), then those slots may be used by the back 6194 end presently in use. 6195 6196 If you encounter situations that do not match this documentation, such 6197 as tree nodes of types not mentioned here, or macros documented to 6198 return entities of a particular kind that instead return entities of 6199 some different kind, you have found a bug, either in the front end or in 6200 the documentation. Please report these bugs as you would any other bug. 6201 6202 * Menu: 6203 6204 * Macros and Functions::Macros and functions that can be used with all trees. 6205 * Identifiers:: The names of things. 6206 * Containers:: Lists and vectors. 6207 6208 6209 File: gccint.info, Node: Macros and Functions, Next: Identifiers, Up: Tree overview 6210 6211 9.2.1 Trees 6212 ----------- 6213 6214 This section is not here yet. 6215 6216 6217 File: gccint.info, Node: Identifiers, Next: Containers, Prev: Macros and Functions, Up: Tree overview 6218 6219 9.2.2 Identifiers 6220 ----------------- 6221 6222 An `IDENTIFIER_NODE' represents a slightly more general concept that 6223 the standard C or C++ concept of identifier. In particular, an 6224 `IDENTIFIER_NODE' may contain a `$', or other extraordinary characters. 6225 6226 There are never two distinct `IDENTIFIER_NODE's representing the same 6227 identifier. Therefore, you may use pointer equality to compare 6228 `IDENTIFIER_NODE's, rather than using a routine like `strcmp'. 6229 6230 You can use the following macros to access identifiers: 6231 `IDENTIFIER_POINTER' 6232 The string represented by the identifier, represented as a 6233 `char*'. This string is always `NUL'-terminated, and contains no 6234 embedded `NUL' characters. 6235 6236 `IDENTIFIER_LENGTH' 6237 The length of the string returned by `IDENTIFIER_POINTER', not 6238 including the trailing `NUL'. This value of `IDENTIFIER_LENGTH 6239 (x)' is always the same as `strlen (IDENTIFIER_POINTER (x))'. 6240 6241 `IDENTIFIER_OPNAME_P' 6242 This predicate holds if the identifier represents the name of an 6243 overloaded operator. In this case, you should not depend on the 6244 contents of either the `IDENTIFIER_POINTER' or the 6245 `IDENTIFIER_LENGTH'. 6246 6247 `IDENTIFIER_TYPENAME_P' 6248 This predicate holds if the identifier represents the name of a 6249 user-defined conversion operator. In this case, the `TREE_TYPE' of 6250 the `IDENTIFIER_NODE' holds the type to which the conversion 6251 operator converts. 6252 6253 6254 6255 File: gccint.info, Node: Containers, Prev: Identifiers, Up: Tree overview 6256 6257 9.2.3 Containers 6258 ---------------- 6259 6260 Two common container data structures can be represented directly with 6261 tree nodes. A `TREE_LIST' is a singly linked list containing two trees 6262 per node. These are the `TREE_PURPOSE' and `TREE_VALUE' of each node. 6263 (Often, the `TREE_PURPOSE' contains some kind of tag, or additional 6264 information, while the `TREE_VALUE' contains the majority of the 6265 payload. In other cases, the `TREE_PURPOSE' is simply `NULL_TREE', 6266 while in still others both the `TREE_PURPOSE' and `TREE_VALUE' are of 6267 equal stature.) Given one `TREE_LIST' node, the next node is found by 6268 following the `TREE_CHAIN'. If the `TREE_CHAIN' is `NULL_TREE', then 6269 you have reached the end of the list. 6270 6271 A `TREE_VEC' is a simple vector. The `TREE_VEC_LENGTH' is an integer 6272 (not a tree) giving the number of nodes in the vector. The nodes 6273 themselves are accessed using the `TREE_VEC_ELT' macro, which takes two 6274 arguments. The first is the `TREE_VEC' in question; the second is an 6275 integer indicating which element in the vector is desired. The 6276 elements are indexed from zero. 6277 6278 6279 File: gccint.info, Node: Types, Next: Scopes, Prev: Tree overview, Up: Trees 6280 6281 9.3 Types 6282 ========= 6283 6284 All types have corresponding tree nodes. However, you should not assume 6285 that there is exactly one tree node corresponding to each type. There 6286 are often multiple nodes corresponding to the same type. 6287 6288 For the most part, different kinds of types have different tree codes. 6289 (For example, pointer types use a `POINTER_TYPE' code while arrays use 6290 an `ARRAY_TYPE' code.) However, pointers to member functions use the 6291 `RECORD_TYPE' code. Therefore, when writing a `switch' statement that 6292 depends on the code associated with a particular type, you should take 6293 care to handle pointers to member functions under the `RECORD_TYPE' 6294 case label. 6295 6296 In C++, an array type is not qualified; rather the type of the array 6297 elements is qualified. This situation is reflected in the intermediate 6298 representation. The macros described here will always examine the 6299 qualification of the underlying element type when applied to an array 6300 type. (If the element type is itself an array, then the recursion 6301 continues until a non-array type is found, and the qualification of this 6302 type is examined.) So, for example, `CP_TYPE_CONST_P' will hold of the 6303 type `const int ()[7]', denoting an array of seven `int's. 6304 6305 The following functions and macros deal with cv-qualification of types: 6306 `CP_TYPE_QUALS' 6307 This macro returns the set of type qualifiers applied to this type. 6308 This value is `TYPE_UNQUALIFIED' if no qualifiers have been 6309 applied. The `TYPE_QUAL_CONST' bit is set if the type is 6310 `const'-qualified. The `TYPE_QUAL_VOLATILE' bit is set if the 6311 type is `volatile'-qualified. The `TYPE_QUAL_RESTRICT' bit is set 6312 if the type is `restrict'-qualified. 6313 6314 `CP_TYPE_CONST_P' 6315 This macro holds if the type is `const'-qualified. 6316 6317 `CP_TYPE_VOLATILE_P' 6318 This macro holds if the type is `volatile'-qualified. 6319 6320 `CP_TYPE_RESTRICT_P' 6321 This macro holds if the type is `restrict'-qualified. 6322 6323 `CP_TYPE_CONST_NON_VOLATILE_P' 6324 This predicate holds for a type that is `const'-qualified, but 6325 _not_ `volatile'-qualified; other cv-qualifiers are ignored as 6326 well: only the `const'-ness is tested. 6327 6328 `TYPE_MAIN_VARIANT' 6329 This macro returns the unqualified version of a type. It may be 6330 applied to an unqualified type, but it is not always the identity 6331 function in that case. 6332 6333 A few other macros and functions are usable with all types: 6334 `TYPE_SIZE' 6335 The number of bits required to represent the type, represented as 6336 an `INTEGER_CST'. For an incomplete type, `TYPE_SIZE' will be 6337 `NULL_TREE'. 6338 6339 `TYPE_ALIGN' 6340 The alignment of the type, in bits, represented as an `int'. 6341 6342 `TYPE_NAME' 6343 This macro returns a declaration (in the form of a `TYPE_DECL') for 6344 the type. (Note this macro does _not_ return a `IDENTIFIER_NODE', 6345 as you might expect, given its name!) You can look at the 6346 `DECL_NAME' of the `TYPE_DECL' to obtain the actual name of the 6347 type. The `TYPE_NAME' will be `NULL_TREE' for a type that is not 6348 a built-in type, the result of a typedef, or a named class type. 6349 6350 `CP_INTEGRAL_TYPE' 6351 This predicate holds if the type is an integral type. Notice that 6352 in C++, enumerations are _not_ integral types. 6353 6354 `ARITHMETIC_TYPE_P' 6355 This predicate holds if the type is an integral type (in the C++ 6356 sense) or a floating point type. 6357 6358 `CLASS_TYPE_P' 6359 This predicate holds for a class-type. 6360 6361 `TYPE_BUILT_IN' 6362 This predicate holds for a built-in type. 6363 6364 `TYPE_PTRMEM_P' 6365 This predicate holds if the type is a pointer to data member. 6366 6367 `TYPE_PTR_P' 6368 This predicate holds if the type is a pointer type, and the 6369 pointee is not a data member. 6370 6371 `TYPE_PTRFN_P' 6372 This predicate holds for a pointer to function type. 6373 6374 `TYPE_PTROB_P' 6375 This predicate holds for a pointer to object type. Note however 6376 that it does not hold for the generic pointer to object type `void 6377 *'. You may use `TYPE_PTROBV_P' to test for a pointer to object 6378 type as well as `void *'. 6379 6380 `TYPE_CANONICAL' 6381 This macro returns the "canonical" type for the given type node. 6382 Canonical types are used to improve performance in the C++ and 6383 Objective-C++ front ends by allowing efficient comparison between 6384 two type nodes in `same_type_p': if the `TYPE_CANONICAL' values of 6385 the types are equal, the types are equivalent; otherwise, the types 6386 are not equivalent. The notion of equivalence for canonical types 6387 is the same as the notion of type equivalence in the language 6388 itself. For instance, 6389 6390 When `TYPE_CANONICAL' is `NULL_TREE', there is no canonical type 6391 for the given type node. In this case, comparison between this 6392 type and any other type requires the compiler to perform a deep, 6393 "structural" comparison to see if the two type nodes have the same 6394 form and properties. 6395 6396 The canonical type for a node is always the most fundamental type 6397 in the equivalence class of types. For instance, `int' is its own 6398 canonical type. A typedef `I' of `int' will have `int' as its 6399 canonical type. Similarly, `I*' and a typedef `IP' (defined to 6400 `I*') will has `int*' as their canonical type. When building a new 6401 type node, be sure to set `TYPE_CANONICAL' to the appropriate 6402 canonical type. If the new type is a compound type (built from 6403 other types), and any of those other types require structural 6404 equality, use `SET_TYPE_STRUCTURAL_EQUALITY' to ensure that the 6405 new type also requires structural equality. Finally, if for some 6406 reason you cannot guarantee that `TYPE_CANONICAL' will point to 6407 the canonical type, use `SET_TYPE_STRUCTURAL_EQUALITY' to make 6408 sure that the new type-and any type constructed based on 6409 it-requires structural equality. If you suspect that the canonical 6410 type system is miscomparing types, pass `--param 6411 verify-canonical-types=1' to the compiler or configure with 6412 `--enable-checking' to force the compiler to verify its 6413 canonical-type comparisons against the structural comparisons; the 6414 compiler will then print any warnings if the canonical types 6415 miscompare. 6416 6417 `TYPE_STRUCTURAL_EQUALITY_P' 6418 This predicate holds when the node requires structural equality 6419 checks, e.g., when `TYPE_CANONICAL' is `NULL_TREE'. 6420 6421 `SET_TYPE_STRUCTURAL_EQUALITY' 6422 This macro states that the type node it is given requires 6423 structural equality checks, e.g., it sets `TYPE_CANONICAL' to 6424 `NULL_TREE'. 6425 6426 `same_type_p' 6427 This predicate takes two types as input, and holds if they are the 6428 same type. For example, if one type is a `typedef' for the other, 6429 or both are `typedef's for the same type. This predicate also 6430 holds if the two trees given as input are simply copies of one 6431 another; i.e., there is no difference between them at the source 6432 level, but, for whatever reason, a duplicate has been made in the 6433 representation. You should never use `==' (pointer equality) to 6434 compare types; always use `same_type_p' instead. 6435 6436 Detailed below are the various kinds of types, and the macros that can 6437 be used to access them. Although other kinds of types are used 6438 elsewhere in G++, the types described here are the only ones that you 6439 will encounter while examining the intermediate representation. 6440 6441 `VOID_TYPE' 6442 Used to represent the `void' type. 6443 6444 `INTEGER_TYPE' 6445 Used to represent the various integral types, including `char', 6446 `short', `int', `long', and `long long'. This code is not used 6447 for enumeration types, nor for the `bool' type. The 6448 `TYPE_PRECISION' is the number of bits used in the representation, 6449 represented as an `unsigned int'. (Note that in the general case 6450 this is not the same value as `TYPE_SIZE'; suppose that there were 6451 a 24-bit integer type, but that alignment requirements for the ABI 6452 required 32-bit alignment. Then, `TYPE_SIZE' would be an 6453 `INTEGER_CST' for 32, while `TYPE_PRECISION' would be 24.) The 6454 integer type is unsigned if `TYPE_UNSIGNED' holds; otherwise, it 6455 is signed. 6456 6457 The `TYPE_MIN_VALUE' is an `INTEGER_CST' for the smallest integer 6458 that may be represented by this type. Similarly, the 6459 `TYPE_MAX_VALUE' is an `INTEGER_CST' for the largest integer that 6460 may be represented by this type. 6461 6462 `REAL_TYPE' 6463 Used to represent the `float', `double', and `long double' types. 6464 The number of bits in the floating-point representation is given 6465 by `TYPE_PRECISION', as in the `INTEGER_TYPE' case. 6466 6467 `FIXED_POINT_TYPE' 6468 Used to represent the `short _Fract', `_Fract', `long _Fract', 6469 `long long _Fract', `short _Accum', `_Accum', `long _Accum', and 6470 `long long _Accum' types. The number of bits in the fixed-point 6471 representation is given by `TYPE_PRECISION', as in the 6472 `INTEGER_TYPE' case. There may be padding bits, fractional bits 6473 and integral bits. The number of fractional bits is given by 6474 `TYPE_FBIT', and the number of integral bits is given by 6475 `TYPE_IBIT'. The fixed-point type is unsigned if `TYPE_UNSIGNED' 6476 holds; otherwise, it is signed. The fixed-point type is 6477 saturating if `TYPE_SATURATING' holds; otherwise, it is not 6478 saturating. 6479 6480 `COMPLEX_TYPE' 6481 Used to represent GCC built-in `__complex__' data types. The 6482 `TREE_TYPE' is the type of the real and imaginary parts. 6483 6484 `ENUMERAL_TYPE' 6485 Used to represent an enumeration type. The `TYPE_PRECISION' gives 6486 (as an `int'), the number of bits used to represent the type. If 6487 there are no negative enumeration constants, `TYPE_UNSIGNED' will 6488 hold. The minimum and maximum enumeration constants may be 6489 obtained with `TYPE_MIN_VALUE' and `TYPE_MAX_VALUE', respectively; 6490 each of these macros returns an `INTEGER_CST'. 6491 6492 The actual enumeration constants themselves may be obtained by 6493 looking at the `TYPE_VALUES'. This macro will return a 6494 `TREE_LIST', containing the constants. The `TREE_PURPOSE' of each 6495 node will be an `IDENTIFIER_NODE' giving the name of the constant; 6496 the `TREE_VALUE' will be an `INTEGER_CST' giving the value 6497 assigned to that constant. These constants will appear in the 6498 order in which they were declared. The `TREE_TYPE' of each of 6499 these constants will be the type of enumeration type itself. 6500 6501 `BOOLEAN_TYPE' 6502 Used to represent the `bool' type. 6503 6504 `POINTER_TYPE' 6505 Used to represent pointer types, and pointer to data member types. 6506 The `TREE_TYPE' gives the type to which this type points. If the 6507 type is a pointer to data member type, then `TYPE_PTRMEM_P' will 6508 hold. For a pointer to data member type of the form `T X::*', 6509 `TYPE_PTRMEM_CLASS_TYPE' will be the type `X', while 6510 `TYPE_PTRMEM_POINTED_TO_TYPE' will be the type `T'. 6511 6512 `REFERENCE_TYPE' 6513 Used to represent reference types. The `TREE_TYPE' gives the type 6514 to which this type refers. 6515 6516 `FUNCTION_TYPE' 6517 Used to represent the type of non-member functions and of static 6518 member functions. The `TREE_TYPE' gives the return type of the 6519 function. The `TYPE_ARG_TYPES' are a `TREE_LIST' of the argument 6520 types. The `TREE_VALUE' of each node in this list is the type of 6521 the corresponding argument; the `TREE_PURPOSE' is an expression 6522 for the default argument value, if any. If the last node in the 6523 list is `void_list_node' (a `TREE_LIST' node whose `TREE_VALUE' is 6524 the `void_type_node'), then functions of this type do not take 6525 variable arguments. Otherwise, they do take a variable number of 6526 arguments. 6527 6528 Note that in C (but not in C++) a function declared like `void f()' 6529 is an unprototyped function taking a variable number of arguments; 6530 the `TYPE_ARG_TYPES' of such a function will be `NULL'. 6531 6532 `METHOD_TYPE' 6533 Used to represent the type of a non-static member function. Like a 6534 `FUNCTION_TYPE', the return type is given by the `TREE_TYPE'. The 6535 type of `*this', i.e., the class of which functions of this type 6536 are a member, is given by the `TYPE_METHOD_BASETYPE'. The 6537 `TYPE_ARG_TYPES' is the parameter list, as for a `FUNCTION_TYPE', 6538 and includes the `this' argument. 6539 6540 `ARRAY_TYPE' 6541 Used to represent array types. The `TREE_TYPE' gives the type of 6542 the elements in the array. If the array-bound is present in the 6543 type, the `TYPE_DOMAIN' is an `INTEGER_TYPE' whose 6544 `TYPE_MIN_VALUE' and `TYPE_MAX_VALUE' will be the lower and upper 6545 bounds of the array, respectively. The `TYPE_MIN_VALUE' will 6546 always be an `INTEGER_CST' for zero, while the `TYPE_MAX_VALUE' 6547 will be one less than the number of elements in the array, i.e., 6548 the highest value which may be used to index an element in the 6549 array. 6550 6551 `RECORD_TYPE' 6552 Used to represent `struct' and `class' types, as well as pointers 6553 to member functions and similar constructs in other languages. 6554 `TYPE_FIELDS' contains the items contained in this type, each of 6555 which can be a `FIELD_DECL', `VAR_DECL', `CONST_DECL', or 6556 `TYPE_DECL'. You may not make any assumptions about the ordering 6557 of the fields in the type or whether one or more of them overlap. 6558 If `TYPE_PTRMEMFUNC_P' holds, then this type is a pointer-to-member 6559 type. In that case, the `TYPE_PTRMEMFUNC_FN_TYPE' is a 6560 `POINTER_TYPE' pointing to a `METHOD_TYPE'. The `METHOD_TYPE' is 6561 the type of a function pointed to by the pointer-to-member 6562 function. If `TYPE_PTRMEMFUNC_P' does not hold, this type is a 6563 class type. For more information, see *note Classes::. 6564 6565 `UNION_TYPE' 6566 Used to represent `union' types. Similar to `RECORD_TYPE' except 6567 that all `FIELD_DECL' nodes in `TYPE_FIELD' start at bit position 6568 zero. 6569 6570 `QUAL_UNION_TYPE' 6571 Used to represent part of a variant record in Ada. Similar to 6572 `UNION_TYPE' except that each `FIELD_DECL' has a `DECL_QUALIFIER' 6573 field, which contains a boolean expression that indicates whether 6574 the field is present in the object. The type will only have one 6575 field, so each field's `DECL_QUALIFIER' is only evaluated if none 6576 of the expressions in the previous fields in `TYPE_FIELDS' are 6577 nonzero. Normally these expressions will reference a field in the 6578 outer object using a `PLACEHOLDER_EXPR'. 6579 6580 `UNKNOWN_TYPE' 6581 This node is used to represent a type the knowledge of which is 6582 insufficient for a sound processing. 6583 6584 `OFFSET_TYPE' 6585 This node is used to represent a pointer-to-data member. For a 6586 data member `X::m' the `TYPE_OFFSET_BASETYPE' is `X' and the 6587 `TREE_TYPE' is the type of `m'. 6588 6589 `TYPENAME_TYPE' 6590 Used to represent a construct of the form `typename T::A'. The 6591 `TYPE_CONTEXT' is `T'; the `TYPE_NAME' is an `IDENTIFIER_NODE' for 6592 `A'. If the type is specified via a template-id, then 6593 `TYPENAME_TYPE_FULLNAME' yields a `TEMPLATE_ID_EXPR'. The 6594 `TREE_TYPE' is non-`NULL' if the node is implicitly generated in 6595 support for the implicit typename extension; in which case the 6596 `TREE_TYPE' is a type node for the base-class. 6597 6598 `TYPEOF_TYPE' 6599 Used to represent the `__typeof__' extension. The `TYPE_FIELDS' 6600 is the expression the type of which is being represented. 6601 6602 There are variables whose values represent some of the basic types. 6603 These include: 6604 `void_type_node' 6605 A node for `void'. 6606 6607 `integer_type_node' 6608 A node for `int'. 6609 6610 `unsigned_type_node.' 6611 A node for `unsigned int'. 6612 6613 `char_type_node.' 6614 A node for `char'. 6615 It may sometimes be useful to compare one of these variables with a 6616 type in hand, using `same_type_p'. 6617 6618 6619 File: gccint.info, Node: Scopes, Next: Functions, Prev: Types, Up: Trees 6620 6621 9.4 Scopes 6622 ========== 6623 6624 The root of the entire intermediate representation is the variable 6625 `global_namespace'. This is the namespace specified with `::' in C++ 6626 source code. All other namespaces, types, variables, functions, and so 6627 forth can be found starting with this namespace. 6628 6629 Besides namespaces, the other high-level scoping construct in C++ is 6630 the class. (Throughout this manual the term "class" is used to mean the 6631 types referred to in the ANSI/ISO C++ Standard as classes; these include 6632 types defined with the `class', `struct', and `union' keywords.) 6633 6634 * Menu: 6635 6636 * Namespaces:: Member functions, types, etc. 6637 * Classes:: Members, bases, friends, etc. 6638 6639 6640 File: gccint.info, Node: Namespaces, Next: Classes, Up: Scopes 6641 6642 9.4.1 Namespaces 6643 ---------------- 6644 6645 A namespace is represented by a `NAMESPACE_DECL' node. 6646 6647 However, except for the fact that it is distinguished as the root of 6648 the representation, the global namespace is no different from any other 6649 namespace. Thus, in what follows, we describe namespaces generally, 6650 rather than the global namespace in particular. 6651 6652 The following macros and functions can be used on a `NAMESPACE_DECL': 6653 6654 `DECL_NAME' 6655 This macro is used to obtain the `IDENTIFIER_NODE' corresponding to 6656 the unqualified name of the name of the namespace (*note 6657 Identifiers::). The name of the global namespace is `::', even 6658 though in C++ the global namespace is unnamed. However, you 6659 should use comparison with `global_namespace', rather than 6660 `DECL_NAME' to determine whether or not a namespace is the global 6661 one. An unnamed namespace will have a `DECL_NAME' equal to 6662 `anonymous_namespace_name'. Within a single translation unit, all 6663 unnamed namespaces will have the same name. 6664 6665 `DECL_CONTEXT' 6666 This macro returns the enclosing namespace. The `DECL_CONTEXT' for 6667 the `global_namespace' is `NULL_TREE'. 6668 6669 `DECL_NAMESPACE_ALIAS' 6670 If this declaration is for a namespace alias, then 6671 `DECL_NAMESPACE_ALIAS' is the namespace for which this one is an 6672 alias. 6673 6674 Do not attempt to use `cp_namespace_decls' for a namespace which is 6675 an alias. Instead, follow `DECL_NAMESPACE_ALIAS' links until you 6676 reach an ordinary, non-alias, namespace, and call 6677 `cp_namespace_decls' there. 6678 6679 `DECL_NAMESPACE_STD_P' 6680 This predicate holds if the namespace is the special `::std' 6681 namespace. 6682 6683 `cp_namespace_decls' 6684 This function will return the declarations contained in the 6685 namespace, including types, overloaded functions, other 6686 namespaces, and so forth. If there are no declarations, this 6687 function will return `NULL_TREE'. The declarations are connected 6688 through their `TREE_CHAIN' fields. 6689 6690 Although most entries on this list will be declarations, 6691 `TREE_LIST' nodes may also appear. In this case, the `TREE_VALUE' 6692 will be an `OVERLOAD'. The value of the `TREE_PURPOSE' is 6693 unspecified; back ends should ignore this value. As with the 6694 other kinds of declarations returned by `cp_namespace_decls', the 6695 `TREE_CHAIN' will point to the next declaration in this list. 6696 6697 For more information on the kinds of declarations that can occur 6698 on this list, *Note Declarations::. Some declarations will not 6699 appear on this list. In particular, no `FIELD_DECL', 6700 `LABEL_DECL', or `PARM_DECL' nodes will appear here. 6701 6702 This function cannot be used with namespaces that have 6703 `DECL_NAMESPACE_ALIAS' set. 6704 6705 6706 6707 File: gccint.info, Node: Classes, Prev: Namespaces, Up: Scopes 6708 6709 9.4.2 Classes 6710 ------------- 6711 6712 A class type is represented by either a `RECORD_TYPE' or a 6713 `UNION_TYPE'. A class declared with the `union' tag is represented by 6714 a `UNION_TYPE', while classes declared with either the `struct' or the 6715 `class' tag are represented by `RECORD_TYPE's. You can use the 6716 `CLASSTYPE_DECLARED_CLASS' macro to discern whether or not a particular 6717 type is a `class' as opposed to a `struct'. This macro will be true 6718 only for classes declared with the `class' tag. 6719 6720 Almost all non-function members are available on the `TYPE_FIELDS' 6721 list. Given one member, the next can be found by following the 6722 `TREE_CHAIN'. You should not depend in any way on the order in which 6723 fields appear on this list. All nodes on this list will be `DECL' 6724 nodes. A `FIELD_DECL' is used to represent a non-static data member, a 6725 `VAR_DECL' is used to represent a static data member, and a `TYPE_DECL' 6726 is used to represent a type. Note that the `CONST_DECL' for an 6727 enumeration constant will appear on this list, if the enumeration type 6728 was declared in the class. (Of course, the `TYPE_DECL' for the 6729 enumeration type will appear here as well.) There are no entries for 6730 base classes on this list. In particular, there is no `FIELD_DECL' for 6731 the "base-class portion" of an object. 6732 6733 The `TYPE_VFIELD' is a compiler-generated field used to point to 6734 virtual function tables. It may or may not appear on the `TYPE_FIELDS' 6735 list. However, back ends should handle the `TYPE_VFIELD' just like all 6736 the entries on the `TYPE_FIELDS' list. 6737 6738 The function members are available on the `TYPE_METHODS' list. Again, 6739 subsequent members are found by following the `TREE_CHAIN' field. If a 6740 function is overloaded, each of the overloaded functions appears; no 6741 `OVERLOAD' nodes appear on the `TYPE_METHODS' list. Implicitly 6742 declared functions (including default constructors, copy constructors, 6743 assignment operators, and destructors) will appear on this list as well. 6744 6745 Every class has an associated "binfo", which can be obtained with 6746 `TYPE_BINFO'. Binfos are used to represent base-classes. The binfo 6747 given by `TYPE_BINFO' is the degenerate case, whereby every class is 6748 considered to be its own base-class. The base binfos for a particular 6749 binfo are held in a vector, whose length is obtained with 6750 `BINFO_N_BASE_BINFOS'. The base binfos themselves are obtained with 6751 `BINFO_BASE_BINFO' and `BINFO_BASE_ITERATE'. To add a new binfo, use 6752 `BINFO_BASE_APPEND'. The vector of base binfos can be obtained with 6753 `BINFO_BASE_BINFOS', but normally you do not need to use that. The 6754 class type associated with a binfo is given by `BINFO_TYPE'. It is not 6755 always the case that `BINFO_TYPE (TYPE_BINFO (x))', because of typedefs 6756 and qualified types. Neither is it the case that `TYPE_BINFO 6757 (BINFO_TYPE (y))' is the same binfo as `y'. The reason is that if `y' 6758 is a binfo representing a base-class `B' of a derived class `D', then 6759 `BINFO_TYPE (y)' will be `B', and `TYPE_BINFO (BINFO_TYPE (y))' will be 6760 `B' as its own base-class, rather than as a base-class of `D'. 6761 6762 The access to a base type can be found with `BINFO_BASE_ACCESS'. This 6763 will produce `access_public_node', `access_private_node' or 6764 `access_protected_node'. If bases are always public, 6765 `BINFO_BASE_ACCESSES' may be `NULL'. 6766 6767 `BINFO_VIRTUAL_P' is used to specify whether the binfo is inherited 6768 virtually or not. The other flags, `BINFO_MARKED_P' and `BINFO_FLAG_1' 6769 to `BINFO_FLAG_6' can be used for language specific use. 6770 6771 The following macros can be used on a tree node representing a 6772 class-type. 6773 6774 `LOCAL_CLASS_P' 6775 This predicate holds if the class is local class _i.e._ declared 6776 inside a function body. 6777 6778 `TYPE_POLYMORPHIC_P' 6779 This predicate holds if the class has at least one virtual function 6780 (declared or inherited). 6781 6782 `TYPE_HAS_DEFAULT_CONSTRUCTOR' 6783 This predicate holds whenever its argument represents a class-type 6784 with default constructor. 6785 6786 `CLASSTYPE_HAS_MUTABLE' 6787 `TYPE_HAS_MUTABLE_P' 6788 These predicates hold for a class-type having a mutable data 6789 member. 6790 6791 `CLASSTYPE_NON_POD_P' 6792 This predicate holds only for class-types that are not PODs. 6793 6794 `TYPE_HAS_NEW_OPERATOR' 6795 This predicate holds for a class-type that defines `operator new'. 6796 6797 `TYPE_HAS_ARRAY_NEW_OPERATOR' 6798 This predicate holds for a class-type for which `operator new[]' 6799 is defined. 6800 6801 `TYPE_OVERLOADS_CALL_EXPR' 6802 This predicate holds for class-type for which the function call 6803 `operator()' is overloaded. 6804 6805 `TYPE_OVERLOADS_ARRAY_REF' 6806 This predicate holds for a class-type that overloads `operator[]' 6807 6808 `TYPE_OVERLOADS_ARROW' 6809 This predicate holds for a class-type for which `operator->' is 6810 overloaded. 6811 6812 6813 6814 File: gccint.info, Node: Declarations, Next: Attributes, Prev: Functions, Up: Trees 6815 6816 9.5 Declarations 6817 ================ 6818 6819 This section covers the various kinds of declarations that appear in the 6820 internal representation, except for declarations of functions 6821 (represented by `FUNCTION_DECL' nodes), which are described in *Note 6822 Functions::. 6823 6824 * Menu: 6825 6826 * Working with declarations:: Macros and functions that work on 6827 declarations. 6828 * Internal structure:: How declaration nodes are represented. 6829 6830 6831 File: gccint.info, Node: Working with declarations, Next: Internal structure, Up: Declarations 6832 6833 9.5.1 Working with declarations 6834 ------------------------------- 6835 6836 Some macros can be used with any kind of declaration. These include: 6837 `DECL_NAME' 6838 This macro returns an `IDENTIFIER_NODE' giving the name of the 6839 entity. 6840 6841 `TREE_TYPE' 6842 This macro returns the type of the entity declared. 6843 6844 `TREE_FILENAME' 6845 This macro returns the name of the file in which the entity was 6846 declared, as a `char*'. For an entity declared implicitly by the 6847 compiler (like `__builtin_memcpy'), this will be the string 6848 `"<internal>"'. 6849 6850 `TREE_LINENO' 6851 This macro returns the line number at which the entity was 6852 declared, as an `int'. 6853 6854 `DECL_ARTIFICIAL' 6855 This predicate holds if the declaration was implicitly generated 6856 by the compiler. For example, this predicate will hold of an 6857 implicitly declared member function, or of the `TYPE_DECL' 6858 implicitly generated for a class type. Recall that in C++ code 6859 like: 6860 struct S {}; 6861 is roughly equivalent to C code like: 6862 struct S {}; 6863 typedef struct S S; 6864 The implicitly generated `typedef' declaration is represented by a 6865 `TYPE_DECL' for which `DECL_ARTIFICIAL' holds. 6866 6867 `DECL_NAMESPACE_SCOPE_P' 6868 This predicate holds if the entity was declared at a namespace 6869 scope. 6870 6871 `DECL_CLASS_SCOPE_P' 6872 This predicate holds if the entity was declared at a class scope. 6873 6874 `DECL_FUNCTION_SCOPE_P' 6875 This predicate holds if the entity was declared inside a function 6876 body. 6877 6878 6879 The various kinds of declarations include: 6880 `LABEL_DECL' 6881 These nodes are used to represent labels in function bodies. For 6882 more information, see *Note Functions::. These nodes only appear 6883 in block scopes. 6884 6885 `CONST_DECL' 6886 These nodes are used to represent enumeration constants. The 6887 value of the constant is given by `DECL_INITIAL' which will be an 6888 `INTEGER_CST' with the same type as the `TREE_TYPE' of the 6889 `CONST_DECL', i.e., an `ENUMERAL_TYPE'. 6890 6891 `RESULT_DECL' 6892 These nodes represent the value returned by a function. When a 6893 value is assigned to a `RESULT_DECL', that indicates that the 6894 value should be returned, via bitwise copy, by the function. You 6895 can use `DECL_SIZE' and `DECL_ALIGN' on a `RESULT_DECL', just as 6896 with a `VAR_DECL'. 6897 6898 `TYPE_DECL' 6899 These nodes represent `typedef' declarations. The `TREE_TYPE' is 6900 the type declared to have the name given by `DECL_NAME'. In some 6901 cases, there is no associated name. 6902 6903 `VAR_DECL' 6904 These nodes represent variables with namespace or block scope, as 6905 well as static data members. The `DECL_SIZE' and `DECL_ALIGN' are 6906 analogous to `TYPE_SIZE' and `TYPE_ALIGN'. For a declaration, you 6907 should always use the `DECL_SIZE' and `DECL_ALIGN' rather than the 6908 `TYPE_SIZE' and `TYPE_ALIGN' given by the `TREE_TYPE', since 6909 special attributes may have been applied to the variable to give 6910 it a particular size and alignment. You may use the predicates 6911 `DECL_THIS_STATIC' or `DECL_THIS_EXTERN' to test whether the 6912 storage class specifiers `static' or `extern' were used to declare 6913 a variable. 6914 6915 If this variable is initialized (but does not require a 6916 constructor), the `DECL_INITIAL' will be an expression for the 6917 initializer. The initializer should be evaluated, and a bitwise 6918 copy into the variable performed. If the `DECL_INITIAL' is the 6919 `error_mark_node', there is an initializer, but it is given by an 6920 explicit statement later in the code; no bitwise copy is required. 6921 6922 GCC provides an extension that allows either automatic variables, 6923 or global variables, to be placed in particular registers. This 6924 extension is being used for a particular `VAR_DECL' if 6925 `DECL_REGISTER' holds for the `VAR_DECL', and if 6926 `DECL_ASSEMBLER_NAME' is not equal to `DECL_NAME'. In that case, 6927 `DECL_ASSEMBLER_NAME' is the name of the register into which the 6928 variable will be placed. 6929 6930 `PARM_DECL' 6931 Used to represent a parameter to a function. Treat these nodes 6932 similarly to `VAR_DECL' nodes. These nodes only appear in the 6933 `DECL_ARGUMENTS' for a `FUNCTION_DECL'. 6934 6935 The `DECL_ARG_TYPE' for a `PARM_DECL' is the type that will 6936 actually be used when a value is passed to this function. It may 6937 be a wider type than the `TREE_TYPE' of the parameter; for 6938 example, the ordinary type might be `short' while the 6939 `DECL_ARG_TYPE' is `int'. 6940 6941 `FIELD_DECL' 6942 These nodes represent non-static data members. The `DECL_SIZE' and 6943 `DECL_ALIGN' behave as for `VAR_DECL' nodes. The position of the 6944 field within the parent record is specified by a combination of 6945 three attributes. `DECL_FIELD_OFFSET' is the position, counting 6946 in bytes, of the `DECL_OFFSET_ALIGN'-bit sized word containing the 6947 bit of the field closest to the beginning of the structure. 6948 `DECL_FIELD_BIT_OFFSET' is the bit offset of the first bit of the 6949 field within this word; this may be nonzero even for fields that 6950 are not bit-fields, since `DECL_OFFSET_ALIGN' may be greater than 6951 the natural alignment of the field's type. 6952 6953 If `DECL_C_BIT_FIELD' holds, this field is a bit-field. In a 6954 bit-field, `DECL_BIT_FIELD_TYPE' also contains the type that was 6955 originally specified for it, while DECL_TYPE may be a modified 6956 type with lesser precision, according to the size of the bit field. 6957 6958 `NAMESPACE_DECL' 6959 *Note Namespaces::. 6960 6961 `TEMPLATE_DECL' 6962 These nodes are used to represent class, function, and variable 6963 (static data member) templates. The 6964 `DECL_TEMPLATE_SPECIALIZATIONS' are a `TREE_LIST'. The 6965 `TREE_VALUE' of each node in the list is a `TEMPLATE_DECL's or 6966 `FUNCTION_DECL's representing specializations (including 6967 instantiations) of this template. Back ends can safely ignore 6968 `TEMPLATE_DECL's, but should examine `FUNCTION_DECL' nodes on the 6969 specializations list just as they would ordinary `FUNCTION_DECL' 6970 nodes. 6971 6972 For a class template, the `DECL_TEMPLATE_INSTANTIATIONS' list 6973 contains the instantiations. The `TREE_VALUE' of each node is an 6974 instantiation of the class. The `DECL_TEMPLATE_SPECIALIZATIONS' 6975 contains partial specializations of the class. 6976 6977 `USING_DECL' 6978 Back ends can safely ignore these nodes. 6979 6980 6981 6982 File: gccint.info, Node: Internal structure, Prev: Working with declarations, Up: Declarations 6983 6984 9.5.2 Internal structure 6985 ------------------------ 6986 6987 `DECL' nodes are represented internally as a hierarchy of structures. 6988 6989 * Menu: 6990 6991 * Current structure hierarchy:: The current DECL node structure 6992 hierarchy. 6993 * Adding new DECL node types:: How to add a new DECL node to a 6994 frontend. 6995 6996 6997 File: gccint.info, Node: Current structure hierarchy, Next: Adding new DECL node types, Up: Internal structure 6998 6999 9.5.2.1 Current structure hierarchy 7000 ................................... 7001 7002 `struct tree_decl_minimal' 7003 This is the minimal structure to inherit from in order for common 7004 `DECL' macros to work. The fields it contains are a unique ID, 7005 source location, context, and name. 7006 7007 `struct tree_decl_common' 7008 This structure inherits from `struct tree_decl_minimal'. It 7009 contains fields that most `DECL' nodes need, such as a field to 7010 store alignment, machine mode, size, and attributes. 7011 7012 `struct tree_field_decl' 7013 This structure inherits from `struct tree_decl_common'. It is 7014 used to represent `FIELD_DECL'. 7015 7016 `struct tree_label_decl' 7017 This structure inherits from `struct tree_decl_common'. It is 7018 used to represent `LABEL_DECL'. 7019 7020 `struct tree_translation_unit_decl' 7021 This structure inherits from `struct tree_decl_common'. It is 7022 used to represent `TRANSLATION_UNIT_DECL'. 7023 7024 `struct tree_decl_with_rtl' 7025 This structure inherits from `struct tree_decl_common'. It 7026 contains a field to store the low-level RTL associated with a 7027 `DECL' node. 7028 7029 `struct tree_result_decl' 7030 This structure inherits from `struct tree_decl_with_rtl'. It is 7031 used to represent `RESULT_DECL'. 7032 7033 `struct tree_const_decl' 7034 This structure inherits from `struct tree_decl_with_rtl'. It is 7035 used to represent `CONST_DECL'. 7036 7037 `struct tree_parm_decl' 7038 This structure inherits from `struct tree_decl_with_rtl'. It is 7039 used to represent `PARM_DECL'. 7040 7041 `struct tree_decl_with_vis' 7042 This structure inherits from `struct tree_decl_with_rtl'. It 7043 contains fields necessary to store visibility information, as well 7044 as a section name and assembler name. 7045 7046 `struct tree_var_decl' 7047 This structure inherits from `struct tree_decl_with_vis'. It is 7048 used to represent `VAR_DECL'. 7049 7050 `struct tree_function_decl' 7051 This structure inherits from `struct tree_decl_with_vis'. It is 7052 used to represent `FUNCTION_DECL'. 7053 7054 7055 7056 File: gccint.info, Node: Adding new DECL node types, Prev: Current structure hierarchy, Up: Internal structure 7057 7058 9.5.2.2 Adding new DECL node types 7059 .................................. 7060 7061 Adding a new `DECL' tree consists of the following steps 7062 7063 Add a new tree code for the `DECL' node 7064 For language specific `DECL' nodes, there is a `.def' file in each 7065 frontend directory where the tree code should be added. For 7066 `DECL' nodes that are part of the middle-end, the code should be 7067 added to `tree.def'. 7068 7069 Create a new structure type for the `DECL' node 7070 These structures should inherit from one of the existing 7071 structures in the language hierarchy by using that structure as 7072 the first member. 7073 7074 struct tree_foo_decl 7075 { 7076 struct tree_decl_with_vis common; 7077 } 7078 7079 Would create a structure name `tree_foo_decl' that inherits from 7080 `struct tree_decl_with_vis'. 7081 7082 For language specific `DECL' nodes, this new structure type should 7083 go in the appropriate `.h' file. For `DECL' nodes that are part 7084 of the middle-end, the structure type should go in `tree.h'. 7085 7086 Add a member to the tree structure enumerator for the node 7087 For garbage collection and dynamic checking purposes, each `DECL' 7088 node structure type is required to have a unique enumerator value 7089 specified with it. For language specific `DECL' nodes, this new 7090 enumerator value should go in the appropriate `.def' file. For 7091 `DECL' nodes that are part of the middle-end, the enumerator 7092 values are specified in `treestruct.def'. 7093 7094 Update `union tree_node' 7095 In order to make your new structure type usable, it must be added 7096 to `union tree_node'. For language specific `DECL' nodes, a new 7097 entry should be added to the appropriate `.h' file of the form 7098 struct tree_foo_decl GTY ((tag ("TS_VAR_DECL"))) foo_decl; 7099 For `DECL' nodes that are part of the middle-end, the additional 7100 member goes directly into `union tree_node' in `tree.h'. 7101 7102 Update dynamic checking info 7103 In order to be able to check whether accessing a named portion of 7104 `union tree_node' is legal, and whether a certain `DECL' node 7105 contains one of the enumerated `DECL' node structures in the 7106 hierarchy, a simple lookup table is used. This lookup table needs 7107 to be kept up to date with the tree structure hierarchy, or else 7108 checking and containment macros will fail inappropriately. 7109 7110 For language specific `DECL' nodes, their is an `init_ts' function 7111 in an appropriate `.c' file, which initializes the lookup table. 7112 Code setting up the table for new `DECL' nodes should be added 7113 there. For each `DECL' tree code and enumerator value 7114 representing a member of the inheritance hierarchy, the table 7115 should contain 1 if that tree code inherits (directly or 7116 indirectly) from that member. Thus, a `FOO_DECL' node derived 7117 from `struct decl_with_rtl', and enumerator value `TS_FOO_DECL', 7118 would be set up as follows 7119 tree_contains_struct[FOO_DECL][TS_FOO_DECL] = 1; 7120 tree_contains_struct[FOO_DECL][TS_DECL_WRTL] = 1; 7121 tree_contains_struct[FOO_DECL][TS_DECL_COMMON] = 1; 7122 tree_contains_struct[FOO_DECL][TS_DECL_MINIMAL] = 1; 7123 7124 For `DECL' nodes that are part of the middle-end, the setup code 7125 goes into `tree.c'. 7126 7127 Add macros to access any new fields and flags 7128 Each added field or flag should have a macro that is used to access 7129 it, that performs appropriate checking to ensure only the right 7130 type of `DECL' nodes access the field. 7131 7132 These macros generally take the following form 7133 #define FOO_DECL_FIELDNAME(NODE) FOO_DECL_CHECK(NODE)->foo_decl.fieldname 7134 However, if the structure is simply a base class for further 7135 structures, something like the following should be used 7136 #define BASE_STRUCT_CHECK(T) CONTAINS_STRUCT_CHECK(T, TS_BASE_STRUCT) 7137 #define BASE_STRUCT_FIELDNAME(NODE) \ 7138 (BASE_STRUCT_CHECK(NODE)->base_struct.fieldname 7139 7140 7141 7142 File: gccint.info, Node: Functions, Next: Declarations, Prev: Scopes, Up: Trees 7143 7144 9.6 Functions 7145 ============= 7146 7147 A function is represented by a `FUNCTION_DECL' node. A set of 7148 overloaded functions is sometimes represented by a `OVERLOAD' node. 7149 7150 An `OVERLOAD' node is not a declaration, so none of the `DECL_' macros 7151 should be used on an `OVERLOAD'. An `OVERLOAD' node is similar to a 7152 `TREE_LIST'. Use `OVL_CURRENT' to get the function associated with an 7153 `OVERLOAD' node; use `OVL_NEXT' to get the next `OVERLOAD' node in the 7154 list of overloaded functions. The macros `OVL_CURRENT' and `OVL_NEXT' 7155 are actually polymorphic; you can use them to work with `FUNCTION_DECL' 7156 nodes as well as with overloads. In the case of a `FUNCTION_DECL', 7157 `OVL_CURRENT' will always return the function itself, and `OVL_NEXT' 7158 will always be `NULL_TREE'. 7159 7160 To determine the scope of a function, you can use the `DECL_CONTEXT' 7161 macro. This macro will return the class (either a `RECORD_TYPE' or a 7162 `UNION_TYPE') or namespace (a `NAMESPACE_DECL') of which the function 7163 is a member. For a virtual function, this macro returns the class in 7164 which the function was actually defined, not the base class in which 7165 the virtual declaration occurred. 7166 7167 If a friend function is defined in a class scope, the 7168 `DECL_FRIEND_CONTEXT' macro can be used to determine the class in which 7169 it was defined. For example, in 7170 class C { friend void f() {} }; 7171 the `DECL_CONTEXT' for `f' will be the `global_namespace', but the 7172 `DECL_FRIEND_CONTEXT' will be the `RECORD_TYPE' for `C'. 7173 7174 In C, the `DECL_CONTEXT' for a function maybe another function. This 7175 representation indicates that the GNU nested function extension is in 7176 use. For details on the semantics of nested functions, see the GCC 7177 Manual. The nested function can refer to local variables in its 7178 containing function. Such references are not explicitly marked in the 7179 tree structure; back ends must look at the `DECL_CONTEXT' for the 7180 referenced `VAR_DECL'. If the `DECL_CONTEXT' for the referenced 7181 `VAR_DECL' is not the same as the function currently being processed, 7182 and neither `DECL_EXTERNAL' nor `TREE_STATIC' hold, then the reference 7183 is to a local variable in a containing function, and the back end must 7184 take appropriate action. 7185 7186 * Menu: 7187 7188 * Function Basics:: Function names, linkage, and so forth. 7189 * Function Bodies:: The statements that make up a function body. 7190 7191 7192 File: gccint.info, Node: Function Basics, Next: Function Bodies, Up: Functions 7193 7194 9.6.1 Function Basics 7195 --------------------- 7196 7197 The following macros and functions can be used on a `FUNCTION_DECL': 7198 `DECL_MAIN_P' 7199 This predicate holds for a function that is the program entry point 7200 `::code'. 7201 7202 `DECL_NAME' 7203 This macro returns the unqualified name of the function, as an 7204 `IDENTIFIER_NODE'. For an instantiation of a function template, 7205 the `DECL_NAME' is the unqualified name of the template, not 7206 something like `f<int>'. The value of `DECL_NAME' is undefined 7207 when used on a constructor, destructor, overloaded operator, or 7208 type-conversion operator, or any function that is implicitly 7209 generated by the compiler. See below for macros that can be used 7210 to distinguish these cases. 7211 7212 `DECL_ASSEMBLER_NAME' 7213 This macro returns the mangled name of the function, also an 7214 `IDENTIFIER_NODE'. This name does not contain leading underscores 7215 on systems that prefix all identifiers with underscores. The 7216 mangled name is computed in the same way on all platforms; if 7217 special processing is required to deal with the object file format 7218 used on a particular platform, it is the responsibility of the 7219 back end to perform those modifications. (Of course, the back end 7220 should not modify `DECL_ASSEMBLER_NAME' itself.) 7221 7222 Using `DECL_ASSEMBLER_NAME' will cause additional memory to be 7223 allocated (for the mangled name of the entity) so it should be used 7224 only when emitting assembly code. It should not be used within the 7225 optimizers to determine whether or not two declarations are the 7226 same, even though some of the existing optimizers do use it in 7227 that way. These uses will be removed over time. 7228 7229 `DECL_EXTERNAL' 7230 This predicate holds if the function is undefined. 7231 7232 `TREE_PUBLIC' 7233 This predicate holds if the function has external linkage. 7234 7235 `DECL_LOCAL_FUNCTION_P' 7236 This predicate holds if the function was declared at block scope, 7237 even though it has a global scope. 7238 7239 `DECL_ANTICIPATED' 7240 This predicate holds if the function is a built-in function but its 7241 prototype is not yet explicitly declared. 7242 7243 `DECL_EXTERN_C_FUNCTION_P' 7244 This predicate holds if the function is declared as an ``extern 7245 "C"'' function. 7246 7247 `DECL_LINKONCE_P' 7248 This macro holds if multiple copies of this function may be 7249 emitted in various translation units. It is the responsibility of 7250 the linker to merge the various copies. Template instantiations 7251 are the most common example of functions for which 7252 `DECL_LINKONCE_P' holds; G++ instantiates needed templates in all 7253 translation units which require them, and then relies on the 7254 linker to remove duplicate instantiations. 7255 7256 FIXME: This macro is not yet implemented. 7257 7258 `DECL_FUNCTION_MEMBER_P' 7259 This macro holds if the function is a member of a class, rather 7260 than a member of a namespace. 7261 7262 `DECL_STATIC_FUNCTION_P' 7263 This predicate holds if the function a static member function. 7264 7265 `DECL_NONSTATIC_MEMBER_FUNCTION_P' 7266 This macro holds for a non-static member function. 7267 7268 `DECL_CONST_MEMFUNC_P' 7269 This predicate holds for a `const'-member function. 7270 7271 `DECL_VOLATILE_MEMFUNC_P' 7272 This predicate holds for a `volatile'-member function. 7273 7274 `DECL_CONSTRUCTOR_P' 7275 This macro holds if the function is a constructor. 7276 7277 `DECL_NONCONVERTING_P' 7278 This predicate holds if the constructor is a non-converting 7279 constructor. 7280 7281 `DECL_COMPLETE_CONSTRUCTOR_P' 7282 This predicate holds for a function which is a constructor for an 7283 object of a complete type. 7284 7285 `DECL_BASE_CONSTRUCTOR_P' 7286 This predicate holds for a function which is a constructor for a 7287 base class sub-object. 7288 7289 `DECL_COPY_CONSTRUCTOR_P' 7290 This predicate holds for a function which is a copy-constructor. 7291 7292 `DECL_DESTRUCTOR_P' 7293 This macro holds if the function is a destructor. 7294 7295 `DECL_COMPLETE_DESTRUCTOR_P' 7296 This predicate holds if the function is the destructor for an 7297 object a complete type. 7298 7299 `DECL_OVERLOADED_OPERATOR_P' 7300 This macro holds if the function is an overloaded operator. 7301 7302 `DECL_CONV_FN_P' 7303 This macro holds if the function is a type-conversion operator. 7304 7305 `DECL_GLOBAL_CTOR_P' 7306 This predicate holds if the function is a file-scope initialization 7307 function. 7308 7309 `DECL_GLOBAL_DTOR_P' 7310 This predicate holds if the function is a file-scope finalization 7311 function. 7312 7313 `DECL_THUNK_P' 7314 This predicate holds if the function is a thunk. 7315 7316 These functions represent stub code that adjusts the `this' pointer 7317 and then jumps to another function. When the jumped-to function 7318 returns, control is transferred directly to the caller, without 7319 returning to the thunk. The first parameter to the thunk is 7320 always the `this' pointer; the thunk should add `THUNK_DELTA' to 7321 this value. (The `THUNK_DELTA' is an `int', not an `INTEGER_CST'.) 7322 7323 Then, if `THUNK_VCALL_OFFSET' (an `INTEGER_CST') is nonzero the 7324 adjusted `this' pointer must be adjusted again. The complete 7325 calculation is given by the following pseudo-code: 7326 7327 this += THUNK_DELTA 7328 if (THUNK_VCALL_OFFSET) 7329 this += (*((ptrdiff_t **) this))[THUNK_VCALL_OFFSET] 7330 7331 Finally, the thunk should jump to the location given by 7332 `DECL_INITIAL'; this will always be an expression for the address 7333 of a function. 7334 7335 `DECL_NON_THUNK_FUNCTION_P' 7336 This predicate holds if the function is _not_ a thunk function. 7337 7338 `GLOBAL_INIT_PRIORITY' 7339 If either `DECL_GLOBAL_CTOR_P' or `DECL_GLOBAL_DTOR_P' holds, then 7340 this gives the initialization priority for the function. The 7341 linker will arrange that all functions for which 7342 `DECL_GLOBAL_CTOR_P' holds are run in increasing order of priority 7343 before `main' is called. When the program exits, all functions for 7344 which `DECL_GLOBAL_DTOR_P' holds are run in the reverse order. 7345 7346 `DECL_ARTIFICIAL' 7347 This macro holds if the function was implicitly generated by the 7348 compiler, rather than explicitly declared. In addition to 7349 implicitly generated class member functions, this macro holds for 7350 the special functions created to implement static initialization 7351 and destruction, to compute run-time type information, and so 7352 forth. 7353 7354 `DECL_ARGUMENTS' 7355 This macro returns the `PARM_DECL' for the first argument to the 7356 function. Subsequent `PARM_DECL' nodes can be obtained by 7357 following the `TREE_CHAIN' links. 7358 7359 `DECL_RESULT' 7360 This macro returns the `RESULT_DECL' for the function. 7361 7362 `TREE_TYPE' 7363 This macro returns the `FUNCTION_TYPE' or `METHOD_TYPE' for the 7364 function. 7365 7366 `TYPE_RAISES_EXCEPTIONS' 7367 This macro returns the list of exceptions that a (member-)function 7368 can raise. The returned list, if non `NULL', is comprised of nodes 7369 whose `TREE_VALUE' represents a type. 7370 7371 `TYPE_NOTHROW_P' 7372 This predicate holds when the exception-specification of its 7373 arguments is of the form ``()''. 7374 7375 `DECL_ARRAY_DELETE_OPERATOR_P' 7376 This predicate holds if the function an overloaded `operator 7377 delete[]'. 7378 7379 `DECL_FUNCTION_SPECIFIC_TARGET' 7380 This macro returns a tree node that holds the target options that 7381 are to be used to compile this particular function or `NULL_TREE' 7382 if the function is to be compiled with the target options 7383 specified on the command line. 7384 7385 `DECL_FUNCTION_SPECIFIC_OPTIMIZATION' 7386 This macro returns a tree node that holds the optimization options 7387 that are to be used to compile this particular function or 7388 `NULL_TREE' if the function is to be compiled with the 7389 optimization options specified on the command line. 7390 7391 7392 File: gccint.info, Node: Function Bodies, Prev: Function Basics, Up: Functions 7393 7394 9.6.2 Function Bodies 7395 --------------------- 7396 7397 A function that has a definition in the current translation unit will 7398 have a non-`NULL' `DECL_INITIAL'. However, back ends should not make 7399 use of the particular value given by `DECL_INITIAL'. 7400 7401 The `DECL_SAVED_TREE' macro will give the complete body of the 7402 function. 7403 7404 9.6.2.1 Statements 7405 .................. 7406 7407 There are tree nodes corresponding to all of the source-level statement 7408 constructs, used within the C and C++ frontends. These are enumerated 7409 here, together with a list of the various macros that can be used to 7410 obtain information about them. There are a few macros that can be used 7411 with all statements: 7412 7413 `STMT_IS_FULL_EXPR_P' 7414 In C++, statements normally constitute "full expressions"; 7415 temporaries created during a statement are destroyed when the 7416 statement is complete. However, G++ sometimes represents 7417 expressions by statements; these statements will not have 7418 `STMT_IS_FULL_EXPR_P' set. Temporaries created during such 7419 statements should be destroyed when the innermost enclosing 7420 statement with `STMT_IS_FULL_EXPR_P' set is exited. 7421 7422 7423 Here is the list of the various statement nodes, and the macros used to 7424 access them. This documentation describes the use of these nodes in 7425 non-template functions (including instantiations of template functions). 7426 In template functions, the same nodes are used, but sometimes in 7427 slightly different ways. 7428 7429 Many of the statements have substatements. For example, a `while' 7430 loop will have a body, which is itself a statement. If the substatement 7431 is `NULL_TREE', it is considered equivalent to a statement consisting 7432 of a single `;', i.e., an expression statement in which the expression 7433 has been omitted. A substatement may in fact be a list of statements, 7434 connected via their `TREE_CHAIN's. So, you should always process the 7435 statement tree by looping over substatements, like this: 7436 void process_stmt (stmt) 7437 tree stmt; 7438 { 7439 while (stmt) 7440 { 7441 switch (TREE_CODE (stmt)) 7442 { 7443 case IF_STMT: 7444 process_stmt (THEN_CLAUSE (stmt)); 7445 /* More processing here. */ 7446 break; 7447 7448 ... 7449 } 7450 7451 stmt = TREE_CHAIN (stmt); 7452 } 7453 } 7454 In other words, while the `then' clause of an `if' statement in C++ 7455 can be only one statement (although that one statement may be a 7456 compound statement), the intermediate representation will sometimes use 7457 several statements chained together. 7458 7459 `ASM_EXPR' 7460 Used to represent an inline assembly statement. For an inline 7461 assembly statement like: 7462 asm ("mov x, y"); 7463 The `ASM_STRING' macro will return a `STRING_CST' node for `"mov 7464 x, y"'. If the original statement made use of the 7465 extended-assembly syntax, then `ASM_OUTPUTS', `ASM_INPUTS', and 7466 `ASM_CLOBBERS' will be the outputs, inputs, and clobbers for the 7467 statement, represented as `STRING_CST' nodes. The 7468 extended-assembly syntax looks like: 7469 asm ("fsinx %1,%0" : "=f" (result) : "f" (angle)); 7470 The first string is the `ASM_STRING', containing the instruction 7471 template. The next two strings are the output and inputs, 7472 respectively; this statement has no clobbers. As this example 7473 indicates, "plain" assembly statements are merely a special case 7474 of extended assembly statements; they have no cv-qualifiers, 7475 outputs, inputs, or clobbers. All of the strings will be 7476 `NUL'-terminated, and will contain no embedded `NUL'-characters. 7477 7478 If the assembly statement is declared `volatile', or if the 7479 statement was not an extended assembly statement, and is therefore 7480 implicitly volatile, then the predicate `ASM_VOLATILE_P' will hold 7481 of the `ASM_EXPR'. 7482 7483 `BREAK_STMT' 7484 Used to represent a `break' statement. There are no additional 7485 fields. 7486 7487 `CASE_LABEL_EXPR' 7488 Use to represent a `case' label, range of `case' labels, or a 7489 `default' label. If `CASE_LOW' is `NULL_TREE', then this is a 7490 `default' label. Otherwise, if `CASE_HIGH' is `NULL_TREE', then 7491 this is an ordinary `case' label. In this case, `CASE_LOW' is an 7492 expression giving the value of the label. Both `CASE_LOW' and 7493 `CASE_HIGH' are `INTEGER_CST' nodes. These values will have the 7494 same type as the condition expression in the switch statement. 7495 7496 Otherwise, if both `CASE_LOW' and `CASE_HIGH' are defined, the 7497 statement is a range of case labels. Such statements originate 7498 with the extension that allows users to write things of the form: 7499 case 2 ... 5: 7500 The first value will be `CASE_LOW', while the second will be 7501 `CASE_HIGH'. 7502 7503 `CLEANUP_STMT' 7504 Used to represent an action that should take place upon exit from 7505 the enclosing scope. Typically, these actions are calls to 7506 destructors for local objects, but back ends cannot rely on this 7507 fact. If these nodes are in fact representing such destructors, 7508 `CLEANUP_DECL' will be the `VAR_DECL' destroyed. Otherwise, 7509 `CLEANUP_DECL' will be `NULL_TREE'. In any case, the 7510 `CLEANUP_EXPR' is the expression to execute. The cleanups 7511 executed on exit from a scope should be run in the reverse order 7512 of the order in which the associated `CLEANUP_STMT's were 7513 encountered. 7514 7515 `CONTINUE_STMT' 7516 Used to represent a `continue' statement. There are no additional 7517 fields. 7518 7519 `CTOR_STMT' 7520 Used to mark the beginning (if `CTOR_BEGIN_P' holds) or end (if 7521 `CTOR_END_P' holds of the main body of a constructor. See also 7522 `SUBOBJECT' for more information on how to use these nodes. 7523 7524 `DECL_STMT' 7525 Used to represent a local declaration. The `DECL_STMT_DECL' macro 7526 can be used to obtain the entity declared. This declaration may 7527 be a `LABEL_DECL', indicating that the label declared is a local 7528 label. (As an extension, GCC allows the declaration of labels 7529 with scope.) In C, this declaration may be a `FUNCTION_DECL', 7530 indicating the use of the GCC nested function extension. For more 7531 information, *note Functions::. 7532 7533 `DO_STMT' 7534 Used to represent a `do' loop. The body of the loop is given by 7535 `DO_BODY' while the termination condition for the loop is given by 7536 `DO_COND'. The condition for a `do'-statement is always an 7537 expression. 7538 7539 `EMPTY_CLASS_EXPR' 7540 Used to represent a temporary object of a class with no data whose 7541 address is never taken. (All such objects are interchangeable.) 7542 The `TREE_TYPE' represents the type of the object. 7543 7544 `EXPR_STMT' 7545 Used to represent an expression statement. Use `EXPR_STMT_EXPR' to 7546 obtain the expression. 7547 7548 `FOR_STMT' 7549 Used to represent a `for' statement. The `FOR_INIT_STMT' is the 7550 initialization statement for the loop. The `FOR_COND' is the 7551 termination condition. The `FOR_EXPR' is the expression executed 7552 right before the `FOR_COND' on each loop iteration; often, this 7553 expression increments a counter. The body of the loop is given by 7554 `FOR_BODY'. Note that `FOR_INIT_STMT' and `FOR_BODY' return 7555 statements, while `FOR_COND' and `FOR_EXPR' return expressions. 7556 7557 `GOTO_EXPR' 7558 Used to represent a `goto' statement. The `GOTO_DESTINATION' will 7559 usually be a `LABEL_DECL'. However, if the "computed goto" 7560 extension has been used, the `GOTO_DESTINATION' will be an 7561 arbitrary expression indicating the destination. This expression 7562 will always have pointer type. 7563 7564 `HANDLER' 7565 Used to represent a C++ `catch' block. The `HANDLER_TYPE' is the 7566 type of exception that will be caught by this handler; it is equal 7567 (by pointer equality) to `NULL' if this handler is for all types. 7568 `HANDLER_PARMS' is the `DECL_STMT' for the catch parameter, and 7569 `HANDLER_BODY' is the code for the block itself. 7570 7571 `IF_STMT' 7572 Used to represent an `if' statement. The `IF_COND' is the 7573 expression. 7574 7575 If the condition is a `TREE_LIST', then the `TREE_PURPOSE' is a 7576 statement (usually a `DECL_STMT'). Each time the condition is 7577 evaluated, the statement should be executed. Then, the 7578 `TREE_VALUE' should be used as the conditional expression itself. 7579 This representation is used to handle C++ code like this: 7580 7581 if (int i = 7) ... 7582 7583 where there is a new local variable (or variables) declared within 7584 the condition. 7585 7586 The `THEN_CLAUSE' represents the statement given by the `then' 7587 condition, while the `ELSE_CLAUSE' represents the statement given 7588 by the `else' condition. 7589 7590 `LABEL_EXPR' 7591 Used to represent a label. The `LABEL_DECL' declared by this 7592 statement can be obtained with the `LABEL_EXPR_LABEL' macro. The 7593 `IDENTIFIER_NODE' giving the name of the label can be obtained from 7594 the `LABEL_DECL' with `DECL_NAME'. 7595 7596 `RETURN_STMT' 7597 Used to represent a `return' statement. The `RETURN_EXPR' is the 7598 expression returned; it will be `NULL_TREE' if the statement was 7599 just 7600 return; 7601 7602 `SUBOBJECT' 7603 In a constructor, these nodes are used to mark the point at which a 7604 subobject of `this' is fully constructed. If, after this point, an 7605 exception is thrown before a `CTOR_STMT' with `CTOR_END_P' set is 7606 encountered, the `SUBOBJECT_CLEANUP' must be executed. The 7607 cleanups must be executed in the reverse order in which they 7608 appear. 7609 7610 `SWITCH_STMT' 7611 Used to represent a `switch' statement. The `SWITCH_STMT_COND' is 7612 the expression on which the switch is occurring. See the 7613 documentation for an `IF_STMT' for more information on the 7614 representation used for the condition. The `SWITCH_STMT_BODY' is 7615 the body of the switch statement. The `SWITCH_STMT_TYPE' is the 7616 original type of switch expression as given in the source, before 7617 any compiler conversions. 7618 7619 `TRY_BLOCK' 7620 Used to represent a `try' block. The body of the try block is 7621 given by `TRY_STMTS'. Each of the catch blocks is a `HANDLER' 7622 node. The first handler is given by `TRY_HANDLERS'. Subsequent 7623 handlers are obtained by following the `TREE_CHAIN' link from one 7624 handler to the next. The body of the handler is given by 7625 `HANDLER_BODY'. 7626 7627 If `CLEANUP_P' holds of the `TRY_BLOCK', then the `TRY_HANDLERS' 7628 will not be a `HANDLER' node. Instead, it will be an expression 7629 that should be executed if an exception is thrown in the try 7630 block. It must rethrow the exception after executing that code. 7631 And, if an exception is thrown while the expression is executing, 7632 `terminate' must be called. 7633 7634 `USING_STMT' 7635 Used to represent a `using' directive. The namespace is given by 7636 `USING_STMT_NAMESPACE', which will be a NAMESPACE_DECL. This node 7637 is needed inside template functions, to implement using directives 7638 during instantiation. 7639 7640 `WHILE_STMT' 7641 Used to represent a `while' loop. The `WHILE_COND' is the 7642 termination condition for the loop. See the documentation for an 7643 `IF_STMT' for more information on the representation used for the 7644 condition. 7645 7646 The `WHILE_BODY' is the body of the loop. 7647 7648 7649 7650 File: gccint.info, Node: Attributes, Next: Expression trees, Prev: Declarations, Up: Trees 7651 7652 9.7 Attributes in trees 7653 ======================= 7654 7655 Attributes, as specified using the `__attribute__' keyword, are 7656 represented internally as a `TREE_LIST'. The `TREE_PURPOSE' is the 7657 name of the attribute, as an `IDENTIFIER_NODE'. The `TREE_VALUE' is a 7658 `TREE_LIST' of the arguments of the attribute, if any, or `NULL_TREE' 7659 if there are no arguments; the arguments are stored as the `TREE_VALUE' 7660 of successive entries in the list, and may be identifiers or 7661 expressions. The `TREE_CHAIN' of the attribute is the next attribute 7662 in a list of attributes applying to the same declaration or type, or 7663 `NULL_TREE' if there are no further attributes in the list. 7664 7665 Attributes may be attached to declarations and to types; these 7666 attributes may be accessed with the following macros. All attributes 7667 are stored in this way, and many also cause other changes to the 7668 declaration or type or to other internal compiler data structures. 7669 7670 -- Tree Macro: tree DECL_ATTRIBUTES (tree DECL) 7671 This macro returns the attributes on the declaration DECL. 7672 7673 -- Tree Macro: tree TYPE_ATTRIBUTES (tree TYPE) 7674 This macro returns the attributes on the type TYPE. 7675 7676 7677 File: gccint.info, Node: Expression trees, Prev: Attributes, Up: Trees 7678 7679 9.8 Expressions 7680 =============== 7681 7682 The internal representation for expressions is for the most part quite 7683 straightforward. However, there are a few facts that one must bear in 7684 mind. In particular, the expression "tree" is actually a directed 7685 acyclic graph. (For example there may be many references to the integer 7686 constant zero throughout the source program; many of these will be 7687 represented by the same expression node.) You should not rely on 7688 certain kinds of node being shared, nor should you rely on certain 7689 kinds of nodes being unshared. 7690 7691 The following macros can be used with all expression nodes: 7692 7693 `TREE_TYPE' 7694 Returns the type of the expression. This value may not be 7695 precisely the same type that would be given the expression in the 7696 original program. 7697 7698 In what follows, some nodes that one might expect to always have type 7699 `bool' are documented to have either integral or boolean type. At some 7700 point in the future, the C front end may also make use of this same 7701 intermediate representation, and at this point these nodes will 7702 certainly have integral type. The previous sentence is not meant to 7703 imply that the C++ front end does not or will not give these nodes 7704 integral type. 7705 7706 Below, we list the various kinds of expression nodes. Except where 7707 noted otherwise, the operands to an expression are accessed using the 7708 `TREE_OPERAND' macro. For example, to access the first operand to a 7709 binary plus expression `expr', use: 7710 7711 TREE_OPERAND (expr, 0) 7712 As this example indicates, the operands are zero-indexed. 7713 7714 All the expressions starting with `OMP_' represent directives and 7715 clauses used by the OpenMP API `http://www.openmp.org/'. 7716 7717 The table below begins with constants, moves on to unary expressions, 7718 then proceeds to binary expressions, and concludes with various other 7719 kinds of expressions: 7720 7721 `INTEGER_CST' 7722 These nodes represent integer constants. Note that the type of 7723 these constants is obtained with `TREE_TYPE'; they are not always 7724 of type `int'. In particular, `char' constants are represented 7725 with `INTEGER_CST' nodes. The value of the integer constant `e' is 7726 given by 7727 ((TREE_INT_CST_HIGH (e) << HOST_BITS_PER_WIDE_INT) 7728 + TREE_INST_CST_LOW (e)) 7729 HOST_BITS_PER_WIDE_INT is at least thirty-two on all platforms. 7730 Both `TREE_INT_CST_HIGH' and `TREE_INT_CST_LOW' return a 7731 `HOST_WIDE_INT'. The value of an `INTEGER_CST' is interpreted as 7732 a signed or unsigned quantity depending on the type of the 7733 constant. In general, the expression given above will overflow, 7734 so it should not be used to calculate the value of the constant. 7735 7736 The variable `integer_zero_node' is an integer constant with value 7737 zero. Similarly, `integer_one_node' is an integer constant with 7738 value one. The `size_zero_node' and `size_one_node' variables are 7739 analogous, but have type `size_t' rather than `int'. 7740 7741 The function `tree_int_cst_lt' is a predicate which holds if its 7742 first argument is less than its second. Both constants are 7743 assumed to have the same signedness (i.e., either both should be 7744 signed or both should be unsigned.) The full width of the 7745 constant is used when doing the comparison; the usual rules about 7746 promotions and conversions are ignored. Similarly, 7747 `tree_int_cst_equal' holds if the two constants are equal. The 7748 `tree_int_cst_sgn' function returns the sign of a constant. The 7749 value is `1', `0', or `-1' according on whether the constant is 7750 greater than, equal to, or less than zero. Again, the signedness 7751 of the constant's type is taken into account; an unsigned constant 7752 is never less than zero, no matter what its bit-pattern. 7753 7754 `REAL_CST' 7755 FIXME: Talk about how to obtain representations of this constant, 7756 do comparisons, and so forth. 7757 7758 `FIXED_CST' 7759 These nodes represent fixed-point constants. The type of these 7760 constants is obtained with `TREE_TYPE'. `TREE_FIXED_CST_PTR' 7761 points to to struct fixed_value; `TREE_FIXED_CST' returns the 7762 structure itself. Struct fixed_value contains `data' with the 7763 size of two HOST_BITS_PER_WIDE_INT and `mode' as the associated 7764 fixed-point machine mode for `data'. 7765 7766 `COMPLEX_CST' 7767 These nodes are used to represent complex number constants, that 7768 is a `__complex__' whose parts are constant nodes. The 7769 `TREE_REALPART' and `TREE_IMAGPART' return the real and the 7770 imaginary parts respectively. 7771 7772 `VECTOR_CST' 7773 These nodes are used to represent vector constants, whose parts are 7774 constant nodes. Each individual constant node is either an 7775 integer or a double constant node. The first operand is a 7776 `TREE_LIST' of the constant nodes and is accessed through 7777 `TREE_VECTOR_CST_ELTS'. 7778 7779 `STRING_CST' 7780 These nodes represent string-constants. The `TREE_STRING_LENGTH' 7781 returns the length of the string, as an `int'. The 7782 `TREE_STRING_POINTER' is a `char*' containing the string itself. 7783 The string may not be `NUL'-terminated, and it may contain 7784 embedded `NUL' characters. Therefore, the `TREE_STRING_LENGTH' 7785 includes the trailing `NUL' if it is present. 7786 7787 For wide string constants, the `TREE_STRING_LENGTH' is the number 7788 of bytes in the string, and the `TREE_STRING_POINTER' points to an 7789 array of the bytes of the string, as represented on the target 7790 system (that is, as integers in the target endianness). Wide and 7791 non-wide string constants are distinguished only by the `TREE_TYPE' 7792 of the `STRING_CST'. 7793 7794 FIXME: The formats of string constants are not well-defined when 7795 the target system bytes are not the same width as host system 7796 bytes. 7797 7798 `PTRMEM_CST' 7799 These nodes are used to represent pointer-to-member constants. The 7800 `PTRMEM_CST_CLASS' is the class type (either a `RECORD_TYPE' or 7801 `UNION_TYPE' within which the pointer points), and the 7802 `PTRMEM_CST_MEMBER' is the declaration for the pointed to object. 7803 Note that the `DECL_CONTEXT' for the `PTRMEM_CST_MEMBER' is in 7804 general different from the `PTRMEM_CST_CLASS'. For example, given: 7805 struct B { int i; }; 7806 struct D : public B {}; 7807 int D::*dp = &D::i; 7808 The `PTRMEM_CST_CLASS' for `&D::i' is `D', even though the 7809 `DECL_CONTEXT' for the `PTRMEM_CST_MEMBER' is `B', since `B::i' is 7810 a member of `B', not `D'. 7811 7812 `VAR_DECL' 7813 These nodes represent variables, including static data members. 7814 For more information, *note Declarations::. 7815 7816 `NEGATE_EXPR' 7817 These nodes represent unary negation of the single operand, for 7818 both integer and floating-point types. The type of negation can be 7819 determined by looking at the type of the expression. 7820 7821 The behavior of this operation on signed arithmetic overflow is 7822 controlled by the `flag_wrapv' and `flag_trapv' variables. 7823 7824 `ABS_EXPR' 7825 These nodes represent the absolute value of the single operand, for 7826 both integer and floating-point types. This is typically used to 7827 implement the `abs', `labs' and `llabs' builtins for integer 7828 types, and the `fabs', `fabsf' and `fabsl' builtins for floating 7829 point types. The type of abs operation can be determined by 7830 looking at the type of the expression. 7831 7832 This node is not used for complex types. To represent the modulus 7833 or complex abs of a complex value, use the `BUILT_IN_CABS', 7834 `BUILT_IN_CABSF' or `BUILT_IN_CABSL' builtins, as used to 7835 implement the C99 `cabs', `cabsf' and `cabsl' built-in functions. 7836 7837 `BIT_NOT_EXPR' 7838 These nodes represent bitwise complement, and will always have 7839 integral type. The only operand is the value to be complemented. 7840 7841 `TRUTH_NOT_EXPR' 7842 These nodes represent logical negation, and will always have 7843 integral (or boolean) type. The operand is the value being 7844 negated. The type of the operand and that of the result are 7845 always of `BOOLEAN_TYPE' or `INTEGER_TYPE'. 7846 7847 `PREDECREMENT_EXPR' 7848 `PREINCREMENT_EXPR' 7849 `POSTDECREMENT_EXPR' 7850 `POSTINCREMENT_EXPR' 7851 These nodes represent increment and decrement expressions. The 7852 value of the single operand is computed, and the operand 7853 incremented or decremented. In the case of `PREDECREMENT_EXPR' and 7854 `PREINCREMENT_EXPR', the value of the expression is the value 7855 resulting after the increment or decrement; in the case of 7856 `POSTDECREMENT_EXPR' and `POSTINCREMENT_EXPR' is the value before 7857 the increment or decrement occurs. The type of the operand, like 7858 that of the result, will be either integral, boolean, or 7859 floating-point. 7860 7861 `ADDR_EXPR' 7862 These nodes are used to represent the address of an object. (These 7863 expressions will always have pointer or reference type.) The 7864 operand may be another expression, or it may be a declaration. 7865 7866 As an extension, GCC allows users to take the address of a label. 7867 In this case, the operand of the `ADDR_EXPR' will be a 7868 `LABEL_DECL'. The type of such an expression is `void*'. 7869 7870 If the object addressed is not an lvalue, a temporary is created, 7871 and the address of the temporary is used. 7872 7873 `INDIRECT_REF' 7874 These nodes are used to represent the object pointed to by a 7875 pointer. The operand is the pointer being dereferenced; it will 7876 always have pointer or reference type. 7877 7878 `FIX_TRUNC_EXPR' 7879 These nodes represent conversion of a floating-point value to an 7880 integer. The single operand will have a floating-point type, while 7881 the complete expression will have an integral (or boolean) type. 7882 The operand is rounded towards zero. 7883 7884 `FLOAT_EXPR' 7885 These nodes represent conversion of an integral (or boolean) value 7886 to a floating-point value. The single operand will have integral 7887 type, while the complete expression will have a floating-point 7888 type. 7889 7890 FIXME: How is the operand supposed to be rounded? Is this 7891 dependent on `-mieee'? 7892 7893 `COMPLEX_EXPR' 7894 These nodes are used to represent complex numbers constructed from 7895 two expressions of the same (integer or real) type. The first 7896 operand is the real part and the second operand is the imaginary 7897 part. 7898 7899 `CONJ_EXPR' 7900 These nodes represent the conjugate of their operand. 7901 7902 `REALPART_EXPR' 7903 `IMAGPART_EXPR' 7904 These nodes represent respectively the real and the imaginary parts 7905 of complex numbers (their sole argument). 7906 7907 `NON_LVALUE_EXPR' 7908 These nodes indicate that their one and only operand is not an 7909 lvalue. A back end can treat these identically to the single 7910 operand. 7911 7912 `NOP_EXPR' 7913 These nodes are used to represent conversions that do not require 7914 any code-generation. For example, conversion of a `char*' to an 7915 `int*' does not require any code be generated; such a conversion is 7916 represented by a `NOP_EXPR'. The single operand is the expression 7917 to be converted. The conversion from a pointer to a reference is 7918 also represented with a `NOP_EXPR'. 7919 7920 `CONVERT_EXPR' 7921 These nodes are similar to `NOP_EXPR's, but are used in those 7922 situations where code may need to be generated. For example, if an 7923 `int*' is converted to an `int' code may need to be generated on 7924 some platforms. These nodes are never used for C++-specific 7925 conversions, like conversions between pointers to different 7926 classes in an inheritance hierarchy. Any adjustments that need to 7927 be made in such cases are always indicated explicitly. Similarly, 7928 a user-defined conversion is never represented by a 7929 `CONVERT_EXPR'; instead, the function calls are made explicit. 7930 7931 `FIXED_CONVERT_EXPR' 7932 These nodes are used to represent conversions that involve 7933 fixed-point values. For example, from a fixed-point value to 7934 another fixed-point value, from an integer to a fixed-point value, 7935 from a fixed-point value to an integer, from a floating-point 7936 value to a fixed-point value, or from a fixed-point value to a 7937 floating-point value. 7938 7939 `THROW_EXPR' 7940 These nodes represent `throw' expressions. The single operand is 7941 an expression for the code that should be executed to throw the 7942 exception. However, there is one implicit action not represented 7943 in that expression; namely the call to `__throw'. This function 7944 takes no arguments. If `setjmp'/`longjmp' exceptions are used, the 7945 function `__sjthrow' is called instead. The normal GCC back end 7946 uses the function `emit_throw' to generate this code; you can 7947 examine this function to see what needs to be done. 7948 7949 `LSHIFT_EXPR' 7950 `RSHIFT_EXPR' 7951 These nodes represent left and right shifts, respectively. The 7952 first operand is the value to shift; it will always be of integral 7953 type. The second operand is an expression for the number of bits 7954 by which to shift. Right shift should be treated as arithmetic, 7955 i.e., the high-order bits should be zero-filled when the 7956 expression has unsigned type and filled with the sign bit when the 7957 expression has signed type. Note that the result is undefined if 7958 the second operand is larger than or equal to the first operand's 7959 type size. 7960 7961 `BIT_IOR_EXPR' 7962 `BIT_XOR_EXPR' 7963 `BIT_AND_EXPR' 7964 These nodes represent bitwise inclusive or, bitwise exclusive or, 7965 and bitwise and, respectively. Both operands will always have 7966 integral type. 7967 7968 `TRUTH_ANDIF_EXPR' 7969 `TRUTH_ORIF_EXPR' 7970 These nodes represent logical "and" and logical "or", respectively. 7971 These operators are not strict; i.e., the second operand is 7972 evaluated only if the value of the expression is not determined by 7973 evaluation of the first operand. The type of the operands and 7974 that of the result are always of `BOOLEAN_TYPE' or `INTEGER_TYPE'. 7975 7976 `TRUTH_AND_EXPR' 7977 `TRUTH_OR_EXPR' 7978 `TRUTH_XOR_EXPR' 7979 These nodes represent logical and, logical or, and logical 7980 exclusive or. They are strict; both arguments are always 7981 evaluated. There are no corresponding operators in C or C++, but 7982 the front end will sometimes generate these expressions anyhow, if 7983 it can tell that strictness does not matter. The type of the 7984 operands and that of the result are always of `BOOLEAN_TYPE' or 7985 `INTEGER_TYPE'. 7986 7987 `POINTER_PLUS_EXPR' 7988 This node represents pointer arithmetic. The first operand is 7989 always a pointer/reference type. The second operand is always an 7990 unsigned integer type compatible with sizetype. This is the only 7991 binary arithmetic operand that can operate on pointer types. 7992 7993 `PLUS_EXPR' 7994 `MINUS_EXPR' 7995 `MULT_EXPR' 7996 These nodes represent various binary arithmetic operations. 7997 Respectively, these operations are addition, subtraction (of the 7998 second operand from the first) and multiplication. Their operands 7999 may have either integral or floating type, but there will never be 8000 case in which one operand is of floating type and the other is of 8001 integral type. 8002 8003 The behavior of these operations on signed arithmetic overflow is 8004 controlled by the `flag_wrapv' and `flag_trapv' variables. 8005 8006 `RDIV_EXPR' 8007 This node represents a floating point division operation. 8008 8009 `TRUNC_DIV_EXPR' 8010 `FLOOR_DIV_EXPR' 8011 `CEIL_DIV_EXPR' 8012 `ROUND_DIV_EXPR' 8013 These nodes represent integer division operations that return an 8014 integer result. `TRUNC_DIV_EXPR' rounds towards zero, 8015 `FLOOR_DIV_EXPR' rounds towards negative infinity, `CEIL_DIV_EXPR' 8016 rounds towards positive infinity and `ROUND_DIV_EXPR' rounds to 8017 the closest integer. Integer division in C and C++ is truncating, 8018 i.e. `TRUNC_DIV_EXPR'. 8019 8020 The behavior of these operations on signed arithmetic overflow, 8021 when dividing the minimum signed integer by minus one, is 8022 controlled by the `flag_wrapv' and `flag_trapv' variables. 8023 8024 `TRUNC_MOD_EXPR' 8025 `FLOOR_MOD_EXPR' 8026 `CEIL_MOD_EXPR' 8027 `ROUND_MOD_EXPR' 8028 These nodes represent the integer remainder or modulus operation. 8029 The integer modulus of two operands `a' and `b' is defined as `a - 8030 (a/b)*b' where the division calculated using the corresponding 8031 division operator. Hence for `TRUNC_MOD_EXPR' this definition 8032 assumes division using truncation towards zero, i.e. 8033 `TRUNC_DIV_EXPR'. Integer remainder in C and C++ uses truncating 8034 division, i.e. `TRUNC_MOD_EXPR'. 8035 8036 `EXACT_DIV_EXPR' 8037 The `EXACT_DIV_EXPR' code is used to represent integer divisions 8038 where the numerator is known to be an exact multiple of the 8039 denominator. This allows the backend to choose between the faster 8040 of `TRUNC_DIV_EXPR', `CEIL_DIV_EXPR' and `FLOOR_DIV_EXPR' for the 8041 current target. 8042 8043 `ARRAY_REF' 8044 These nodes represent array accesses. The first operand is the 8045 array; the second is the index. To calculate the address of the 8046 memory accessed, you must scale the index by the size of the type 8047 of the array elements. The type of these expressions must be the 8048 type of a component of the array. The third and fourth operands 8049 are used after gimplification to represent the lower bound and 8050 component size but should not be used directly; call 8051 `array_ref_low_bound' and `array_ref_element_size' instead. 8052 8053 `ARRAY_RANGE_REF' 8054 These nodes represent access to a range (or "slice") of an array. 8055 The operands are the same as that for `ARRAY_REF' and have the same 8056 meanings. The type of these expressions must be an array whose 8057 component type is the same as that of the first operand. The 8058 range of that array type determines the amount of data these 8059 expressions access. 8060 8061 `TARGET_MEM_REF' 8062 These nodes represent memory accesses whose address directly map to 8063 an addressing mode of the target architecture. The first argument 8064 is `TMR_SYMBOL' and must be a `VAR_DECL' of an object with a fixed 8065 address. The second argument is `TMR_BASE' and the third one is 8066 `TMR_INDEX'. The fourth argument is `TMR_STEP' and must be an 8067 `INTEGER_CST'. The fifth argument is `TMR_OFFSET' and must be an 8068 `INTEGER_CST'. Any of the arguments may be NULL if the 8069 appropriate component does not appear in the address. Address of 8070 the `TARGET_MEM_REF' is determined in the following way. 8071 8072 &TMR_SYMBOL + TMR_BASE + TMR_INDEX * TMR_STEP + TMR_OFFSET 8073 8074 The sixth argument is the reference to the original memory access, 8075 which is preserved for the purposes of the RTL alias analysis. 8076 The seventh argument is a tag representing the results of tree 8077 level alias analysis. 8078 8079 `LT_EXPR' 8080 `LE_EXPR' 8081 `GT_EXPR' 8082 `GE_EXPR' 8083 `EQ_EXPR' 8084 `NE_EXPR' 8085 These nodes represent the less than, less than or equal to, greater 8086 than, greater than or equal to, equal, and not equal comparison 8087 operators. The first and second operand with either be both of 8088 integral type or both of floating type. The result type of these 8089 expressions will always be of integral or boolean type. These 8090 operations return the result type's zero value for false, and the 8091 result type's one value for true. 8092 8093 For floating point comparisons, if we honor IEEE NaNs and either 8094 operand is NaN, then `NE_EXPR' always returns true and the 8095 remaining operators always return false. On some targets, 8096 comparisons against an IEEE NaN, other than equality and 8097 inequality, may generate a floating point exception. 8098 8099 `ORDERED_EXPR' 8100 `UNORDERED_EXPR' 8101 These nodes represent non-trapping ordered and unordered comparison 8102 operators. These operations take two floating point operands and 8103 determine whether they are ordered or unordered relative to each 8104 other. If either operand is an IEEE NaN, their comparison is 8105 defined to be unordered, otherwise the comparison is defined to be 8106 ordered. The result type of these expressions will always be of 8107 integral or boolean type. These operations return the result 8108 type's zero value for false, and the result type's one value for 8109 true. 8110 8111 `UNLT_EXPR' 8112 `UNLE_EXPR' 8113 `UNGT_EXPR' 8114 `UNGE_EXPR' 8115 `UNEQ_EXPR' 8116 `LTGT_EXPR' 8117 These nodes represent the unordered comparison operators. These 8118 operations take two floating point operands and determine whether 8119 the operands are unordered or are less than, less than or equal to, 8120 greater than, greater than or equal to, or equal respectively. For 8121 example, `UNLT_EXPR' returns true if either operand is an IEEE NaN 8122 or the first operand is less than the second. With the possible 8123 exception of `LTGT_EXPR', all of these operations are guaranteed 8124 not to generate a floating point exception. The result type of 8125 these expressions will always be of integral or boolean type. 8126 These operations return the result type's zero value for false, 8127 and the result type's one value for true. 8128 8129 `MODIFY_EXPR' 8130 These nodes represent assignment. The left-hand side is the first 8131 operand; the right-hand side is the second operand. The left-hand 8132 side will be a `VAR_DECL', `INDIRECT_REF', `COMPONENT_REF', or 8133 other lvalue. 8134 8135 These nodes are used to represent not only assignment with `=' but 8136 also compound assignments (like `+='), by reduction to `=' 8137 assignment. In other words, the representation for `i += 3' looks 8138 just like that for `i = i + 3'. 8139 8140 `INIT_EXPR' 8141 These nodes are just like `MODIFY_EXPR', but are used only when a 8142 variable is initialized, rather than assigned to subsequently. 8143 This means that we can assume that the target of the 8144 initialization is not used in computing its own value; any 8145 reference to the lhs in computing the rhs is undefined. 8146 8147 `COMPONENT_REF' 8148 These nodes represent non-static data member accesses. The first 8149 operand is the object (rather than a pointer to it); the second 8150 operand is the `FIELD_DECL' for the data member. The third 8151 operand represents the byte offset of the field, but should not be 8152 used directly; call `component_ref_field_offset' instead. 8153 8154 `COMPOUND_EXPR' 8155 These nodes represent comma-expressions. The first operand is an 8156 expression whose value is computed and thrown away prior to the 8157 evaluation of the second operand. The value of the entire 8158 expression is the value of the second operand. 8159 8160 `COND_EXPR' 8161 These nodes represent `?:' expressions. The first operand is of 8162 boolean or integral type. If it evaluates to a nonzero value, the 8163 second operand should be evaluated, and returned as the value of 8164 the expression. Otherwise, the third operand is evaluated, and 8165 returned as the value of the expression. 8166 8167 The second operand must have the same type as the entire 8168 expression, unless it unconditionally throws an exception or calls 8169 a noreturn function, in which case it should have void type. The 8170 same constraints apply to the third operand. This allows array 8171 bounds checks to be represented conveniently as `(i >= 0 && i < 8172 10) ? i : abort()'. 8173 8174 As a GNU extension, the C language front-ends allow the second 8175 operand of the `?:' operator may be omitted in the source. For 8176 example, `x ? : 3' is equivalent to `x ? x : 3', assuming that `x' 8177 is an expression without side-effects. In the tree 8178 representation, however, the second operand is always present, 8179 possibly protected by `SAVE_EXPR' if the first argument does cause 8180 side-effects. 8181 8182 `CALL_EXPR' 8183 These nodes are used to represent calls to functions, including 8184 non-static member functions. `CALL_EXPR's are implemented as 8185 expression nodes with a variable number of operands. Rather than 8186 using `TREE_OPERAND' to extract them, it is preferable to use the 8187 specialized accessor macros and functions that operate 8188 specifically on `CALL_EXPR' nodes. 8189 8190 `CALL_EXPR_FN' returns a pointer to the function to call; it is 8191 always an expression whose type is a `POINTER_TYPE'. 8192 8193 The number of arguments to the call is returned by 8194 `call_expr_nargs', while the arguments themselves can be accessed 8195 with the `CALL_EXPR_ARG' macro. The arguments are zero-indexed 8196 and numbered left-to-right. You can iterate over the arguments 8197 using `FOR_EACH_CALL_EXPR_ARG', as in: 8198 8199 tree call, arg; 8200 call_expr_arg_iterator iter; 8201 FOR_EACH_CALL_EXPR_ARG (arg, iter, call) 8202 /* arg is bound to successive arguments of call. */ 8203 ...; 8204 8205 For non-static member functions, there will be an operand 8206 corresponding to the `this' pointer. There will always be 8207 expressions corresponding to all of the arguments, even if the 8208 function is declared with default arguments and some arguments are 8209 not explicitly provided at the call sites. 8210 8211 `CALL_EXPR's also have a `CALL_EXPR_STATIC_CHAIN' operand that is 8212 used to implement nested functions. This operand is otherwise 8213 null. 8214 8215 `STMT_EXPR' 8216 These nodes are used to represent GCC's statement-expression 8217 extension. The statement-expression extension allows code like 8218 this: 8219 int f() { return ({ int j; j = 3; j + 7; }); } 8220 In other words, an sequence of statements may occur where a single 8221 expression would normally appear. The `STMT_EXPR' node represents 8222 such an expression. The `STMT_EXPR_STMT' gives the statement 8223 contained in the expression. The value of the expression is the 8224 value of the last sub-statement in the body. More precisely, the 8225 value is the value computed by the last statement nested inside 8226 `BIND_EXPR', `TRY_FINALLY_EXPR', or `TRY_CATCH_EXPR'. For 8227 example, in: 8228 ({ 3; }) 8229 the value is `3' while in: 8230 ({ if (x) { 3; } }) 8231 there is no value. If the `STMT_EXPR' does not yield a value, 8232 it's type will be `void'. 8233 8234 `BIND_EXPR' 8235 These nodes represent local blocks. The first operand is a list of 8236 variables, connected via their `TREE_CHAIN' field. These will 8237 never require cleanups. The scope of these variables is just the 8238 body of the `BIND_EXPR'. The body of the `BIND_EXPR' is the 8239 second operand. 8240 8241 `LOOP_EXPR' 8242 These nodes represent "infinite" loops. The `LOOP_EXPR_BODY' 8243 represents the body of the loop. It should be executed forever, 8244 unless an `EXIT_EXPR' is encountered. 8245 8246 `EXIT_EXPR' 8247 These nodes represent conditional exits from the nearest enclosing 8248 `LOOP_EXPR'. The single operand is the condition; if it is 8249 nonzero, then the loop should be exited. An `EXIT_EXPR' will only 8250 appear within a `LOOP_EXPR'. 8251 8252 `CLEANUP_POINT_EXPR' 8253 These nodes represent full-expressions. The single operand is an 8254 expression to evaluate. Any destructor calls engendered by the 8255 creation of temporaries during the evaluation of that expression 8256 should be performed immediately after the expression is evaluated. 8257 8258 `CONSTRUCTOR' 8259 These nodes represent the brace-enclosed initializers for a 8260 structure or array. The first operand is reserved for use by the 8261 back end. The second operand is a `TREE_LIST'. If the 8262 `TREE_TYPE' of the `CONSTRUCTOR' is a `RECORD_TYPE' or 8263 `UNION_TYPE', then the `TREE_PURPOSE' of each node in the 8264 `TREE_LIST' will be a `FIELD_DECL' and the `TREE_VALUE' of each 8265 node will be the expression used to initialize that field. 8266 8267 If the `TREE_TYPE' of the `CONSTRUCTOR' is an `ARRAY_TYPE', then 8268 the `TREE_PURPOSE' of each element in the `TREE_LIST' will be an 8269 `INTEGER_CST' or a `RANGE_EXPR' of two `INTEGER_CST's. A single 8270 `INTEGER_CST' indicates which element of the array (indexed from 8271 zero) is being assigned to. A `RANGE_EXPR' indicates an inclusive 8272 range of elements to initialize. In both cases the `TREE_VALUE' 8273 is the corresponding initializer. It is re-evaluated for each 8274 element of a `RANGE_EXPR'. If the `TREE_PURPOSE' is `NULL_TREE', 8275 then the initializer is for the next available array element. 8276 8277 In the front end, you should not depend on the fields appearing in 8278 any particular order. However, in the middle end, fields must 8279 appear in declaration order. You should not assume that all 8280 fields will be represented. Unrepresented fields will be set to 8281 zero. 8282 8283 `COMPOUND_LITERAL_EXPR' 8284 These nodes represent ISO C99 compound literals. The 8285 `COMPOUND_LITERAL_EXPR_DECL_STMT' is a `DECL_STMT' containing an 8286 anonymous `VAR_DECL' for the unnamed object represented by the 8287 compound literal; the `DECL_INITIAL' of that `VAR_DECL' is a 8288 `CONSTRUCTOR' representing the brace-enclosed list of initializers 8289 in the compound literal. That anonymous `VAR_DECL' can also be 8290 accessed directly by the `COMPOUND_LITERAL_EXPR_DECL' macro. 8291 8292 `SAVE_EXPR' 8293 A `SAVE_EXPR' represents an expression (possibly involving 8294 side-effects) that is used more than once. The side-effects should 8295 occur only the first time the expression is evaluated. Subsequent 8296 uses should just reuse the computed value. The first operand to 8297 the `SAVE_EXPR' is the expression to evaluate. The side-effects 8298 should be executed where the `SAVE_EXPR' is first encountered in a 8299 depth-first preorder traversal of the expression tree. 8300 8301 `TARGET_EXPR' 8302 A `TARGET_EXPR' represents a temporary object. The first operand 8303 is a `VAR_DECL' for the temporary variable. The second operand is 8304 the initializer for the temporary. The initializer is evaluated 8305 and, if non-void, copied (bitwise) into the temporary. If the 8306 initializer is void, that means that it will perform the 8307 initialization itself. 8308 8309 Often, a `TARGET_EXPR' occurs on the right-hand side of an 8310 assignment, or as the second operand to a comma-expression which is 8311 itself the right-hand side of an assignment, etc. In this case, 8312 we say that the `TARGET_EXPR' is "normal"; otherwise, we say it is 8313 "orphaned". For a normal `TARGET_EXPR' the temporary variable 8314 should be treated as an alias for the left-hand side of the 8315 assignment, rather than as a new temporary variable. 8316 8317 The third operand to the `TARGET_EXPR', if present, is a 8318 cleanup-expression (i.e., destructor call) for the temporary. If 8319 this expression is orphaned, then this expression must be executed 8320 when the statement containing this expression is complete. These 8321 cleanups must always be executed in the order opposite to that in 8322 which they were encountered. Note that if a temporary is created 8323 on one branch of a conditional operator (i.e., in the second or 8324 third operand to a `COND_EXPR'), the cleanup must be run only if 8325 that branch is actually executed. 8326 8327 See `STMT_IS_FULL_EXPR_P' for more information about running these 8328 cleanups. 8329 8330 `AGGR_INIT_EXPR' 8331 An `AGGR_INIT_EXPR' represents the initialization as the return 8332 value of a function call, or as the result of a constructor. An 8333 `AGGR_INIT_EXPR' will only appear as a full-expression, or as the 8334 second operand of a `TARGET_EXPR'. `AGGR_INIT_EXPR's have a 8335 representation similar to that of `CALL_EXPR's. You can use the 8336 `AGGR_INIT_EXPR_FN' and `AGGR_INIT_EXPR_ARG' macros to access the 8337 function to call and the arguments to pass. 8338 8339 If `AGGR_INIT_VIA_CTOR_P' holds of the `AGGR_INIT_EXPR', then the 8340 initialization is via a constructor call. The address of the 8341 `AGGR_INIT_EXPR_SLOT' operand, which is always a `VAR_DECL', is 8342 taken, and this value replaces the first argument in the argument 8343 list. 8344 8345 In either case, the expression is void. 8346 8347 `VA_ARG_EXPR' 8348 This node is used to implement support for the C/C++ variable 8349 argument-list mechanism. It represents expressions like `va_arg 8350 (ap, type)'. Its `TREE_TYPE' yields the tree representation for 8351 `type' and its sole argument yields the representation for `ap'. 8352 8353 `CHANGE_DYNAMIC_TYPE_EXPR' 8354 Indicates the special aliasing required by C++ placement new. It 8355 has two operands: a type and a location. It means that the 8356 dynamic type of the location is changing to be the specified type. 8357 The alias analysis code takes this into account when doing type 8358 based alias analysis. 8359 8360 `OMP_PARALLEL' 8361 Represents `#pragma omp parallel [clause1 ... clauseN]'. It has 8362 four operands: 8363 8364 Operand `OMP_PARALLEL_BODY' is valid while in GENERIC and High 8365 GIMPLE forms. It contains the body of code to be executed by all 8366 the threads. During GIMPLE lowering, this operand becomes `NULL' 8367 and the body is emitted linearly after `OMP_PARALLEL'. 8368 8369 Operand `OMP_PARALLEL_CLAUSES' is the list of clauses associated 8370 with the directive. 8371 8372 Operand `OMP_PARALLEL_FN' is created by `pass_lower_omp', it 8373 contains the `FUNCTION_DECL' for the function that will contain 8374 the body of the parallel region. 8375 8376 Operand `OMP_PARALLEL_DATA_ARG' is also created by 8377 `pass_lower_omp'. If there are shared variables to be communicated 8378 to the children threads, this operand will contain the `VAR_DECL' 8379 that contains all the shared values and variables. 8380 8381 `OMP_FOR' 8382 Represents `#pragma omp for [clause1 ... clauseN]'. It has 5 8383 operands: 8384 8385 Operand `OMP_FOR_BODY' contains the loop body. 8386 8387 Operand `OMP_FOR_CLAUSES' is the list of clauses associated with 8388 the directive. 8389 8390 Operand `OMP_FOR_INIT' is the loop initialization code of the form 8391 `VAR = N1'. 8392 8393 Operand `OMP_FOR_COND' is the loop conditional expression of the 8394 form `VAR {<,>,<=,>=} N2'. 8395 8396 Operand `OMP_FOR_INCR' is the loop index increment of the form 8397 `VAR {+=,-=} INCR'. 8398 8399 Operand `OMP_FOR_PRE_BODY' contains side-effect code from operands 8400 `OMP_FOR_INIT', `OMP_FOR_COND' and `OMP_FOR_INC'. These 8401 side-effects are part of the `OMP_FOR' block but must be evaluated 8402 before the start of loop body. 8403 8404 The loop index variable `VAR' must be a signed integer variable, 8405 which is implicitly private to each thread. Bounds `N1' and `N2' 8406 and the increment expression `INCR' are required to be loop 8407 invariant integer expressions that are evaluated without any 8408 synchronization. The evaluation order, frequency of evaluation and 8409 side-effects are unspecified by the standard. 8410 8411 `OMP_SECTIONS' 8412 Represents `#pragma omp sections [clause1 ... clauseN]'. 8413 8414 Operand `OMP_SECTIONS_BODY' contains the sections body, which in 8415 turn contains a set of `OMP_SECTION' nodes for each of the 8416 concurrent sections delimited by `#pragma omp section'. 8417 8418 Operand `OMP_SECTIONS_CLAUSES' is the list of clauses associated 8419 with the directive. 8420 8421 `OMP_SECTION' 8422 Section delimiter for `OMP_SECTIONS'. 8423 8424 `OMP_SINGLE' 8425 Represents `#pragma omp single'. 8426 8427 Operand `OMP_SINGLE_BODY' contains the body of code to be executed 8428 by a single thread. 8429 8430 Operand `OMP_SINGLE_CLAUSES' is the list of clauses associated 8431 with the directive. 8432 8433 `OMP_MASTER' 8434 Represents `#pragma omp master'. 8435 8436 Operand `OMP_MASTER_BODY' contains the body of code to be executed 8437 by the master thread. 8438 8439 `OMP_ORDERED' 8440 Represents `#pragma omp ordered'. 8441 8442 Operand `OMP_ORDERED_BODY' contains the body of code to be 8443 executed in the sequential order dictated by the loop index 8444 variable. 8445 8446 `OMP_CRITICAL' 8447 Represents `#pragma omp critical [name]'. 8448 8449 Operand `OMP_CRITICAL_BODY' is the critical section. 8450 8451 Operand `OMP_CRITICAL_NAME' is an optional identifier to label the 8452 critical section. 8453 8454 `OMP_RETURN' 8455 This does not represent any OpenMP directive, it is an artificial 8456 marker to indicate the end of the body of an OpenMP. It is used by 8457 the flow graph (`tree-cfg.c') and OpenMP region building code 8458 (`omp-low.c'). 8459 8460 `OMP_CONTINUE' 8461 Similarly, this instruction does not represent an OpenMP 8462 directive, it is used by `OMP_FOR' and `OMP_SECTIONS' to mark the 8463 place where the code needs to loop to the next iteration (in the 8464 case of `OMP_FOR') or the next section (in the case of 8465 `OMP_SECTIONS'). 8466 8467 In some cases, `OMP_CONTINUE' is placed right before `OMP_RETURN'. 8468 But if there are cleanups that need to occur right after the 8469 looping body, it will be emitted between `OMP_CONTINUE' and 8470 `OMP_RETURN'. 8471 8472 `OMP_ATOMIC' 8473 Represents `#pragma omp atomic'. 8474 8475 Operand 0 is the address at which the atomic operation is to be 8476 performed. 8477 8478 Operand 1 is the expression to evaluate. The gimplifier tries 8479 three alternative code generation strategies. Whenever possible, 8480 an atomic update built-in is used. If that fails, a 8481 compare-and-swap loop is attempted. If that also fails, a regular 8482 critical section around the expression is used. 8483 8484 `OMP_CLAUSE' 8485 Represents clauses associated with one of the `OMP_' directives. 8486 Clauses are represented by separate sub-codes defined in `tree.h'. 8487 Clauses codes can be one of: `OMP_CLAUSE_PRIVATE', 8488 `OMP_CLAUSE_SHARED', `OMP_CLAUSE_FIRSTPRIVATE', 8489 `OMP_CLAUSE_LASTPRIVATE', `OMP_CLAUSE_COPYIN', 8490 `OMP_CLAUSE_COPYPRIVATE', `OMP_CLAUSE_IF', 8491 `OMP_CLAUSE_NUM_THREADS', `OMP_CLAUSE_SCHEDULE', 8492 `OMP_CLAUSE_NOWAIT', `OMP_CLAUSE_ORDERED', `OMP_CLAUSE_DEFAULT', 8493 and `OMP_CLAUSE_REDUCTION'. Each code represents the 8494 corresponding OpenMP clause. 8495 8496 Clauses associated with the same directive are chained together 8497 via `OMP_CLAUSE_CHAIN'. Those clauses that accept a list of 8498 variables are restricted to exactly one, accessed with 8499 `OMP_CLAUSE_VAR'. Therefore, multiple variables under the same 8500 clause `C' need to be represented as multiple `C' clauses chained 8501 together. This facilitates adding new clauses during compilation. 8502 8503 `VEC_LSHIFT_EXPR' 8504 8505 `VEC_RSHIFT_EXPR' 8506 These nodes represent whole vector left and right shifts, 8507 respectively. The first operand is the vector to shift; it will 8508 always be of vector type. The second operand is an expression for 8509 the number of bits by which to shift. Note that the result is 8510 undefined if the second operand is larger than or equal to the 8511 first operand's type size. 8512 8513 `VEC_WIDEN_MULT_HI_EXPR' 8514 8515 `VEC_WIDEN_MULT_LO_EXPR' 8516 These nodes represent widening vector multiplication of the high 8517 and low parts of the two input vectors, respectively. Their 8518 operands are vectors that contain the same number of elements 8519 (`N') of the same integral type. The result is a vector that 8520 contains half as many elements, of an integral type whose size is 8521 twice as wide. In the case of `VEC_WIDEN_MULT_HI_EXPR' the high 8522 `N/2' elements of the two vector are multiplied to produce the 8523 vector of `N/2' products. In the case of `VEC_WIDEN_MULT_LO_EXPR' 8524 the low `N/2' elements of the two vector are multiplied to produce 8525 the vector of `N/2' products. 8526 8527 `VEC_UNPACK_HI_EXPR' 8528 8529 `VEC_UNPACK_LO_EXPR' 8530 These nodes represent unpacking of the high and low parts of the 8531 input vector, respectively. The single operand is a vector that 8532 contains `N' elements of the same integral or floating point type. 8533 The result is a vector that contains half as many elements, of an 8534 integral or floating point type whose size is twice as wide. In 8535 the case of `VEC_UNPACK_HI_EXPR' the high `N/2' elements of the 8536 vector are extracted and widened (promoted). In the case of 8537 `VEC_UNPACK_LO_EXPR' the low `N/2' elements of the vector are 8538 extracted and widened (promoted). 8539 8540 `VEC_UNPACK_FLOAT_HI_EXPR' 8541 8542 `VEC_UNPACK_FLOAT_LO_EXPR' 8543 These nodes represent unpacking of the high and low parts of the 8544 input vector, where the values are converted from fixed point to 8545 floating point. The single operand is a vector that contains `N' 8546 elements of the same integral type. The result is a vector that 8547 contains half as many elements of a floating point type whose size 8548 is twice as wide. In the case of `VEC_UNPACK_HI_EXPR' the high 8549 `N/2' elements of the vector are extracted, converted and widened. 8550 In the case of `VEC_UNPACK_LO_EXPR' the low `N/2' elements of the 8551 vector are extracted, converted and widened. 8552 8553 `VEC_PACK_TRUNC_EXPR' 8554 This node represents packing of truncated elements of the two 8555 input vectors into the output vector. Input operands are vectors 8556 that contain the same number of elements of the same integral or 8557 floating point type. The result is a vector that contains twice 8558 as many elements of an integral or floating point type whose size 8559 is half as wide. The elements of the two vectors are demoted and 8560 merged (concatenated) to form the output vector. 8561 8562 `VEC_PACK_SAT_EXPR' 8563 This node represents packing of elements of the two input vectors 8564 into the output vector using saturation. Input operands are 8565 vectors that contain the same number of elements of the same 8566 integral type. The result is a vector that contains twice as many 8567 elements of an integral type whose size is half as wide. The 8568 elements of the two vectors are demoted and merged (concatenated) 8569 to form the output vector. 8570 8571 `VEC_PACK_FIX_TRUNC_EXPR' 8572 This node represents packing of elements of the two input vectors 8573 into the output vector, where the values are converted from 8574 floating point to fixed point. Input operands are vectors that 8575 contain the same number of elements of a floating point type. The 8576 result is a vector that contains twice as many elements of an 8577 integral type whose size is half as wide. The elements of the two 8578 vectors are merged (concatenated) to form the output vector. 8579 8580 `VEC_EXTRACT_EVEN_EXPR' 8581 8582 `VEC_EXTRACT_ODD_EXPR' 8583 These nodes represent extracting of the even/odd elements of the 8584 two input vectors, respectively. Their operands and result are 8585 vectors that contain the same number of elements of the same type. 8586 8587 `VEC_INTERLEAVE_HIGH_EXPR' 8588 8589 `VEC_INTERLEAVE_LOW_EXPR' 8590 These nodes represent merging and interleaving of the high/low 8591 elements of the two input vectors, respectively. The operands and 8592 the result are vectors that contain the same number of elements 8593 (`N') of the same type. In the case of 8594 `VEC_INTERLEAVE_HIGH_EXPR', the high `N/2' elements of the first 8595 input vector are interleaved with the high `N/2' elements of the 8596 second input vector. In the case of `VEC_INTERLEAVE_LOW_EXPR', the 8597 low `N/2' elements of the first input vector are interleaved with 8598 the low `N/2' elements of the second input vector. 8599 8600 8601 8602 File: gccint.info, Node: RTL, Next: GENERIC, Prev: Trees, Up: Top 8603 8604 10 RTL Representation 8605 ********************* 8606 8607 Most of the work of the compiler is done on an intermediate 8608 representation called register transfer language. In this language, 8609 the instructions to be output are described, pretty much one by one, in 8610 an algebraic form that describes what the instruction does. 8611 8612 RTL is inspired by Lisp lists. It has both an internal form, made up 8613 of structures that point at other structures, and a textual form that 8614 is used in the machine description and in printed debugging dumps. The 8615 textual form uses nested parentheses to indicate the pointers in the 8616 internal form. 8617 8618 * Menu: 8619 8620 * RTL Objects:: Expressions vs vectors vs strings vs integers. 8621 * RTL Classes:: Categories of RTL expression objects, and their structure. 8622 * Accessors:: Macros to access expression operands or vector elts. 8623 * Special Accessors:: Macros to access specific annotations on RTL. 8624 * Flags:: Other flags in an RTL expression. 8625 * Machine Modes:: Describing the size and format of a datum. 8626 * Constants:: Expressions with constant values. 8627 * Regs and Memory:: Expressions representing register contents or memory. 8628 * Arithmetic:: Expressions representing arithmetic on other expressions. 8629 * Comparisons:: Expressions representing comparison of expressions. 8630 * Bit-Fields:: Expressions representing bit-fields in memory or reg. 8631 * Vector Operations:: Expressions involving vector datatypes. 8632 * Conversions:: Extending, truncating, floating or fixing. 8633 * RTL Declarations:: Declaring volatility, constancy, etc. 8634 * Side Effects:: Expressions for storing in registers, etc. 8635 * Incdec:: Embedded side-effects for autoincrement addressing. 8636 * Assembler:: Representing `asm' with operands. 8637 * Insns:: Expression types for entire insns. 8638 * Calls:: RTL representation of function call insns. 8639 * Sharing:: Some expressions are unique; others *must* be copied. 8640 * Reading RTL:: Reading textual RTL from a file. 8641 8642 8643 File: gccint.info, Node: RTL Objects, Next: RTL Classes, Up: RTL 8644 8645 10.1 RTL Object Types 8646 ===================== 8647 8648 RTL uses five kinds of objects: expressions, integers, wide integers, 8649 strings and vectors. Expressions are the most important ones. An RTL 8650 expression ("RTX", for short) is a C structure, but it is usually 8651 referred to with a pointer; a type that is given the typedef name `rtx'. 8652 8653 An integer is simply an `int'; their written form uses decimal digits. 8654 A wide integer is an integral object whose type is `HOST_WIDE_INT'; 8655 their written form uses decimal digits. 8656 8657 A string is a sequence of characters. In core it is represented as a 8658 `char *' in usual C fashion, and it is written in C syntax as well. 8659 However, strings in RTL may never be null. If you write an empty 8660 string in a machine description, it is represented in core as a null 8661 pointer rather than as a pointer to a null character. In certain 8662 contexts, these null pointers instead of strings are valid. Within RTL 8663 code, strings are most commonly found inside `symbol_ref' expressions, 8664 but they appear in other contexts in the RTL expressions that make up 8665 machine descriptions. 8666 8667 In a machine description, strings are normally written with double 8668 quotes, as you would in C. However, strings in machine descriptions may 8669 extend over many lines, which is invalid C, and adjacent string 8670 constants are not concatenated as they are in C. Any string constant 8671 may be surrounded with a single set of parentheses. Sometimes this 8672 makes the machine description easier to read. 8673 8674 There is also a special syntax for strings, which can be useful when C 8675 code is embedded in a machine description. Wherever a string can 8676 appear, it is also valid to write a C-style brace block. The entire 8677 brace block, including the outermost pair of braces, is considered to be 8678 the string constant. Double quote characters inside the braces are not 8679 special. Therefore, if you write string constants in the C code, you 8680 need not escape each quote character with a backslash. 8681 8682 A vector contains an arbitrary number of pointers to expressions. The 8683 number of elements in the vector is explicitly present in the vector. 8684 The written form of a vector consists of square brackets (`[...]') 8685 surrounding the elements, in sequence and with whitespace separating 8686 them. Vectors of length zero are not created; null pointers are used 8687 instead. 8688 8689 Expressions are classified by "expression codes" (also called RTX 8690 codes). The expression code is a name defined in `rtl.def', which is 8691 also (in uppercase) a C enumeration constant. The possible expression 8692 codes and their meanings are machine-independent. The code of an RTX 8693 can be extracted with the macro `GET_CODE (X)' and altered with 8694 `PUT_CODE (X, NEWCODE)'. 8695 8696 The expression code determines how many operands the expression 8697 contains, and what kinds of objects they are. In RTL, unlike Lisp, you 8698 cannot tell by looking at an operand what kind of object it is. 8699 Instead, you must know from its context--from the expression code of 8700 the containing expression. For example, in an expression of code 8701 `subreg', the first operand is to be regarded as an expression and the 8702 second operand as an integer. In an expression of code `plus', there 8703 are two operands, both of which are to be regarded as expressions. In 8704 a `symbol_ref' expression, there is one operand, which is to be 8705 regarded as a string. 8706 8707 Expressions are written as parentheses containing the name of the 8708 expression type, its flags and machine mode if any, and then the 8709 operands of the expression (separated by spaces). 8710 8711 Expression code names in the `md' file are written in lowercase, but 8712 when they appear in C code they are written in uppercase. In this 8713 manual, they are shown as follows: `const_int'. 8714 8715 In a few contexts a null pointer is valid where an expression is 8716 normally wanted. The written form of this is `(nil)'. 8717 8718 8719 File: gccint.info, Node: RTL Classes, Next: Accessors, Prev: RTL Objects, Up: RTL 8720 8721 10.2 RTL Classes and Formats 8722 ============================ 8723 8724 The various expression codes are divided into several "classes", which 8725 are represented by single characters. You can determine the class of 8726 an RTX code with the macro `GET_RTX_CLASS (CODE)'. Currently, 8727 `rtl.def' defines these classes: 8728 8729 `RTX_OBJ' 8730 An RTX code that represents an actual object, such as a register 8731 (`REG') or a memory location (`MEM', `SYMBOL_REF'). `LO_SUM') is 8732 also included; instead, `SUBREG' and `STRICT_LOW_PART' are not in 8733 this class, but in class `x'. 8734 8735 `RTX_CONST_OBJ' 8736 An RTX code that represents a constant object. `HIGH' is also 8737 included in this class. 8738 8739 `RTX_COMPARE' 8740 An RTX code for a non-symmetric comparison, such as `GEU' or `LT'. 8741 8742 `RTX_COMM_COMPARE' 8743 An RTX code for a symmetric (commutative) comparison, such as `EQ' 8744 or `ORDERED'. 8745 8746 `RTX_UNARY' 8747 An RTX code for a unary arithmetic operation, such as `NEG', 8748 `NOT', or `ABS'. This category also includes value extension 8749 (sign or zero) and conversions between integer and floating point. 8750 8751 `RTX_COMM_ARITH' 8752 An RTX code for a commutative binary operation, such as `PLUS' or 8753 `AND'. `NE' and `EQ' are comparisons, so they have class `<'. 8754 8755 `RTX_BIN_ARITH' 8756 An RTX code for a non-commutative binary operation, such as 8757 `MINUS', `DIV', or `ASHIFTRT'. 8758 8759 `RTX_BITFIELD_OPS' 8760 An RTX code for a bit-field operation. Currently only 8761 `ZERO_EXTRACT' and `SIGN_EXTRACT'. These have three inputs and 8762 are lvalues (so they can be used for insertion as well). *Note 8763 Bit-Fields::. 8764 8765 `RTX_TERNARY' 8766 An RTX code for other three input operations. Currently only 8767 `IF_THEN_ELSE' and `VEC_MERGE'. 8768 8769 `RTX_INSN' 8770 An RTX code for an entire instruction: `INSN', `JUMP_INSN', and 8771 `CALL_INSN'. *Note Insns::. 8772 8773 `RTX_MATCH' 8774 An RTX code for something that matches in insns, such as 8775 `MATCH_DUP'. These only occur in machine descriptions. 8776 8777 `RTX_AUTOINC' 8778 An RTX code for an auto-increment addressing mode, such as 8779 `POST_INC'. 8780 8781 `RTX_EXTRA' 8782 All other RTX codes. This category includes the remaining codes 8783 used only in machine descriptions (`DEFINE_*', etc.). It also 8784 includes all the codes describing side effects (`SET', `USE', 8785 `CLOBBER', etc.) and the non-insns that may appear on an insn 8786 chain, such as `NOTE', `BARRIER', and `CODE_LABEL'. `SUBREG' is 8787 also part of this class. 8788 8789 For each expression code, `rtl.def' specifies the number of contained 8790 objects and their kinds using a sequence of characters called the 8791 "format" of the expression code. For example, the format of `subreg' 8792 is `ei'. 8793 8794 These are the most commonly used format characters: 8795 8796 `e' 8797 An expression (actually a pointer to an expression). 8798 8799 `i' 8800 An integer. 8801 8802 `w' 8803 A wide integer. 8804 8805 `s' 8806 A string. 8807 8808 `E' 8809 A vector of expressions. 8810 8811 A few other format characters are used occasionally: 8812 8813 `u' 8814 `u' is equivalent to `e' except that it is printed differently in 8815 debugging dumps. It is used for pointers to insns. 8816 8817 `n' 8818 `n' is equivalent to `i' except that it is printed differently in 8819 debugging dumps. It is used for the line number or code number of 8820 a `note' insn. 8821 8822 `S' 8823 `S' indicates a string which is optional. In the RTL objects in 8824 core, `S' is equivalent to `s', but when the object is read, from 8825 an `md' file, the string value of this operand may be omitted. An 8826 omitted string is taken to be the null string. 8827 8828 `V' 8829 `V' indicates a vector which is optional. In the RTL objects in 8830 core, `V' is equivalent to `E', but when the object is read from 8831 an `md' file, the vector value of this operand may be omitted. An 8832 omitted vector is effectively the same as a vector of no elements. 8833 8834 `B' 8835 `B' indicates a pointer to basic block structure. 8836 8837 `0' 8838 `0' means a slot whose contents do not fit any normal category. 8839 `0' slots are not printed at all in dumps, and are often used in 8840 special ways by small parts of the compiler. 8841 8842 There are macros to get the number of operands and the format of an 8843 expression code: 8844 8845 `GET_RTX_LENGTH (CODE)' 8846 Number of operands of an RTX of code CODE. 8847 8848 `GET_RTX_FORMAT (CODE)' 8849 The format of an RTX of code CODE, as a C string. 8850 8851 Some classes of RTX codes always have the same format. For example, it 8852 is safe to assume that all comparison operations have format `ee'. 8853 8854 `1' 8855 All codes of this class have format `e'. 8856 8857 `<' 8858 `c' 8859 `2' 8860 All codes of these classes have format `ee'. 8861 8862 `b' 8863 `3' 8864 All codes of these classes have format `eee'. 8865 8866 `i' 8867 All codes of this class have formats that begin with `iuueiee'. 8868 *Note Insns::. Note that not all RTL objects linked onto an insn 8869 chain are of class `i'. 8870 8871 `o' 8872 `m' 8873 `x' 8874 You can make no assumptions about the format of these codes. 8875 8876 8877 File: gccint.info, Node: Accessors, Next: Special Accessors, Prev: RTL Classes, Up: RTL 8878 8879 10.3 Access to Operands 8880 ======================= 8881 8882 Operands of expressions are accessed using the macros `XEXP', `XINT', 8883 `XWINT' and `XSTR'. Each of these macros takes two arguments: an 8884 expression-pointer (RTX) and an operand number (counting from zero). 8885 Thus, 8886 8887 XEXP (X, 2) 8888 8889 accesses operand 2 of expression X, as an expression. 8890 8891 XINT (X, 2) 8892 8893 accesses the same operand as an integer. `XSTR', used in the same 8894 fashion, would access it as a string. 8895 8896 Any operand can be accessed as an integer, as an expression or as a 8897 string. You must choose the correct method of access for the kind of 8898 value actually stored in the operand. You would do this based on the 8899 expression code of the containing expression. That is also how you 8900 would know how many operands there are. 8901 8902 For example, if X is a `subreg' expression, you know that it has two 8903 operands which can be correctly accessed as `XEXP (X, 0)' and `XINT (X, 8904 1)'. If you did `XINT (X, 0)', you would get the address of the 8905 expression operand but cast as an integer; that might occasionally be 8906 useful, but it would be cleaner to write `(int) XEXP (X, 0)'. `XEXP 8907 (X, 1)' would also compile without error, and would return the second, 8908 integer operand cast as an expression pointer, which would probably 8909 result in a crash when accessed. Nothing stops you from writing `XEXP 8910 (X, 28)' either, but this will access memory past the end of the 8911 expression with unpredictable results. 8912 8913 Access to operands which are vectors is more complicated. You can use 8914 the macro `XVEC' to get the vector-pointer itself, or the macros 8915 `XVECEXP' and `XVECLEN' to access the elements and length of a vector. 8916 8917 `XVEC (EXP, IDX)' 8918 Access the vector-pointer which is operand number IDX in EXP. 8919 8920 `XVECLEN (EXP, IDX)' 8921 Access the length (number of elements) in the vector which is in 8922 operand number IDX in EXP. This value is an `int'. 8923 8924 `XVECEXP (EXP, IDX, ELTNUM)' 8925 Access element number ELTNUM in the vector which is in operand 8926 number IDX in EXP. This value is an RTX. 8927 8928 It is up to you to make sure that ELTNUM is not negative and is 8929 less than `XVECLEN (EXP, IDX)'. 8930 8931 All the macros defined in this section expand into lvalues and 8932 therefore can be used to assign the operands, lengths and vector 8933 elements as well as to access them. 8934 8935 8936 File: gccint.info, Node: Special Accessors, Next: Flags, Prev: Accessors, Up: RTL 8937 8938 10.4 Access to Special Operands 8939 =============================== 8940 8941 Some RTL nodes have special annotations associated with them. 8942 8943 `MEM' 8944 8945 `MEM_ALIAS_SET (X)' 8946 If 0, X is not in any alias set, and may alias anything. 8947 Otherwise, X can only alias `MEM's in a conflicting alias 8948 set. This value is set in a language-dependent manner in the 8949 front-end, and should not be altered in the back-end. In 8950 some front-ends, these numbers may correspond in some way to 8951 types, or other language-level entities, but they need not, 8952 and the back-end makes no such assumptions. These set 8953 numbers are tested with `alias_sets_conflict_p'. 8954 8955 `MEM_EXPR (X)' 8956 If this register is known to hold the value of some user-level 8957 declaration, this is that tree node. It may also be a 8958 `COMPONENT_REF', in which case this is some field reference, 8959 and `TREE_OPERAND (X, 0)' contains the declaration, or 8960 another `COMPONENT_REF', or null if there is no compile-time 8961 object associated with the reference. 8962 8963 `MEM_OFFSET (X)' 8964 The offset from the start of `MEM_EXPR' as a `CONST_INT' rtx. 8965 8966 `MEM_SIZE (X)' 8967 The size in bytes of the memory reference as a `CONST_INT' 8968 rtx. This is mostly relevant for `BLKmode' references as 8969 otherwise the size is implied by the mode. 8970 8971 `MEM_ALIGN (X)' 8972 The known alignment in bits of the memory reference. 8973 8974 `REG' 8975 8976 `ORIGINAL_REGNO (X)' 8977 This field holds the number the register "originally" had; 8978 for a pseudo register turned into a hard reg this will hold 8979 the old pseudo register number. 8980 8981 `REG_EXPR (X)' 8982 If this register is known to hold the value of some user-level 8983 declaration, this is that tree node. 8984 8985 `REG_OFFSET (X)' 8986 If this register is known to hold the value of some user-level 8987 declaration, this is the offset into that logical storage. 8988 8989 `SYMBOL_REF' 8990 8991 `SYMBOL_REF_DECL (X)' 8992 If the `symbol_ref' X was created for a `VAR_DECL' or a 8993 `FUNCTION_DECL', that tree is recorded here. If this value is 8994 null, then X was created by back end code generation routines, 8995 and there is no associated front end symbol table entry. 8996 8997 `SYMBOL_REF_DECL' may also point to a tree of class `'c'', 8998 that is, some sort of constant. In this case, the 8999 `symbol_ref' is an entry in the per-file constant pool; 9000 again, there is no associated front end symbol table entry. 9001 9002 `SYMBOL_REF_CONSTANT (X)' 9003 If `CONSTANT_POOL_ADDRESS_P (X)' is true, this is the constant 9004 pool entry for X. It is null otherwise. 9005 9006 `SYMBOL_REF_DATA (X)' 9007 A field of opaque type used to store `SYMBOL_REF_DECL' or 9008 `SYMBOL_REF_CONSTANT'. 9009 9010 `SYMBOL_REF_FLAGS (X)' 9011 In a `symbol_ref', this is used to communicate various 9012 predicates about the symbol. Some of these are common enough 9013 to be computed by common code, some are specific to the 9014 target. The common bits are: 9015 9016 `SYMBOL_FLAG_FUNCTION' 9017 Set if the symbol refers to a function. 9018 9019 `SYMBOL_FLAG_LOCAL' 9020 Set if the symbol is local to this "module". See 9021 `TARGET_BINDS_LOCAL_P'. 9022 9023 `SYMBOL_FLAG_EXTERNAL' 9024 Set if this symbol is not defined in this translation 9025 unit. Note that this is not the inverse of 9026 `SYMBOL_FLAG_LOCAL'. 9027 9028 `SYMBOL_FLAG_SMALL' 9029 Set if the symbol is located in the small data section. 9030 See `TARGET_IN_SMALL_DATA_P'. 9031 9032 `SYMBOL_REF_TLS_MODEL (X)' 9033 This is a multi-bit field accessor that returns the 9034 `tls_model' to be used for a thread-local storage 9035 symbol. It returns zero for non-thread-local symbols. 9036 9037 `SYMBOL_FLAG_HAS_BLOCK_INFO' 9038 Set if the symbol has `SYMBOL_REF_BLOCK' and 9039 `SYMBOL_REF_BLOCK_OFFSET' fields. 9040 9041 `SYMBOL_FLAG_ANCHOR' 9042 Set if the symbol is used as a section anchor. "Section 9043 anchors" are symbols that have a known position within 9044 an `object_block' and that can be used to access nearby 9045 members of that block. They are used to implement 9046 `-fsection-anchors'. 9047 9048 If this flag is set, then `SYMBOL_FLAG_HAS_BLOCK_INFO' 9049 will be too. 9050 9051 Bits beginning with `SYMBOL_FLAG_MACH_DEP' are available for 9052 the target's use. 9053 9054 `SYMBOL_REF_BLOCK (X)' 9055 If `SYMBOL_REF_HAS_BLOCK_INFO_P (X)', this is the `object_block' 9056 structure to which the symbol belongs, or `NULL' if it has not 9057 been assigned a block. 9058 9059 `SYMBOL_REF_BLOCK_OFFSET (X)' 9060 If `SYMBOL_REF_HAS_BLOCK_INFO_P (X)', this is the offset of X from 9061 the first object in `SYMBOL_REF_BLOCK (X)'. The value is negative 9062 if X has not yet been assigned to a block, or it has not been 9063 given an offset within that block. 9064 9065 9066 File: gccint.info, Node: Flags, Next: Machine Modes, Prev: Special Accessors, Up: RTL 9067 9068 10.5 Flags in an RTL Expression 9069 =============================== 9070 9071 RTL expressions contain several flags (one-bit bit-fields) that are 9072 used in certain types of expression. Most often they are accessed with 9073 the following macros, which expand into lvalues. 9074 9075 `CONSTANT_POOL_ADDRESS_P (X)' 9076 Nonzero in a `symbol_ref' if it refers to part of the current 9077 function's constant pool. For most targets these addresses are in 9078 a `.rodata' section entirely separate from the function, but for 9079 some targets the addresses are close to the beginning of the 9080 function. In either case GCC assumes these addresses can be 9081 addressed directly, perhaps with the help of base registers. 9082 Stored in the `unchanging' field and printed as `/u'. 9083 9084 `RTL_CONST_CALL_P (X)' 9085 In a `call_insn' indicates that the insn represents a call to a 9086 const function. Stored in the `unchanging' field and printed as 9087 `/u'. 9088 9089 `RTL_PURE_CALL_P (X)' 9090 In a `call_insn' indicates that the insn represents a call to a 9091 pure function. Stored in the `return_val' field and printed as 9092 `/i'. 9093 9094 `RTL_CONST_OR_PURE_CALL_P (X)' 9095 In a `call_insn', true if `RTL_CONST_CALL_P' or `RTL_PURE_CALL_P' 9096 is true. 9097 9098 `RTL_LOOPING_CONST_OR_PURE_CALL_P (X)' 9099 In a `call_insn' indicates that the insn represents a possibly 9100 infinite looping call to a const or pure function. Stored in the 9101 `call' field and printed as `/c'. Only true if one of 9102 `RTL_CONST_CALL_P' or `RTL_PURE_CALL_P' is true. 9103 9104 `INSN_ANNULLED_BRANCH_P (X)' 9105 In a `jump_insn', `call_insn', or `insn' indicates that the branch 9106 is an annulling one. See the discussion under `sequence' below. 9107 Stored in the `unchanging' field and printed as `/u'. 9108 9109 `INSN_DELETED_P (X)' 9110 In an `insn', `call_insn', `jump_insn', `code_label', `barrier', 9111 or `note', nonzero if the insn has been deleted. Stored in the 9112 `volatil' field and printed as `/v'. 9113 9114 `INSN_FROM_TARGET_P (X)' 9115 In an `insn' or `jump_insn' or `call_insn' in a delay slot of a 9116 branch, indicates that the insn is from the target of the branch. 9117 If the branch insn has `INSN_ANNULLED_BRANCH_P' set, this insn 9118 will only be executed if the branch is taken. For annulled 9119 branches with `INSN_FROM_TARGET_P' clear, the insn will be 9120 executed only if the branch is not taken. When 9121 `INSN_ANNULLED_BRANCH_P' is not set, this insn will always be 9122 executed. Stored in the `in_struct' field and printed as `/s'. 9123 9124 `LABEL_PRESERVE_P (X)' 9125 In a `code_label' or `note', indicates that the label is 9126 referenced by code or data not visible to the RTL of a given 9127 function. Labels referenced by a non-local goto will have this 9128 bit set. Stored in the `in_struct' field and printed as `/s'. 9129 9130 `LABEL_REF_NONLOCAL_P (X)' 9131 In `label_ref' and `reg_label' expressions, nonzero if this is a 9132 reference to a non-local label. Stored in the `volatil' field and 9133 printed as `/v'. 9134 9135 `MEM_IN_STRUCT_P (X)' 9136 In `mem' expressions, nonzero for reference to an entire structure, 9137 union or array, or to a component of one. Zero for references to a 9138 scalar variable or through a pointer to a scalar. If both this 9139 flag and `MEM_SCALAR_P' are clear, then we don't know whether this 9140 `mem' is in a structure or not. Both flags should never be 9141 simultaneously set. Stored in the `in_struct' field and printed 9142 as `/s'. 9143 9144 `MEM_KEEP_ALIAS_SET_P (X)' 9145 In `mem' expressions, 1 if we should keep the alias set for this 9146 mem unchanged when we access a component. Set to 1, for example, 9147 when we are already in a non-addressable component of an aggregate. 9148 Stored in the `jump' field and printed as `/j'. 9149 9150 `MEM_SCALAR_P (X)' 9151 In `mem' expressions, nonzero for reference to a scalar known not 9152 to be a member of a structure, union, or array. Zero for such 9153 references and for indirections through pointers, even pointers 9154 pointing to scalar types. If both this flag and `MEM_IN_STRUCT_P' 9155 are clear, then we don't know whether this `mem' is in a structure 9156 or not. Both flags should never be simultaneously set. Stored in 9157 the `return_val' field and printed as `/i'. 9158 9159 `MEM_VOLATILE_P (X)' 9160 In `mem', `asm_operands', and `asm_input' expressions, nonzero for 9161 volatile memory references. Stored in the `volatil' field and 9162 printed as `/v'. 9163 9164 `MEM_NOTRAP_P (X)' 9165 In `mem', nonzero for memory references that will not trap. 9166 Stored in the `call' field and printed as `/c'. 9167 9168 `MEM_POINTER (X)' 9169 Nonzero in a `mem' if the memory reference holds a pointer. 9170 Stored in the `frame_related' field and printed as `/f'. 9171 9172 `REG_FUNCTION_VALUE_P (X)' 9173 Nonzero in a `reg' if it is the place in which this function's 9174 value is going to be returned. (This happens only in a hard 9175 register.) Stored in the `return_val' field and printed as `/i'. 9176 9177 `REG_POINTER (X)' 9178 Nonzero in a `reg' if the register holds a pointer. Stored in the 9179 `frame_related' field and printed as `/f'. 9180 9181 `REG_USERVAR_P (X)' 9182 In a `reg', nonzero if it corresponds to a variable present in the 9183 user's source code. Zero for temporaries generated internally by 9184 the compiler. Stored in the `volatil' field and printed as `/v'. 9185 9186 The same hard register may be used also for collecting the values 9187 of functions called by this one, but `REG_FUNCTION_VALUE_P' is zero 9188 in this kind of use. 9189 9190 `RTX_FRAME_RELATED_P (X)' 9191 Nonzero in an `insn', `call_insn', `jump_insn', `barrier', or 9192 `set' which is part of a function prologue and sets the stack 9193 pointer, sets the frame pointer, or saves a register. This flag 9194 should also be set on an instruction that sets up a temporary 9195 register to use in place of the frame pointer. Stored in the 9196 `frame_related' field and printed as `/f'. 9197 9198 In particular, on RISC targets where there are limits on the sizes 9199 of immediate constants, it is sometimes impossible to reach the 9200 register save area directly from the stack pointer. In that case, 9201 a temporary register is used that is near enough to the register 9202 save area, and the Canonical Frame Address, i.e., DWARF2's logical 9203 frame pointer, register must (temporarily) be changed to be this 9204 temporary register. So, the instruction that sets this temporary 9205 register must be marked as `RTX_FRAME_RELATED_P'. 9206 9207 If the marked instruction is overly complex (defined in terms of 9208 what `dwarf2out_frame_debug_expr' can handle), you will also have 9209 to create a `REG_FRAME_RELATED_EXPR' note and attach it to the 9210 instruction. This note should contain a simple expression of the 9211 computation performed by this instruction, i.e., one that 9212 `dwarf2out_frame_debug_expr' can handle. 9213 9214 This flag is required for exception handling support on targets 9215 with RTL prologues. 9216 9217 `MEM_READONLY_P (X)' 9218 Nonzero in a `mem', if the memory is statically allocated and 9219 read-only. 9220 9221 Read-only in this context means never modified during the lifetime 9222 of the program, not necessarily in ROM or in write-disabled pages. 9223 A common example of the later is a shared library's global offset 9224 table. This table is initialized by the runtime loader, so the 9225 memory is technically writable, but after control is transfered 9226 from the runtime loader to the application, this memory will never 9227 be subsequently modified. 9228 9229 Stored in the `unchanging' field and printed as `/u'. 9230 9231 `SCHED_GROUP_P (X)' 9232 During instruction scheduling, in an `insn', `call_insn' or 9233 `jump_insn', indicates that the previous insn must be scheduled 9234 together with this insn. This is used to ensure that certain 9235 groups of instructions will not be split up by the instruction 9236 scheduling pass, for example, `use' insns before a `call_insn' may 9237 not be separated from the `call_insn'. Stored in the `in_struct' 9238 field and printed as `/s'. 9239 9240 `SET_IS_RETURN_P (X)' 9241 For a `set', nonzero if it is for a return. Stored in the `jump' 9242 field and printed as `/j'. 9243 9244 `SIBLING_CALL_P (X)' 9245 For a `call_insn', nonzero if the insn is a sibling call. Stored 9246 in the `jump' field and printed as `/j'. 9247 9248 `STRING_POOL_ADDRESS_P (X)' 9249 For a `symbol_ref' expression, nonzero if it addresses this 9250 function's string constant pool. Stored in the `frame_related' 9251 field and printed as `/f'. 9252 9253 `SUBREG_PROMOTED_UNSIGNED_P (X)' 9254 Returns a value greater then zero for a `subreg' that has 9255 `SUBREG_PROMOTED_VAR_P' nonzero if the object being referenced is 9256 kept zero-extended, zero if it is kept sign-extended, and less 9257 then zero if it is extended some other way via the `ptr_extend' 9258 instruction. Stored in the `unchanging' field and `volatil' 9259 field, printed as `/u' and `/v'. This macro may only be used to 9260 get the value it may not be used to change the value. Use 9261 `SUBREG_PROMOTED_UNSIGNED_SET' to change the value. 9262 9263 `SUBREG_PROMOTED_UNSIGNED_SET (X)' 9264 Set the `unchanging' and `volatil' fields in a `subreg' to reflect 9265 zero, sign, or other extension. If `volatil' is zero, then 9266 `unchanging' as nonzero means zero extension and as zero means 9267 sign extension. If `volatil' is nonzero then some other type of 9268 extension was done via the `ptr_extend' instruction. 9269 9270 `SUBREG_PROMOTED_VAR_P (X)' 9271 Nonzero in a `subreg' if it was made when accessing an object that 9272 was promoted to a wider mode in accord with the `PROMOTED_MODE' 9273 machine description macro (*note Storage Layout::). In this case, 9274 the mode of the `subreg' is the declared mode of the object and 9275 the mode of `SUBREG_REG' is the mode of the register that holds 9276 the object. Promoted variables are always either sign- or 9277 zero-extended to the wider mode on every assignment. Stored in 9278 the `in_struct' field and printed as `/s'. 9279 9280 `SYMBOL_REF_USED (X)' 9281 In a `symbol_ref', indicates that X has been used. This is 9282 normally only used to ensure that X is only declared external 9283 once. Stored in the `used' field. 9284 9285 `SYMBOL_REF_WEAK (X)' 9286 In a `symbol_ref', indicates that X has been declared weak. 9287 Stored in the `return_val' field and printed as `/i'. 9288 9289 `SYMBOL_REF_FLAG (X)' 9290 In a `symbol_ref', this is used as a flag for machine-specific 9291 purposes. Stored in the `volatil' field and printed as `/v'. 9292 9293 Most uses of `SYMBOL_REF_FLAG' are historic and may be subsumed by 9294 `SYMBOL_REF_FLAGS'. Certainly use of `SYMBOL_REF_FLAGS' is 9295 mandatory if the target requires more than one bit of storage. 9296 9297 These are the fields to which the above macros refer: 9298 9299 `call' 9300 In a `mem', 1 means that the memory reference will not trap. 9301 9302 In a `call', 1 means that this pure or const call may possibly 9303 infinite loop. 9304 9305 In an RTL dump, this flag is represented as `/c'. 9306 9307 `frame_related' 9308 In an `insn' or `set' expression, 1 means that it is part of a 9309 function prologue and sets the stack pointer, sets the frame 9310 pointer, saves a register, or sets up a temporary register to use 9311 in place of the frame pointer. 9312 9313 In `reg' expressions, 1 means that the register holds a pointer. 9314 9315 In `mem' expressions, 1 means that the memory reference holds a 9316 pointer. 9317 9318 In `symbol_ref' expressions, 1 means that the reference addresses 9319 this function's string constant pool. 9320 9321 In an RTL dump, this flag is represented as `/f'. 9322 9323 `in_struct' 9324 In `mem' expressions, it is 1 if the memory datum referred to is 9325 all or part of a structure or array; 0 if it is (or might be) a 9326 scalar variable. A reference through a C pointer has 0 because 9327 the pointer might point to a scalar variable. This information 9328 allows the compiler to determine something about possible cases of 9329 aliasing. 9330 9331 In `reg' expressions, it is 1 if the register has its entire life 9332 contained within the test expression of some loop. 9333 9334 In `subreg' expressions, 1 means that the `subreg' is accessing an 9335 object that has had its mode promoted from a wider mode. 9336 9337 In `label_ref' expressions, 1 means that the referenced label is 9338 outside the innermost loop containing the insn in which the 9339 `label_ref' was found. 9340 9341 In `code_label' expressions, it is 1 if the label may never be 9342 deleted. This is used for labels which are the target of 9343 non-local gotos. Such a label that would have been deleted is 9344 replaced with a `note' of type `NOTE_INSN_DELETED_LABEL'. 9345 9346 In an `insn' during dead-code elimination, 1 means that the insn is 9347 dead code. 9348 9349 In an `insn' or `jump_insn' during reorg for an insn in the delay 9350 slot of a branch, 1 means that this insn is from the target of the 9351 branch. 9352 9353 In an `insn' during instruction scheduling, 1 means that this insn 9354 must be scheduled as part of a group together with the previous 9355 insn. 9356 9357 In an RTL dump, this flag is represented as `/s'. 9358 9359 `return_val' 9360 In `reg' expressions, 1 means the register contains the value to 9361 be returned by the current function. On machines that pass 9362 parameters in registers, the same register number may be used for 9363 parameters as well, but this flag is not set on such uses. 9364 9365 In `mem' expressions, 1 means the memory reference is to a scalar 9366 known not to be a member of a structure, union, or array. 9367 9368 In `symbol_ref' expressions, 1 means the referenced symbol is weak. 9369 9370 In `call' expressions, 1 means the call is pure. 9371 9372 In an RTL dump, this flag is represented as `/i'. 9373 9374 `jump' 9375 In a `mem' expression, 1 means we should keep the alias set for 9376 this mem unchanged when we access a component. 9377 9378 In a `set', 1 means it is for a return. 9379 9380 In a `call_insn', 1 means it is a sibling call. 9381 9382 In an RTL dump, this flag is represented as `/j'. 9383 9384 `unchanging' 9385 In `reg' and `mem' expressions, 1 means that the value of the 9386 expression never changes. 9387 9388 In `subreg' expressions, it is 1 if the `subreg' references an 9389 unsigned object whose mode has been promoted to a wider mode. 9390 9391 In an `insn' or `jump_insn' in the delay slot of a branch 9392 instruction, 1 means an annulling branch should be used. 9393 9394 In a `symbol_ref' expression, 1 means that this symbol addresses 9395 something in the per-function constant pool. 9396 9397 In a `call_insn' 1 means that this instruction is a call to a const 9398 function. 9399 9400 In an RTL dump, this flag is represented as `/u'. 9401 9402 `used' 9403 This flag is used directly (without an access macro) at the end of 9404 RTL generation for a function, to count the number of times an 9405 expression appears in insns. Expressions that appear more than 9406 once are copied, according to the rules for shared structure 9407 (*note Sharing::). 9408 9409 For a `reg', it is used directly (without an access macro) by the 9410 leaf register renumbering code to ensure that each register is only 9411 renumbered once. 9412 9413 In a `symbol_ref', it indicates that an external declaration for 9414 the symbol has already been written. 9415 9416 `volatil' 9417 In a `mem', `asm_operands', or `asm_input' expression, it is 1 if 9418 the memory reference is volatile. Volatile memory references may 9419 not be deleted, reordered or combined. 9420 9421 In a `symbol_ref' expression, it is used for machine-specific 9422 purposes. 9423 9424 In a `reg' expression, it is 1 if the value is a user-level 9425 variable. 0 indicates an internal compiler temporary. 9426 9427 In an `insn', 1 means the insn has been deleted. 9428 9429 In `label_ref' and `reg_label' expressions, 1 means a reference to 9430 a non-local label. 9431 9432 In an RTL dump, this flag is represented as `/v'. 9433 9434 9435 File: gccint.info, Node: Machine Modes, Next: Constants, Prev: Flags, Up: RTL 9436 9437 10.6 Machine Modes 9438 ================== 9439 9440 A machine mode describes a size of data object and the representation 9441 used for it. In the C code, machine modes are represented by an 9442 enumeration type, `enum machine_mode', defined in `machmode.def'. Each 9443 RTL expression has room for a machine mode and so do certain kinds of 9444 tree expressions (declarations and types, to be precise). 9445 9446 In debugging dumps and machine descriptions, the machine mode of an RTL 9447 expression is written after the expression code with a colon to separate 9448 them. The letters `mode' which appear at the end of each machine mode 9449 name are omitted. For example, `(reg:SI 38)' is a `reg' expression 9450 with machine mode `SImode'. If the mode is `VOIDmode', it is not 9451 written at all. 9452 9453 Here is a table of machine modes. The term "byte" below refers to an 9454 object of `BITS_PER_UNIT' bits (*note Storage Layout::). 9455 9456 `BImode' 9457 "Bit" mode represents a single bit, for predicate registers. 9458 9459 `QImode' 9460 "Quarter-Integer" mode represents a single byte treated as an 9461 integer. 9462 9463 `HImode' 9464 "Half-Integer" mode represents a two-byte integer. 9465 9466 `PSImode' 9467 "Partial Single Integer" mode represents an integer which occupies 9468 four bytes but which doesn't really use all four. On some 9469 machines, this is the right mode to use for pointers. 9470 9471 `SImode' 9472 "Single Integer" mode represents a four-byte integer. 9473 9474 `PDImode' 9475 "Partial Double Integer" mode represents an integer which occupies 9476 eight bytes but which doesn't really use all eight. On some 9477 machines, this is the right mode to use for certain pointers. 9478 9479 `DImode' 9480 "Double Integer" mode represents an eight-byte integer. 9481 9482 `TImode' 9483 "Tetra Integer" (?) mode represents a sixteen-byte integer. 9484 9485 `OImode' 9486 "Octa Integer" (?) mode represents a thirty-two-byte integer. 9487 9488 `QFmode' 9489 "Quarter-Floating" mode represents a quarter-precision (single 9490 byte) floating point number. 9491 9492 `HFmode' 9493 "Half-Floating" mode represents a half-precision (two byte) 9494 floating point number. 9495 9496 `TQFmode' 9497 "Three-Quarter-Floating" (?) mode represents a 9498 three-quarter-precision (three byte) floating point number. 9499 9500 `SFmode' 9501 "Single Floating" mode represents a four byte floating point 9502 number. In the common case, of a processor with IEEE arithmetic 9503 and 8-bit bytes, this is a single-precision IEEE floating point 9504 number; it can also be used for double-precision (on processors 9505 with 16-bit bytes) and single-precision VAX and IBM types. 9506 9507 `DFmode' 9508 "Double Floating" mode represents an eight byte floating point 9509 number. In the common case, of a processor with IEEE arithmetic 9510 and 8-bit bytes, this is a double-precision IEEE floating point 9511 number. 9512 9513 `XFmode' 9514 "Extended Floating" mode represents an IEEE extended floating point 9515 number. This mode only has 80 meaningful bits (ten bytes). Some 9516 processors require such numbers to be padded to twelve bytes, 9517 others to sixteen; this mode is used for either. 9518 9519 `SDmode' 9520 "Single Decimal Floating" mode represents a four byte decimal 9521 floating point number (as distinct from conventional binary 9522 floating point). 9523 9524 `DDmode' 9525 "Double Decimal Floating" mode represents an eight byte decimal 9526 floating point number. 9527 9528 `TDmode' 9529 "Tetra Decimal Floating" mode represents a sixteen byte decimal 9530 floating point number all 128 of whose bits are meaningful. 9531 9532 `TFmode' 9533 "Tetra Floating" mode represents a sixteen byte floating point 9534 number all 128 of whose bits are meaningful. One common use is the 9535 IEEE quad-precision format. 9536 9537 `QQmode' 9538 "Quarter-Fractional" mode represents a single byte treated as a 9539 signed fractional number. The default format is "s.7". 9540 9541 `HQmode' 9542 "Half-Fractional" mode represents a two-byte signed fractional 9543 number. The default format is "s.15". 9544 9545 `SQmode' 9546 "Single Fractional" mode represents a four-byte signed fractional 9547 number. The default format is "s.31". 9548 9549 `DQmode' 9550 "Double Fractional" mode represents an eight-byte signed 9551 fractional number. The default format is "s.63". 9552 9553 `TQmode' 9554 "Tetra Fractional" mode represents a sixteen-byte signed 9555 fractional number. The default format is "s.127". 9556 9557 `UQQmode' 9558 "Unsigned Quarter-Fractional" mode represents a single byte 9559 treated as an unsigned fractional number. The default format is 9560 ".8". 9561 9562 `UHQmode' 9563 "Unsigned Half-Fractional" mode represents a two-byte unsigned 9564 fractional number. The default format is ".16". 9565 9566 `USQmode' 9567 "Unsigned Single Fractional" mode represents a four-byte unsigned 9568 fractional number. The default format is ".32". 9569 9570 `UDQmode' 9571 "Unsigned Double Fractional" mode represents an eight-byte unsigned 9572 fractional number. The default format is ".64". 9573 9574 `UTQmode' 9575 "Unsigned Tetra Fractional" mode represents a sixteen-byte unsigned 9576 fractional number. The default format is ".128". 9577 9578 `HAmode' 9579 "Half-Accumulator" mode represents a two-byte signed accumulator. 9580 The default format is "s8.7". 9581 9582 `SAmode' 9583 "Single Accumulator" mode represents a four-byte signed 9584 accumulator. The default format is "s16.15". 9585 9586 `DAmode' 9587 "Double Accumulator" mode represents an eight-byte signed 9588 accumulator. The default format is "s32.31". 9589 9590 `TAmode' 9591 "Tetra Accumulator" mode represents a sixteen-byte signed 9592 accumulator. The default format is "s64.63". 9593 9594 `UHAmode' 9595 "Unsigned Half-Accumulator" mode represents a two-byte unsigned 9596 accumulator. The default format is "8.8". 9597 9598 `USAmode' 9599 "Unsigned Single Accumulator" mode represents a four-byte unsigned 9600 accumulator. The default format is "16.16". 9601 9602 `UDAmode' 9603 "Unsigned Double Accumulator" mode represents an eight-byte 9604 unsigned accumulator. The default format is "32.32". 9605 9606 `UTAmode' 9607 "Unsigned Tetra Accumulator" mode represents a sixteen-byte 9608 unsigned accumulator. The default format is "64.64". 9609 9610 `CCmode' 9611 "Condition Code" mode represents the value of a condition code, 9612 which is a machine-specific set of bits used to represent the 9613 result of a comparison operation. Other machine-specific modes 9614 may also be used for the condition code. These modes are not used 9615 on machines that use `cc0' (see *note Condition Code::). 9616 9617 `BLKmode' 9618 "Block" mode represents values that are aggregates to which none of 9619 the other modes apply. In RTL, only memory references can have 9620 this mode, and only if they appear in string-move or vector 9621 instructions. On machines which have no such instructions, 9622 `BLKmode' will not appear in RTL. 9623 9624 `VOIDmode' 9625 Void mode means the absence of a mode or an unspecified mode. For 9626 example, RTL expressions of code `const_int' have mode `VOIDmode' 9627 because they can be taken to have whatever mode the context 9628 requires. In debugging dumps of RTL, `VOIDmode' is expressed by 9629 the absence of any mode. 9630 9631 `QCmode, HCmode, SCmode, DCmode, XCmode, TCmode' 9632 These modes stand for a complex number represented as a pair of 9633 floating point values. The floating point values are in `QFmode', 9634 `HFmode', `SFmode', `DFmode', `XFmode', and `TFmode', respectively. 9635 9636 `CQImode, CHImode, CSImode, CDImode, CTImode, COImode' 9637 These modes stand for a complex number represented as a pair of 9638 integer values. The integer values are in `QImode', `HImode', 9639 `SImode', `DImode', `TImode', and `OImode', respectively. 9640 9641 The machine description defines `Pmode' as a C macro which expands 9642 into the machine mode used for addresses. Normally this is the mode 9643 whose size is `BITS_PER_WORD', `SImode' on 32-bit machines. 9644 9645 The only modes which a machine description must support are `QImode', 9646 and the modes corresponding to `BITS_PER_WORD', `FLOAT_TYPE_SIZE' and 9647 `DOUBLE_TYPE_SIZE'. The compiler will attempt to use `DImode' for 9648 8-byte structures and unions, but this can be prevented by overriding 9649 the definition of `MAX_FIXED_MODE_SIZE'. Alternatively, you can have 9650 the compiler use `TImode' for 16-byte structures and unions. Likewise, 9651 you can arrange for the C type `short int' to avoid using `HImode'. 9652 9653 Very few explicit references to machine modes remain in the compiler 9654 and these few references will soon be removed. Instead, the machine 9655 modes are divided into mode classes. These are represented by the 9656 enumeration type `enum mode_class' defined in `machmode.h'. The 9657 possible mode classes are: 9658 9659 `MODE_INT' 9660 Integer modes. By default these are `BImode', `QImode', `HImode', 9661 `SImode', `DImode', `TImode', and `OImode'. 9662 9663 `MODE_PARTIAL_INT' 9664 The "partial integer" modes, `PQImode', `PHImode', `PSImode' and 9665 `PDImode'. 9666 9667 `MODE_FLOAT' 9668 Floating point modes. By default these are `QFmode', `HFmode', 9669 `TQFmode', `SFmode', `DFmode', `XFmode' and `TFmode'. 9670 9671 `MODE_DECIMAL_FLOAT' 9672 Decimal floating point modes. By default these are `SDmode', 9673 `DDmode' and `TDmode'. 9674 9675 `MODE_FRACT' 9676 Signed fractional modes. By default these are `QQmode', `HQmode', 9677 `SQmode', `DQmode' and `TQmode'. 9678 9679 `MODE_UFRACT' 9680 Unsigned fractional modes. By default these are `UQQmode', 9681 `UHQmode', `USQmode', `UDQmode' and `UTQmode'. 9682 9683 `MODE_ACCUM' 9684 Signed accumulator modes. By default these are `HAmode', 9685 `SAmode', `DAmode' and `TAmode'. 9686 9687 `MODE_UACCUM' 9688 Unsigned accumulator modes. By default these are `UHAmode', 9689 `USAmode', `UDAmode' and `UTAmode'. 9690 9691 `MODE_COMPLEX_INT' 9692 Complex integer modes. (These are not currently implemented). 9693 9694 `MODE_COMPLEX_FLOAT' 9695 Complex floating point modes. By default these are `QCmode', 9696 `HCmode', `SCmode', `DCmode', `XCmode', and `TCmode'. 9697 9698 `MODE_FUNCTION' 9699 Algol or Pascal function variables including a static chain. 9700 (These are not currently implemented). 9701 9702 `MODE_CC' 9703 Modes representing condition code values. These are `CCmode' plus 9704 any `CC_MODE' modes listed in the `MACHINE-modes.def'. *Note Jump 9705 Patterns::, also see *Note Condition Code::. 9706 9707 `MODE_RANDOM' 9708 This is a catchall mode class for modes which don't fit into the 9709 above classes. Currently `VOIDmode' and `BLKmode' are in 9710 `MODE_RANDOM'. 9711 9712 Here are some C macros that relate to machine modes: 9713 9714 `GET_MODE (X)' 9715 Returns the machine mode of the RTX X. 9716 9717 `PUT_MODE (X, NEWMODE)' 9718 Alters the machine mode of the RTX X to be NEWMODE. 9719 9720 `NUM_MACHINE_MODES' 9721 Stands for the number of machine modes available on the target 9722 machine. This is one greater than the largest numeric value of any 9723 machine mode. 9724 9725 `GET_MODE_NAME (M)' 9726 Returns the name of mode M as a string. 9727 9728 `GET_MODE_CLASS (M)' 9729 Returns the mode class of mode M. 9730 9731 `GET_MODE_WIDER_MODE (M)' 9732 Returns the next wider natural mode. For example, the expression 9733 `GET_MODE_WIDER_MODE (QImode)' returns `HImode'. 9734 9735 `GET_MODE_SIZE (M)' 9736 Returns the size in bytes of a datum of mode M. 9737 9738 `GET_MODE_BITSIZE (M)' 9739 Returns the size in bits of a datum of mode M. 9740 9741 `GET_MODE_IBIT (M)' 9742 Returns the number of integral bits of a datum of fixed-point mode 9743 M. 9744 9745 `GET_MODE_FBIT (M)' 9746 Returns the number of fractional bits of a datum of fixed-point 9747 mode M. 9748 9749 `GET_MODE_MASK (M)' 9750 Returns a bitmask containing 1 for all bits in a word that fit 9751 within mode M. This macro can only be used for modes whose 9752 bitsize is less than or equal to `HOST_BITS_PER_INT'. 9753 9754 `GET_MODE_ALIGNMENT (M)' 9755 Return the required alignment, in bits, for an object of mode M. 9756 9757 `GET_MODE_UNIT_SIZE (M)' 9758 Returns the size in bytes of the subunits of a datum of mode M. 9759 This is the same as `GET_MODE_SIZE' except in the case of complex 9760 modes. For them, the unit size is the size of the real or 9761 imaginary part. 9762 9763 `GET_MODE_NUNITS (M)' 9764 Returns the number of units contained in a mode, i.e., 9765 `GET_MODE_SIZE' divided by `GET_MODE_UNIT_SIZE'. 9766 9767 `GET_CLASS_NARROWEST_MODE (C)' 9768 Returns the narrowest mode in mode class C. 9769 9770 The global variables `byte_mode' and `word_mode' contain modes whose 9771 classes are `MODE_INT' and whose bitsizes are either `BITS_PER_UNIT' or 9772 `BITS_PER_WORD', respectively. On 32-bit machines, these are `QImode' 9773 and `SImode', respectively. 9774 9775 9776 File: gccint.info, Node: Constants, Next: Regs and Memory, Prev: Machine Modes, Up: RTL 9777 9778 10.7 Constant Expression Types 9779 ============================== 9780 9781 The simplest RTL expressions are those that represent constant values. 9782 9783 `(const_int I)' 9784 This type of expression represents the integer value I. I is 9785 customarily accessed with the macro `INTVAL' as in `INTVAL (EXP)', 9786 which is equivalent to `XWINT (EXP, 0)'. 9787 9788 Constants generated for modes with fewer bits than `HOST_WIDE_INT' 9789 must be sign extended to full width (e.g., with `gen_int_mode'). 9790 9791 There is only one expression object for the integer value zero; it 9792 is the value of the variable `const0_rtx'. Likewise, the only 9793 expression for integer value one is found in `const1_rtx', the only 9794 expression for integer value two is found in `const2_rtx', and the 9795 only expression for integer value negative one is found in 9796 `constm1_rtx'. Any attempt to create an expression of code 9797 `const_int' and value zero, one, two or negative one will return 9798 `const0_rtx', `const1_rtx', `const2_rtx' or `constm1_rtx' as 9799 appropriate. 9800 9801 Similarly, there is only one object for the integer whose value is 9802 `STORE_FLAG_VALUE'. It is found in `const_true_rtx'. If 9803 `STORE_FLAG_VALUE' is one, `const_true_rtx' and `const1_rtx' will 9804 point to the same object. If `STORE_FLAG_VALUE' is -1, 9805 `const_true_rtx' and `constm1_rtx' will point to the same object. 9806 9807 `(const_double:M I0 I1 ...)' 9808 Represents either a floating-point constant of mode M or an 9809 integer constant too large to fit into `HOST_BITS_PER_WIDE_INT' 9810 bits but small enough to fit within twice that number of bits (GCC 9811 does not provide a mechanism to represent even larger constants). 9812 In the latter case, M will be `VOIDmode'. 9813 9814 If M is `VOIDmode', the bits of the value are stored in I0 and I1. 9815 I0 is customarily accessed with the macro `CONST_DOUBLE_LOW' and 9816 I1 with `CONST_DOUBLE_HIGH'. 9817 9818 If the constant is floating point (regardless of its precision), 9819 then the number of integers used to store the value depends on the 9820 size of `REAL_VALUE_TYPE' (*note Floating Point::). The integers 9821 represent a floating point number, but not precisely in the target 9822 machine's or host machine's floating point format. To convert 9823 them to the precise bit pattern used by the target machine, use 9824 the macro `REAL_VALUE_TO_TARGET_DOUBLE' and friends (*note Data 9825 Output::). 9826 9827 `(const_fixed:M ...)' 9828 Represents a fixed-point constant of mode M. The operand is a 9829 data structure of type `struct fixed_value' and is accessed with 9830 the macro `CONST_FIXED_VALUE'. The high part of data is accessed 9831 with `CONST_FIXED_VALUE_HIGH'; the low part is accessed with 9832 `CONST_FIXED_VALUE_LOW'. 9833 9834 `(const_vector:M [X0 X1 ...])' 9835 Represents a vector constant. The square brackets stand for the 9836 vector containing the constant elements. X0, X1 and so on are the 9837 `const_int', `const_double' or `const_fixed' elements. 9838 9839 The number of units in a `const_vector' is obtained with the macro 9840 `CONST_VECTOR_NUNITS' as in `CONST_VECTOR_NUNITS (V)'. 9841 9842 Individual elements in a vector constant are accessed with the 9843 macro `CONST_VECTOR_ELT' as in `CONST_VECTOR_ELT (V, N)' where V 9844 is the vector constant and N is the element desired. 9845 9846 `(const_string STR)' 9847 Represents a constant string with value STR. Currently this is 9848 used only for insn attributes (*note Insn Attributes::) since 9849 constant strings in C are placed in memory. 9850 9851 `(symbol_ref:MODE SYMBOL)' 9852 Represents the value of an assembler label for data. SYMBOL is a 9853 string that describes the name of the assembler label. If it 9854 starts with a `*', the label is the rest of SYMBOL not including 9855 the `*'. Otherwise, the label is SYMBOL, usually prefixed with 9856 `_'. 9857 9858 The `symbol_ref' contains a mode, which is usually `Pmode'. 9859 Usually that is the only mode for which a symbol is directly valid. 9860 9861 `(label_ref:MODE LABEL)' 9862 Represents the value of an assembler label for code. It contains 9863 one operand, an expression, which must be a `code_label' or a 9864 `note' of type `NOTE_INSN_DELETED_LABEL' that appears in the 9865 instruction sequence to identify the place where the label should 9866 go. 9867 9868 The reason for using a distinct expression type for code label 9869 references is so that jump optimization can distinguish them. 9870 9871 The `label_ref' contains a mode, which is usually `Pmode'. 9872 Usually that is the only mode for which a label is directly valid. 9873 9874 `(const:M EXP)' 9875 Represents a constant that is the result of an assembly-time 9876 arithmetic computation. The operand, EXP, is an expression that 9877 contains only constants (`const_int', `symbol_ref' and `label_ref' 9878 expressions) combined with `plus' and `minus'. However, not all 9879 combinations are valid, since the assembler cannot do arbitrary 9880 arithmetic on relocatable symbols. 9881 9882 M should be `Pmode'. 9883 9884 `(high:M EXP)' 9885 Represents the high-order bits of EXP, usually a `symbol_ref'. 9886 The number of bits is machine-dependent and is normally the number 9887 of bits specified in an instruction that initializes the high 9888 order bits of a register. It is used with `lo_sum' to represent 9889 the typical two-instruction sequence used in RISC machines to 9890 reference a global memory location. 9891 9892 M should be `Pmode'. 9893 9894 The macro `CONST0_RTX (MODE)' refers to an expression with value 0 in 9895 mode MODE. If mode MODE is of mode class `MODE_INT', it returns 9896 `const0_rtx'. If mode MODE is of mode class `MODE_FLOAT', it returns a 9897 `CONST_DOUBLE' expression in mode MODE. Otherwise, it returns a 9898 `CONST_VECTOR' expression in mode MODE. Similarly, the macro 9899 `CONST1_RTX (MODE)' refers to an expression with value 1 in mode MODE 9900 and similarly for `CONST2_RTX'. The `CONST1_RTX' and `CONST2_RTX' 9901 macros are undefined for vector modes. 9902 9903 9904 File: gccint.info, Node: Regs and Memory, Next: Arithmetic, Prev: Constants, Up: RTL 9905 9906 10.8 Registers and Memory 9907 ========================= 9908 9909 Here are the RTL expression types for describing access to machine 9910 registers and to main memory. 9911 9912 `(reg:M N)' 9913 For small values of the integer N (those that are less than 9914 `FIRST_PSEUDO_REGISTER'), this stands for a reference to machine 9915 register number N: a "hard register". For larger values of N, it 9916 stands for a temporary value or "pseudo register". The compiler's 9917 strategy is to generate code assuming an unlimited number of such 9918 pseudo registers, and later convert them into hard registers or 9919 into memory references. 9920 9921 M is the machine mode of the reference. It is necessary because 9922 machines can generally refer to each register in more than one 9923 mode. For example, a register may contain a full word but there 9924 may be instructions to refer to it as a half word or as a single 9925 byte, as well as instructions to refer to it as a floating point 9926 number of various precisions. 9927 9928 Even for a register that the machine can access in only one mode, 9929 the mode must always be specified. 9930 9931 The symbol `FIRST_PSEUDO_REGISTER' is defined by the machine 9932 description, since the number of hard registers on the machine is 9933 an invariant characteristic of the machine. Note, however, that 9934 not all of the machine registers must be general registers. All 9935 the machine registers that can be used for storage of data are 9936 given hard register numbers, even those that can be used only in 9937 certain instructions or can hold only certain types of data. 9938 9939 A hard register may be accessed in various modes throughout one 9940 function, but each pseudo register is given a natural mode and is 9941 accessed only in that mode. When it is necessary to describe an 9942 access to a pseudo register using a nonnatural mode, a `subreg' 9943 expression is used. 9944 9945 A `reg' expression with a machine mode that specifies more than 9946 one word of data may actually stand for several consecutive 9947 registers. If in addition the register number specifies a 9948 hardware register, then it actually represents several consecutive 9949 hardware registers starting with the specified one. 9950 9951 Each pseudo register number used in a function's RTL code is 9952 represented by a unique `reg' expression. 9953 9954 Some pseudo register numbers, those within the range of 9955 `FIRST_VIRTUAL_REGISTER' to `LAST_VIRTUAL_REGISTER' only appear 9956 during the RTL generation phase and are eliminated before the 9957 optimization phases. These represent locations in the stack frame 9958 that cannot be determined until RTL generation for the function 9959 has been completed. The following virtual register numbers are 9960 defined: 9961 9962 `VIRTUAL_INCOMING_ARGS_REGNUM' 9963 This points to the first word of the incoming arguments 9964 passed on the stack. Normally these arguments are placed 9965 there by the caller, but the callee may have pushed some 9966 arguments that were previously passed in registers. 9967 9968 When RTL generation is complete, this virtual register is 9969 replaced by the sum of the register given by 9970 `ARG_POINTER_REGNUM' and the value of `FIRST_PARM_OFFSET'. 9971 9972 `VIRTUAL_STACK_VARS_REGNUM' 9973 If `FRAME_GROWS_DOWNWARD' is defined to a nonzero value, this 9974 points to immediately above the first variable on the stack. 9975 Otherwise, it points to the first variable on the stack. 9976 9977 `VIRTUAL_STACK_VARS_REGNUM' is replaced with the sum of the 9978 register given by `FRAME_POINTER_REGNUM' and the value 9979 `STARTING_FRAME_OFFSET'. 9980 9981 `VIRTUAL_STACK_DYNAMIC_REGNUM' 9982 This points to the location of dynamically allocated memory 9983 on the stack immediately after the stack pointer has been 9984 adjusted by the amount of memory desired. 9985 9986 This virtual register is replaced by the sum of the register 9987 given by `STACK_POINTER_REGNUM' and the value 9988 `STACK_DYNAMIC_OFFSET'. 9989 9990 `VIRTUAL_OUTGOING_ARGS_REGNUM' 9991 This points to the location in the stack at which outgoing 9992 arguments should be written when the stack is pre-pushed 9993 (arguments pushed using push insns should always use 9994 `STACK_POINTER_REGNUM'). 9995 9996 This virtual register is replaced by the sum of the register 9997 given by `STACK_POINTER_REGNUM' and the value 9998 `STACK_POINTER_OFFSET'. 9999 10000 `(subreg:M1 REG:M2 BYTENUM)' 10001 `subreg' expressions are used to refer to a register in a machine 10002 mode other than its natural one, or to refer to one register of a 10003 multi-part `reg' that actually refers to several registers. 10004 10005 Each pseudo register has a natural mode. If it is necessary to 10006 operate on it in a different mode, the register must be enclosed 10007 in a `subreg'. 10008 10009 There are currently three supported types for the first operand of 10010 a `subreg': 10011 * pseudo registers This is the most common case. Most 10012 `subreg's have pseudo `reg's as their first operand. 10013 10014 * mem `subreg's of `mem' were common in earlier versions of GCC 10015 and are still supported. During the reload pass these are 10016 replaced by plain `mem's. On machines that do not do 10017 instruction scheduling, use of `subreg's of `mem' are still 10018 used, but this is no longer recommended. Such `subreg's are 10019 considered to be `register_operand's rather than 10020 `memory_operand's before and during reload. Because of this, 10021 the scheduling passes cannot properly schedule instructions 10022 with `subreg's of `mem', so for machines that do scheduling, 10023 `subreg's of `mem' should never be used. To support this, 10024 the combine and recog passes have explicit code to inhibit 10025 the creation of `subreg's of `mem' when `INSN_SCHEDULING' is 10026 defined. 10027 10028 The use of `subreg's of `mem' after the reload pass is an area 10029 that is not well understood and should be avoided. There is 10030 still some code in the compiler to support this, but this 10031 code has possibly rotted. This use of `subreg's is 10032 discouraged and will most likely not be supported in the 10033 future. 10034 10035 * hard registers It is seldom necessary to wrap hard registers 10036 in `subreg's; such registers would normally reduce to a 10037 single `reg' rtx. This use of `subreg's is discouraged and 10038 may not be supported in the future. 10039 10040 10041 `subreg's of `subreg's are not supported. Using 10042 `simplify_gen_subreg' is the recommended way to avoid this problem. 10043 10044 `subreg's come in two distinct flavors, each having its own usage 10045 and rules: 10046 10047 Paradoxical subregs 10048 When M1 is strictly wider than M2, the `subreg' expression is 10049 called "paradoxical". The canonical test for this class of 10050 `subreg' is: 10051 10052 GET_MODE_SIZE (M1) > GET_MODE_SIZE (M2) 10053 10054 Paradoxical `subreg's can be used as both lvalues and rvalues. 10055 When used as an lvalue, the low-order bits of the source value 10056 are stored in REG and the high-order bits are discarded. 10057 When used as an rvalue, the low-order bits of the `subreg' are 10058 taken from REG while the high-order bits may or may not be 10059 defined. 10060 10061 The high-order bits of rvalues are in the following 10062 circumstances: 10063 10064 * `subreg's of `mem' When M2 is smaller than a word, the 10065 macro `LOAD_EXTEND_OP', can control how the high-order 10066 bits are defined. 10067 10068 * `subreg' of `reg's The upper bits are defined when 10069 `SUBREG_PROMOTED_VAR_P' is true. 10070 `SUBREG_PROMOTED_UNSIGNED_P' describes what the upper 10071 bits hold. Such subregs usually represent local 10072 variables, register variables and parameter pseudo 10073 variables that have been promoted to a wider mode. 10074 10075 10076 BYTENUM is always zero for a paradoxical `subreg', even on 10077 big-endian targets. 10078 10079 For example, the paradoxical `subreg': 10080 10081 (set (subreg:SI (reg:HI X) 0) Y) 10082 10083 stores the lower 2 bytes of Y in X and discards the upper 2 10084 bytes. A subsequent: 10085 10086 (set Z (subreg:SI (reg:HI X) 0)) 10087 10088 would set the lower two bytes of Z to Y and set the upper two 10089 bytes to an unknown value assuming `SUBREG_PROMOTED_VAR_P' is 10090 false. 10091 10092 Normal subregs 10093 When M1 is at least as narrow as M2 the `subreg' expression 10094 is called "normal". 10095 10096 Normal `subreg's restrict consideration to certain bits of 10097 REG. There are two cases. If M1 is smaller than a word, the 10098 `subreg' refers to the least-significant part (or "lowpart") 10099 of one word of REG. If M1 is word-sized or greater, the 10100 `subreg' refers to one or more complete words. 10101 10102 When used as an lvalue, `subreg' is a word-based accessor. 10103 Storing to a `subreg' modifies all the words of REG that 10104 overlap the `subreg', but it leaves the other words of REG 10105 alone. 10106 10107 When storing to a normal `subreg' that is smaller than a word, 10108 the other bits of the referenced word are usually left in an 10109 undefined state. This laxity makes it easier to generate 10110 efficient code for such instructions. To represent an 10111 instruction that preserves all the bits outside of those in 10112 the `subreg', use `strict_low_part' or `zero_extract' around 10113 the `subreg'. 10114 10115 BYTENUM must identify the offset of the first byte of the 10116 `subreg' from the start of REG, assuming that REG is laid out 10117 in memory order. The memory order of bytes is defined by two 10118 target macros, `WORDS_BIG_ENDIAN' and `BYTES_BIG_ENDIAN': 10119 10120 * `WORDS_BIG_ENDIAN', if set to 1, says that byte number 10121 zero is part of the most significant word; otherwise, it 10122 is part of the least significant word. 10123 10124 * `BYTES_BIG_ENDIAN', if set to 1, says that byte number 10125 zero is the most significant byte within a word; 10126 otherwise, it is the least significant byte within a 10127 word. 10128 10129 On a few targets, `FLOAT_WORDS_BIG_ENDIAN' disagrees with 10130 `WORDS_BIG_ENDIAN'. However, most parts of the compiler treat 10131 floating point values as if they had the same endianness as 10132 integer values. This works because they handle them solely 10133 as a collection of integer values, with no particular 10134 numerical value. Only real.c and the runtime libraries care 10135 about `FLOAT_WORDS_BIG_ENDIAN'. 10136 10137 Thus, 10138 10139 (subreg:HI (reg:SI X) 2) 10140 10141 on a `BYTES_BIG_ENDIAN', `UNITS_PER_WORD == 4' target is the 10142 same as 10143 10144 (subreg:HI (reg:SI X) 0) 10145 10146 on a little-endian, `UNITS_PER_WORD == 4' target. Both 10147 `subreg's access the lower two bytes of register X. 10148 10149 10150 A `MODE_PARTIAL_INT' mode behaves as if it were as wide as the 10151 corresponding `MODE_INT' mode, except that it has an unknown 10152 number of undefined bits. For example: 10153 10154 (subreg:PSI (reg:SI 0) 0) 10155 10156 accesses the whole of `(reg:SI 0)', but the exact relationship 10157 between the `PSImode' value and the `SImode' value is not defined. 10158 If we assume `UNITS_PER_WORD <= 4', then the following two 10159 `subreg's: 10160 10161 (subreg:PSI (reg:DI 0) 0) 10162 (subreg:PSI (reg:DI 0) 4) 10163 10164 represent independent 4-byte accesses to the two halves of 10165 `(reg:DI 0)'. Both `subreg's have an unknown number of undefined 10166 bits. 10167 10168 If `UNITS_PER_WORD <= 2' then these two `subreg's: 10169 10170 (subreg:HI (reg:PSI 0) 0) 10171 (subreg:HI (reg:PSI 0) 2) 10172 10173 represent independent 2-byte accesses that together span the whole 10174 of `(reg:PSI 0)'. Storing to the first `subreg' does not affect 10175 the value of the second, and vice versa. `(reg:PSI 0)' has an 10176 unknown number of undefined bits, so the assignment: 10177 10178 (set (subreg:HI (reg:PSI 0) 0) (reg:HI 4)) 10179 10180 does not guarantee that `(subreg:HI (reg:PSI 0) 0)' has the value 10181 `(reg:HI 4)'. 10182 10183 The rules above apply to both pseudo REGs and hard REGs. If the 10184 semantics are not correct for particular combinations of M1, M2 10185 and hard REG, the target-specific code must ensure that those 10186 combinations are never used. For example: 10187 10188 CANNOT_CHANGE_MODE_CLASS (M2, M1, CLASS) 10189 10190 must be true for every class CLASS that includes REG. 10191 10192 The first operand of a `subreg' expression is customarily accessed 10193 with the `SUBREG_REG' macro and the second operand is customarily 10194 accessed with the `SUBREG_BYTE' macro. 10195 10196 It has been several years since a platform in which 10197 `BYTES_BIG_ENDIAN' not equal to `WORDS_BIG_ENDIAN' has been 10198 tested. Anyone wishing to support such a platform in the future 10199 may be confronted with code rot. 10200 10201 `(scratch:M)' 10202 This represents a scratch register that will be required for the 10203 execution of a single instruction and not used subsequently. It is 10204 converted into a `reg' by either the local register allocator or 10205 the reload pass. 10206 10207 `scratch' is usually present inside a `clobber' operation (*note 10208 Side Effects::). 10209 10210 `(cc0)' 10211 This refers to the machine's condition code register. It has no 10212 operands and may not have a machine mode. There are two ways to 10213 use it: 10214 10215 * To stand for a complete set of condition code flags. This is 10216 best on most machines, where each comparison sets the entire 10217 series of flags. 10218 10219 With this technique, `(cc0)' may be validly used in only two 10220 contexts: as the destination of an assignment (in test and 10221 compare instructions) and in comparison operators comparing 10222 against zero (`const_int' with value zero; that is to say, 10223 `const0_rtx'). 10224 10225 * To stand for a single flag that is the result of a single 10226 condition. This is useful on machines that have only a 10227 single flag bit, and in which comparison instructions must 10228 specify the condition to test. 10229 10230 With this technique, `(cc0)' may be validly used in only two 10231 contexts: as the destination of an assignment (in test and 10232 compare instructions) where the source is a comparison 10233 operator, and as the first operand of `if_then_else' (in a 10234 conditional branch). 10235 10236 There is only one expression object of code `cc0'; it is the value 10237 of the variable `cc0_rtx'. Any attempt to create an expression of 10238 code `cc0' will return `cc0_rtx'. 10239 10240 Instructions can set the condition code implicitly. On many 10241 machines, nearly all instructions set the condition code based on 10242 the value that they compute or store. It is not necessary to 10243 record these actions explicitly in the RTL because the machine 10244 description includes a prescription for recognizing the 10245 instructions that do so (by means of the macro 10246 `NOTICE_UPDATE_CC'). *Note Condition Code::. Only instructions 10247 whose sole purpose is to set the condition code, and instructions 10248 that use the condition code, need mention `(cc0)'. 10249 10250 On some machines, the condition code register is given a register 10251 number and a `reg' is used instead of `(cc0)'. This is usually the 10252 preferable approach if only a small subset of instructions modify 10253 the condition code. Other machines store condition codes in 10254 general registers; in such cases a pseudo register should be used. 10255 10256 Some machines, such as the SPARC and RS/6000, have two sets of 10257 arithmetic instructions, one that sets and one that does not set 10258 the condition code. This is best handled by normally generating 10259 the instruction that does not set the condition code, and making a 10260 pattern that both performs the arithmetic and sets the condition 10261 code register (which would not be `(cc0)' in this case). For 10262 examples, search for `addcc' and `andcc' in `sparc.md'. 10263 10264 `(pc)' 10265 This represents the machine's program counter. It has no operands 10266 and may not have a machine mode. `(pc)' may be validly used only 10267 in certain specific contexts in jump instructions. 10268 10269 There is only one expression object of code `pc'; it is the value 10270 of the variable `pc_rtx'. Any attempt to create an expression of 10271 code `pc' will return `pc_rtx'. 10272 10273 All instructions that do not jump alter the program counter 10274 implicitly by incrementing it, but there is no need to mention 10275 this in the RTL. 10276 10277 `(mem:M ADDR ALIAS)' 10278 This RTX represents a reference to main memory at an address 10279 represented by the expression ADDR. M specifies how large a unit 10280 of memory is accessed. ALIAS specifies an alias set for the 10281 reference. In general two items are in different alias sets if 10282 they cannot reference the same memory address. 10283 10284 The construct `(mem:BLK (scratch))' is considered to alias all 10285 other memories. Thus it may be used as a memory barrier in 10286 epilogue stack deallocation patterns. 10287 10288 `(concatM RTX RTX)' 10289 This RTX represents the concatenation of two other RTXs. This is 10290 used for complex values. It should only appear in the RTL 10291 attached to declarations and during RTL generation. It should not 10292 appear in the ordinary insn chain. 10293 10294 `(concatnM [RTX ...])' 10295 This RTX represents the concatenation of all the RTX to make a 10296 single value. Like `concat', this should only appear in 10297 declarations, and not in the insn chain. 10298 10299 10300 File: gccint.info, Node: Arithmetic, Next: Comparisons, Prev: Regs and Memory, Up: RTL 10301 10302 10.9 RTL Expressions for Arithmetic 10303 =================================== 10304 10305 Unless otherwise specified, all the operands of arithmetic expressions 10306 must be valid for mode M. An operand is valid for mode M if it has 10307 mode M, or if it is a `const_int' or `const_double' and M is a mode of 10308 class `MODE_INT'. 10309 10310 For commutative binary operations, constants should be placed in the 10311 second operand. 10312 10313 `(plus:M X Y)' 10314 `(ss_plus:M X Y)' 10315 `(us_plus:M X Y)' 10316 These three expressions all represent the sum of the values 10317 represented by X and Y carried out in machine mode M. They differ 10318 in their behavior on overflow of integer modes. `plus' wraps 10319 round modulo the width of M; `ss_plus' saturates at the maximum 10320 signed value representable in M; `us_plus' saturates at the 10321 maximum unsigned value. 10322 10323 `(lo_sum:M X Y)' 10324 This expression represents the sum of X and the low-order bits of 10325 Y. It is used with `high' (*note Constants::) to represent the 10326 typical two-instruction sequence used in RISC machines to 10327 reference a global memory location. 10328 10329 The number of low order bits is machine-dependent but is normally 10330 the number of bits in a `Pmode' item minus the number of bits set 10331 by `high'. 10332 10333 M should be `Pmode'. 10334 10335 `(minus:M X Y)' 10336 `(ss_minus:M X Y)' 10337 `(us_minus:M X Y)' 10338 These three expressions represent the result of subtracting Y from 10339 X, carried out in mode M. Behavior on overflow is the same as for 10340 the three variants of `plus' (see above). 10341 10342 `(compare:M X Y)' 10343 Represents the result of subtracting Y from X for purposes of 10344 comparison. The result is computed without overflow, as if with 10345 infinite precision. 10346 10347 Of course, machines can't really subtract with infinite precision. 10348 However, they can pretend to do so when only the sign of the 10349 result will be used, which is the case when the result is stored 10350 in the condition code. And that is the _only_ way this kind of 10351 expression may validly be used: as a value to be stored in the 10352 condition codes, either `(cc0)' or a register. *Note 10353 Comparisons::. 10354 10355 The mode M is not related to the modes of X and Y, but instead is 10356 the mode of the condition code value. If `(cc0)' is used, it is 10357 `VOIDmode'. Otherwise it is some mode in class `MODE_CC', often 10358 `CCmode'. *Note Condition Code::. If M is `VOIDmode' or 10359 `CCmode', the operation returns sufficient information (in an 10360 unspecified format) so that any comparison operator can be applied 10361 to the result of the `COMPARE' operation. For other modes in 10362 class `MODE_CC', the operation only returns a subset of this 10363 information. 10364 10365 Normally, X and Y must have the same mode. Otherwise, `compare' 10366 is valid only if the mode of X is in class `MODE_INT' and Y is a 10367 `const_int' or `const_double' with mode `VOIDmode'. The mode of X 10368 determines what mode the comparison is to be done in; thus it must 10369 not be `VOIDmode'. 10370 10371 If one of the operands is a constant, it should be placed in the 10372 second operand and the comparison code adjusted as appropriate. 10373 10374 A `compare' specifying two `VOIDmode' constants is not valid since 10375 there is no way to know in what mode the comparison is to be 10376 performed; the comparison must either be folded during the 10377 compilation or the first operand must be loaded into a register 10378 while its mode is still known. 10379 10380 `(neg:M X)' 10381 `(ss_neg:M X)' 10382 `(us_neg:M X)' 10383 These two expressions represent the negation (subtraction from 10384 zero) of the value represented by X, carried out in mode M. They 10385 differ in the behavior on overflow of integer modes. In the case 10386 of `neg', the negation of the operand may be a number not 10387 representable in mode M, in which case it is truncated to M. 10388 `ss_neg' and `us_neg' ensure that an out-of-bounds result 10389 saturates to the maximum or minimum signed or unsigned value. 10390 10391 `(mult:M X Y)' 10392 `(ss_mult:M X Y)' 10393 `(us_mult:M X Y)' 10394 Represents the signed product of the values represented by X and Y 10395 carried out in machine mode M. `ss_mult' and `us_mult' ensure 10396 that an out-of-bounds result saturates to the maximum or minimum 10397 signed or unsigned value. 10398 10399 Some machines support a multiplication that generates a product 10400 wider than the operands. Write the pattern for this as 10401 10402 (mult:M (sign_extend:M X) (sign_extend:M Y)) 10403 10404 where M is wider than the modes of X and Y, which need not be the 10405 same. 10406 10407 For unsigned widening multiplication, use the same idiom, but with 10408 `zero_extend' instead of `sign_extend'. 10409 10410 `(div:M X Y)' 10411 `(ss_div:M X Y)' 10412 Represents the quotient in signed division of X by Y, carried out 10413 in machine mode M. If M is a floating point mode, it represents 10414 the exact quotient; otherwise, the integerized quotient. `ss_div' 10415 ensures that an out-of-bounds result saturates to the maximum or 10416 minimum signed value. 10417 10418 Some machines have division instructions in which the operands and 10419 quotient widths are not all the same; you should represent such 10420 instructions using `truncate' and `sign_extend' as in, 10421 10422 (truncate:M1 (div:M2 X (sign_extend:M2 Y))) 10423 10424 `(udiv:M X Y)' 10425 `(us_div:M X Y)' 10426 Like `div' but represents unsigned division. `us_div' ensures 10427 that an out-of-bounds result saturates to the maximum or minimum 10428 unsigned value. 10429 10430 `(mod:M X Y)' 10431 `(umod:M X Y)' 10432 Like `div' and `udiv' but represent the remainder instead of the 10433 quotient. 10434 10435 `(smin:M X Y)' 10436 `(smax:M X Y)' 10437 Represents the smaller (for `smin') or larger (for `smax') of X 10438 and Y, interpreted as signed values in mode M. When used with 10439 floating point, if both operands are zeros, or if either operand 10440 is `NaN', then it is unspecified which of the two operands is 10441 returned as the result. 10442 10443 `(umin:M X Y)' 10444 `(umax:M X Y)' 10445 Like `smin' and `smax', but the values are interpreted as unsigned 10446 integers. 10447 10448 `(not:M X)' 10449 Represents the bitwise complement of the value represented by X, 10450 carried out in mode M, which must be a fixed-point machine mode. 10451 10452 `(and:M X Y)' 10453 Represents the bitwise logical-and of the values represented by X 10454 and Y, carried out in machine mode M, which must be a fixed-point 10455 machine mode. 10456 10457 `(ior:M X Y)' 10458 Represents the bitwise inclusive-or of the values represented by X 10459 and Y, carried out in machine mode M, which must be a fixed-point 10460 mode. 10461 10462 `(xor:M X Y)' 10463 Represents the bitwise exclusive-or of the values represented by X 10464 and Y, carried out in machine mode M, which must be a fixed-point 10465 mode. 10466 10467 `(ashift:M X C)' 10468 `(ss_ashift:M X C)' 10469 `(us_ashift:M X C)' 10470 These three expressions represent the result of arithmetically 10471 shifting X left by C places. They differ in their behavior on 10472 overflow of integer modes. An `ashift' operation is a plain shift 10473 with no special behavior in case of a change in the sign bit; 10474 `ss_ashift' and `us_ashift' saturates to the minimum or maximum 10475 representable value if any of the bits shifted out differs from 10476 the final sign bit. 10477 10478 X have mode M, a fixed-point machine mode. C be a fixed-point 10479 mode or be a constant with mode `VOIDmode'; which mode is 10480 determined by the mode called for in the machine description entry 10481 for the left-shift instruction. For example, on the VAX, the mode 10482 of C is `QImode' regardless of M. 10483 10484 `(lshiftrt:M X C)' 10485 `(ashiftrt:M X C)' 10486 Like `ashift' but for right shift. Unlike the case for left shift, 10487 these two operations are distinct. 10488 10489 `(rotate:M X C)' 10490 `(rotatert:M X C)' 10491 Similar but represent left and right rotate. If C is a constant, 10492 use `rotate'. 10493 10494 `(abs:M X)' 10495 Represents the absolute value of X, computed in mode M. 10496 10497 `(sqrt:M X)' 10498 Represents the square root of X, computed in mode M. Most often M 10499 will be a floating point mode. 10500 10501 `(ffs:M X)' 10502 Represents one plus the index of the least significant 1-bit in X, 10503 represented as an integer of mode M. (The value is zero if X is 10504 zero.) The mode of X need not be M; depending on the target 10505 machine, various mode combinations may be valid. 10506 10507 `(clz:M X)' 10508 Represents the number of leading 0-bits in X, represented as an 10509 integer of mode M, starting at the most significant bit position. 10510 If X is zero, the value is determined by 10511 `CLZ_DEFINED_VALUE_AT_ZERO' (*note Misc::). Note that this is one 10512 of the few expressions that is not invariant under widening. The 10513 mode of X will usually be an integer mode. 10514 10515 `(ctz:M X)' 10516 Represents the number of trailing 0-bits in X, represented as an 10517 integer of mode M, starting at the least significant bit position. 10518 If X is zero, the value is determined by 10519 `CTZ_DEFINED_VALUE_AT_ZERO' (*note Misc::). Except for this case, 10520 `ctz(x)' is equivalent to `ffs(X) - 1'. The mode of X will 10521 usually be an integer mode. 10522 10523 `(popcount:M X)' 10524 Represents the number of 1-bits in X, represented as an integer of 10525 mode M. The mode of X will usually be an integer mode. 10526 10527 `(parity:M X)' 10528 Represents the number of 1-bits modulo 2 in X, represented as an 10529 integer of mode M. The mode of X will usually be an integer mode. 10530 10531 `(bswap:M X)' 10532 Represents the value X with the order of bytes reversed, carried 10533 out in mode M, which must be a fixed-point machine mode. 10534 10535 10536 File: gccint.info, Node: Comparisons, Next: Bit-Fields, Prev: Arithmetic, Up: RTL 10537 10538 10.10 Comparison Operations 10539 =========================== 10540 10541 Comparison operators test a relation on two operands and are considered 10542 to represent a machine-dependent nonzero value described by, but not 10543 necessarily equal to, `STORE_FLAG_VALUE' (*note Misc::) if the relation 10544 holds, or zero if it does not, for comparison operators whose results 10545 have a `MODE_INT' mode, `FLOAT_STORE_FLAG_VALUE' (*note Misc::) if the 10546 relation holds, or zero if it does not, for comparison operators that 10547 return floating-point values, and a vector of either 10548 `VECTOR_STORE_FLAG_VALUE' (*note Misc::) if the relation holds, or of 10549 zeros if it does not, for comparison operators that return vector 10550 results. The mode of the comparison operation is independent of the 10551 mode of the data being compared. If the comparison operation is being 10552 tested (e.g., the first operand of an `if_then_else'), the mode must be 10553 `VOIDmode'. 10554 10555 There are two ways that comparison operations may be used. The 10556 comparison operators may be used to compare the condition codes `(cc0)' 10557 against zero, as in `(eq (cc0) (const_int 0))'. Such a construct 10558 actually refers to the result of the preceding instruction in which the 10559 condition codes were set. The instruction setting the condition code 10560 must be adjacent to the instruction using the condition code; only 10561 `note' insns may separate them. 10562 10563 Alternatively, a comparison operation may directly compare two data 10564 objects. The mode of the comparison is determined by the operands; they 10565 must both be valid for a common machine mode. A comparison with both 10566 operands constant would be invalid as the machine mode could not be 10567 deduced from it, but such a comparison should never exist in RTL due to 10568 constant folding. 10569 10570 In the example above, if `(cc0)' were last set to `(compare X Y)', the 10571 comparison operation is identical to `(eq X Y)'. Usually only one style 10572 of comparisons is supported on a particular machine, but the combine 10573 pass will try to merge the operations to produce the `eq' shown in case 10574 it exists in the context of the particular insn involved. 10575 10576 Inequality comparisons come in two flavors, signed and unsigned. Thus, 10577 there are distinct expression codes `gt' and `gtu' for signed and 10578 unsigned greater-than. These can produce different results for the same 10579 pair of integer values: for example, 1 is signed greater-than -1 but not 10580 unsigned greater-than, because -1 when regarded as unsigned is actually 10581 `0xffffffff' which is greater than 1. 10582 10583 The signed comparisons are also used for floating point values. 10584 Floating point comparisons are distinguished by the machine modes of 10585 the operands. 10586 10587 `(eq:M X Y)' 10588 `STORE_FLAG_VALUE' if the values represented by X and Y are equal, 10589 otherwise 0. 10590 10591 `(ne:M X Y)' 10592 `STORE_FLAG_VALUE' if the values represented by X and Y are not 10593 equal, otherwise 0. 10594 10595 `(gt:M X Y)' 10596 `STORE_FLAG_VALUE' if the X is greater than Y. If they are 10597 fixed-point, the comparison is done in a signed sense. 10598 10599 `(gtu:M X Y)' 10600 Like `gt' but does unsigned comparison, on fixed-point numbers 10601 only. 10602 10603 `(lt:M X Y)' 10604 `(ltu:M X Y)' 10605 Like `gt' and `gtu' but test for "less than". 10606 10607 `(ge:M X Y)' 10608 `(geu:M X Y)' 10609 Like `gt' and `gtu' but test for "greater than or equal". 10610 10611 `(le:M X Y)' 10612 `(leu:M X Y)' 10613 Like `gt' and `gtu' but test for "less than or equal". 10614 10615 `(if_then_else COND THEN ELSE)' 10616 This is not a comparison operation but is listed here because it is 10617 always used in conjunction with a comparison operation. To be 10618 precise, COND is a comparison expression. This expression 10619 represents a choice, according to COND, between the value 10620 represented by THEN and the one represented by ELSE. 10621 10622 On most machines, `if_then_else' expressions are valid only to 10623 express conditional jumps. 10624 10625 `(cond [TEST1 VALUE1 TEST2 VALUE2 ...] DEFAULT)' 10626 Similar to `if_then_else', but more general. Each of TEST1, 10627 TEST2, ... is performed in turn. The result of this expression is 10628 the VALUE corresponding to the first nonzero test, or DEFAULT if 10629 none of the tests are nonzero expressions. 10630 10631 This is currently not valid for instruction patterns and is 10632 supported only for insn attributes. *Note Insn Attributes::. 10633 10634 10635 File: gccint.info, Node: Bit-Fields, Next: Vector Operations, Prev: Comparisons, Up: RTL 10636 10637 10.11 Bit-Fields 10638 ================ 10639 10640 Special expression codes exist to represent bit-field instructions. 10641 10642 `(sign_extract:M LOC SIZE POS)' 10643 This represents a reference to a sign-extended bit-field contained 10644 or starting in LOC (a memory or register reference). The bit-field 10645 is SIZE bits wide and starts at bit POS. The compilation option 10646 `BITS_BIG_ENDIAN' says which end of the memory unit POS counts 10647 from. 10648 10649 If LOC is in memory, its mode must be a single-byte integer mode. 10650 If LOC is in a register, the mode to use is specified by the 10651 operand of the `insv' or `extv' pattern (*note Standard Names::) 10652 and is usually a full-word integer mode, which is the default if 10653 none is specified. 10654 10655 The mode of POS is machine-specific and is also specified in the 10656 `insv' or `extv' pattern. 10657 10658 The mode M is the same as the mode that would be used for LOC if 10659 it were a register. 10660 10661 A `sign_extract' can not appear as an lvalue, or part thereof, in 10662 RTL. 10663 10664 `(zero_extract:M LOC SIZE POS)' 10665 Like `sign_extract' but refers to an unsigned or zero-extended 10666 bit-field. The same sequence of bits are extracted, but they are 10667 filled to an entire word with zeros instead of by sign-extension. 10668 10669 Unlike `sign_extract', this type of expressions can be lvalues in 10670 RTL; they may appear on the left side of an assignment, indicating 10671 insertion of a value into the specified bit-field. 10672 10673 10674 File: gccint.info, Node: Vector Operations, Next: Conversions, Prev: Bit-Fields, Up: RTL 10675 10676 10.12 Vector Operations 10677 ======================= 10678 10679 All normal RTL expressions can be used with vector modes; they are 10680 interpreted as operating on each part of the vector independently. 10681 Additionally, there are a few new expressions to describe specific 10682 vector operations. 10683 10684 `(vec_merge:M VEC1 VEC2 ITEMS)' 10685 This describes a merge operation between two vectors. The result 10686 is a vector of mode M; its elements are selected from either VEC1 10687 or VEC2. Which elements are selected is described by ITEMS, which 10688 is a bit mask represented by a `const_int'; a zero bit indicates 10689 the corresponding element in the result vector is taken from VEC2 10690 while a set bit indicates it is taken from VEC1. 10691 10692 `(vec_select:M VEC1 SELECTION)' 10693 This describes an operation that selects parts of a vector. VEC1 10694 is the source vector, SELECTION is a `parallel' that contains a 10695 `const_int' for each of the subparts of the result vector, giving 10696 the number of the source subpart that should be stored into it. 10697 10698 `(vec_concat:M VEC1 VEC2)' 10699 Describes a vector concat operation. The result is a 10700 concatenation of the vectors VEC1 and VEC2; its length is the sum 10701 of the lengths of the two inputs. 10702 10703 `(vec_duplicate:M VEC)' 10704 This operation converts a small vector into a larger one by 10705 duplicating the input values. The output vector mode must have 10706 the same submodes as the input vector mode, and the number of 10707 output parts must be an integer multiple of the number of input 10708 parts. 10709 10710 10711 10712 File: gccint.info, Node: Conversions, Next: RTL Declarations, Prev: Vector Operations, Up: RTL 10713 10714 10.13 Conversions 10715 ================= 10716 10717 All conversions between machine modes must be represented by explicit 10718 conversion operations. For example, an expression which is the sum of 10719 a byte and a full word cannot be written as `(plus:SI (reg:QI 34) 10720 (reg:SI 80))' because the `plus' operation requires two operands of the 10721 same machine mode. Therefore, the byte-sized operand is enclosed in a 10722 conversion operation, as in 10723 10724 (plus:SI (sign_extend:SI (reg:QI 34)) (reg:SI 80)) 10725 10726 The conversion operation is not a mere placeholder, because there may 10727 be more than one way of converting from a given starting mode to the 10728 desired final mode. The conversion operation code says how to do it. 10729 10730 For all conversion operations, X must not be `VOIDmode' because the 10731 mode in which to do the conversion would not be known. The conversion 10732 must either be done at compile-time or X must be placed into a register. 10733 10734 `(sign_extend:M X)' 10735 Represents the result of sign-extending the value X to machine 10736 mode M. M must be a fixed-point mode and X a fixed-point value of 10737 a mode narrower than M. 10738 10739 `(zero_extend:M X)' 10740 Represents the result of zero-extending the value X to machine 10741 mode M. M must be a fixed-point mode and X a fixed-point value of 10742 a mode narrower than M. 10743 10744 `(float_extend:M X)' 10745 Represents the result of extending the value X to machine mode M. 10746 M must be a floating point mode and X a floating point value of a 10747 mode narrower than M. 10748 10749 `(truncate:M X)' 10750 Represents the result of truncating the value X to machine mode M. 10751 M must be a fixed-point mode and X a fixed-point value of a mode 10752 wider than M. 10753 10754 `(ss_truncate:M X)' 10755 Represents the result of truncating the value X to machine mode M, 10756 using signed saturation in the case of overflow. Both M and the 10757 mode of X must be fixed-point modes. 10758 10759 `(us_truncate:M X)' 10760 Represents the result of truncating the value X to machine mode M, 10761 using unsigned saturation in the case of overflow. Both M and the 10762 mode of X must be fixed-point modes. 10763 10764 `(float_truncate:M X)' 10765 Represents the result of truncating the value X to machine mode M. 10766 M must be a floating point mode and X a floating point value of a 10767 mode wider than M. 10768 10769 `(float:M X)' 10770 Represents the result of converting fixed point value X, regarded 10771 as signed, to floating point mode M. 10772 10773 `(unsigned_float:M X)' 10774 Represents the result of converting fixed point value X, regarded 10775 as unsigned, to floating point mode M. 10776 10777 `(fix:M X)' 10778 When M is a floating-point mode, represents the result of 10779 converting floating point value X (valid for mode M) to an 10780 integer, still represented in floating point mode M, by rounding 10781 towards zero. 10782 10783 When M is a fixed-point mode, represents the result of converting 10784 floating point value X to mode M, regarded as signed. How 10785 rounding is done is not specified, so this operation may be used 10786 validly in compiling C code only for integer-valued operands. 10787 10788 `(unsigned_fix:M X)' 10789 Represents the result of converting floating point value X to 10790 fixed point mode M, regarded as unsigned. How rounding is done is 10791 not specified. 10792 10793 `(fract_convert:M X)' 10794 Represents the result of converting fixed-point value X to 10795 fixed-point mode M, signed integer value X to fixed-point mode M, 10796 floating-point value X to fixed-point mode M, fixed-point value X 10797 to integer mode M regarded as signed, or fixed-point value X to 10798 floating-point mode M. When overflows or underflows happen, the 10799 results are undefined. 10800 10801 `(sat_fract:M X)' 10802 Represents the result of converting fixed-point value X to 10803 fixed-point mode M, signed integer value X to fixed-point mode M, 10804 or floating-point value X to fixed-point mode M. When overflows 10805 or underflows happen, the results are saturated to the maximum or 10806 the minimum. 10807 10808 `(unsigned_fract_convert:M X)' 10809 Represents the result of converting fixed-point value X to integer 10810 mode M regarded as unsigned, or unsigned integer value X to 10811 fixed-point mode M. When overflows or underflows happen, the 10812 results are undefined. 10813 10814 `(unsigned_sat_fract:M X)' 10815 Represents the result of converting unsigned integer value X to 10816 fixed-point mode M. When overflows or underflows happen, the 10817 results are saturated to the maximum or the minimum. 10818 10819 10820 File: gccint.info, Node: RTL Declarations, Next: Side Effects, Prev: Conversions, Up: RTL 10821 10822 10.14 Declarations 10823 ================== 10824 10825 Declaration expression codes do not represent arithmetic operations but 10826 rather state assertions about their operands. 10827 10828 `(strict_low_part (subreg:M (reg:N R) 0))' 10829 This expression code is used in only one context: as the 10830 destination operand of a `set' expression. In addition, the 10831 operand of this expression must be a non-paradoxical `subreg' 10832 expression. 10833 10834 The presence of `strict_low_part' says that the part of the 10835 register which is meaningful in mode N, but is not part of mode M, 10836 is not to be altered. Normally, an assignment to such a subreg is 10837 allowed to have undefined effects on the rest of the register when 10838 M is less than a word. 10839 10840 10841 File: gccint.info, Node: Side Effects, Next: Incdec, Prev: RTL Declarations, Up: RTL 10842 10843 10.15 Side Effect Expressions 10844 ============================= 10845 10846 The expression codes described so far represent values, not actions. 10847 But machine instructions never produce values; they are meaningful only 10848 for their side effects on the state of the machine. Special expression 10849 codes are used to represent side effects. 10850 10851 The body of an instruction is always one of these side effect codes; 10852 the codes described above, which represent values, appear only as the 10853 operands of these. 10854 10855 `(set LVAL X)' 10856 Represents the action of storing the value of X into the place 10857 represented by LVAL. LVAL must be an expression representing a 10858 place that can be stored in: `reg' (or `subreg', `strict_low_part' 10859 or `zero_extract'), `mem', `pc', `parallel', or `cc0'. 10860 10861 If LVAL is a `reg', `subreg' or `mem', it has a machine mode; then 10862 X must be valid for that mode. 10863 10864 If LVAL is a `reg' whose machine mode is less than the full width 10865 of the register, then it means that the part of the register 10866 specified by the machine mode is given the specified value and the 10867 rest of the register receives an undefined value. Likewise, if 10868 LVAL is a `subreg' whose machine mode is narrower than the mode of 10869 the register, the rest of the register can be changed in an 10870 undefined way. 10871 10872 If LVAL is a `strict_low_part' of a subreg, then the part of the 10873 register specified by the machine mode of the `subreg' is given 10874 the value X and the rest of the register is not changed. 10875 10876 If LVAL is a `zero_extract', then the referenced part of the 10877 bit-field (a memory or register reference) specified by the 10878 `zero_extract' is given the value X and the rest of the bit-field 10879 is not changed. Note that `sign_extract' can not appear in LVAL. 10880 10881 If LVAL is `(cc0)', it has no machine mode, and X may be either a 10882 `compare' expression or a value that may have any mode. The 10883 latter case represents a "test" instruction. The expression `(set 10884 (cc0) (reg:M N))' is equivalent to `(set (cc0) (compare (reg:M N) 10885 (const_int 0)))'. Use the former expression to save space during 10886 the compilation. 10887 10888 If LVAL is a `parallel', it is used to represent the case of a 10889 function returning a structure in multiple registers. Each element 10890 of the `parallel' is an `expr_list' whose first operand is a `reg' 10891 and whose second operand is a `const_int' representing the offset 10892 (in bytes) into the structure at which the data in that register 10893 corresponds. The first element may be null to indicate that the 10894 structure is also passed partly in memory. 10895 10896 If LVAL is `(pc)', we have a jump instruction, and the 10897 possibilities for X are very limited. It may be a `label_ref' 10898 expression (unconditional jump). It may be an `if_then_else' 10899 (conditional jump), in which case either the second or the third 10900 operand must be `(pc)' (for the case which does not jump) and the 10901 other of the two must be a `label_ref' (for the case which does 10902 jump). X may also be a `mem' or `(plus:SI (pc) Y)', where Y may 10903 be a `reg' or a `mem'; these unusual patterns are used to 10904 represent jumps through branch tables. 10905 10906 If LVAL is neither `(cc0)' nor `(pc)', the mode of LVAL must not 10907 be `VOIDmode' and the mode of X must be valid for the mode of LVAL. 10908 10909 LVAL is customarily accessed with the `SET_DEST' macro and X with 10910 the `SET_SRC' macro. 10911 10912 `(return)' 10913 As the sole expression in a pattern, represents a return from the 10914 current function, on machines where this can be done with one 10915 instruction, such as VAXen. On machines where a multi-instruction 10916 "epilogue" must be executed in order to return from the function, 10917 returning is done by jumping to a label which precedes the 10918 epilogue, and the `return' expression code is never used. 10919 10920 Inside an `if_then_else' expression, represents the value to be 10921 placed in `pc' to return to the caller. 10922 10923 Note that an insn pattern of `(return)' is logically equivalent to 10924 `(set (pc) (return))', but the latter form is never used. 10925 10926 `(call FUNCTION NARGS)' 10927 Represents a function call. FUNCTION is a `mem' expression whose 10928 address is the address of the function to be called. NARGS is an 10929 expression which can be used for two purposes: on some machines it 10930 represents the number of bytes of stack argument; on others, it 10931 represents the number of argument registers. 10932 10933 Each machine has a standard machine mode which FUNCTION must have. 10934 The machine description defines macro `FUNCTION_MODE' to expand 10935 into the requisite mode name. The purpose of this mode is to 10936 specify what kind of addressing is allowed, on machines where the 10937 allowed kinds of addressing depend on the machine mode being 10938 addressed. 10939 10940 `(clobber X)' 10941 Represents the storing or possible storing of an unpredictable, 10942 undescribed value into X, which must be a `reg', `scratch', 10943 `parallel' or `mem' expression. 10944 10945 One place this is used is in string instructions that store 10946 standard values into particular hard registers. It may not be 10947 worth the trouble to describe the values that are stored, but it 10948 is essential to inform the compiler that the registers will be 10949 altered, lest it attempt to keep data in them across the string 10950 instruction. 10951 10952 If X is `(mem:BLK (const_int 0))' or `(mem:BLK (scratch))', it 10953 means that all memory locations must be presumed clobbered. If X 10954 is a `parallel', it has the same meaning as a `parallel' in a 10955 `set' expression. 10956 10957 Note that the machine description classifies certain hard 10958 registers as "call-clobbered". All function call instructions are 10959 assumed by default to clobber these registers, so there is no need 10960 to use `clobber' expressions to indicate this fact. Also, each 10961 function call is assumed to have the potential to alter any memory 10962 location, unless the function is declared `const'. 10963 10964 If the last group of expressions in a `parallel' are each a 10965 `clobber' expression whose arguments are `reg' or `match_scratch' 10966 (*note RTL Template::) expressions, the combiner phase can add the 10967 appropriate `clobber' expressions to an insn it has constructed 10968 when doing so will cause a pattern to be matched. 10969 10970 This feature can be used, for example, on a machine that whose 10971 multiply and add instructions don't use an MQ register but which 10972 has an add-accumulate instruction that does clobber the MQ 10973 register. Similarly, a combined instruction might require a 10974 temporary register while the constituent instructions might not. 10975 10976 When a `clobber' expression for a register appears inside a 10977 `parallel' with other side effects, the register allocator 10978 guarantees that the register is unoccupied both before and after 10979 that insn if it is a hard register clobber. For pseudo-register 10980 clobber, the register allocator and the reload pass do not assign 10981 the same hard register to the clobber and the input operands if 10982 there is an insn alternative containing the `&' constraint (*note 10983 Modifiers::) for the clobber and the hard register is in register 10984 classes of the clobber in the alternative. You can clobber either 10985 a specific hard register, a pseudo register, or a `scratch' 10986 expression; in the latter two cases, GCC will allocate a hard 10987 register that is available there for use as a temporary. 10988 10989 For instructions that require a temporary register, you should use 10990 `scratch' instead of a pseudo-register because this will allow the 10991 combiner phase to add the `clobber' when required. You do this by 10992 coding (`clobber' (`match_scratch' ...)). If you do clobber a 10993 pseudo register, use one which appears nowhere else--generate a 10994 new one each time. Otherwise, you may confuse CSE. 10995 10996 There is one other known use for clobbering a pseudo register in a 10997 `parallel': when one of the input operands of the insn is also 10998 clobbered by the insn. In this case, using the same pseudo 10999 register in the clobber and elsewhere in the insn produces the 11000 expected results. 11001 11002 `(use X)' 11003 Represents the use of the value of X. It indicates that the value 11004 in X at this point in the program is needed, even though it may 11005 not be apparent why this is so. Therefore, the compiler will not 11006 attempt to delete previous instructions whose only effect is to 11007 store a value in X. X must be a `reg' expression. 11008 11009 In some situations, it may be tempting to add a `use' of a 11010 register in a `parallel' to describe a situation where the value 11011 of a special register will modify the behavior of the instruction. 11012 An hypothetical example might be a pattern for an addition that can 11013 either wrap around or use saturating addition depending on the 11014 value of a special control register: 11015 11016 (parallel [(set (reg:SI 2) (unspec:SI [(reg:SI 3) 11017 (reg:SI 4)] 0)) 11018 (use (reg:SI 1))]) 11019 11020 This will not work, several of the optimizers only look at 11021 expressions locally; it is very likely that if you have multiple 11022 insns with identical inputs to the `unspec', they will be 11023 optimized away even if register 1 changes in between. 11024 11025 This means that `use' can _only_ be used to describe that the 11026 register is live. You should think twice before adding `use' 11027 statements, more often you will want to use `unspec' instead. The 11028 `use' RTX is most commonly useful to describe that a fixed 11029 register is implicitly used in an insn. It is also safe to use in 11030 patterns where the compiler knows for other reasons that the result 11031 of the whole pattern is variable, such as `movmemM' or `call' 11032 patterns. 11033 11034 During the reload phase, an insn that has a `use' as pattern can 11035 carry a reg_equal note. These `use' insns will be deleted before 11036 the reload phase exits. 11037 11038 During the delayed branch scheduling phase, X may be an insn. 11039 This indicates that X previously was located at this place in the 11040 code and its data dependencies need to be taken into account. 11041 These `use' insns will be deleted before the delayed branch 11042 scheduling phase exits. 11043 11044 `(parallel [X0 X1 ...])' 11045 Represents several side effects performed in parallel. The square 11046 brackets stand for a vector; the operand of `parallel' is a vector 11047 of expressions. X0, X1 and so on are individual side effect 11048 expressions--expressions of code `set', `call', `return', 11049 `clobber' or `use'. 11050 11051 "In parallel" means that first all the values used in the 11052 individual side-effects are computed, and second all the actual 11053 side-effects are performed. For example, 11054 11055 (parallel [(set (reg:SI 1) (mem:SI (reg:SI 1))) 11056 (set (mem:SI (reg:SI 1)) (reg:SI 1))]) 11057 11058 says unambiguously that the values of hard register 1 and the 11059 memory location addressed by it are interchanged. In both places 11060 where `(reg:SI 1)' appears as a memory address it refers to the 11061 value in register 1 _before_ the execution of the insn. 11062 11063 It follows that it is _incorrect_ to use `parallel' and expect the 11064 result of one `set' to be available for the next one. For 11065 example, people sometimes attempt to represent a jump-if-zero 11066 instruction this way: 11067 11068 (parallel [(set (cc0) (reg:SI 34)) 11069 (set (pc) (if_then_else 11070 (eq (cc0) (const_int 0)) 11071 (label_ref ...) 11072 (pc)))]) 11073 11074 But this is incorrect, because it says that the jump condition 11075 depends on the condition code value _before_ this instruction, not 11076 on the new value that is set by this instruction. 11077 11078 Peephole optimization, which takes place together with final 11079 assembly code output, can produce insns whose patterns consist of 11080 a `parallel' whose elements are the operands needed to output the 11081 resulting assembler code--often `reg', `mem' or constant 11082 expressions. This would not be well-formed RTL at any other stage 11083 in compilation, but it is ok then because no further optimization 11084 remains to be done. However, the definition of the macro 11085 `NOTICE_UPDATE_CC', if any, must deal with such insns if you 11086 define any peephole optimizations. 11087 11088 `(cond_exec [COND EXPR])' 11089 Represents a conditionally executed expression. The EXPR is 11090 executed only if the COND is nonzero. The COND expression must 11091 not have side-effects, but the EXPR may very well have 11092 side-effects. 11093 11094 `(sequence [INSNS ...])' 11095 Represents a sequence of insns. Each of the INSNS that appears in 11096 the vector is suitable for appearing in the chain of insns, so it 11097 must be an `insn', `jump_insn', `call_insn', `code_label', 11098 `barrier' or `note'. 11099 11100 A `sequence' RTX is never placed in an actual insn during RTL 11101 generation. It represents the sequence of insns that result from a 11102 `define_expand' _before_ those insns are passed to `emit_insn' to 11103 insert them in the chain of insns. When actually inserted, the 11104 individual sub-insns are separated out and the `sequence' is 11105 forgotten. 11106 11107 After delay-slot scheduling is completed, an insn and all the 11108 insns that reside in its delay slots are grouped together into a 11109 `sequence'. The insn requiring the delay slot is the first insn 11110 in the vector; subsequent insns are to be placed in the delay slot. 11111 11112 `INSN_ANNULLED_BRANCH_P' is set on an insn in a delay slot to 11113 indicate that a branch insn should be used that will conditionally 11114 annul the effect of the insns in the delay slots. In such a case, 11115 `INSN_FROM_TARGET_P' indicates that the insn is from the target of 11116 the branch and should be executed only if the branch is taken; 11117 otherwise the insn should be executed only if the branch is not 11118 taken. *Note Delay Slots::. 11119 11120 These expression codes appear in place of a side effect, as the body of 11121 an insn, though strictly speaking they do not always describe side 11122 effects as such: 11123 11124 `(asm_input S)' 11125 Represents literal assembler code as described by the string S. 11126 11127 `(unspec [OPERANDS ...] INDEX)' 11128 `(unspec_volatile [OPERANDS ...] INDEX)' 11129 Represents a machine-specific operation on OPERANDS. INDEX 11130 selects between multiple machine-specific operations. 11131 `unspec_volatile' is used for volatile operations and operations 11132 that may trap; `unspec' is used for other operations. 11133 11134 These codes may appear inside a `pattern' of an insn, inside a 11135 `parallel', or inside an expression. 11136 11137 `(addr_vec:M [LR0 LR1 ...])' 11138 Represents a table of jump addresses. The vector elements LR0, 11139 etc., are `label_ref' expressions. The mode M specifies how much 11140 space is given to each address; normally M would be `Pmode'. 11141 11142 `(addr_diff_vec:M BASE [LR0 LR1 ...] MIN MAX FLAGS)' 11143 Represents a table of jump addresses expressed as offsets from 11144 BASE. The vector elements LR0, etc., are `label_ref' expressions 11145 and so is BASE. The mode M specifies how much space is given to 11146 each address-difference. MIN and MAX are set up by branch 11147 shortening and hold a label with a minimum and a maximum address, 11148 respectively. FLAGS indicates the relative position of BASE, MIN 11149 and MAX to the containing insn and of MIN and MAX to BASE. See 11150 rtl.def for details. 11151 11152 `(prefetch:M ADDR RW LOCALITY)' 11153 Represents prefetch of memory at address ADDR. Operand RW is 1 if 11154 the prefetch is for data to be written, 0 otherwise; targets that 11155 do not support write prefetches should treat this as a normal 11156 prefetch. Operand LOCALITY specifies the amount of temporal 11157 locality; 0 if there is none or 1, 2, or 3 for increasing levels 11158 of temporal locality; targets that do not support locality hints 11159 should ignore this. 11160 11161 This insn is used to minimize cache-miss latency by moving data 11162 into a cache before it is accessed. It should use only 11163 non-faulting data prefetch instructions. 11164 11165 11166 File: gccint.info, Node: Incdec, Next: Assembler, Prev: Side Effects, Up: RTL 11167 11168 10.16 Embedded Side-Effects on Addresses 11169 ======================================== 11170 11171 Six special side-effect expression codes appear as memory addresses. 11172 11173 `(pre_dec:M X)' 11174 Represents the side effect of decrementing X by a standard amount 11175 and represents also the value that X has after being decremented. 11176 X must be a `reg' or `mem', but most machines allow only a `reg'. 11177 M must be the machine mode for pointers on the machine in use. 11178 The amount X is decremented by is the length in bytes of the 11179 machine mode of the containing memory reference of which this 11180 expression serves as the address. Here is an example of its use: 11181 11182 (mem:DF (pre_dec:SI (reg:SI 39))) 11183 11184 This says to decrement pseudo register 39 by the length of a 11185 `DFmode' value and use the result to address a `DFmode' value. 11186 11187 `(pre_inc:M X)' 11188 Similar, but specifies incrementing X instead of decrementing it. 11189 11190 `(post_dec:M X)' 11191 Represents the same side effect as `pre_dec' but a different 11192 value. The value represented here is the value X has before being 11193 decremented. 11194 11195 `(post_inc:M X)' 11196 Similar, but specifies incrementing X instead of decrementing it. 11197 11198 `(post_modify:M X Y)' 11199 Represents the side effect of setting X to Y and represents X 11200 before X is modified. X must be a `reg' or `mem', but most 11201 machines allow only a `reg'. M must be the machine mode for 11202 pointers on the machine in use. 11203 11204 The expression Y must be one of three forms: `(plus:M X Z)', 11205 `(minus:M X Z)', or `(plus:M X I)', where Z is an index register 11206 and I is a constant. 11207 11208 Here is an example of its use: 11209 11210 (mem:SF (post_modify:SI (reg:SI 42) (plus (reg:SI 42) 11211 (reg:SI 48)))) 11212 11213 This says to modify pseudo register 42 by adding the contents of 11214 pseudo register 48 to it, after the use of what ever 42 points to. 11215 11216 `(pre_modify:M X EXPR)' 11217 Similar except side effects happen before the use. 11218 11219 These embedded side effect expressions must be used with care. 11220 Instruction patterns may not use them. Until the `flow' pass of the 11221 compiler, they may occur only to represent pushes onto the stack. The 11222 `flow' pass finds cases where registers are incremented or decremented 11223 in one instruction and used as an address shortly before or after; 11224 these cases are then transformed to use pre- or post-increment or 11225 -decrement. 11226 11227 If a register used as the operand of these expressions is used in 11228 another address in an insn, the original value of the register is used. 11229 Uses of the register outside of an address are not permitted within the 11230 same insn as a use in an embedded side effect expression because such 11231 insns behave differently on different machines and hence must be treated 11232 as ambiguous and disallowed. 11233 11234 An instruction that can be represented with an embedded side effect 11235 could also be represented using `parallel' containing an additional 11236 `set' to describe how the address register is altered. This is not 11237 done because machines that allow these operations at all typically 11238 allow them wherever a memory address is called for. Describing them as 11239 additional parallel stores would require doubling the number of entries 11240 in the machine description. 11241 11242 11243 File: gccint.info, Node: Assembler, Next: Insns, Prev: Incdec, Up: RTL 11244 11245 10.17 Assembler Instructions as Expressions 11246 =========================================== 11247 11248 The RTX code `asm_operands' represents a value produced by a 11249 user-specified assembler instruction. It is used to represent an `asm' 11250 statement with arguments. An `asm' statement with a single output 11251 operand, like this: 11252 11253 asm ("foo %1,%2,%0" : "=a" (outputvar) : "g" (x + y), "di" (*z)); 11254 11255 is represented using a single `asm_operands' RTX which represents the 11256 value that is stored in `outputvar': 11257 11258 (set RTX-FOR-OUTPUTVAR 11259 (asm_operands "foo %1,%2,%0" "a" 0 11260 [RTX-FOR-ADDITION-RESULT RTX-FOR-*Z] 11261 [(asm_input:M1 "g") 11262 (asm_input:M2 "di")])) 11263 11264 Here the operands of the `asm_operands' RTX are the assembler template 11265 string, the output-operand's constraint, the index-number of the output 11266 operand among the output operands specified, a vector of input operand 11267 RTX's, and a vector of input-operand modes and constraints. The mode 11268 M1 is the mode of the sum `x+y'; M2 is that of `*z'. 11269 11270 When an `asm' statement has multiple output values, its insn has 11271 several such `set' RTX's inside of a `parallel'. Each `set' contains a 11272 `asm_operands'; all of these share the same assembler template and 11273 vectors, but each contains the constraint for the respective output 11274 operand. They are also distinguished by the output-operand index 11275 number, which is 0, 1, ... for successive output operands. 11276 11277 11278 File: gccint.info, Node: Insns, Next: Calls, Prev: Assembler, Up: RTL 11279 11280 10.18 Insns 11281 =========== 11282 11283 The RTL representation of the code for a function is a doubly-linked 11284 chain of objects called "insns". Insns are expressions with special 11285 codes that are used for no other purpose. Some insns are actual 11286 instructions; others represent dispatch tables for `switch' statements; 11287 others represent labels to jump to or various sorts of declarative 11288 information. 11289 11290 In addition to its own specific data, each insn must have a unique 11291 id-number that distinguishes it from all other insns in the current 11292 function (after delayed branch scheduling, copies of an insn with the 11293 same id-number may be present in multiple places in a function, but 11294 these copies will always be identical and will only appear inside a 11295 `sequence'), and chain pointers to the preceding and following insns. 11296 These three fields occupy the same position in every insn, independent 11297 of the expression code of the insn. They could be accessed with `XEXP' 11298 and `XINT', but instead three special macros are always used: 11299 11300 `INSN_UID (I)' 11301 Accesses the unique id of insn I. 11302 11303 `PREV_INSN (I)' 11304 Accesses the chain pointer to the insn preceding I. If I is the 11305 first insn, this is a null pointer. 11306 11307 `NEXT_INSN (I)' 11308 Accesses the chain pointer to the insn following I. If I is the 11309 last insn, this is a null pointer. 11310 11311 The first insn in the chain is obtained by calling `get_insns'; the 11312 last insn is the result of calling `get_last_insn'. Within the chain 11313 delimited by these insns, the `NEXT_INSN' and `PREV_INSN' pointers must 11314 always correspond: if INSN is not the first insn, 11315 11316 NEXT_INSN (PREV_INSN (INSN)) == INSN 11317 11318 is always true and if INSN is not the last insn, 11319 11320 PREV_INSN (NEXT_INSN (INSN)) == INSN 11321 11322 is always true. 11323 11324 After delay slot scheduling, some of the insns in the chain might be 11325 `sequence' expressions, which contain a vector of insns. The value of 11326 `NEXT_INSN' in all but the last of these insns is the next insn in the 11327 vector; the value of `NEXT_INSN' of the last insn in the vector is the 11328 same as the value of `NEXT_INSN' for the `sequence' in which it is 11329 contained. Similar rules apply for `PREV_INSN'. 11330 11331 This means that the above invariants are not necessarily true for insns 11332 inside `sequence' expressions. Specifically, if INSN is the first insn 11333 in a `sequence', `NEXT_INSN (PREV_INSN (INSN))' is the insn containing 11334 the `sequence' expression, as is the value of `PREV_INSN (NEXT_INSN 11335 (INSN))' if INSN is the last insn in the `sequence' expression. You 11336 can use these expressions to find the containing `sequence' expression. 11337 11338 Every insn has one of the following six expression codes: 11339 11340 `insn' 11341 The expression code `insn' is used for instructions that do not 11342 jump and do not do function calls. `sequence' expressions are 11343 always contained in insns with code `insn' even if one of those 11344 insns should jump or do function calls. 11345 11346 Insns with code `insn' have four additional fields beyond the three 11347 mandatory ones listed above. These four are described in a table 11348 below. 11349 11350 `jump_insn' 11351 The expression code `jump_insn' is used for instructions that may 11352 jump (or, more generally, may contain `label_ref' expressions to 11353 which `pc' can be set in that instruction). If there is an 11354 instruction to return from the current function, it is recorded as 11355 a `jump_insn'. 11356 11357 `jump_insn' insns have the same extra fields as `insn' insns, 11358 accessed in the same way and in addition contain a field 11359 `JUMP_LABEL' which is defined once jump optimization has completed. 11360 11361 For simple conditional and unconditional jumps, this field contains 11362 the `code_label' to which this insn will (possibly conditionally) 11363 branch. In a more complex jump, `JUMP_LABEL' records one of the 11364 labels that the insn refers to; other jump target labels are 11365 recorded as `REG_LABEL_TARGET' notes. The exception is `addr_vec' 11366 and `addr_diff_vec', where `JUMP_LABEL' is `NULL_RTX' and the only 11367 way to find the labels is to scan the entire body of the insn. 11368 11369 Return insns count as jumps, but since they do not refer to any 11370 labels, their `JUMP_LABEL' is `NULL_RTX'. 11371 11372 `call_insn' 11373 The expression code `call_insn' is used for instructions that may 11374 do function calls. It is important to distinguish these 11375 instructions because they imply that certain registers and memory 11376 locations may be altered unpredictably. 11377 11378 `call_insn' insns have the same extra fields as `insn' insns, 11379 accessed in the same way and in addition contain a field 11380 `CALL_INSN_FUNCTION_USAGE', which contains a list (chain of 11381 `expr_list' expressions) containing `use' and `clobber' 11382 expressions that denote hard registers and `MEM's used or 11383 clobbered by the called function. 11384 11385 A `MEM' generally points to a stack slots in which arguments passed 11386 to the libcall by reference (*note TARGET_PASS_BY_REFERENCE: 11387 Register Arguments.) are stored. If the argument is caller-copied 11388 (*note TARGET_CALLEE_COPIES: Register Arguments.), the stack slot 11389 will be mentioned in `CLOBBER' and `USE' entries; if it's 11390 callee-copied, only a `USE' will appear, and the `MEM' may point 11391 to addresses that are not stack slots. 11392 11393 `CLOBBER'ed registers in this list augment registers specified in 11394 `CALL_USED_REGISTERS' (*note Register Basics::). 11395 11396 `code_label' 11397 A `code_label' insn represents a label that a jump insn can jump 11398 to. It contains two special fields of data in addition to the 11399 three standard ones. `CODE_LABEL_NUMBER' is used to hold the 11400 "label number", a number that identifies this label uniquely among 11401 all the labels in the compilation (not just in the current 11402 function). Ultimately, the label is represented in the assembler 11403 output as an assembler label, usually of the form `LN' where N is 11404 the label number. 11405 11406 When a `code_label' appears in an RTL expression, it normally 11407 appears within a `label_ref' which represents the address of the 11408 label, as a number. 11409 11410 Besides as a `code_label', a label can also be represented as a 11411 `note' of type `NOTE_INSN_DELETED_LABEL'. 11412 11413 The field `LABEL_NUSES' is only defined once the jump optimization 11414 phase is completed. It contains the number of times this label is 11415 referenced in the current function. 11416 11417 The field `LABEL_KIND' differentiates four different types of 11418 labels: `LABEL_NORMAL', `LABEL_STATIC_ENTRY', 11419 `LABEL_GLOBAL_ENTRY', and `LABEL_WEAK_ENTRY'. The only labels 11420 that do not have type `LABEL_NORMAL' are "alternate entry points" 11421 to the current function. These may be static (visible only in the 11422 containing translation unit), global (exposed to all translation 11423 units), or weak (global, but can be overridden by another symbol 11424 with the same name). 11425 11426 Much of the compiler treats all four kinds of label identically. 11427 Some of it needs to know whether or not a label is an alternate 11428 entry point; for this purpose, the macro `LABEL_ALT_ENTRY_P' is 11429 provided. It is equivalent to testing whether `LABEL_KIND (label) 11430 == LABEL_NORMAL'. The only place that cares about the distinction 11431 between static, global, and weak alternate entry points, besides 11432 the front-end code that creates them, is the function 11433 `output_alternate_entry_point', in `final.c'. 11434 11435 To set the kind of a label, use the `SET_LABEL_KIND' macro. 11436 11437 `barrier' 11438 Barriers are placed in the instruction stream when control cannot 11439 flow past them. They are placed after unconditional jump 11440 instructions to indicate that the jumps are unconditional and 11441 after calls to `volatile' functions, which do not return (e.g., 11442 `exit'). They contain no information beyond the three standard 11443 fields. 11444 11445 `note' 11446 `note' insns are used to represent additional debugging and 11447 declarative information. They contain two nonstandard fields, an 11448 integer which is accessed with the macro `NOTE_LINE_NUMBER' and a 11449 string accessed with `NOTE_SOURCE_FILE'. 11450 11451 If `NOTE_LINE_NUMBER' is positive, the note represents the 11452 position of a source line and `NOTE_SOURCE_FILE' is the source 11453 file name that the line came from. These notes control generation 11454 of line number data in the assembler output. 11455 11456 Otherwise, `NOTE_LINE_NUMBER' is not really a line number but a 11457 code with one of the following values (and `NOTE_SOURCE_FILE' must 11458 contain a null pointer): 11459 11460 `NOTE_INSN_DELETED' 11461 Such a note is completely ignorable. Some passes of the 11462 compiler delete insns by altering them into notes of this 11463 kind. 11464 11465 `NOTE_INSN_DELETED_LABEL' 11466 This marks what used to be a `code_label', but was not used 11467 for other purposes than taking its address and was 11468 transformed to mark that no code jumps to it. 11469 11470 `NOTE_INSN_BLOCK_BEG' 11471 `NOTE_INSN_BLOCK_END' 11472 These types of notes indicate the position of the beginning 11473 and end of a level of scoping of variable names. They 11474 control the output of debugging information. 11475 11476 `NOTE_INSN_EH_REGION_BEG' 11477 `NOTE_INSN_EH_REGION_END' 11478 These types of notes indicate the position of the beginning 11479 and end of a level of scoping for exception handling. 11480 `NOTE_BLOCK_NUMBER' identifies which `CODE_LABEL' or `note' 11481 of type `NOTE_INSN_DELETED_LABEL' is associated with the 11482 given region. 11483 11484 `NOTE_INSN_LOOP_BEG' 11485 `NOTE_INSN_LOOP_END' 11486 These types of notes indicate the position of the beginning 11487 and end of a `while' or `for' loop. They enable the loop 11488 optimizer to find loops quickly. 11489 11490 `NOTE_INSN_LOOP_CONT' 11491 Appears at the place in a loop that `continue' statements 11492 jump to. 11493 11494 `NOTE_INSN_LOOP_VTOP' 11495 This note indicates the place in a loop where the exit test 11496 begins for those loops in which the exit test has been 11497 duplicated. This position becomes another virtual start of 11498 the loop when considering loop invariants. 11499 11500 `NOTE_INSN_FUNCTION_BEG' 11501 Appears at the start of the function body, after the function 11502 prologue. 11503 11504 11505 These codes are printed symbolically when they appear in debugging 11506 dumps. 11507 11508 The machine mode of an insn is normally `VOIDmode', but some phases 11509 use the mode for various purposes. 11510 11511 The common subexpression elimination pass sets the mode of an insn to 11512 `QImode' when it is the first insn in a block that has already been 11513 processed. 11514 11515 The second Haifa scheduling pass, for targets that can multiple issue, 11516 sets the mode of an insn to `TImode' when it is believed that the 11517 instruction begins an issue group. That is, when the instruction 11518 cannot issue simultaneously with the previous. This may be relied on 11519 by later passes, in particular machine-dependent reorg. 11520 11521 Here is a table of the extra fields of `insn', `jump_insn' and 11522 `call_insn' insns: 11523 11524 `PATTERN (I)' 11525 An expression for the side effect performed by this insn. This 11526 must be one of the following codes: `set', `call', `use', 11527 `clobber', `return', `asm_input', `asm_output', `addr_vec', 11528 `addr_diff_vec', `trap_if', `unspec', `unspec_volatile', 11529 `parallel', `cond_exec', or `sequence'. If it is a `parallel', 11530 each element of the `parallel' must be one these codes, except that 11531 `parallel' expressions cannot be nested and `addr_vec' and 11532 `addr_diff_vec' are not permitted inside a `parallel' expression. 11533 11534 `INSN_CODE (I)' 11535 An integer that says which pattern in the machine description 11536 matches this insn, or -1 if the matching has not yet been 11537 attempted. 11538 11539 Such matching is never attempted and this field remains -1 on an 11540 insn whose pattern consists of a single `use', `clobber', 11541 `asm_input', `addr_vec' or `addr_diff_vec' expression. 11542 11543 Matching is also never attempted on insns that result from an `asm' 11544 statement. These contain at least one `asm_operands' expression. 11545 The function `asm_noperands' returns a non-negative value for such 11546 insns. 11547 11548 In the debugging output, this field is printed as a number 11549 followed by a symbolic representation that locates the pattern in 11550 the `md' file as some small positive or negative offset from a 11551 named pattern. 11552 11553 `LOG_LINKS (I)' 11554 A list (chain of `insn_list' expressions) giving information about 11555 dependencies between instructions within a basic block. Neither a 11556 jump nor a label may come between the related insns. These are 11557 only used by the schedulers and by combine. This is a deprecated 11558 data structure. Def-use and use-def chains are now preferred. 11559 11560 `REG_NOTES (I)' 11561 A list (chain of `expr_list' and `insn_list' expressions) giving 11562 miscellaneous information about the insn. It is often information 11563 pertaining to the registers used in this insn. 11564 11565 The `LOG_LINKS' field of an insn is a chain of `insn_list' 11566 expressions. Each of these has two operands: the first is an insn, and 11567 the second is another `insn_list' expression (the next one in the 11568 chain). The last `insn_list' in the chain has a null pointer as second 11569 operand. The significant thing about the chain is which insns appear 11570 in it (as first operands of `insn_list' expressions). Their order is 11571 not significant. 11572 11573 This list is originally set up by the flow analysis pass; it is a null 11574 pointer until then. Flow only adds links for those data dependencies 11575 which can be used for instruction combination. For each insn, the flow 11576 analysis pass adds a link to insns which store into registers values 11577 that are used for the first time in this insn. 11578 11579 The `REG_NOTES' field of an insn is a chain similar to the `LOG_LINKS' 11580 field but it includes `expr_list' expressions in addition to 11581 `insn_list' expressions. There are several kinds of register notes, 11582 which are distinguished by the machine mode, which in a register note 11583 is really understood as being an `enum reg_note'. The first operand OP 11584 of the note is data whose meaning depends on the kind of note. 11585 11586 The macro `REG_NOTE_KIND (X)' returns the kind of register note. Its 11587 counterpart, the macro `PUT_REG_NOTE_KIND (X, NEWKIND)' sets the 11588 register note type of X to be NEWKIND. 11589 11590 Register notes are of three classes: They may say something about an 11591 input to an insn, they may say something about an output of an insn, or 11592 they may create a linkage between two insns. There are also a set of 11593 values that are only used in `LOG_LINKS'. 11594 11595 These register notes annotate inputs to an insn: 11596 11597 `REG_DEAD' 11598 The value in OP dies in this insn; that is to say, altering the 11599 value immediately after this insn would not affect the future 11600 behavior of the program. 11601 11602 It does not follow that the register OP has no useful value after 11603 this insn since OP is not necessarily modified by this insn. 11604 Rather, no subsequent instruction uses the contents of OP. 11605 11606 `REG_UNUSED' 11607 The register OP being set by this insn will not be used in a 11608 subsequent insn. This differs from a `REG_DEAD' note, which 11609 indicates that the value in an input will not be used subsequently. 11610 These two notes are independent; both may be present for the same 11611 register. 11612 11613 `REG_INC' 11614 The register OP is incremented (or decremented; at this level 11615 there is no distinction) by an embedded side effect inside this 11616 insn. This means it appears in a `post_inc', `pre_inc', 11617 `post_dec' or `pre_dec' expression. 11618 11619 `REG_NONNEG' 11620 The register OP is known to have a nonnegative value when this 11621 insn is reached. This is used so that decrement and branch until 11622 zero instructions, such as the m68k dbra, can be matched. 11623 11624 The `REG_NONNEG' note is added to insns only if the machine 11625 description has a `decrement_and_branch_until_zero' pattern. 11626 11627 `REG_LABEL_OPERAND' 11628 This insn uses OP, a `code_label' or a `note' of type 11629 `NOTE_INSN_DELETED_LABEL', but is not a `jump_insn', or it is a 11630 `jump_insn' that refers to the operand as an ordinary operand. 11631 The label may still eventually be a jump target, but if so in an 11632 indirect jump in a subsequent insn. The presence of this note 11633 allows jump optimization to be aware that OP is, in fact, being 11634 used, and flow optimization to build an accurate flow graph. 11635 11636 `REG_LABEL_TARGET' 11637 This insn is a `jump_insn' but not a `addr_vec' or 11638 `addr_diff_vec'. It uses OP, a `code_label' as a direct or 11639 indirect jump target. Its purpose is similar to that of 11640 `REG_LABEL_OPERAND'. This note is only present if the insn has 11641 multiple targets; the last label in the insn (in the highest 11642 numbered insn-field) goes into the `JUMP_LABEL' field and does not 11643 have a `REG_LABEL_TARGET' note. *Note JUMP_LABEL: Insns. 11644 11645 `REG_CROSSING_JUMP' 11646 This insn is an branching instruction (either an unconditional 11647 jump or an indirect jump) which crosses between hot and cold 11648 sections, which could potentially be very far apart in the 11649 executable. The presence of this note indicates to other 11650 optimizations that this branching instruction should not be 11651 "collapsed" into a simpler branching construct. It is used when 11652 the optimization to partition basic blocks into hot and cold 11653 sections is turned on. 11654 11655 `REG_SETJMP' 11656 Appears attached to each `CALL_INSN' to `setjmp' or a related 11657 function. 11658 11659 The following notes describe attributes of outputs of an insn: 11660 11661 `REG_EQUIV' 11662 `REG_EQUAL' 11663 This note is only valid on an insn that sets only one register and 11664 indicates that that register will be equal to OP at run time; the 11665 scope of this equivalence differs between the two types of notes. 11666 The value which the insn explicitly copies into the register may 11667 look different from OP, but they will be equal at run time. If the 11668 output of the single `set' is a `strict_low_part' expression, the 11669 note refers to the register that is contained in `SUBREG_REG' of 11670 the `subreg' expression. 11671 11672 For `REG_EQUIV', the register is equivalent to OP throughout the 11673 entire function, and could validly be replaced in all its 11674 occurrences by OP. ("Validly" here refers to the data flow of the 11675 program; simple replacement may make some insns invalid.) For 11676 example, when a constant is loaded into a register that is never 11677 assigned any other value, this kind of note is used. 11678 11679 When a parameter is copied into a pseudo-register at entry to a 11680 function, a note of this kind records that the register is 11681 equivalent to the stack slot where the parameter was passed. 11682 Although in this case the register may be set by other insns, it 11683 is still valid to replace the register by the stack slot 11684 throughout the function. 11685 11686 A `REG_EQUIV' note is also used on an instruction which copies a 11687 register parameter into a pseudo-register at entry to a function, 11688 if there is a stack slot where that parameter could be stored. 11689 Although other insns may set the pseudo-register, it is valid for 11690 the compiler to replace the pseudo-register by stack slot 11691 throughout the function, provided the compiler ensures that the 11692 stack slot is properly initialized by making the replacement in 11693 the initial copy instruction as well. This is used on machines 11694 for which the calling convention allocates stack space for 11695 register parameters. See `REG_PARM_STACK_SPACE' in *Note Stack 11696 Arguments::. 11697 11698 In the case of `REG_EQUAL', the register that is set by this insn 11699 will be equal to OP at run time at the end of this insn but not 11700 necessarily elsewhere in the function. In this case, OP is 11701 typically an arithmetic expression. For example, when a sequence 11702 of insns such as a library call is used to perform an arithmetic 11703 operation, this kind of note is attached to the insn that produces 11704 or copies the final value. 11705 11706 These two notes are used in different ways by the compiler passes. 11707 `REG_EQUAL' is used by passes prior to register allocation (such as 11708 common subexpression elimination and loop optimization) to tell 11709 them how to think of that value. `REG_EQUIV' notes are used by 11710 register allocation to indicate that there is an available 11711 substitute expression (either a constant or a `mem' expression for 11712 the location of a parameter on the stack) that may be used in 11713 place of a register if insufficient registers are available. 11714 11715 Except for stack homes for parameters, which are indicated by a 11716 `REG_EQUIV' note and are not useful to the early optimization 11717 passes and pseudo registers that are equivalent to a memory 11718 location throughout their entire life, which is not detected until 11719 later in the compilation, all equivalences are initially indicated 11720 by an attached `REG_EQUAL' note. In the early stages of register 11721 allocation, a `REG_EQUAL' note is changed into a `REG_EQUIV' note 11722 if OP is a constant and the insn represents the only set of its 11723 destination register. 11724 11725 Thus, compiler passes prior to register allocation need only check 11726 for `REG_EQUAL' notes and passes subsequent to register allocation 11727 need only check for `REG_EQUIV' notes. 11728 11729 These notes describe linkages between insns. They occur in pairs: one 11730 insn has one of a pair of notes that points to a second insn, which has 11731 the inverse note pointing back to the first insn. 11732 11733 `REG_CC_SETTER' 11734 `REG_CC_USER' 11735 On machines that use `cc0', the insns which set and use `cc0' set 11736 and use `cc0' are adjacent. However, when branch delay slot 11737 filling is done, this may no longer be true. In this case a 11738 `REG_CC_USER' note will be placed on the insn setting `cc0' to 11739 point to the insn using `cc0' and a `REG_CC_SETTER' note will be 11740 placed on the insn using `cc0' to point to the insn setting `cc0'. 11741 11742 These values are only used in the `LOG_LINKS' field, and indicate the 11743 type of dependency that each link represents. Links which indicate a 11744 data dependence (a read after write dependence) do not use any code, 11745 they simply have mode `VOIDmode', and are printed without any 11746 descriptive text. 11747 11748 `REG_DEP_TRUE' 11749 This indicates a true dependence (a read after write dependence). 11750 11751 `REG_DEP_OUTPUT' 11752 This indicates an output dependence (a write after write 11753 dependence). 11754 11755 `REG_DEP_ANTI' 11756 This indicates an anti dependence (a write after read dependence). 11757 11758 11759 These notes describe information gathered from gcov profile data. They 11760 are stored in the `REG_NOTES' field of an insn as an `expr_list'. 11761 11762 `REG_BR_PROB' 11763 This is used to specify the ratio of branches to non-branches of a 11764 branch insn according to the profile data. The value is stored as 11765 a value between 0 and REG_BR_PROB_BASE; larger values indicate a 11766 higher probability that the branch will be taken. 11767 11768 `REG_BR_PRED' 11769 These notes are found in JUMP insns after delayed branch scheduling 11770 has taken place. They indicate both the direction and the 11771 likelihood of the JUMP. The format is a bitmask of ATTR_FLAG_* 11772 values. 11773 11774 `REG_FRAME_RELATED_EXPR' 11775 This is used on an RTX_FRAME_RELATED_P insn wherein the attached 11776 expression is used in place of the actual insn pattern. This is 11777 done in cases where the pattern is either complex or misleading. 11778 11779 For convenience, the machine mode in an `insn_list' or `expr_list' is 11780 printed using these symbolic codes in debugging dumps. 11781 11782 The only difference between the expression codes `insn_list' and 11783 `expr_list' is that the first operand of an `insn_list' is assumed to 11784 be an insn and is printed in debugging dumps as the insn's unique id; 11785 the first operand of an `expr_list' is printed in the ordinary way as 11786 an expression. 11787 11788 11789 File: gccint.info, Node: Calls, Next: Sharing, Prev: Insns, Up: RTL 11790 11791 10.19 RTL Representation of Function-Call Insns 11792 =============================================== 11793 11794 Insns that call subroutines have the RTL expression code `call_insn'. 11795 These insns must satisfy special rules, and their bodies must use a 11796 special RTL expression code, `call'. 11797 11798 A `call' expression has two operands, as follows: 11799 11800 (call (mem:FM ADDR) NBYTES) 11801 11802 Here NBYTES is an operand that represents the number of bytes of 11803 argument data being passed to the subroutine, FM is a machine mode 11804 (which must equal as the definition of the `FUNCTION_MODE' macro in the 11805 machine description) and ADDR represents the address of the subroutine. 11806 11807 For a subroutine that returns no value, the `call' expression as shown 11808 above is the entire body of the insn, except that the insn might also 11809 contain `use' or `clobber' expressions. 11810 11811 For a subroutine that returns a value whose mode is not `BLKmode', the 11812 value is returned in a hard register. If this register's number is R, 11813 then the body of the call insn looks like this: 11814 11815 (set (reg:M R) 11816 (call (mem:FM ADDR) NBYTES)) 11817 11818 This RTL expression makes it clear (to the optimizer passes) that the 11819 appropriate register receives a useful value in this insn. 11820 11821 When a subroutine returns a `BLKmode' value, it is handled by passing 11822 to the subroutine the address of a place to store the value. So the 11823 call insn itself does not "return" any value, and it has the same RTL 11824 form as a call that returns nothing. 11825 11826 On some machines, the call instruction itself clobbers some register, 11827 for example to contain the return address. `call_insn' insns on these 11828 machines should have a body which is a `parallel' that contains both 11829 the `call' expression and `clobber' expressions that indicate which 11830 registers are destroyed. Similarly, if the call instruction requires 11831 some register other than the stack pointer that is not explicitly 11832 mentioned in its RTL, a `use' subexpression should mention that 11833 register. 11834 11835 Functions that are called are assumed to modify all registers listed in 11836 the configuration macro `CALL_USED_REGISTERS' (*note Register Basics::) 11837 and, with the exception of `const' functions and library calls, to 11838 modify all of memory. 11839 11840 Insns containing just `use' expressions directly precede the 11841 `call_insn' insn to indicate which registers contain inputs to the 11842 function. Similarly, if registers other than those in 11843 `CALL_USED_REGISTERS' are clobbered by the called function, insns 11844 containing a single `clobber' follow immediately after the call to 11845 indicate which registers. 11846 11847 11848 File: gccint.info, Node: Sharing, Next: Reading RTL, Prev: Calls, Up: RTL 11849 11850 10.20 Structure Sharing Assumptions 11851 =================================== 11852 11853 The compiler assumes that certain kinds of RTL expressions are unique; 11854 there do not exist two distinct objects representing the same value. 11855 In other cases, it makes an opposite assumption: that no RTL expression 11856 object of a certain kind appears in more than one place in the 11857 containing structure. 11858 11859 These assumptions refer to a single function; except for the RTL 11860 objects that describe global variables and external functions, and a 11861 few standard objects such as small integer constants, no RTL objects 11862 are common to two functions. 11863 11864 * Each pseudo-register has only a single `reg' object to represent 11865 it, and therefore only a single machine mode. 11866 11867 * For any symbolic label, there is only one `symbol_ref' object 11868 referring to it. 11869 11870 * All `const_int' expressions with equal values are shared. 11871 11872 * There is only one `pc' expression. 11873 11874 * There is only one `cc0' expression. 11875 11876 * There is only one `const_double' expression with value 0 for each 11877 floating point mode. Likewise for values 1 and 2. 11878 11879 * There is only one `const_vector' expression with value 0 for each 11880 vector mode, be it an integer or a double constant vector. 11881 11882 * No `label_ref' or `scratch' appears in more than one place in the 11883 RTL structure; in other words, it is safe to do a tree-walk of all 11884 the insns in the function and assume that each time a `label_ref' 11885 or `scratch' is seen it is distinct from all others that are seen. 11886 11887 * Only one `mem' object is normally created for each static variable 11888 or stack slot, so these objects are frequently shared in all the 11889 places they appear. However, separate but equal objects for these 11890 variables are occasionally made. 11891 11892 * When a single `asm' statement has multiple output operands, a 11893 distinct `asm_operands' expression is made for each output operand. 11894 However, these all share the vector which contains the sequence of 11895 input operands. This sharing is used later on to test whether two 11896 `asm_operands' expressions come from the same statement, so all 11897 optimizations must carefully preserve the sharing if they copy the 11898 vector at all. 11899 11900 * No RTL object appears in more than one place in the RTL structure 11901 except as described above. Many passes of the compiler rely on 11902 this by assuming that they can modify RTL objects in place without 11903 unwanted side-effects on other insns. 11904 11905 * During initial RTL generation, shared structure is freely 11906 introduced. After all the RTL for a function has been generated, 11907 all shared structure is copied by `unshare_all_rtl' in 11908 `emit-rtl.c', after which the above rules are guaranteed to be 11909 followed. 11910 11911 * During the combiner pass, shared structure within an insn can exist 11912 temporarily. However, the shared structure is copied before the 11913 combiner is finished with the insn. This is done by calling 11914 `copy_rtx_if_shared', which is a subroutine of `unshare_all_rtl'. 11915 11916 11917 File: gccint.info, Node: Reading RTL, Prev: Sharing, Up: RTL 11918 11919 10.21 Reading RTL 11920 ================= 11921 11922 To read an RTL object from a file, call `read_rtx'. It takes one 11923 argument, a stdio stream, and returns a single RTL object. This routine 11924 is defined in `read-rtl.c'. It is not available in the compiler 11925 itself, only the various programs that generate the compiler back end 11926 from the machine description. 11927 11928 People frequently have the idea of using RTL stored as text in a file 11929 as an interface between a language front end and the bulk of GCC. This 11930 idea is not feasible. 11931 11932 GCC was designed to use RTL internally only. Correct RTL for a given 11933 program is very dependent on the particular target machine. And the RTL 11934 does not contain all the information about the program. 11935 11936 The proper way to interface GCC to a new language front end is with 11937 the "tree" data structure, described in the files `tree.h' and 11938 `tree.def'. The documentation for this structure (*note Trees::) is 11939 incomplete. 11940 11941 11942 File: gccint.info, Node: GENERIC, Next: GIMPLE, Prev: RTL, Up: Top 11943 11944 11 GENERIC 11945 ********** 11946 11947 The purpose of GENERIC is simply to provide a language-independent way 11948 of representing an entire function in trees. To this end, it was 11949 necessary to add a few new tree codes to the back end, but most 11950 everything was already there. If you can express it with the codes in 11951 `gcc/tree.def', it's GENERIC. 11952 11953 Early on, there was a great deal of debate about how to think about 11954 statements in a tree IL. In GENERIC, a statement is defined as any 11955 expression whose value, if any, is ignored. A statement will always 11956 have `TREE_SIDE_EFFECTS' set (or it will be discarded), but a 11957 non-statement expression may also have side effects. A `CALL_EXPR', 11958 for instance. 11959 11960 It would be possible for some local optimizations to work on the 11961 GENERIC form of a function; indeed, the adapted tree inliner works fine 11962 on GENERIC, but the current compiler performs inlining after lowering 11963 to GIMPLE (a restricted form described in the next section). Indeed, 11964 currently the frontends perform this lowering before handing off to 11965 `tree_rest_of_compilation', but this seems inelegant. 11966 11967 If necessary, a front end can use some language-dependent tree codes 11968 in its GENERIC representation, so long as it provides a hook for 11969 converting them to GIMPLE and doesn't expect them to work with any 11970 (hypothetical) optimizers that run before the conversion to GIMPLE. The 11971 intermediate representation used while parsing C and C++ looks very 11972 little like GENERIC, but the C and C++ gimplifier hooks are perfectly 11973 happy to take it as input and spit out GIMPLE. 11974 11975 * Menu: 11976 11977 * Statements:: 11978 11979 11980 File: gccint.info, Node: Statements, Up: GENERIC 11981 11982 11.1 Statements 11983 =============== 11984 11985 Most statements in GIMPLE are assignment statements, represented by 11986 `GIMPLE_ASSIGN'. No other C expressions can appear at statement level; 11987 a reference to a volatile object is converted into a `GIMPLE_ASSIGN'. 11988 11989 There are also several varieties of complex statements. 11990 11991 * Menu: 11992 11993 * Blocks:: 11994 * Statement Sequences:: 11995 * Empty Statements:: 11996 * Jumps:: 11997 * Cleanups:: 11998 11999 12000 File: gccint.info, Node: Blocks, Next: Statement Sequences, Up: Statements 12001 12002 11.1.1 Blocks 12003 ------------- 12004 12005 Block scopes and the variables they declare in GENERIC are expressed 12006 using the `BIND_EXPR' code, which in previous versions of GCC was 12007 primarily used for the C statement-expression extension. 12008 12009 Variables in a block are collected into `BIND_EXPR_VARS' in 12010 declaration order. Any runtime initialization is moved out of 12011 `DECL_INITIAL' and into a statement in the controlled block. When 12012 gimplifying from C or C++, this initialization replaces the `DECL_STMT'. 12013 12014 Variable-length arrays (VLAs) complicate this process, as their size 12015 often refers to variables initialized earlier in the block. To handle 12016 this, we currently split the block at that point, and move the VLA into 12017 a new, inner `BIND_EXPR'. This strategy may change in the future. 12018 12019 A C++ program will usually contain more `BIND_EXPR's than there are 12020 syntactic blocks in the source code, since several C++ constructs have 12021 implicit scopes associated with them. On the other hand, although the 12022 C++ front end uses pseudo-scopes to handle cleanups for objects with 12023 destructors, these don't translate into the GIMPLE form; multiple 12024 declarations at the same level use the same `BIND_EXPR'. 12025 12026 12027 File: gccint.info, Node: Statement Sequences, Next: Empty Statements, Prev: Blocks, Up: Statements 12028 12029 11.1.2 Statement Sequences 12030 -------------------------- 12031 12032 Multiple statements at the same nesting level are collected into a 12033 `STATEMENT_LIST'. Statement lists are modified and traversed using the 12034 interface in `tree-iterator.h'. 12035 12036 12037 File: gccint.info, Node: Empty Statements, Next: Jumps, Prev: Statement Sequences, Up: Statements 12038 12039 11.1.3 Empty Statements 12040 ----------------------- 12041 12042 Whenever possible, statements with no effect are discarded. But if 12043 they are nested within another construct which cannot be discarded for 12044 some reason, they are instead replaced with an empty statement, 12045 generated by `build_empty_stmt'. Initially, all empty statements were 12046 shared, after the pattern of the Java front end, but this caused a lot 12047 of trouble in practice. 12048 12049 An empty statement is represented as `(void)0'. 12050 12051 12052 File: gccint.info, Node: Jumps, Next: Cleanups, Prev: Empty Statements, Up: Statements 12053 12054 11.1.4 Jumps 12055 ------------ 12056 12057 Other jumps are expressed by either `GOTO_EXPR' or `RETURN_EXPR'. 12058 12059 The operand of a `GOTO_EXPR' must be either a label or a variable 12060 containing the address to jump to. 12061 12062 The operand of a `RETURN_EXPR' is either `NULL_TREE', `RESULT_DECL', 12063 or a `MODIFY_EXPR' which sets the return value. It would be nice to 12064 move the `MODIFY_EXPR' into a separate statement, but the special 12065 return semantics in `expand_return' make that difficult. It may still 12066 happen in the future, perhaps by moving most of that logic into 12067 `expand_assignment'. 12068 12069 12070 File: gccint.info, Node: Cleanups, Prev: Jumps, Up: Statements 12071 12072 11.1.5 Cleanups 12073 --------------- 12074 12075 Destructors for local C++ objects and similar dynamic cleanups are 12076 represented in GIMPLE by a `TRY_FINALLY_EXPR'. `TRY_FINALLY_EXPR' has 12077 two operands, both of which are a sequence of statements to execute. 12078 The first sequence is executed. When it completes the second sequence 12079 is executed. 12080 12081 The first sequence may complete in the following ways: 12082 12083 1. Execute the last statement in the sequence and fall off the end. 12084 12085 2. Execute a goto statement (`GOTO_EXPR') to an ordinary label 12086 outside the sequence. 12087 12088 3. Execute a return statement (`RETURN_EXPR'). 12089 12090 4. Throw an exception. This is currently not explicitly represented 12091 in GIMPLE. 12092 12093 12094 The second sequence is not executed if the first sequence completes by 12095 calling `setjmp' or `exit' or any other function that does not return. 12096 The second sequence is also not executed if the first sequence 12097 completes via a non-local goto or a computed goto (in general the 12098 compiler does not know whether such a goto statement exits the first 12099 sequence or not, so we assume that it doesn't). 12100 12101 After the second sequence is executed, if it completes normally by 12102 falling off the end, execution continues wherever the first sequence 12103 would have continued, by falling off the end, or doing a goto, etc. 12104 12105 `TRY_FINALLY_EXPR' complicates the flow graph, since the cleanup needs 12106 to appear on every edge out of the controlled block; this reduces the 12107 freedom to move code across these edges. Therefore, the EH lowering 12108 pass which runs before most of the optimization passes eliminates these 12109 expressions by explicitly adding the cleanup to each edge. Rethrowing 12110 the exception is represented using `RESX_EXPR'. 12111 12112 12113 File: gccint.info, Node: GIMPLE, Next: Tree SSA, Prev: GENERIC, Up: Top 12114 12115 12 GIMPLE 12116 ********* 12117 12118 GIMPLE is a three-address representation derived from GENERIC by 12119 breaking down GENERIC expressions into tuples of no more than 3 12120 operands (with some exceptions like function calls). GIMPLE was 12121 heavily influenced by the SIMPLE IL used by the McCAT compiler project 12122 at McGill University, though we have made some different choices. For 12123 one thing, SIMPLE doesn't support `goto'. 12124 12125 Temporaries are introduced to hold intermediate values needed to 12126 compute complex expressions. Additionally, all the control structures 12127 used in GENERIC are lowered into conditional jumps, lexical scopes are 12128 removed and exception regions are converted into an on the side 12129 exception region tree. 12130 12131 The compiler pass which converts GENERIC into GIMPLE is referred to as 12132 the `gimplifier'. The gimplifier works recursively, generating GIMPLE 12133 tuples out of the original GENERIC expressions. 12134 12135 One of the early implementation strategies used for the GIMPLE 12136 representation was to use the same internal data structures used by 12137 front ends to represent parse trees. This simplified implementation 12138 because we could leverage existing functionality and interfaces. 12139 However, GIMPLE is a much more restrictive representation than abstract 12140 syntax trees (AST), therefore it does not require the full structural 12141 complexity provided by the main tree data structure. 12142 12143 The GENERIC representation of a function is stored in the 12144 `DECL_SAVED_TREE' field of the associated `FUNCTION_DECL' tree node. 12145 It is converted to GIMPLE by a call to `gimplify_function_tree'. 12146 12147 If a front end wants to include language-specific tree codes in the 12148 tree representation which it provides to the back end, it must provide a 12149 definition of `LANG_HOOKS_GIMPLIFY_EXPR' which knows how to convert the 12150 front end trees to GIMPLE. Usually such a hook will involve much of 12151 the same code for expanding front end trees to RTL. This function can 12152 return fully lowered GIMPLE, or it can return GENERIC trees and let the 12153 main gimplifier lower them the rest of the way; this is often simpler. 12154 GIMPLE that is not fully lowered is known as "High GIMPLE" and consists 12155 of the IL before the pass `pass_lower_cf'. High GIMPLE contains some 12156 container statements like lexical scopes (represented by `GIMPLE_BIND') 12157 and nested expressions (e.g., `GIMPLE_TRY'), while "Low GIMPLE" exposes 12158 all of the implicit jumps for control and exception expressions 12159 directly in the IL and EH region trees. 12160 12161 The C and C++ front ends currently convert directly from front end 12162 trees to GIMPLE, and hand that off to the back end rather than first 12163 converting to GENERIC. Their gimplifier hooks know about all the 12164 `_STMT' nodes and how to convert them to GENERIC forms. There was some 12165 work done on a genericization pass which would run first, but the 12166 existence of `STMT_EXPR' meant that in order to convert all of the C 12167 statements into GENERIC equivalents would involve walking the entire 12168 tree anyway, so it was simpler to lower all the way. This might change 12169 in the future if someone writes an optimization pass which would work 12170 better with higher-level trees, but currently the optimizers all expect 12171 GIMPLE. 12172 12173 You can request to dump a C-like representation of the GIMPLE form 12174 with the flag `-fdump-tree-gimple'. 12175 12176 * Menu: 12177 12178 * Tuple representation:: 12179 * GIMPLE instruction set:: 12180 * GIMPLE Exception Handling:: 12181 * Temporaries:: 12182 * Operands:: 12183 * Manipulating GIMPLE statements:: 12184 * Tuple specific accessors:: 12185 * GIMPLE sequences:: 12186 * Sequence iterators:: 12187 * Adding a new GIMPLE statement code:: 12188 * Statement and operand traversals:: 12189 12190 12191 File: gccint.info, Node: Tuple representation, Next: GIMPLE instruction set, Up: GIMPLE 12192 12193 12.1 Tuple representation 12194 ========================= 12195 12196 GIMPLE instructions are tuples of variable size divided in two groups: 12197 a header describing the instruction and its locations, and a variable 12198 length body with all the operands. Tuples are organized into a 12199 hierarchy with 3 main classes of tuples. 12200 12201 12.1.1 `gimple_statement_base' (gsbase) 12202 --------------------------------------- 12203 12204 This is the root of the hierarchy, it holds basic information needed by 12205 most GIMPLE statements. There are some fields that may not be relevant 12206 to every GIMPLE statement, but those were moved into the base structure 12207 to take advantage of holes left by other fields (thus making the 12208 structure more compact). The structure takes 4 words (32 bytes) on 64 12209 bit hosts: 12210 12211 Field Size (bits) 12212 `code' 8 12213 `subcode' 16 12214 `no_warning' 1 12215 `visited' 1 12216 `nontemporal_move' 1 12217 `plf' 2 12218 `modified' 1 12219 `has_volatile_ops' 1 12220 `references_memory_p' 1 12221 `uid' 32 12222 `location' 32 12223 `num_ops' 32 12224 `bb' 64 12225 `block' 63 12226 Total size 32 bytes 12227 12228 * `code' Main identifier for a GIMPLE instruction. 12229 12230 * `subcode' Used to distinguish different variants of the same basic 12231 instruction or provide flags applicable to a given code. The 12232 `subcode' flags field has different uses depending on the code of 12233 the instruction, but mostly it distinguishes instructions of the 12234 same family. The most prominent use of this field is in 12235 assignments, where subcode indicates the operation done on the RHS 12236 of the assignment. For example, a = b + c is encoded as 12237 `GIMPLE_ASSIGN <PLUS_EXPR, a, b, c>'. 12238 12239 * `no_warning' Bitflag to indicate whether a warning has already 12240 been issued on this statement. 12241 12242 * `visited' General purpose "visited" marker. Set and cleared by 12243 each pass when needed. 12244 12245 * `nontemporal_move' Bitflag used in assignments that represent 12246 non-temporal moves. Although this bitflag is only used in 12247 assignments, it was moved into the base to take advantage of the 12248 bit holes left by the previous fields. 12249 12250 * `plf' Pass Local Flags. This 2-bit mask can be used as general 12251 purpose markers by any pass. Passes are responsible for clearing 12252 and setting these two flags accordingly. 12253 12254 * `modified' Bitflag to indicate whether the statement has been 12255 modified. Used mainly by the operand scanner to determine when to 12256 re-scan a statement for operands. 12257 12258 * `has_volatile_ops' Bitflag to indicate whether this statement 12259 contains operands that have been marked volatile. 12260 12261 * `references_memory_p' Bitflag to indicate whether this statement 12262 contains memory references (i.e., its operands are either global 12263 variables, or pointer dereferences or anything that must reside in 12264 memory). 12265 12266 * `uid' This is an unsigned integer used by passes that want to 12267 assign IDs to every statement. These IDs must be assigned and used 12268 by each pass. 12269 12270 * `location' This is a `location_t' identifier to specify source code 12271 location for this statement. It is inherited from the front end. 12272 12273 * `num_ops' Number of operands that this statement has. This 12274 specifies the size of the operand vector embedded in the tuple. 12275 Only used in some tuples, but it is declared in the base tuple to 12276 take advantage of the 32-bit hole left by the previous fields. 12277 12278 * `bb' Basic block holding the instruction. 12279 12280 * `block' Lexical block holding this statement. Also used for debug 12281 information generation. 12282 12283 12.1.2 `gimple_statement_with_ops' 12284 ---------------------------------- 12285 12286 This tuple is actually split in two: `gimple_statement_with_ops_base' 12287 and `gimple_statement_with_ops'. This is needed to accommodate the way 12288 the operand vector is allocated. The operand vector is defined to be an 12289 array of 1 element. So, to allocate a dynamic number of operands, the 12290 memory allocator (`gimple_alloc') simply allocates enough memory to 12291 hold the structure itself plus `N - 1' operands which run "off the end" 12292 of the structure. For example, to allocate space for a tuple with 3 12293 operands, `gimple_alloc' reserves `sizeof (struct 12294 gimple_statement_with_ops) + 2 * sizeof (tree)' bytes. 12295 12296 On the other hand, several fields in this tuple need to be shared with 12297 the `gimple_statement_with_memory_ops' tuple. So, these common fields 12298 are placed in `gimple_statement_with_ops_base' which is then inherited 12299 from the other two tuples. 12300 12301 `gsbase' 256 12302 `addresses_taken' 64 12303 `def_ops' 64 12304 `use_ops' 64 12305 `op' `num_ops' * 64 12306 Total size 56 + 8 * `num_ops' bytes 12307 12308 * `gsbase' Inherited from `struct gimple_statement_base'. 12309 12310 * `addresses_taken' Bitmap holding the UIDs of all the `VAR_DECL's 12311 whose addresses are taken by this statement. For example, a 12312 statement of the form `p = &b' will have the UID for symbol `b' in 12313 this set. 12314 12315 * `def_ops' Array of pointers into the operand array indicating all 12316 the slots that contain a variable written-to by the statement. 12317 This array is also used for immediate use chaining. Note that it 12318 would be possible to not rely on this array, but the changes 12319 required to implement this are pretty invasive. 12320 12321 * `use_ops' Similar to `def_ops' but for variables read by the 12322 statement. 12323 12324 * `op' Array of trees with `num_ops' slots. 12325 12326 12.1.3 `gimple_statement_with_memory_ops' 12327 ----------------------------------------- 12328 12329 This tuple is essentially identical to `gimple_statement_with_ops', 12330 except that it contains 4 additional fields to hold vectors related 12331 memory stores and loads. Similar to the previous case, the structure 12332 is split in two to accommodate for the operand vector 12333 (`gimple_statement_with_memory_ops_base' and 12334 `gimple_statement_with_memory_ops'). 12335 12336 Field Size (bits) 12337 `gsbase' 256 12338 `addresses_taken' 64 12339 `def_ops' 64 12340 `use_ops' 64 12341 `vdef_ops' 64 12342 `vuse_ops' 64 12343 `stores' 64 12344 `loads' 64 12345 `op' `num_ops' * 64 12346 Total size 88 + 8 * `num_ops' bytes 12347 12348 * `vdef_ops' Similar to `def_ops' but for `VDEF' operators. There is 12349 one entry per memory symbol written by this statement. This is 12350 used to maintain the memory SSA use-def and def-def chains. 12351 12352 * `vuse_ops' Similar to `use_ops' but for `VUSE' operators. There is 12353 one entry per memory symbol loaded by this statement. This is used 12354 to maintain the memory SSA use-def chains. 12355 12356 * `stores' Bitset with all the UIDs for the symbols written-to by the 12357 statement. This is different than `vdef_ops' in that all the 12358 affected symbols are mentioned in this set. If memory 12359 partitioning is enabled, the `vdef_ops' vector will refer to memory 12360 partitions. Furthermore, no SSA information is stored in this set. 12361 12362 * `loads' Similar to `stores', but for memory loads. (Note that there 12363 is some amount of redundancy here, it should be possible to reduce 12364 memory utilization further by removing these sets). 12365 12366 All the other tuples are defined in terms of these three basic ones. 12367 Each tuple will add some fields. The main gimple type is defined to be 12368 the union of all these structures (`GTY' markers elided for clarity): 12369 12370 union gimple_statement_d 12371 { 12372 struct gimple_statement_base gsbase; 12373 struct gimple_statement_with_ops gsops; 12374 struct gimple_statement_with_memory_ops gsmem; 12375 struct gimple_statement_omp omp; 12376 struct gimple_statement_bind gimple_bind; 12377 struct gimple_statement_catch gimple_catch; 12378 struct gimple_statement_eh_filter gimple_eh_filter; 12379 struct gimple_statement_phi gimple_phi; 12380 struct gimple_statement_resx gimple_resx; 12381 struct gimple_statement_try gimple_try; 12382 struct gimple_statement_wce gimple_wce; 12383 struct gimple_statement_asm gimple_asm; 12384 struct gimple_statement_omp_critical gimple_omp_critical; 12385 struct gimple_statement_omp_for gimple_omp_for; 12386 struct gimple_statement_omp_parallel gimple_omp_parallel; 12387 struct gimple_statement_omp_task gimple_omp_task; 12388 struct gimple_statement_omp_sections gimple_omp_sections; 12389 struct gimple_statement_omp_single gimple_omp_single; 12390 struct gimple_statement_omp_continue gimple_omp_continue; 12391 struct gimple_statement_omp_atomic_load gimple_omp_atomic_load; 12392 struct gimple_statement_omp_atomic_store gimple_omp_atomic_store; 12393 }; 12394 12395 12396 File: gccint.info, Node: GIMPLE instruction set, Next: GIMPLE Exception Handling, Prev: Tuple representation, Up: GIMPLE 12397 12398 12.2 GIMPLE instruction set 12399 =========================== 12400 12401 The following table briefly describes the GIMPLE instruction set. 12402 12403 Instruction High GIMPLE Low GIMPLE 12404 `GIMPLE_ASM' x x 12405 `GIMPLE_ASSIGN' x x 12406 `GIMPLE_BIND' x 12407 `GIMPLE_CALL' x x 12408 `GIMPLE_CATCH' x 12409 `GIMPLE_CHANGE_DYNAMIC_TYPE' x x 12410 `GIMPLE_COND' x x 12411 `GIMPLE_EH_FILTER' x 12412 `GIMPLE_GOTO' x x 12413 `GIMPLE_LABEL' x x 12414 `GIMPLE_NOP' x x 12415 `GIMPLE_OMP_ATOMIC_LOAD' x x 12416 `GIMPLE_OMP_ATOMIC_STORE' x x 12417 `GIMPLE_OMP_CONTINUE' x x 12418 `GIMPLE_OMP_CRITICAL' x x 12419 `GIMPLE_OMP_FOR' x x 12420 `GIMPLE_OMP_MASTER' x x 12421 `GIMPLE_OMP_ORDERED' x x 12422 `GIMPLE_OMP_PARALLEL' x x 12423 `GIMPLE_OMP_RETURN' x x 12424 `GIMPLE_OMP_SECTION' x x 12425 `GIMPLE_OMP_SECTIONS' x x 12426 `GIMPLE_OMP_SECTIONS_SWITCH' x x 12427 `GIMPLE_OMP_SINGLE' x x 12428 `GIMPLE_PHI' x 12429 `GIMPLE_RESX' x 12430 `GIMPLE_RETURN' x x 12431 `GIMPLE_SWITCH' x x 12432 `GIMPLE_TRY' x 12433 12434 12435 File: gccint.info, Node: GIMPLE Exception Handling, Next: Temporaries, Prev: GIMPLE instruction set, Up: GIMPLE 12436 12437 12.3 Exception Handling 12438 ======================= 12439 12440 Other exception handling constructs are represented using 12441 `GIMPLE_TRY_CATCH'. `GIMPLE_TRY_CATCH' has two operands. The first 12442 operand is a sequence of statements to execute. If executing these 12443 statements does not throw an exception, then the second operand is 12444 ignored. Otherwise, if an exception is thrown, then the second operand 12445 of the `GIMPLE_TRY_CATCH' is checked. The second operand may have the 12446 following forms: 12447 12448 1. A sequence of statements to execute. When an exception occurs, 12449 these statements are executed, and then the exception is rethrown. 12450 12451 2. A sequence of `GIMPLE_CATCH' statements. Each `GIMPLE_CATCH' has 12452 a list of applicable exception types and handler code. If the 12453 thrown exception matches one of the caught types, the associated 12454 handler code is executed. If the handler code falls off the 12455 bottom, execution continues after the original `GIMPLE_TRY_CATCH'. 12456 12457 3. An `GIMPLE_EH_FILTER' statement. This has a list of permitted 12458 exception types, and code to handle a match failure. If the 12459 thrown exception does not match one of the allowed types, the 12460 associated match failure code is executed. If the thrown exception 12461 does match, it continues unwinding the stack looking for the next 12462 handler. 12463 12464 12465 Currently throwing an exception is not directly represented in GIMPLE, 12466 since it is implemented by calling a function. At some point in the 12467 future we will want to add some way to express that the call will throw 12468 an exception of a known type. 12469 12470 Just before running the optimizers, the compiler lowers the high-level 12471 EH constructs above into a set of `goto's, magic labels, and EH 12472 regions. Continuing to unwind at the end of a cleanup is represented 12473 with a `GIMPLE_RESX'. 12474 12475 12476 File: gccint.info, Node: Temporaries, Next: Operands, Prev: GIMPLE Exception Handling, Up: GIMPLE 12477 12478 12.4 Temporaries 12479 ================ 12480 12481 When gimplification encounters a subexpression that is too complex, it 12482 creates a new temporary variable to hold the value of the 12483 subexpression, and adds a new statement to initialize it before the 12484 current statement. These special temporaries are known as `expression 12485 temporaries', and are allocated using `get_formal_tmp_var'. The 12486 compiler tries to always evaluate identical expressions into the same 12487 temporary, to simplify elimination of redundant calculations. 12488 12489 We can only use expression temporaries when we know that it will not 12490 be reevaluated before its value is used, and that it will not be 12491 otherwise modified(1). Other temporaries can be allocated using 12492 `get_initialized_tmp_var' or `create_tmp_var'. 12493 12494 Currently, an expression like `a = b + 5' is not reduced any further. 12495 We tried converting it to something like 12496 T1 = b + 5; 12497 a = T1; 12498 but this bloated the representation for minimal benefit. However, a 12499 variable which must live in memory cannot appear in an expression; its 12500 value is explicitly loaded into a temporary first. Similarly, storing 12501 the value of an expression to a memory variable goes through a 12502 temporary. 12503 12504 ---------- Footnotes ---------- 12505 12506 (1) These restrictions are derived from those in Morgan 4.8. 12507 12508 12509 File: gccint.info, Node: Operands, Next: Manipulating GIMPLE statements, Prev: Temporaries, Up: GIMPLE 12510 12511 12.5 Operands 12512 ============= 12513 12514 In general, expressions in GIMPLE consist of an operation and the 12515 appropriate number of simple operands; these operands must either be a 12516 GIMPLE rvalue (`is_gimple_val'), i.e. a constant or a register 12517 variable. More complex operands are factored out into temporaries, so 12518 that 12519 a = b + c + d 12520 becomes 12521 T1 = b + c; 12522 a = T1 + d; 12523 12524 The same rule holds for arguments to a `GIMPLE_CALL'. 12525 12526 The target of an assignment is usually a variable, but can also be an 12527 `INDIRECT_REF' or a compound lvalue as described below. 12528 12529 * Menu: 12530 12531 * Compound Expressions:: 12532 * Compound Lvalues:: 12533 * Conditional Expressions:: 12534 * Logical Operators:: 12535 12536 12537 File: gccint.info, Node: Compound Expressions, Next: Compound Lvalues, Up: Operands 12538 12539 12.5.1 Compound Expressions 12540 --------------------------- 12541 12542 The left-hand side of a C comma expression is simply moved into a 12543 separate statement. 12544 12545 12546 File: gccint.info, Node: Compound Lvalues, Next: Conditional Expressions, Prev: Compound Expressions, Up: Operands 12547 12548 12.5.2 Compound Lvalues 12549 ----------------------- 12550 12551 Currently compound lvalues involving array and structure field 12552 references are not broken down; an expression like `a.b[2] = 42' is not 12553 reduced any further (though complex array subscripts are). This 12554 restriction is a workaround for limitations in later optimizers; if we 12555 were to convert this to 12556 12557 T1 = &a.b; 12558 T1[2] = 42; 12559 12560 alias analysis would not remember that the reference to `T1[2]' came 12561 by way of `a.b', so it would think that the assignment could alias 12562 another member of `a'; this broke `struct-alias-1.c'. Future optimizer 12563 improvements may make this limitation unnecessary. 12564 12565 12566 File: gccint.info, Node: Conditional Expressions, Next: Logical Operators, Prev: Compound Lvalues, Up: Operands 12567 12568 12.5.3 Conditional Expressions 12569 ------------------------------ 12570 12571 A C `?:' expression is converted into an `if' statement with each 12572 branch assigning to the same temporary. So, 12573 12574 a = b ? c : d; 12575 becomes 12576 if (b == 1) 12577 T1 = c; 12578 else 12579 T1 = d; 12580 a = T1; 12581 12582 The GIMPLE level if-conversion pass re-introduces `?:' expression, if 12583 appropriate. It is used to vectorize loops with conditions using vector 12584 conditional operations. 12585 12586 Note that in GIMPLE, `if' statements are represented using 12587 `GIMPLE_COND', as described below. 12588 12589 12590 File: gccint.info, Node: Logical Operators, Prev: Conditional Expressions, Up: Operands 12591 12592 12.5.4 Logical Operators 12593 ------------------------ 12594 12595 Except when they appear in the condition operand of a `GIMPLE_COND', 12596 logical `and' and `or' operators are simplified as follows: `a = b && 12597 c' becomes 12598 12599 T1 = (bool)b; 12600 if (T1 == true) 12601 T1 = (bool)c; 12602 a = T1; 12603 12604 Note that `T1' in this example cannot be an expression temporary, 12605 because it has two different assignments. 12606 12607 12.5.5 Manipulating operands 12608 ---------------------------- 12609 12610 All gimple operands are of type `tree'. But only certain types of 12611 trees are allowed to be used as operand tuples. Basic validation is 12612 controlled by the function `get_gimple_rhs_class', which given a tree 12613 code, returns an `enum' with the following values of type `enum 12614 gimple_rhs_class' 12615 12616 * `GIMPLE_INVALID_RHS' The tree cannot be used as a GIMPLE operand. 12617 12618 * `GIMPLE_BINARY_RHS' The tree is a valid GIMPLE binary operation. 12619 12620 * `GIMPLE_UNARY_RHS' The tree is a valid GIMPLE unary operation. 12621 12622 * `GIMPLE_SINGLE_RHS' The tree is a single object, that cannot be 12623 split into simpler operands (for instance, `SSA_NAME', `VAR_DECL', 12624 `COMPONENT_REF', etc). 12625 12626 This operand class also acts as an escape hatch for tree nodes 12627 that may be flattened out into the operand vector, but would need 12628 more than two slots on the RHS. For instance, a `COND_EXPR' 12629 expression of the form `(a op b) ? x : y' could be flattened out 12630 on the operand vector using 4 slots, but it would also require 12631 additional processing to distinguish `c = a op b' from `c = a op b 12632 ? x : y'. Something similar occurs with `ASSERT_EXPR'. In time, 12633 these special case tree expressions should be flattened into the 12634 operand vector. 12635 12636 For tree nodes in the categories `GIMPLE_BINARY_RHS' and 12637 `GIMPLE_UNARY_RHS', they cannot be stored inside tuples directly. They 12638 first need to be flattened and separated into individual components. 12639 For instance, given the GENERIC expression 12640 12641 a = b + c 12642 12643 its tree representation is: 12644 12645 MODIFY_EXPR <VAR_DECL <a>, PLUS_EXPR <VAR_DECL <b>, VAR_DECL <c>>> 12646 12647 In this case, the GIMPLE form for this statement is logically 12648 identical to its GENERIC form but in GIMPLE, the `PLUS_EXPR' on the RHS 12649 of the assignment is not represented as a tree, instead the two 12650 operands are taken out of the `PLUS_EXPR' sub-tree and flattened into 12651 the GIMPLE tuple as follows: 12652 12653 GIMPLE_ASSIGN <PLUS_EXPR, VAR_DECL <a>, VAR_DECL <b>, VAR_DECL <c>> 12654 12655 12.5.6 Operand vector allocation 12656 -------------------------------- 12657 12658 The operand vector is stored at the bottom of the three tuple 12659 structures that accept operands. This means, that depending on the code 12660 of a given statement, its operand vector will be at different offsets 12661 from the base of the structure. To access tuple operands use the 12662 following accessors 12663 12664 -- GIMPLE function: unsigned gimple_num_ops (gimple g) 12665 Returns the number of operands in statement G. 12666 12667 -- GIMPLE function: tree gimple_op (gimple g, unsigned i) 12668 Returns operand `I' from statement `G'. 12669 12670 -- GIMPLE function: tree *gimple_ops (gimple g) 12671 Returns a pointer into the operand vector for statement `G'. This 12672 is computed using an internal table called `gimple_ops_offset_'[]. 12673 This table is indexed by the gimple code of `G'. 12674 12675 When the compiler is built, this table is filled-in using the 12676 sizes of the structures used by each statement code defined in 12677 gimple.def. Since the operand vector is at the bottom of the 12678 structure, for a gimple code `C' the offset is computed as sizeof 12679 (struct-of `C') - sizeof (tree). 12680 12681 This mechanism adds one memory indirection to every access when 12682 using `gimple_op'(), if this becomes a bottleneck, a pass can 12683 choose to memoize the result from `gimple_ops'() and use that to 12684 access the operands. 12685 12686 12.5.7 Operand validation 12687 ------------------------- 12688 12689 When adding a new operand to a gimple statement, the operand will be 12690 validated according to what each tuple accepts in its operand vector. 12691 These predicates are called by the `gimple_<name>_set_...()'. Each 12692 tuple will use one of the following predicates (Note, this list is not 12693 exhaustive): 12694 12695 -- GIMPLE function: is_gimple_operand (tree t) 12696 This is the most permissive of the predicates. It essentially 12697 checks whether t has a `gimple_rhs_class' of `GIMPLE_SINGLE_RHS'. 12698 12699 -- GIMPLE function: is_gimple_val (tree t) 12700 Returns true if t is a "GIMPLE value", which are all the 12701 non-addressable stack variables (variables for which 12702 `is_gimple_reg' returns true) and constants (expressions for which 12703 `is_gimple_min_invariant' returns true). 12704 12705 -- GIMPLE function: is_gimple_addressable (tree t) 12706 Returns true if t is a symbol or memory reference whose address 12707 can be taken. 12708 12709 -- GIMPLE function: is_gimple_asm_val (tree t) 12710 Similar to `is_gimple_val' but it also accepts hard registers. 12711 12712 -- GIMPLE function: is_gimple_call_addr (tree t) 12713 Return true if t is a valid expression to use as the function 12714 called by a `GIMPLE_CALL'. 12715 12716 -- GIMPLE function: is_gimple_constant (tree t) 12717 Return true if t is a valid gimple constant. 12718 12719 -- GIMPLE function: is_gimple_min_invariant (tree t) 12720 Return true if t is a valid minimal invariant. This is different 12721 from constants, in that the specific value of t may not be known 12722 at compile time, but it is known that it doesn't change (e.g., the 12723 address of a function local variable). 12724 12725 -- GIMPLE function: is_gimple_min_invariant_address (tree t) 12726 Return true if t is an `ADDR_EXPR' that does not change once the 12727 program is running. 12728 12729 12.5.8 Statement validation 12730 --------------------------- 12731 12732 -- GIMPLE function: is_gimple_assign (gimple g) 12733 Return true if the code of g is `GIMPLE_ASSIGN'. 12734 12735 -- GIMPLE function: is_gimple_call (gimple g) 12736 Return true if the code of g is `GIMPLE_CALL' 12737 12738 -- GIMPLE function: gimple_assign_cast_p (gimple g) 12739 Return true if g is a `GIMPLE_ASSIGN' that performs a type cast 12740 operation 12741 12742 12743 File: gccint.info, Node: Manipulating GIMPLE statements, Next: Tuple specific accessors, Prev: Operands, Up: GIMPLE 12744 12745 12.6 Manipulating GIMPLE statements 12746 =================================== 12747 12748 This section documents all the functions available to handle each of 12749 the GIMPLE instructions. 12750 12751 12.6.1 Common accessors 12752 ----------------------- 12753 12754 The following are common accessors for gimple statements. 12755 12756 -- GIMPLE function: enum gimple_code gimple_code (gimple g) 12757 Return the code for statement `G'. 12758 12759 -- GIMPLE function: basic_block gimple_bb (gimple g) 12760 Return the basic block to which statement `G' belongs to. 12761 12762 -- GIMPLE function: tree gimple_block (gimple g) 12763 Return the lexical scope block holding statement `G'. 12764 12765 -- GIMPLE function: tree gimple_expr_type (gimple stmt) 12766 Return the type of the main expression computed by `STMT'. Return 12767 `void_type_node' if `STMT' computes nothing. This will only return 12768 something meaningful for `GIMPLE_ASSIGN', `GIMPLE_COND' and 12769 `GIMPLE_CALL'. For all other tuple codes, it will return 12770 `void_type_node'. 12771 12772 -- GIMPLE function: enum tree_code gimple_expr_code (gimple stmt) 12773 Return the tree code for the expression computed by `STMT'. This 12774 is only meaningful for `GIMPLE_CALL', `GIMPLE_ASSIGN' and 12775 `GIMPLE_COND'. If `STMT' is `GIMPLE_CALL', it will return 12776 `CALL_EXPR'. For `GIMPLE_COND', it returns the code of the 12777 comparison predicate. For `GIMPLE_ASSIGN' it returns the code of 12778 the operation performed by the `RHS' of the assignment. 12779 12780 -- GIMPLE function: void gimple_set_block (gimple g, tree block) 12781 Set the lexical scope block of `G' to `BLOCK'. 12782 12783 -- GIMPLE function: location_t gimple_locus (gimple g) 12784 Return locus information for statement `G'. 12785 12786 -- GIMPLE function: void gimple_set_locus (gimple g, location_t locus) 12787 Set locus information for statement `G'. 12788 12789 -- GIMPLE function: bool gimple_locus_empty_p (gimple g) 12790 Return true if `G' does not have locus information. 12791 12792 -- GIMPLE function: bool gimple_no_warning_p (gimple stmt) 12793 Return true if no warnings should be emitted for statement `STMT'. 12794 12795 -- GIMPLE function: void gimple_set_visited (gimple stmt, bool 12796 visited_p) 12797 Set the visited status on statement `STMT' to `VISITED_P'. 12798 12799 -- GIMPLE function: bool gimple_visited_p (gimple stmt) 12800 Return the visited status on statement `STMT'. 12801 12802 -- GIMPLE function: void gimple_set_plf (gimple stmt, enum plf_mask 12803 plf, bool val_p) 12804 Set pass local flag `PLF' on statement `STMT' to `VAL_P'. 12805 12806 -- GIMPLE function: unsigned int gimple_plf (gimple stmt, enum 12807 plf_mask plf) 12808 Return the value of pass local flag `PLF' on statement `STMT'. 12809 12810 -- GIMPLE function: bool gimple_has_ops (gimple g) 12811 Return true if statement `G' has register or memory operands. 12812 12813 -- GIMPLE function: bool gimple_has_mem_ops (gimple g) 12814 Return true if statement `G' has memory operands. 12815 12816 -- GIMPLE function: unsigned gimple_num_ops (gimple g) 12817 Return the number of operands for statement `G'. 12818 12819 -- GIMPLE function: tree *gimple_ops (gimple g) 12820 Return the array of operands for statement `G'. 12821 12822 -- GIMPLE function: tree gimple_op (gimple g, unsigned i) 12823 Return operand `I' for statement `G'. 12824 12825 -- GIMPLE function: tree *gimple_op_ptr (gimple g, unsigned i) 12826 Return a pointer to operand `I' for statement `G'. 12827 12828 -- GIMPLE function: void gimple_set_op (gimple g, unsigned i, tree op) 12829 Set operand `I' of statement `G' to `OP'. 12830 12831 -- GIMPLE function: bitmap gimple_addresses_taken (gimple stmt) 12832 Return the set of symbols that have had their address taken by 12833 `STMT'. 12834 12835 -- GIMPLE function: struct def_optype_d *gimple_def_ops (gimple g) 12836 Return the set of `DEF' operands for statement `G'. 12837 12838 -- GIMPLE function: void gimple_set_def_ops (gimple g, struct 12839 def_optype_d *def) 12840 Set `DEF' to be the set of `DEF' operands for statement `G'. 12841 12842 -- GIMPLE function: struct use_optype_d *gimple_use_ops (gimple g) 12843 Return the set of `USE' operands for statement `G'. 12844 12845 -- GIMPLE function: void gimple_set_use_ops (gimple g, struct 12846 use_optype_d *use) 12847 Set `USE' to be the set of `USE' operands for statement `G'. 12848 12849 -- GIMPLE function: struct voptype_d *gimple_vuse_ops (gimple g) 12850 Return the set of `VUSE' operands for statement `G'. 12851 12852 -- GIMPLE function: void gimple_set_vuse_ops (gimple g, struct 12853 voptype_d *ops) 12854 Set `OPS' to be the set of `VUSE' operands for statement `G'. 12855 12856 -- GIMPLE function: struct voptype_d *gimple_vdef_ops (gimple g) 12857 Return the set of `VDEF' operands for statement `G'. 12858 12859 -- GIMPLE function: void gimple_set_vdef_ops (gimple g, struct 12860 voptype_d *ops) 12861 Set `OPS' to be the set of `VDEF' operands for statement `G'. 12862 12863 -- GIMPLE function: bitmap gimple_loaded_syms (gimple g) 12864 Return the set of symbols loaded by statement `G'. Each element of 12865 the set is the `DECL_UID' of the corresponding symbol. 12866 12867 -- GIMPLE function: bitmap gimple_stored_syms (gimple g) 12868 Return the set of symbols stored by statement `G'. Each element of 12869 the set is the `DECL_UID' of the corresponding symbol. 12870 12871 -- GIMPLE function: bool gimple_modified_p (gimple g) 12872 Return true if statement `G' has operands and the modified field 12873 has been set. 12874 12875 -- GIMPLE function: bool gimple_has_volatile_ops (gimple stmt) 12876 Return true if statement `STMT' contains volatile operands. 12877 12878 -- GIMPLE function: void gimple_set_has_volatile_ops (gimple stmt, 12879 bool volatilep) 12880 Return true if statement `STMT' contains volatile operands. 12881 12882 -- GIMPLE function: void update_stmt (gimple s) 12883 Mark statement `S' as modified, and update it. 12884 12885 -- GIMPLE function: void update_stmt_if_modified (gimple s) 12886 Update statement `S' if it has been marked modified. 12887 12888 -- GIMPLE function: gimple gimple_copy (gimple stmt) 12889 Return a deep copy of statement `STMT'. 12890 12891 12892 File: gccint.info, Node: Tuple specific accessors, Next: GIMPLE sequences, Prev: Manipulating GIMPLE statements, Up: GIMPLE 12893 12894 12.7 Tuple specific accessors 12895 ============================= 12896 12897 * Menu: 12898 12899 * `GIMPLE_ASM':: 12900 * `GIMPLE_ASSIGN':: 12901 * `GIMPLE_BIND':: 12902 * `GIMPLE_CALL':: 12903 * `GIMPLE_CATCH':: 12904 * `GIMPLE_CHANGE_DYNAMIC_TYPE':: 12905 * `GIMPLE_COND':: 12906 * `GIMPLE_EH_FILTER':: 12907 * `GIMPLE_LABEL':: 12908 * `GIMPLE_NOP':: 12909 * `GIMPLE_OMP_ATOMIC_LOAD':: 12910 * `GIMPLE_OMP_ATOMIC_STORE':: 12911 * `GIMPLE_OMP_CONTINUE':: 12912 * `GIMPLE_OMP_CRITICAL':: 12913 * `GIMPLE_OMP_FOR':: 12914 * `GIMPLE_OMP_MASTER':: 12915 * `GIMPLE_OMP_ORDERED':: 12916 * `GIMPLE_OMP_PARALLEL':: 12917 * `GIMPLE_OMP_RETURN':: 12918 * `GIMPLE_OMP_SECTION':: 12919 * `GIMPLE_OMP_SECTIONS':: 12920 * `GIMPLE_OMP_SINGLE':: 12921 * `GIMPLE_PHI':: 12922 * `GIMPLE_RESX':: 12923 * `GIMPLE_RETURN':: 12924 * `GIMPLE_SWITCH':: 12925 * `GIMPLE_TRY':: 12926 * `GIMPLE_WITH_CLEANUP_EXPR':: 12927 12928 12929 File: gccint.info, Node: `GIMPLE_ASM', Next: `GIMPLE_ASSIGN', Up: Tuple specific accessors 12930 12931 12.7.1 `GIMPLE_ASM' 12932 ------------------- 12933 12934 -- GIMPLE function: gimple gimple_build_asm (const char *string, 12935 ninputs, noutputs, nclobbers, ...) 12936 Build a `GIMPLE_ASM' statement. This statement is used for 12937 building in-line assembly constructs. `STRING' is the assembly 12938 code. `NINPUT' is the number of register inputs. `NOUTPUT' is the 12939 number of register outputs. `NCLOBBERS' is the number of clobbered 12940 registers. The rest of the arguments trees for each input, 12941 output, and clobbered registers. 12942 12943 -- GIMPLE function: gimple gimple_build_asm_vec (const char *, 12944 VEC(tree,gc) *, VEC(tree,gc) *, VEC(tree,gc) *) 12945 Identical to gimple_build_asm, but the arguments are passed in 12946 VECs. 12947 12948 -- GIMPLE function: gimple_asm_ninputs (gimple g) 12949 Return the number of input operands for `GIMPLE_ASM' `G'. 12950 12951 -- GIMPLE function: gimple_asm_noutputs (gimple g) 12952 Return the number of output operands for `GIMPLE_ASM' `G'. 12953 12954 -- GIMPLE function: gimple_asm_nclobbers (gimple g) 12955 Return the number of clobber operands for `GIMPLE_ASM' `G'. 12956 12957 -- GIMPLE function: tree gimple_asm_input_op (gimple g, unsigned index) 12958 Return input operand `INDEX' of `GIMPLE_ASM' `G'. 12959 12960 -- GIMPLE function: void gimple_asm_set_input_op (gimple g, unsigned 12961 index, tree in_op) 12962 Set `IN_OP' to be input operand `INDEX' in `GIMPLE_ASM' `G'. 12963 12964 -- GIMPLE function: tree gimple_asm_output_op (gimple g, unsigned 12965 index) 12966 Return output operand `INDEX' of `GIMPLE_ASM' `G'. 12967 12968 -- GIMPLE function: void gimple_asm_set_output_op (gimple g, unsigned 12969 index, tree out_op) 12970 Set `OUT_OP' to be output operand `INDEX' in `GIMPLE_ASM' `G'. 12971 12972 -- GIMPLE function: tree gimple_asm_clobber_op (gimple g, unsigned 12973 index) 12974 Return clobber operand `INDEX' of `GIMPLE_ASM' `G'. 12975 12976 -- GIMPLE function: void gimple_asm_set_clobber_op (gimple g, unsigned 12977 index, tree clobber_op) 12978 Set `CLOBBER_OP' to be clobber operand `INDEX' in `GIMPLE_ASM' `G'. 12979 12980 -- GIMPLE function: const char *gimple_asm_string (gimple g) 12981 Return the string representing the assembly instruction in 12982 `GIMPLE_ASM' `G'. 12983 12984 -- GIMPLE function: bool gimple_asm_volatile_p (gimple g) 12985 Return true if `G' is an asm statement marked volatile. 12986 12987 -- GIMPLE function: void gimple_asm_set_volatile (gimple g) 12988 Mark asm statement `G' as volatile. 12989 12990 -- GIMPLE function: void gimple_asm_clear_volatile (gimple g) 12991 Remove volatile marker from asm statement `G'. 12992 12993 12994 File: gccint.info, Node: `GIMPLE_ASSIGN', Next: `GIMPLE_BIND', Prev: `GIMPLE_ASM', Up: Tuple specific accessors 12995 12996 12.7.2 `GIMPLE_ASSIGN' 12997 ---------------------- 12998 12999 -- GIMPLE function: gimple gimple_build_assign (tree lhs, tree rhs) 13000 Build a `GIMPLE_ASSIGN' statement. The left-hand side is an lvalue 13001 passed in lhs. The right-hand side can be either a unary or 13002 binary tree expression. The expression tree rhs will be flattened 13003 and its operands assigned to the corresponding operand slots in 13004 the new statement. This function is useful when you already have 13005 a tree expression that you want to convert into a tuple. However, 13006 try to avoid building expression trees for the sole purpose of 13007 calling this function. If you already have the operands in 13008 separate trees, it is better to use `gimple_build_assign_with_ops'. 13009 13010 -- GIMPLE function: gimple gimplify_assign (tree dst, tree src, 13011 gimple_seq *seq_p) 13012 Build a new `GIMPLE_ASSIGN' tuple and append it to the end of 13013 `*SEQ_P'. 13014 13015 `DST'/`SRC' are the destination and source respectively. You can pass 13016 ungimplified trees in `DST' or `SRC', in which case they will be 13017 converted to a gimple operand if necessary. 13018 13019 This function returns the newly created `GIMPLE_ASSIGN' tuple. 13020 13021 -- GIMPLE function: gimple gimple_build_assign_with_ops (enum 13022 tree_code subcode, tree lhs, tree op1, tree op2) 13023 This function is similar to `gimple_build_assign', but is used to 13024 build a `GIMPLE_ASSIGN' statement when the operands of the 13025 right-hand side of the assignment are already split into different 13026 operands. 13027 13028 The left-hand side is an lvalue passed in lhs. Subcode is the 13029 `tree_code' for the right-hand side of the assignment. Op1 and op2 13030 are the operands. If op2 is null, subcode must be a `tree_code' 13031 for a unary expression. 13032 13033 -- GIMPLE function: enum tree_code gimple_assign_rhs_code (gimple g) 13034 Return the code of the expression computed on the `RHS' of 13035 assignment statement `G'. 13036 13037 -- GIMPLE function: enum gimple_rhs_class gimple_assign_rhs_class 13038 (gimple g) 13039 Return the gimple rhs class of the code for the expression 13040 computed on the rhs of assignment statement `G'. This will never 13041 return `GIMPLE_INVALID_RHS'. 13042 13043 -- GIMPLE function: tree gimple_assign_lhs (gimple g) 13044 Return the `LHS' of assignment statement `G'. 13045 13046 -- GIMPLE function: tree *gimple_assign_lhs_ptr (gimple g) 13047 Return a pointer to the `LHS' of assignment statement `G'. 13048 13049 -- GIMPLE function: tree gimple_assign_rhs1 (gimple g) 13050 Return the first operand on the `RHS' of assignment statement `G'. 13051 13052 -- GIMPLE function: tree *gimple_assign_rhs1_ptr (gimple g) 13053 Return the address of the first operand on the `RHS' of assignment 13054 statement `G'. 13055 13056 -- GIMPLE function: tree gimple_assign_rhs2 (gimple g) 13057 Return the second operand on the `RHS' of assignment statement `G'. 13058 13059 -- GIMPLE function: tree *gimple_assign_rhs2_ptr (gimple g) 13060 Return the address of the second operand on the `RHS' of assignment 13061 statement `G'. 13062 13063 -- GIMPLE function: void gimple_assign_set_lhs (gimple g, tree lhs) 13064 Set `LHS' to be the `LHS' operand of assignment statement `G'. 13065 13066 -- GIMPLE function: void gimple_assign_set_rhs1 (gimple g, tree rhs) 13067 Set `RHS' to be the first operand on the `RHS' of assignment 13068 statement `G'. 13069 13070 -- GIMPLE function: tree gimple_assign_rhs2 (gimple g) 13071 Return the second operand on the `RHS' of assignment statement `G'. 13072 13073 -- GIMPLE function: tree *gimple_assign_rhs2_ptr (gimple g) 13074 Return a pointer to the second operand on the `RHS' of assignment 13075 statement `G'. 13076 13077 -- GIMPLE function: void gimple_assign_set_rhs2 (gimple g, tree rhs) 13078 Set `RHS' to be the second operand on the `RHS' of assignment 13079 statement `G'. 13080 13081 -- GIMPLE function: bool gimple_assign_cast_p (gimple s) 13082 Return true if `S' is an type-cast assignment. 13083 13084 13085 File: gccint.info, Node: `GIMPLE_BIND', Next: `GIMPLE_CALL', Prev: `GIMPLE_ASSIGN', Up: Tuple specific accessors 13086 13087 12.7.3 `GIMPLE_BIND' 13088 -------------------- 13089 13090 -- GIMPLE function: gimple gimple_build_bind (tree vars, gimple_seq 13091 body) 13092 Build a `GIMPLE_BIND' statement with a list of variables in `VARS' 13093 and a body of statements in sequence `BODY'. 13094 13095 -- GIMPLE function: tree gimple_bind_vars (gimple g) 13096 Return the variables declared in the `GIMPLE_BIND' statement `G'. 13097 13098 -- GIMPLE function: void gimple_bind_set_vars (gimple g, tree vars) 13099 Set `VARS' to be the set of variables declared in the `GIMPLE_BIND' 13100 statement `G'. 13101 13102 -- GIMPLE function: void gimple_bind_append_vars (gimple g, tree vars) 13103 Append `VARS' to the set of variables declared in the `GIMPLE_BIND' 13104 statement `G'. 13105 13106 -- GIMPLE function: gimple_seq gimple_bind_body (gimple g) 13107 Return the GIMPLE sequence contained in the `GIMPLE_BIND' statement 13108 `G'. 13109 13110 -- GIMPLE function: void gimple_bind_set_body (gimple g, gimple_seq 13111 seq) 13112 Set `SEQ' to be sequence contained in the `GIMPLE_BIND' statement 13113 `G'. 13114 13115 -- GIMPLE function: void gimple_bind_add_stmt (gimple gs, gimple stmt) 13116 Append a statement to the end of a `GIMPLE_BIND''s body. 13117 13118 -- GIMPLE function: void gimple_bind_add_seq (gimple gs, gimple_seq 13119 seq) 13120 Append a sequence of statements to the end of a `GIMPLE_BIND''s 13121 body. 13122 13123 -- GIMPLE function: tree gimple_bind_block (gimple g) 13124 Return the `TREE_BLOCK' node associated with `GIMPLE_BIND' 13125 statement `G'. This is analogous to the `BIND_EXPR_BLOCK' field in 13126 trees. 13127 13128 -- GIMPLE function: void gimple_bind_set_block (gimple g, tree block) 13129 Set `BLOCK' to be the `TREE_BLOCK' node associated with 13130 `GIMPLE_BIND' statement `G'. 13131 13132 13133 File: gccint.info, Node: `GIMPLE_CALL', Next: `GIMPLE_CATCH', Prev: `GIMPLE_BIND', Up: Tuple specific accessors 13134 13135 12.7.4 `GIMPLE_CALL' 13136 -------------------- 13137 13138 -- GIMPLE function: gimple gimple_build_call (tree fn, unsigned nargs, 13139 ...) 13140 Build a `GIMPLE_CALL' statement to function `FN'. The argument 13141 `FN' must be either a `FUNCTION_DECL' or a gimple call address as 13142 determined by `is_gimple_call_addr'. `NARGS' are the number of 13143 arguments. The rest of the arguments follow the argument `NARGS', 13144 and must be trees that are valid as rvalues in gimple (i.e., each 13145 operand is validated with `is_gimple_operand'). 13146 13147 -- GIMPLE function: gimple gimple_build_call_from_tree (tree call_expr) 13148 Build a `GIMPLE_CALL' from a `CALL_EXPR' node. The arguments and 13149 the function are taken from the expression directly. This routine 13150 assumes that `call_expr' is already in GIMPLE form. That is, its 13151 operands are GIMPLE values and the function call needs no further 13152 simplification. All the call flags in `call_expr' are copied over 13153 to the new `GIMPLE_CALL'. 13154 13155 -- GIMPLE function: gimple gimple_build_call_vec (tree fn, `VEC'(tree, 13156 heap) *args) 13157 Identical to `gimple_build_call' but the arguments are stored in a 13158 `VEC'(). 13159 13160 -- GIMPLE function: tree gimple_call_lhs (gimple g) 13161 Return the `LHS' of call statement `G'. 13162 13163 -- GIMPLE function: tree *gimple_call_lhs_ptr (gimple g) 13164 Return a pointer to the `LHS' of call statement `G'. 13165 13166 -- GIMPLE function: void gimple_call_set_lhs (gimple g, tree lhs) 13167 Set `LHS' to be the `LHS' operand of call statement `G'. 13168 13169 -- GIMPLE function: tree gimple_call_fn (gimple g) 13170 Return the tree node representing the function called by call 13171 statement `G'. 13172 13173 -- GIMPLE function: void gimple_call_set_fn (gimple g, tree fn) 13174 Set `FN' to be the function called by call statement `G'. This has 13175 to be a gimple value specifying the address of the called function. 13176 13177 -- GIMPLE function: tree gimple_call_fndecl (gimple g) 13178 If a given `GIMPLE_CALL''s callee is a `FUNCTION_DECL', return it. 13179 Otherwise return `NULL'. This function is analogous to 13180 `get_callee_fndecl' in `GENERIC'. 13181 13182 -- GIMPLE function: tree gimple_call_set_fndecl (gimple g, tree fndecl) 13183 Set the called function to `FNDECL'. 13184 13185 -- GIMPLE function: tree gimple_call_return_type (gimple g) 13186 Return the type returned by call statement `G'. 13187 13188 -- GIMPLE function: tree gimple_call_chain (gimple g) 13189 Return the static chain for call statement `G'. 13190 13191 -- GIMPLE function: void gimple_call_set_chain (gimple g, tree chain) 13192 Set `CHAIN' to be the static chain for call statement `G'. 13193 13194 -- GIMPLE function: gimple_call_num_args (gimple g) 13195 Return the number of arguments used by call statement `G'. 13196 13197 -- GIMPLE function: tree gimple_call_arg (gimple g, unsigned index) 13198 Return the argument at position `INDEX' for call statement `G'. 13199 The first argument is 0. 13200 13201 -- GIMPLE function: tree *gimple_call_arg_ptr (gimple g, unsigned 13202 index) 13203 Return a pointer to the argument at position `INDEX' for call 13204 statement `G'. 13205 13206 -- GIMPLE function: void gimple_call_set_arg (gimple g, unsigned 13207 index, tree arg) 13208 Set `ARG' to be the argument at position `INDEX' for call statement 13209 `G'. 13210 13211 -- GIMPLE function: void gimple_call_set_tail (gimple s) 13212 Mark call statement `S' as being a tail call (i.e., a call just 13213 before the exit of a function). These calls are candidate for tail 13214 call optimization. 13215 13216 -- GIMPLE function: bool gimple_call_tail_p (gimple s) 13217 Return true if `GIMPLE_CALL' `S' is marked as a tail call. 13218 13219 -- GIMPLE function: void gimple_call_mark_uninlinable (gimple s) 13220 Mark `GIMPLE_CALL' `S' as being uninlinable. 13221 13222 -- GIMPLE function: bool gimple_call_cannot_inline_p (gimple s) 13223 Return true if `GIMPLE_CALL' `S' cannot be inlined. 13224 13225 -- GIMPLE function: bool gimple_call_noreturn_p (gimple s) 13226 Return true if `S' is a noreturn call. 13227 13228 -- GIMPLE function: gimple gimple_call_copy_skip_args (gimple stmt, 13229 bitmap args_to_skip) 13230 Build a `GIMPLE_CALL' identical to `STMT' but skipping the 13231 arguments in the positions marked by the set `ARGS_TO_SKIP'. 13232 13233 13234 File: gccint.info, Node: `GIMPLE_CATCH', Next: `GIMPLE_CHANGE_DYNAMIC_TYPE', Prev: `GIMPLE_CALL', Up: Tuple specific accessors 13235 13236 12.7.5 `GIMPLE_CATCH' 13237 --------------------- 13238 13239 -- GIMPLE function: gimple gimple_build_catch (tree types, gimple_seq 13240 handler) 13241 Build a `GIMPLE_CATCH' statement. `TYPES' are the tree types this 13242 catch handles. `HANDLER' is a sequence of statements with the code 13243 for the handler. 13244 13245 -- GIMPLE function: tree gimple_catch_types (gimple g) 13246 Return the types handled by `GIMPLE_CATCH' statement `G'. 13247 13248 -- GIMPLE function: tree *gimple_catch_types_ptr (gimple g) 13249 Return a pointer to the types handled by `GIMPLE_CATCH' statement 13250 `G'. 13251 13252 -- GIMPLE function: gimple_seq gimple_catch_handler (gimple g) 13253 Return the GIMPLE sequence representing the body of the handler of 13254 `GIMPLE_CATCH' statement `G'. 13255 13256 -- GIMPLE function: void gimple_catch_set_types (gimple g, tree t) 13257 Set `T' to be the set of types handled by `GIMPLE_CATCH' `G'. 13258 13259 -- GIMPLE function: void gimple_catch_set_handler (gimple g, 13260 gimple_seq handler) 13261 Set `HANDLER' to be the body of `GIMPLE_CATCH' `G'. 13262 13263 13264 File: gccint.info, Node: `GIMPLE_CHANGE_DYNAMIC_TYPE', Next: `GIMPLE_COND', Prev: `GIMPLE_CATCH', Up: Tuple specific accessors 13265 13266 12.7.6 `GIMPLE_CHANGE_DYNAMIC_TYPE' 13267 ----------------------------------- 13268 13269 -- GIMPLE function: gimple gimple_build_cdt (tree type, tree ptr) 13270 Build a `GIMPLE_CHANGE_DYNAMIC_TYPE' statement. `TYPE' is the new 13271 type for the location `PTR'. 13272 13273 -- GIMPLE function: tree gimple_cdt_new_type (gimple g) 13274 Return the new type set by `GIMPLE_CHANGE_DYNAMIC_TYPE' statement 13275 `G'. 13276 13277 -- GIMPLE function: tree *gimple_cdt_new_type_ptr (gimple g) 13278 Return a pointer to the new type set by 13279 `GIMPLE_CHANGE_DYNAMIC_TYPE' statement `G'. 13280 13281 -- GIMPLE function: void gimple_cdt_set_new_type (gimple g, tree 13282 new_type) 13283 Set `NEW_TYPE' to be the type returned by 13284 `GIMPLE_CHANGE_DYNAMIC_TYPE' statement `G'. 13285 13286 -- GIMPLE function: tree gimple_cdt_location (gimple g) 13287 Return the location affected by `GIMPLE_CHANGE_DYNAMIC_TYPE' 13288 statement `G'. 13289 13290 -- GIMPLE function: tree *gimple_cdt_location_ptr (gimple g) 13291 Return a pointer to the location affected by 13292 `GIMPLE_CHANGE_DYNAMIC_TYPE' statement `G'. 13293 13294 -- GIMPLE function: void gimple_cdt_set_location (gimple g, tree ptr) 13295 Set `PTR' to be the location affected by 13296 `GIMPLE_CHANGE_DYNAMIC_TYPE' statement `G'. 13297 13298 13299 File: gccint.info, Node: `GIMPLE_COND', Next: `GIMPLE_EH_FILTER', Prev: `GIMPLE_CHANGE_DYNAMIC_TYPE', Up: Tuple specific accessors 13300 13301 12.7.7 `GIMPLE_COND' 13302 -------------------- 13303 13304 -- GIMPLE function: gimple gimple_build_cond (enum tree_code 13305 pred_code, tree lhs, tree rhs, tree t_label, tree f_label) 13306 Build a `GIMPLE_COND' statement. `A' `GIMPLE_COND' statement 13307 compares `LHS' and `RHS' and if the condition in `PRED_CODE' is 13308 true, jump to the label in `t_label', otherwise jump to the label 13309 in `f_label'. `PRED_CODE' are relational operator tree codes like 13310 `EQ_EXPR', `LT_EXPR', `LE_EXPR', `NE_EXPR', etc. 13311 13312 -- GIMPLE function: gimple gimple_build_cond_from_tree (tree cond, 13313 tree t_label, tree f_label) 13314 Build a `GIMPLE_COND' statement from the conditional expression 13315 tree `COND'. `T_LABEL' and `F_LABEL' are as in 13316 `gimple_build_cond'. 13317 13318 -- GIMPLE function: enum tree_code gimple_cond_code (gimple g) 13319 Return the code of the predicate computed by conditional statement 13320 `G'. 13321 13322 -- GIMPLE function: void gimple_cond_set_code (gimple g, enum 13323 tree_code code) 13324 Set `CODE' to be the predicate code for the conditional statement 13325 `G'. 13326 13327 -- GIMPLE function: tree gimple_cond_lhs (gimple g) 13328 Return the `LHS' of the predicate computed by conditional statement 13329 `G'. 13330 13331 -- GIMPLE function: void gimple_cond_set_lhs (gimple g, tree lhs) 13332 Set `LHS' to be the `LHS' operand of the predicate computed by 13333 conditional statement `G'. 13334 13335 -- GIMPLE function: tree gimple_cond_rhs (gimple g) 13336 Return the `RHS' operand of the predicate computed by conditional 13337 `G'. 13338 13339 -- GIMPLE function: void gimple_cond_set_rhs (gimple g, tree rhs) 13340 Set `RHS' to be the `RHS' operand of the predicate computed by 13341 conditional statement `G'. 13342 13343 -- GIMPLE function: tree gimple_cond_true_label (gimple g) 13344 Return the label used by conditional statement `G' when its 13345 predicate evaluates to true. 13346 13347 -- GIMPLE function: void gimple_cond_set_true_label (gimple g, tree 13348 label) 13349 Set `LABEL' to be the label used by conditional statement `G' when 13350 its predicate evaluates to true. 13351 13352 -- GIMPLE function: void gimple_cond_set_false_label (gimple g, tree 13353 label) 13354 Set `LABEL' to be the label used by conditional statement `G' when 13355 its predicate evaluates to false. 13356 13357 -- GIMPLE function: tree gimple_cond_false_label (gimple g) 13358 Return the label used by conditional statement `G' when its 13359 predicate evaluates to false. 13360 13361 -- GIMPLE function: void gimple_cond_make_false (gimple g) 13362 Set the conditional `COND_STMT' to be of the form 'if (1 == 0)'. 13363 13364 -- GIMPLE function: void gimple_cond_make_true (gimple g) 13365 Set the conditional `COND_STMT' to be of the form 'if (1 == 1)'. 13366 13367 13368 File: gccint.info, Node: `GIMPLE_EH_FILTER', Next: `GIMPLE_LABEL', Prev: `GIMPLE_COND', Up: Tuple specific accessors 13369 13370 12.7.8 `GIMPLE_EH_FILTER' 13371 ------------------------- 13372 13373 -- GIMPLE function: gimple gimple_build_eh_filter (tree types, 13374 gimple_seq failure) 13375 Build a `GIMPLE_EH_FILTER' statement. `TYPES' are the filter's 13376 types. `FAILURE' is a sequence with the filter's failure action. 13377 13378 -- GIMPLE function: tree gimple_eh_filter_types (gimple g) 13379 Return the types handled by `GIMPLE_EH_FILTER' statement `G'. 13380 13381 -- GIMPLE function: tree *gimple_eh_filter_types_ptr (gimple g) 13382 Return a pointer to the types handled by `GIMPLE_EH_FILTER' 13383 statement `G'. 13384 13385 -- GIMPLE function: gimple_seq gimple_eh_filter_failure (gimple g) 13386 Return the sequence of statement to execute when `GIMPLE_EH_FILTER' 13387 statement fails. 13388 13389 -- GIMPLE function: void gimple_eh_filter_set_types (gimple g, tree 13390 types) 13391 Set `TYPES' to be the set of types handled by `GIMPLE_EH_FILTER' 13392 `G'. 13393 13394 -- GIMPLE function: void gimple_eh_filter_set_failure (gimple g, 13395 gimple_seq failure) 13396 Set `FAILURE' to be the sequence of statements to execute on 13397 failure for `GIMPLE_EH_FILTER' `G'. 13398 13399 -- GIMPLE function: bool gimple_eh_filter_must_not_throw (gimple g) 13400 Return the `EH_FILTER_MUST_NOT_THROW' flag. 13401 13402 -- GIMPLE function: void gimple_eh_filter_set_must_not_throw (gimple 13403 g, bool mntp) 13404 Set the `EH_FILTER_MUST_NOT_THROW' flag. 13405 13406 13407 File: gccint.info, Node: `GIMPLE_LABEL', Next: `GIMPLE_NOP', Prev: `GIMPLE_EH_FILTER', Up: Tuple specific accessors 13408 13409 12.7.9 `GIMPLE_LABEL' 13410 --------------------- 13411 13412 -- GIMPLE function: gimple gimple_build_label (tree label) 13413 Build a `GIMPLE_LABEL' statement with corresponding to the tree 13414 label, `LABEL'. 13415 13416 -- GIMPLE function: tree gimple_label_label (gimple g) 13417 Return the `LABEL_DECL' node used by `GIMPLE_LABEL' statement `G'. 13418 13419 -- GIMPLE function: void gimple_label_set_label (gimple g, tree label) 13420 Set `LABEL' to be the `LABEL_DECL' node used by `GIMPLE_LABEL' 13421 statement `G'. 13422 13423 -- GIMPLE function: gimple gimple_build_goto (tree dest) 13424 Build a `GIMPLE_GOTO' statement to label `DEST'. 13425 13426 -- GIMPLE function: tree gimple_goto_dest (gimple g) 13427 Return the destination of the unconditional jump `G'. 13428 13429 -- GIMPLE function: void gimple_goto_set_dest (gimple g, tree dest) 13430 Set `DEST' to be the destination of the unconditional jump `G'. 13431 13432 13433 File: gccint.info, Node: `GIMPLE_NOP', Next: `GIMPLE_OMP_ATOMIC_LOAD', Prev: `GIMPLE_LABEL', Up: Tuple specific accessors 13434 13435 12.7.10 `GIMPLE_NOP' 13436 -------------------- 13437 13438 -- GIMPLE function: gimple gimple_build_nop (void) 13439 Build a `GIMPLE_NOP' statement. 13440 13441 -- GIMPLE function: bool gimple_nop_p (gimple g) 13442 Returns `TRUE' if statement `G' is a `GIMPLE_NOP'. 13443 13444 13445 File: gccint.info, Node: `GIMPLE_OMP_ATOMIC_LOAD', Next: `GIMPLE_OMP_ATOMIC_STORE', Prev: `GIMPLE_NOP', Up: Tuple specific accessors 13446 13447 12.7.11 `GIMPLE_OMP_ATOMIC_LOAD' 13448 -------------------------------- 13449 13450 -- GIMPLE function: gimple gimple_build_omp_atomic_load (tree lhs, 13451 tree rhs) 13452 Build a `GIMPLE_OMP_ATOMIC_LOAD' statement. `LHS' is the left-hand 13453 side of the assignment. `RHS' is the right-hand side of the 13454 assignment. 13455 13456 -- GIMPLE function: void gimple_omp_atomic_load_set_lhs (gimple g, 13457 tree lhs) 13458 Set the `LHS' of an atomic load. 13459 13460 -- GIMPLE function: tree gimple_omp_atomic_load_lhs (gimple g) 13461 Get the `LHS' of an atomic load. 13462 13463 -- GIMPLE function: void gimple_omp_atomic_load_set_rhs (gimple g, 13464 tree rhs) 13465 Set the `RHS' of an atomic set. 13466 13467 -- GIMPLE function: tree gimple_omp_atomic_load_rhs (gimple g) 13468 Get the `RHS' of an atomic set. 13469 13470 13471 File: gccint.info, Node: `GIMPLE_OMP_ATOMIC_STORE', Next: `GIMPLE_OMP_CONTINUE', Prev: `GIMPLE_OMP_ATOMIC_LOAD', Up: Tuple specific accessors 13472 13473 12.7.12 `GIMPLE_OMP_ATOMIC_STORE' 13474 --------------------------------- 13475 13476 -- GIMPLE function: gimple gimple_build_omp_atomic_store (tree val) 13477 Build a `GIMPLE_OMP_ATOMIC_STORE' statement. `VAL' is the value to 13478 be stored. 13479 13480 -- GIMPLE function: void gimple_omp_atomic_store_set_val (gimple g, 13481 tree val) 13482 Set the value being stored in an atomic store. 13483 13484 -- GIMPLE function: tree gimple_omp_atomic_store_val (gimple g) 13485 Return the value being stored in an atomic store. 13486 13487 13488 File: gccint.info, Node: `GIMPLE_OMP_CONTINUE', Next: `GIMPLE_OMP_CRITICAL', Prev: `GIMPLE_OMP_ATOMIC_STORE', Up: Tuple specific accessors 13489 13490 12.7.13 `GIMPLE_OMP_CONTINUE' 13491 ----------------------------- 13492 13493 -- GIMPLE function: gimple gimple_build_omp_continue (tree 13494 control_def, tree control_use) 13495 Build a `GIMPLE_OMP_CONTINUE' statement. `CONTROL_DEF' is the 13496 definition of the control variable. `CONTROL_USE' is the use of 13497 the control variable. 13498 13499 -- GIMPLE function: tree gimple_omp_continue_control_def (gimple s) 13500 Return the definition of the control variable on a 13501 `GIMPLE_OMP_CONTINUE' in `S'. 13502 13503 -- GIMPLE function: tree gimple_omp_continue_control_def_ptr (gimple s) 13504 Same as above, but return the pointer. 13505 13506 -- GIMPLE function: tree gimple_omp_continue_set_control_def (gimple s) 13507 Set the control variable definition for a `GIMPLE_OMP_CONTINUE' 13508 statement in `S'. 13509 13510 -- GIMPLE function: tree gimple_omp_continue_control_use (gimple s) 13511 Return the use of the control variable on a `GIMPLE_OMP_CONTINUE' 13512 in `S'. 13513 13514 -- GIMPLE function: tree gimple_omp_continue_control_use_ptr (gimple s) 13515 Same as above, but return the pointer. 13516 13517 -- GIMPLE function: tree gimple_omp_continue_set_control_use (gimple s) 13518 Set the control variable use for a `GIMPLE_OMP_CONTINUE' statement 13519 in `S'. 13520 13521 13522 File: gccint.info, Node: `GIMPLE_OMP_CRITICAL', Next: `GIMPLE_OMP_FOR', Prev: `GIMPLE_OMP_CONTINUE', Up: Tuple specific accessors 13523 13524 12.7.14 `GIMPLE_OMP_CRITICAL' 13525 ----------------------------- 13526 13527 -- GIMPLE function: gimple gimple_build_omp_critical (gimple_seq body, 13528 tree name) 13529 Build a `GIMPLE_OMP_CRITICAL' statement. `BODY' is the sequence of 13530 statements for which only one thread can execute. `NAME' is an 13531 optional identifier for this critical block. 13532 13533 -- GIMPLE function: tree gimple_omp_critical_name (gimple g) 13534 Return the name associated with `OMP_CRITICAL' statement `G'. 13535 13536 -- GIMPLE function: tree *gimple_omp_critical_name_ptr (gimple g) 13537 Return a pointer to the name associated with `OMP' critical 13538 statement `G'. 13539 13540 -- GIMPLE function: void gimple_omp_critical_set_name (gimple g, tree 13541 name) 13542 Set `NAME' to be the name associated with `OMP' critical statement 13543 `G'. 13544 13545 13546 File: gccint.info, Node: `GIMPLE_OMP_FOR', Next: `GIMPLE_OMP_MASTER', Prev: `GIMPLE_OMP_CRITICAL', Up: Tuple specific accessors 13547 13548 12.7.15 `GIMPLE_OMP_FOR' 13549 ------------------------ 13550 13551 -- GIMPLE function: gimple gimple_build_omp_for (gimple_seq body, tree 13552 clauses, tree index, tree initial, tree final, tree incr, 13553 gimple_seq pre_body, enum tree_code omp_for_cond) 13554 Build a `GIMPLE_OMP_FOR' statement. `BODY' is sequence of 13555 statements inside the for loop. `CLAUSES', are any of the `OMP' 13556 loop construct's clauses: private, firstprivate, lastprivate, 13557 reductions, ordered, schedule, and nowait. `PRE_BODY' is the 13558 sequence of statements that are loop invariant. `INDEX' is the 13559 index variable. `INITIAL' is the initial value of `INDEX'. 13560 `FINAL' is final value of `INDEX'. OMP_FOR_COND is the predicate 13561 used to compare `INDEX' and `FINAL'. `INCR' is the increment 13562 expression. 13563 13564 -- GIMPLE function: tree gimple_omp_for_clauses (gimple g) 13565 Return the clauses associated with `OMP_FOR' `G'. 13566 13567 -- GIMPLE function: tree *gimple_omp_for_clauses_ptr (gimple g) 13568 Return a pointer to the `OMP_FOR' `G'. 13569 13570 -- GIMPLE function: void gimple_omp_for_set_clauses (gimple g, tree 13571 clauses) 13572 Set `CLAUSES' to be the list of clauses associated with `OMP_FOR' 13573 `G'. 13574 13575 -- GIMPLE function: tree gimple_omp_for_index (gimple g) 13576 Return the index variable for `OMP_FOR' `G'. 13577 13578 -- GIMPLE function: tree *gimple_omp_for_index_ptr (gimple g) 13579 Return a pointer to the index variable for `OMP_FOR' `G'. 13580 13581 -- GIMPLE function: void gimple_omp_for_set_index (gimple g, tree 13582 index) 13583 Set `INDEX' to be the index variable for `OMP_FOR' `G'. 13584 13585 -- GIMPLE function: tree gimple_omp_for_initial (gimple g) 13586 Return the initial value for `OMP_FOR' `G'. 13587 13588 -- GIMPLE function: tree *gimple_omp_for_initial_ptr (gimple g) 13589 Return a pointer to the initial value for `OMP_FOR' `G'. 13590 13591 -- GIMPLE function: void gimple_omp_for_set_initial (gimple g, tree 13592 initial) 13593 Set `INITIAL' to be the initial value for `OMP_FOR' `G'. 13594 13595 -- GIMPLE function: tree gimple_omp_for_final (gimple g) 13596 Return the final value for `OMP_FOR' `G'. 13597 13598 -- GIMPLE function: tree *gimple_omp_for_final_ptr (gimple g) 13599 turn a pointer to the final value for `OMP_FOR' `G'. 13600 13601 -- GIMPLE function: void gimple_omp_for_set_final (gimple g, tree 13602 final) 13603 Set `FINAL' to be the final value for `OMP_FOR' `G'. 13604 13605 -- GIMPLE function: tree gimple_omp_for_incr (gimple g) 13606 Return the increment value for `OMP_FOR' `G'. 13607 13608 -- GIMPLE function: tree *gimple_omp_for_incr_ptr (gimple g) 13609 Return a pointer to the increment value for `OMP_FOR' `G'. 13610 13611 -- GIMPLE function: void gimple_omp_for_set_incr (gimple g, tree incr) 13612 Set `INCR' to be the increment value for `OMP_FOR' `G'. 13613 13614 -- GIMPLE function: gimple_seq gimple_omp_for_pre_body (gimple g) 13615 Return the sequence of statements to execute before the `OMP_FOR' 13616 statement `G' starts. 13617 13618 -- GIMPLE function: void gimple_omp_for_set_pre_body (gimple g, 13619 gimple_seq pre_body) 13620 Set `PRE_BODY' to be the sequence of statements to execute before 13621 the `OMP_FOR' statement `G' starts. 13622 13623 -- GIMPLE function: void gimple_omp_for_set_cond (gimple g, enum 13624 tree_code cond) 13625 Set `COND' to be the condition code for `OMP_FOR' `G'. 13626 13627 -- GIMPLE function: enum tree_code gimple_omp_for_cond (gimple g) 13628 Return the condition code associated with `OMP_FOR' `G'. 13629 13630 13631 File: gccint.info, Node: `GIMPLE_OMP_MASTER', Next: `GIMPLE_OMP_ORDERED', Prev: `GIMPLE_OMP_FOR', Up: Tuple specific accessors 13632 13633 12.7.16 `GIMPLE_OMP_MASTER' 13634 --------------------------- 13635 13636 -- GIMPLE function: gimple gimple_build_omp_master (gimple_seq body) 13637 Build a `GIMPLE_OMP_MASTER' statement. `BODY' is the sequence of 13638 statements to be executed by just the master. 13639 13640 13641 File: gccint.info, Node: `GIMPLE_OMP_ORDERED', Next: `GIMPLE_OMP_PARALLEL', Prev: `GIMPLE_OMP_MASTER', Up: Tuple specific accessors 13642 13643 12.7.17 `GIMPLE_OMP_ORDERED' 13644 ---------------------------- 13645 13646 -- GIMPLE function: gimple gimple_build_omp_ordered (gimple_seq body) 13647 Build a `GIMPLE_OMP_ORDERED' statement. 13648 13649 `BODY' is the sequence of statements inside a loop that will executed 13650 in sequence. 13651 13652 13653 File: gccint.info, Node: `GIMPLE_OMP_PARALLEL', Next: `GIMPLE_OMP_RETURN', Prev: `GIMPLE_OMP_ORDERED', Up: Tuple specific accessors 13654 13655 12.7.18 `GIMPLE_OMP_PARALLEL' 13656 ----------------------------- 13657 13658 -- GIMPLE function: gimple gimple_build_omp_parallel (gimple_seq body, 13659 tree clauses, tree child_fn, tree data_arg) 13660 Build a `GIMPLE_OMP_PARALLEL' statement. 13661 13662 `BODY' is sequence of statements which are executed in parallel. 13663 `CLAUSES', are the `OMP' parallel construct's clauses. `CHILD_FN' is 13664 the function created for the parallel threads to execute. `DATA_ARG' 13665 are the shared data argument(s). 13666 13667 -- GIMPLE function: bool gimple_omp_parallel_combined_p (gimple g) 13668 Return true if `OMP' parallel statement `G' has the 13669 `GF_OMP_PARALLEL_COMBINED' flag set. 13670 13671 -- GIMPLE function: void gimple_omp_parallel_set_combined_p (gimple g) 13672 Set the `GF_OMP_PARALLEL_COMBINED' field in `OMP' parallel 13673 statement `G'. 13674 13675 -- GIMPLE function: gimple_seq gimple_omp_body (gimple g) 13676 Return the body for the `OMP' statement `G'. 13677 13678 -- GIMPLE function: void gimple_omp_set_body (gimple g, gimple_seq 13679 body) 13680 Set `BODY' to be the body for the `OMP' statement `G'. 13681 13682 -- GIMPLE function: tree gimple_omp_parallel_clauses (gimple g) 13683 Return the clauses associated with `OMP_PARALLEL' `G'. 13684 13685 -- GIMPLE function: tree *gimple_omp_parallel_clauses_ptr (gimple g) 13686 Return a pointer to the clauses associated with `OMP_PARALLEL' `G'. 13687 13688 -- GIMPLE function: void gimple_omp_parallel_set_clauses (gimple g, 13689 tree clauses) 13690 Set `CLAUSES' to be the list of clauses associated with 13691 `OMP_PARALLEL' `G'. 13692 13693 -- GIMPLE function: tree gimple_omp_parallel_child_fn (gimple g) 13694 Return the child function used to hold the body of `OMP_PARALLEL' 13695 `G'. 13696 13697 -- GIMPLE function: tree *gimple_omp_parallel_child_fn_ptr (gimple g) 13698 Return a pointer to the child function used to hold the body of 13699 `OMP_PARALLEL' `G'. 13700 13701 -- GIMPLE function: void gimple_omp_parallel_set_child_fn (gimple g, 13702 tree child_fn) 13703 Set `CHILD_FN' to be the child function for `OMP_PARALLEL' `G'. 13704 13705 -- GIMPLE function: tree gimple_omp_parallel_data_arg (gimple g) 13706 Return the artificial argument used to send variables and values 13707 from the parent to the children threads in `OMP_PARALLEL' `G'. 13708 13709 -- GIMPLE function: tree *gimple_omp_parallel_data_arg_ptr (gimple g) 13710 Return a pointer to the data argument for `OMP_PARALLEL' `G'. 13711 13712 -- GIMPLE function: void gimple_omp_parallel_set_data_arg (gimple g, 13713 tree data_arg) 13714 Set `DATA_ARG' to be the data argument for `OMP_PARALLEL' `G'. 13715 13716 -- GIMPLE function: bool is_gimple_omp (gimple stmt) 13717 Returns true when the gimple statement `STMT' is any of the OpenMP 13718 types. 13719 13720 13721 File: gccint.info, Node: `GIMPLE_OMP_RETURN', Next: `GIMPLE_OMP_SECTION', Prev: `GIMPLE_OMP_PARALLEL', Up: Tuple specific accessors 13722 13723 12.7.19 `GIMPLE_OMP_RETURN' 13724 --------------------------- 13725 13726 -- GIMPLE function: gimple gimple_build_omp_return (bool wait_p) 13727 Build a `GIMPLE_OMP_RETURN' statement. `WAIT_P' is true if this is 13728 a non-waiting return. 13729 13730 -- GIMPLE function: void gimple_omp_return_set_nowait (gimple s) 13731 Set the nowait flag on `GIMPLE_OMP_RETURN' statement `S'. 13732 13733 -- GIMPLE function: bool gimple_omp_return_nowait_p (gimple g) 13734 Return true if `OMP' return statement `G' has the 13735 `GF_OMP_RETURN_NOWAIT' flag set. 13736 13737 13738 File: gccint.info, Node: `GIMPLE_OMP_SECTION', Next: `GIMPLE_OMP_SECTIONS', Prev: `GIMPLE_OMP_RETURN', Up: Tuple specific accessors 13739 13740 12.7.20 `GIMPLE_OMP_SECTION' 13741 ---------------------------- 13742 13743 -- GIMPLE function: gimple gimple_build_omp_section (gimple_seq body) 13744 Build a `GIMPLE_OMP_SECTION' statement for a sections statement. 13745 13746 `BODY' is the sequence of statements in the section. 13747 13748 -- GIMPLE function: bool gimple_omp_section_last_p (gimple g) 13749 Return true if `OMP' section statement `G' has the 13750 `GF_OMP_SECTION_LAST' flag set. 13751 13752 -- GIMPLE function: void gimple_omp_section_set_last (gimple g) 13753 Set the `GF_OMP_SECTION_LAST' flag on `G'. 13754 13755 13756 File: gccint.info, Node: `GIMPLE_OMP_SECTIONS', Next: `GIMPLE_OMP_SINGLE', Prev: `GIMPLE_OMP_SECTION', Up: Tuple specific accessors 13757 13758 12.7.21 `GIMPLE_OMP_SECTIONS' 13759 ----------------------------- 13760 13761 -- GIMPLE function: gimple gimple_build_omp_sections (gimple_seq body, 13762 tree clauses) 13763 Build a `GIMPLE_OMP_SECTIONS' statement. `BODY' is a sequence of 13764 section statements. `CLAUSES' are any of the `OMP' sections 13765 construct's clauses: private, firstprivate, lastprivate, 13766 reduction, and nowait. 13767 13768 -- GIMPLE function: gimple gimple_build_omp_sections_switch (void) 13769 Build a `GIMPLE_OMP_SECTIONS_SWITCH' statement. 13770 13771 -- GIMPLE function: tree gimple_omp_sections_control (gimple g) 13772 Return the control variable associated with the 13773 `GIMPLE_OMP_SECTIONS' in `G'. 13774 13775 -- GIMPLE function: tree *gimple_omp_sections_control_ptr (gimple g) 13776 Return a pointer to the clauses associated with the 13777 `GIMPLE_OMP_SECTIONS' in `G'. 13778 13779 -- GIMPLE function: void gimple_omp_sections_set_control (gimple g, 13780 tree control) 13781 Set `CONTROL' to be the set of clauses associated with the 13782 `GIMPLE_OMP_SECTIONS' in `G'. 13783 13784 -- GIMPLE function: tree gimple_omp_sections_clauses (gimple g) 13785 Return the clauses associated with `OMP_SECTIONS' `G'. 13786 13787 -- GIMPLE function: tree *gimple_omp_sections_clauses_ptr (gimple g) 13788 Return a pointer to the clauses associated with `OMP_SECTIONS' `G'. 13789 13790 -- GIMPLE function: void gimple_omp_sections_set_clauses (gimple g, 13791 tree clauses) 13792 Set `CLAUSES' to be the set of clauses associated with 13793 `OMP_SECTIONS' `G'. 13794 13795 13796 File: gccint.info, Node: `GIMPLE_OMP_SINGLE', Next: `GIMPLE_PHI', Prev: `GIMPLE_OMP_SECTIONS', Up: Tuple specific accessors 13797 13798 12.7.22 `GIMPLE_OMP_SINGLE' 13799 --------------------------- 13800 13801 -- GIMPLE function: gimple gimple_build_omp_single (gimple_seq body, 13802 tree clauses) 13803 Build a `GIMPLE_OMP_SINGLE' statement. `BODY' is the sequence of 13804 statements that will be executed once. `CLAUSES' are any of the 13805 `OMP' single construct's clauses: private, firstprivate, 13806 copyprivate, nowait. 13807 13808 -- GIMPLE function: tree gimple_omp_single_clauses (gimple g) 13809 Return the clauses associated with `OMP_SINGLE' `G'. 13810 13811 -- GIMPLE function: tree *gimple_omp_single_clauses_ptr (gimple g) 13812 Return a pointer to the clauses associated with `OMP_SINGLE' `G'. 13813 13814 -- GIMPLE function: void gimple_omp_single_set_clauses (gimple g, tree 13815 clauses) 13816 Set `CLAUSES' to be the clauses associated with `OMP_SINGLE' `G'. 13817 13818 13819 File: gccint.info, Node: `GIMPLE_PHI', Next: `GIMPLE_RESX', Prev: `GIMPLE_OMP_SINGLE', Up: Tuple specific accessors 13820 13821 12.7.23 `GIMPLE_PHI' 13822 -------------------- 13823 13824 -- GIMPLE function: gimple make_phi_node (tree var, int len) 13825 Build a `PHI' node with len argument slots for variable var. 13826 13827 -- GIMPLE function: unsigned gimple_phi_capacity (gimple g) 13828 Return the maximum number of arguments supported by `GIMPLE_PHI' 13829 `G'. 13830 13831 -- GIMPLE function: unsigned gimple_phi_num_args (gimple g) 13832 Return the number of arguments in `GIMPLE_PHI' `G'. This must 13833 always be exactly the number of incoming edges for the basic block 13834 holding `G'. 13835 13836 -- GIMPLE function: tree gimple_phi_result (gimple g) 13837 Return the `SSA' name created by `GIMPLE_PHI' `G'. 13838 13839 -- GIMPLE function: tree *gimple_phi_result_ptr (gimple g) 13840 Return a pointer to the `SSA' name created by `GIMPLE_PHI' `G'. 13841 13842 -- GIMPLE function: void gimple_phi_set_result (gimple g, tree result) 13843 Set `RESULT' to be the `SSA' name created by `GIMPLE_PHI' `G'. 13844 13845 -- GIMPLE function: struct phi_arg_d *gimple_phi_arg (gimple g, index) 13846 Return the `PHI' argument corresponding to incoming edge `INDEX' 13847 for `GIMPLE_PHI' `G'. 13848 13849 -- GIMPLE function: void gimple_phi_set_arg (gimple g, index, struct 13850 phi_arg_d * phiarg) 13851 Set `PHIARG' to be the argument corresponding to incoming edge 13852 `INDEX' for `GIMPLE_PHI' `G'. 13853 13854 13855 File: gccint.info, Node: `GIMPLE_RESX', Next: `GIMPLE_RETURN', Prev: `GIMPLE_PHI', Up: Tuple specific accessors 13856 13857 12.7.24 `GIMPLE_RESX' 13858 --------------------- 13859 13860 -- GIMPLE function: gimple gimple_build_resx (int region) 13861 Build a `GIMPLE_RESX' statement which is a statement. This 13862 statement is a placeholder for _Unwind_Resume before we know if a 13863 function call or a branch is needed. `REGION' is the exception 13864 region from which control is flowing. 13865 13866 -- GIMPLE function: int gimple_resx_region (gimple g) 13867 Return the region number for `GIMPLE_RESX' `G'. 13868 13869 -- GIMPLE function: void gimple_resx_set_region (gimple g, int region) 13870 Set `REGION' to be the region number for `GIMPLE_RESX' `G'. 13871 13872 13873 File: gccint.info, Node: `GIMPLE_RETURN', Next: `GIMPLE_SWITCH', Prev: `GIMPLE_RESX', Up: Tuple specific accessors 13874 13875 12.7.25 `GIMPLE_RETURN' 13876 ----------------------- 13877 13878 -- GIMPLE function: gimple gimple_build_return (tree retval) 13879 Build a `GIMPLE_RETURN' statement whose return value is retval. 13880 13881 -- GIMPLE function: tree gimple_return_retval (gimple g) 13882 Return the return value for `GIMPLE_RETURN' `G'. 13883 13884 -- GIMPLE function: void gimple_return_set_retval (gimple g, tree 13885 retval) 13886 Set `RETVAL' to be the return value for `GIMPLE_RETURN' `G'. 13887 13888 13889 File: gccint.info, Node: `GIMPLE_SWITCH', Next: `GIMPLE_TRY', Prev: `GIMPLE_RETURN', Up: Tuple specific accessors 13890 13891 12.7.26 `GIMPLE_SWITCH' 13892 ----------------------- 13893 13894 -- GIMPLE function: gimple gimple_build_switch ( nlabels, tree index, 13895 tree default_label, ...) 13896 Build a `GIMPLE_SWITCH' statement. `NLABELS' are the number of 13897 labels excluding the default label. The default label is passed 13898 in `DEFAULT_LABEL'. The rest of the arguments are trees 13899 representing the labels. Each label is a tree of code 13900 `CASE_LABEL_EXPR'. 13901 13902 -- GIMPLE function: gimple gimple_build_switch_vec (tree index, tree 13903 default_label, `VEC'(tree,heap) *args) 13904 This function is an alternate way of building `GIMPLE_SWITCH' 13905 statements. `INDEX' and `DEFAULT_LABEL' are as in 13906 gimple_build_switch. `ARGS' is a vector of `CASE_LABEL_EXPR' trees 13907 that contain the labels. 13908 13909 -- GIMPLE function: unsigned gimple_switch_num_labels (gimple g) 13910 Return the number of labels associated with the switch statement 13911 `G'. 13912 13913 -- GIMPLE function: void gimple_switch_set_num_labels (gimple g, 13914 unsigned nlabels) 13915 Set `NLABELS' to be the number of labels for the switch statement 13916 `G'. 13917 13918 -- GIMPLE function: tree gimple_switch_index (gimple g) 13919 Return the index variable used by the switch statement `G'. 13920 13921 -- GIMPLE function: void gimple_switch_set_index (gimple g, tree index) 13922 Set `INDEX' to be the index variable for switch statement `G'. 13923 13924 -- GIMPLE function: tree gimple_switch_label (gimple g, unsigned index) 13925 Return the label numbered `INDEX'. The default label is 0, followed 13926 by any labels in a switch statement. 13927 13928 -- GIMPLE function: void gimple_switch_set_label (gimple g, unsigned 13929 index, tree label) 13930 Set the label number `INDEX' to `LABEL'. 0 is always the default 13931 label. 13932 13933 -- GIMPLE function: tree gimple_switch_default_label (gimple g) 13934 Return the default label for a switch statement. 13935 13936 -- GIMPLE function: void gimple_switch_set_default_label (gimple g, 13937 tree label) 13938 Set the default label for a switch statement. 13939 13940 13941 File: gccint.info, Node: `GIMPLE_TRY', Next: `GIMPLE_WITH_CLEANUP_EXPR', Prev: `GIMPLE_SWITCH', Up: Tuple specific accessors 13942 13943 12.7.27 `GIMPLE_TRY' 13944 -------------------- 13945 13946 -- GIMPLE function: gimple gimple_build_try (gimple_seq eval, 13947 gimple_seq cleanup, unsigned int kind) 13948 Build a `GIMPLE_TRY' statement. `EVAL' is a sequence with the 13949 expression to evaluate. `CLEANUP' is a sequence of statements to 13950 run at clean-up time. `KIND' is the enumeration value 13951 `GIMPLE_TRY_CATCH' if this statement denotes a try/catch construct 13952 or `GIMPLE_TRY_FINALLY' if this statement denotes a try/finally 13953 construct. 13954 13955 -- GIMPLE function: enum gimple_try_flags gimple_try_kind (gimple g) 13956 Return the kind of try block represented by `GIMPLE_TRY' `G'. This 13957 is either `GIMPLE_TRY_CATCH' or `GIMPLE_TRY_FINALLY'. 13958 13959 -- GIMPLE function: bool gimple_try_catch_is_cleanup (gimple g) 13960 Return the `GIMPLE_TRY_CATCH_IS_CLEANUP' flag. 13961 13962 -- GIMPLE function: gimple_seq gimple_try_eval (gimple g) 13963 Return the sequence of statements used as the body for `GIMPLE_TRY' 13964 `G'. 13965 13966 -- GIMPLE function: gimple_seq gimple_try_cleanup (gimple g) 13967 Return the sequence of statements used as the cleanup body for 13968 `GIMPLE_TRY' `G'. 13969 13970 -- GIMPLE function: void gimple_try_set_catch_is_cleanup (gimple g, 13971 bool catch_is_cleanup) 13972 Set the `GIMPLE_TRY_CATCH_IS_CLEANUP' flag. 13973 13974 -- GIMPLE function: void gimple_try_set_eval (gimple g, gimple_seq 13975 eval) 13976 Set `EVAL' to be the sequence of statements to use as the body for 13977 `GIMPLE_TRY' `G'. 13978 13979 -- GIMPLE function: void gimple_try_set_cleanup (gimple g, gimple_seq 13980 cleanup) 13981 Set `CLEANUP' to be the sequence of statements to use as the 13982 cleanup body for `GIMPLE_TRY' `G'. 13983 13984 13985 File: gccint.info, Node: `GIMPLE_WITH_CLEANUP_EXPR', Prev: `GIMPLE_TRY', Up: Tuple specific accessors 13986 13987 12.7.28 `GIMPLE_WITH_CLEANUP_EXPR' 13988 ---------------------------------- 13989 13990 -- GIMPLE function: gimple gimple_build_wce (gimple_seq cleanup) 13991 Build a `GIMPLE_WITH_CLEANUP_EXPR' statement. `CLEANUP' is the 13992 clean-up expression. 13993 13994 -- GIMPLE function: gimple_seq gimple_wce_cleanup (gimple g) 13995 Return the cleanup sequence for cleanup statement `G'. 13996 13997 -- GIMPLE function: void gimple_wce_set_cleanup (gimple g, gimple_seq 13998 cleanup) 13999 Set `CLEANUP' to be the cleanup sequence for `G'. 14000 14001 -- GIMPLE function: bool gimple_wce_cleanup_eh_only (gimple g) 14002 Return the `CLEANUP_EH_ONLY' flag for a `WCE' tuple. 14003 14004 -- GIMPLE function: void gimple_wce_set_cleanup_eh_only (gimple g, 14005 bool eh_only_p) 14006 Set the `CLEANUP_EH_ONLY' flag for a `WCE' tuple. 14007 14008 14009 File: gccint.info, Node: GIMPLE sequences, Next: Sequence iterators, Prev: Tuple specific accessors, Up: GIMPLE 14010 14011 12.8 GIMPLE sequences 14012 ===================== 14013 14014 GIMPLE sequences are the tuple equivalent of `STATEMENT_LIST''s used in 14015 `GENERIC'. They are used to chain statements together, and when used 14016 in conjunction with sequence iterators, provide a framework for 14017 iterating through statements. 14018 14019 GIMPLE sequences are of type struct `gimple_sequence', but are more 14020 commonly passed by reference to functions dealing with sequences. The 14021 type for a sequence pointer is `gimple_seq' which is the same as struct 14022 `gimple_sequence' *. When declaring a local sequence, you can define a 14023 local variable of type struct `gimple_sequence'. When declaring a 14024 sequence allocated on the garbage collected heap, use the function 14025 `gimple_seq_alloc' documented below. 14026 14027 There are convenience functions for iterating through sequences in the 14028 section entitled Sequence Iterators. 14029 14030 Below is a list of functions to manipulate and query sequences. 14031 14032 -- GIMPLE function: void gimple_seq_add_stmt (gimple_seq *seq, gimple 14033 g) 14034 Link a gimple statement to the end of the sequence *`SEQ' if `G' is 14035 not `NULL'. If *`SEQ' is `NULL', allocate a sequence before 14036 linking. 14037 14038 -- GIMPLE function: void gimple_seq_add_seq (gimple_seq *dest, 14039 gimple_seq src) 14040 Append sequence `SRC' to the end of sequence *`DEST' if `SRC' is 14041 not `NULL'. If *`DEST' is `NULL', allocate a new sequence before 14042 appending. 14043 14044 -- GIMPLE function: gimple_seq gimple_seq_deep_copy (gimple_seq src) 14045 Perform a deep copy of sequence `SRC' and return the result. 14046 14047 -- GIMPLE function: gimple_seq gimple_seq_reverse (gimple_seq seq) 14048 Reverse the order of the statements in the sequence `SEQ'. Return 14049 `SEQ'. 14050 14051 -- GIMPLE function: gimple gimple_seq_first (gimple_seq s) 14052 Return the first statement in sequence `S'. 14053 14054 -- GIMPLE function: gimple gimple_seq_last (gimple_seq s) 14055 Return the last statement in sequence `S'. 14056 14057 -- GIMPLE function: void gimple_seq_set_last (gimple_seq s, gimple 14058 last) 14059 Set the last statement in sequence `S' to the statement in `LAST'. 14060 14061 -- GIMPLE function: void gimple_seq_set_first (gimple_seq s, gimple 14062 first) 14063 Set the first statement in sequence `S' to the statement in 14064 `FIRST'. 14065 14066 -- GIMPLE function: void gimple_seq_init (gimple_seq s) 14067 Initialize sequence `S' to an empty sequence. 14068 14069 -- GIMPLE function: gimple_seq gimple_seq_alloc (void) 14070 Allocate a new sequence in the garbage collected store and return 14071 it. 14072 14073 -- GIMPLE function: void gimple_seq_copy (gimple_seq dest, gimple_seq 14074 src) 14075 Copy the sequence `SRC' into the sequence `DEST'. 14076 14077 -- GIMPLE function: bool gimple_seq_empty_p (gimple_seq s) 14078 Return true if the sequence `S' is empty. 14079 14080 -- GIMPLE function: gimple_seq bb_seq (basic_block bb) 14081 Returns the sequence of statements in `BB'. 14082 14083 -- GIMPLE function: void set_bb_seq (basic_block bb, gimple_seq seq) 14084 Sets the sequence of statements in `BB' to `SEQ'. 14085 14086 -- GIMPLE function: bool gimple_seq_singleton_p (gimple_seq seq) 14087 Determine whether `SEQ' contains exactly one statement. 14088 14089 14090 File: gccint.info, Node: Sequence iterators, Next: Adding a new GIMPLE statement code, Prev: GIMPLE sequences, Up: GIMPLE 14091 14092 12.9 Sequence iterators 14093 ======================= 14094 14095 Sequence iterators are convenience constructs for iterating through 14096 statements in a sequence. Given a sequence `SEQ', here is a typical 14097 use of gimple sequence iterators: 14098 14099 gimple_stmt_iterator gsi; 14100 14101 for (gsi = gsi_start (seq); !gsi_end_p (gsi); gsi_next (&gsi)) 14102 { 14103 gimple g = gsi_stmt (gsi); 14104 /* Do something with gimple statement `G'. */ 14105 } 14106 14107 Backward iterations are possible: 14108 14109 for (gsi = gsi_last (seq); !gsi_end_p (gsi); gsi_prev (&gsi)) 14110 14111 Forward and backward iterations on basic blocks are possible with 14112 `gsi_start_bb' and `gsi_last_bb'. 14113 14114 In the documentation below we sometimes refer to enum 14115 `gsi_iterator_update'. The valid options for this enumeration are: 14116 14117 * `GSI_NEW_STMT' Only valid when a single statement is added. Move 14118 the iterator to it. 14119 14120 * `GSI_SAME_STMT' Leave the iterator at the same statement. 14121 14122 * `GSI_CONTINUE_LINKING' Move iterator to whatever position is 14123 suitable for linking other statements in the same direction. 14124 14125 Below is a list of the functions used to manipulate and use statement 14126 iterators. 14127 14128 -- GIMPLE function: gimple_stmt_iterator gsi_start (gimple_seq seq) 14129 Return a new iterator pointing to the sequence `SEQ''s first 14130 statement. If `SEQ' is empty, the iterator's basic block is 14131 `NULL'. Use `gsi_start_bb' instead when the iterator needs to 14132 always have the correct basic block set. 14133 14134 -- GIMPLE function: gimple_stmt_iterator gsi_start_bb (basic_block bb) 14135 Return a new iterator pointing to the first statement in basic 14136 block `BB'. 14137 14138 -- GIMPLE function: gimple_stmt_iterator gsi_last (gimple_seq seq) 14139 Return a new iterator initially pointing to the last statement of 14140 sequence `SEQ'. If `SEQ' is empty, the iterator's basic block is 14141 `NULL'. Use `gsi_last_bb' instead when the iterator needs to 14142 always have the correct basic block set. 14143 14144 -- GIMPLE function: gimple_stmt_iterator gsi_last_bb (basic_block bb) 14145 Return a new iterator pointing to the last statement in basic 14146 block `BB'. 14147 14148 -- GIMPLE function: bool gsi_end_p (gimple_stmt_iterator i) 14149 Return `TRUE' if at the end of `I'. 14150 14151 -- GIMPLE function: bool gsi_one_before_end_p (gimple_stmt_iterator i) 14152 Return `TRUE' if we're one statement before the end of `I'. 14153 14154 -- GIMPLE function: void gsi_next (gimple_stmt_iterator *i) 14155 Advance the iterator to the next gimple statement. 14156 14157 -- GIMPLE function: void gsi_prev (gimple_stmt_iterator *i) 14158 Advance the iterator to the previous gimple statement. 14159 14160 -- GIMPLE function: gimple gsi_stmt (gimple_stmt_iterator i) 14161 Return the current stmt. 14162 14163 -- GIMPLE function: gimple_stmt_iterator gsi_after_labels (basic_block 14164 bb) 14165 Return a block statement iterator that points to the first 14166 non-label statement in block `BB'. 14167 14168 -- GIMPLE function: gimple *gsi_stmt_ptr (gimple_stmt_iterator *i) 14169 Return a pointer to the current stmt. 14170 14171 -- GIMPLE function: basic_block gsi_bb (gimple_stmt_iterator i) 14172 Return the basic block associated with this iterator. 14173 14174 -- GIMPLE function: gimple_seq gsi_seq (gimple_stmt_iterator i) 14175 Return the sequence associated with this iterator. 14176 14177 -- GIMPLE function: void gsi_remove (gimple_stmt_iterator *i, bool 14178 remove_eh_info) 14179 Remove the current stmt from the sequence. The iterator is 14180 updated to point to the next statement. When `REMOVE_EH_INFO' is 14181 true we remove the statement pointed to by iterator `I' from the 14182 `EH' tables. Otherwise we do not modify the `EH' tables. 14183 Generally, `REMOVE_EH_INFO' should be true when the statement is 14184 going to be removed from the `IL' and not reinserted elsewhere. 14185 14186 -- GIMPLE function: void gsi_link_seq_before (gimple_stmt_iterator *i, 14187 gimple_seq seq, enum gsi_iterator_update mode) 14188 Links the sequence of statements `SEQ' before the statement pointed 14189 by iterator `I'. `MODE' indicates what to do with the iterator 14190 after insertion (see `enum gsi_iterator_update' above). 14191 14192 -- GIMPLE function: void gsi_link_before (gimple_stmt_iterator *i, 14193 gimple g, enum gsi_iterator_update mode) 14194 Links statement `G' before the statement pointed-to by iterator 14195 `I'. Updates iterator `I' according to `MODE'. 14196 14197 -- GIMPLE function: void gsi_link_seq_after (gimple_stmt_iterator *i, 14198 gimple_seq seq, enum gsi_iterator_update mode) 14199 Links sequence `SEQ' after the statement pointed-to by iterator 14200 `I'. `MODE' is as in `gsi_insert_after'. 14201 14202 -- GIMPLE function: void gsi_link_after (gimple_stmt_iterator *i, 14203 gimple g, enum gsi_iterator_update mode) 14204 Links statement `G' after the statement pointed-to by iterator `I'. 14205 `MODE' is as in `gsi_insert_after'. 14206 14207 -- GIMPLE function: gimple_seq gsi_split_seq_after 14208 (gimple_stmt_iterator i) 14209 Move all statements in the sequence after `I' to a new sequence. 14210 Return this new sequence. 14211 14212 -- GIMPLE function: gimple_seq gsi_split_seq_before 14213 (gimple_stmt_iterator *i) 14214 Move all statements in the sequence before `I' to a new sequence. 14215 Return this new sequence. 14216 14217 -- GIMPLE function: void gsi_replace (gimple_stmt_iterator *i, gimple 14218 stmt, bool update_eh_info) 14219 Replace the statement pointed-to by `I' to `STMT'. If 14220 `UPDATE_EH_INFO' is true, the exception handling information of 14221 the original statement is moved to the new statement. 14222 14223 -- GIMPLE function: void gsi_insert_before (gimple_stmt_iterator *i, 14224 gimple stmt, enum gsi_iterator_update mode) 14225 Insert statement `STMT' before the statement pointed-to by iterator 14226 `I', update `STMT''s basic block and scan it for new operands. 14227 `MODE' specifies how to update iterator `I' after insertion (see 14228 enum `gsi_iterator_update'). 14229 14230 -- GIMPLE function: void gsi_insert_seq_before (gimple_stmt_iterator 14231 *i, gimple_seq seq, enum gsi_iterator_update mode) 14232 Like `gsi_insert_before', but for all the statements in `SEQ'. 14233 14234 -- GIMPLE function: void gsi_insert_after (gimple_stmt_iterator *i, 14235 gimple stmt, enum gsi_iterator_update mode) 14236 Insert statement `STMT' after the statement pointed-to by iterator 14237 `I', update `STMT''s basic block and scan it for new operands. 14238 `MODE' specifies how to update iterator `I' after insertion (see 14239 enum `gsi_iterator_update'). 14240 14241 -- GIMPLE function: void gsi_insert_seq_after (gimple_stmt_iterator 14242 *i, gimple_seq seq, enum gsi_iterator_update mode) 14243 Like `gsi_insert_after', but for all the statements in `SEQ'. 14244 14245 -- GIMPLE function: gimple_stmt_iterator gsi_for_stmt (gimple stmt) 14246 Finds iterator for `STMT'. 14247 14248 -- GIMPLE function: void gsi_move_after (gimple_stmt_iterator *from, 14249 gimple_stmt_iterator *to) 14250 Move the statement at `FROM' so it comes right after the statement 14251 at `TO'. 14252 14253 -- GIMPLE function: void gsi_move_before (gimple_stmt_iterator *from, 14254 gimple_stmt_iterator *to) 14255 Move the statement at `FROM' so it comes right before the statement 14256 at `TO'. 14257 14258 -- GIMPLE function: void gsi_move_to_bb_end (gimple_stmt_iterator 14259 *from, basic_block bb) 14260 Move the statement at `FROM' to the end of basic block `BB'. 14261 14262 -- GIMPLE function: void gsi_insert_on_edge (edge e, gimple stmt) 14263 Add `STMT' to the pending list of edge `E'. No actual insertion is 14264 made until a call to `gsi_commit_edge_inserts'() is made. 14265 14266 -- GIMPLE function: void gsi_insert_seq_on_edge (edge e, gimple_seq 14267 seq) 14268 Add the sequence of statements in `SEQ' to the pending list of edge 14269 `E'. No actual insertion is made until a call to 14270 `gsi_commit_edge_inserts'() is made. 14271 14272 -- GIMPLE function: basic_block gsi_insert_on_edge_immediate (edge e, 14273 gimple stmt) 14274 Similar to `gsi_insert_on_edge'+`gsi_commit_edge_inserts'. If a 14275 new block has to be created, it is returned. 14276 14277 -- GIMPLE function: void gsi_commit_one_edge_insert (edge e, 14278 basic_block *new_bb) 14279 Commit insertions pending at edge `E'. If a new block is created, 14280 set `NEW_BB' to this block, otherwise set it to `NULL'. 14281 14282 -- GIMPLE function: void gsi_commit_edge_inserts (void) 14283 This routine will commit all pending edge insertions, creating any 14284 new basic blocks which are necessary. 14285 14286 14287 File: gccint.info, Node: Adding a new GIMPLE statement code, Next: Statement and operand traversals, Prev: Sequence iterators, Up: GIMPLE 14288 14289 12.10 Adding a new GIMPLE statement code 14290 ======================================== 14291 14292 The first step in adding a new GIMPLE statement code, is modifying the 14293 file `gimple.def', which contains all the GIMPLE codes. Then you must 14294 add a corresponding structure, and an entry in `union 14295 gimple_statement_d', both of which are located in `gimple.h'. This in 14296 turn, will require you to add a corresponding `GTY' tag in 14297 `gsstruct.def', and code to handle this tag in `gss_for_code' which is 14298 located in `gimple.c'. 14299 14300 In order for the garbage collector to know the size of the structure 14301 you created in `gimple.h', you need to add a case to handle your new 14302 GIMPLE statement in `gimple_size' which is located in `gimple.c'. 14303 14304 You will probably want to create a function to build the new gimple 14305 statement in `gimple.c'. The function should be called 14306 `gimple_build_<`NEW_TUPLE_NAME'>', and should return the new tuple of 14307 type gimple. 14308 14309 If your new statement requires accessors for any members or operands 14310 it may have, put simple inline accessors in `gimple.h' and any 14311 non-trivial accessors in `gimple.c' with a corresponding prototype in 14312 `gimple.h'. 14313 14314 14315 File: gccint.info, Node: Statement and operand traversals, Prev: Adding a new GIMPLE statement code, Up: GIMPLE 14316 14317 12.11 Statement and operand traversals 14318 ====================================== 14319 14320 There are two functions available for walking statements and sequences: 14321 `walk_gimple_stmt' and `walk_gimple_seq', accordingly, and a third 14322 function for walking the operands in a statement: `walk_gimple_op'. 14323 14324 -- GIMPLE function: tree walk_gimple_stmt (gimple_stmt_iterator *gsi, 14325 walk_stmt_fn callback_stmt, walk_tree_fn callback_op, struct 14326 walk_stmt_info *wi) 14327 This function is used to walk the current statement in `GSI', 14328 optionally using traversal state stored in `WI'. If `WI' is 14329 `NULL', no state is kept during the traversal. 14330 14331 The callback `CALLBACK_STMT' is called. If `CALLBACK_STMT' returns 14332 true, it means that the callback function has handled all the 14333 operands of the statement and it is not necessary to walk its 14334 operands. 14335 14336 If `CALLBACK_STMT' is `NULL' or it returns false, `CALLBACK_OP' is 14337 called on each operand of the statement via `walk_gimple_op'. If 14338 `walk_gimple_op' returns non-`NULL' for any operand, the remaining 14339 operands are not scanned. 14340 14341 The return value is that returned by the last call to 14342 `walk_gimple_op', or `NULL_TREE' if no `CALLBACK_OP' is specified. 14343 14344 -- GIMPLE function: tree walk_gimple_op (gimple stmt, walk_tree_fn 14345 callback_op, struct walk_stmt_info *wi) 14346 Use this function to walk the operands of statement `STMT'. Every 14347 operand is walked via `walk_tree' with optional state information 14348 in `WI'. 14349 14350 `CALLBACK_OP' is called on each operand of `STMT' via `walk_tree'. 14351 Additional parameters to `walk_tree' must be stored in `WI'. For 14352 each operand `OP', `walk_tree' is called as: 14353 14354 walk_tree (&`OP', `CALLBACK_OP', `WI', `WI'- `PSET') 14355 14356 If `CALLBACK_OP' returns non-`NULL' for an operand, the remaining 14357 operands are not scanned. The return value is that returned by 14358 the last call to `walk_tree', or `NULL_TREE' if no `CALLBACK_OP' is 14359 specified. 14360 14361 -- GIMPLE function: tree walk_gimple_seq (gimple_seq seq, walk_stmt_fn 14362 callback_stmt, walk_tree_fn callback_op, struct 14363 walk_stmt_info *wi) 14364 This function walks all the statements in the sequence `SEQ' 14365 calling `walk_gimple_stmt' on each one. `WI' is as in 14366 `walk_gimple_stmt'. If `walk_gimple_stmt' returns non-`NULL', the 14367 walk is stopped and the value returned. Otherwise, all the 14368 statements are walked and `NULL_TREE' returned. 14369 14370 14371 File: gccint.info, Node: Tree SSA, Next: Control Flow, Prev: GIMPLE, Up: Top 14372 14373 13 Analysis and Optimization of GIMPLE tuples 14374 ********************************************* 14375 14376 GCC uses three main intermediate languages to represent the program 14377 during compilation: GENERIC, GIMPLE and RTL. GENERIC is a 14378 language-independent representation generated by each front end. It is 14379 used to serve as an interface between the parser and optimizer. 14380 GENERIC is a common representation that is able to represent programs 14381 written in all the languages supported by GCC. 14382 14383 GIMPLE and RTL are used to optimize the program. GIMPLE is used for 14384 target and language independent optimizations (e.g., inlining, constant 14385 propagation, tail call elimination, redundancy elimination, etc). Much 14386 like GENERIC, GIMPLE is a language independent, tree based 14387 representation. However, it differs from GENERIC in that the GIMPLE 14388 grammar is more restrictive: expressions contain no more than 3 14389 operands (except function calls), it has no control flow structures and 14390 expressions with side-effects are only allowed on the right hand side 14391 of assignments. See the chapter describing GENERIC and GIMPLE for more 14392 details. 14393 14394 This chapter describes the data structures and functions used in the 14395 GIMPLE optimizers (also known as "tree optimizers" or "middle end"). 14396 In particular, it focuses on all the macros, data structures, functions 14397 and programming constructs needed to implement optimization passes for 14398 GIMPLE. 14399 14400 * Menu: 14401 14402 * Annotations:: Attributes for variables. 14403 * SSA Operands:: SSA names referenced by GIMPLE statements. 14404 * SSA:: Static Single Assignment representation. 14405 * Alias analysis:: Representing aliased loads and stores. 14406 14407 14408 File: gccint.info, Node: Annotations, Next: SSA Operands, Up: Tree SSA 14409 14410 13.1 Annotations 14411 ================ 14412 14413 The optimizers need to associate attributes with variables during the 14414 optimization process. For instance, we need to know whether a variable 14415 has aliases. All these attributes are stored in data structures called 14416 annotations which are then linked to the field `ann' in `struct 14417 tree_common'. 14418 14419 Presently, we define annotations for variables (`var_ann_t'). 14420 Annotations are defined and documented in `tree-flow.h'. 14421 14422 14423 File: gccint.info, Node: SSA Operands, Next: SSA, Prev: Annotations, Up: Tree SSA 14424 14425 13.2 SSA Operands 14426 ================= 14427 14428 Almost every GIMPLE statement will contain a reference to a variable or 14429 memory location. Since statements come in different shapes and sizes, 14430 their operands are going to be located at various spots inside the 14431 statement's tree. To facilitate access to the statement's operands, 14432 they are organized into lists associated inside each statement's 14433 annotation. Each element in an operand list is a pointer to a 14434 `VAR_DECL', `PARM_DECL' or `SSA_NAME' tree node. This provides a very 14435 convenient way of examining and replacing operands. 14436 14437 Data flow analysis and optimization is done on all tree nodes 14438 representing variables. Any node for which `SSA_VAR_P' returns nonzero 14439 is considered when scanning statement operands. However, not all 14440 `SSA_VAR_P' variables are processed in the same way. For the purposes 14441 of optimization, we need to distinguish between references to local 14442 scalar variables and references to globals, statics, structures, 14443 arrays, aliased variables, etc. The reason is simple, the compiler can 14444 gather complete data flow information for a local scalar. On the other 14445 hand, a global variable may be modified by a function call, it may not 14446 be possible to keep track of all the elements of an array or the fields 14447 of a structure, etc. 14448 14449 The operand scanner gathers two kinds of operands: "real" and 14450 "virtual". An operand for which `is_gimple_reg' returns true is 14451 considered real, otherwise it is a virtual operand. We also 14452 distinguish between uses and definitions. An operand is used if its 14453 value is loaded by the statement (e.g., the operand at the RHS of an 14454 assignment). If the statement assigns a new value to the operand, the 14455 operand is considered a definition (e.g., the operand at the LHS of an 14456 assignment). 14457 14458 Virtual and real operands also have very different data flow 14459 properties. Real operands are unambiguous references to the full 14460 object that they represent. For instance, given 14461 14462 { 14463 int a, b; 14464 a = b 14465 } 14466 14467 Since `a' and `b' are non-aliased locals, the statement `a = b' will 14468 have one real definition and one real use because variable `b' is 14469 completely modified with the contents of variable `a'. Real definition 14470 are also known as "killing definitions". Similarly, the use of `a' 14471 reads all its bits. 14472 14473 In contrast, virtual operands are used with variables that can have a 14474 partial or ambiguous reference. This includes structures, arrays, 14475 globals, and aliased variables. In these cases, we have two types of 14476 definitions. For globals, structures, and arrays, we can determine from 14477 a statement whether a variable of these types has a killing definition. 14478 If the variable does, then the statement is marked as having a "must 14479 definition" of that variable. However, if a statement is only defining 14480 a part of the variable (i.e. a field in a structure), or if we know 14481 that a statement might define the variable but we cannot say for sure, 14482 then we mark that statement as having a "may definition". For 14483 instance, given 14484 14485 { 14486 int a, b, *p; 14487 14488 if (...) 14489 p = &a; 14490 else 14491 p = &b; 14492 *p = 5; 14493 return *p; 14494 } 14495 14496 The assignment `*p = 5' may be a definition of `a' or `b'. If we 14497 cannot determine statically where `p' is pointing to at the time of the 14498 store operation, we create virtual definitions to mark that statement 14499 as a potential definition site for `a' and `b'. Memory loads are 14500 similarly marked with virtual use operands. Virtual operands are shown 14501 in tree dumps right before the statement that contains them. To 14502 request a tree dump with virtual operands, use the `-vops' option to 14503 `-fdump-tree': 14504 14505 { 14506 int a, b, *p; 14507 14508 if (...) 14509 p = &a; 14510 else 14511 p = &b; 14512 # a = VDEF <a> 14513 # b = VDEF <b> 14514 *p = 5; 14515 14516 # VUSE <a> 14517 # VUSE <b> 14518 return *p; 14519 } 14520 14521 Notice that `VDEF' operands have two copies of the referenced 14522 variable. This indicates that this is not a killing definition of that 14523 variable. In this case we refer to it as a "may definition" or 14524 "aliased store". The presence of the second copy of the variable in 14525 the `VDEF' operand will become important when the function is converted 14526 into SSA form. This will be used to link all the non-killing 14527 definitions to prevent optimizations from making incorrect assumptions 14528 about them. 14529 14530 Operands are updated as soon as the statement is finished via a call 14531 to `update_stmt'. If statement elements are changed via `SET_USE' or 14532 `SET_DEF', then no further action is required (i.e., those macros take 14533 care of updating the statement). If changes are made by manipulating 14534 the statement's tree directly, then a call must be made to 14535 `update_stmt' when complete. Calling one of the `bsi_insert' routines 14536 or `bsi_replace' performs an implicit call to `update_stmt'. 14537 14538 13.2.1 Operand Iterators And Access Routines 14539 -------------------------------------------- 14540 14541 Operands are collected by `tree-ssa-operands.c'. They are stored 14542 inside each statement's annotation and can be accessed through either 14543 the operand iterators or an access routine. 14544 14545 The following access routines are available for examining operands: 14546 14547 1. `SINGLE_SSA_{USE,DEF,TREE}_OPERAND': These accessors will return 14548 NULL unless there is exactly one operand matching the specified 14549 flags. If there is exactly one operand, the operand is returned 14550 as either a `tree', `def_operand_p', or `use_operand_p'. 14551 14552 tree t = SINGLE_SSA_TREE_OPERAND (stmt, flags); 14553 use_operand_p u = SINGLE_SSA_USE_OPERAND (stmt, SSA_ALL_VIRTUAL_USES); 14554 def_operand_p d = SINGLE_SSA_DEF_OPERAND (stmt, SSA_OP_ALL_DEFS); 14555 14556 2. `ZERO_SSA_OPERANDS': This macro returns true if there are no 14557 operands matching the specified flags. 14558 14559 if (ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS)) 14560 return; 14561 14562 3. `NUM_SSA_OPERANDS': This macro Returns the number of operands 14563 matching 'flags'. This actually executes a loop to perform the 14564 count, so only use this if it is really needed. 14565 14566 int count = NUM_SSA_OPERANDS (stmt, flags) 14567 14568 If you wish to iterate over some or all operands, use the 14569 `FOR_EACH_SSA_{USE,DEF,TREE}_OPERAND' iterator. For example, to print 14570 all the operands for a statement: 14571 14572 void 14573 print_ops (tree stmt) 14574 { 14575 ssa_op_iter; 14576 tree var; 14577 14578 FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_ALL_OPERANDS) 14579 print_generic_expr (stderr, var, TDF_SLIM); 14580 } 14581 14582 How to choose the appropriate iterator: 14583 14584 1. Determine whether you are need to see the operand pointers, or 14585 just the trees, and choose the appropriate macro: 14586 14587 Need Macro: 14588 ---- ------- 14589 use_operand_p FOR_EACH_SSA_USE_OPERAND 14590 def_operand_p FOR_EACH_SSA_DEF_OPERAND 14591 tree FOR_EACH_SSA_TREE_OPERAND 14592 14593 2. You need to declare a variable of the type you are interested in, 14594 and an ssa_op_iter structure which serves as the loop controlling 14595 variable. 14596 14597 3. Determine which operands you wish to use, and specify the flags of 14598 those you are interested in. They are documented in 14599 `tree-ssa-operands.h': 14600 14601 #define SSA_OP_USE 0x01 /* Real USE operands. */ 14602 #define SSA_OP_DEF 0x02 /* Real DEF operands. */ 14603 #define SSA_OP_VUSE 0x04 /* VUSE operands. */ 14604 #define SSA_OP_VMAYUSE 0x08 /* USE portion of VDEFS. */ 14605 #define SSA_OP_VDEF 0x10 /* DEF portion of VDEFS. */ 14606 14607 /* These are commonly grouped operand flags. */ 14608 #define SSA_OP_VIRTUAL_USES (SSA_OP_VUSE | SSA_OP_VMAYUSE) 14609 #define SSA_OP_VIRTUAL_DEFS (SSA_OP_VDEF) 14610 #define SSA_OP_ALL_USES (SSA_OP_VIRTUAL_USES | SSA_OP_USE) 14611 #define SSA_OP_ALL_DEFS (SSA_OP_VIRTUAL_DEFS | SSA_OP_DEF) 14612 #define SSA_OP_ALL_OPERANDS (SSA_OP_ALL_USES | SSA_OP_ALL_DEFS) 14613 14614 So if you want to look at the use pointers for all the `USE' and 14615 `VUSE' operands, you would do something like: 14616 14617 use_operand_p use_p; 14618 ssa_op_iter iter; 14619 14620 FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, (SSA_OP_USE | SSA_OP_VUSE)) 14621 { 14622 process_use_ptr (use_p); 14623 } 14624 14625 The `TREE' macro is basically the same as the `USE' and `DEF' macros, 14626 only with the use or def dereferenced via `USE_FROM_PTR (use_p)' and 14627 `DEF_FROM_PTR (def_p)'. Since we aren't using operand pointers, use 14628 and defs flags can be mixed. 14629 14630 tree var; 14631 ssa_op_iter iter; 14632 14633 FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_VUSE) 14634 { 14635 print_generic_expr (stderr, var, TDF_SLIM); 14636 } 14637 14638 `VDEF's are broken into two flags, one for the `DEF' portion 14639 (`SSA_OP_VDEF') and one for the USE portion (`SSA_OP_VMAYUSE'). If all 14640 you want to look at are the `VDEF's together, there is a fourth 14641 iterator macro for this, which returns both a def_operand_p and a 14642 use_operand_p for each `VDEF' in the statement. Note that you don't 14643 need any flags for this one. 14644 14645 use_operand_p use_p; 14646 def_operand_p def_p; 14647 ssa_op_iter iter; 14648 14649 FOR_EACH_SSA_MAYDEF_OPERAND (def_p, use_p, stmt, iter) 14650 { 14651 my_code; 14652 } 14653 14654 There are many examples in the code as well, as well as the 14655 documentation in `tree-ssa-operands.h'. 14656 14657 There are also a couple of variants on the stmt iterators regarding PHI 14658 nodes. 14659 14660 `FOR_EACH_PHI_ARG' Works exactly like `FOR_EACH_SSA_USE_OPERAND', 14661 except it works over `PHI' arguments instead of statement operands. 14662 14663 /* Look at every virtual PHI use. */ 14664 FOR_EACH_PHI_ARG (use_p, phi_stmt, iter, SSA_OP_VIRTUAL_USES) 14665 { 14666 my_code; 14667 } 14668 14669 /* Look at every real PHI use. */ 14670 FOR_EACH_PHI_ARG (use_p, phi_stmt, iter, SSA_OP_USES) 14671 my_code; 14672 14673 /* Look at every PHI use. */ 14674 FOR_EACH_PHI_ARG (use_p, phi_stmt, iter, SSA_OP_ALL_USES) 14675 my_code; 14676 14677 `FOR_EACH_PHI_OR_STMT_{USE,DEF}' works exactly like 14678 `FOR_EACH_SSA_{USE,DEF}_OPERAND', except it will function on either a 14679 statement or a `PHI' node. These should be used when it is appropriate 14680 but they are not quite as efficient as the individual `FOR_EACH_PHI' 14681 and `FOR_EACH_SSA' routines. 14682 14683 FOR_EACH_PHI_OR_STMT_USE (use_operand_p, stmt, iter, flags) 14684 { 14685 my_code; 14686 } 14687 14688 FOR_EACH_PHI_OR_STMT_DEF (def_operand_p, phi, iter, flags) 14689 { 14690 my_code; 14691 } 14692 14693 13.2.2 Immediate Uses 14694 --------------------- 14695 14696 Immediate use information is now always available. Using the immediate 14697 use iterators, you may examine every use of any `SSA_NAME'. For 14698 instance, to change each use of `ssa_var' to `ssa_var2' and call 14699 fold_stmt on each stmt after that is done: 14700 14701 use_operand_p imm_use_p; 14702 imm_use_iterator iterator; 14703 tree ssa_var, stmt; 14704 14705 14706 FOR_EACH_IMM_USE_STMT (stmt, iterator, ssa_var) 14707 { 14708 FOR_EACH_IMM_USE_ON_STMT (imm_use_p, iterator) 14709 SET_USE (imm_use_p, ssa_var_2); 14710 fold_stmt (stmt); 14711 } 14712 14713 There are 2 iterators which can be used. `FOR_EACH_IMM_USE_FAST' is 14714 used when the immediate uses are not changed, i.e., you are looking at 14715 the uses, but not setting them. 14716 14717 If they do get changed, then care must be taken that things are not 14718 changed under the iterators, so use the `FOR_EACH_IMM_USE_STMT' and 14719 `FOR_EACH_IMM_USE_ON_STMT' iterators. They attempt to preserve the 14720 sanity of the use list by moving all the uses for a statement into a 14721 controlled position, and then iterating over those uses. Then the 14722 optimization can manipulate the stmt when all the uses have been 14723 processed. This is a little slower than the FAST version since it adds 14724 a placeholder element and must sort through the list a bit for each 14725 statement. This placeholder element must be also be removed if the 14726 loop is terminated early. The macro `BREAK_FROM_IMM_USE_SAFE' is 14727 provided to do this : 14728 14729 FOR_EACH_IMM_USE_STMT (stmt, iterator, ssa_var) 14730 { 14731 if (stmt == last_stmt) 14732 BREAK_FROM_SAFE_IMM_USE (iter); 14733 14734 FOR_EACH_IMM_USE_ON_STMT (imm_use_p, iterator) 14735 SET_USE (imm_use_p, ssa_var_2); 14736 fold_stmt (stmt); 14737 } 14738 14739 There are checks in `verify_ssa' which verify that the immediate use 14740 list is up to date, as well as checking that an optimization didn't 14741 break from the loop without using this macro. It is safe to simply 14742 'break'; from a `FOR_EACH_IMM_USE_FAST' traverse. 14743 14744 Some useful functions and macros: 14745 1. `has_zero_uses (ssa_var)' : Returns true if there are no uses of 14746 `ssa_var'. 14747 14748 2. `has_single_use (ssa_var)' : Returns true if there is only a 14749 single use of `ssa_var'. 14750 14751 3. `single_imm_use (ssa_var, use_operand_p *ptr, tree *stmt)' : 14752 Returns true if there is only a single use of `ssa_var', and also 14753 returns the use pointer and statement it occurs in, in the second 14754 and third parameters. 14755 14756 4. `num_imm_uses (ssa_var)' : Returns the number of immediate uses of 14757 `ssa_var'. It is better not to use this if possible since it simply 14758 utilizes a loop to count the uses. 14759 14760 5. `PHI_ARG_INDEX_FROM_USE (use_p)' : Given a use within a `PHI' 14761 node, return the index number for the use. An assert is triggered 14762 if the use isn't located in a `PHI' node. 14763 14764 6. `USE_STMT (use_p)' : Return the statement a use occurs in. 14765 14766 Note that uses are not put into an immediate use list until their 14767 statement is actually inserted into the instruction stream via a 14768 `bsi_*' routine. 14769 14770 It is also still possible to utilize lazy updating of statements, but 14771 this should be used only when absolutely required. Both alias analysis 14772 and the dominator optimizations currently do this. 14773 14774 When lazy updating is being used, the immediate use information is out 14775 of date and cannot be used reliably. Lazy updating is achieved by 14776 simply marking statements modified via calls to `mark_stmt_modified' 14777 instead of `update_stmt'. When lazy updating is no longer required, 14778 all the modified statements must have `update_stmt' called in order to 14779 bring them up to date. This must be done before the optimization is 14780 finished, or `verify_ssa' will trigger an abort. 14781 14782 This is done with a simple loop over the instruction stream: 14783 block_stmt_iterator bsi; 14784 basic_block bb; 14785 FOR_EACH_BB (bb) 14786 { 14787 for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) 14788 update_stmt_if_modified (bsi_stmt (bsi)); 14789 } 14790 14791 14792 File: gccint.info, Node: SSA, Next: Alias analysis, Prev: SSA Operands, Up: Tree SSA 14793 14794 13.3 Static Single Assignment 14795 ============================= 14796 14797 Most of the tree optimizers rely on the data flow information provided 14798 by the Static Single Assignment (SSA) form. We implement the SSA form 14799 as described in `R. Cytron, J. Ferrante, B. Rosen, M. Wegman, and K. 14800 Zadeck. Efficiently Computing Static Single Assignment Form and the 14801 Control Dependence Graph. ACM Transactions on Programming Languages 14802 and Systems, 13(4):451-490, October 1991'. 14803 14804 The SSA form is based on the premise that program variables are 14805 assigned in exactly one location in the program. Multiple assignments 14806 to the same variable create new versions of that variable. Naturally, 14807 actual programs are seldom in SSA form initially because variables tend 14808 to be assigned multiple times. The compiler modifies the program 14809 representation so that every time a variable is assigned in the code, a 14810 new version of the variable is created. Different versions of the same 14811 variable are distinguished by subscripting the variable name with its 14812 version number. Variables used in the right-hand side of expressions 14813 are renamed so that their version number matches that of the most 14814 recent assignment. 14815 14816 We represent variable versions using `SSA_NAME' nodes. The renaming 14817 process in `tree-ssa.c' wraps every real and virtual operand with an 14818 `SSA_NAME' node which contains the version number and the statement 14819 that created the `SSA_NAME'. Only definitions and virtual definitions 14820 may create new `SSA_NAME' nodes. 14821 14822 Sometimes, flow of control makes it impossible to determine the most 14823 recent version of a variable. In these cases, the compiler inserts an 14824 artificial definition for that variable called "PHI function" or "PHI 14825 node". This new definition merges all the incoming versions of the 14826 variable to create a new name for it. For instance, 14827 14828 if (...) 14829 a_1 = 5; 14830 else if (...) 14831 a_2 = 2; 14832 else 14833 a_3 = 13; 14834 14835 # a_4 = PHI <a_1, a_2, a_3> 14836 return a_4; 14837 14838 Since it is not possible to determine which of the three branches will 14839 be taken at runtime, we don't know which of `a_1', `a_2' or `a_3' to 14840 use at the return statement. So, the SSA renamer creates a new version 14841 `a_4' which is assigned the result of "merging" `a_1', `a_2' and `a_3'. 14842 Hence, PHI nodes mean "one of these operands. I don't know which". 14843 14844 The following macros can be used to examine PHI nodes 14845 14846 -- Macro: PHI_RESULT (PHI) 14847 Returns the `SSA_NAME' created by PHI node PHI (i.e., PHI's LHS). 14848 14849 -- Macro: PHI_NUM_ARGS (PHI) 14850 Returns the number of arguments in PHI. This number is exactly 14851 the number of incoming edges to the basic block holding PHI. 14852 14853 -- Macro: PHI_ARG_ELT (PHI, I) 14854 Returns a tuple representing the Ith argument of PHI. Each 14855 element of this tuple contains an `SSA_NAME' VAR and the incoming 14856 edge through which VAR flows. 14857 14858 -- Macro: PHI_ARG_EDGE (PHI, I) 14859 Returns the incoming edge for the Ith argument of PHI. 14860 14861 -- Macro: PHI_ARG_DEF (PHI, I) 14862 Returns the `SSA_NAME' for the Ith argument of PHI. 14863 14864 13.3.1 Preserving the SSA form 14865 ------------------------------ 14866 14867 Some optimization passes make changes to the function that invalidate 14868 the SSA property. This can happen when a pass has added new symbols or 14869 changed the program so that variables that were previously aliased 14870 aren't anymore. Whenever something like this happens, the affected 14871 symbols must be renamed into SSA form again. Transformations that emit 14872 new code or replicate existing statements will also need to update the 14873 SSA form. 14874 14875 Since GCC implements two different SSA forms for register and virtual 14876 variables, keeping the SSA form up to date depends on whether you are 14877 updating register or virtual names. In both cases, the general idea 14878 behind incremental SSA updates is similar: when new SSA names are 14879 created, they typically are meant to replace other existing names in 14880 the program. 14881 14882 For instance, given the following code: 14883 14884 1 L0: 14885 2 x_1 = PHI (0, x_5) 14886 3 if (x_1 < 10) 14887 4 if (x_1 > 7) 14888 5 y_2 = 0 14889 6 else 14890 7 y_3 = x_1 + x_7 14891 8 endif 14892 9 x_5 = x_1 + 1 14893 10 goto L0; 14894 11 endif 14895 14896 Suppose that we insert new names `x_10' and `x_11' (lines `4' and `8'). 14897 14898 1 L0: 14899 2 x_1 = PHI (0, x_5) 14900 3 if (x_1 < 10) 14901 4 x_10 = ... 14902 5 if (x_1 > 7) 14903 6 y_2 = 0 14904 7 else 14905 8 x_11 = ... 14906 9 y_3 = x_1 + x_7 14907 10 endif 14908 11 x_5 = x_1 + 1 14909 12 goto L0; 14910 13 endif 14911 14912 We want to replace all the uses of `x_1' with the new definitions of 14913 `x_10' and `x_11'. Note that the only uses that should be replaced are 14914 those at lines `5', `9' and `11'. Also, the use of `x_7' at line `9' 14915 should _not_ be replaced (this is why we cannot just mark symbol `x' for 14916 renaming). 14917 14918 Additionally, we may need to insert a PHI node at line `11' because 14919 that is a merge point for `x_10' and `x_11'. So the use of `x_1' at 14920 line `11' will be replaced with the new PHI node. The insertion of PHI 14921 nodes is optional. They are not strictly necessary to preserve the SSA 14922 form, and depending on what the caller inserted, they may not even be 14923 useful for the optimizers. 14924 14925 Updating the SSA form is a two step process. First, the pass has to 14926 identify which names need to be updated and/or which symbols need to be 14927 renamed into SSA form for the first time. When new names are 14928 introduced to replace existing names in the program, the mapping 14929 between the old and the new names are registered by calling 14930 `register_new_name_mapping' (note that if your pass creates new code by 14931 duplicating basic blocks, the call to `tree_duplicate_bb' will set up 14932 the necessary mappings automatically). On the other hand, if your pass 14933 exposes a new symbol that should be put in SSA form for the first time, 14934 the new symbol should be registered with `mark_sym_for_renaming'. 14935 14936 After the replacement mappings have been registered and new symbols 14937 marked for renaming, a call to `update_ssa' makes the registered 14938 changes. This can be done with an explicit call or by creating `TODO' 14939 flags in the `tree_opt_pass' structure for your pass. There are 14940 several `TODO' flags that control the behavior of `update_ssa': 14941 14942 * `TODO_update_ssa'. Update the SSA form inserting PHI nodes for 14943 newly exposed symbols and virtual names marked for updating. When 14944 updating real names, only insert PHI nodes for a real name `O_j' 14945 in blocks reached by all the new and old definitions for `O_j'. 14946 If the iterated dominance frontier for `O_j' is not pruned, we may 14947 end up inserting PHI nodes in blocks that have one or more edges 14948 with no incoming definition for `O_j'. This would lead to 14949 uninitialized warnings for `O_j''s symbol. 14950 14951 * `TODO_update_ssa_no_phi'. Update the SSA form without inserting 14952 any new PHI nodes at all. This is used by passes that have either 14953 inserted all the PHI nodes themselves or passes that need only to 14954 patch use-def and def-def chains for virtuals (e.g., DCE). 14955 14956 * `TODO_update_ssa_full_phi'. Insert PHI nodes everywhere they are 14957 needed. No pruning of the IDF is done. This is used by passes 14958 that need the PHI nodes for `O_j' even if it means that some 14959 arguments will come from the default definition of `O_j''s symbol 14960 (e.g., `pass_linear_transform'). 14961 14962 WARNING: If you need to use this flag, chances are that your pass 14963 may be doing something wrong. Inserting PHI nodes for an old name 14964 where not all edges carry a new replacement may lead to silent 14965 codegen errors or spurious uninitialized warnings. 14966 14967 * `TODO_update_ssa_only_virtuals'. Passes that update the SSA form 14968 on their own may want to delegate the updating of virtual names to 14969 the generic updater. Since FUD chains are easier to maintain, 14970 this simplifies the work they need to do. NOTE: If this flag is 14971 used, any OLD->NEW mappings for real names are explicitly 14972 destroyed and only the symbols marked for renaming are processed. 14973 14974 13.3.2 Preserving the virtual SSA form 14975 -------------------------------------- 14976 14977 The virtual SSA form is harder to preserve than the non-virtual SSA form 14978 mainly because the set of virtual operands for a statement may change at 14979 what some would consider unexpected times. In general, statement 14980 modifications should be bracketed between calls to `push_stmt_changes' 14981 and `pop_stmt_changes'. For example, 14982 14983 munge_stmt (tree stmt) 14984 { 14985 push_stmt_changes (&stmt); 14986 ... rewrite STMT ... 14987 pop_stmt_changes (&stmt); 14988 } 14989 14990 The call to `push_stmt_changes' saves the current state of the 14991 statement operands and the call to `pop_stmt_changes' compares the 14992 saved state with the current one and does the appropriate symbol 14993 marking for the SSA renamer. 14994 14995 It is possible to modify several statements at a time, provided that 14996 `push_stmt_changes' and `pop_stmt_changes' are called in LIFO order, as 14997 when processing a stack of statements. 14998 14999 Additionally, if the pass discovers that it did not need to make 15000 changes to the statement after calling `push_stmt_changes', it can 15001 simply discard the topmost change buffer by calling 15002 `discard_stmt_changes'. This will avoid the expensive operand re-scan 15003 operation and the buffer comparison that determines if symbols need to 15004 be marked for renaming. 15005 15006 13.3.3 Examining `SSA_NAME' nodes 15007 --------------------------------- 15008 15009 The following macros can be used to examine `SSA_NAME' nodes 15010 15011 -- Macro: SSA_NAME_DEF_STMT (VAR) 15012 Returns the statement S that creates the `SSA_NAME' VAR. If S is 15013 an empty statement (i.e., `IS_EMPTY_STMT (S)' returns `true'), it 15014 means that the first reference to this variable is a USE or a VUSE. 15015 15016 -- Macro: SSA_NAME_VERSION (VAR) 15017 Returns the version number of the `SSA_NAME' object VAR. 15018 15019 13.3.4 Walking use-def chains 15020 ----------------------------- 15021 15022 -- Tree SSA function: void walk_use_def_chains (VAR, FN, DATA) 15023 Walks use-def chains starting at the `SSA_NAME' node VAR. Calls 15024 function FN at each reaching definition found. Function FN takes 15025 three arguments: VAR, its defining statement (DEF_STMT) and a 15026 generic pointer to whatever state information that FN may want to 15027 maintain (DATA). Function FN is able to stop the walk by 15028 returning `true', otherwise in order to continue the walk, FN 15029 should return `false'. 15030 15031 Note, that if DEF_STMT is a `PHI' node, the semantics are slightly 15032 different. For each argument ARG of the PHI node, this function 15033 will: 15034 15035 1. Walk the use-def chains for ARG. 15036 15037 2. Call `FN (ARG, PHI, DATA)'. 15038 15039 Note how the first argument to FN is no longer the original 15040 variable VAR, but the PHI argument currently being examined. If 15041 FN wants to get at VAR, it should call `PHI_RESULT' (PHI). 15042 15043 13.3.5 Walking the dominator tree 15044 --------------------------------- 15045 15046 -- Tree SSA function: void walk_dominator_tree (WALK_DATA, BB) 15047 This function walks the dominator tree for the current CFG calling 15048 a set of callback functions defined in STRUCT DOM_WALK_DATA in 15049 `domwalk.h'. The call back functions you need to define give you 15050 hooks to execute custom code at various points during traversal: 15051 15052 1. Once to initialize any local data needed while processing BB 15053 and its children. This local data is pushed into an internal 15054 stack which is automatically pushed and popped as the walker 15055 traverses the dominator tree. 15056 15057 2. Once before traversing all the statements in the BB. 15058 15059 3. Once for every statement inside BB. 15060 15061 4. Once after traversing all the statements and before recursing 15062 into BB's dominator children. 15063 15064 5. It then recurses into all the dominator children of BB. 15065 15066 6. After recursing into all the dominator children of BB it can, 15067 optionally, traverse every statement in BB again (i.e., 15068 repeating steps 2 and 3). 15069 15070 7. Once after walking the statements in BB and BB's dominator 15071 children. At this stage, the block local data stack is 15072 popped. 15073 15074 15075 File: gccint.info, Node: Alias analysis, Prev: SSA, Up: Tree SSA 15076 15077 13.4 Alias analysis 15078 =================== 15079 15080 Alias analysis proceeds in 4 main phases: 15081 15082 1. Structural alias analysis. 15083 15084 This phase walks the types for structure variables, and determines 15085 which of the fields can overlap using offset and size of each 15086 field. For each field, a "subvariable" called a "Structure field 15087 tag" (SFT) is created, which represents that field as a separate 15088 variable. All accesses that could possibly overlap with a given 15089 field will have virtual operands for the SFT of that field. 15090 15091 struct foo 15092 { 15093 int a; 15094 int b; 15095 } 15096 struct foo temp; 15097 int bar (void) 15098 { 15099 int tmp1, tmp2, tmp3; 15100 SFT.0_2 = VDEF <SFT.0_1> 15101 temp.a = 5; 15102 SFT.1_4 = VDEF <SFT.1_3> 15103 temp.b = 6; 15104 15105 VUSE <SFT.1_4> 15106 tmp1_5 = temp.b; 15107 VUSE <SFT.0_2> 15108 tmp2_6 = temp.a; 15109 15110 tmp3_7 = tmp1_5 + tmp2_6; 15111 return tmp3_7; 15112 } 15113 15114 If you copy the symbol tag for a variable for some reason, you 15115 probably also want to copy the subvariables for that variable. 15116 15117 2. Points-to and escape analysis. 15118 15119 This phase walks the use-def chains in the SSA web looking for 15120 three things: 15121 15122 * Assignments of the form `P_i = &VAR' 15123 15124 * Assignments of the form P_i = malloc() 15125 15126 * Pointers and ADDR_EXPR that escape the current function. 15127 15128 The concept of `escaping' is the same one used in the Java world. 15129 When a pointer or an ADDR_EXPR escapes, it means that it has been 15130 exposed outside of the current function. So, assignment to global 15131 variables, function arguments and returning a pointer are all 15132 escape sites. 15133 15134 This is where we are currently limited. Since not everything is 15135 renamed into SSA, we lose track of escape properties when a 15136 pointer is stashed inside a field in a structure, for instance. 15137 In those cases, we are assuming that the pointer does escape. 15138 15139 We use escape analysis to determine whether a variable is 15140 call-clobbered. Simply put, if an ADDR_EXPR escapes, then the 15141 variable is call-clobbered. If a pointer P_i escapes, then all 15142 the variables pointed-to by P_i (and its memory tag) also escape. 15143 15144 3. Compute flow-sensitive aliases 15145 15146 We have two classes of memory tags. Memory tags associated with 15147 the pointed-to data type of the pointers in the program. These 15148 tags are called "symbol memory tag" (SMT). The other class are 15149 those associated with SSA_NAMEs, called "name memory tag" (NMT). 15150 The basic idea is that when adding operands for an INDIRECT_REF 15151 *P_i, we will first check whether P_i has a name tag, if it does 15152 we use it, because that will have more precise aliasing 15153 information. Otherwise, we use the standard symbol tag. 15154 15155 In this phase, we go through all the pointers we found in 15156 points-to analysis and create alias sets for the name memory tags 15157 associated with each pointer P_i. If P_i escapes, we mark 15158 call-clobbered the variables it points to and its tag. 15159 15160 4. Compute flow-insensitive aliases 15161 15162 This pass will compare the alias set of every symbol memory tag and 15163 every addressable variable found in the program. Given a symbol 15164 memory tag SMT and an addressable variable V. If the alias sets 15165 of SMT and V conflict (as computed by may_alias_p), then V is 15166 marked as an alias tag and added to the alias set of SMT. 15167 15168 Every language that wishes to perform language-specific alias 15169 analysis should define a function that computes, given a `tree' 15170 node, an alias set for the node. Nodes in different alias sets 15171 are not allowed to alias. For an example, see the C front-end 15172 function `c_get_alias_set'. 15173 15174 For instance, consider the following function: 15175 15176 foo (int i) 15177 { 15178 int *p, *q, a, b; 15179 15180 if (i > 10) 15181 p = &a; 15182 else 15183 q = &b; 15184 15185 *p = 3; 15186 *q = 5; 15187 a = b + 2; 15188 return *p; 15189 } 15190 15191 After aliasing analysis has finished, the symbol memory tag for 15192 pointer `p' will have two aliases, namely variables `a' and `b'. Every 15193 time pointer `p' is dereferenced, we want to mark the operation as a 15194 potential reference to `a' and `b'. 15195 15196 foo (int i) 15197 { 15198 int *p, a, b; 15199 15200 if (i_2 > 10) 15201 p_4 = &a; 15202 else 15203 p_6 = &b; 15204 # p_1 = PHI <p_4(1), p_6(2)>; 15205 15206 # a_7 = VDEF <a_3>; 15207 # b_8 = VDEF <b_5>; 15208 *p_1 = 3; 15209 15210 # a_9 = VDEF <a_7> 15211 # VUSE <b_8> 15212 a_9 = b_8 + 2; 15213 15214 # VUSE <a_9>; 15215 # VUSE <b_8>; 15216 return *p_1; 15217 } 15218 15219 In certain cases, the list of may aliases for a pointer may grow too 15220 large. This may cause an explosion in the number of virtual operands 15221 inserted in the code. Resulting in increased memory consumption and 15222 compilation time. 15223 15224 When the number of virtual operands needed to represent aliased loads 15225 and stores grows too large (configurable with `--param 15226 max-aliased-vops'), alias sets are grouped to avoid severe compile-time 15227 slow downs and memory consumption. The alias grouping heuristic 15228 proceeds as follows: 15229 15230 1. Sort the list of pointers in decreasing number of contributed 15231 virtual operands. 15232 15233 2. Take the first pointer from the list and reverse the role of the 15234 memory tag and its aliases. Usually, whenever an aliased variable 15235 Vi is found to alias with a memory tag T, we add Vi to the 15236 may-aliases set for T. Meaning that after alias analysis, we will 15237 have: 15238 15239 may-aliases(T) = { V1, V2, V3, ..., Vn } 15240 15241 This means that every statement that references T, will get `n' 15242 virtual operands for each of the Vi tags. But, when alias 15243 grouping is enabled, we make T an alias tag and add it to the 15244 alias set of all the Vi variables: 15245 15246 may-aliases(V1) = { T } 15247 may-aliases(V2) = { T } 15248 ... 15249 may-aliases(Vn) = { T } 15250 15251 This has two effects: (a) statements referencing T will only get a 15252 single virtual operand, and, (b) all the variables Vi will now 15253 appear to alias each other. So, we lose alias precision to 15254 improve compile time. But, in theory, a program with such a high 15255 level of aliasing should not be very optimizable in the first 15256 place. 15257 15258 3. Since variables may be in the alias set of more than one memory 15259 tag, the grouping done in step (2) needs to be extended to all the 15260 memory tags that have a non-empty intersection with the 15261 may-aliases set of tag T. For instance, if we originally had 15262 these may-aliases sets: 15263 15264 may-aliases(T) = { V1, V2, V3 } 15265 may-aliases(R) = { V2, V4 } 15266 15267 In step (2) we would have reverted the aliases for T as: 15268 15269 may-aliases(V1) = { T } 15270 may-aliases(V2) = { T } 15271 may-aliases(V3) = { T } 15272 15273 But note that now V2 is no longer aliased with R. We could add R 15274 to may-aliases(V2), but we are in the process of grouping aliases 15275 to reduce virtual operands so what we do is add V4 to the grouping 15276 to obtain: 15277 15278 may-aliases(V1) = { T } 15279 may-aliases(V2) = { T } 15280 may-aliases(V3) = { T } 15281 may-aliases(V4) = { T } 15282 15283 4. If the total number of virtual operands due to aliasing is still 15284 above the threshold set by max-alias-vops, go back to (2). 15285 15286 15287 File: gccint.info, Node: Loop Analysis and Representation, Next: Machine Desc, Prev: Control Flow, Up: Top 15288 15289 14 Analysis and Representation of Loops 15290 *************************************** 15291 15292 GCC provides extensive infrastructure for work with natural loops, i.e., 15293 strongly connected components of CFG with only one entry block. This 15294 chapter describes representation of loops in GCC, both on GIMPLE and in 15295 RTL, as well as the interfaces to loop-related analyses (induction 15296 variable analysis and number of iterations analysis). 15297 15298 * Menu: 15299 15300 * Loop representation:: Representation and analysis of loops. 15301 * Loop querying:: Getting information about loops. 15302 * Loop manipulation:: Loop manipulation functions. 15303 * LCSSA:: Loop-closed SSA form. 15304 * Scalar evolutions:: Induction variables on GIMPLE. 15305 * loop-iv:: Induction variables on RTL. 15306 * Number of iterations:: Number of iterations analysis. 15307 * Dependency analysis:: Data dependency analysis. 15308 * Lambda:: Linear loop transformations framework. 15309 * Omega:: A solver for linear programming problems. 15310 15311 15312 File: gccint.info, Node: Loop representation, Next: Loop querying, Up: Loop Analysis and Representation 15313 15314 14.1 Loop representation 15315 ======================== 15316 15317 This chapter describes the representation of loops in GCC, and functions 15318 that can be used to build, modify and analyze this representation. Most 15319 of the interfaces and data structures are declared in `cfgloop.h'. At 15320 the moment, loop structures are analyzed and this information is 15321 updated only by the optimization passes that deal with loops, but some 15322 efforts are being made to make it available throughout most of the 15323 optimization passes. 15324 15325 In general, a natural loop has one entry block (header) and possibly 15326 several back edges (latches) leading to the header from the inside of 15327 the loop. Loops with several latches may appear if several loops share 15328 a single header, or if there is a branching in the middle of the loop. 15329 The representation of loops in GCC however allows only loops with a 15330 single latch. During loop analysis, headers of such loops are split and 15331 forwarder blocks are created in order to disambiguate their structures. 15332 Heuristic based on profile information and structure of the induction 15333 variables in the loops is used to determine whether the latches 15334 correspond to sub-loops or to control flow in a single loop. This means 15335 that the analysis sometimes changes the CFG, and if you run it in the 15336 middle of an optimization pass, you must be able to deal with the new 15337 blocks. You may avoid CFG changes by passing 15338 `LOOPS_MAY_HAVE_MULTIPLE_LATCHES' flag to the loop discovery, note 15339 however that most other loop manipulation functions will not work 15340 correctly for loops with multiple latch edges (the functions that only 15341 query membership of blocks to loops and subloop relationships, or 15342 enumerate and test loop exits, can be expected to work). 15343 15344 Body of the loop is the set of blocks that are dominated by its header, 15345 and reachable from its latch against the direction of edges in CFG. The 15346 loops are organized in a containment hierarchy (tree) such that all the 15347 loops immediately contained inside loop L are the children of L in the 15348 tree. This tree is represented by the `struct loops' structure. The 15349 root of this tree is a fake loop that contains all blocks in the 15350 function. Each of the loops is represented in a `struct loop' 15351 structure. Each loop is assigned an index (`num' field of the `struct 15352 loop' structure), and the pointer to the loop is stored in the 15353 corresponding field of the `larray' vector in the loops structure. The 15354 indices do not have to be continuous, there may be empty (`NULL') 15355 entries in the `larray' created by deleting loops. Also, there is no 15356 guarantee on the relative order of a loop and its subloops in the 15357 numbering. The index of a loop never changes. 15358 15359 The entries of the `larray' field should not be accessed directly. 15360 The function `get_loop' returns the loop description for a loop with 15361 the given index. `number_of_loops' function returns number of loops in 15362 the function. To traverse all loops, use `FOR_EACH_LOOP' macro. The 15363 `flags' argument of the macro is used to determine the direction of 15364 traversal and the set of loops visited. Each loop is guaranteed to be 15365 visited exactly once, regardless of the changes to the loop tree, and 15366 the loops may be removed during the traversal. The newly created loops 15367 are never traversed, if they need to be visited, this must be done 15368 separately after their creation. The `FOR_EACH_LOOP' macro allocates 15369 temporary variables. If the `FOR_EACH_LOOP' loop were ended using 15370 break or goto, they would not be released; `FOR_EACH_LOOP_BREAK' macro 15371 must be used instead. 15372 15373 Each basic block contains the reference to the innermost loop it 15374 belongs to (`loop_father'). For this reason, it is only possible to 15375 have one `struct loops' structure initialized at the same time for each 15376 CFG. The global variable `current_loops' contains the `struct loops' 15377 structure. Many of the loop manipulation functions assume that 15378 dominance information is up-to-date. 15379 15380 The loops are analyzed through `loop_optimizer_init' function. The 15381 argument of this function is a set of flags represented in an integer 15382 bitmask. These flags specify what other properties of the loop 15383 structures should be calculated/enforced and preserved later: 15384 15385 * `LOOPS_MAY_HAVE_MULTIPLE_LATCHES': If this flag is set, no changes 15386 to CFG will be performed in the loop analysis, in particular, 15387 loops with multiple latch edges will not be disambiguated. If a 15388 loop has multiple latches, its latch block is set to NULL. Most of 15389 the loop manipulation functions will not work for loops in this 15390 shape. No other flags that require CFG changes can be passed to 15391 loop_optimizer_init. 15392 15393 * `LOOPS_HAVE_PREHEADERS': Forwarder blocks are created in such a 15394 way that each loop has only one entry edge, and additionally, the 15395 source block of this entry edge has only one successor. This 15396 creates a natural place where the code can be moved out of the 15397 loop, and ensures that the entry edge of the loop leads from its 15398 immediate super-loop. 15399 15400 * `LOOPS_HAVE_SIMPLE_LATCHES': Forwarder blocks are created to force 15401 the latch block of each loop to have only one successor. This 15402 ensures that the latch of the loop does not belong to any of its 15403 sub-loops, and makes manipulation with the loops significantly 15404 easier. Most of the loop manipulation functions assume that the 15405 loops are in this shape. Note that with this flag, the "normal" 15406 loop without any control flow inside and with one exit consists of 15407 two basic blocks. 15408 15409 * `LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS': Basic blocks and edges in 15410 the strongly connected components that are not natural loops (have 15411 more than one entry block) are marked with `BB_IRREDUCIBLE_LOOP' 15412 and `EDGE_IRREDUCIBLE_LOOP' flags. The flag is not set for blocks 15413 and edges that belong to natural loops that are in such an 15414 irreducible region (but it is set for the entry and exit edges of 15415 such a loop, if they lead to/from this region). 15416 15417 * `LOOPS_HAVE_RECORDED_EXITS': The lists of exits are recorded and 15418 updated for each loop. This makes some functions (e.g., 15419 `get_loop_exit_edges') more efficient. Some functions (e.g., 15420 `single_exit') can be used only if the lists of exits are recorded. 15421 15422 These properties may also be computed/enforced later, using functions 15423 `create_preheaders', `force_single_succ_latches', 15424 `mark_irreducible_loops' and `record_loop_exits'. 15425 15426 The memory occupied by the loops structures should be freed with 15427 `loop_optimizer_finalize' function. 15428 15429 The CFG manipulation functions in general do not update loop 15430 structures. Specialized versions that additionally do so are provided 15431 for the most common tasks. On GIMPLE, `cleanup_tree_cfg_loop' function 15432 can be used to cleanup CFG while updating the loops structures if 15433 `current_loops' is set. 15434 15435 15436 File: gccint.info, Node: Loop querying, Next: Loop manipulation, Prev: Loop representation, Up: Loop Analysis and Representation 15437 15438 14.2 Loop querying 15439 ================== 15440 15441 The functions to query the information about loops are declared in 15442 `cfgloop.h'. Some of the information can be taken directly from the 15443 structures. `loop_father' field of each basic block contains the 15444 innermost loop to that the block belongs. The most useful fields of 15445 loop structure (that are kept up-to-date at all times) are: 15446 15447 * `header', `latch': Header and latch basic blocks of the loop. 15448 15449 * `num_nodes': Number of basic blocks in the loop (including the 15450 basic blocks of the sub-loops). 15451 15452 * `depth': The depth of the loop in the loops tree, i.e., the number 15453 of super-loops of the loop. 15454 15455 * `outer', `inner', `next': The super-loop, the first sub-loop, and 15456 the sibling of the loop in the loops tree. 15457 15458 There are other fields in the loop structures, many of them used only 15459 by some of the passes, or not updated during CFG changes; in general, 15460 they should not be accessed directly. 15461 15462 The most important functions to query loop structures are: 15463 15464 * `flow_loops_dump': Dumps the information about loops to a file. 15465 15466 * `verify_loop_structure': Checks consistency of the loop structures. 15467 15468 * `loop_latch_edge': Returns the latch edge of a loop. 15469 15470 * `loop_preheader_edge': If loops have preheaders, returns the 15471 preheader edge of a loop. 15472 15473 * `flow_loop_nested_p': Tests whether loop is a sub-loop of another 15474 loop. 15475 15476 * `flow_bb_inside_loop_p': Tests whether a basic block belongs to a 15477 loop (including its sub-loops). 15478 15479 * `find_common_loop': Finds the common super-loop of two loops. 15480 15481 * `superloop_at_depth': Returns the super-loop of a loop with the 15482 given depth. 15483 15484 * `tree_num_loop_insns', `num_loop_insns': Estimates the number of 15485 insns in the loop, on GIMPLE and on RTL. 15486 15487 * `loop_exit_edge_p': Tests whether edge is an exit from a loop. 15488 15489 * `mark_loop_exit_edges': Marks all exit edges of all loops with 15490 `EDGE_LOOP_EXIT' flag. 15491 15492 * `get_loop_body', `get_loop_body_in_dom_order', 15493 `get_loop_body_in_bfs_order': Enumerates the basic blocks in the 15494 loop in depth-first search order in reversed CFG, ordered by 15495 dominance relation, and breath-first search order, respectively. 15496 15497 * `single_exit': Returns the single exit edge of the loop, or `NULL' 15498 if the loop has more than one exit. You can only use this 15499 function if LOOPS_HAVE_MARKED_SINGLE_EXITS property is used. 15500 15501 * `get_loop_exit_edges': Enumerates the exit edges of a loop. 15502 15503 * `just_once_each_iteration_p': Returns true if the basic block is 15504 executed exactly once during each iteration of a loop (that is, it 15505 does not belong to a sub-loop, and it dominates the latch of the 15506 loop). 15507 15508 15509 File: gccint.info, Node: Loop manipulation, Next: LCSSA, Prev: Loop querying, Up: Loop Analysis and Representation 15510 15511 14.3 Loop manipulation 15512 ====================== 15513 15514 The loops tree can be manipulated using the following functions: 15515 15516 * `flow_loop_tree_node_add': Adds a node to the tree. 15517 15518 * `flow_loop_tree_node_remove': Removes a node from the tree. 15519 15520 * `add_bb_to_loop': Adds a basic block to a loop. 15521 15522 * `remove_bb_from_loops': Removes a basic block from loops. 15523 15524 Most low-level CFG functions update loops automatically. The following 15525 functions handle some more complicated cases of CFG manipulations: 15526 15527 * `remove_path': Removes an edge and all blocks it dominates. 15528 15529 * `split_loop_exit_edge': Splits exit edge of the loop, ensuring 15530 that PHI node arguments remain in the loop (this ensures that 15531 loop-closed SSA form is preserved). Only useful on GIMPLE. 15532 15533 Finally, there are some higher-level loop transformations implemented. 15534 While some of them are written so that they should work on non-innermost 15535 loops, they are mostly untested in that case, and at the moment, they 15536 are only reliable for the innermost loops: 15537 15538 * `create_iv': Creates a new induction variable. Only works on 15539 GIMPLE. `standard_iv_increment_position' can be used to find a 15540 suitable place for the iv increment. 15541 15542 * `duplicate_loop_to_header_edge', 15543 `tree_duplicate_loop_to_header_edge': These functions (on RTL and 15544 on GIMPLE) duplicate the body of the loop prescribed number of 15545 times on one of the edges entering loop header, thus performing 15546 either loop unrolling or loop peeling. `can_duplicate_loop_p' 15547 (`can_unroll_loop_p' on GIMPLE) must be true for the duplicated 15548 loop. 15549 15550 * `loop_version', `tree_ssa_loop_version': These function create a 15551 copy of a loop, and a branch before them that selects one of them 15552 depending on the prescribed condition. This is useful for 15553 optimizations that need to verify some assumptions in runtime (one 15554 of the copies of the loop is usually left unchanged, while the 15555 other one is transformed in some way). 15556 15557 * `tree_unroll_loop': Unrolls the loop, including peeling the extra 15558 iterations to make the number of iterations divisible by unroll 15559 factor, updating the exit condition, and removing the exits that 15560 now cannot be taken. Works only on GIMPLE. 15561 15562 15563 File: gccint.info, Node: LCSSA, Next: Scalar evolutions, Prev: Loop manipulation, Up: Loop Analysis and Representation 15564 15565 14.4 Loop-closed SSA form 15566 ========================= 15567 15568 Throughout the loop optimizations on tree level, one extra condition is 15569 enforced on the SSA form: No SSA name is used outside of the loop in 15570 that it is defined. The SSA form satisfying this condition is called 15571 "loop-closed SSA form" - LCSSA. To enforce LCSSA, PHI nodes must be 15572 created at the exits of the loops for the SSA names that are used 15573 outside of them. Only the real operands (not virtual SSA names) are 15574 held in LCSSA, in order to save memory. 15575 15576 There are various benefits of LCSSA: 15577 15578 * Many optimizations (value range analysis, final value replacement) 15579 are interested in the values that are defined in the loop and used 15580 outside of it, i.e., exactly those for that we create new PHI 15581 nodes. 15582 15583 * In induction variable analysis, it is not necessary to specify the 15584 loop in that the analysis should be performed - the scalar 15585 evolution analysis always returns the results with respect to the 15586 loop in that the SSA name is defined. 15587 15588 * It makes updating of SSA form during loop transformations simpler. 15589 Without LCSSA, operations like loop unrolling may force creation 15590 of PHI nodes arbitrarily far from the loop, while in LCSSA, the 15591 SSA form can be updated locally. However, since we only keep real 15592 operands in LCSSA, we cannot use this advantage (we could have 15593 local updating of real operands, but it is not much more efficient 15594 than to use generic SSA form updating for it as well; the amount 15595 of changes to SSA is the same). 15596 15597 However, it also means LCSSA must be updated. This is usually 15598 straightforward, unless you create a new value in loop and use it 15599 outside, or unless you manipulate loop exit edges (functions are 15600 provided to make these manipulations simple). 15601 `rewrite_into_loop_closed_ssa' is used to rewrite SSA form to LCSSA, 15602 and `verify_loop_closed_ssa' to check that the invariant of LCSSA is 15603 preserved. 15604 15605 15606 File: gccint.info, Node: Scalar evolutions, Next: loop-iv, Prev: LCSSA, Up: Loop Analysis and Representation 15607 15608 14.5 Scalar evolutions 15609 ====================== 15610 15611 Scalar evolutions (SCEV) are used to represent results of induction 15612 variable analysis on GIMPLE. They enable us to represent variables with 15613 complicated behavior in a simple and consistent way (we only use it to 15614 express values of polynomial induction variables, but it is possible to 15615 extend it). The interfaces to SCEV analysis are declared in 15616 `tree-scalar-evolution.h'. To use scalar evolutions analysis, 15617 `scev_initialize' must be used. To stop using SCEV, `scev_finalize' 15618 should be used. SCEV analysis caches results in order to save time and 15619 memory. This cache however is made invalid by most of the loop 15620 transformations, including removal of code. If such a transformation 15621 is performed, `scev_reset' must be called to clean the caches. 15622 15623 Given an SSA name, its behavior in loops can be analyzed using the 15624 `analyze_scalar_evolution' function. The returned SCEV however does 15625 not have to be fully analyzed and it may contain references to other 15626 SSA names defined in the loop. To resolve these (potentially 15627 recursive) references, `instantiate_parameters' or `resolve_mixers' 15628 functions must be used. `instantiate_parameters' is useful when you 15629 use the results of SCEV only for some analysis, and when you work with 15630 whole nest of loops at once. It will try replacing all SSA names by 15631 their SCEV in all loops, including the super-loops of the current loop, 15632 thus providing a complete information about the behavior of the 15633 variable in the loop nest. `resolve_mixers' is useful if you work with 15634 only one loop at a time, and if you possibly need to create code based 15635 on the value of the induction variable. It will only resolve the SSA 15636 names defined in the current loop, leaving the SSA names defined 15637 outside unchanged, even if their evolution in the outer loops is known. 15638 15639 The SCEV is a normal tree expression, except for the fact that it may 15640 contain several special tree nodes. One of them is `SCEV_NOT_KNOWN', 15641 used for SSA names whose value cannot be expressed. The other one is 15642 `POLYNOMIAL_CHREC'. Polynomial chrec has three arguments - base, step 15643 and loop (both base and step may contain further polynomial chrecs). 15644 Type of the expression and of base and step must be the same. A 15645 variable has evolution `POLYNOMIAL_CHREC(base, step, loop)' if it is 15646 (in the specified loop) equivalent to `x_1' in the following example 15647 15648 while (...) 15649 { 15650 x_1 = phi (base, x_2); 15651 x_2 = x_1 + step; 15652 } 15653 15654 Note that this includes the language restrictions on the operations. 15655 For example, if we compile C code and `x' has signed type, then the 15656 overflow in addition would cause undefined behavior, and we may assume 15657 that this does not happen. Hence, the value with this SCEV cannot 15658 overflow (which restricts the number of iterations of such a loop). 15659 15660 In many cases, one wants to restrict the attention just to affine 15661 induction variables. In this case, the extra expressive power of SCEV 15662 is not useful, and may complicate the optimizations. In this case, 15663 `simple_iv' function may be used to analyze a value - the result is a 15664 loop-invariant base and step. 15665 15666 15667 File: gccint.info, Node: loop-iv, Next: Number of iterations, Prev: Scalar evolutions, Up: Loop Analysis and Representation 15668 15669 14.6 IV analysis on RTL 15670 ======================= 15671 15672 The induction variable on RTL is simple and only allows analysis of 15673 affine induction variables, and only in one loop at once. The interface 15674 is declared in `cfgloop.h'. Before analyzing induction variables in a 15675 loop L, `iv_analysis_loop_init' function must be called on L. After 15676 the analysis (possibly calling `iv_analysis_loop_init' for several 15677 loops) is finished, `iv_analysis_done' should be called. The following 15678 functions can be used to access the results of the analysis: 15679 15680 * `iv_analyze': Analyzes a single register used in the given insn. 15681 If no use of the register in this insn is found, the following 15682 insns are scanned, so that this function can be called on the insn 15683 returned by get_condition. 15684 15685 * `iv_analyze_result': Analyzes result of the assignment in the 15686 given insn. 15687 15688 * `iv_analyze_expr': Analyzes a more complicated expression. All 15689 its operands are analyzed by `iv_analyze', and hence they must be 15690 used in the specified insn or one of the following insns. 15691 15692 The description of the induction variable is provided in `struct 15693 rtx_iv'. In order to handle subregs, the representation is a bit 15694 complicated; if the value of the `extend' field is not `UNKNOWN', the 15695 value of the induction variable in the i-th iteration is 15696 15697 delta + mult * extend_{extend_mode} (subreg_{mode} (base + i * step)), 15698 15699 with the following exception: if `first_special' is true, then the 15700 value in the first iteration (when `i' is zero) is `delta + mult * 15701 base'. However, if `extend' is equal to `UNKNOWN', then 15702 `first_special' must be false, `delta' 0, `mult' 1 and the value in the 15703 i-th iteration is 15704 15705 subreg_{mode} (base + i * step) 15706 15707 The function `get_iv_value' can be used to perform these calculations. 15708 15709 15710 File: gccint.info, Node: Number of iterations, Next: Dependency analysis, Prev: loop-iv, Up: Loop Analysis and Representation 15711 15712 14.7 Number of iterations analysis 15713 ================================== 15714 15715 Both on GIMPLE and on RTL, there are functions available to determine 15716 the number of iterations of a loop, with a similar interface. The 15717 number of iterations of a loop in GCC is defined as the number of 15718 executions of the loop latch. In many cases, it is not possible to 15719 determine the number of iterations unconditionally - the determined 15720 number is correct only if some assumptions are satisfied. The analysis 15721 tries to verify these conditions using the information contained in the 15722 program; if it fails, the conditions are returned together with the 15723 result. The following information and conditions are provided by the 15724 analysis: 15725 15726 * `assumptions': If this condition is false, the rest of the 15727 information is invalid. 15728 15729 * `noloop_assumptions' on RTL, `may_be_zero' on GIMPLE: If this 15730 condition is true, the loop exits in the first iteration. 15731 15732 * `infinite': If this condition is true, the loop is infinite. This 15733 condition is only available on RTL. On GIMPLE, conditions for 15734 finiteness of the loop are included in `assumptions'. 15735 15736 * `niter_expr' on RTL, `niter' on GIMPLE: The expression that gives 15737 number of iterations. The number of iterations is defined as the 15738 number of executions of the loop latch. 15739 15740 Both on GIMPLE and on RTL, it necessary for the induction variable 15741 analysis framework to be initialized (SCEV on GIMPLE, loop-iv on RTL). 15742 On GIMPLE, the results are stored to `struct tree_niter_desc' 15743 structure. Number of iterations before the loop is exited through a 15744 given exit can be determined using `number_of_iterations_exit' 15745 function. On RTL, the results are returned in `struct niter_desc' 15746 structure. The corresponding function is named `check_simple_exit'. 15747 There are also functions that pass through all the exits of a loop and 15748 try to find one with easy to determine number of iterations - 15749 `find_loop_niter' on GIMPLE and `find_simple_exit' on RTL. Finally, 15750 there are functions that provide the same information, but additionally 15751 cache it, so that repeated calls to number of iterations are not so 15752 costly - `number_of_latch_executions' on GIMPLE and 15753 `get_simple_loop_desc' on RTL. 15754 15755 Note that some of these functions may behave slightly differently than 15756 others - some of them return only the expression for the number of 15757 iterations, and fail if there are some assumptions. The function 15758 `number_of_latch_executions' works only for single-exit loops. The 15759 function `number_of_cond_exit_executions' can be used to determine 15760 number of executions of the exit condition of a single-exit loop (i.e., 15761 the `number_of_latch_executions' increased by one). 15762 15763 15764 File: gccint.info, Node: Dependency analysis, Next: Lambda, Prev: Number of iterations, Up: Loop Analysis and Representation 15765 15766 14.8 Data Dependency Analysis 15767 ============================= 15768 15769 The code for the data dependence analysis can be found in 15770 `tree-data-ref.c' and its interface and data structures are described 15771 in `tree-data-ref.h'. The function that computes the data dependences 15772 for all the array and pointer references for a given loop is 15773 `compute_data_dependences_for_loop'. This function is currently used 15774 by the linear loop transform and the vectorization passes. Before 15775 calling this function, one has to allocate two vectors: a first vector 15776 will contain the set of data references that are contained in the 15777 analyzed loop body, and the second vector will contain the dependence 15778 relations between the data references. Thus if the vector of data 15779 references is of size `n', the vector containing the dependence 15780 relations will contain `n*n' elements. However if the analyzed loop 15781 contains side effects, such as calls that potentially can interfere 15782 with the data references in the current analyzed loop, the analysis 15783 stops while scanning the loop body for data references, and inserts a 15784 single `chrec_dont_know' in the dependence relation array. 15785 15786 The data references are discovered in a particular order during the 15787 scanning of the loop body: the loop body is analyzed in execution order, 15788 and the data references of each statement are pushed at the end of the 15789 data reference array. Two data references syntactically occur in the 15790 program in the same order as in the array of data references. This 15791 syntactic order is important in some classical data dependence tests, 15792 and mapping this order to the elements of this array avoids costly 15793 queries to the loop body representation. 15794 15795 Three types of data references are currently handled: ARRAY_REF, 15796 INDIRECT_REF and COMPONENT_REF. The data structure for the data 15797 reference is `data_reference', where `data_reference_p' is a name of a 15798 pointer to the data reference structure. The structure contains the 15799 following elements: 15800 15801 * `base_object_info': Provides information about the base object of 15802 the data reference and its access functions. These access functions 15803 represent the evolution of the data reference in the loop relative 15804 to its base, in keeping with the classical meaning of the data 15805 reference access function for the support of arrays. For example, 15806 for a reference `a.b[i][j]', the base object is `a.b' and the 15807 access functions, one for each array subscript, are: `{i_init, + 15808 i_step}_1, {j_init, +, j_step}_2'. 15809 15810 * `first_location_in_loop': Provides information about the first 15811 location accessed by the data reference in the loop and about the 15812 access function used to represent evolution relative to this 15813 location. This data is used to support pointers, and is not used 15814 for arrays (for which we have base objects). Pointer accesses are 15815 represented as a one-dimensional access that starts from the first 15816 location accessed in the loop. For example: 15817 15818 for1 i 15819 for2 j 15820 *((int *)p + i + j) = a[i][j]; 15821 15822 The access function of the pointer access is `{0, + 4B}_for2' 15823 relative to `p + i'. The access functions of the array are 15824 `{i_init, + i_step}_for1' and `{j_init, +, j_step}_for2' relative 15825 to `a'. 15826 15827 Usually, the object the pointer refers to is either unknown, or we 15828 can't prove that the access is confined to the boundaries of a 15829 certain object. 15830 15831 Two data references can be compared only if at least one of these 15832 two representations has all its fields filled for both data 15833 references. 15834 15835 The current strategy for data dependence tests is as follows: If 15836 both `a' and `b' are represented as arrays, compare 15837 `a.base_object' and `b.base_object'; if they are equal, apply 15838 dependence tests (use access functions based on base_objects). 15839 Else if both `a' and `b' are represented as pointers, compare 15840 `a.first_location' and `b.first_location'; if they are equal, 15841 apply dependence tests (use access functions based on first 15842 location). However, if `a' and `b' are represented differently, 15843 only try to prove that the bases are definitely different. 15844 15845 * Aliasing information. 15846 15847 * Alignment information. 15848 15849 The structure describing the relation between two data references is 15850 `data_dependence_relation' and the shorter name for a pointer to such a 15851 structure is `ddr_p'. This structure contains: 15852 15853 * a pointer to each data reference, 15854 15855 * a tree node `are_dependent' that is set to `chrec_known' if the 15856 analysis has proved that there is no dependence between these two 15857 data references, `chrec_dont_know' if the analysis was not able to 15858 determine any useful result and potentially there could exist a 15859 dependence between these data references, and `are_dependent' is 15860 set to `NULL_TREE' if there exist a dependence relation between the 15861 data references, and the description of this dependence relation is 15862 given in the `subscripts', `dir_vects', and `dist_vects' arrays, 15863 15864 * a boolean that determines whether the dependence relation can be 15865 represented by a classical distance vector, 15866 15867 * an array `subscripts' that contains a description of each 15868 subscript of the data references. Given two array accesses a 15869 subscript is the tuple composed of the access functions for a given 15870 dimension. For example, given `A[f1][f2][f3]' and 15871 `B[g1][g2][g3]', there are three subscripts: `(f1, g1), (f2, g2), 15872 (f3, g3)'. 15873 15874 * two arrays `dir_vects' and `dist_vects' that contain classical 15875 representations of the data dependences under the form of 15876 direction and distance dependence vectors, 15877 15878 * an array of loops `loop_nest' that contains the loops to which the 15879 distance and direction vectors refer to. 15880 15881 Several functions for pretty printing the information extracted by the 15882 data dependence analysis are available: `dump_ddrs' prints with a 15883 maximum verbosity the details of a data dependence relations array, 15884 `dump_dist_dir_vectors' prints only the classical distance and 15885 direction vectors for a data dependence relations array, and 15886 `dump_data_references' prints the details of the data references 15887 contained in a data reference array. 15888 15889 15890 File: gccint.info, Node: Lambda, Next: Omega, Prev: Dependency analysis, Up: Loop Analysis and Representation 15891 15892 14.9 Linear loop transformations framework 15893 ========================================== 15894 15895 Lambda is a framework that allows transformations of loops using 15896 non-singular matrix based transformations of the iteration space and 15897 loop bounds. This allows compositions of skewing, scaling, interchange, 15898 and reversal transformations. These transformations are often used to 15899 improve cache behavior or remove inner loop dependencies to allow 15900 parallelization and vectorization to take place. 15901 15902 To perform these transformations, Lambda requires that the loopnest be 15903 converted into a internal form that can be matrix transformed easily. 15904 To do this conversion, the function `gcc_loopnest_to_lambda_loopnest' 15905 is provided. If the loop cannot be transformed using lambda, this 15906 function will return NULL. 15907 15908 Once a `lambda_loopnest' is obtained from the conversion function, it 15909 can be transformed by using `lambda_loopnest_transform', which takes a 15910 transformation matrix to apply. Note that it is up to the caller to 15911 verify that the transformation matrix is legal to apply to the loop 15912 (dependence respecting, etc). Lambda simply applies whatever matrix it 15913 is told to provide. It can be extended to make legal matrices out of 15914 any non-singular matrix, but this is not currently implemented. 15915 Legality of a matrix for a given loopnest can be verified using 15916 `lambda_transform_legal_p'. 15917 15918 Given a transformed loopnest, conversion back into gcc IR is done by 15919 `lambda_loopnest_to_gcc_loopnest'. This function will modify the loops 15920 so that they match the transformed loopnest. 15921 15922 15923 File: gccint.info, Node: Omega, Prev: Lambda, Up: Loop Analysis and Representation 15924 15925 14.10 Omega a solver for linear programming problems 15926 ==================================================== 15927 15928 The data dependence analysis contains several solvers triggered 15929 sequentially from the less complex ones to the more sophisticated. For 15930 ensuring the consistency of the results of these solvers, a data 15931 dependence check pass has been implemented based on two different 15932 solvers. The second method that has been integrated to GCC is based on 15933 the Omega dependence solver, written in the 1990's by William Pugh and 15934 David Wonnacott. Data dependence tests can be formulated using a 15935 subset of the Presburger arithmetics that can be translated to linear 15936 constraint systems. These linear constraint systems can then be solved 15937 using the Omega solver. 15938 15939 The Omega solver is using Fourier-Motzkin's algorithm for variable 15940 elimination: a linear constraint system containing `n' variables is 15941 reduced to a linear constraint system with `n-1' variables. The Omega 15942 solver can also be used for solving other problems that can be 15943 expressed under the form of a system of linear equalities and 15944 inequalities. The Omega solver is known to have an exponential worst 15945 case, also known under the name of "omega nightmare" in the literature, 15946 but in practice, the omega test is known to be efficient for the common 15947 data dependence tests. 15948 15949 The interface used by the Omega solver for describing the linear 15950 programming problems is described in `omega.h', and the solver is 15951 `omega_solve_problem'. 15952 15953 15954 File: gccint.info, Node: Control Flow, Next: Loop Analysis and Representation, Prev: Tree SSA, Up: Top 15955 15956 15 Control Flow Graph 15957 ********************* 15958 15959 A control flow graph (CFG) is a data structure built on top of the 15960 intermediate code representation (the RTL or `tree' instruction stream) 15961 abstracting the control flow behavior of a function that is being 15962 compiled. The CFG is a directed graph where the vertices represent 15963 basic blocks and edges represent possible transfer of control flow from 15964 one basic block to another. The data structures used to represent the 15965 control flow graph are defined in `basic-block.h'. 15966 15967 * Menu: 15968 15969 * Basic Blocks:: The definition and representation of basic blocks. 15970 * Edges:: Types of edges and their representation. 15971 * Profile information:: Representation of frequencies and probabilities. 15972 * Maintaining the CFG:: Keeping the control flow graph and up to date. 15973 * Liveness information:: Using and maintaining liveness information. 15974 15975 15976 File: gccint.info, Node: Basic Blocks, Next: Edges, Up: Control Flow 15977 15978 15.1 Basic Blocks 15979 ================= 15980 15981 A basic block is a straight-line sequence of code with only one entry 15982 point and only one exit. In GCC, basic blocks are represented using 15983 the `basic_block' data type. 15984 15985 Two pointer members of the `basic_block' structure are the pointers 15986 `next_bb' and `prev_bb'. These are used to keep doubly linked chain of 15987 basic blocks in the same order as the underlying instruction stream. 15988 The chain of basic blocks is updated transparently by the provided API 15989 for manipulating the CFG. The macro `FOR_EACH_BB' can be used to visit 15990 all the basic blocks in lexicographical order. Dominator traversals 15991 are also possible using `walk_dominator_tree'. Given two basic blocks 15992 A and B, block A dominates block B if A is _always_ executed before B. 15993 15994 The `BASIC_BLOCK' array contains all basic blocks in an unspecified 15995 order. Each `basic_block' structure has a field that holds a unique 15996 integer identifier `index' that is the index of the block in the 15997 `BASIC_BLOCK' array. The total number of basic blocks in the function 15998 is `n_basic_blocks'. Both the basic block indices and the total number 15999 of basic blocks may vary during the compilation process, as passes 16000 reorder, create, duplicate, and destroy basic blocks. The index for 16001 any block should never be greater than `last_basic_block'. 16002 16003 Special basic blocks represent possible entry and exit points of a 16004 function. These blocks are called `ENTRY_BLOCK_PTR' and 16005 `EXIT_BLOCK_PTR'. These blocks do not contain any code, and are not 16006 elements of the `BASIC_BLOCK' array. Therefore they have been assigned 16007 unique, negative index numbers. 16008 16009 Each `basic_block' also contains pointers to the first instruction 16010 (the "head") and the last instruction (the "tail") or "end" of the 16011 instruction stream contained in a basic block. In fact, since the 16012 `basic_block' data type is used to represent blocks in both major 16013 intermediate representations of GCC (`tree' and RTL), there are 16014 pointers to the head and end of a basic block for both representations. 16015 16016 For RTL, these pointers are `rtx head, end'. In the RTL function 16017 representation, the head pointer always points either to a 16018 `NOTE_INSN_BASIC_BLOCK' or to a `CODE_LABEL', if present. In the RTL 16019 representation of a function, the instruction stream contains not only 16020 the "real" instructions, but also "notes". Any function that moves or 16021 duplicates the basic blocks needs to take care of updating of these 16022 notes. Many of these notes expect that the instruction stream consists 16023 of linear regions, making such updates difficult. The 16024 `NOTE_INSN_BASIC_BLOCK' note is the only kind of note that may appear 16025 in the instruction stream contained in a basic block. The instruction 16026 stream of a basic block always follows a `NOTE_INSN_BASIC_BLOCK', but 16027 zero or more `CODE_LABEL' nodes can precede the block note. A basic 16028 block ends by control flow instruction or last instruction before 16029 following `CODE_LABEL' or `NOTE_INSN_BASIC_BLOCK'. A `CODE_LABEL' 16030 cannot appear in the instruction stream of a basic block. 16031 16032 In addition to notes, the jump table vectors are also represented as 16033 "pseudo-instructions" inside the insn stream. These vectors never 16034 appear in the basic block and should always be placed just after the 16035 table jump instructions referencing them. After removing the 16036 table-jump it is often difficult to eliminate the code computing the 16037 address and referencing the vector, so cleaning up these vectors is 16038 postponed until after liveness analysis. Thus the jump table vectors 16039 may appear in the insn stream unreferenced and without any purpose. 16040 Before any edge is made "fall-thru", the existence of such construct in 16041 the way needs to be checked by calling `can_fallthru' function. 16042 16043 For the `tree' representation, the head and end of the basic block are 16044 being pointed to by the `stmt_list' field, but this special `tree' 16045 should never be referenced directly. Instead, at the tree level 16046 abstract containers and iterators are used to access statements and 16047 expressions in basic blocks. These iterators are called "block 16048 statement iterators" (BSIs). Grep for `^bsi' in the various `tree-*' 16049 files. The following snippet will pretty-print all the statements of 16050 the program in the GIMPLE representation. 16051 16052 FOR_EACH_BB (bb) 16053 { 16054 block_stmt_iterator si; 16055 16056 for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si)) 16057 { 16058 tree stmt = bsi_stmt (si); 16059 print_generic_stmt (stderr, stmt, 0); 16060 } 16061 } 16062 16063 16064 File: gccint.info, Node: Edges, Next: Profile information, Prev: Basic Blocks, Up: Control Flow 16065 16066 15.2 Edges 16067 ========== 16068 16069 Edges represent possible control flow transfers from the end of some 16070 basic block A to the head of another basic block B. We say that A is a 16071 predecessor of B, and B is a successor of A. Edges are represented in 16072 GCC with the `edge' data type. Each `edge' acts as a link between two 16073 basic blocks: the `src' member of an edge points to the predecessor 16074 basic block of the `dest' basic block. The members `preds' and `succs' 16075 of the `basic_block' data type point to type-safe vectors of edges to 16076 the predecessors and successors of the block. 16077 16078 When walking the edges in an edge vector, "edge iterators" should be 16079 used. Edge iterators are constructed using the `edge_iterator' data 16080 structure and several methods are available to operate on them: 16081 16082 `ei_start' 16083 This function initializes an `edge_iterator' that points to the 16084 first edge in a vector of edges. 16085 16086 `ei_last' 16087 This function initializes an `edge_iterator' that points to the 16088 last edge in a vector of edges. 16089 16090 `ei_end_p' 16091 This predicate is `true' if an `edge_iterator' represents the last 16092 edge in an edge vector. 16093 16094 `ei_one_before_end_p' 16095 This predicate is `true' if an `edge_iterator' represents the 16096 second last edge in an edge vector. 16097 16098 `ei_next' 16099 This function takes a pointer to an `edge_iterator' and makes it 16100 point to the next edge in the sequence. 16101 16102 `ei_prev' 16103 This function takes a pointer to an `edge_iterator' and makes it 16104 point to the previous edge in the sequence. 16105 16106 `ei_edge' 16107 This function returns the `edge' currently pointed to by an 16108 `edge_iterator'. 16109 16110 `ei_safe_safe' 16111 This function returns the `edge' currently pointed to by an 16112 `edge_iterator', but returns `NULL' if the iterator is pointing at 16113 the end of the sequence. This function has been provided for 16114 existing code makes the assumption that a `NULL' edge indicates 16115 the end of the sequence. 16116 16117 16118 The convenience macro `FOR_EACH_EDGE' can be used to visit all of the 16119 edges in a sequence of predecessor or successor edges. It must not be 16120 used when an element might be removed during the traversal, otherwise 16121 elements will be missed. Here is an example of how to use the macro: 16122 16123 edge e; 16124 edge_iterator ei; 16125 16126 FOR_EACH_EDGE (e, ei, bb->succs) 16127 { 16128 if (e->flags & EDGE_FALLTHRU) 16129 break; 16130 } 16131 16132 There are various reasons why control flow may transfer from one block 16133 to another. One possibility is that some instruction, for example a 16134 `CODE_LABEL', in a linearized instruction stream just always starts a 16135 new basic block. In this case a "fall-thru" edge links the basic block 16136 to the first following basic block. But there are several other 16137 reasons why edges may be created. The `flags' field of the `edge' data 16138 type is used to store information about the type of edge we are dealing 16139 with. Each edge is of one of the following types: 16140 16141 _jump_ 16142 No type flags are set for edges corresponding to jump instructions. 16143 These edges are used for unconditional or conditional jumps and in 16144 RTL also for table jumps. They are the easiest to manipulate as 16145 they may be freely redirected when the flow graph is not in SSA 16146 form. 16147 16148 _fall-thru_ 16149 Fall-thru edges are present in case where the basic block may 16150 continue execution to the following one without branching. These 16151 edges have the `EDGE_FALLTHRU' flag set. Unlike other types of 16152 edges, these edges must come into the basic block immediately 16153 following in the instruction stream. The function 16154 `force_nonfallthru' is available to insert an unconditional jump 16155 in the case that redirection is needed. Note that this may 16156 require creation of a new basic block. 16157 16158 _exception handling_ 16159 Exception handling edges represent possible control transfers from 16160 a trapping instruction to an exception handler. The definition of 16161 "trapping" varies. In C++, only function calls can throw, but for 16162 Java, exceptions like division by zero or segmentation fault are 16163 defined and thus each instruction possibly throwing this kind of 16164 exception needs to be handled as control flow instruction. 16165 Exception edges have the `EDGE_ABNORMAL' and `EDGE_EH' flags set. 16166 16167 When updating the instruction stream it is easy to change possibly 16168 trapping instruction to non-trapping, by simply removing the 16169 exception edge. The opposite conversion is difficult, but should 16170 not happen anyway. The edges can be eliminated via 16171 `purge_dead_edges' call. 16172 16173 In the RTL representation, the destination of an exception edge is 16174 specified by `REG_EH_REGION' note attached to the insn. In case 16175 of a trapping call the `EDGE_ABNORMAL_CALL' flag is set too. In 16176 the `tree' representation, this extra flag is not set. 16177 16178 In the RTL representation, the predicate `may_trap_p' may be used 16179 to check whether instruction still may trap or not. For the tree 16180 representation, the `tree_could_trap_p' predicate is available, 16181 but this predicate only checks for possible memory traps, as in 16182 dereferencing an invalid pointer location. 16183 16184 _sibling calls_ 16185 Sibling calls or tail calls terminate the function in a 16186 non-standard way and thus an edge to the exit must be present. 16187 `EDGE_SIBCALL' and `EDGE_ABNORMAL' are set in such case. These 16188 edges only exist in the RTL representation. 16189 16190 _computed jumps_ 16191 Computed jumps contain edges to all labels in the function 16192 referenced from the code. All those edges have `EDGE_ABNORMAL' 16193 flag set. The edges used to represent computed jumps often cause 16194 compile time performance problems, since functions consisting of 16195 many taken labels and many computed jumps may have _very_ dense 16196 flow graphs, so these edges need to be handled with special care. 16197 During the earlier stages of the compilation process, GCC tries to 16198 avoid such dense flow graphs by factoring computed jumps. For 16199 example, given the following series of jumps, 16200 16201 goto *x; 16202 [ ... ] 16203 16204 goto *x; 16205 [ ... ] 16206 16207 goto *x; 16208 [ ... ] 16209 16210 factoring the computed jumps results in the following code sequence 16211 which has a much simpler flow graph: 16212 16213 goto y; 16214 [ ... ] 16215 16216 goto y; 16217 [ ... ] 16218 16219 goto y; 16220 [ ... ] 16221 16222 y: 16223 goto *x; 16224 16225 However, the classic problem with this transformation is that it 16226 has a runtime cost in there resulting code: An extra jump. 16227 Therefore, the computed jumps are un-factored in the later passes 16228 of the compiler. Be aware of that when you work on passes in that 16229 area. There have been numerous examples already where the compile 16230 time for code with unfactored computed jumps caused some serious 16231 headaches. 16232 16233 _nonlocal goto handlers_ 16234 GCC allows nested functions to return into caller using a `goto' 16235 to a label passed to as an argument to the callee. The labels 16236 passed to nested functions contain special code to cleanup after 16237 function call. Such sections of code are referred to as "nonlocal 16238 goto receivers". If a function contains such nonlocal goto 16239 receivers, an edge from the call to the label is created with the 16240 `EDGE_ABNORMAL' and `EDGE_ABNORMAL_CALL' flags set. 16241 16242 _function entry points_ 16243 By definition, execution of function starts at basic block 0, so 16244 there is always an edge from the `ENTRY_BLOCK_PTR' to basic block 16245 0. There is no `tree' representation for alternate entry points at 16246 this moment. In RTL, alternate entry points are specified by 16247 `CODE_LABEL' with `LABEL_ALTERNATE_NAME' defined. This feature is 16248 currently used for multiple entry point prologues and is limited 16249 to post-reload passes only. This can be used by back-ends to emit 16250 alternate prologues for functions called from different contexts. 16251 In future full support for multiple entry functions defined by 16252 Fortran 90 needs to be implemented. 16253 16254 _function exits_ 16255 In the pre-reload representation a function terminates after the 16256 last instruction in the insn chain and no explicit return 16257 instructions are used. This corresponds to the fall-thru edge 16258 into exit block. After reload, optimal RTL epilogues are used 16259 that use explicit (conditional) return instructions that are 16260 represented by edges with no flags set. 16261 16262 16263 16264 File: gccint.info, Node: Profile information, Next: Maintaining the CFG, Prev: Edges, Up: Control Flow 16265 16266 15.3 Profile information 16267 ======================== 16268 16269 In many cases a compiler must make a choice whether to trade speed in 16270 one part of code for speed in another, or to trade code size for code 16271 speed. In such cases it is useful to know information about how often 16272 some given block will be executed. That is the purpose for maintaining 16273 profile within the flow graph. GCC can handle profile information 16274 obtained through "profile feedback", but it can also estimate branch 16275 probabilities based on statics and heuristics. 16276 16277 The feedback based profile is produced by compiling the program with 16278 instrumentation, executing it on a train run and reading the numbers of 16279 executions of basic blocks and edges back to the compiler while 16280 re-compiling the program to produce the final executable. This method 16281 provides very accurate information about where a program spends most of 16282 its time on the train run. Whether it matches the average run of 16283 course depends on the choice of train data set, but several studies 16284 have shown that the behavior of a program usually changes just 16285 marginally over different data sets. 16286 16287 When profile feedback is not available, the compiler may be asked to 16288 attempt to predict the behavior of each branch in the program using a 16289 set of heuristics (see `predict.def' for details) and compute estimated 16290 frequencies of each basic block by propagating the probabilities over 16291 the graph. 16292 16293 Each `basic_block' contains two integer fields to represent profile 16294 information: `frequency' and `count'. The `frequency' is an estimation 16295 how often is basic block executed within a function. It is represented 16296 as an integer scaled in the range from 0 to `BB_FREQ_BASE'. The most 16297 frequently executed basic block in function is initially set to 16298 `BB_FREQ_BASE' and the rest of frequencies are scaled accordingly. 16299 During optimization, the frequency of the most frequent basic block can 16300 both decrease (for instance by loop unrolling) or grow (for instance by 16301 cross-jumping optimization), so scaling sometimes has to be performed 16302 multiple times. 16303 16304 The `count' contains hard-counted numbers of execution measured during 16305 training runs and is nonzero only when profile feedback is available. 16306 This value is represented as the host's widest integer (typically a 64 16307 bit integer) of the special type `gcov_type'. 16308 16309 Most optimization passes can use only the frequency information of a 16310 basic block, but a few passes may want to know hard execution counts. 16311 The frequencies should always match the counts after scaling, however 16312 during updating of the profile information numerical error may 16313 accumulate into quite large errors. 16314 16315 Each edge also contains a branch probability field: an integer in the 16316 range from 0 to `REG_BR_PROB_BASE'. It represents probability of 16317 passing control from the end of the `src' basic block to the `dest' 16318 basic block, i.e. the probability that control will flow along this 16319 edge. The `EDGE_FREQUENCY' macro is available to compute how 16320 frequently a given edge is taken. There is a `count' field for each 16321 edge as well, representing same information as for a basic block. 16322 16323 The basic block frequencies are not represented in the instruction 16324 stream, but in the RTL representation the edge frequencies are 16325 represented for conditional jumps (via the `REG_BR_PROB' macro) since 16326 they are used when instructions are output to the assembly file and the 16327 flow graph is no longer maintained. 16328 16329 The probability that control flow arrives via a given edge to its 16330 destination basic block is called "reverse probability" and is not 16331 directly represented, but it may be easily computed from frequencies of 16332 basic blocks. 16333 16334 Updating profile information is a delicate task that can unfortunately 16335 not be easily integrated with the CFG manipulation API. Many of the 16336 functions and hooks to modify the CFG, such as 16337 `redirect_edge_and_branch', do not have enough information to easily 16338 update the profile, so updating it is in the majority of cases left up 16339 to the caller. It is difficult to uncover bugs in the profile updating 16340 code, because they manifest themselves only by producing worse code, 16341 and checking profile consistency is not possible because of numeric 16342 error accumulation. Hence special attention needs to be given to this 16343 issue in each pass that modifies the CFG. 16344 16345 It is important to point out that `REG_BR_PROB_BASE' and 16346 `BB_FREQ_BASE' are both set low enough to be possible to compute second 16347 power of any frequency or probability in the flow graph, it is not 16348 possible to even square the `count' field, as modern CPUs are fast 16349 enough to execute $2^32$ operations quickly. 16350 16351 16352 File: gccint.info, Node: Maintaining the CFG, Next: Liveness information, Prev: Profile information, Up: Control Flow 16353 16354 15.4 Maintaining the CFG 16355 ======================== 16356 16357 An important task of each compiler pass is to keep both the control 16358 flow graph and all profile information up-to-date. Reconstruction of 16359 the control flow graph after each pass is not an option, since it may be 16360 very expensive and lost profile information cannot be reconstructed at 16361 all. 16362 16363 GCC has two major intermediate representations, and both use the 16364 `basic_block' and `edge' data types to represent control flow. Both 16365 representations share as much of the CFG maintenance code as possible. 16366 For each representation, a set of "hooks" is defined so that each 16367 representation can provide its own implementation of CFG manipulation 16368 routines when necessary. These hooks are defined in `cfghooks.h'. 16369 There are hooks for almost all common CFG manipulations, including 16370 block splitting and merging, edge redirection and creating and deleting 16371 basic blocks. These hooks should provide everything you need to 16372 maintain and manipulate the CFG in both the RTL and `tree' 16373 representation. 16374 16375 At the moment, the basic block boundaries are maintained transparently 16376 when modifying instructions, so there rarely is a need to move them 16377 manually (such as in case someone wants to output instruction outside 16378 basic block explicitly). Often the CFG may be better viewed as 16379 integral part of instruction chain, than structure built on the top of 16380 it. However, in principle the control flow graph for the `tree' 16381 representation is _not_ an integral part of the representation, in that 16382 a function tree may be expanded without first building a flow graph 16383 for the `tree' representation at all. This happens when compiling 16384 without any `tree' optimization enabled. When the `tree' optimizations 16385 are enabled and the instruction stream is rewritten in SSA form, the 16386 CFG is very tightly coupled with the instruction stream. In 16387 particular, statement insertion and removal has to be done with care. 16388 In fact, the whole `tree' representation can not be easily used or 16389 maintained without proper maintenance of the CFG simultaneously. 16390 16391 In the RTL representation, each instruction has a `BLOCK_FOR_INSN' 16392 value that represents pointer to the basic block that contains the 16393 instruction. In the `tree' representation, the function `bb_for_stmt' 16394 returns a pointer to the basic block containing the queried statement. 16395 16396 When changes need to be applied to a function in its `tree' 16397 representation, "block statement iterators" should be used. These 16398 iterators provide an integrated abstraction of the flow graph and the 16399 instruction stream. Block statement iterators are constructed using 16400 the `block_stmt_iterator' data structure and several modifier are 16401 available, including the following: 16402 16403 `bsi_start' 16404 This function initializes a `block_stmt_iterator' that points to 16405 the first non-empty statement in a basic block. 16406 16407 `bsi_last' 16408 This function initializes a `block_stmt_iterator' that points to 16409 the last statement in a basic block. 16410 16411 `bsi_end_p' 16412 This predicate is `true' if a `block_stmt_iterator' represents the 16413 end of a basic block. 16414 16415 `bsi_next' 16416 This function takes a `block_stmt_iterator' and makes it point to 16417 its successor. 16418 16419 `bsi_prev' 16420 This function takes a `block_stmt_iterator' and makes it point to 16421 its predecessor. 16422 16423 `bsi_insert_after' 16424 This function inserts a statement after the `block_stmt_iterator' 16425 passed in. The final parameter determines whether the statement 16426 iterator is updated to point to the newly inserted statement, or 16427 left pointing to the original statement. 16428 16429 `bsi_insert_before' 16430 This function inserts a statement before the `block_stmt_iterator' 16431 passed in. The final parameter determines whether the statement 16432 iterator is updated to point to the newly inserted statement, or 16433 left pointing to the original statement. 16434 16435 `bsi_remove' 16436 This function removes the `block_stmt_iterator' passed in and 16437 rechains the remaining statements in a basic block, if any. 16438 16439 In the RTL representation, the macros `BB_HEAD' and `BB_END' may be 16440 used to get the head and end `rtx' of a basic block. No abstract 16441 iterators are defined for traversing the insn chain, but you can just 16442 use `NEXT_INSN' and `PREV_INSN' instead. See *Note Insns::. 16443 16444 Usually a code manipulating pass simplifies the instruction stream and 16445 the flow of control, possibly eliminating some edges. This may for 16446 example happen when a conditional jump is replaced with an 16447 unconditional jump, but also when simplifying possibly trapping 16448 instruction to non-trapping while compiling Java. Updating of edges is 16449 not transparent and each optimization pass is required to do so 16450 manually. However only few cases occur in practice. The pass may call 16451 `purge_dead_edges' on a given basic block to remove superfluous edges, 16452 if any. 16453 16454 Another common scenario is redirection of branch instructions, but 16455 this is best modeled as redirection of edges in the control flow graph 16456 and thus use of `redirect_edge_and_branch' is preferred over more low 16457 level functions, such as `redirect_jump' that operate on RTL chain 16458 only. The CFG hooks defined in `cfghooks.h' should provide the 16459 complete API required for manipulating and maintaining the CFG. 16460 16461 It is also possible that a pass has to insert control flow instruction 16462 into the middle of a basic block, thus creating an entry point in the 16463 middle of the basic block, which is impossible by definition: The block 16464 must be split to make sure it only has one entry point, i.e. the head 16465 of the basic block. The CFG hook `split_block' may be used when an 16466 instruction in the middle of a basic block has to become the target of 16467 a jump or branch instruction. 16468 16469 For a global optimizer, a common operation is to split edges in the 16470 flow graph and insert instructions on them. In the RTL representation, 16471 this can be easily done using the `insert_insn_on_edge' function that 16472 emits an instruction "on the edge", caching it for a later 16473 `commit_edge_insertions' call that will take care of moving the 16474 inserted instructions off the edge into the instruction stream 16475 contained in a basic block. This includes the creation of new basic 16476 blocks where needed. In the `tree' representation, the equivalent 16477 functions are `bsi_insert_on_edge' which inserts a block statement 16478 iterator on an edge, and `bsi_commit_edge_inserts' which flushes the 16479 instruction to actual instruction stream. 16480 16481 While debugging the optimization pass, an `verify_flow_info' function 16482 may be useful to find bugs in the control flow graph updating code. 16483 16484 Note that at present, the representation of control flow in the `tree' 16485 representation is discarded before expanding to RTL. Long term the CFG 16486 should be maintained and "expanded" to the RTL representation along 16487 with the function `tree' itself. 16488 16489 16490 File: gccint.info, Node: Liveness information, Prev: Maintaining the CFG, Up: Control Flow 16491 16492 15.5 Liveness information 16493 ========================= 16494 16495 Liveness information is useful to determine whether some register is 16496 "live" at given point of program, i.e. that it contains a value that 16497 may be used at a later point in the program. This information is used, 16498 for instance, during register allocation, as the pseudo registers only 16499 need to be assigned to a unique hard register or to a stack slot if 16500 they are live. The hard registers and stack slots may be freely reused 16501 for other values when a register is dead. 16502 16503 Liveness information is available in the back end starting with 16504 `pass_df_initialize' and ending with `pass_df_finish'. Three flavors 16505 of live analysis are available: With `LR', it is possible to determine 16506 at any point `P' in the function if the register may be used on some 16507 path from `P' to the end of the function. With `UR', it is possible to 16508 determine if there is a path from the beginning of the function to `P' 16509 that defines the variable. `LIVE' is the intersection of the `LR' and 16510 `UR' and a variable is live at `P' if there is both an assignment that 16511 reaches it from the beginning of the function and a uses that can be 16512 reached on some path from `P' to the end of the function. 16513 16514 In general `LIVE' is the most useful of the three. The macros 16515 `DF_[LR,UR,LIVE]_[IN,OUT]' can be used to access this information. The 16516 macros take a basic block number and return a bitmap that is indexed by 16517 the register number. This information is only guaranteed to be up to 16518 date after calls are made to `df_analyze'. See the file `df-core.c' 16519 for details on using the dataflow. 16520 16521 The liveness information is stored partly in the RTL instruction stream 16522 and partly in the flow graph. Local information is stored in the 16523 instruction stream: Each instruction may contain `REG_DEAD' notes 16524 representing that the value of a given register is no longer needed, or 16525 `REG_UNUSED' notes representing that the value computed by the 16526 instruction is never used. The second is useful for instructions 16527 computing multiple values at once. 16528 16529 16530 File: gccint.info, Node: Machine Desc, Next: Target Macros, Prev: Loop Analysis and Representation, Up: Top 16531 16532 16 Machine Descriptions 16533 *********************** 16534 16535 A machine description has two parts: a file of instruction patterns 16536 (`.md' file) and a C header file of macro definitions. 16537 16538 The `.md' file for a target machine contains a pattern for each 16539 instruction that the target machine supports (or at least each 16540 instruction that is worth telling the compiler about). It may also 16541 contain comments. A semicolon causes the rest of the line to be a 16542 comment, unless the semicolon is inside a quoted string. 16543 16544 See the next chapter for information on the C header file. 16545 16546 * Menu: 16547 16548 * Overview:: How the machine description is used. 16549 * Patterns:: How to write instruction patterns. 16550 * Example:: An explained example of a `define_insn' pattern. 16551 * RTL Template:: The RTL template defines what insns match a pattern. 16552 * Output Template:: The output template says how to make assembler code 16553 from such an insn. 16554 * Output Statement:: For more generality, write C code to output 16555 the assembler code. 16556 * Predicates:: Controlling what kinds of operands can be used 16557 for an insn. 16558 * Constraints:: Fine-tuning operand selection. 16559 * Standard Names:: Names mark patterns to use for code generation. 16560 * Pattern Ordering:: When the order of patterns makes a difference. 16561 * Dependent Patterns:: Having one pattern may make you need another. 16562 * Jump Patterns:: Special considerations for patterns for jump insns. 16563 * Looping Patterns:: How to define patterns for special looping insns. 16564 * Insn Canonicalizations::Canonicalization of Instructions 16565 * Expander Definitions::Generating a sequence of several RTL insns 16566 for a standard operation. 16567 * Insn Splitting:: Splitting Instructions into Multiple Instructions. 16568 * Including Patterns:: Including Patterns in Machine Descriptions. 16569 * Peephole Definitions::Defining machine-specific peephole optimizations. 16570 * Insn Attributes:: Specifying the value of attributes for generated insns. 16571 * Conditional Execution::Generating `define_insn' patterns for 16572 predication. 16573 * Constant Definitions::Defining symbolic constants that can be used in the 16574 md file. 16575 * Iterators:: Using iterators to generate patterns from a template. 16576 16577 16578 File: gccint.info, Node: Overview, Next: Patterns, Up: Machine Desc 16579 16580 16.1 Overview of How the Machine Description is Used 16581 ==================================================== 16582 16583 There are three main conversions that happen in the compiler: 16584 16585 1. The front end reads the source code and builds a parse tree. 16586 16587 2. The parse tree is used to generate an RTL insn list based on named 16588 instruction patterns. 16589 16590 3. The insn list is matched against the RTL templates to produce 16591 assembler code. 16592 16593 16594 For the generate pass, only the names of the insns matter, from either 16595 a named `define_insn' or a `define_expand'. The compiler will choose 16596 the pattern with the right name and apply the operands according to the 16597 documentation later in this chapter, without regard for the RTL 16598 template or operand constraints. Note that the names the compiler looks 16599 for are hard-coded in the compiler--it will ignore unnamed patterns and 16600 patterns with names it doesn't know about, but if you don't provide a 16601 named pattern it needs, it will abort. 16602 16603 If a `define_insn' is used, the template given is inserted into the 16604 insn list. If a `define_expand' is used, one of three things happens, 16605 based on the condition logic. The condition logic may manually create 16606 new insns for the insn list, say via `emit_insn()', and invoke `DONE'. 16607 For certain named patterns, it may invoke `FAIL' to tell the compiler 16608 to use an alternate way of performing that task. If it invokes neither 16609 `DONE' nor `FAIL', the template given in the pattern is inserted, as if 16610 the `define_expand' were a `define_insn'. 16611 16612 Once the insn list is generated, various optimization passes convert, 16613 replace, and rearrange the insns in the insn list. This is where the 16614 `define_split' and `define_peephole' patterns get used, for example. 16615 16616 Finally, the insn list's RTL is matched up with the RTL templates in 16617 the `define_insn' patterns, and those patterns are used to emit the 16618 final assembly code. For this purpose, each named `define_insn' acts 16619 like it's unnamed, since the names are ignored. 16620 16621 16622 File: gccint.info, Node: Patterns, Next: Example, Prev: Overview, Up: Machine Desc 16623 16624 16.2 Everything about Instruction Patterns 16625 ========================================== 16626 16627 Each instruction pattern contains an incomplete RTL expression, with 16628 pieces to be filled in later, operand constraints that restrict how the 16629 pieces can be filled in, and an output pattern or C code to generate 16630 the assembler output, all wrapped up in a `define_insn' expression. 16631 16632 A `define_insn' is an RTL expression containing four or five operands: 16633 16634 1. An optional name. The presence of a name indicate that this 16635 instruction pattern can perform a certain standard job for the 16636 RTL-generation pass of the compiler. This pass knows certain 16637 names and will use the instruction patterns with those names, if 16638 the names are defined in the machine description. 16639 16640 The absence of a name is indicated by writing an empty string 16641 where the name should go. Nameless instruction patterns are never 16642 used for generating RTL code, but they may permit several simpler 16643 insns to be combined later on. 16644 16645 Names that are not thus known and used in RTL-generation have no 16646 effect; they are equivalent to no name at all. 16647 16648 For the purpose of debugging the compiler, you may also specify a 16649 name beginning with the `*' character. Such a name is used only 16650 for identifying the instruction in RTL dumps; it is entirely 16651 equivalent to having a nameless pattern for all other purposes. 16652 16653 2. The "RTL template" (*note RTL Template::) is a vector of incomplete 16654 RTL expressions which show what the instruction should look like. 16655 It is incomplete because it may contain `match_operand', 16656 `match_operator', and `match_dup' expressions that stand for 16657 operands of the instruction. 16658 16659 If the vector has only one element, that element is the template 16660 for the instruction pattern. If the vector has multiple elements, 16661 then the instruction pattern is a `parallel' expression containing 16662 the elements described. 16663 16664 3. A condition. This is a string which contains a C expression that 16665 is the final test to decide whether an insn body matches this 16666 pattern. 16667 16668 For a named pattern, the condition (if present) may not depend on 16669 the data in the insn being matched, but only the 16670 target-machine-type flags. The compiler needs to test these 16671 conditions during initialization in order to learn exactly which 16672 named instructions are available in a particular run. 16673 16674 For nameless patterns, the condition is applied only when matching 16675 an individual insn, and only after the insn has matched the 16676 pattern's recognition template. The insn's operands may be found 16677 in the vector `operands'. For an insn where the condition has 16678 once matched, it can't be used to control register allocation, for 16679 example by excluding certain hard registers or hard register 16680 combinations. 16681 16682 4. The "output template": a string that says how to output matching 16683 insns as assembler code. `%' in this string specifies where to 16684 substitute the value of an operand. *Note Output Template::. 16685 16686 When simple substitution isn't general enough, you can specify a 16687 piece of C code to compute the output. *Note Output Statement::. 16688 16689 5. Optionally, a vector containing the values of attributes for insns 16690 matching this pattern. *Note Insn Attributes::. 16691 16692 16693 File: gccint.info, Node: Example, Next: RTL Template, Prev: Patterns, Up: Machine Desc 16694 16695 16.3 Example of `define_insn' 16696 ============================= 16697 16698 Here is an actual example of an instruction pattern, for the 16699 68000/68020. 16700 16701 (define_insn "tstsi" 16702 [(set (cc0) 16703 (match_operand:SI 0 "general_operand" "rm"))] 16704 "" 16705 "* 16706 { 16707 if (TARGET_68020 || ! ADDRESS_REG_P (operands[0])) 16708 return \"tstl %0\"; 16709 return \"cmpl #0,%0\"; 16710 }") 16711 16712 This can also be written using braced strings: 16713 16714 (define_insn "tstsi" 16715 [(set (cc0) 16716 (match_operand:SI 0 "general_operand" "rm"))] 16717 "" 16718 { 16719 if (TARGET_68020 || ! ADDRESS_REG_P (operands[0])) 16720 return "tstl %0"; 16721 return "cmpl #0,%0"; 16722 }) 16723 16724 This is an instruction that sets the condition codes based on the 16725 value of a general operand. It has no condition, so any insn whose RTL 16726 description has the form shown may be handled according to this 16727 pattern. The name `tstsi' means "test a `SImode' value" and tells the 16728 RTL generation pass that, when it is necessary to test such a value, an 16729 insn to do so can be constructed using this pattern. 16730 16731 The output control string is a piece of C code which chooses which 16732 output template to return based on the kind of operand and the specific 16733 type of CPU for which code is being generated. 16734 16735 `"rm"' is an operand constraint. Its meaning is explained below. 16736 16737 16738 File: gccint.info, Node: RTL Template, Next: Output Template, Prev: Example, Up: Machine Desc 16739 16740 16.4 RTL Template 16741 ================= 16742 16743 The RTL template is used to define which insns match the particular 16744 pattern and how to find their operands. For named patterns, the RTL 16745 template also says how to construct an insn from specified operands. 16746 16747 Construction involves substituting specified operands into a copy of 16748 the template. Matching involves determining the values that serve as 16749 the operands in the insn being matched. Both of these activities are 16750 controlled by special expression types that direct matching and 16751 substitution of the operands. 16752 16753 `(match_operand:M N PREDICATE CONSTRAINT)' 16754 This expression is a placeholder for operand number N of the insn. 16755 When constructing an insn, operand number N will be substituted 16756 at this point. When matching an insn, whatever appears at this 16757 position in the insn will be taken as operand number N; but it 16758 must satisfy PREDICATE or this instruction pattern will not match 16759 at all. 16760 16761 Operand numbers must be chosen consecutively counting from zero in 16762 each instruction pattern. There may be only one `match_operand' 16763 expression in the pattern for each operand number. Usually 16764 operands are numbered in the order of appearance in `match_operand' 16765 expressions. In the case of a `define_expand', any operand numbers 16766 used only in `match_dup' expressions have higher values than all 16767 other operand numbers. 16768 16769 PREDICATE is a string that is the name of a function that accepts 16770 two arguments, an expression and a machine mode. *Note 16771 Predicates::. During matching, the function will be called with 16772 the putative operand as the expression and M as the mode argument 16773 (if M is not specified, `VOIDmode' will be used, which normally 16774 causes PREDICATE to accept any mode). If it returns zero, this 16775 instruction pattern fails to match. PREDICATE may be an empty 16776 string; then it means no test is to be done on the operand, so 16777 anything which occurs in this position is valid. 16778 16779 Most of the time, PREDICATE will reject modes other than M--but 16780 not always. For example, the predicate `address_operand' uses M 16781 as the mode of memory ref that the address should be valid for. 16782 Many predicates accept `const_int' nodes even though their mode is 16783 `VOIDmode'. 16784 16785 CONSTRAINT controls reloading and the choice of the best register 16786 class to use for a value, as explained later (*note Constraints::). 16787 If the constraint would be an empty string, it can be omitted. 16788 16789 People are often unclear on the difference between the constraint 16790 and the predicate. The predicate helps decide whether a given 16791 insn matches the pattern. The constraint plays no role in this 16792 decision; instead, it controls various decisions in the case of an 16793 insn which does match. 16794 16795 `(match_scratch:M N CONSTRAINT)' 16796 This expression is also a placeholder for operand number N and 16797 indicates that operand must be a `scratch' or `reg' expression. 16798 16799 When matching patterns, this is equivalent to 16800 16801 (match_operand:M N "scratch_operand" PRED) 16802 16803 but, when generating RTL, it produces a (`scratch':M) expression. 16804 16805 If the last few expressions in a `parallel' are `clobber' 16806 expressions whose operands are either a hard register or 16807 `match_scratch', the combiner can add or delete them when 16808 necessary. *Note Side Effects::. 16809 16810 `(match_dup N)' 16811 This expression is also a placeholder for operand number N. It is 16812 used when the operand needs to appear more than once in the insn. 16813 16814 In construction, `match_dup' acts just like `match_operand': the 16815 operand is substituted into the insn being constructed. But in 16816 matching, `match_dup' behaves differently. It assumes that operand 16817 number N has already been determined by a `match_operand' 16818 appearing earlier in the recognition template, and it matches only 16819 an identical-looking expression. 16820 16821 Note that `match_dup' should not be used to tell the compiler that 16822 a particular register is being used for two operands (example: 16823 `add' that adds one register to another; the second register is 16824 both an input operand and the output operand). Use a matching 16825 constraint (*note Simple Constraints::) for those. `match_dup' is 16826 for the cases where one operand is used in two places in the 16827 template, such as an instruction that computes both a quotient and 16828 a remainder, where the opcode takes two input operands but the RTL 16829 template has to refer to each of those twice; once for the 16830 quotient pattern and once for the remainder pattern. 16831 16832 `(match_operator:M N PREDICATE [OPERANDS...])' 16833 This pattern is a kind of placeholder for a variable RTL expression 16834 code. 16835 16836 When constructing an insn, it stands for an RTL expression whose 16837 expression code is taken from that of operand N, and whose 16838 operands are constructed from the patterns OPERANDS. 16839 16840 When matching an expression, it matches an expression if the 16841 function PREDICATE returns nonzero on that expression _and_ the 16842 patterns OPERANDS match the operands of the expression. 16843 16844 Suppose that the function `commutative_operator' is defined as 16845 follows, to match any expression whose operator is one of the 16846 commutative arithmetic operators of RTL and whose mode is MODE: 16847 16848 int 16849 commutative_integer_operator (x, mode) 16850 rtx x; 16851 enum machine_mode mode; 16852 { 16853 enum rtx_code code = GET_CODE (x); 16854 if (GET_MODE (x) != mode) 16855 return 0; 16856 return (GET_RTX_CLASS (code) == RTX_COMM_ARITH 16857 || code == EQ || code == NE); 16858 } 16859 16860 Then the following pattern will match any RTL expression consisting 16861 of a commutative operator applied to two general operands: 16862 16863 (match_operator:SI 3 "commutative_operator" 16864 [(match_operand:SI 1 "general_operand" "g") 16865 (match_operand:SI 2 "general_operand" "g")]) 16866 16867 Here the vector `[OPERANDS...]' contains two patterns because the 16868 expressions to be matched all contain two operands. 16869 16870 When this pattern does match, the two operands of the commutative 16871 operator are recorded as operands 1 and 2 of the insn. (This is 16872 done by the two instances of `match_operand'.) Operand 3 of the 16873 insn will be the entire commutative expression: use `GET_CODE 16874 (operands[3])' to see which commutative operator was used. 16875 16876 The machine mode M of `match_operator' works like that of 16877 `match_operand': it is passed as the second argument to the 16878 predicate function, and that function is solely responsible for 16879 deciding whether the expression to be matched "has" that mode. 16880 16881 When constructing an insn, argument 3 of the gen-function will 16882 specify the operation (i.e. the expression code) for the 16883 expression to be made. It should be an RTL expression, whose 16884 expression code is copied into a new expression whose operands are 16885 arguments 1 and 2 of the gen-function. The subexpressions of 16886 argument 3 are not used; only its expression code matters. 16887 16888 When `match_operator' is used in a pattern for matching an insn, 16889 it usually best if the operand number of the `match_operator' is 16890 higher than that of the actual operands of the insn. This improves 16891 register allocation because the register allocator often looks at 16892 operands 1 and 2 of insns to see if it can do register tying. 16893 16894 There is no way to specify constraints in `match_operator'. The 16895 operand of the insn which corresponds to the `match_operator' 16896 never has any constraints because it is never reloaded as a whole. 16897 However, if parts of its OPERANDS are matched by `match_operand' 16898 patterns, those parts may have constraints of their own. 16899 16900 `(match_op_dup:M N[OPERANDS...])' 16901 Like `match_dup', except that it applies to operators instead of 16902 operands. When constructing an insn, operand number N will be 16903 substituted at this point. But in matching, `match_op_dup' behaves 16904 differently. It assumes that operand number N has already been 16905 determined by a `match_operator' appearing earlier in the 16906 recognition template, and it matches only an identical-looking 16907 expression. 16908 16909 `(match_parallel N PREDICATE [SUBPAT...])' 16910 This pattern is a placeholder for an insn that consists of a 16911 `parallel' expression with a variable number of elements. This 16912 expression should only appear at the top level of an insn pattern. 16913 16914 When constructing an insn, operand number N will be substituted at 16915 this point. When matching an insn, it matches if the body of the 16916 insn is a `parallel' expression with at least as many elements as 16917 the vector of SUBPAT expressions in the `match_parallel', if each 16918 SUBPAT matches the corresponding element of the `parallel', _and_ 16919 the function PREDICATE returns nonzero on the `parallel' that is 16920 the body of the insn. It is the responsibility of the predicate 16921 to validate elements of the `parallel' beyond those listed in the 16922 `match_parallel'. 16923 16924 A typical use of `match_parallel' is to match load and store 16925 multiple expressions, which can contain a variable number of 16926 elements in a `parallel'. For example, 16927 16928 (define_insn "" 16929 [(match_parallel 0 "load_multiple_operation" 16930 [(set (match_operand:SI 1 "gpc_reg_operand" "=r") 16931 (match_operand:SI 2 "memory_operand" "m")) 16932 (use (reg:SI 179)) 16933 (clobber (reg:SI 179))])] 16934 "" 16935 "loadm 0,0,%1,%2") 16936 16937 This example comes from `a29k.md'. The function 16938 `load_multiple_operation' is defined in `a29k.c' and checks that 16939 subsequent elements in the `parallel' are the same as the `set' in 16940 the pattern, except that they are referencing subsequent registers 16941 and memory locations. 16942 16943 An insn that matches this pattern might look like: 16944 16945 (parallel 16946 [(set (reg:SI 20) (mem:SI (reg:SI 100))) 16947 (use (reg:SI 179)) 16948 (clobber (reg:SI 179)) 16949 (set (reg:SI 21) 16950 (mem:SI (plus:SI (reg:SI 100) 16951 (const_int 4)))) 16952 (set (reg:SI 22) 16953 (mem:SI (plus:SI (reg:SI 100) 16954 (const_int 8))))]) 16955 16956 `(match_par_dup N [SUBPAT...])' 16957 Like `match_op_dup', but for `match_parallel' instead of 16958 `match_operator'. 16959 16960 16961 16962 File: gccint.info, Node: Output Template, Next: Output Statement, Prev: RTL Template, Up: Machine Desc 16963 16964 16.5 Output Templates and Operand Substitution 16965 ============================================== 16966 16967 The "output template" is a string which specifies how to output the 16968 assembler code for an instruction pattern. Most of the template is a 16969 fixed string which is output literally. The character `%' is used to 16970 specify where to substitute an operand; it can also be used to identify 16971 places where different variants of the assembler require different 16972 syntax. 16973 16974 In the simplest case, a `%' followed by a digit N says to output 16975 operand N at that point in the string. 16976 16977 `%' followed by a letter and a digit says to output an operand in an 16978 alternate fashion. Four letters have standard, built-in meanings 16979 described below. The machine description macro `PRINT_OPERAND' can 16980 define additional letters with nonstandard meanings. 16981 16982 `%cDIGIT' can be used to substitute an operand that is a constant 16983 value without the syntax that normally indicates an immediate operand. 16984 16985 `%nDIGIT' is like `%cDIGIT' except that the value of the constant is 16986 negated before printing. 16987 16988 `%aDIGIT' can be used to substitute an operand as if it were a memory 16989 reference, with the actual operand treated as the address. This may be 16990 useful when outputting a "load address" instruction, because often the 16991 assembler syntax for such an instruction requires you to write the 16992 operand as if it were a memory reference. 16993 16994 `%lDIGIT' is used to substitute a `label_ref' into a jump instruction. 16995 16996 `%=' outputs a number which is unique to each instruction in the 16997 entire compilation. This is useful for making local labels to be 16998 referred to more than once in a single template that generates multiple 16999 assembler instructions. 17000 17001 `%' followed by a punctuation character specifies a substitution that 17002 does not use an operand. Only one case is standard: `%%' outputs a `%' 17003 into the assembler code. Other nonstandard cases can be defined in the 17004 `PRINT_OPERAND' macro. You must also define which punctuation 17005 characters are valid with the `PRINT_OPERAND_PUNCT_VALID_P' macro. 17006 17007 The template may generate multiple assembler instructions. Write the 17008 text for the instructions, with `\;' between them. 17009 17010 When the RTL contains two operands which are required by constraint to 17011 match each other, the output template must refer only to the 17012 lower-numbered operand. Matching operands are not always identical, 17013 and the rest of the compiler arranges to put the proper RTL expression 17014 for printing into the lower-numbered operand. 17015 17016 One use of nonstandard letters or punctuation following `%' is to 17017 distinguish between different assembler languages for the same machine; 17018 for example, Motorola syntax versus MIT syntax for the 68000. Motorola 17019 syntax requires periods in most opcode names, while MIT syntax does 17020 not. For example, the opcode `movel' in MIT syntax is `move.l' in 17021 Motorola syntax. The same file of patterns is used for both kinds of 17022 output syntax, but the character sequence `%.' is used in each place 17023 where Motorola syntax wants a period. The `PRINT_OPERAND' macro for 17024 Motorola syntax defines the sequence to output a period; the macro for 17025 MIT syntax defines it to do nothing. 17026 17027 As a special case, a template consisting of the single character `#' 17028 instructs the compiler to first split the insn, and then output the 17029 resulting instructions separately. This helps eliminate redundancy in 17030 the output templates. If you have a `define_insn' that needs to emit 17031 multiple assembler instructions, and there is an matching `define_split' 17032 already defined, then you can simply use `#' as the output template 17033 instead of writing an output template that emits the multiple assembler 17034 instructions. 17035 17036 If the macro `ASSEMBLER_DIALECT' is defined, you can use construct of 17037 the form `{option0|option1|option2}' in the templates. These describe 17038 multiple variants of assembler language syntax. *Note Instruction 17039 Output::. 17040 17041 17042 File: gccint.info, Node: Output Statement, Next: Predicates, Prev: Output Template, Up: Machine Desc 17043 17044 16.6 C Statements for Assembler Output 17045 ====================================== 17046 17047 Often a single fixed template string cannot produce correct and 17048 efficient assembler code for all the cases that are recognized by a 17049 single instruction pattern. For example, the opcodes may depend on the 17050 kinds of operands; or some unfortunate combinations of operands may 17051 require extra machine instructions. 17052 17053 If the output control string starts with a `@', then it is actually a 17054 series of templates, each on a separate line. (Blank lines and leading 17055 spaces and tabs are ignored.) The templates correspond to the 17056 pattern's constraint alternatives (*note Multi-Alternative::). For 17057 example, if a target machine has a two-address add instruction `addr' 17058 to add into a register and another `addm' to add a register to memory, 17059 you might write this pattern: 17060 17061 (define_insn "addsi3" 17062 [(set (match_operand:SI 0 "general_operand" "=r,m") 17063 (plus:SI (match_operand:SI 1 "general_operand" "0,0") 17064 (match_operand:SI 2 "general_operand" "g,r")))] 17065 "" 17066 "@ 17067 addr %2,%0 17068 addm %2,%0") 17069 17070 If the output control string starts with a `*', then it is not an 17071 output template but rather a piece of C program that should compute a 17072 template. It should execute a `return' statement to return the 17073 template-string you want. Most such templates use C string literals, 17074 which require doublequote characters to delimit them. To include these 17075 doublequote characters in the string, prefix each one with `\'. 17076 17077 If the output control string is written as a brace block instead of a 17078 double-quoted string, it is automatically assumed to be C code. In that 17079 case, it is not necessary to put in a leading asterisk, or to escape the 17080 doublequotes surrounding C string literals. 17081 17082 The operands may be found in the array `operands', whose C data type 17083 is `rtx []'. 17084 17085 It is very common to select different ways of generating assembler code 17086 based on whether an immediate operand is within a certain range. Be 17087 careful when doing this, because the result of `INTVAL' is an integer 17088 on the host machine. If the host machine has more bits in an `int' 17089 than the target machine has in the mode in which the constant will be 17090 used, then some of the bits you get from `INTVAL' will be superfluous. 17091 For proper results, you must carefully disregard the values of those 17092 bits. 17093 17094 It is possible to output an assembler instruction and then go on to 17095 output or compute more of them, using the subroutine `output_asm_insn'. 17096 This receives two arguments: a template-string and a vector of 17097 operands. The vector may be `operands', or it may be another array of 17098 `rtx' that you declare locally and initialize yourself. 17099 17100 When an insn pattern has multiple alternatives in its constraints, 17101 often the appearance of the assembler code is determined mostly by 17102 which alternative was matched. When this is so, the C code can test 17103 the variable `which_alternative', which is the ordinal number of the 17104 alternative that was actually satisfied (0 for the first, 1 for the 17105 second alternative, etc.). 17106 17107 For example, suppose there are two opcodes for storing zero, `clrreg' 17108 for registers and `clrmem' for memory locations. Here is how a pattern 17109 could use `which_alternative' to choose between them: 17110 17111 (define_insn "" 17112 [(set (match_operand:SI 0 "general_operand" "=r,m") 17113 (const_int 0))] 17114 "" 17115 { 17116 return (which_alternative == 0 17117 ? "clrreg %0" : "clrmem %0"); 17118 }) 17119 17120 The example above, where the assembler code to generate was _solely_ 17121 determined by the alternative, could also have been specified as 17122 follows, having the output control string start with a `@': 17123 17124 (define_insn "" 17125 [(set (match_operand:SI 0 "general_operand" "=r,m") 17126 (const_int 0))] 17127 "" 17128 "@ 17129 clrreg %0 17130 clrmem %0") 17131 17132 17133 File: gccint.info, Node: Predicates, Next: Constraints, Prev: Output Statement, Up: Machine Desc 17134 17135 16.7 Predicates 17136 =============== 17137 17138 A predicate determines whether a `match_operand' or `match_operator' 17139 expression matches, and therefore whether the surrounding instruction 17140 pattern will be used for that combination of operands. GCC has a 17141 number of machine-independent predicates, and you can define 17142 machine-specific predicates as needed. By convention, predicates used 17143 with `match_operand' have names that end in `_operand', and those used 17144 with `match_operator' have names that end in `_operator'. 17145 17146 All predicates are Boolean functions (in the mathematical sense) of 17147 two arguments: the RTL expression that is being considered at that 17148 position in the instruction pattern, and the machine mode that the 17149 `match_operand' or `match_operator' specifies. In this section, the 17150 first argument is called OP and the second argument MODE. Predicates 17151 can be called from C as ordinary two-argument functions; this can be 17152 useful in output templates or other machine-specific code. 17153 17154 Operand predicates can allow operands that are not actually acceptable 17155 to the hardware, as long as the constraints give reload the ability to 17156 fix them up (*note Constraints::). However, GCC will usually generate 17157 better code if the predicates specify the requirements of the machine 17158 instructions as closely as possible. Reload cannot fix up operands 17159 that must be constants ("immediate operands"); you must use a predicate 17160 that allows only constants, or else enforce the requirement in the 17161 extra condition. 17162 17163 Most predicates handle their MODE argument in a uniform manner. If 17164 MODE is `VOIDmode' (unspecified), then OP can have any mode. If MODE 17165 is anything else, then OP must have the same mode, unless OP is a 17166 `CONST_INT' or integer `CONST_DOUBLE'. These RTL expressions always 17167 have `VOIDmode', so it would be counterproductive to check that their 17168 mode matches. Instead, predicates that accept `CONST_INT' and/or 17169 integer `CONST_DOUBLE' check that the value stored in the constant will 17170 fit in the requested mode. 17171 17172 Predicates with this behavior are called "normal". `genrecog' can 17173 optimize the instruction recognizer based on knowledge of how normal 17174 predicates treat modes. It can also diagnose certain kinds of common 17175 errors in the use of normal predicates; for instance, it is almost 17176 always an error to use a normal predicate without specifying a mode. 17177 17178 Predicates that do something different with their MODE argument are 17179 called "special". The generic predicates `address_operand' and 17180 `pmode_register_operand' are special predicates. `genrecog' does not 17181 do any optimizations or diagnosis when special predicates are used. 17182 17183 * Menu: 17184 17185 * Machine-Independent Predicates:: Predicates available to all back ends. 17186 * Defining Predicates:: How to write machine-specific predicate 17187 functions. 17188 17189 17190 File: gccint.info, Node: Machine-Independent Predicates, Next: Defining Predicates, Up: Predicates 17191 17192 16.7.1 Machine-Independent Predicates 17193 ------------------------------------- 17194 17195 These are the generic predicates available to all back ends. They are 17196 defined in `recog.c'. The first category of predicates allow only 17197 constant, or "immediate", operands. 17198 17199 -- Function: immediate_operand 17200 This predicate allows any sort of constant that fits in MODE. It 17201 is an appropriate choice for instructions that take operands that 17202 must be constant. 17203 17204 -- Function: const_int_operand 17205 This predicate allows any `CONST_INT' expression that fits in 17206 MODE. It is an appropriate choice for an immediate operand that 17207 does not allow a symbol or label. 17208 17209 -- Function: const_double_operand 17210 This predicate accepts any `CONST_DOUBLE' expression that has 17211 exactly MODE. If MODE is `VOIDmode', it will also accept 17212 `CONST_INT'. It is intended for immediate floating point 17213 constants. 17214 17215 The second category of predicates allow only some kind of machine 17216 register. 17217 17218 -- Function: register_operand 17219 This predicate allows any `REG' or `SUBREG' expression that is 17220 valid for MODE. It is often suitable for arithmetic instruction 17221 operands on a RISC machine. 17222 17223 -- Function: pmode_register_operand 17224 This is a slight variant on `register_operand' which works around 17225 a limitation in the machine-description reader. 17226 17227 (match_operand N "pmode_register_operand" CONSTRAINT) 17228 17229 means exactly what 17230 17231 (match_operand:P N "register_operand" CONSTRAINT) 17232 17233 would mean, if the machine-description reader accepted `:P' mode 17234 suffixes. Unfortunately, it cannot, because `Pmode' is an alias 17235 for some other mode, and might vary with machine-specific options. 17236 *Note Misc::. 17237 17238 -- Function: scratch_operand 17239 This predicate allows hard registers and `SCRATCH' expressions, 17240 but not pseudo-registers. It is used internally by 17241 `match_scratch'; it should not be used directly. 17242 17243 The third category of predicates allow only some kind of memory 17244 reference. 17245 17246 -- Function: memory_operand 17247 This predicate allows any valid reference to a quantity of mode 17248 MODE in memory, as determined by the weak form of 17249 `GO_IF_LEGITIMATE_ADDRESS' (*note Addressing Modes::). 17250 17251 -- Function: address_operand 17252 This predicate is a little unusual; it allows any operand that is a 17253 valid expression for the _address_ of a quantity of mode MODE, 17254 again determined by the weak form of `GO_IF_LEGITIMATE_ADDRESS'. 17255 To first order, if `(mem:MODE (EXP))' is acceptable to 17256 `memory_operand', then EXP is acceptable to `address_operand'. 17257 Note that EXP does not necessarily have the mode MODE. 17258 17259 -- Function: indirect_operand 17260 This is a stricter form of `memory_operand' which allows only 17261 memory references with a `general_operand' as the address 17262 expression. New uses of this predicate are discouraged, because 17263 `general_operand' is very permissive, so it's hard to tell what an 17264 `indirect_operand' does or does not allow. If a target has 17265 different requirements for memory operands for different 17266 instructions, it is better to define target-specific predicates 17267 which enforce the hardware's requirements explicitly. 17268 17269 -- Function: push_operand 17270 This predicate allows a memory reference suitable for pushing a 17271 value onto the stack. This will be a `MEM' which refers to 17272 `stack_pointer_rtx', with a side-effect in its address expression 17273 (*note Incdec::); which one is determined by the `STACK_PUSH_CODE' 17274 macro (*note Frame Layout::). 17275 17276 -- Function: pop_operand 17277 This predicate allows a memory reference suitable for popping a 17278 value off the stack. Again, this will be a `MEM' referring to 17279 `stack_pointer_rtx', with a side-effect in its address expression. 17280 However, this time `STACK_POP_CODE' is expected. 17281 17282 The fourth category of predicates allow some combination of the above 17283 operands. 17284 17285 -- Function: nonmemory_operand 17286 This predicate allows any immediate or register operand valid for 17287 MODE. 17288 17289 -- Function: nonimmediate_operand 17290 This predicate allows any register or memory operand valid for 17291 MODE. 17292 17293 -- Function: general_operand 17294 This predicate allows any immediate, register, or memory operand 17295 valid for MODE. 17296 17297 Finally, there is one generic operator predicate. 17298 17299 -- Function: comparison_operator 17300 This predicate matches any expression which performs an arithmetic 17301 comparison in MODE; that is, `COMPARISON_P' is true for the 17302 expression code. 17303 17304 17305 File: gccint.info, Node: Defining Predicates, Prev: Machine-Independent Predicates, Up: Predicates 17306 17307 16.7.2 Defining Machine-Specific Predicates 17308 ------------------------------------------- 17309 17310 Many machines have requirements for their operands that cannot be 17311 expressed precisely using the generic predicates. You can define 17312 additional predicates using `define_predicate' and 17313 `define_special_predicate' expressions. These expressions have three 17314 operands: 17315 17316 * The name of the predicate, as it will be referred to in 17317 `match_operand' or `match_operator' expressions. 17318 17319 * An RTL expression which evaluates to true if the predicate allows 17320 the operand OP, false if it does not. This expression can only use 17321 the following RTL codes: 17322 17323 `MATCH_OPERAND' 17324 When written inside a predicate expression, a `MATCH_OPERAND' 17325 expression evaluates to true if the predicate it names would 17326 allow OP. The operand number and constraint are ignored. 17327 Due to limitations in `genrecog', you can only refer to 17328 generic predicates and predicates that have already been 17329 defined. 17330 17331 `MATCH_CODE' 17332 This expression evaluates to true if OP or a specified 17333 subexpression of OP has one of a given list of RTX codes. 17334 17335 The first operand of this expression is a string constant 17336 containing a comma-separated list of RTX code names (in lower 17337 case). These are the codes for which the `MATCH_CODE' will 17338 be true. 17339 17340 The second operand is a string constant which indicates what 17341 subexpression of OP to examine. If it is absent or the empty 17342 string, OP itself is examined. Otherwise, the string constant 17343 must be a sequence of digits and/or lowercase letters. Each 17344 character indicates a subexpression to extract from the 17345 current expression; for the first character this is OP, for 17346 the second and subsequent characters it is the result of the 17347 previous character. A digit N extracts `XEXP (E, N)'; a 17348 letter L extracts `XVECEXP (E, 0, N)' where N is the 17349 alphabetic ordinal of L (0 for `a', 1 for 'b', and so on). 17350 The `MATCH_CODE' then examines the RTX code of the 17351 subexpression extracted by the complete string. It is not 17352 possible to extract components of an `rtvec' that is not at 17353 position 0 within its RTX object. 17354 17355 `MATCH_TEST' 17356 This expression has one operand, a string constant containing 17357 a C expression. The predicate's arguments, OP and MODE, are 17358 available with those names in the C expression. The 17359 `MATCH_TEST' evaluates to true if the C expression evaluates 17360 to a nonzero value. `MATCH_TEST' expressions must not have 17361 side effects. 17362 17363 `AND' 17364 `IOR' 17365 `NOT' 17366 `IF_THEN_ELSE' 17367 The basic `MATCH_' expressions can be combined using these 17368 logical operators, which have the semantics of the C operators 17369 `&&', `||', `!', and `? :' respectively. As in Common Lisp, 17370 you may give an `AND' or `IOR' expression an arbitrary number 17371 of arguments; this has exactly the same effect as writing a 17372 chain of two-argument `AND' or `IOR' expressions. 17373 17374 * An optional block of C code, which should execute `return true' if 17375 the predicate is found to match and `return false' if it does not. 17376 It must not have any side effects. The predicate arguments, OP 17377 and MODE, are available with those names. 17378 17379 If a code block is present in a predicate definition, then the RTL 17380 expression must evaluate to true _and_ the code block must execute 17381 `return true' for the predicate to allow the operand. The RTL 17382 expression is evaluated first; do not re-check anything in the 17383 code block that was checked in the RTL expression. 17384 17385 The program `genrecog' scans `define_predicate' and 17386 `define_special_predicate' expressions to determine which RTX codes are 17387 possibly allowed. You should always make this explicit in the RTL 17388 predicate expression, using `MATCH_OPERAND' and `MATCH_CODE'. 17389 17390 Here is an example of a simple predicate definition, from the IA64 17391 machine description: 17392 17393 ;; True if OP is a `SYMBOL_REF' which refers to the sdata section. 17394 (define_predicate "small_addr_symbolic_operand" 17395 (and (match_code "symbol_ref") 17396 (match_test "SYMBOL_REF_SMALL_ADDR_P (op)"))) 17397 17398 And here is another, showing the use of the C block. 17399 17400 ;; True if OP is a register operand that is (or could be) a GR reg. 17401 (define_predicate "gr_register_operand" 17402 (match_operand 0 "register_operand") 17403 { 17404 unsigned int regno; 17405 if (GET_CODE (op) == SUBREG) 17406 op = SUBREG_REG (op); 17407 17408 regno = REGNO (op); 17409 return (regno >= FIRST_PSEUDO_REGISTER || GENERAL_REGNO_P (regno)); 17410 }) 17411 17412 Predicates written with `define_predicate' automatically include a 17413 test that MODE is `VOIDmode', or OP has the same mode as MODE, or OP is 17414 a `CONST_INT' or `CONST_DOUBLE'. They do _not_ check specifically for 17415 integer `CONST_DOUBLE', nor do they test that the value of either kind 17416 of constant fits in the requested mode. This is because 17417 target-specific predicates that take constants usually have to do more 17418 stringent value checks anyway. If you need the exact same treatment of 17419 `CONST_INT' or `CONST_DOUBLE' that the generic predicates provide, use 17420 a `MATCH_OPERAND' subexpression to call `const_int_operand', 17421 `const_double_operand', or `immediate_operand'. 17422 17423 Predicates written with `define_special_predicate' do not get any 17424 automatic mode checks, and are treated as having special mode handling 17425 by `genrecog'. 17426 17427 The program `genpreds' is responsible for generating code to test 17428 predicates. It also writes a header file containing function 17429 declarations for all machine-specific predicates. It is not necessary 17430 to declare these predicates in `CPU-protos.h'. 17431 17432 17433 File: gccint.info, Node: Constraints, Next: Standard Names, Prev: Predicates, Up: Machine Desc 17434 17435 16.8 Operand Constraints 17436 ======================== 17437 17438 Each `match_operand' in an instruction pattern can specify constraints 17439 for the operands allowed. The constraints allow you to fine-tune 17440 matching within the set of operands allowed by the predicate. 17441 17442 Constraints can say whether an operand may be in a register, and which 17443 kinds of register; whether the operand can be a memory reference, and 17444 which kinds of address; whether the operand may be an immediate 17445 constant, and which possible values it may have. Constraints can also 17446 require two operands to match. 17447 17448 * Menu: 17449 17450 * Simple Constraints:: Basic use of constraints. 17451 * Multi-Alternative:: When an insn has two alternative constraint-patterns. 17452 * Class Preferences:: Constraints guide which hard register to put things in. 17453 * Modifiers:: More precise control over effects of constraints. 17454 * Disable Insn Alternatives:: Disable insn alternatives using the `enabled' attribute. 17455 * Machine Constraints:: Existing constraints for some particular machines. 17456 * Define Constraints:: How to define machine-specific constraints. 17457 * C Constraint Interface:: How to test constraints from C code. 17458 17459 17460 File: gccint.info, Node: Simple Constraints, Next: Multi-Alternative, Up: Constraints 17461 17462 16.8.1 Simple Constraints 17463 ------------------------- 17464 17465 The simplest kind of constraint is a string full of letters, each of 17466 which describes one kind of operand that is permitted. Here are the 17467 letters that are allowed: 17468 17469 whitespace 17470 Whitespace characters are ignored and can be inserted at any 17471 position except the first. This enables each alternative for 17472 different operands to be visually aligned in the machine 17473 description even if they have different number of constraints and 17474 modifiers. 17475 17476 `m' 17477 A memory operand is allowed, with any kind of address that the 17478 machine supports in general. Note that the letter used for the 17479 general memory constraint can be re-defined by a back end using 17480 the `TARGET_MEM_CONSTRAINT' macro. 17481 17482 `o' 17483 A memory operand is allowed, but only if the address is 17484 "offsettable". This means that adding a small integer (actually, 17485 the width in bytes of the operand, as determined by its machine 17486 mode) may be added to the address and the result is also a valid 17487 memory address. 17488 17489 For example, an address which is constant is offsettable; so is an 17490 address that is the sum of a register and a constant (as long as a 17491 slightly larger constant is also within the range of 17492 address-offsets supported by the machine); but an autoincrement or 17493 autodecrement address is not offsettable. More complicated 17494 indirect/indexed addresses may or may not be offsettable depending 17495 on the other addressing modes that the machine supports. 17496 17497 Note that in an output operand which can be matched by another 17498 operand, the constraint letter `o' is valid only when accompanied 17499 by both `<' (if the target machine has predecrement addressing) 17500 and `>' (if the target machine has preincrement addressing). 17501 17502 `V' 17503 A memory operand that is not offsettable. In other words, 17504 anything that would fit the `m' constraint but not the `o' 17505 constraint. 17506 17507 `<' 17508 A memory operand with autodecrement addressing (either 17509 predecrement or postdecrement) is allowed. 17510 17511 `>' 17512 A memory operand with autoincrement addressing (either 17513 preincrement or postincrement) is allowed. 17514 17515 `r' 17516 A register operand is allowed provided that it is in a general 17517 register. 17518 17519 `i' 17520 An immediate integer operand (one with constant value) is allowed. 17521 This includes symbolic constants whose values will be known only at 17522 assembly time or later. 17523 17524 `n' 17525 An immediate integer operand with a known numeric value is allowed. 17526 Many systems cannot support assembly-time constants for operands 17527 less than a word wide. Constraints for these operands should use 17528 `n' rather than `i'. 17529 17530 `I', `J', `K', ... `P' 17531 Other letters in the range `I' through `P' may be defined in a 17532 machine-dependent fashion to permit immediate integer operands with 17533 explicit integer values in specified ranges. For example, on the 17534 68000, `I' is defined to stand for the range of values 1 to 8. 17535 This is the range permitted as a shift count in the shift 17536 instructions. 17537 17538 `E' 17539 An immediate floating operand (expression code `const_double') is 17540 allowed, but only if the target floating point format is the same 17541 as that of the host machine (on which the compiler is running). 17542 17543 `F' 17544 An immediate floating operand (expression code `const_double' or 17545 `const_vector') is allowed. 17546 17547 `G', `H' 17548 `G' and `H' may be defined in a machine-dependent fashion to 17549 permit immediate floating operands in particular ranges of values. 17550 17551 `s' 17552 An immediate integer operand whose value is not an explicit 17553 integer is allowed. 17554 17555 This might appear strange; if an insn allows a constant operand 17556 with a value not known at compile time, it certainly must allow 17557 any known value. So why use `s' instead of `i'? Sometimes it 17558 allows better code to be generated. 17559 17560 For example, on the 68000 in a fullword instruction it is possible 17561 to use an immediate operand; but if the immediate value is between 17562 -128 and 127, better code results from loading the value into a 17563 register and using the register. This is because the load into 17564 the register can be done with a `moveq' instruction. We arrange 17565 for this to happen by defining the letter `K' to mean "any integer 17566 outside the range -128 to 127", and then specifying `Ks' in the 17567 operand constraints. 17568 17569 `g' 17570 Any register, memory or immediate integer operand is allowed, 17571 except for registers that are not general registers. 17572 17573 `X' 17574 Any operand whatsoever is allowed, even if it does not satisfy 17575 `general_operand'. This is normally used in the constraint of a 17576 `match_scratch' when certain alternatives will not actually 17577 require a scratch register. 17578 17579 `0', `1', `2', ... `9' 17580 An operand that matches the specified operand number is allowed. 17581 If a digit is used together with letters within the same 17582 alternative, the digit should come last. 17583 17584 This number is allowed to be more than a single digit. If multiple 17585 digits are encountered consecutively, they are interpreted as a 17586 single decimal integer. There is scant chance for ambiguity, 17587 since to-date it has never been desirable that `10' be interpreted 17588 as matching either operand 1 _or_ operand 0. Should this be 17589 desired, one can use multiple alternatives instead. 17590 17591 This is called a "matching constraint" and what it really means is 17592 that the assembler has only a single operand that fills two roles 17593 considered separate in the RTL insn. For example, an add insn has 17594 two input operands and one output operand in the RTL, but on most 17595 CISC machines an add instruction really has only two operands, one 17596 of them an input-output operand: 17597 17598 addl #35,r12 17599 17600 Matching constraints are used in these circumstances. More 17601 precisely, the two operands that match must include one input-only 17602 operand and one output-only operand. Moreover, the digit must be a 17603 smaller number than the number of the operand that uses it in the 17604 constraint. 17605 17606 For operands to match in a particular case usually means that they 17607 are identical-looking RTL expressions. But in a few special cases 17608 specific kinds of dissimilarity are allowed. For example, `*x' as 17609 an input operand will match `*x++' as an output operand. For 17610 proper results in such cases, the output template should always 17611 use the output-operand's number when printing the operand. 17612 17613 `p' 17614 An operand that is a valid memory address is allowed. This is for 17615 "load address" and "push address" instructions. 17616 17617 `p' in the constraint must be accompanied by `address_operand' as 17618 the predicate in the `match_operand'. This predicate interprets 17619 the mode specified in the `match_operand' as the mode of the memory 17620 reference for which the address would be valid. 17621 17622 OTHER-LETTERS 17623 Other letters can be defined in machine-dependent fashion to stand 17624 for particular classes of registers or other arbitrary operand 17625 types. `d', `a' and `f' are defined on the 68000/68020 to stand 17626 for data, address and floating point registers. 17627 17628 In order to have valid assembler code, each operand must satisfy its 17629 constraint. But a failure to do so does not prevent the pattern from 17630 applying to an insn. Instead, it directs the compiler to modify the 17631 code so that the constraint will be satisfied. Usually this is done by 17632 copying an operand into a register. 17633 17634 Contrast, therefore, the two instruction patterns that follow: 17635 17636 (define_insn "" 17637 [(set (match_operand:SI 0 "general_operand" "=r") 17638 (plus:SI (match_dup 0) 17639 (match_operand:SI 1 "general_operand" "r")))] 17640 "" 17641 "...") 17642 17643 which has two operands, one of which must appear in two places, and 17644 17645 (define_insn "" 17646 [(set (match_operand:SI 0 "general_operand" "=r") 17647 (plus:SI (match_operand:SI 1 "general_operand" "0") 17648 (match_operand:SI 2 "general_operand" "r")))] 17649 "" 17650 "...") 17651 17652 which has three operands, two of which are required by a constraint to 17653 be identical. If we are considering an insn of the form 17654 17655 (insn N PREV NEXT 17656 (set (reg:SI 3) 17657 (plus:SI (reg:SI 6) (reg:SI 109))) 17658 ...) 17659 17660 the first pattern would not apply at all, because this insn does not 17661 contain two identical subexpressions in the right place. The pattern 17662 would say, "That does not look like an add instruction; try other 17663 patterns". The second pattern would say, "Yes, that's an add 17664 instruction, but there is something wrong with it". It would direct 17665 the reload pass of the compiler to generate additional insns to make 17666 the constraint true. The results might look like this: 17667 17668 (insn N2 PREV N 17669 (set (reg:SI 3) (reg:SI 6)) 17670 ...) 17671 17672 (insn N N2 NEXT 17673 (set (reg:SI 3) 17674 (plus:SI (reg:SI 3) (reg:SI 109))) 17675 ...) 17676 17677 It is up to you to make sure that each operand, in each pattern, has 17678 constraints that can handle any RTL expression that could be present for 17679 that operand. (When multiple alternatives are in use, each pattern 17680 must, for each possible combination of operand expressions, have at 17681 least one alternative which can handle that combination of operands.) 17682 The constraints don't need to _allow_ any possible operand--when this is 17683 the case, they do not constrain--but they must at least point the way to 17684 reloading any possible operand so that it will fit. 17685 17686 * If the constraint accepts whatever operands the predicate permits, 17687 there is no problem: reloading is never necessary for this operand. 17688 17689 For example, an operand whose constraints permit everything except 17690 registers is safe provided its predicate rejects registers. 17691 17692 An operand whose predicate accepts only constant values is safe 17693 provided its constraints include the letter `i'. If any possible 17694 constant value is accepted, then nothing less than `i' will do; if 17695 the predicate is more selective, then the constraints may also be 17696 more selective. 17697 17698 * Any operand expression can be reloaded by copying it into a 17699 register. So if an operand's constraints allow some kind of 17700 register, it is certain to be safe. It need not permit all 17701 classes of registers; the compiler knows how to copy a register 17702 into another register of the proper class in order to make an 17703 instruction valid. 17704 17705 * A nonoffsettable memory reference can be reloaded by copying the 17706 address into a register. So if the constraint uses the letter 17707 `o', all memory references are taken care of. 17708 17709 * A constant operand can be reloaded by allocating space in memory to 17710 hold it as preinitialized data. Then the memory reference can be 17711 used in place of the constant. So if the constraint uses the 17712 letters `o' or `m', constant operands are not a problem. 17713 17714 * If the constraint permits a constant and a pseudo register used in 17715 an insn was not allocated to a hard register and is equivalent to 17716 a constant, the register will be replaced with the constant. If 17717 the predicate does not permit a constant and the insn is 17718 re-recognized for some reason, the compiler will crash. Thus the 17719 predicate must always recognize any objects allowed by the 17720 constraint. 17721 17722 If the operand's predicate can recognize registers, but the constraint 17723 does not permit them, it can make the compiler crash. When this 17724 operand happens to be a register, the reload pass will be stymied, 17725 because it does not know how to copy a register temporarily into memory. 17726 17727 If the predicate accepts a unary operator, the constraint applies to 17728 the operand. For example, the MIPS processor at ISA level 3 supports an 17729 instruction which adds two registers in `SImode' to produce a `DImode' 17730 result, but only if the registers are correctly sign extended. This 17731 predicate for the input operands accepts a `sign_extend' of an `SImode' 17732 register. Write the constraint to indicate the type of register that 17733 is required for the operand of the `sign_extend'. 17734 17735 17736 File: gccint.info, Node: Multi-Alternative, Next: Class Preferences, Prev: Simple Constraints, Up: Constraints 17737 17738 16.8.2 Multiple Alternative Constraints 17739 --------------------------------------- 17740 17741 Sometimes a single instruction has multiple alternative sets of possible 17742 operands. For example, on the 68000, a logical-or instruction can 17743 combine register or an immediate value into memory, or it can combine 17744 any kind of operand into a register; but it cannot combine one memory 17745 location into another. 17746 17747 These constraints are represented as multiple alternatives. An 17748 alternative can be described by a series of letters for each operand. 17749 The overall constraint for an operand is made from the letters for this 17750 operand from the first alternative, a comma, the letters for this 17751 operand from the second alternative, a comma, and so on until the last 17752 alternative. Here is how it is done for fullword logical-or on the 17753 68000: 17754 17755 (define_insn "iorsi3" 17756 [(set (match_operand:SI 0 "general_operand" "=m,d") 17757 (ior:SI (match_operand:SI 1 "general_operand" "%0,0") 17758 (match_operand:SI 2 "general_operand" "dKs,dmKs")))] 17759 ...) 17760 17761 The first alternative has `m' (memory) for operand 0, `0' for operand 17762 1 (meaning it must match operand 0), and `dKs' for operand 2. The 17763 second alternative has `d' (data register) for operand 0, `0' for 17764 operand 1, and `dmKs' for operand 2. The `=' and `%' in the 17765 constraints apply to all the alternatives; their meaning is explained 17766 in the next section (*note Class Preferences::). 17767 17768 If all the operands fit any one alternative, the instruction is valid. 17769 Otherwise, for each alternative, the compiler counts how many 17770 instructions must be added to copy the operands so that that 17771 alternative applies. The alternative requiring the least copying is 17772 chosen. If two alternatives need the same amount of copying, the one 17773 that comes first is chosen. These choices can be altered with the `?' 17774 and `!' characters: 17775 17776 `?' 17777 Disparage slightly the alternative that the `?' appears in, as a 17778 choice when no alternative applies exactly. The compiler regards 17779 this alternative as one unit more costly for each `?' that appears 17780 in it. 17781 17782 `!' 17783 Disparage severely the alternative that the `!' appears in. This 17784 alternative can still be used if it fits without reloading, but if 17785 reloading is needed, some other alternative will be used. 17786 17787 When an insn pattern has multiple alternatives in its constraints, 17788 often the appearance of the assembler code is determined mostly by which 17789 alternative was matched. When this is so, the C code for writing the 17790 assembler code can use the variable `which_alternative', which is the 17791 ordinal number of the alternative that was actually satisfied (0 for 17792 the first, 1 for the second alternative, etc.). *Note Output 17793 Statement::. 17794 17795 17796 File: gccint.info, Node: Class Preferences, Next: Modifiers, Prev: Multi-Alternative, Up: Constraints 17797 17798 16.8.3 Register Class Preferences 17799 --------------------------------- 17800 17801 The operand constraints have another function: they enable the compiler 17802 to decide which kind of hardware register a pseudo register is best 17803 allocated to. The compiler examines the constraints that apply to the 17804 insns that use the pseudo register, looking for the machine-dependent 17805 letters such as `d' and `a' that specify classes of registers. The 17806 pseudo register is put in whichever class gets the most "votes". The 17807 constraint letters `g' and `r' also vote: they vote in favor of a 17808 general register. The machine description says which registers are 17809 considered general. 17810 17811 Of course, on some machines all registers are equivalent, and no 17812 register classes are defined. Then none of this complexity is relevant. 17813 17814 17815 File: gccint.info, Node: Modifiers, Next: Disable Insn Alternatives, Prev: Class Preferences, Up: Constraints 17816 17817 16.8.4 Constraint Modifier Characters 17818 ------------------------------------- 17819 17820 Here are constraint modifier characters. 17821 17822 `=' 17823 Means that this operand is write-only for this instruction: the 17824 previous value is discarded and replaced by output data. 17825 17826 `+' 17827 Means that this operand is both read and written by the 17828 instruction. 17829 17830 When the compiler fixes up the operands to satisfy the constraints, 17831 it needs to know which operands are inputs to the instruction and 17832 which are outputs from it. `=' identifies an output; `+' 17833 identifies an operand that is both input and output; all other 17834 operands are assumed to be input only. 17835 17836 If you specify `=' or `+' in a constraint, you put it in the first 17837 character of the constraint string. 17838 17839 `&' 17840 Means (in a particular alternative) that this operand is an 17841 "earlyclobber" operand, which is modified before the instruction is 17842 finished using the input operands. Therefore, this operand may 17843 not lie in a register that is used as an input operand or as part 17844 of any memory address. 17845 17846 `&' applies only to the alternative in which it is written. In 17847 constraints with multiple alternatives, sometimes one alternative 17848 requires `&' while others do not. See, for example, the `movdf' 17849 insn of the 68000. 17850 17851 An input operand can be tied to an earlyclobber operand if its only 17852 use as an input occurs before the early result is written. Adding 17853 alternatives of this form often allows GCC to produce better code 17854 when only some of the inputs can be affected by the earlyclobber. 17855 See, for example, the `mulsi3' insn of the ARM. 17856 17857 `&' does not obviate the need to write `='. 17858 17859 `%' 17860 Declares the instruction to be commutative for this operand and the 17861 following operand. This means that the compiler may interchange 17862 the two operands if that is the cheapest way to make all operands 17863 fit the constraints. This is often used in patterns for addition 17864 instructions that really have only two operands: the result must 17865 go in one of the arguments. Here for example, is how the 68000 17866 halfword-add instruction is defined: 17867 17868 (define_insn "addhi3" 17869 [(set (match_operand:HI 0 "general_operand" "=m,r") 17870 (plus:HI (match_operand:HI 1 "general_operand" "%0,0") 17871 (match_operand:HI 2 "general_operand" "di,g")))] 17872 ...) 17873 GCC can only handle one commutative pair in an asm; if you use 17874 more, the compiler may fail. Note that you need not use the 17875 modifier if the two alternatives are strictly identical; this 17876 would only waste time in the reload pass. The modifier is not 17877 operational after register allocation, so the result of 17878 `define_peephole2' and `define_split's performed after reload 17879 cannot rely on `%' to make the intended insn match. 17880 17881 `#' 17882 Says that all following characters, up to the next comma, are to be 17883 ignored as a constraint. They are significant only for choosing 17884 register preferences. 17885 17886 `*' 17887 Says that the following character should be ignored when choosing 17888 register preferences. `*' has no effect on the meaning of the 17889 constraint as a constraint, and no effect on reloading. 17890 17891 Here is an example: the 68000 has an instruction to sign-extend a 17892 halfword in a data register, and can also sign-extend a value by 17893 copying it into an address register. While either kind of 17894 register is acceptable, the constraints on an address-register 17895 destination are less strict, so it is best if register allocation 17896 makes an address register its goal. Therefore, `*' is used so 17897 that the `d' constraint letter (for data register) is ignored when 17898 computing register preferences. 17899 17900 (define_insn "extendhisi2" 17901 [(set (match_operand:SI 0 "general_operand" "=*d,a") 17902 (sign_extend:SI 17903 (match_operand:HI 1 "general_operand" "0,g")))] 17904 ...) 17905 17906 17907 File: gccint.info, Node: Machine Constraints, Next: Define Constraints, Prev: Disable Insn Alternatives, Up: Constraints 17908 17909 16.8.5 Constraints for Particular Machines 17910 ------------------------------------------ 17911 17912 Whenever possible, you should use the general-purpose constraint letters 17913 in `asm' arguments, since they will convey meaning more readily to 17914 people reading your code. Failing that, use the constraint letters 17915 that usually have very similar meanings across architectures. The most 17916 commonly used constraints are `m' and `r' (for memory and 17917 general-purpose registers respectively; *note Simple Constraints::), and 17918 `I', usually the letter indicating the most common immediate-constant 17919 format. 17920 17921 Each architecture defines additional constraints. These constraints 17922 are used by the compiler itself for instruction generation, as well as 17923 for `asm' statements; therefore, some of the constraints are not 17924 particularly useful for `asm'. Here is a summary of some of the 17925 machine-dependent constraints available on some particular machines; it 17926 includes both constraints that are useful for `asm' and constraints 17927 that aren't. The compiler source file mentioned in the table heading 17928 for each architecture is the definitive reference for the meanings of 17929 that architecture's constraints. 17930 17931 _ARM family--`config/arm/arm.h'_ 17932 17933 `f' 17934 Floating-point register 17935 17936 `w' 17937 VFP floating-point register 17938 17939 `F' 17940 One of the floating-point constants 0.0, 0.5, 1.0, 2.0, 3.0, 17941 4.0, 5.0 or 10.0 17942 17943 `G' 17944 Floating-point constant that would satisfy the constraint `F' 17945 if it were negated 17946 17947 `I' 17948 Integer that is valid as an immediate operand in a data 17949 processing instruction. That is, an integer in the range 0 17950 to 255 rotated by a multiple of 2 17951 17952 `J' 17953 Integer in the range -4095 to 4095 17954 17955 `K' 17956 Integer that satisfies constraint `I' when inverted (ones 17957 complement) 17958 17959 `L' 17960 Integer that satisfies constraint `I' when negated (twos 17961 complement) 17962 17963 `M' 17964 Integer in the range 0 to 32 17965 17966 `Q' 17967 A memory reference where the exact address is in a single 17968 register (``m'' is preferable for `asm' statements) 17969 17970 `R' 17971 An item in the constant pool 17972 17973 `S' 17974 A symbol in the text segment of the current file 17975 17976 `Uv' 17977 A memory reference suitable for VFP load/store insns 17978 (reg+constant offset) 17979 17980 `Uy' 17981 A memory reference suitable for iWMMXt load/store 17982 instructions. 17983 17984 `Uq' 17985 A memory reference suitable for the ARMv4 ldrsb instruction. 17986 17987 _AVR family--`config/avr/constraints.md'_ 17988 17989 `l' 17990 Registers from r0 to r15 17991 17992 `a' 17993 Registers from r16 to r23 17994 17995 `d' 17996 Registers from r16 to r31 17997 17998 `w' 17999 Registers from r24 to r31. These registers can be used in 18000 `adiw' command 18001 18002 `e' 18003 Pointer register (r26-r31) 18004 18005 `b' 18006 Base pointer register (r28-r31) 18007 18008 `q' 18009 Stack pointer register (SPH:SPL) 18010 18011 `t' 18012 Temporary register r0 18013 18014 `x' 18015 Register pair X (r27:r26) 18016 18017 `y' 18018 Register pair Y (r29:r28) 18019 18020 `z' 18021 Register pair Z (r31:r30) 18022 18023 `I' 18024 Constant greater than -1, less than 64 18025 18026 `J' 18027 Constant greater than -64, less than 1 18028 18029 `K' 18030 Constant integer 2 18031 18032 `L' 18033 Constant integer 0 18034 18035 `M' 18036 Constant that fits in 8 bits 18037 18038 `N' 18039 Constant integer -1 18040 18041 `O' 18042 Constant integer 8, 16, or 24 18043 18044 `P' 18045 Constant integer 1 18046 18047 `G' 18048 A floating point constant 0.0 18049 18050 `R' 18051 Integer constant in the range -6 ... 5. 18052 18053 `Q' 18054 A memory address based on Y or Z pointer with displacement. 18055 18056 _CRX Architecture--`config/crx/crx.h'_ 18057 18058 `b' 18059 Registers from r0 to r14 (registers without stack pointer) 18060 18061 `l' 18062 Register r16 (64-bit accumulator lo register) 18063 18064 `h' 18065 Register r17 (64-bit accumulator hi register) 18066 18067 `k' 18068 Register pair r16-r17. (64-bit accumulator lo-hi pair) 18069 18070 `I' 18071 Constant that fits in 3 bits 18072 18073 `J' 18074 Constant that fits in 4 bits 18075 18076 `K' 18077 Constant that fits in 5 bits 18078 18079 `L' 18080 Constant that is one of -1, 4, -4, 7, 8, 12, 16, 20, 32, 48 18081 18082 `G' 18083 Floating point constant that is legal for store immediate 18084 18085 _Hewlett-Packard PA-RISC--`config/pa/pa.h'_ 18086 18087 `a' 18088 General register 1 18089 18090 `f' 18091 Floating point register 18092 18093 `q' 18094 Shift amount register 18095 18096 `x' 18097 Floating point register (deprecated) 18098 18099 `y' 18100 Upper floating point register (32-bit), floating point 18101 register (64-bit) 18102 18103 `Z' 18104 Any register 18105 18106 `I' 18107 Signed 11-bit integer constant 18108 18109 `J' 18110 Signed 14-bit integer constant 18111 18112 `K' 18113 Integer constant that can be deposited with a `zdepi' 18114 instruction 18115 18116 `L' 18117 Signed 5-bit integer constant 18118 18119 `M' 18120 Integer constant 0 18121 18122 `N' 18123 Integer constant that can be loaded with a `ldil' instruction 18124 18125 `O' 18126 Integer constant whose value plus one is a power of 2 18127 18128 `P' 18129 Integer constant that can be used for `and' operations in 18130 `depi' and `extru' instructions 18131 18132 `S' 18133 Integer constant 31 18134 18135 `U' 18136 Integer constant 63 18137 18138 `G' 18139 Floating-point constant 0.0 18140 18141 `A' 18142 A `lo_sum' data-linkage-table memory operand 18143 18144 `Q' 18145 A memory operand that can be used as the destination operand 18146 of an integer store instruction 18147 18148 `R' 18149 A scaled or unscaled indexed memory operand 18150 18151 `T' 18152 A memory operand for floating-point loads and stores 18153 18154 `W' 18155 A register indirect memory operand 18156 18157 _picoChip family--`picochip.h'_ 18158 18159 `k' 18160 Stack register. 18161 18162 `f' 18163 Pointer register. A register which can be used to access 18164 memory without supplying an offset. Any other register can 18165 be used to access memory, but will need a constant offset. 18166 In the case of the offset being zero, it is more efficient to 18167 use a pointer register, since this reduces code size. 18168 18169 `t' 18170 A twin register. A register which may be paired with an 18171 adjacent register to create a 32-bit register. 18172 18173 `a' 18174 Any absolute memory address (e.g., symbolic constant, symbolic 18175 constant + offset). 18176 18177 `I' 18178 4-bit signed integer. 18179 18180 `J' 18181 4-bit unsigned integer. 18182 18183 `K' 18184 8-bit signed integer. 18185 18186 `M' 18187 Any constant whose absolute value is no greater than 4-bits. 18188 18189 `N' 18190 10-bit signed integer 18191 18192 `O' 18193 16-bit signed integer. 18194 18195 18196 _PowerPC and IBM RS6000--`config/rs6000/rs6000.h'_ 18197 18198 `b' 18199 Address base register 18200 18201 `f' 18202 Floating point register 18203 18204 `v' 18205 Vector register 18206 18207 `h' 18208 `MQ', `CTR', or `LINK' register 18209 18210 `q' 18211 `MQ' register 18212 18213 `c' 18214 `CTR' register 18215 18216 `l' 18217 `LINK' register 18218 18219 `x' 18220 `CR' register (condition register) number 0 18221 18222 `y' 18223 `CR' register (condition register) 18224 18225 `z' 18226 `FPMEM' stack memory for FPR-GPR transfers 18227 18228 `I' 18229 Signed 16-bit constant 18230 18231 `J' 18232 Unsigned 16-bit constant shifted left 16 bits (use `L' 18233 instead for `SImode' constants) 18234 18235 `K' 18236 Unsigned 16-bit constant 18237 18238 `L' 18239 Signed 16-bit constant shifted left 16 bits 18240 18241 `M' 18242 Constant larger than 31 18243 18244 `N' 18245 Exact power of 2 18246 18247 `O' 18248 Zero 18249 18250 `P' 18251 Constant whose negation is a signed 16-bit constant 18252 18253 `G' 18254 Floating point constant that can be loaded into a register 18255 with one instruction per word 18256 18257 `H' 18258 Integer/Floating point constant that can be loaded into a 18259 register using three instructions 18260 18261 `Q' 18262 Memory operand that is an offset from a register (`m' is 18263 preferable for `asm' statements) 18264 18265 `Z' 18266 Memory operand that is an indexed or indirect from a register 18267 (`m' is preferable for `asm' statements) 18268 18269 `R' 18270 AIX TOC entry 18271 18272 `a' 18273 Address operand that is an indexed or indirect from a 18274 register (`p' is preferable for `asm' statements) 18275 18276 `S' 18277 Constant suitable as a 64-bit mask operand 18278 18279 `T' 18280 Constant suitable as a 32-bit mask operand 18281 18282 `U' 18283 System V Release 4 small data area reference 18284 18285 `t' 18286 AND masks that can be performed by two rldic{l, r} 18287 instructions 18288 18289 `W' 18290 Vector constant that does not require memory 18291 18292 18293 _Intel 386--`config/i386/constraints.md'_ 18294 18295 `R' 18296 Legacy register--the eight integer registers available on all 18297 i386 processors (`a', `b', `c', `d', `si', `di', `bp', `sp'). 18298 18299 `q' 18300 Any register accessible as `Rl'. In 32-bit mode, `a', `b', 18301 `c', and `d'; in 64-bit mode, any integer register. 18302 18303 `Q' 18304 Any register accessible as `Rh': `a', `b', `c', and `d'. 18305 18306 `l' 18307 Any register that can be used as the index in a base+index 18308 memory access: that is, any general register except the stack 18309 pointer. 18310 18311 `a' 18312 The `a' register. 18313 18314 `b' 18315 The `b' register. 18316 18317 `c' 18318 The `c' register. 18319 18320 `d' 18321 The `d' register. 18322 18323 `S' 18324 The `si' register. 18325 18326 `D' 18327 The `di' register. 18328 18329 `A' 18330 The `a' and `d' registers, as a pair (for instructions that 18331 return half the result in one and half in the other). 18332 18333 `f' 18334 Any 80387 floating-point (stack) register. 18335 18336 `t' 18337 Top of 80387 floating-point stack (`%st(0)'). 18338 18339 `u' 18340 Second from top of 80387 floating-point stack (`%st(1)'). 18341 18342 `y' 18343 Any MMX register. 18344 18345 `x' 18346 Any SSE register. 18347 18348 `Yz' 18349 First SSE register (`%xmm0'). 18350 18351 `Y2' 18352 Any SSE register, when SSE2 is enabled. 18353 18354 `Yi' 18355 Any SSE register, when SSE2 and inter-unit moves are enabled. 18356 18357 `Ym' 18358 Any MMX register, when inter-unit moves are enabled. 18359 18360 `I' 18361 Integer constant in the range 0 ... 31, for 32-bit shifts. 18362 18363 `J' 18364 Integer constant in the range 0 ... 63, for 64-bit shifts. 18365 18366 `K' 18367 Signed 8-bit integer constant. 18368 18369 `L' 18370 `0xFF' or `0xFFFF', for andsi as a zero-extending move. 18371 18372 `M' 18373 0, 1, 2, or 3 (shifts for the `lea' instruction). 18374 18375 `N' 18376 Unsigned 8-bit integer constant (for `in' and `out' 18377 instructions). 18378 18379 `O' 18380 Integer constant in the range 0 ... 127, for 128-bit shifts. 18381 18382 `G' 18383 Standard 80387 floating point constant. 18384 18385 `C' 18386 Standard SSE floating point constant. 18387 18388 `e' 18389 32-bit signed integer constant, or a symbolic reference known 18390 to fit that range (for immediate operands in sign-extending 18391 x86-64 instructions). 18392 18393 `Z' 18394 32-bit unsigned integer constant, or a symbolic reference 18395 known to fit that range (for immediate operands in 18396 zero-extending x86-64 instructions). 18397 18398 18399 _Intel IA-64--`config/ia64/ia64.h'_ 18400 18401 `a' 18402 General register `r0' to `r3' for `addl' instruction 18403 18404 `b' 18405 Branch register 18406 18407 `c' 18408 Predicate register (`c' as in "conditional") 18409 18410 `d' 18411 Application register residing in M-unit 18412 18413 `e' 18414 Application register residing in I-unit 18415 18416 `f' 18417 Floating-point register 18418 18419 `m' 18420 Memory operand. Remember that `m' allows postincrement and 18421 postdecrement which require printing with `%Pn' on IA-64. 18422 Use `S' to disallow postincrement and postdecrement. 18423 18424 `G' 18425 Floating-point constant 0.0 or 1.0 18426 18427 `I' 18428 14-bit signed integer constant 18429 18430 `J' 18431 22-bit signed integer constant 18432 18433 `K' 18434 8-bit signed integer constant for logical instructions 18435 18436 `L' 18437 8-bit adjusted signed integer constant for compare pseudo-ops 18438 18439 `M' 18440 6-bit unsigned integer constant for shift counts 18441 18442 `N' 18443 9-bit signed integer constant for load and store 18444 postincrements 18445 18446 `O' 18447 The constant zero 18448 18449 `P' 18450 0 or -1 for `dep' instruction 18451 18452 `Q' 18453 Non-volatile memory for floating-point loads and stores 18454 18455 `R' 18456 Integer constant in the range 1 to 4 for `shladd' instruction 18457 18458 `S' 18459 Memory operand except postincrement and postdecrement 18460 18461 _FRV--`config/frv/frv.h'_ 18462 18463 `a' 18464 Register in the class `ACC_REGS' (`acc0' to `acc7'). 18465 18466 `b' 18467 Register in the class `EVEN_ACC_REGS' (`acc0' to `acc7'). 18468 18469 `c' 18470 Register in the class `CC_REGS' (`fcc0' to `fcc3' and `icc0' 18471 to `icc3'). 18472 18473 `d' 18474 Register in the class `GPR_REGS' (`gr0' to `gr63'). 18475 18476 `e' 18477 Register in the class `EVEN_REGS' (`gr0' to `gr63'). Odd 18478 registers are excluded not in the class but through the use 18479 of a machine mode larger than 4 bytes. 18480 18481 `f' 18482 Register in the class `FPR_REGS' (`fr0' to `fr63'). 18483 18484 `h' 18485 Register in the class `FEVEN_REGS' (`fr0' to `fr63'). Odd 18486 registers are excluded not in the class but through the use 18487 of a machine mode larger than 4 bytes. 18488 18489 `l' 18490 Register in the class `LR_REG' (the `lr' register). 18491 18492 `q' 18493 Register in the class `QUAD_REGS' (`gr2' to `gr63'). 18494 Register numbers not divisible by 4 are excluded not in the 18495 class but through the use of a machine mode larger than 8 18496 bytes. 18497 18498 `t' 18499 Register in the class `ICC_REGS' (`icc0' to `icc3'). 18500 18501 `u' 18502 Register in the class `FCC_REGS' (`fcc0' to `fcc3'). 18503 18504 `v' 18505 Register in the class `ICR_REGS' (`cc4' to `cc7'). 18506 18507 `w' 18508 Register in the class `FCR_REGS' (`cc0' to `cc3'). 18509 18510 `x' 18511 Register in the class `QUAD_FPR_REGS' (`fr0' to `fr63'). 18512 Register numbers not divisible by 4 are excluded not in the 18513 class but through the use of a machine mode larger than 8 18514 bytes. 18515 18516 `z' 18517 Register in the class `SPR_REGS' (`lcr' and `lr'). 18518 18519 `A' 18520 Register in the class `QUAD_ACC_REGS' (`acc0' to `acc7'). 18521 18522 `B' 18523 Register in the class `ACCG_REGS' (`accg0' to `accg7'). 18524 18525 `C' 18526 Register in the class `CR_REGS' (`cc0' to `cc7'). 18527 18528 `G' 18529 Floating point constant zero 18530 18531 `I' 18532 6-bit signed integer constant 18533 18534 `J' 18535 10-bit signed integer constant 18536 18537 `L' 18538 16-bit signed integer constant 18539 18540 `M' 18541 16-bit unsigned integer constant 18542 18543 `N' 18544 12-bit signed integer constant that is negative--i.e. in the 18545 range of -2048 to -1 18546 18547 `O' 18548 Constant zero 18549 18550 `P' 18551 12-bit signed integer constant that is greater than 18552 zero--i.e. in the range of 1 to 2047. 18553 18554 18555 _Blackfin family--`config/bfin/constraints.md'_ 18556 18557 `a' 18558 P register 18559 18560 `d' 18561 D register 18562 18563 `z' 18564 A call clobbered P register. 18565 18566 `qN' 18567 A single register. If N is in the range 0 to 7, the 18568 corresponding D register. If it is `A', then the register P0. 18569 18570 `D' 18571 Even-numbered D register 18572 18573 `W' 18574 Odd-numbered D register 18575 18576 `e' 18577 Accumulator register. 18578 18579 `A' 18580 Even-numbered accumulator register. 18581 18582 `B' 18583 Odd-numbered accumulator register. 18584 18585 `b' 18586 I register 18587 18588 `v' 18589 B register 18590 18591 `f' 18592 M register 18593 18594 `c' 18595 Registers used for circular buffering, i.e. I, B, or L 18596 registers. 18597 18598 `C' 18599 The CC register. 18600 18601 `t' 18602 LT0 or LT1. 18603 18604 `k' 18605 LC0 or LC1. 18606 18607 `u' 18608 LB0 or LB1. 18609 18610 `x' 18611 Any D, P, B, M, I or L register. 18612 18613 `y' 18614 Additional registers typically used only in prologues and 18615 epilogues: RETS, RETN, RETI, RETX, RETE, ASTAT, SEQSTAT and 18616 USP. 18617 18618 `w' 18619 Any register except accumulators or CC. 18620 18621 `Ksh' 18622 Signed 16 bit integer (in the range -32768 to 32767) 18623 18624 `Kuh' 18625 Unsigned 16 bit integer (in the range 0 to 65535) 18626 18627 `Ks7' 18628 Signed 7 bit integer (in the range -64 to 63) 18629 18630 `Ku7' 18631 Unsigned 7 bit integer (in the range 0 to 127) 18632 18633 `Ku5' 18634 Unsigned 5 bit integer (in the range 0 to 31) 18635 18636 `Ks4' 18637 Signed 4 bit integer (in the range -8 to 7) 18638 18639 `Ks3' 18640 Signed 3 bit integer (in the range -3 to 4) 18641 18642 `Ku3' 18643 Unsigned 3 bit integer (in the range 0 to 7) 18644 18645 `PN' 18646 Constant N, where N is a single-digit constant in the range 0 18647 to 4. 18648 18649 `PA' 18650 An integer equal to one of the MACFLAG_XXX constants that is 18651 suitable for use with either accumulator. 18652 18653 `PB' 18654 An integer equal to one of the MACFLAG_XXX constants that is 18655 suitable for use only with accumulator A1. 18656 18657 `M1' 18658 Constant 255. 18659 18660 `M2' 18661 Constant 65535. 18662 18663 `J' 18664 An integer constant with exactly a single bit set. 18665 18666 `L' 18667 An integer constant with all bits set except exactly one. 18668 18669 `H' 18670 18671 `Q' 18672 Any SYMBOL_REF. 18673 18674 _M32C--`config/m32c/m32c.c'_ 18675 18676 `Rsp' 18677 `Rfb' 18678 `Rsb' 18679 `$sp', `$fb', `$sb'. 18680 18681 `Rcr' 18682 Any control register, when they're 16 bits wide (nothing if 18683 control registers are 24 bits wide) 18684 18685 `Rcl' 18686 Any control register, when they're 24 bits wide. 18687 18688 `R0w' 18689 `R1w' 18690 `R2w' 18691 `R3w' 18692 $r0, $r1, $r2, $r3. 18693 18694 `R02' 18695 $r0 or $r2, or $r2r0 for 32 bit values. 18696 18697 `R13' 18698 $r1 or $r3, or $r3r1 for 32 bit values. 18699 18700 `Rdi' 18701 A register that can hold a 64 bit value. 18702 18703 `Rhl' 18704 $r0 or $r1 (registers with addressable high/low bytes) 18705 18706 `R23' 18707 $r2 or $r3 18708 18709 `Raa' 18710 Address registers 18711 18712 `Raw' 18713 Address registers when they're 16 bits wide. 18714 18715 `Ral' 18716 Address registers when they're 24 bits wide. 18717 18718 `Rqi' 18719 Registers that can hold QI values. 18720 18721 `Rad' 18722 Registers that can be used with displacements ($a0, $a1, $sb). 18723 18724 `Rsi' 18725 Registers that can hold 32 bit values. 18726 18727 `Rhi' 18728 Registers that can hold 16 bit values. 18729 18730 `Rhc' 18731 Registers chat can hold 16 bit values, including all control 18732 registers. 18733 18734 `Rra' 18735 $r0 through R1, plus $a0 and $a1. 18736 18737 `Rfl' 18738 The flags register. 18739 18740 `Rmm' 18741 The memory-based pseudo-registers $mem0 through $mem15. 18742 18743 `Rpi' 18744 Registers that can hold pointers (16 bit registers for r8c, 18745 m16c; 24 bit registers for m32cm, m32c). 18746 18747 `Rpa' 18748 Matches multiple registers in a PARALLEL to form a larger 18749 register. Used to match function return values. 18750 18751 `Is3' 18752 -8 ... 7 18753 18754 `IS1' 18755 -128 ... 127 18756 18757 `IS2' 18758 -32768 ... 32767 18759 18760 `IU2' 18761 0 ... 65535 18762 18763 `In4' 18764 -8 ... -1 or 1 ... 8 18765 18766 `In5' 18767 -16 ... -1 or 1 ... 16 18768 18769 `In6' 18770 -32 ... -1 or 1 ... 32 18771 18772 `IM2' 18773 -65536 ... -1 18774 18775 `Ilb' 18776 An 8 bit value with exactly one bit set. 18777 18778 `Ilw' 18779 A 16 bit value with exactly one bit set. 18780 18781 `Sd' 18782 The common src/dest memory addressing modes. 18783 18784 `Sa' 18785 Memory addressed using $a0 or $a1. 18786 18787 `Si' 18788 Memory addressed with immediate addresses. 18789 18790 `Ss' 18791 Memory addressed using the stack pointer ($sp). 18792 18793 `Sf' 18794 Memory addressed using the frame base register ($fb). 18795 18796 `Ss' 18797 Memory addressed using the small base register ($sb). 18798 18799 `S1' 18800 $r1h 18801 18802 _MIPS--`config/mips/constraints.md'_ 18803 18804 `d' 18805 An address register. This is equivalent to `r' unless 18806 generating MIPS16 code. 18807 18808 `f' 18809 A floating-point register (if available). 18810 18811 `h' 18812 Formerly the `hi' register. This constraint is no longer 18813 supported. 18814 18815 `l' 18816 The `lo' register. Use this register to store values that are 18817 no bigger than a word. 18818 18819 `x' 18820 The concatenated `hi' and `lo' registers. Use this register 18821 to store doubleword values. 18822 18823 `c' 18824 A register suitable for use in an indirect jump. This will 18825 always be `$25' for `-mabicalls'. 18826 18827 `v' 18828 Register `$3'. Do not use this constraint in new code; it is 18829 retained only for compatibility with glibc. 18830 18831 `y' 18832 Equivalent to `r'; retained for backwards compatibility. 18833 18834 `z' 18835 A floating-point condition code register. 18836 18837 `I' 18838 A signed 16-bit constant (for arithmetic instructions). 18839 18840 `J' 18841 Integer zero. 18842 18843 `K' 18844 An unsigned 16-bit constant (for logic instructions). 18845 18846 `L' 18847 A signed 32-bit constant in which the lower 16 bits are zero. 18848 Such constants can be loaded using `lui'. 18849 18850 `M' 18851 A constant that cannot be loaded using `lui', `addiu' or 18852 `ori'. 18853 18854 `N' 18855 A constant in the range -65535 to -1 (inclusive). 18856 18857 `O' 18858 A signed 15-bit constant. 18859 18860 `P' 18861 A constant in the range 1 to 65535 (inclusive). 18862 18863 `G' 18864 Floating-point zero. 18865 18866 `R' 18867 An address that can be used in a non-macro load or store. 18868 18869 _Motorola 680x0--`config/m68k/constraints.md'_ 18870 18871 `a' 18872 Address register 18873 18874 `d' 18875 Data register 18876 18877 `f' 18878 68881 floating-point register, if available 18879 18880 `I' 18881 Integer in the range 1 to 8 18882 18883 `J' 18884 16-bit signed number 18885 18886 `K' 18887 Signed number whose magnitude is greater than 0x80 18888 18889 `L' 18890 Integer in the range -8 to -1 18891 18892 `M' 18893 Signed number whose magnitude is greater than 0x100 18894 18895 `N' 18896 Range 24 to 31, rotatert:SI 8 to 1 expressed as rotate 18897 18898 `O' 18899 16 (for rotate using swap) 18900 18901 `P' 18902 Range 8 to 15, rotatert:HI 8 to 1 expressed as rotate 18903 18904 `R' 18905 Numbers that mov3q can handle 18906 18907 `G' 18908 Floating point constant that is not a 68881 constant 18909 18910 `S' 18911 Operands that satisfy 'm' when -mpcrel is in effect 18912 18913 `T' 18914 Operands that satisfy 's' when -mpcrel is not in effect 18915 18916 `Q' 18917 Address register indirect addressing mode 18918 18919 `U' 18920 Register offset addressing 18921 18922 `W' 18923 const_call_operand 18924 18925 `Cs' 18926 symbol_ref or const 18927 18928 `Ci' 18929 const_int 18930 18931 `C0' 18932 const_int 0 18933 18934 `Cj' 18935 Range of signed numbers that don't fit in 16 bits 18936 18937 `Cmvq' 18938 Integers valid for mvq 18939 18940 `Capsw' 18941 Integers valid for a moveq followed by a swap 18942 18943 `Cmvz' 18944 Integers valid for mvz 18945 18946 `Cmvs' 18947 Integers valid for mvs 18948 18949 `Ap' 18950 push_operand 18951 18952 `Ac' 18953 Non-register operands allowed in clr 18954 18955 18956 _Motorola 68HC11 & 68HC12 families--`config/m68hc11/m68hc11.h'_ 18957 18958 `a' 18959 Register `a' 18960 18961 `b' 18962 Register `b' 18963 18964 `d' 18965 Register `d' 18966 18967 `q' 18968 An 8-bit register 18969 18970 `t' 18971 Temporary soft register _.tmp 18972 18973 `u' 18974 A soft register _.d1 to _.d31 18975 18976 `w' 18977 Stack pointer register 18978 18979 `x' 18980 Register `x' 18981 18982 `y' 18983 Register `y' 18984 18985 `z' 18986 Pseudo register `z' (replaced by `x' or `y' at the end) 18987 18988 `A' 18989 An address register: x, y or z 18990 18991 `B' 18992 An address register: x or y 18993 18994 `D' 18995 Register pair (x:d) to form a 32-bit value 18996 18997 `L' 18998 Constants in the range -65536 to 65535 18999 19000 `M' 19001 Constants whose 16-bit low part is zero 19002 19003 `N' 19004 Constant integer 1 or -1 19005 19006 `O' 19007 Constant integer 16 19008 19009 `P' 19010 Constants in the range -8 to 2 19011 19012 19013 _SPARC--`config/sparc/sparc.h'_ 19014 19015 `f' 19016 Floating-point register on the SPARC-V8 architecture and 19017 lower floating-point register on the SPARC-V9 architecture. 19018 19019 `e' 19020 Floating-point register. It is equivalent to `f' on the 19021 SPARC-V8 architecture and contains both lower and upper 19022 floating-point registers on the SPARC-V9 architecture. 19023 19024 `c' 19025 Floating-point condition code register. 19026 19027 `d' 19028 Lower floating-point register. It is only valid on the 19029 SPARC-V9 architecture when the Visual Instruction Set is 19030 available. 19031 19032 `b' 19033 Floating-point register. It is only valid on the SPARC-V9 19034 architecture when the Visual Instruction Set is available. 19035 19036 `h' 19037 64-bit global or out register for the SPARC-V8+ architecture. 19038 19039 `D' 19040 A vector constant 19041 19042 `I' 19043 Signed 13-bit constant 19044 19045 `J' 19046 Zero 19047 19048 `K' 19049 32-bit constant with the low 12 bits clear (a constant that 19050 can be loaded with the `sethi' instruction) 19051 19052 `L' 19053 A constant in the range supported by `movcc' instructions 19054 19055 `M' 19056 A constant in the range supported by `movrcc' instructions 19057 19058 `N' 19059 Same as `K', except that it verifies that bits that are not 19060 in the lower 32-bit range are all zero. Must be used instead 19061 of `K' for modes wider than `SImode' 19062 19063 `O' 19064 The constant 4096 19065 19066 `G' 19067 Floating-point zero 19068 19069 `H' 19070 Signed 13-bit constant, sign-extended to 32 or 64 bits 19071 19072 `Q' 19073 Floating-point constant whose integral representation can be 19074 moved into an integer register using a single sethi 19075 instruction 19076 19077 `R' 19078 Floating-point constant whose integral representation can be 19079 moved into an integer register using a single mov instruction 19080 19081 `S' 19082 Floating-point constant whose integral representation can be 19083 moved into an integer register using a high/lo_sum 19084 instruction sequence 19085 19086 `T' 19087 Memory address aligned to an 8-byte boundary 19088 19089 `U' 19090 Even register 19091 19092 `W' 19093 Memory address for `e' constraint registers 19094 19095 `Y' 19096 Vector zero 19097 19098 19099 _SPU--`config/spu/spu.h'_ 19100 19101 `a' 19102 An immediate which can be loaded with the il/ila/ilh/ilhu 19103 instructions. const_int is treated as a 64 bit value. 19104 19105 `c' 19106 An immediate for and/xor/or instructions. const_int is 19107 treated as a 64 bit value. 19108 19109 `d' 19110 An immediate for the `iohl' instruction. const_int is 19111 treated as a 64 bit value. 19112 19113 `f' 19114 An immediate which can be loaded with `fsmbi'. 19115 19116 `A' 19117 An immediate which can be loaded with the il/ila/ilh/ilhu 19118 instructions. const_int is treated as a 32 bit value. 19119 19120 `B' 19121 An immediate for most arithmetic instructions. const_int is 19122 treated as a 32 bit value. 19123 19124 `C' 19125 An immediate for and/xor/or instructions. const_int is 19126 treated as a 32 bit value. 19127 19128 `D' 19129 An immediate for the `iohl' instruction. const_int is 19130 treated as a 32 bit value. 19131 19132 `I' 19133 A constant in the range [-64, 63] for shift/rotate 19134 instructions. 19135 19136 `J' 19137 An unsigned 7-bit constant for conversion/nop/channel 19138 instructions. 19139 19140 `K' 19141 A signed 10-bit constant for most arithmetic instructions. 19142 19143 `M' 19144 A signed 16 bit immediate for `stop'. 19145 19146 `N' 19147 An unsigned 16-bit constant for `iohl' and `fsmbi'. 19148 19149 `O' 19150 An unsigned 7-bit constant whose 3 least significant bits are 19151 0. 19152 19153 `P' 19154 An unsigned 3-bit constant for 16-byte rotates and shifts 19155 19156 `R' 19157 Call operand, reg, for indirect calls 19158 19159 `S' 19160 Call operand, symbol, for relative calls. 19161 19162 `T' 19163 Call operand, const_int, for absolute calls. 19164 19165 `U' 19166 An immediate which can be loaded with the il/ila/ilh/ilhu 19167 instructions. const_int is sign extended to 128 bit. 19168 19169 `W' 19170 An immediate for shift and rotate instructions. const_int is 19171 treated as a 32 bit value. 19172 19173 `Y' 19174 An immediate for and/xor/or instructions. const_int is sign 19175 extended as a 128 bit. 19176 19177 `Z' 19178 An immediate for the `iohl' instruction. const_int is sign 19179 extended to 128 bit. 19180 19181 19182 _S/390 and zSeries--`config/s390/s390.h'_ 19183 19184 `a' 19185 Address register (general purpose register except r0) 19186 19187 `c' 19188 Condition code register 19189 19190 `d' 19191 Data register (arbitrary general purpose register) 19192 19193 `f' 19194 Floating-point register 19195 19196 `I' 19197 Unsigned 8-bit constant (0-255) 19198 19199 `J' 19200 Unsigned 12-bit constant (0-4095) 19201 19202 `K' 19203 Signed 16-bit constant (-32768-32767) 19204 19205 `L' 19206 Value appropriate as displacement. 19207 `(0..4095)' 19208 for short displacement 19209 19210 `(-524288..524287)' 19211 for long displacement 19212 19213 `M' 19214 Constant integer with a value of 0x7fffffff. 19215 19216 `N' 19217 Multiple letter constraint followed by 4 parameter letters. 19218 `0..9:' 19219 number of the part counting from most to least 19220 significant 19221 19222 `H,Q:' 19223 mode of the part 19224 19225 `D,S,H:' 19226 mode of the containing operand 19227 19228 `0,F:' 19229 value of the other parts (F--all bits set) 19230 The constraint matches if the specified part of a constant 19231 has a value different from its other parts. 19232 19233 `Q' 19234 Memory reference without index register and with short 19235 displacement. 19236 19237 `R' 19238 Memory reference with index register and short displacement. 19239 19240 `S' 19241 Memory reference without index register but with long 19242 displacement. 19243 19244 `T' 19245 Memory reference with index register and long displacement. 19246 19247 `U' 19248 Pointer with short displacement. 19249 19250 `W' 19251 Pointer with long displacement. 19252 19253 `Y' 19254 Shift count operand. 19255 19256 19257 _Score family--`config/score/score.h'_ 19258 19259 `d' 19260 Registers from r0 to r32. 19261 19262 `e' 19263 Registers from r0 to r16. 19264 19265 `t' 19266 r8--r11 or r22--r27 registers. 19267 19268 `h' 19269 hi register. 19270 19271 `l' 19272 lo register. 19273 19274 `x' 19275 hi + lo register. 19276 19277 `q' 19278 cnt register. 19279 19280 `y' 19281 lcb register. 19282 19283 `z' 19284 scb register. 19285 19286 `a' 19287 cnt + lcb + scb register. 19288 19289 `c' 19290 cr0--cr15 register. 19291 19292 `b' 19293 cp1 registers. 19294 19295 `f' 19296 cp2 registers. 19297 19298 `i' 19299 cp3 registers. 19300 19301 `j' 19302 cp1 + cp2 + cp3 registers. 19303 19304 `I' 19305 High 16-bit constant (32-bit constant with 16 LSBs zero). 19306 19307 `J' 19308 Unsigned 5 bit integer (in the range 0 to 31). 19309 19310 `K' 19311 Unsigned 16 bit integer (in the range 0 to 65535). 19312 19313 `L' 19314 Signed 16 bit integer (in the range -32768 to 32767). 19315 19316 `M' 19317 Unsigned 14 bit integer (in the range 0 to 16383). 19318 19319 `N' 19320 Signed 14 bit integer (in the range -8192 to 8191). 19321 19322 `Z' 19323 Any SYMBOL_REF. 19324 19325 _Xstormy16--`config/stormy16/stormy16.h'_ 19326 19327 `a' 19328 Register r0. 19329 19330 `b' 19331 Register r1. 19332 19333 `c' 19334 Register r2. 19335 19336 `d' 19337 Register r8. 19338 19339 `e' 19340 Registers r0 through r7. 19341 19342 `t' 19343 Registers r0 and r1. 19344 19345 `y' 19346 The carry register. 19347 19348 `z' 19349 Registers r8 and r9. 19350 19351 `I' 19352 A constant between 0 and 3 inclusive. 19353 19354 `J' 19355 A constant that has exactly one bit set. 19356 19357 `K' 19358 A constant that has exactly one bit clear. 19359 19360 `L' 19361 A constant between 0 and 255 inclusive. 19362 19363 `M' 19364 A constant between -255 and 0 inclusive. 19365 19366 `N' 19367 A constant between -3 and 0 inclusive. 19368 19369 `O' 19370 A constant between 1 and 4 inclusive. 19371 19372 `P' 19373 A constant between -4 and -1 inclusive. 19374 19375 `Q' 19376 A memory reference that is a stack push. 19377 19378 `R' 19379 A memory reference that is a stack pop. 19380 19381 `S' 19382 A memory reference that refers to a constant address of known 19383 value. 19384 19385 `T' 19386 The register indicated by Rx (not implemented yet). 19387 19388 `U' 19389 A constant that is not between 2 and 15 inclusive. 19390 19391 `Z' 19392 The constant 0. 19393 19394 19395 _Xtensa--`config/xtensa/constraints.md'_ 19396 19397 `a' 19398 General-purpose 32-bit register 19399 19400 `b' 19401 One-bit boolean register 19402 19403 `A' 19404 MAC16 40-bit accumulator register 19405 19406 `I' 19407 Signed 12-bit integer constant, for use in MOVI instructions 19408 19409 `J' 19410 Signed 8-bit integer constant, for use in ADDI instructions 19411 19412 `K' 19413 Integer constant valid for BccI instructions 19414 19415 `L' 19416 Unsigned constant valid for BccUI instructions 19417 19418 19419 19420 19421 File: gccint.info, Node: Disable Insn Alternatives, Next: Machine Constraints, Prev: Modifiers, Up: Constraints 19422 19423 16.8.6 Disable insn alternatives using the `enabled' attribute 19424 -------------------------------------------------------------- 19425 19426 The `enabled' insn attribute may be used to disable certain insn 19427 alternatives for machine-specific reasons. This is useful when adding 19428 new instructions to an existing pattern which are only available for 19429 certain cpu architecture levels as specified with the `-march=' option. 19430 19431 If an insn alternative is disabled, then it will never be used. The 19432 compiler treats the constraints for the disabled alternative as 19433 unsatisfiable. 19434 19435 In order to make use of the `enabled' attribute a back end has to add 19436 in the machine description files: 19437 19438 1. A definition of the `enabled' insn attribute. The attribute is 19439 defined as usual using the `define_attr' command. This definition 19440 should be based on other insn attributes and/or target flags. The 19441 `enabled' attribute is a numeric attribute and should evaluate to 19442 `(const_int 1)' for an enabled alternative and to `(const_int 0)' 19443 otherwise. 19444 19445 2. A definition of another insn attribute used to describe for what 19446 reason an insn alternative might be available or not. E.g. 19447 `cpu_facility' as in the example below. 19448 19449 3. An assignment for the second attribute to each insn definition 19450 combining instructions which are not all available under the same 19451 circumstances. (Note: It obviously only makes sense for 19452 definitions with more than one alternative. Otherwise the insn 19453 pattern should be disabled or enabled using the insn condition.) 19454 19455 E.g. the following two patterns could easily be merged using the 19456 `enabled' attribute: 19457 19458 19459 (define_insn "*movdi_old" 19460 [(set (match_operand:DI 0 "register_operand" "=d") 19461 (match_operand:DI 1 "register_operand" " d"))] 19462 "!TARGET_NEW" 19463 "lgr %0,%1") 19464 19465 (define_insn "*movdi_new" 19466 [(set (match_operand:DI 0 "register_operand" "=d,f,d") 19467 (match_operand:DI 1 "register_operand" " d,d,f"))] 19468 "TARGET_NEW" 19469 "@ 19470 lgr %0,%1 19471 ldgr %0,%1 19472 lgdr %0,%1") 19473 19474 to: 19475 19476 19477 (define_insn "*movdi_combined" 19478 [(set (match_operand:DI 0 "register_operand" "=d,f,d") 19479 (match_operand:DI 1 "register_operand" " d,d,f"))] 19480 "" 19481 "@ 19482 lgr %0,%1 19483 ldgr %0,%1 19484 lgdr %0,%1" 19485 [(set_attr "cpu_facility" "*,new,new")]) 19486 19487 with the `enabled' attribute defined like this: 19488 19489 19490 (define_attr "cpu_facility" "standard,new" (const_string "standard")) 19491 19492 (define_attr "enabled" "" 19493 (cond [(eq_attr "cpu_facility" "standard") (const_int 1) 19494 (and (eq_attr "cpu_facility" "new") 19495 (ne (symbol_ref "TARGET_NEW") (const_int 0))) 19496 (const_int 1)] 19497 (const_int 0))) 19498 19499 19500 File: gccint.info, Node: Define Constraints, Next: C Constraint Interface, Prev: Machine Constraints, Up: Constraints 19501 19502 16.8.7 Defining Machine-Specific Constraints 19503 -------------------------------------------- 19504 19505 Machine-specific constraints fall into two categories: register and 19506 non-register constraints. Within the latter category, constraints 19507 which allow subsets of all possible memory or address operands should 19508 be specially marked, to give `reload' more information. 19509 19510 Machine-specific constraints can be given names of arbitrary length, 19511 but they must be entirely composed of letters, digits, underscores 19512 (`_'), and angle brackets (`< >'). Like C identifiers, they must begin 19513 with a letter or underscore. 19514 19515 In order to avoid ambiguity in operand constraint strings, no 19516 constraint can have a name that begins with any other constraint's 19517 name. For example, if `x' is defined as a constraint name, `xy' may 19518 not be, and vice versa. As a consequence of this rule, no constraint 19519 may begin with one of the generic constraint letters: `E F V X g i m n 19520 o p r s'. 19521 19522 Register constraints correspond directly to register classes. *Note 19523 Register Classes::. There is thus not much flexibility in their 19524 definitions. 19525 19526 -- MD Expression: define_register_constraint name regclass docstring 19527 All three arguments are string constants. NAME is the name of the 19528 constraint, as it will appear in `match_operand' expressions. If 19529 NAME is a multi-letter constraint its length shall be the same for 19530 all constraints starting with the same letter. REGCLASS can be 19531 either the name of the corresponding register class (*note 19532 Register Classes::), or a C expression which evaluates to the 19533 appropriate register class. If it is an expression, it must have 19534 no side effects, and it cannot look at the operand. The usual use 19535 of expressions is to map some register constraints to `NO_REGS' 19536 when the register class is not available on a given 19537 subarchitecture. 19538 19539 DOCSTRING is a sentence documenting the meaning of the constraint. 19540 Docstrings are explained further below. 19541 19542 Non-register constraints are more like predicates: the constraint 19543 definition gives a Boolean expression which indicates whether the 19544 constraint matches. 19545 19546 -- MD Expression: define_constraint name docstring exp 19547 The NAME and DOCSTRING arguments are the same as for 19548 `define_register_constraint', but note that the docstring comes 19549 immediately after the name for these expressions. EXP is an RTL 19550 expression, obeying the same rules as the RTL expressions in 19551 predicate definitions. *Note Defining Predicates::, for details. 19552 If it evaluates true, the constraint matches; if it evaluates 19553 false, it doesn't. Constraint expressions should indicate which 19554 RTL codes they might match, just like predicate expressions. 19555 19556 `match_test' C expressions have access to the following variables: 19557 19558 OP 19559 The RTL object defining the operand. 19560 19561 MODE 19562 The machine mode of OP. 19563 19564 IVAL 19565 `INTVAL (OP)', if OP is a `const_int'. 19566 19567 HVAL 19568 `CONST_DOUBLE_HIGH (OP)', if OP is an integer `const_double'. 19569 19570 LVAL 19571 `CONST_DOUBLE_LOW (OP)', if OP is an integer `const_double'. 19572 19573 RVAL 19574 `CONST_DOUBLE_REAL_VALUE (OP)', if OP is a floating-point 19575 `const_double'. 19576 19577 The *VAL variables should only be used once another piece of the 19578 expression has verified that OP is the appropriate kind of RTL 19579 object. 19580 19581 Most non-register constraints should be defined with 19582 `define_constraint'. The remaining two definition expressions are only 19583 appropriate for constraints that should be handled specially by 19584 `reload' if they fail to match. 19585 19586 -- MD Expression: define_memory_constraint name docstring exp 19587 Use this expression for constraints that match a subset of all 19588 memory operands: that is, `reload' can make them match by 19589 converting the operand to the form `(mem (reg X))', where X is a 19590 base register (from the register class specified by 19591 `BASE_REG_CLASS', *note Register Classes::). 19592 19593 For example, on the S/390, some instructions do not accept 19594 arbitrary memory references, but only those that do not make use 19595 of an index register. The constraint letter `Q' is defined to 19596 represent a memory address of this type. If `Q' is defined with 19597 `define_memory_constraint', a `Q' constraint can handle any memory 19598 operand, because `reload' knows it can simply copy the memory 19599 address into a base register if required. This is analogous to 19600 the way a `o' constraint can handle any memory operand. 19601 19602 The syntax and semantics are otherwise identical to 19603 `define_constraint'. 19604 19605 -- MD Expression: define_address_constraint name docstring exp 19606 Use this expression for constraints that match a subset of all 19607 address operands: that is, `reload' can make the constraint match 19608 by converting the operand to the form `(reg X)', again with X a 19609 base register. 19610 19611 Constraints defined with `define_address_constraint' can only be 19612 used with the `address_operand' predicate, or machine-specific 19613 predicates that work the same way. They are treated analogously to 19614 the generic `p' constraint. 19615 19616 The syntax and semantics are otherwise identical to 19617 `define_constraint'. 19618 19619 For historical reasons, names beginning with the letters `G H' are 19620 reserved for constraints that match only `const_double's, and names 19621 beginning with the letters `I J K L M N O P' are reserved for 19622 constraints that match only `const_int's. This may change in the 19623 future. For the time being, constraints with these names must be 19624 written in a stylized form, so that `genpreds' can tell you did it 19625 correctly: 19626 19627 (define_constraint "[GHIJKLMNOP]..." 19628 "DOC..." 19629 (and (match_code "const_int") ; `const_double' for G/H 19630 CONDITION...)) ; usually a `match_test' 19631 19632 It is fine to use names beginning with other letters for constraints 19633 that match `const_double's or `const_int's. 19634 19635 Each docstring in a constraint definition should be one or more 19636 complete sentences, marked up in Texinfo format. _They are currently 19637 unused._ In the future they will be copied into the GCC manual, in 19638 *Note Machine Constraints::, replacing the hand-maintained tables 19639 currently found in that section. Also, in the future the compiler may 19640 use this to give more helpful diagnostics when poor choice of `asm' 19641 constraints causes a reload failure. 19642 19643 If you put the pseudo-Texinfo directive `@internal' at the beginning 19644 of a docstring, then (in the future) it will appear only in the 19645 internals manual's version of the machine-specific constraint tables. 19646 Use this for constraints that should not appear in `asm' statements. 19647 19648 19649 File: gccint.info, Node: C Constraint Interface, Prev: Define Constraints, Up: Constraints 19650 19651 16.8.8 Testing constraints from C 19652 --------------------------------- 19653 19654 It is occasionally useful to test a constraint from C code rather than 19655 implicitly via the constraint string in a `match_operand'. The 19656 generated file `tm_p.h' declares a few interfaces for working with 19657 machine-specific constraints. None of these interfaces work with the 19658 generic constraints described in *Note Simple Constraints::. This may 19659 change in the future. 19660 19661 *Warning:* `tm_p.h' may declare other functions that operate on 19662 constraints, besides the ones documented here. Do not use those 19663 functions from machine-dependent code. They exist to implement the old 19664 constraint interface that machine-independent components of the 19665 compiler still expect. They will change or disappear in the future. 19666 19667 Some valid constraint names are not valid C identifiers, so there is a 19668 mangling scheme for referring to them from C. Constraint names that do 19669 not contain angle brackets or underscores are left unchanged. 19670 Underscores are doubled, each `<' is replaced with `_l', and each `>' 19671 with `_g'. Here are some examples: 19672 19673 *Original* *Mangled* 19674 `x' `x' 19675 `P42x' `P42x' 19676 `P4_x' `P4__x' 19677 `P4>x' `P4_gx' 19678 `P4>>' `P4_g_g' 19679 `P4_g>' `P4__g_g' 19680 19681 Throughout this section, the variable C is either a constraint in the 19682 abstract sense, or a constant from `enum constraint_num'; the variable 19683 M is a mangled constraint name (usually as part of a larger identifier). 19684 19685 -- Enum: constraint_num 19686 For each machine-specific constraint, there is a corresponding 19687 enumeration constant: `CONSTRAINT_' plus the mangled name of the 19688 constraint. Functions that take an `enum constraint_num' as an 19689 argument expect one of these constants. 19690 19691 Machine-independent constraints do not have associated constants. 19692 This may change in the future. 19693 19694 -- Function: inline bool satisfies_constraint_M (rtx EXP) 19695 For each machine-specific, non-register constraint M, there is one 19696 of these functions; it returns `true' if EXP satisfies the 19697 constraint. These functions are only visible if `rtl.h' was 19698 included before `tm_p.h'. 19699 19700 -- Function: bool constraint_satisfied_p (rtx EXP, enum constraint_num 19701 C) 19702 Like the `satisfies_constraint_M' functions, but the constraint to 19703 test is given as an argument, C. If C specifies a register 19704 constraint, this function will always return `false'. 19705 19706 -- Function: enum reg_class regclass_for_constraint (enum 19707 constraint_num C) 19708 Returns the register class associated with C. If C is not a 19709 register constraint, or those registers are not available for the 19710 currently selected subtarget, returns `NO_REGS'. 19711 19712 Here is an example use of `satisfies_constraint_M'. In peephole 19713 optimizations (*note Peephole Definitions::), operand constraint 19714 strings are ignored, so if there are relevant constraints, they must be 19715 tested in the C condition. In the example, the optimization is applied 19716 if operand 2 does _not_ satisfy the `K' constraint. (This is a 19717 simplified version of a peephole definition from the i386 machine 19718 description.) 19719 19720 (define_peephole2 19721 [(match_scratch:SI 3 "r") 19722 (set (match_operand:SI 0 "register_operand" "") 19723 (mult:SI (match_operand:SI 1 "memory_operand" "") 19724 (match_operand:SI 2 "immediate_operand" "")))] 19725 19726 "!satisfies_constraint_K (operands[2])" 19727 19728 [(set (match_dup 3) (match_dup 1)) 19729 (set (match_dup 0) (mult:SI (match_dup 3) (match_dup 2)))] 19730 19731 "") 19732 19733 19734 File: gccint.info, Node: Standard Names, Next: Pattern Ordering, Prev: Constraints, Up: Machine Desc 19735 19736 16.9 Standard Pattern Names For Generation 19737 ========================================== 19738 19739 Here is a table of the instruction names that are meaningful in the RTL 19740 generation pass of the compiler. Giving one of these names to an 19741 instruction pattern tells the RTL generation pass that it can use the 19742 pattern to accomplish a certain task. 19743 19744 `movM' 19745 Here M stands for a two-letter machine mode name, in lowercase. 19746 This instruction pattern moves data with that machine mode from 19747 operand 1 to operand 0. For example, `movsi' moves full-word data. 19748 19749 If operand 0 is a `subreg' with mode M of a register whose own 19750 mode is wider than M, the effect of this instruction is to store 19751 the specified value in the part of the register that corresponds 19752 to mode M. Bits outside of M, but which are within the same 19753 target word as the `subreg' are undefined. Bits which are outside 19754 the target word are left unchanged. 19755 19756 This class of patterns is special in several ways. First of all, 19757 each of these names up to and including full word size _must_ be 19758 defined, because there is no other way to copy a datum from one 19759 place to another. If there are patterns accepting operands in 19760 larger modes, `movM' must be defined for integer modes of those 19761 sizes. 19762 19763 Second, these patterns are not used solely in the RTL generation 19764 pass. Even the reload pass can generate move insns to copy values 19765 from stack slots into temporary registers. When it does so, one 19766 of the operands is a hard register and the other is an operand 19767 that can need to be reloaded into a register. 19768 19769 Therefore, when given such a pair of operands, the pattern must 19770 generate RTL which needs no reloading and needs no temporary 19771 registers--no registers other than the operands. For example, if 19772 you support the pattern with a `define_expand', then in such a 19773 case the `define_expand' mustn't call `force_reg' or any other such 19774 function which might generate new pseudo registers. 19775 19776 This requirement exists even for subword modes on a RISC machine 19777 where fetching those modes from memory normally requires several 19778 insns and some temporary registers. 19779 19780 During reload a memory reference with an invalid address may be 19781 passed as an operand. Such an address will be replaced with a 19782 valid address later in the reload pass. In this case, nothing may 19783 be done with the address except to use it as it stands. If it is 19784 copied, it will not be replaced with a valid address. No attempt 19785 should be made to make such an address into a valid address and no 19786 routine (such as `change_address') that will do so may be called. 19787 Note that `general_operand' will fail when applied to such an 19788 address. 19789 19790 The global variable `reload_in_progress' (which must be explicitly 19791 declared if required) can be used to determine whether such special 19792 handling is required. 19793 19794 The variety of operands that have reloads depends on the rest of 19795 the machine description, but typically on a RISC machine these can 19796 only be pseudo registers that did not get hard registers, while on 19797 other machines explicit memory references will get optional 19798 reloads. 19799 19800 If a scratch register is required to move an object to or from 19801 memory, it can be allocated using `gen_reg_rtx' prior to life 19802 analysis. 19803 19804 If there are cases which need scratch registers during or after 19805 reload, you must provide an appropriate secondary_reload target 19806 hook. 19807 19808 The macro `can_create_pseudo_p' can be used to determine if it is 19809 unsafe to create new pseudo registers. If this variable is 19810 nonzero, then it is unsafe to call `gen_reg_rtx' to allocate a new 19811 pseudo. 19812 19813 The constraints on a `movM' must permit moving any hard register 19814 to any other hard register provided that `HARD_REGNO_MODE_OK' 19815 permits mode M in both registers and `REGISTER_MOVE_COST' applied 19816 to their classes returns a value of 2. 19817 19818 It is obligatory to support floating point `movM' instructions 19819 into and out of any registers that can hold fixed point values, 19820 because unions and structures (which have modes `SImode' or 19821 `DImode') can be in those registers and they may have floating 19822 point members. 19823 19824 There may also be a need to support fixed point `movM' 19825 instructions in and out of floating point registers. 19826 Unfortunately, I have forgotten why this was so, and I don't know 19827 whether it is still true. If `HARD_REGNO_MODE_OK' rejects fixed 19828 point values in floating point registers, then the constraints of 19829 the fixed point `movM' instructions must be designed to avoid ever 19830 trying to reload into a floating point register. 19831 19832 `reload_inM' 19833 `reload_outM' 19834 These named patterns have been obsoleted by the target hook 19835 `secondary_reload'. 19836 19837 Like `movM', but used when a scratch register is required to move 19838 between operand 0 and operand 1. Operand 2 describes the scratch 19839 register. See the discussion of the `SECONDARY_RELOAD_CLASS' 19840 macro in *note Register Classes::. 19841 19842 There are special restrictions on the form of the `match_operand's 19843 used in these patterns. First, only the predicate for the reload 19844 operand is examined, i.e., `reload_in' examines operand 1, but not 19845 the predicates for operand 0 or 2. Second, there may be only one 19846 alternative in the constraints. Third, only a single register 19847 class letter may be used for the constraint; subsequent constraint 19848 letters are ignored. As a special exception, an empty constraint 19849 string matches the `ALL_REGS' register class. This may relieve 19850 ports of the burden of defining an `ALL_REGS' constraint letter 19851 just for these patterns. 19852 19853 `movstrictM' 19854 Like `movM' except that if operand 0 is a `subreg' with mode M of 19855 a register whose natural mode is wider, the `movstrictM' 19856 instruction is guaranteed not to alter any of the register except 19857 the part which belongs to mode M. 19858 19859 `movmisalignM' 19860 This variant of a move pattern is designed to load or store a value 19861 from a memory address that is not naturally aligned for its mode. 19862 For a store, the memory will be in operand 0; for a load, the 19863 memory will be in operand 1. The other operand is guaranteed not 19864 to be a memory, so that it's easy to tell whether this is a load 19865 or store. 19866 19867 This pattern is used by the autovectorizer, and when expanding a 19868 `MISALIGNED_INDIRECT_REF' expression. 19869 19870 `load_multiple' 19871 Load several consecutive memory locations into consecutive 19872 registers. Operand 0 is the first of the consecutive registers, 19873 operand 1 is the first memory location, and operand 2 is a 19874 constant: the number of consecutive registers. 19875 19876 Define this only if the target machine really has such an 19877 instruction; do not define this if the most efficient way of 19878 loading consecutive registers from memory is to do them one at a 19879 time. 19880 19881 On some machines, there are restrictions as to which consecutive 19882 registers can be stored into memory, such as particular starting or 19883 ending register numbers or only a range of valid counts. For those 19884 machines, use a `define_expand' (*note Expander Definitions::) and 19885 make the pattern fail if the restrictions are not met. 19886 19887 Write the generated insn as a `parallel' with elements being a 19888 `set' of one register from the appropriate memory location (you may 19889 also need `use' or `clobber' elements). Use a `match_parallel' 19890 (*note RTL Template::) to recognize the insn. See `rs6000.md' for 19891 examples of the use of this insn pattern. 19892 19893 `store_multiple' 19894 Similar to `load_multiple', but store several consecutive registers 19895 into consecutive memory locations. Operand 0 is the first of the 19896 consecutive memory locations, operand 1 is the first register, and 19897 operand 2 is a constant: the number of consecutive registers. 19898 19899 `vec_setM' 19900 Set given field in the vector value. Operand 0 is the vector to 19901 modify, operand 1 is new value of field and operand 2 specify the 19902 field index. 19903 19904 `vec_extractM' 19905 Extract given field from the vector value. Operand 1 is the 19906 vector, operand 2 specify field index and operand 0 place to store 19907 value into. 19908 19909 `vec_extract_evenM' 19910 Extract even elements from the input vectors (operand 1 and 19911 operand 2). The even elements of operand 2 are concatenated to 19912 the even elements of operand 1 in their original order. The result 19913 is stored in operand 0. The output and input vectors should have 19914 the same modes. 19915 19916 `vec_extract_oddM' 19917 Extract odd elements from the input vectors (operand 1 and operand 19918 2). The odd elements of operand 2 are concatenated to the odd 19919 elements of operand 1 in their original order. The result is 19920 stored in operand 0. The output and input vectors should have the 19921 same modes. 19922 19923 `vec_interleave_highM' 19924 Merge high elements of the two input vectors into the output 19925 vector. The output and input vectors should have the same modes 19926 (`N' elements). The high `N/2' elements of the first input vector 19927 are interleaved with the high `N/2' elements of the second input 19928 vector. 19929 19930 `vec_interleave_lowM' 19931 Merge low elements of the two input vectors into the output 19932 vector. The output and input vectors should have the same modes 19933 (`N' elements). The low `N/2' elements of the first input vector 19934 are interleaved with the low `N/2' elements of the second input 19935 vector. 19936 19937 `vec_initM' 19938 Initialize the vector to given values. Operand 0 is the vector to 19939 initialize and operand 1 is parallel containing values for 19940 individual fields. 19941 19942 `pushM1' 19943 Output a push instruction. Operand 0 is value to push. Used only 19944 when `PUSH_ROUNDING' is defined. For historical reason, this 19945 pattern may be missing and in such case an `mov' expander is used 19946 instead, with a `MEM' expression forming the push operation. The 19947 `mov' expander method is deprecated. 19948 19949 `addM3' 19950 Add operand 2 and operand 1, storing the result in operand 0. All 19951 operands must have mode M. This can be used even on two-address 19952 machines, by means of constraints requiring operands 1 and 0 to be 19953 the same location. 19954 19955 `ssaddM3', `usaddM3' 19956 19957 `subM3', `sssubM3', `ussubM3' 19958 19959 `mulM3', `ssmulM3', `usmulM3' 19960 `divM3', `ssdivM3' 19961 `udivM3', `usdivM3' 19962 `modM3', `umodM3' 19963 `uminM3', `umaxM3' 19964 `andM3', `iorM3', `xorM3' 19965 Similar, for other arithmetic operations. 19966 19967 `sminM3', `smaxM3' 19968 Signed minimum and maximum operations. When used with floating 19969 point, if both operands are zeros, or if either operand is `NaN', 19970 then it is unspecified which of the two operands is returned as 19971 the result. 19972 19973 `reduc_smin_M', `reduc_smax_M' 19974 Find the signed minimum/maximum of the elements of a vector. The 19975 vector is operand 1, and the scalar result is stored in the least 19976 significant bits of operand 0 (also a vector). The output and 19977 input vector should have the same modes. 19978 19979 `reduc_umin_M', `reduc_umax_M' 19980 Find the unsigned minimum/maximum of the elements of a vector. The 19981 vector is operand 1, and the scalar result is stored in the least 19982 significant bits of operand 0 (also a vector). The output and 19983 input vector should have the same modes. 19984 19985 `reduc_splus_M' 19986 Compute the sum of the signed elements of a vector. The vector is 19987 operand 1, and the scalar result is stored in the least 19988 significant bits of operand 0 (also a vector). The output and 19989 input vector should have the same modes. 19990 19991 `reduc_uplus_M' 19992 Compute the sum of the unsigned elements of a vector. The vector 19993 is operand 1, and the scalar result is stored in the least 19994 significant bits of operand 0 (also a vector). The output and 19995 input vector should have the same modes. 19996 19997 `sdot_prodM' 19998 19999 `udot_prodM' 20000 Compute the sum of the products of two signed/unsigned elements. 20001 Operand 1 and operand 2 are of the same mode. Their product, which 20002 is of a wider mode, is computed and added to operand 3. Operand 3 20003 is of a mode equal or wider than the mode of the product. The 20004 result is placed in operand 0, which is of the same mode as 20005 operand 3. 20006 20007 `ssum_widenM3' 20008 20009 `usum_widenM3' 20010 Operands 0 and 2 are of the same mode, which is wider than the 20011 mode of operand 1. Add operand 1 to operand 2 and place the 20012 widened result in operand 0. (This is used express accumulation of 20013 elements into an accumulator of a wider mode.) 20014 20015 `vec_shl_M', `vec_shr_M' 20016 Whole vector left/right shift in bits. Operand 1 is a vector to 20017 be shifted. Operand 2 is an integer shift amount in bits. 20018 Operand 0 is where the resulting shifted vector is stored. The 20019 output and input vectors should have the same modes. 20020 20021 `vec_pack_trunc_M' 20022 Narrow (demote) and merge the elements of two vectors. Operands 1 20023 and 2 are vectors of the same mode having N integral or floating 20024 point elements of size S. Operand 0 is the resulting vector in 20025 which 2*N elements of size N/2 are concatenated after narrowing 20026 them down using truncation. 20027 20028 `vec_pack_ssat_M', `vec_pack_usat_M' 20029 Narrow (demote) and merge the elements of two vectors. Operands 1 20030 and 2 are vectors of the same mode having N integral elements of 20031 size S. Operand 0 is the resulting vector in which the elements 20032 of the two input vectors are concatenated after narrowing them 20033 down using signed/unsigned saturating arithmetic. 20034 20035 `vec_pack_sfix_trunc_M', `vec_pack_ufix_trunc_M' 20036 Narrow, convert to signed/unsigned integral type and merge the 20037 elements of two vectors. Operands 1 and 2 are vectors of the same 20038 mode having N floating point elements of size S. Operand 0 is the 20039 resulting vector in which 2*N elements of size N/2 are 20040 concatenated. 20041 20042 `vec_unpacks_hi_M', `vec_unpacks_lo_M' 20043 Extract and widen (promote) the high/low part of a vector of signed 20044 integral or floating point elements. The input vector (operand 1) 20045 has N elements of size S. Widen (promote) the high/low elements 20046 of the vector using signed or floating point extension and place 20047 the resulting N/2 values of size 2*S in the output vector (operand 20048 0). 20049 20050 `vec_unpacku_hi_M', `vec_unpacku_lo_M' 20051 Extract and widen (promote) the high/low part of a vector of 20052 unsigned integral elements. The input vector (operand 1) has N 20053 elements of size S. Widen (promote) the high/low elements of the 20054 vector using zero extension and place the resulting N/2 values of 20055 size 2*S in the output vector (operand 0). 20056 20057 `vec_unpacks_float_hi_M', `vec_unpacks_float_lo_M' 20058 `vec_unpacku_float_hi_M', `vec_unpacku_float_lo_M' 20059 Extract, convert to floating point type and widen the high/low 20060 part of a vector of signed/unsigned integral elements. The input 20061 vector (operand 1) has N elements of size S. Convert the high/low 20062 elements of the vector using floating point conversion and place 20063 the resulting N/2 values of size 2*S in the output vector (operand 20064 0). 20065 20066 `vec_widen_umult_hi_M', `vec_widen_umult_lo_M' 20067 `vec_widen_smult_hi_M', `vec_widen_smult_lo_M' 20068 Signed/Unsigned widening multiplication. The two inputs (operands 20069 1 and 2) are vectors with N signed/unsigned elements of size S. 20070 Multiply the high/low elements of the two vectors, and put the N/2 20071 products of size 2*S in the output vector (operand 0). 20072 20073 `mulhisi3' 20074 Multiply operands 1 and 2, which have mode `HImode', and store a 20075 `SImode' product in operand 0. 20076 20077 `mulqihi3', `mulsidi3' 20078 Similar widening-multiplication instructions of other widths. 20079 20080 `umulqihi3', `umulhisi3', `umulsidi3' 20081 Similar widening-multiplication instructions that do unsigned 20082 multiplication. 20083 20084 `usmulqihi3', `usmulhisi3', `usmulsidi3' 20085 Similar widening-multiplication instructions that interpret the 20086 first operand as unsigned and the second operand as signed, then 20087 do a signed multiplication. 20088 20089 `smulM3_highpart' 20090 Perform a signed multiplication of operands 1 and 2, which have 20091 mode M, and store the most significant half of the product in 20092 operand 0. The least significant half of the product is discarded. 20093 20094 `umulM3_highpart' 20095 Similar, but the multiplication is unsigned. 20096 20097 `maddMN4' 20098 Multiply operands 1 and 2, sign-extend them to mode N, add operand 20099 3, and store the result in operand 0. Operands 1 and 2 have mode 20100 M and operands 0 and 3 have mode N. Both modes must be integer or 20101 fixed-point modes and N must be twice the size of M. 20102 20103 In other words, `maddMN4' is like `mulMN3' except that it also 20104 adds operand 3. 20105 20106 These instructions are not allowed to `FAIL'. 20107 20108 `umaddMN4' 20109 Like `maddMN4', but zero-extend the multiplication operands 20110 instead of sign-extending them. 20111 20112 `ssmaddMN4' 20113 Like `maddMN4', but all involved operations must be 20114 signed-saturating. 20115 20116 `usmaddMN4' 20117 Like `umaddMN4', but all involved operations must be 20118 unsigned-saturating. 20119 20120 `msubMN4' 20121 Multiply operands 1 and 2, sign-extend them to mode N, subtract the 20122 result from operand 3, and store the result in operand 0. 20123 Operands 1 and 2 have mode M and operands 0 and 3 have mode N. 20124 Both modes must be integer or fixed-point modes and N must be twice 20125 the size of M. 20126 20127 In other words, `msubMN4' is like `mulMN3' except that it also 20128 subtracts the result from operand 3. 20129 20130 These instructions are not allowed to `FAIL'. 20131 20132 `umsubMN4' 20133 Like `msubMN4', but zero-extend the multiplication operands 20134 instead of sign-extending them. 20135 20136 `ssmsubMN4' 20137 Like `msubMN4', but all involved operations must be 20138 signed-saturating. 20139 20140 `usmsubMN4' 20141 Like `umsubMN4', but all involved operations must be 20142 unsigned-saturating. 20143 20144 `divmodM4' 20145 Signed division that produces both a quotient and a remainder. 20146 Operand 1 is divided by operand 2 to produce a quotient stored in 20147 operand 0 and a remainder stored in operand 3. 20148 20149 For machines with an instruction that produces both a quotient and 20150 a remainder, provide a pattern for `divmodM4' but do not provide 20151 patterns for `divM3' and `modM3'. This allows optimization in the 20152 relatively common case when both the quotient and remainder are 20153 computed. 20154 20155 If an instruction that just produces a quotient or just a remainder 20156 exists and is more efficient than the instruction that produces 20157 both, write the output routine of `divmodM4' to call 20158 `find_reg_note' and look for a `REG_UNUSED' note on the quotient 20159 or remainder and generate the appropriate instruction. 20160 20161 `udivmodM4' 20162 Similar, but does unsigned division. 20163 20164 `ashlM3', `ssashlM3', `usashlM3' 20165 Arithmetic-shift operand 1 left by a number of bits specified by 20166 operand 2, and store the result in operand 0. Here M is the mode 20167 of operand 0 and operand 1; operand 2's mode is specified by the 20168 instruction pattern, and the compiler will convert the operand to 20169 that mode before generating the instruction. The meaning of 20170 out-of-range shift counts can optionally be specified by 20171 `TARGET_SHIFT_TRUNCATION_MASK'. *Note 20172 TARGET_SHIFT_TRUNCATION_MASK::. Operand 2 is always a scalar type. 20173 20174 `ashrM3', `lshrM3', `rotlM3', `rotrM3' 20175 Other shift and rotate instructions, analogous to the `ashlM3' 20176 instructions. Operand 2 is always a scalar type. 20177 20178 `vashlM3', `vashrM3', `vlshrM3', `vrotlM3', `vrotrM3' 20179 Vector shift and rotate instructions that take vectors as operand 2 20180 instead of a scalar type. 20181 20182 `negM2', `ssnegM2', `usnegM2' 20183 Negate operand 1 and store the result in operand 0. 20184 20185 `absM2' 20186 Store the absolute value of operand 1 into operand 0. 20187 20188 `sqrtM2' 20189 Store the square root of operand 1 into operand 0. 20190 20191 The `sqrt' built-in function of C always uses the mode which 20192 corresponds to the C data type `double' and the `sqrtf' built-in 20193 function uses the mode which corresponds to the C data type 20194 `float'. 20195 20196 `fmodM3' 20197 Store the remainder of dividing operand 1 by operand 2 into 20198 operand 0, rounded towards zero to an integer. 20199 20200 The `fmod' built-in function of C always uses the mode which 20201 corresponds to the C data type `double' and the `fmodf' built-in 20202 function uses the mode which corresponds to the C data type 20203 `float'. 20204 20205 `remainderM3' 20206 Store the remainder of dividing operand 1 by operand 2 into 20207 operand 0, rounded to the nearest integer. 20208 20209 The `remainder' built-in function of C always uses the mode which 20210 corresponds to the C data type `double' and the `remainderf' 20211 built-in function uses the mode which corresponds to the C data 20212 type `float'. 20213 20214 `cosM2' 20215 Store the cosine of operand 1 into operand 0. 20216 20217 The `cos' built-in function of C always uses the mode which 20218 corresponds to the C data type `double' and the `cosf' built-in 20219 function uses the mode which corresponds to the C data type 20220 `float'. 20221 20222 `sinM2' 20223 Store the sine of operand 1 into operand 0. 20224 20225 The `sin' built-in function of C always uses the mode which 20226 corresponds to the C data type `double' and the `sinf' built-in 20227 function uses the mode which corresponds to the C data type 20228 `float'. 20229 20230 `expM2' 20231 Store the exponential of operand 1 into operand 0. 20232 20233 The `exp' built-in function of C always uses the mode which 20234 corresponds to the C data type `double' and the `expf' built-in 20235 function uses the mode which corresponds to the C data type 20236 `float'. 20237 20238 `logM2' 20239 Store the natural logarithm of operand 1 into operand 0. 20240 20241 The `log' built-in function of C always uses the mode which 20242 corresponds to the C data type `double' and the `logf' built-in 20243 function uses the mode which corresponds to the C data type 20244 `float'. 20245 20246 `powM3' 20247 Store the value of operand 1 raised to the exponent operand 2 into 20248 operand 0. 20249 20250 The `pow' built-in function of C always uses the mode which 20251 corresponds to the C data type `double' and the `powf' built-in 20252 function uses the mode which corresponds to the C data type 20253 `float'. 20254 20255 `atan2M3' 20256 Store the arc tangent (inverse tangent) of operand 1 divided by 20257 operand 2 into operand 0, using the signs of both arguments to 20258 determine the quadrant of the result. 20259 20260 The `atan2' built-in function of C always uses the mode which 20261 corresponds to the C data type `double' and the `atan2f' built-in 20262 function uses the mode which corresponds to the C data type 20263 `float'. 20264 20265 `floorM2' 20266 Store the largest integral value not greater than argument. 20267 20268 The `floor' built-in function of C always uses the mode which 20269 corresponds to the C data type `double' and the `floorf' built-in 20270 function uses the mode which corresponds to the C data type 20271 `float'. 20272 20273 `btruncM2' 20274 Store the argument rounded to integer towards zero. 20275 20276 The `trunc' built-in function of C always uses the mode which 20277 corresponds to the C data type `double' and the `truncf' built-in 20278 function uses the mode which corresponds to the C data type 20279 `float'. 20280 20281 `roundM2' 20282 Store the argument rounded to integer away from zero. 20283 20284 The `round' built-in function of C always uses the mode which 20285 corresponds to the C data type `double' and the `roundf' built-in 20286 function uses the mode which corresponds to the C data type 20287 `float'. 20288 20289 `ceilM2' 20290 Store the argument rounded to integer away from zero. 20291 20292 The `ceil' built-in function of C always uses the mode which 20293 corresponds to the C data type `double' and the `ceilf' built-in 20294 function uses the mode which corresponds to the C data type 20295 `float'. 20296 20297 `nearbyintM2' 20298 Store the argument rounded according to the default rounding mode 20299 20300 The `nearbyint' built-in function of C always uses the mode which 20301 corresponds to the C data type `double' and the `nearbyintf' 20302 built-in function uses the mode which corresponds to the C data 20303 type `float'. 20304 20305 `rintM2' 20306 Store the argument rounded according to the default rounding mode 20307 and raise the inexact exception when the result differs in value 20308 from the argument 20309 20310 The `rint' built-in function of C always uses the mode which 20311 corresponds to the C data type `double' and the `rintf' built-in 20312 function uses the mode which corresponds to the C data type 20313 `float'. 20314 20315 `lrintMN2' 20316 Convert operand 1 (valid for floating point mode M) to fixed point 20317 mode N as a signed number according to the current rounding mode 20318 and store in operand 0 (which has mode N). 20319 20320 `lroundM2' 20321 Convert operand 1 (valid for floating point mode M) to fixed point 20322 mode N as a signed number rounding to nearest and away from zero 20323 and store in operand 0 (which has mode N). 20324 20325 `lfloorM2' 20326 Convert operand 1 (valid for floating point mode M) to fixed point 20327 mode N as a signed number rounding down and store in operand 0 20328 (which has mode N). 20329 20330 `lceilM2' 20331 Convert operand 1 (valid for floating point mode M) to fixed point 20332 mode N as a signed number rounding up and store in operand 0 20333 (which has mode N). 20334 20335 `copysignM3' 20336 Store a value with the magnitude of operand 1 and the sign of 20337 operand 2 into operand 0. 20338 20339 The `copysign' built-in function of C always uses the mode which 20340 corresponds to the C data type `double' and the `copysignf' 20341 built-in function uses the mode which corresponds to the C data 20342 type `float'. 20343 20344 `ffsM2' 20345 Store into operand 0 one plus the index of the least significant 20346 1-bit of operand 1. If operand 1 is zero, store zero. M is the 20347 mode of operand 0; operand 1's mode is specified by the instruction 20348 pattern, and the compiler will convert the operand to that mode 20349 before generating the instruction. 20350 20351 The `ffs' built-in function of C always uses the mode which 20352 corresponds to the C data type `int'. 20353 20354 `clzM2' 20355 Store into operand 0 the number of leading 0-bits in X, starting 20356 at the most significant bit position. If X is 0, the 20357 `CLZ_DEFINED_VALUE_AT_ZERO' (*note Misc::) macro defines if the 20358 result is undefined or has a useful value. M is the mode of 20359 operand 0; operand 1's mode is specified by the instruction 20360 pattern, and the compiler will convert the operand to that mode 20361 before generating the instruction. 20362 20363 `ctzM2' 20364 Store into operand 0 the number of trailing 0-bits in X, starting 20365 at the least significant bit position. If X is 0, the 20366 `CTZ_DEFINED_VALUE_AT_ZERO' (*note Misc::) macro defines if the 20367 result is undefined or has a useful value. M is the mode of 20368 operand 0; operand 1's mode is specified by the instruction 20369 pattern, and the compiler will convert the operand to that mode 20370 before generating the instruction. 20371 20372 `popcountM2' 20373 Store into operand 0 the number of 1-bits in X. M is the mode of 20374 operand 0; operand 1's mode is specified by the instruction 20375 pattern, and the compiler will convert the operand to that mode 20376 before generating the instruction. 20377 20378 `parityM2' 20379 Store into operand 0 the parity of X, i.e. the number of 1-bits in 20380 X modulo 2. M is the mode of operand 0; operand 1's mode is 20381 specified by the instruction pattern, and the compiler will convert 20382 the operand to that mode before generating the instruction. 20383 20384 `one_cmplM2' 20385 Store the bitwise-complement of operand 1 into operand 0. 20386 20387 `cmpM' 20388 Compare operand 0 and operand 1, and set the condition codes. The 20389 RTL pattern should look like this: 20390 20391 (set (cc0) (compare (match_operand:M 0 ...) 20392 (match_operand:M 1 ...))) 20393 20394 `tstM' 20395 Compare operand 0 against zero, and set the condition codes. The 20396 RTL pattern should look like this: 20397 20398 (set (cc0) (match_operand:M 0 ...)) 20399 20400 `tstM' patterns should not be defined for machines that do not use 20401 `(cc0)'. Doing so would confuse the optimizer since it would no 20402 longer be clear which `set' operations were comparisons. The 20403 `cmpM' patterns should be used instead. 20404 20405 `movmemM' 20406 Block move instruction. The destination and source blocks of 20407 memory are the first two operands, and both are `mem:BLK's with an 20408 address in mode `Pmode'. 20409 20410 The number of bytes to move is the third operand, in mode M. 20411 Usually, you specify `word_mode' for M. However, if you can 20412 generate better code knowing the range of valid lengths is smaller 20413 than those representable in a full word, you should provide a 20414 pattern with a mode corresponding to the range of values you can 20415 handle efficiently (e.g., `QImode' for values in the range 0-127; 20416 note we avoid numbers that appear negative) and also a pattern 20417 with `word_mode'. 20418 20419 The fourth operand is the known shared alignment of the source and 20420 destination, in the form of a `const_int' rtx. Thus, if the 20421 compiler knows that both source and destination are word-aligned, 20422 it may provide the value 4 for this operand. 20423 20424 Optional operands 5 and 6 specify expected alignment and size of 20425 block respectively. The expected alignment differs from alignment 20426 in operand 4 in a way that the blocks are not required to be 20427 aligned according to it in all cases. This expected alignment is 20428 also in bytes, just like operand 4. Expected size, when unknown, 20429 is set to `(const_int -1)'. 20430 20431 Descriptions of multiple `movmemM' patterns can only be beneficial 20432 if the patterns for smaller modes have fewer restrictions on their 20433 first, second and fourth operands. Note that the mode M in 20434 `movmemM' does not impose any restriction on the mode of 20435 individually moved data units in the block. 20436 20437 These patterns need not give special consideration to the 20438 possibility that the source and destination strings might overlap. 20439 20440 `movstr' 20441 String copy instruction, with `stpcpy' semantics. Operand 0 is an 20442 output operand in mode `Pmode'. The addresses of the destination 20443 and source strings are operands 1 and 2, and both are `mem:BLK's 20444 with addresses in mode `Pmode'. The execution of the expansion of 20445 this pattern should store in operand 0 the address in which the 20446 `NUL' terminator was stored in the destination string. 20447 20448 `setmemM' 20449 Block set instruction. The destination string is the first 20450 operand, given as a `mem:BLK' whose address is in mode `Pmode'. 20451 The number of bytes to set is the second operand, in mode M. The 20452 value to initialize the memory with is the third operand. Targets 20453 that only support the clearing of memory should reject any value 20454 that is not the constant 0. See `movmemM' for a discussion of the 20455 choice of mode. 20456 20457 The fourth operand is the known alignment of the destination, in 20458 the form of a `const_int' rtx. Thus, if the compiler knows that 20459 the destination is word-aligned, it may provide the value 4 for 20460 this operand. 20461 20462 Optional operands 5 and 6 specify expected alignment and size of 20463 block respectively. The expected alignment differs from alignment 20464 in operand 4 in a way that the blocks are not required to be 20465 aligned according to it in all cases. This expected alignment is 20466 also in bytes, just like operand 4. Expected size, when unknown, 20467 is set to `(const_int -1)'. 20468 20469 The use for multiple `setmemM' is as for `movmemM'. 20470 20471 `cmpstrnM' 20472 String compare instruction, with five operands. Operand 0 is the 20473 output; it has mode M. The remaining four operands are like the 20474 operands of `movmemM'. The two memory blocks specified are 20475 compared byte by byte in lexicographic order starting at the 20476 beginning of each string. The instruction is not allowed to 20477 prefetch more than one byte at a time since either string may end 20478 in the first byte and reading past that may access an invalid page 20479 or segment and cause a fault. The effect of the instruction is to 20480 store a value in operand 0 whose sign indicates the result of the 20481 comparison. 20482 20483 `cmpstrM' 20484 String compare instruction, without known maximum length. Operand 20485 0 is the output; it has mode M. The second and third operand are 20486 the blocks of memory to be compared; both are `mem:BLK' with an 20487 address in mode `Pmode'. 20488 20489 The fourth operand is the known shared alignment of the source and 20490 destination, in the form of a `const_int' rtx. Thus, if the 20491 compiler knows that both source and destination are word-aligned, 20492 it may provide the value 4 for this operand. 20493 20494 The two memory blocks specified are compared byte by byte in 20495 lexicographic order starting at the beginning of each string. The 20496 instruction is not allowed to prefetch more than one byte at a 20497 time since either string may end in the first byte and reading 20498 past that may access an invalid page or segment and cause a fault. 20499 The effect of the instruction is to store a value in operand 0 20500 whose sign indicates the result of the comparison. 20501 20502 `cmpmemM' 20503 Block compare instruction, with five operands like the operands of 20504 `cmpstrM'. The two memory blocks specified are compared byte by 20505 byte in lexicographic order starting at the beginning of each 20506 block. Unlike `cmpstrM' the instruction can prefetch any bytes in 20507 the two memory blocks. The effect of the instruction is to store 20508 a value in operand 0 whose sign indicates the result of the 20509 comparison. 20510 20511 `strlenM' 20512 Compute the length of a string, with three operands. Operand 0 is 20513 the result (of mode M), operand 1 is a `mem' referring to the 20514 first character of the string, operand 2 is the character to 20515 search for (normally zero), and operand 3 is a constant describing 20516 the known alignment of the beginning of the string. 20517 20518 `floatMN2' 20519 Convert signed integer operand 1 (valid for fixed point mode M) to 20520 floating point mode N and store in operand 0 (which has mode N). 20521 20522 `floatunsMN2' 20523 Convert unsigned integer operand 1 (valid for fixed point mode M) 20524 to floating point mode N and store in operand 0 (which has mode N). 20525 20526 `fixMN2' 20527 Convert operand 1 (valid for floating point mode M) to fixed point 20528 mode N as a signed number and store in operand 0 (which has mode 20529 N). This instruction's result is defined only when the value of 20530 operand 1 is an integer. 20531 20532 If the machine description defines this pattern, it also needs to 20533 define the `ftrunc' pattern. 20534 20535 `fixunsMN2' 20536 Convert operand 1 (valid for floating point mode M) to fixed point 20537 mode N as an unsigned number and store in operand 0 (which has 20538 mode N). This instruction's result is defined only when the value 20539 of operand 1 is an integer. 20540 20541 `ftruncM2' 20542 Convert operand 1 (valid for floating point mode M) to an integer 20543 value, still represented in floating point mode M, and store it in 20544 operand 0 (valid for floating point mode M). 20545 20546 `fix_truncMN2' 20547 Like `fixMN2' but works for any floating point value of mode M by 20548 converting the value to an integer. 20549 20550 `fixuns_truncMN2' 20551 Like `fixunsMN2' but works for any floating point value of mode M 20552 by converting the value to an integer. 20553 20554 `truncMN2' 20555 Truncate operand 1 (valid for mode M) to mode N and store in 20556 operand 0 (which has mode N). Both modes must be fixed point or 20557 both floating point. 20558 20559 `extendMN2' 20560 Sign-extend operand 1 (valid for mode M) to mode N and store in 20561 operand 0 (which has mode N). Both modes must be fixed point or 20562 both floating point. 20563 20564 `zero_extendMN2' 20565 Zero-extend operand 1 (valid for mode M) to mode N and store in 20566 operand 0 (which has mode N). Both modes must be fixed point. 20567 20568 `fractMN2' 20569 Convert operand 1 of mode M to mode N and store in operand 0 20570 (which has mode N). Mode M and mode N could be fixed-point to 20571 fixed-point, signed integer to fixed-point, fixed-point to signed 20572 integer, floating-point to fixed-point, or fixed-point to 20573 floating-point. When overflows or underflows happen, the results 20574 are undefined. 20575 20576 `satfractMN2' 20577 Convert operand 1 of mode M to mode N and store in operand 0 20578 (which has mode N). Mode M and mode N could be fixed-point to 20579 fixed-point, signed integer to fixed-point, or floating-point to 20580 fixed-point. When overflows or underflows happen, the instruction 20581 saturates the results to the maximum or the minimum. 20582 20583 `fractunsMN2' 20584 Convert operand 1 of mode M to mode N and store in operand 0 20585 (which has mode N). Mode M and mode N could be unsigned integer 20586 to fixed-point, or fixed-point to unsigned integer. When 20587 overflows or underflows happen, the results are undefined. 20588 20589 `satfractunsMN2' 20590 Convert unsigned integer operand 1 of mode M to fixed-point mode N 20591 and store in operand 0 (which has mode N). When overflows or 20592 underflows happen, the instruction saturates the results to the 20593 maximum or the minimum. 20594 20595 `extv' 20596 Extract a bit-field from operand 1 (a register or memory operand), 20597 where operand 2 specifies the width in bits and operand 3 the 20598 starting bit, and store it in operand 0. Operand 0 must have mode 20599 `word_mode'. Operand 1 may have mode `byte_mode' or `word_mode'; 20600 often `word_mode' is allowed only for registers. Operands 2 and 3 20601 must be valid for `word_mode'. 20602 20603 The RTL generation pass generates this instruction only with 20604 constants for operands 2 and 3 and the constant is never zero for 20605 operand 2. 20606 20607 The bit-field value is sign-extended to a full word integer before 20608 it is stored in operand 0. 20609 20610 `extzv' 20611 Like `extv' except that the bit-field value is zero-extended. 20612 20613 `insv' 20614 Store operand 3 (which must be valid for `word_mode') into a 20615 bit-field in operand 0, where operand 1 specifies the width in 20616 bits and operand 2 the starting bit. Operand 0 may have mode 20617 `byte_mode' or `word_mode'; often `word_mode' is allowed only for 20618 registers. Operands 1 and 2 must be valid for `word_mode'. 20619 20620 The RTL generation pass generates this instruction only with 20621 constants for operands 1 and 2 and the constant is never zero for 20622 operand 1. 20623 20624 `movMODEcc' 20625 Conditionally move operand 2 or operand 3 into operand 0 according 20626 to the comparison in operand 1. If the comparison is true, 20627 operand 2 is moved into operand 0, otherwise operand 3 is moved. 20628 20629 The mode of the operands being compared need not be the same as 20630 the operands being moved. Some machines, sparc64 for example, 20631 have instructions that conditionally move an integer value based 20632 on the floating point condition codes and vice versa. 20633 20634 If the machine does not have conditional move instructions, do not 20635 define these patterns. 20636 20637 `addMODEcc' 20638 Similar to `movMODEcc' but for conditional addition. Conditionally 20639 move operand 2 or (operands 2 + operand 3) into operand 0 20640 according to the comparison in operand 1. If the comparison is 20641 true, operand 2 is moved into operand 0, otherwise (operand 2 + 20642 operand 3) is moved. 20643 20644 `sCOND' 20645 Store zero or nonzero in the operand according to the condition 20646 codes. Value stored is nonzero iff the condition COND is true. 20647 COND is the name of a comparison operation expression code, such 20648 as `eq', `lt' or `leu'. 20649 20650 You specify the mode that the operand must have when you write the 20651 `match_operand' expression. The compiler automatically sees which 20652 mode you have used and supplies an operand of that mode. 20653 20654 The value stored for a true condition must have 1 as its low bit, 20655 or else must be negative. Otherwise the instruction is not 20656 suitable and you should omit it from the machine description. You 20657 describe to the compiler exactly which value is stored by defining 20658 the macro `STORE_FLAG_VALUE' (*note Misc::). If a description 20659 cannot be found that can be used for all the `sCOND' patterns, you 20660 should omit those operations from the machine description. 20661 20662 These operations may fail, but should do so only in relatively 20663 uncommon cases; if they would fail for common cases involving 20664 integer comparisons, it is best to omit these patterns. 20665 20666 If these operations are omitted, the compiler will usually 20667 generate code that copies the constant one to the target and 20668 branches around an assignment of zero to the target. If this code 20669 is more efficient than the potential instructions used for the 20670 `sCOND' pattern followed by those required to convert the result 20671 into a 1 or a zero in `SImode', you should omit the `sCOND' 20672 operations from the machine description. 20673 20674 `bCOND' 20675 Conditional branch instruction. Operand 0 is a `label_ref' that 20676 refers to the label to jump to. Jump if the condition codes meet 20677 condition COND. 20678 20679 Some machines do not follow the model assumed here where a 20680 comparison instruction is followed by a conditional branch 20681 instruction. In that case, the `cmpM' (and `tstM') patterns should 20682 simply store the operands away and generate all the required insns 20683 in a `define_expand' (*note Expander Definitions::) for the 20684 conditional branch operations. All calls to expand `bCOND' 20685 patterns are immediately preceded by calls to expand either a 20686 `cmpM' pattern or a `tstM' pattern. 20687 20688 Machines that use a pseudo register for the condition code value, 20689 or where the mode used for the comparison depends on the condition 20690 being tested, should also use the above mechanism. *Note Jump 20691 Patterns::. 20692 20693 The above discussion also applies to the `movMODEcc' and `sCOND' 20694 patterns. 20695 20696 `cbranchMODE4' 20697 Conditional branch instruction combined with a compare instruction. 20698 Operand 0 is a comparison operator. Operand 1 and operand 2 are 20699 the first and second operands of the comparison, respectively. 20700 Operand 3 is a `label_ref' that refers to the label to jump to. 20701 20702 `jump' 20703 A jump inside a function; an unconditional branch. Operand 0 is 20704 the `label_ref' of the label to jump to. This pattern name is 20705 mandatory on all machines. 20706 20707 `call' 20708 Subroutine call instruction returning no value. Operand 0 is the 20709 function to call; operand 1 is the number of bytes of arguments 20710 pushed as a `const_int'; operand 2 is the number of registers used 20711 as operands. 20712 20713 On most machines, operand 2 is not actually stored into the RTL 20714 pattern. It is supplied for the sake of some RISC machines which 20715 need to put this information into the assembler code; they can put 20716 it in the RTL instead of operand 1. 20717 20718 Operand 0 should be a `mem' RTX whose address is the address of the 20719 function. Note, however, that this address can be a `symbol_ref' 20720 expression even if it would not be a legitimate memory address on 20721 the target machine. If it is also not a valid argument for a call 20722 instruction, the pattern for this operation should be a 20723 `define_expand' (*note Expander Definitions::) that places the 20724 address into a register and uses that register in the call 20725 instruction. 20726 20727 `call_value' 20728 Subroutine call instruction returning a value. Operand 0 is the 20729 hard register in which the value is returned. There are three more 20730 operands, the same as the three operands of the `call' instruction 20731 (but with numbers increased by one). 20732 20733 Subroutines that return `BLKmode' objects use the `call' insn. 20734 20735 `call_pop', `call_value_pop' 20736 Similar to `call' and `call_value', except used if defined and if 20737 `RETURN_POPS_ARGS' is nonzero. They should emit a `parallel' that 20738 contains both the function call and a `set' to indicate the 20739 adjustment made to the frame pointer. 20740 20741 For machines where `RETURN_POPS_ARGS' can be nonzero, the use of 20742 these patterns increases the number of functions for which the 20743 frame pointer can be eliminated, if desired. 20744 20745 `untyped_call' 20746 Subroutine call instruction returning a value of any type. 20747 Operand 0 is the function to call; operand 1 is a memory location 20748 where the result of calling the function is to be stored; operand 20749 2 is a `parallel' expression where each element is a `set' 20750 expression that indicates the saving of a function return value 20751 into the result block. 20752 20753 This instruction pattern should be defined to support 20754 `__builtin_apply' on machines where special instructions are needed 20755 to call a subroutine with arbitrary arguments or to save the value 20756 returned. This instruction pattern is required on machines that 20757 have multiple registers that can hold a return value (i.e. 20758 `FUNCTION_VALUE_REGNO_P' is true for more than one register). 20759 20760 `return' 20761 Subroutine return instruction. This instruction pattern name 20762 should be defined only if a single instruction can do all the work 20763 of returning from a function. 20764 20765 Like the `movM' patterns, this pattern is also used after the RTL 20766 generation phase. In this case it is to support machines where 20767 multiple instructions are usually needed to return from a 20768 function, but some class of functions only requires one 20769 instruction to implement a return. Normally, the applicable 20770 functions are those which do not need to save any registers or 20771 allocate stack space. 20772 20773 For such machines, the condition specified in this pattern should 20774 only be true when `reload_completed' is nonzero and the function's 20775 epilogue would only be a single instruction. For machines with 20776 register windows, the routine `leaf_function_p' may be used to 20777 determine if a register window push is required. 20778 20779 Machines that have conditional return instructions should define 20780 patterns such as 20781 20782 (define_insn "" 20783 [(set (pc) 20784 (if_then_else (match_operator 20785 0 "comparison_operator" 20786 [(cc0) (const_int 0)]) 20787 (return) 20788 (pc)))] 20789 "CONDITION" 20790 "...") 20791 20792 where CONDITION would normally be the same condition specified on 20793 the named `return' pattern. 20794 20795 `untyped_return' 20796 Untyped subroutine return instruction. This instruction pattern 20797 should be defined to support `__builtin_return' on machines where 20798 special instructions are needed to return a value of any type. 20799 20800 Operand 0 is a memory location where the result of calling a 20801 function with `__builtin_apply' is stored; operand 1 is a 20802 `parallel' expression where each element is a `set' expression 20803 that indicates the restoring of a function return value from the 20804 result block. 20805 20806 `nop' 20807 No-op instruction. This instruction pattern name should always be 20808 defined to output a no-op in assembler code. `(const_int 0)' will 20809 do as an RTL pattern. 20810 20811 `indirect_jump' 20812 An instruction to jump to an address which is operand zero. This 20813 pattern name is mandatory on all machines. 20814 20815 `casesi' 20816 Instruction to jump through a dispatch table, including bounds 20817 checking. This instruction takes five operands: 20818 20819 1. The index to dispatch on, which has mode `SImode'. 20820 20821 2. The lower bound for indices in the table, an integer constant. 20822 20823 3. The total range of indices in the table--the largest index 20824 minus the smallest one (both inclusive). 20825 20826 4. A label that precedes the table itself. 20827 20828 5. A label to jump to if the index has a value outside the 20829 bounds. 20830 20831 The table is a `addr_vec' or `addr_diff_vec' inside of a 20832 `jump_insn'. The number of elements in the table is one plus the 20833 difference between the upper bound and the lower bound. 20834 20835 `tablejump' 20836 Instruction to jump to a variable address. This is a low-level 20837 capability which can be used to implement a dispatch table when 20838 there is no `casesi' pattern. 20839 20840 This pattern requires two operands: the address or offset, and a 20841 label which should immediately precede the jump table. If the 20842 macro `CASE_VECTOR_PC_RELATIVE' evaluates to a nonzero value then 20843 the first operand is an offset which counts from the address of 20844 the table; otherwise, it is an absolute address to jump to. In 20845 either case, the first operand has mode `Pmode'. 20846 20847 The `tablejump' insn is always the last insn before the jump table 20848 it uses. Its assembler code normally has no need to use the 20849 second operand, but you should incorporate it in the RTL pattern so 20850 that the jump optimizer will not delete the table as unreachable 20851 code. 20852 20853 `decrement_and_branch_until_zero' 20854 Conditional branch instruction that decrements a register and 20855 jumps if the register is nonzero. Operand 0 is the register to 20856 decrement and test; operand 1 is the label to jump to if the 20857 register is nonzero. *Note Looping Patterns::. 20858 20859 This optional instruction pattern is only used by the combiner, 20860 typically for loops reversed by the loop optimizer when strength 20861 reduction is enabled. 20862 20863 `doloop_end' 20864 Conditional branch instruction that decrements a register and 20865 jumps if the register is nonzero. This instruction takes five 20866 operands: Operand 0 is the register to decrement and test; operand 20867 1 is the number of loop iterations as a `const_int' or 20868 `const0_rtx' if this cannot be determined until run-time; operand 20869 2 is the actual or estimated maximum number of iterations as a 20870 `const_int'; operand 3 is the number of enclosed loops as a 20871 `const_int' (an innermost loop has a value of 1); operand 4 is the 20872 label to jump to if the register is nonzero. *Note Looping 20873 Patterns::. 20874 20875 This optional instruction pattern should be defined for machines 20876 with low-overhead looping instructions as the loop optimizer will 20877 try to modify suitable loops to utilize it. If nested 20878 low-overhead looping is not supported, use a `define_expand' 20879 (*note Expander Definitions::) and make the pattern fail if 20880 operand 3 is not `const1_rtx'. Similarly, if the actual or 20881 estimated maximum number of iterations is too large for this 20882 instruction, make it fail. 20883 20884 `doloop_begin' 20885 Companion instruction to `doloop_end' required for machines that 20886 need to perform some initialization, such as loading special 20887 registers used by a low-overhead looping instruction. If 20888 initialization insns do not always need to be emitted, use a 20889 `define_expand' (*note Expander Definitions::) and make it fail. 20890 20891 `canonicalize_funcptr_for_compare' 20892 Canonicalize the function pointer in operand 1 and store the result 20893 into operand 0. 20894 20895 Operand 0 is always a `reg' and has mode `Pmode'; operand 1 may be 20896 a `reg', `mem', `symbol_ref', `const_int', etc and also has mode 20897 `Pmode'. 20898 20899 Canonicalization of a function pointer usually involves computing 20900 the address of the function which would be called if the function 20901 pointer were used in an indirect call. 20902 20903 Only define this pattern if function pointers on the target machine 20904 can have different values but still call the same function when 20905 used in an indirect call. 20906 20907 `save_stack_block' 20908 `save_stack_function' 20909 `save_stack_nonlocal' 20910 `restore_stack_block' 20911 `restore_stack_function' 20912 `restore_stack_nonlocal' 20913 Most machines save and restore the stack pointer by copying it to 20914 or from an object of mode `Pmode'. Do not define these patterns on 20915 such machines. 20916 20917 Some machines require special handling for stack pointer saves and 20918 restores. On those machines, define the patterns corresponding to 20919 the non-standard cases by using a `define_expand' (*note Expander 20920 Definitions::) that produces the required insns. The three types 20921 of saves and restores are: 20922 20923 1. `save_stack_block' saves the stack pointer at the start of a 20924 block that allocates a variable-sized object, and 20925 `restore_stack_block' restores the stack pointer when the 20926 block is exited. 20927 20928 2. `save_stack_function' and `restore_stack_function' do a 20929 similar job for the outermost block of a function and are 20930 used when the function allocates variable-sized objects or 20931 calls `alloca'. Only the epilogue uses the restored stack 20932 pointer, allowing a simpler save or restore sequence on some 20933 machines. 20934 20935 3. `save_stack_nonlocal' is used in functions that contain labels 20936 branched to by nested functions. It saves the stack pointer 20937 in such a way that the inner function can use 20938 `restore_stack_nonlocal' to restore the stack pointer. The 20939 compiler generates code to restore the frame and argument 20940 pointer registers, but some machines require saving and 20941 restoring additional data such as register window information 20942 or stack backchains. Place insns in these patterns to save 20943 and restore any such required data. 20944 20945 When saving the stack pointer, operand 0 is the save area and 20946 operand 1 is the stack pointer. The mode used to allocate the 20947 save area defaults to `Pmode' but you can override that choice by 20948 defining the `STACK_SAVEAREA_MODE' macro (*note Storage Layout::). 20949 You must specify an integral mode, or `VOIDmode' if no save area 20950 is needed for a particular type of save (either because no save is 20951 needed or because a machine-specific save area can be used). 20952 Operand 0 is the stack pointer and operand 1 is the save area for 20953 restore operations. If `save_stack_block' is defined, operand 0 20954 must not be `VOIDmode' since these saves can be arbitrarily nested. 20955 20956 A save area is a `mem' that is at a constant offset from 20957 `virtual_stack_vars_rtx' when the stack pointer is saved for use by 20958 nonlocal gotos and a `reg' in the other two cases. 20959 20960 `allocate_stack' 20961 Subtract (or add if `STACK_GROWS_DOWNWARD' is undefined) operand 1 20962 from the stack pointer to create space for dynamically allocated 20963 data. 20964 20965 Store the resultant pointer to this space into operand 0. If you 20966 are allocating space from the main stack, do this by emitting a 20967 move insn to copy `virtual_stack_dynamic_rtx' to operand 0. If 20968 you are allocating the space elsewhere, generate code to copy the 20969 location of the space to operand 0. In the latter case, you must 20970 ensure this space gets freed when the corresponding space on the 20971 main stack is free. 20972 20973 Do not define this pattern if all that must be done is the 20974 subtraction. Some machines require other operations such as stack 20975 probes or maintaining the back chain. Define this pattern to emit 20976 those operations in addition to updating the stack pointer. 20977 20978 `check_stack' 20979 If stack checking cannot be done on your system by probing the 20980 stack with a load or store instruction (*note Stack Checking::), 20981 define this pattern to perform the needed check and signaling an 20982 error if the stack has overflowed. The single operand is the 20983 location in the stack furthest from the current stack pointer that 20984 you need to validate. Normally, on machines where this pattern is 20985 needed, you would obtain the stack limit from a global or 20986 thread-specific variable or register. 20987 20988 `nonlocal_goto' 20989 Emit code to generate a non-local goto, e.g., a jump from one 20990 function to a label in an outer function. This pattern has four 20991 arguments, each representing a value to be used in the jump. The 20992 first argument is to be loaded into the frame pointer, the second 20993 is the address to branch to (code to dispatch to the actual label), 20994 the third is the address of a location where the stack is saved, 20995 and the last is the address of the label, to be placed in the 20996 location for the incoming static chain. 20997 20998 On most machines you need not define this pattern, since GCC will 20999 already generate the correct code, which is to load the frame 21000 pointer and static chain, restore the stack (using the 21001 `restore_stack_nonlocal' pattern, if defined), and jump indirectly 21002 to the dispatcher. You need only define this pattern if this code 21003 will not work on your machine. 21004 21005 `nonlocal_goto_receiver' 21006 This pattern, if defined, contains code needed at the target of a 21007 nonlocal goto after the code already generated by GCC. You will 21008 not normally need to define this pattern. A typical reason why 21009 you might need this pattern is if some value, such as a pointer to 21010 a global table, must be restored when the frame pointer is 21011 restored. Note that a nonlocal goto only occurs within a 21012 unit-of-translation, so a global table pointer that is shared by 21013 all functions of a given module need not be restored. There are 21014 no arguments. 21015 21016 `exception_receiver' 21017 This pattern, if defined, contains code needed at the site of an 21018 exception handler that isn't needed at the site of a nonlocal 21019 goto. You will not normally need to define this pattern. A 21020 typical reason why you might need this pattern is if some value, 21021 such as a pointer to a global table, must be restored after 21022 control flow is branched to the handler of an exception. There 21023 are no arguments. 21024 21025 `builtin_setjmp_setup' 21026 This pattern, if defined, contains additional code needed to 21027 initialize the `jmp_buf'. You will not normally need to define 21028 this pattern. A typical reason why you might need this pattern is 21029 if some value, such as a pointer to a global table, must be 21030 restored. Though it is preferred that the pointer value be 21031 recalculated if possible (given the address of a label for 21032 instance). The single argument is a pointer to the `jmp_buf'. 21033 Note that the buffer is five words long and that the first three 21034 are normally used by the generic mechanism. 21035 21036 `builtin_setjmp_receiver' 21037 This pattern, if defined, contains code needed at the site of an 21038 built-in setjmp that isn't needed at the site of a nonlocal goto. 21039 You will not normally need to define this pattern. A typical 21040 reason why you might need this pattern is if some value, such as a 21041 pointer to a global table, must be restored. It takes one 21042 argument, which is the label to which builtin_longjmp transfered 21043 control; this pattern may be emitted at a small offset from that 21044 label. 21045 21046 `builtin_longjmp' 21047 This pattern, if defined, performs the entire action of the 21048 longjmp. You will not normally need to define this pattern unless 21049 you also define `builtin_setjmp_setup'. The single argument is a 21050 pointer to the `jmp_buf'. 21051 21052 `eh_return' 21053 This pattern, if defined, affects the way `__builtin_eh_return', 21054 and thence the call frame exception handling library routines, are 21055 built. It is intended to handle non-trivial actions needed along 21056 the abnormal return path. 21057 21058 The address of the exception handler to which the function should 21059 return is passed as operand to this pattern. It will normally 21060 need to copied by the pattern to some special register or memory 21061 location. If the pattern needs to determine the location of the 21062 target call frame in order to do so, it may use 21063 `EH_RETURN_STACKADJ_RTX', if defined; it will have already been 21064 assigned. 21065 21066 If this pattern is not defined, the default action will be to 21067 simply copy the return address to `EH_RETURN_HANDLER_RTX'. Either 21068 that macro or this pattern needs to be defined if call frame 21069 exception handling is to be used. 21070 21071 `prologue' 21072 This pattern, if defined, emits RTL for entry to a function. The 21073 function entry is responsible for setting up the stack frame, 21074 initializing the frame pointer register, saving callee saved 21075 registers, etc. 21076 21077 Using a prologue pattern is generally preferred over defining 21078 `TARGET_ASM_FUNCTION_PROLOGUE' to emit assembly code for the 21079 prologue. 21080 21081 The `prologue' pattern is particularly useful for targets which 21082 perform instruction scheduling. 21083 21084 `epilogue' 21085 This pattern emits RTL for exit from a function. The function 21086 exit is responsible for deallocating the stack frame, restoring 21087 callee saved registers and emitting the return instruction. 21088 21089 Using an epilogue pattern is generally preferred over defining 21090 `TARGET_ASM_FUNCTION_EPILOGUE' to emit assembly code for the 21091 epilogue. 21092 21093 The `epilogue' pattern is particularly useful for targets which 21094 perform instruction scheduling or which have delay slots for their 21095 return instruction. 21096 21097 `sibcall_epilogue' 21098 This pattern, if defined, emits RTL for exit from a function 21099 without the final branch back to the calling function. This 21100 pattern will be emitted before any sibling call (aka tail call) 21101 sites. 21102 21103 The `sibcall_epilogue' pattern must not clobber any arguments used 21104 for parameter passing or any stack slots for arguments passed to 21105 the current function. 21106 21107 `trap' 21108 This pattern, if defined, signals an error, typically by causing 21109 some kind of signal to be raised. Among other places, it is used 21110 by the Java front end to signal `invalid array index' exceptions. 21111 21112 `conditional_trap' 21113 Conditional trap instruction. Operand 0 is a piece of RTL which 21114 performs a comparison. Operand 1 is the trap code, an integer. 21115 21116 A typical `conditional_trap' pattern looks like 21117 21118 (define_insn "conditional_trap" 21119 [(trap_if (match_operator 0 "trap_operator" 21120 [(cc0) (const_int 0)]) 21121 (match_operand 1 "const_int_operand" "i"))] 21122 "" 21123 "...") 21124 21125 `prefetch' 21126 This pattern, if defined, emits code for a non-faulting data 21127 prefetch instruction. Operand 0 is the address of the memory to 21128 prefetch. Operand 1 is a constant 1 if the prefetch is preparing 21129 for a write to the memory address, or a constant 0 otherwise. 21130 Operand 2 is the expected degree of temporal locality of the data 21131 and is a value between 0 and 3, inclusive; 0 means that the data 21132 has no temporal locality, so it need not be left in the cache 21133 after the access; 3 means that the data has a high degree of 21134 temporal locality and should be left in all levels of cache 21135 possible; 1 and 2 mean, respectively, a low or moderate degree of 21136 temporal locality. 21137 21138 Targets that do not support write prefetches or locality hints can 21139 ignore the values of operands 1 and 2. 21140 21141 `blockage' 21142 This pattern defines a pseudo insn that prevents the instruction 21143 scheduler from moving instructions across the boundary defined by 21144 the blockage insn. Normally an UNSPEC_VOLATILE pattern. 21145 21146 `memory_barrier' 21147 If the target memory model is not fully synchronous, then this 21148 pattern should be defined to an instruction that orders both loads 21149 and stores before the instruction with respect to loads and stores 21150 after the instruction. This pattern has no operands. 21151 21152 `sync_compare_and_swapMODE' 21153 This pattern, if defined, emits code for an atomic compare-and-swap 21154 operation. Operand 1 is the memory on which the atomic operation 21155 is performed. Operand 2 is the "old" value to be compared against 21156 the current contents of the memory location. Operand 3 is the 21157 "new" value to store in the memory if the compare succeeds. 21158 Operand 0 is the result of the operation; it should contain the 21159 contents of the memory before the operation. If the compare 21160 succeeds, this should obviously be a copy of operand 2. 21161 21162 This pattern must show that both operand 0 and operand 1 are 21163 modified. 21164 21165 This pattern must issue any memory barrier instructions such that 21166 all memory operations before the atomic operation occur before the 21167 atomic operation and all memory operations after the atomic 21168 operation occur after the atomic operation. 21169 21170 `sync_compare_and_swap_ccMODE' 21171 This pattern is just like `sync_compare_and_swapMODE', except it 21172 should act as if compare part of the compare-and-swap were issued 21173 via `cmpM'. This comparison will only be used with `EQ' and `NE' 21174 branches and `setcc' operations. 21175 21176 Some targets do expose the success or failure of the 21177 compare-and-swap operation via the status flags. Ideally we 21178 wouldn't need a separate named pattern in order to take advantage 21179 of this, but the combine pass does not handle patterns with 21180 multiple sets, which is required by definition for 21181 `sync_compare_and_swapMODE'. 21182 21183 `sync_addMODE', `sync_subMODE' 21184 `sync_iorMODE', `sync_andMODE' 21185 `sync_xorMODE', `sync_nandMODE' 21186 These patterns emit code for an atomic operation on memory. 21187 Operand 0 is the memory on which the atomic operation is performed. 21188 Operand 1 is the second operand to the binary operator. 21189 21190 The "nand" operation is `~op0 & op1'. 21191 21192 This pattern must issue any memory barrier instructions such that 21193 all memory operations before the atomic operation occur before the 21194 atomic operation and all memory operations after the atomic 21195 operation occur after the atomic operation. 21196 21197 If these patterns are not defined, the operation will be 21198 constructed from a compare-and-swap operation, if defined. 21199 21200 `sync_old_addMODE', `sync_old_subMODE' 21201 `sync_old_iorMODE', `sync_old_andMODE' 21202 `sync_old_xorMODE', `sync_old_nandMODE' 21203 These patterns are emit code for an atomic operation on memory, 21204 and return the value that the memory contained before the 21205 operation. Operand 0 is the result value, operand 1 is the memory 21206 on which the atomic operation is performed, and operand 2 is the 21207 second operand to the binary operator. 21208 21209 This pattern must issue any memory barrier instructions such that 21210 all memory operations before the atomic operation occur before the 21211 atomic operation and all memory operations after the atomic 21212 operation occur after the atomic operation. 21213 21214 If these patterns are not defined, the operation will be 21215 constructed from a compare-and-swap operation, if defined. 21216 21217 `sync_new_addMODE', `sync_new_subMODE' 21218 `sync_new_iorMODE', `sync_new_andMODE' 21219 `sync_new_xorMODE', `sync_new_nandMODE' 21220 These patterns are like their `sync_old_OP' counterparts, except 21221 that they return the value that exists in the memory location 21222 after the operation, rather than before the operation. 21223 21224 `sync_lock_test_and_setMODE' 21225 This pattern takes two forms, based on the capabilities of the 21226 target. In either case, operand 0 is the result of the operand, 21227 operand 1 is the memory on which the atomic operation is 21228 performed, and operand 2 is the value to set in the lock. 21229 21230 In the ideal case, this operation is an atomic exchange operation, 21231 in which the previous value in memory operand is copied into the 21232 result operand, and the value operand is stored in the memory 21233 operand. 21234 21235 For less capable targets, any value operand that is not the 21236 constant 1 should be rejected with `FAIL'. In this case the 21237 target may use an atomic test-and-set bit operation. The result 21238 operand should contain 1 if the bit was previously set and 0 if 21239 the bit was previously clear. The true contents of the memory 21240 operand are implementation defined. 21241 21242 This pattern must issue any memory barrier instructions such that 21243 the pattern as a whole acts as an acquire barrier, that is all 21244 memory operations after the pattern do not occur until the lock is 21245 acquired. 21246 21247 If this pattern is not defined, the operation will be constructed 21248 from a compare-and-swap operation, if defined. 21249 21250 `sync_lock_releaseMODE' 21251 This pattern, if defined, releases a lock set by 21252 `sync_lock_test_and_setMODE'. Operand 0 is the memory that 21253 contains the lock; operand 1 is the value to store in the lock. 21254 21255 If the target doesn't implement full semantics for 21256 `sync_lock_test_and_setMODE', any value operand which is not the 21257 constant 0 should be rejected with `FAIL', and the true contents 21258 of the memory operand are implementation defined. 21259 21260 This pattern must issue any memory barrier instructions such that 21261 the pattern as a whole acts as a release barrier, that is the lock 21262 is released only after all previous memory operations have 21263 completed. 21264 21265 If this pattern is not defined, then a `memory_barrier' pattern 21266 will be emitted, followed by a store of the value to the memory 21267 operand. 21268 21269 `stack_protect_set' 21270 This pattern, if defined, moves a `Pmode' value from the memory in 21271 operand 1 to the memory in operand 0 without leaving the value in 21272 a register afterward. This is to avoid leaking the value some 21273 place that an attacker might use to rewrite the stack guard slot 21274 after having clobbered it. 21275 21276 If this pattern is not defined, then a plain move pattern is 21277 generated. 21278 21279 `stack_protect_test' 21280 This pattern, if defined, compares a `Pmode' value from the memory 21281 in operand 1 with the memory in operand 0 without leaving the 21282 value in a register afterward and branches to operand 2 if the 21283 values weren't equal. 21284 21285 If this pattern is not defined, then a plain compare pattern and 21286 conditional branch pattern is used. 21287 21288 `clear_cache' 21289 This pattern, if defined, flushes the instruction cache for a 21290 region of memory. The region is bounded to by the Pmode pointers 21291 in operand 0 inclusive and operand 1 exclusive. 21292 21293 If this pattern is not defined, a call to the library function 21294 `__clear_cache' is used. 21295 21296 21297 21298 File: gccint.info, Node: Pattern Ordering, Next: Dependent Patterns, Prev: Standard Names, Up: Machine Desc 21299 21300 16.10 When the Order of Patterns Matters 21301 ======================================== 21302 21303 Sometimes an insn can match more than one instruction pattern. Then the 21304 pattern that appears first in the machine description is the one used. 21305 Therefore, more specific patterns (patterns that will match fewer 21306 things) and faster instructions (those that will produce better code 21307 when they do match) should usually go first in the description. 21308 21309 In some cases the effect of ordering the patterns can be used to hide 21310 a pattern when it is not valid. For example, the 68000 has an 21311 instruction for converting a fullword to floating point and another for 21312 converting a byte to floating point. An instruction converting an 21313 integer to floating point could match either one. We put the pattern 21314 to convert the fullword first to make sure that one will be used rather 21315 than the other. (Otherwise a large integer might be generated as a 21316 single-byte immediate quantity, which would not work.) Instead of 21317 using this pattern ordering it would be possible to make the pattern 21318 for convert-a-byte smart enough to deal properly with any constant 21319 value. 21320 21321 21322 File: gccint.info, Node: Dependent Patterns, Next: Jump Patterns, Prev: Pattern Ordering, Up: Machine Desc 21323 21324 16.11 Interdependence of Patterns 21325 ================================= 21326 21327 Every machine description must have a named pattern for each of the 21328 conditional branch names `bCOND'. The recognition template must always 21329 have the form 21330 21331 (set (pc) 21332 (if_then_else (COND (cc0) (const_int 0)) 21333 (label_ref (match_operand 0 "" "")) 21334 (pc))) 21335 21336 In addition, every machine description must have an anonymous pattern 21337 for each of the possible reverse-conditional branches. Their templates 21338 look like 21339 21340 (set (pc) 21341 (if_then_else (COND (cc0) (const_int 0)) 21342 (pc) 21343 (label_ref (match_operand 0 "" "")))) 21344 21345 They are necessary because jump optimization can turn direct-conditional 21346 branches into reverse-conditional branches. 21347 21348 It is often convenient to use the `match_operator' construct to reduce 21349 the number of patterns that must be specified for branches. For 21350 example, 21351 21352 (define_insn "" 21353 [(set (pc) 21354 (if_then_else (match_operator 0 "comparison_operator" 21355 [(cc0) (const_int 0)]) 21356 (pc) 21357 (label_ref (match_operand 1 "" ""))))] 21358 "CONDITION" 21359 "...") 21360 21361 In some cases machines support instructions identical except for the 21362 machine mode of one or more operands. For example, there may be 21363 "sign-extend halfword" and "sign-extend byte" instructions whose 21364 patterns are 21365 21366 (set (match_operand:SI 0 ...) 21367 (extend:SI (match_operand:HI 1 ...))) 21368 21369 (set (match_operand:SI 0 ...) 21370 (extend:SI (match_operand:QI 1 ...))) 21371 21372 Constant integers do not specify a machine mode, so an instruction to 21373 extend a constant value could match either pattern. The pattern it 21374 actually will match is the one that appears first in the file. For 21375 correct results, this must be the one for the widest possible mode 21376 (`HImode', here). If the pattern matches the `QImode' instruction, the 21377 results will be incorrect if the constant value does not actually fit 21378 that mode. 21379 21380 Such instructions to extend constants are rarely generated because 21381 they are optimized away, but they do occasionally happen in nonoptimized 21382 compilations. 21383 21384 If a constraint in a pattern allows a constant, the reload pass may 21385 replace a register with a constant permitted by the constraint in some 21386 cases. Similarly for memory references. Because of this substitution, 21387 you should not provide separate patterns for increment and decrement 21388 instructions. Instead, they should be generated from the same pattern 21389 that supports register-register add insns by examining the operands and 21390 generating the appropriate machine instruction. 21391 21392 21393 File: gccint.info, Node: Jump Patterns, Next: Looping Patterns, Prev: Dependent Patterns, Up: Machine Desc 21394 21395 16.12 Defining Jump Instruction Patterns 21396 ======================================== 21397 21398 For most machines, GCC assumes that the machine has a condition code. 21399 A comparison insn sets the condition code, recording the results of both 21400 signed and unsigned comparison of the given operands. A separate branch 21401 insn tests the condition code and branches or not according its value. 21402 The branch insns come in distinct signed and unsigned flavors. Many 21403 common machines, such as the VAX, the 68000 and the 32000, work this 21404 way. 21405 21406 Some machines have distinct signed and unsigned compare instructions, 21407 and only one set of conditional branch instructions. The easiest way 21408 to handle these machines is to treat them just like the others until 21409 the final stage where assembly code is written. At this time, when 21410 outputting code for the compare instruction, peek ahead at the 21411 following branch using `next_cc0_user (insn)'. (The variable `insn' 21412 refers to the insn being output, in the output-writing code in an 21413 instruction pattern.) If the RTL says that is an unsigned branch, 21414 output an unsigned compare; otherwise output a signed compare. When 21415 the branch itself is output, you can treat signed and unsigned branches 21416 identically. 21417 21418 The reason you can do this is that GCC always generates a pair of 21419 consecutive RTL insns, possibly separated by `note' insns, one to set 21420 the condition code and one to test it, and keeps the pair inviolate 21421 until the end. 21422 21423 To go with this technique, you must define the machine-description 21424 macro `NOTICE_UPDATE_CC' to do `CC_STATUS_INIT'; in other words, no 21425 compare instruction is superfluous. 21426 21427 Some machines have compare-and-branch instructions and no condition 21428 code. A similar technique works for them. When it is time to "output" 21429 a compare instruction, record its operands in two static variables. 21430 When outputting the branch-on-condition-code instruction that follows, 21431 actually output a compare-and-branch instruction that uses the 21432 remembered operands. 21433 21434 It also works to define patterns for compare-and-branch instructions. 21435 In optimizing compilation, the pair of compare and branch instructions 21436 will be combined according to these patterns. But this does not happen 21437 if optimization is not requested. So you must use one of the solutions 21438 above in addition to any special patterns you define. 21439 21440 In many RISC machines, most instructions do not affect the condition 21441 code and there may not even be a separate condition code register. On 21442 these machines, the restriction that the definition and use of the 21443 condition code be adjacent insns is not necessary and can prevent 21444 important optimizations. For example, on the IBM RS/6000, there is a 21445 delay for taken branches unless the condition code register is set three 21446 instructions earlier than the conditional branch. The instruction 21447 scheduler cannot perform this optimization if it is not permitted to 21448 separate the definition and use of the condition code register. 21449 21450 On these machines, do not use `(cc0)', but instead use a register to 21451 represent the condition code. If there is a specific condition code 21452 register in the machine, use a hard register. If the condition code or 21453 comparison result can be placed in any general register, or if there are 21454 multiple condition registers, use a pseudo register. 21455 21456 On some machines, the type of branch instruction generated may depend 21457 on the way the condition code was produced; for example, on the 68k and 21458 SPARC, setting the condition code directly from an add or subtract 21459 instruction does not clear the overflow bit the way that a test 21460 instruction does, so a different branch instruction must be used for 21461 some conditional branches. For machines that use `(cc0)', the set and 21462 use of the condition code must be adjacent (separated only by `note' 21463 insns) allowing flags in `cc_status' to be used. (*Note Condition 21464 Code::.) Also, the comparison and branch insns can be located from 21465 each other by using the functions `prev_cc0_setter' and `next_cc0_user'. 21466 21467 However, this is not true on machines that do not use `(cc0)'. On 21468 those machines, no assumptions can be made about the adjacency of the 21469 compare and branch insns and the above methods cannot be used. Instead, 21470 we use the machine mode of the condition code register to record 21471 different formats of the condition code register. 21472 21473 Registers used to store the condition code value should have a mode 21474 that is in class `MODE_CC'. Normally, it will be `CCmode'. If 21475 additional modes are required (as for the add example mentioned above in 21476 the SPARC), define them in `MACHINE-modes.def' (*note Condition 21477 Code::). Also define `SELECT_CC_MODE' to choose a mode given an 21478 operand of a compare. 21479 21480 If it is known during RTL generation that a different mode will be 21481 required (for example, if the machine has separate compare instructions 21482 for signed and unsigned quantities, like most IBM processors), they can 21483 be specified at that time. 21484 21485 If the cases that require different modes would be made by instruction 21486 combination, the macro `SELECT_CC_MODE' determines which machine mode 21487 should be used for the comparison result. The patterns should be 21488 written using that mode. To support the case of the add on the SPARC 21489 discussed above, we have the pattern 21490 21491 (define_insn "" 21492 [(set (reg:CC_NOOV 0) 21493 (compare:CC_NOOV 21494 (plus:SI (match_operand:SI 0 "register_operand" "%r") 21495 (match_operand:SI 1 "arith_operand" "rI")) 21496 (const_int 0)))] 21497 "" 21498 "...") 21499 21500 The `SELECT_CC_MODE' macro on the SPARC returns `CC_NOOVmode' for 21501 comparisons whose argument is a `plus'. 21502 21503 21504 File: gccint.info, Node: Looping Patterns, Next: Insn Canonicalizations, Prev: Jump Patterns, Up: Machine Desc 21505 21506 16.13 Defining Looping Instruction Patterns 21507 =========================================== 21508 21509 Some machines have special jump instructions that can be utilized to 21510 make loops more efficient. A common example is the 68000 `dbra' 21511 instruction which performs a decrement of a register and a branch if the 21512 result was greater than zero. Other machines, in particular digital 21513 signal processors (DSPs), have special block repeat instructions to 21514 provide low-overhead loop support. For example, the TI TMS320C3x/C4x 21515 DSPs have a block repeat instruction that loads special registers to 21516 mark the top and end of a loop and to count the number of loop 21517 iterations. This avoids the need for fetching and executing a 21518 `dbra'-like instruction and avoids pipeline stalls associated with the 21519 jump. 21520 21521 GCC has three special named patterns to support low overhead looping. 21522 They are `decrement_and_branch_until_zero', `doloop_begin', and 21523 `doloop_end'. The first pattern, `decrement_and_branch_until_zero', is 21524 not emitted during RTL generation but may be emitted during the 21525 instruction combination phase. This requires the assistance of the 21526 loop optimizer, using information collected during strength reduction, 21527 to reverse a loop to count down to zero. Some targets also require the 21528 loop optimizer to add a `REG_NONNEG' note to indicate that the 21529 iteration count is always positive. This is needed if the target 21530 performs a signed loop termination test. For example, the 68000 uses a 21531 pattern similar to the following for its `dbra' instruction: 21532 21533 (define_insn "decrement_and_branch_until_zero" 21534 [(set (pc) 21535 (if_then_else 21536 (ge (plus:SI (match_operand:SI 0 "general_operand" "+d*am") 21537 (const_int -1)) 21538 (const_int 0)) 21539 (label_ref (match_operand 1 "" "")) 21540 (pc))) 21541 (set (match_dup 0) 21542 (plus:SI (match_dup 0) 21543 (const_int -1)))] 21544 "find_reg_note (insn, REG_NONNEG, 0)" 21545 "...") 21546 21547 Note that since the insn is both a jump insn and has an output, it must 21548 deal with its own reloads, hence the `m' constraints. Also note that 21549 since this insn is generated by the instruction combination phase 21550 combining two sequential insns together into an implicit parallel insn, 21551 the iteration counter needs to be biased by the same amount as the 21552 decrement operation, in this case -1. Note that the following similar 21553 pattern will not be matched by the combiner. 21554 21555 (define_insn "decrement_and_branch_until_zero" 21556 [(set (pc) 21557 (if_then_else 21558 (ge (match_operand:SI 0 "general_operand" "+d*am") 21559 (const_int 1)) 21560 (label_ref (match_operand 1 "" "")) 21561 (pc))) 21562 (set (match_dup 0) 21563 (plus:SI (match_dup 0) 21564 (const_int -1)))] 21565 "find_reg_note (insn, REG_NONNEG, 0)" 21566 "...") 21567 21568 The other two special looping patterns, `doloop_begin' and 21569 `doloop_end', are emitted by the loop optimizer for certain 21570 well-behaved loops with a finite number of loop iterations using 21571 information collected during strength reduction. 21572 21573 The `doloop_end' pattern describes the actual looping instruction (or 21574 the implicit looping operation) and the `doloop_begin' pattern is an 21575 optional companion pattern that can be used for initialization needed 21576 for some low-overhead looping instructions. 21577 21578 Note that some machines require the actual looping instruction to be 21579 emitted at the top of the loop (e.g., the TMS320C3x/C4x DSPs). Emitting 21580 the true RTL for a looping instruction at the top of the loop can cause 21581 problems with flow analysis. So instead, a dummy `doloop' insn is 21582 emitted at the end of the loop. The machine dependent reorg pass checks 21583 for the presence of this `doloop' insn and then searches back to the 21584 top of the loop, where it inserts the true looping insn (provided there 21585 are no instructions in the loop which would cause problems). Any 21586 additional labels can be emitted at this point. In addition, if the 21587 desired special iteration counter register was not allocated, this 21588 machine dependent reorg pass could emit a traditional compare and jump 21589 instruction pair. 21590 21591 The essential difference between the `decrement_and_branch_until_zero' 21592 and the `doloop_end' patterns is that the loop optimizer allocates an 21593 additional pseudo register for the latter as an iteration counter. 21594 This pseudo register cannot be used within the loop (i.e., general 21595 induction variables cannot be derived from it), however, in many cases 21596 the loop induction variable may become redundant and removed by the 21597 flow pass. 21598 21599 21600 File: gccint.info, Node: Insn Canonicalizations, Next: Expander Definitions, Prev: Looping Patterns, Up: Machine Desc 21601 21602 16.14 Canonicalization of Instructions 21603 ====================================== 21604 21605 There are often cases where multiple RTL expressions could represent an 21606 operation performed by a single machine instruction. This situation is 21607 most commonly encountered with logical, branch, and multiply-accumulate 21608 instructions. In such cases, the compiler attempts to convert these 21609 multiple RTL expressions into a single canonical form to reduce the 21610 number of insn patterns required. 21611 21612 In addition to algebraic simplifications, following canonicalizations 21613 are performed: 21614 21615 * For commutative and comparison operators, a constant is always 21616 made the second operand. If a machine only supports a constant as 21617 the second operand, only patterns that match a constant in the 21618 second operand need be supplied. 21619 21620 * For associative operators, a sequence of operators will always 21621 chain to the left; for instance, only the left operand of an 21622 integer `plus' can itself be a `plus'. `and', `ior', `xor', 21623 `plus', `mult', `smin', `smax', `umin', and `umax' are associative 21624 when applied to integers, and sometimes to floating-point. 21625 21626 * For these operators, if only one operand is a `neg', `not', 21627 `mult', `plus', or `minus' expression, it will be the first 21628 operand. 21629 21630 * In combinations of `neg', `mult', `plus', and `minus', the `neg' 21631 operations (if any) will be moved inside the operations as far as 21632 possible. For instance, `(neg (mult A B))' is canonicalized as 21633 `(mult (neg A) B)', but `(plus (mult (neg A) B) C)' is 21634 canonicalized as `(minus A (mult B C))'. 21635 21636 * For the `compare' operator, a constant is always the second operand 21637 on machines where `cc0' is used (*note Jump Patterns::). On other 21638 machines, there are rare cases where the compiler might want to 21639 construct a `compare' with a constant as the first operand. 21640 However, these cases are not common enough for it to be worthwhile 21641 to provide a pattern matching a constant as the first operand 21642 unless the machine actually has such an instruction. 21643 21644 An operand of `neg', `not', `mult', `plus', or `minus' is made the 21645 first operand under the same conditions as above. 21646 21647 * `(ltu (plus A B) B)' is converted to `(ltu (plus A B) A)'. 21648 Likewise with `geu' instead of `ltu'. 21649 21650 * `(minus X (const_int N))' is converted to `(plus X (const_int 21651 -N))'. 21652 21653 * Within address computations (i.e., inside `mem'), a left shift is 21654 converted into the appropriate multiplication by a power of two. 21655 21656 * De Morgan's Law is used to move bitwise negation inside a bitwise 21657 logical-and or logical-or operation. If this results in only one 21658 operand being a `not' expression, it will be the first one. 21659 21660 A machine that has an instruction that performs a bitwise 21661 logical-and of one operand with the bitwise negation of the other 21662 should specify the pattern for that instruction as 21663 21664 (define_insn "" 21665 [(set (match_operand:M 0 ...) 21666 (and:M (not:M (match_operand:M 1 ...)) 21667 (match_operand:M 2 ...)))] 21668 "..." 21669 "...") 21670 21671 Similarly, a pattern for a "NAND" instruction should be written 21672 21673 (define_insn "" 21674 [(set (match_operand:M 0 ...) 21675 (ior:M (not:M (match_operand:M 1 ...)) 21676 (not:M (match_operand:M 2 ...))))] 21677 "..." 21678 "...") 21679 21680 In both cases, it is not necessary to include patterns for the many 21681 logically equivalent RTL expressions. 21682 21683 * The only possible RTL expressions involving both bitwise 21684 exclusive-or and bitwise negation are `(xor:M X Y)' and `(not:M 21685 (xor:M X Y))'. 21686 21687 * The sum of three items, one of which is a constant, will only 21688 appear in the form 21689 21690 (plus:M (plus:M X Y) CONSTANT) 21691 21692 * On machines that do not use `cc0', `(compare X (const_int 0))' 21693 will be converted to X. 21694 21695 * Equality comparisons of a group of bits (usually a single bit) 21696 with zero will be written using `zero_extract' rather than the 21697 equivalent `and' or `sign_extract' operations. 21698 21699 21700 Further canonicalization rules are defined in the function 21701 `commutative_operand_precedence' in `gcc/rtlanal.c'. 21702 21703 21704 File: gccint.info, Node: Expander Definitions, Next: Insn Splitting, Prev: Insn Canonicalizations, Up: Machine Desc 21705 21706 16.15 Defining RTL Sequences for Code Generation 21707 ================================================ 21708 21709 On some target machines, some standard pattern names for RTL generation 21710 cannot be handled with single insn, but a sequence of RTL insns can 21711 represent them. For these target machines, you can write a 21712 `define_expand' to specify how to generate the sequence of RTL. 21713 21714 A `define_expand' is an RTL expression that looks almost like a 21715 `define_insn'; but, unlike the latter, a `define_expand' is used only 21716 for RTL generation and it can produce more than one RTL insn. 21717 21718 A `define_expand' RTX has four operands: 21719 21720 * The name. Each `define_expand' must have a name, since the only 21721 use for it is to refer to it by name. 21722 21723 * The RTL template. This is a vector of RTL expressions representing 21724 a sequence of separate instructions. Unlike `define_insn', there 21725 is no implicit surrounding `PARALLEL'. 21726 21727 * The condition, a string containing a C expression. This 21728 expression is used to express how the availability of this pattern 21729 depends on subclasses of target machine, selected by command-line 21730 options when GCC is run. This is just like the condition of a 21731 `define_insn' that has a standard name. Therefore, the condition 21732 (if present) may not depend on the data in the insn being matched, 21733 but only the target-machine-type flags. The compiler needs to 21734 test these conditions during initialization in order to learn 21735 exactly which named instructions are available in a particular run. 21736 21737 * The preparation statements, a string containing zero or more C 21738 statements which are to be executed before RTL code is generated 21739 from the RTL template. 21740 21741 Usually these statements prepare temporary registers for use as 21742 internal operands in the RTL template, but they can also generate 21743 RTL insns directly by calling routines such as `emit_insn', etc. 21744 Any such insns precede the ones that come from the RTL template. 21745 21746 Every RTL insn emitted by a `define_expand' must match some 21747 `define_insn' in the machine description. Otherwise, the compiler will 21748 crash when trying to generate code for the insn or trying to optimize 21749 it. 21750 21751 The RTL template, in addition to controlling generation of RTL insns, 21752 also describes the operands that need to be specified when this pattern 21753 is used. In particular, it gives a predicate for each operand. 21754 21755 A true operand, which needs to be specified in order to generate RTL 21756 from the pattern, should be described with a `match_operand' in its 21757 first occurrence in the RTL template. This enters information on the 21758 operand's predicate into the tables that record such things. GCC uses 21759 the information to preload the operand into a register if that is 21760 required for valid RTL code. If the operand is referred to more than 21761 once, subsequent references should use `match_dup'. 21762 21763 The RTL template may also refer to internal "operands" which are 21764 temporary registers or labels used only within the sequence made by the 21765 `define_expand'. Internal operands are substituted into the RTL 21766 template with `match_dup', never with `match_operand'. The values of 21767 the internal operands are not passed in as arguments by the compiler 21768 when it requests use of this pattern. Instead, they are computed 21769 within the pattern, in the preparation statements. These statements 21770 compute the values and store them into the appropriate elements of 21771 `operands' so that `match_dup' can find them. 21772 21773 There are two special macros defined for use in the preparation 21774 statements: `DONE' and `FAIL'. Use them with a following semicolon, as 21775 a statement. 21776 21777 `DONE' 21778 Use the `DONE' macro to end RTL generation for the pattern. The 21779 only RTL insns resulting from the pattern on this occasion will be 21780 those already emitted by explicit calls to `emit_insn' within the 21781 preparation statements; the RTL template will not be generated. 21782 21783 `FAIL' 21784 Make the pattern fail on this occasion. When a pattern fails, it 21785 means that the pattern was not truly available. The calling 21786 routines in the compiler will try other strategies for code 21787 generation using other patterns. 21788 21789 Failure is currently supported only for binary (addition, 21790 multiplication, shifting, etc.) and bit-field (`extv', `extzv', 21791 and `insv') operations. 21792 21793 If the preparation falls through (invokes neither `DONE' nor `FAIL'), 21794 then the `define_expand' acts like a `define_insn' in that the RTL 21795 template is used to generate the insn. 21796 21797 The RTL template is not used for matching, only for generating the 21798 initial insn list. If the preparation statement always invokes `DONE' 21799 or `FAIL', the RTL template may be reduced to a simple list of 21800 operands, such as this example: 21801 21802 (define_expand "addsi3" 21803 [(match_operand:SI 0 "register_operand" "") 21804 (match_operand:SI 1 "register_operand" "") 21805 (match_operand:SI 2 "register_operand" "")] 21806 "" 21807 " 21808 { 21809 handle_add (operands[0], operands[1], operands[2]); 21810 DONE; 21811 }") 21812 21813 Here is an example, the definition of left-shift for the SPUR chip: 21814 21815 (define_expand "ashlsi3" 21816 [(set (match_operand:SI 0 "register_operand" "") 21817 (ashift:SI 21818 (match_operand:SI 1 "register_operand" "") 21819 (match_operand:SI 2 "nonmemory_operand" "")))] 21820 "" 21821 " 21822 21823 { 21824 if (GET_CODE (operands[2]) != CONST_INT 21825 || (unsigned) INTVAL (operands[2]) > 3) 21826 FAIL; 21827 }") 21828 21829 This example uses `define_expand' so that it can generate an RTL insn 21830 for shifting when the shift-count is in the supported range of 0 to 3 21831 but fail in other cases where machine insns aren't available. When it 21832 fails, the compiler tries another strategy using different patterns 21833 (such as, a library call). 21834 21835 If the compiler were able to handle nontrivial condition-strings in 21836 patterns with names, then it would be possible to use a `define_insn' 21837 in that case. Here is another case (zero-extension on the 68000) which 21838 makes more use of the power of `define_expand': 21839 21840 (define_expand "zero_extendhisi2" 21841 [(set (match_operand:SI 0 "general_operand" "") 21842 (const_int 0)) 21843 (set (strict_low_part 21844 (subreg:HI 21845 (match_dup 0) 21846 0)) 21847 (match_operand:HI 1 "general_operand" ""))] 21848 "" 21849 "operands[1] = make_safe_from (operands[1], operands[0]);") 21850 21851 Here two RTL insns are generated, one to clear the entire output operand 21852 and the other to copy the input operand into its low half. This 21853 sequence is incorrect if the input operand refers to [the old value of] 21854 the output operand, so the preparation statement makes sure this isn't 21855 so. The function `make_safe_from' copies the `operands[1]' into a 21856 temporary register if it refers to `operands[0]'. It does this by 21857 emitting another RTL insn. 21858 21859 Finally, a third example shows the use of an internal operand. 21860 Zero-extension on the SPUR chip is done by `and'-ing the result against 21861 a halfword mask. But this mask cannot be represented by a `const_int' 21862 because the constant value is too large to be legitimate on this 21863 machine. So it must be copied into a register with `force_reg' and 21864 then the register used in the `and'. 21865 21866 (define_expand "zero_extendhisi2" 21867 [(set (match_operand:SI 0 "register_operand" "") 21868 (and:SI (subreg:SI 21869 (match_operand:HI 1 "register_operand" "") 21870 0) 21871 (match_dup 2)))] 21872 "" 21873 "operands[2] 21874 = force_reg (SImode, GEN_INT (65535)); ") 21875 21876 _Note:_ If the `define_expand' is used to serve a standard binary or 21877 unary arithmetic operation or a bit-field operation, then the last insn 21878 it generates must not be a `code_label', `barrier' or `note'. It must 21879 be an `insn', `jump_insn' or `call_insn'. If you don't need a real insn 21880 at the end, emit an insn to copy the result of the operation into 21881 itself. Such an insn will generate no code, but it can avoid problems 21882 in the compiler. 21883 21884 21885 File: gccint.info, Node: Insn Splitting, Next: Including Patterns, Prev: Expander Definitions, Up: Machine Desc 21886 21887 16.16 Defining How to Split Instructions 21888 ======================================== 21889 21890 There are two cases where you should specify how to split a pattern 21891 into multiple insns. On machines that have instructions requiring 21892 delay slots (*note Delay Slots::) or that have instructions whose 21893 output is not available for multiple cycles (*note Processor pipeline 21894 description::), the compiler phases that optimize these cases need to 21895 be able to move insns into one-instruction delay slots. However, some 21896 insns may generate more than one machine instruction. These insns 21897 cannot be placed into a delay slot. 21898 21899 Often you can rewrite the single insn as a list of individual insns, 21900 each corresponding to one machine instruction. The disadvantage of 21901 doing so is that it will cause the compilation to be slower and require 21902 more space. If the resulting insns are too complex, it may also 21903 suppress some optimizations. The compiler splits the insn if there is a 21904 reason to believe that it might improve instruction or delay slot 21905 scheduling. 21906 21907 The insn combiner phase also splits putative insns. If three insns are 21908 merged into one insn with a complex expression that cannot be matched by 21909 some `define_insn' pattern, the combiner phase attempts to split the 21910 complex pattern into two insns that are recognized. Usually it can 21911 break the complex pattern into two patterns by splitting out some 21912 subexpression. However, in some other cases, such as performing an 21913 addition of a large constant in two insns on a RISC machine, the way to 21914 split the addition into two insns is machine-dependent. 21915 21916 The `define_split' definition tells the compiler how to split a 21917 complex insn into several simpler insns. It looks like this: 21918 21919 (define_split 21920 [INSN-PATTERN] 21921 "CONDITION" 21922 [NEW-INSN-PATTERN-1 21923 NEW-INSN-PATTERN-2 21924 ...] 21925 "PREPARATION-STATEMENTS") 21926 21927 INSN-PATTERN is a pattern that needs to be split and CONDITION is the 21928 final condition to be tested, as in a `define_insn'. When an insn 21929 matching INSN-PATTERN and satisfying CONDITION is found, it is replaced 21930 in the insn list with the insns given by NEW-INSN-PATTERN-1, 21931 NEW-INSN-PATTERN-2, etc. 21932 21933 The PREPARATION-STATEMENTS are similar to those statements that are 21934 specified for `define_expand' (*note Expander Definitions::) and are 21935 executed before the new RTL is generated to prepare for the generated 21936 code or emit some insns whose pattern is not fixed. Unlike those in 21937 `define_expand', however, these statements must not generate any new 21938 pseudo-registers. Once reload has completed, they also must not 21939 allocate any space in the stack frame. 21940 21941 Patterns are matched against INSN-PATTERN in two different 21942 circumstances. If an insn needs to be split for delay slot scheduling 21943 or insn scheduling, the insn is already known to be valid, which means 21944 that it must have been matched by some `define_insn' and, if 21945 `reload_completed' is nonzero, is known to satisfy the constraints of 21946 that `define_insn'. In that case, the new insn patterns must also be 21947 insns that are matched by some `define_insn' and, if `reload_completed' 21948 is nonzero, must also satisfy the constraints of those definitions. 21949 21950 As an example of this usage of `define_split', consider the following 21951 example from `a29k.md', which splits a `sign_extend' from `HImode' to 21952 `SImode' into a pair of shift insns: 21953 21954 (define_split 21955 [(set (match_operand:SI 0 "gen_reg_operand" "") 21956 (sign_extend:SI (match_operand:HI 1 "gen_reg_operand" "")))] 21957 "" 21958 [(set (match_dup 0) 21959 (ashift:SI (match_dup 1) 21960 (const_int 16))) 21961 (set (match_dup 0) 21962 (ashiftrt:SI (match_dup 0) 21963 (const_int 16)))] 21964 " 21965 { operands[1] = gen_lowpart (SImode, operands[1]); }") 21966 21967 When the combiner phase tries to split an insn pattern, it is always 21968 the case that the pattern is _not_ matched by any `define_insn'. The 21969 combiner pass first tries to split a single `set' expression and then 21970 the same `set' expression inside a `parallel', but followed by a 21971 `clobber' of a pseudo-reg to use as a scratch register. In these 21972 cases, the combiner expects exactly two new insn patterns to be 21973 generated. It will verify that these patterns match some `define_insn' 21974 definitions, so you need not do this test in the `define_split' (of 21975 course, there is no point in writing a `define_split' that will never 21976 produce insns that match). 21977 21978 Here is an example of this use of `define_split', taken from 21979 `rs6000.md': 21980 21981 (define_split 21982 [(set (match_operand:SI 0 "gen_reg_operand" "") 21983 (plus:SI (match_operand:SI 1 "gen_reg_operand" "") 21984 (match_operand:SI 2 "non_add_cint_operand" "")))] 21985 "" 21986 [(set (match_dup 0) (plus:SI (match_dup 1) (match_dup 3))) 21987 (set (match_dup 0) (plus:SI (match_dup 0) (match_dup 4)))] 21988 " 21989 { 21990 int low = INTVAL (operands[2]) & 0xffff; 21991 int high = (unsigned) INTVAL (operands[2]) >> 16; 21992 21993 if (low & 0x8000) 21994 high++, low |= 0xffff0000; 21995 21996 operands[3] = GEN_INT (high << 16); 21997 operands[4] = GEN_INT (low); 21998 }") 21999 22000 Here the predicate `non_add_cint_operand' matches any `const_int' that 22001 is _not_ a valid operand of a single add insn. The add with the 22002 smaller displacement is written so that it can be substituted into the 22003 address of a subsequent operation. 22004 22005 An example that uses a scratch register, from the same file, generates 22006 an equality comparison of a register and a large constant: 22007 22008 (define_split 22009 [(set (match_operand:CC 0 "cc_reg_operand" "") 22010 (compare:CC (match_operand:SI 1 "gen_reg_operand" "") 22011 (match_operand:SI 2 "non_short_cint_operand" ""))) 22012 (clobber (match_operand:SI 3 "gen_reg_operand" ""))] 22013 "find_single_use (operands[0], insn, 0) 22014 && (GET_CODE (*find_single_use (operands[0], insn, 0)) == EQ 22015 || GET_CODE (*find_single_use (operands[0], insn, 0)) == NE)" 22016 [(set (match_dup 3) (xor:SI (match_dup 1) (match_dup 4))) 22017 (set (match_dup 0) (compare:CC (match_dup 3) (match_dup 5)))] 22018 " 22019 { 22020 /* Get the constant we are comparing against, C, and see what it 22021 looks like sign-extended to 16 bits. Then see what constant 22022 could be XOR'ed with C to get the sign-extended value. */ 22023 22024 int c = INTVAL (operands[2]); 22025 int sextc = (c << 16) >> 16; 22026 int xorv = c ^ sextc; 22027 22028 operands[4] = GEN_INT (xorv); 22029 operands[5] = GEN_INT (sextc); 22030 }") 22031 22032 To avoid confusion, don't write a single `define_split' that accepts 22033 some insns that match some `define_insn' as well as some insns that 22034 don't. Instead, write two separate `define_split' definitions, one for 22035 the insns that are valid and one for the insns that are not valid. 22036 22037 The splitter is allowed to split jump instructions into sequence of 22038 jumps or create new jumps in while splitting non-jump instructions. As 22039 the central flowgraph and branch prediction information needs to be 22040 updated, several restriction apply. 22041 22042 Splitting of jump instruction into sequence that over by another jump 22043 instruction is always valid, as compiler expect identical behavior of 22044 new jump. When new sequence contains multiple jump instructions or new 22045 labels, more assistance is needed. Splitter is required to create only 22046 unconditional jumps, or simple conditional jump instructions. 22047 Additionally it must attach a `REG_BR_PROB' note to each conditional 22048 jump. A global variable `split_branch_probability' holds the 22049 probability of the original branch in case it was an simple conditional 22050 jump, -1 otherwise. To simplify recomputing of edge frequencies, the 22051 new sequence is required to have only forward jumps to the newly 22052 created labels. 22053 22054 For the common case where the pattern of a define_split exactly 22055 matches the pattern of a define_insn, use `define_insn_and_split'. It 22056 looks like this: 22057 22058 (define_insn_and_split 22059 [INSN-PATTERN] 22060 "CONDITION" 22061 "OUTPUT-TEMPLATE" 22062 "SPLIT-CONDITION" 22063 [NEW-INSN-PATTERN-1 22064 NEW-INSN-PATTERN-2 22065 ...] 22066 "PREPARATION-STATEMENTS" 22067 [INSN-ATTRIBUTES]) 22068 22069 INSN-PATTERN, CONDITION, OUTPUT-TEMPLATE, and INSN-ATTRIBUTES are used 22070 as in `define_insn'. The NEW-INSN-PATTERN vector and the 22071 PREPARATION-STATEMENTS are used as in a `define_split'. The 22072 SPLIT-CONDITION is also used as in `define_split', with the additional 22073 behavior that if the condition starts with `&&', the condition used for 22074 the split will be the constructed as a logical "and" of the split 22075 condition with the insn condition. For example, from i386.md: 22076 22077 (define_insn_and_split "zero_extendhisi2_and" 22078 [(set (match_operand:SI 0 "register_operand" "=r") 22079 (zero_extend:SI (match_operand:HI 1 "register_operand" "0"))) 22080 (clobber (reg:CC 17))] 22081 "TARGET_ZERO_EXTEND_WITH_AND && !optimize_size" 22082 "#" 22083 "&& reload_completed" 22084 [(parallel [(set (match_dup 0) 22085 (and:SI (match_dup 0) (const_int 65535))) 22086 (clobber (reg:CC 17))])] 22087 "" 22088 [(set_attr "type" "alu1")]) 22089 22090 In this case, the actual split condition will be 22091 `TARGET_ZERO_EXTEND_WITH_AND && !optimize_size && reload_completed'. 22092 22093 The `define_insn_and_split' construction provides exactly the same 22094 functionality as two separate `define_insn' and `define_split' 22095 patterns. It exists for compactness, and as a maintenance tool to 22096 prevent having to ensure the two patterns' templates match. 22097 22098 22099 File: gccint.info, Node: Including Patterns, Next: Peephole Definitions, Prev: Insn Splitting, Up: Machine Desc 22100 22101 16.17 Including Patterns in Machine Descriptions. 22102 ================================================= 22103 22104 The `include' pattern tells the compiler tools where to look for 22105 patterns that are in files other than in the file `.md'. This is used 22106 only at build time and there is no preprocessing allowed. 22107 22108 It looks like: 22109 22110 22111 (include 22112 PATHNAME) 22113 22114 For example: 22115 22116 22117 (include "filestuff") 22118 22119 Where PATHNAME is a string that specifies the location of the file, 22120 specifies the include file to be in `gcc/config/target/filestuff'. The 22121 directory `gcc/config/target' is regarded as the default directory. 22122 22123 Machine descriptions may be split up into smaller more manageable 22124 subsections and placed into subdirectories. 22125 22126 By specifying: 22127 22128 22129 (include "BOGUS/filestuff") 22130 22131 the include file is specified to be in 22132 `gcc/config/TARGET/BOGUS/filestuff'. 22133 22134 Specifying an absolute path for the include file such as; 22135 22136 (include "/u2/BOGUS/filestuff") 22137 is permitted but is not encouraged. 22138 22139 16.17.1 RTL Generation Tool Options for Directory Search 22140 -------------------------------------------------------- 22141 22142 The `-IDIR' option specifies directories to search for machine 22143 descriptions. For example: 22144 22145 22146 genrecog -I/p1/abc/proc1 -I/p2/abcd/pro2 target.md 22147 22148 Add the directory DIR to the head of the list of directories to be 22149 searched for header files. This can be used to override a system 22150 machine definition file, substituting your own version, since these 22151 directories are searched before the default machine description file 22152 directories. If you use more than one `-I' option, the directories are 22153 scanned in left-to-right order; the standard default directory come 22154 after. 22155 22156 22157 File: gccint.info, Node: Peephole Definitions, Next: Insn Attributes, Prev: Including Patterns, Up: Machine Desc 22158 22159 16.18 Machine-Specific Peephole Optimizers 22160 ========================================== 22161 22162 In addition to instruction patterns the `md' file may contain 22163 definitions of machine-specific peephole optimizations. 22164 22165 The combiner does not notice certain peephole optimizations when the 22166 data flow in the program does not suggest that it should try them. For 22167 example, sometimes two consecutive insns related in purpose can be 22168 combined even though the second one does not appear to use a register 22169 computed in the first one. A machine-specific peephole optimizer can 22170 detect such opportunities. 22171 22172 There are two forms of peephole definitions that may be used. The 22173 original `define_peephole' is run at assembly output time to match 22174 insns and substitute assembly text. Use of `define_peephole' is 22175 deprecated. 22176 22177 A newer `define_peephole2' matches insns and substitutes new insns. 22178 The `peephole2' pass is run after register allocation but before 22179 scheduling, which may result in much better code for targets that do 22180 scheduling. 22181 22182 * Menu: 22183 22184 * define_peephole:: RTL to Text Peephole Optimizers 22185 * define_peephole2:: RTL to RTL Peephole Optimizers 22186 22187 22188 File: gccint.info, Node: define_peephole, Next: define_peephole2, Up: Peephole Definitions 22189 22190 16.18.1 RTL to Text Peephole Optimizers 22191 --------------------------------------- 22192 22193 A definition looks like this: 22194 22195 (define_peephole 22196 [INSN-PATTERN-1 22197 INSN-PATTERN-2 22198 ...] 22199 "CONDITION" 22200 "TEMPLATE" 22201 "OPTIONAL-INSN-ATTRIBUTES") 22202 22203 The last string operand may be omitted if you are not using any 22204 machine-specific information in this machine description. If present, 22205 it must obey the same rules as in a `define_insn'. 22206 22207 In this skeleton, INSN-PATTERN-1 and so on are patterns to match 22208 consecutive insns. The optimization applies to a sequence of insns when 22209 INSN-PATTERN-1 matches the first one, INSN-PATTERN-2 matches the next, 22210 and so on. 22211 22212 Each of the insns matched by a peephole must also match a 22213 `define_insn'. Peepholes are checked only at the last stage just 22214 before code generation, and only optionally. Therefore, any insn which 22215 would match a peephole but no `define_insn' will cause a crash in code 22216 generation in an unoptimized compilation, or at various optimization 22217 stages. 22218 22219 The operands of the insns are matched with `match_operands', 22220 `match_operator', and `match_dup', as usual. What is not usual is that 22221 the operand numbers apply to all the insn patterns in the definition. 22222 So, you can check for identical operands in two insns by using 22223 `match_operand' in one insn and `match_dup' in the other. 22224 22225 The operand constraints used in `match_operand' patterns do not have 22226 any direct effect on the applicability of the peephole, but they will 22227 be validated afterward, so make sure your constraints are general enough 22228 to apply whenever the peephole matches. If the peephole matches but 22229 the constraints are not satisfied, the compiler will crash. 22230 22231 It is safe to omit constraints in all the operands of the peephole; or 22232 you can write constraints which serve as a double-check on the criteria 22233 previously tested. 22234 22235 Once a sequence of insns matches the patterns, the CONDITION is 22236 checked. This is a C expression which makes the final decision whether 22237 to perform the optimization (we do so if the expression is nonzero). If 22238 CONDITION is omitted (in other words, the string is empty) then the 22239 optimization is applied to every sequence of insns that matches the 22240 patterns. 22241 22242 The defined peephole optimizations are applied after register 22243 allocation is complete. Therefore, the peephole definition can check 22244 which operands have ended up in which kinds of registers, just by 22245 looking at the operands. 22246 22247 The way to refer to the operands in CONDITION is to write 22248 `operands[I]' for operand number I (as matched by `(match_operand I 22249 ...)'). Use the variable `insn' to refer to the last of the insns 22250 being matched; use `prev_active_insn' to find the preceding insns. 22251 22252 When optimizing computations with intermediate results, you can use 22253 CONDITION to match only when the intermediate results are not used 22254 elsewhere. Use the C expression `dead_or_set_p (INSN, OP)', where INSN 22255 is the insn in which you expect the value to be used for the last time 22256 (from the value of `insn', together with use of `prev_nonnote_insn'), 22257 and OP is the intermediate value (from `operands[I]'). 22258 22259 Applying the optimization means replacing the sequence of insns with 22260 one new insn. The TEMPLATE controls ultimate output of assembler code 22261 for this combined insn. It works exactly like the template of a 22262 `define_insn'. Operand numbers in this template are the same ones used 22263 in matching the original sequence of insns. 22264 22265 The result of a defined peephole optimizer does not need to match any 22266 of the insn patterns in the machine description; it does not even have 22267 an opportunity to match them. The peephole optimizer definition itself 22268 serves as the insn pattern to control how the insn is output. 22269 22270 Defined peephole optimizers are run as assembler code is being output, 22271 so the insns they produce are never combined or rearranged in any way. 22272 22273 Here is an example, taken from the 68000 machine description: 22274 22275 (define_peephole 22276 [(set (reg:SI 15) (plus:SI (reg:SI 15) (const_int 4))) 22277 (set (match_operand:DF 0 "register_operand" "=f") 22278 (match_operand:DF 1 "register_operand" "ad"))] 22279 "FP_REG_P (operands[0]) && ! FP_REG_P (operands[1])" 22280 { 22281 rtx xoperands[2]; 22282 xoperands[1] = gen_rtx_REG (SImode, REGNO (operands[1]) + 1); 22283 #ifdef MOTOROLA 22284 output_asm_insn ("move.l %1,(sp)", xoperands); 22285 output_asm_insn ("move.l %1,-(sp)", operands); 22286 return "fmove.d (sp)+,%0"; 22287 #else 22288 output_asm_insn ("movel %1,sp@", xoperands); 22289 output_asm_insn ("movel %1,sp@-", operands); 22290 return "fmoved sp@+,%0"; 22291 #endif 22292 }) 22293 22294 The effect of this optimization is to change 22295 22296 jbsr _foobar 22297 addql #4,sp 22298 movel d1,sp@- 22299 movel d0,sp@- 22300 fmoved sp@+,fp0 22301 22302 into 22303 22304 jbsr _foobar 22305 movel d1,sp@ 22306 movel d0,sp@- 22307 fmoved sp@+,fp0 22308 22309 INSN-PATTERN-1 and so on look _almost_ like the second operand of 22310 `define_insn'. There is one important difference: the second operand 22311 of `define_insn' consists of one or more RTX's enclosed in square 22312 brackets. Usually, there is only one: then the same action can be 22313 written as an element of a `define_peephole'. But when there are 22314 multiple actions in a `define_insn', they are implicitly enclosed in a 22315 `parallel'. Then you must explicitly write the `parallel', and the 22316 square brackets within it, in the `define_peephole'. Thus, if an insn 22317 pattern looks like this, 22318 22319 (define_insn "divmodsi4" 22320 [(set (match_operand:SI 0 "general_operand" "=d") 22321 (div:SI (match_operand:SI 1 "general_operand" "0") 22322 (match_operand:SI 2 "general_operand" "dmsK"))) 22323 (set (match_operand:SI 3 "general_operand" "=d") 22324 (mod:SI (match_dup 1) (match_dup 2)))] 22325 "TARGET_68020" 22326 "divsl%.l %2,%3:%0") 22327 22328 then the way to mention this insn in a peephole is as follows: 22329 22330 (define_peephole 22331 [... 22332 (parallel 22333 [(set (match_operand:SI 0 "general_operand" "=d") 22334 (div:SI (match_operand:SI 1 "general_operand" "0") 22335 (match_operand:SI 2 "general_operand" "dmsK"))) 22336 (set (match_operand:SI 3 "general_operand" "=d") 22337 (mod:SI (match_dup 1) (match_dup 2)))]) 22338 ...] 22339 ...) 22340 22341 22342 File: gccint.info, Node: define_peephole2, Prev: define_peephole, Up: Peephole Definitions 22343 22344 16.18.2 RTL to RTL Peephole Optimizers 22345 -------------------------------------- 22346 22347 The `define_peephole2' definition tells the compiler how to substitute 22348 one sequence of instructions for another sequence, what additional 22349 scratch registers may be needed and what their lifetimes must be. 22350 22351 (define_peephole2 22352 [INSN-PATTERN-1 22353 INSN-PATTERN-2 22354 ...] 22355 "CONDITION" 22356 [NEW-INSN-PATTERN-1 22357 NEW-INSN-PATTERN-2 22358 ...] 22359 "PREPARATION-STATEMENTS") 22360 22361 The definition is almost identical to `define_split' (*note Insn 22362 Splitting::) except that the pattern to match is not a single 22363 instruction, but a sequence of instructions. 22364 22365 It is possible to request additional scratch registers for use in the 22366 output template. If appropriate registers are not free, the pattern 22367 will simply not match. 22368 22369 Scratch registers are requested with a `match_scratch' pattern at the 22370 top level of the input pattern. The allocated register (initially) will 22371 be dead at the point requested within the original sequence. If the 22372 scratch is used at more than a single point, a `match_dup' pattern at 22373 the top level of the input pattern marks the last position in the input 22374 sequence at which the register must be available. 22375 22376 Here is an example from the IA-32 machine description: 22377 22378 (define_peephole2 22379 [(match_scratch:SI 2 "r") 22380 (parallel [(set (match_operand:SI 0 "register_operand" "") 22381 (match_operator:SI 3 "arith_or_logical_operator" 22382 [(match_dup 0) 22383 (match_operand:SI 1 "memory_operand" "")])) 22384 (clobber (reg:CC 17))])] 22385 "! optimize_size && ! TARGET_READ_MODIFY" 22386 [(set (match_dup 2) (match_dup 1)) 22387 (parallel [(set (match_dup 0) 22388 (match_op_dup 3 [(match_dup 0) (match_dup 2)])) 22389 (clobber (reg:CC 17))])] 22390 "") 22391 22392 This pattern tries to split a load from its use in the hopes that we'll 22393 be able to schedule around the memory load latency. It allocates a 22394 single `SImode' register of class `GENERAL_REGS' (`"r"') that needs to 22395 be live only at the point just before the arithmetic. 22396 22397 A real example requiring extended scratch lifetimes is harder to come 22398 by, so here's a silly made-up example: 22399 22400 (define_peephole2 22401 [(match_scratch:SI 4 "r") 22402 (set (match_operand:SI 0 "" "") (match_operand:SI 1 "" "")) 22403 (set (match_operand:SI 2 "" "") (match_dup 1)) 22404 (match_dup 4) 22405 (set (match_operand:SI 3 "" "") (match_dup 1))] 22406 "/* determine 1 does not overlap 0 and 2 */" 22407 [(set (match_dup 4) (match_dup 1)) 22408 (set (match_dup 0) (match_dup 4)) 22409 (set (match_dup 2) (match_dup 4))] 22410 (set (match_dup 3) (match_dup 4))] 22411 "") 22412 22413 If we had not added the `(match_dup 4)' in the middle of the input 22414 sequence, it might have been the case that the register we chose at the 22415 beginning of the sequence is killed by the first or second `set'. 22416 22417 22418 File: gccint.info, Node: Insn Attributes, Next: Conditional Execution, Prev: Peephole Definitions, Up: Machine Desc 22419 22420 16.19 Instruction Attributes 22421 ============================ 22422 22423 In addition to describing the instruction supported by the target 22424 machine, the `md' file also defines a group of "attributes" and a set of 22425 values for each. Every generated insn is assigned a value for each 22426 attribute. One possible attribute would be the effect that the insn 22427 has on the machine's condition code. This attribute can then be used 22428 by `NOTICE_UPDATE_CC' to track the condition codes. 22429 22430 * Menu: 22431 22432 * Defining Attributes:: Specifying attributes and their values. 22433 * Expressions:: Valid expressions for attribute values. 22434 * Tagging Insns:: Assigning attribute values to insns. 22435 * Attr Example:: An example of assigning attributes. 22436 * Insn Lengths:: Computing the length of insns. 22437 * Constant Attributes:: Defining attributes that are constant. 22438 * Delay Slots:: Defining delay slots required for a machine. 22439 * Processor pipeline description:: Specifying information for insn scheduling. 22440 22441 22442 File: gccint.info, Node: Defining Attributes, Next: Expressions, Up: Insn Attributes 22443 22444 16.19.1 Defining Attributes and their Values 22445 -------------------------------------------- 22446 22447 The `define_attr' expression is used to define each attribute required 22448 by the target machine. It looks like: 22449 22450 (define_attr NAME LIST-OF-VALUES DEFAULT) 22451 22452 NAME is a string specifying the name of the attribute being defined. 22453 22454 LIST-OF-VALUES is either a string that specifies a comma-separated 22455 list of values that can be assigned to the attribute, or a null string 22456 to indicate that the attribute takes numeric values. 22457 22458 DEFAULT is an attribute expression that gives the value of this 22459 attribute for insns that match patterns whose definition does not 22460 include an explicit value for this attribute. *Note Attr Example::, 22461 for more information on the handling of defaults. *Note Constant 22462 Attributes::, for information on attributes that do not depend on any 22463 particular insn. 22464 22465 For each defined attribute, a number of definitions are written to the 22466 `insn-attr.h' file. For cases where an explicit set of values is 22467 specified for an attribute, the following are defined: 22468 22469 * A `#define' is written for the symbol `HAVE_ATTR_NAME'. 22470 22471 * An enumerated class is defined for `attr_NAME' with elements of 22472 the form `UPPER-NAME_UPPER-VALUE' where the attribute name and 22473 value are first converted to uppercase. 22474 22475 * A function `get_attr_NAME' is defined that is passed an insn and 22476 returns the attribute value for that insn. 22477 22478 For example, if the following is present in the `md' file: 22479 22480 (define_attr "type" "branch,fp,load,store,arith" ...) 22481 22482 the following lines will be written to the file `insn-attr.h'. 22483 22484 #define HAVE_ATTR_type 22485 enum attr_type {TYPE_BRANCH, TYPE_FP, TYPE_LOAD, 22486 TYPE_STORE, TYPE_ARITH}; 22487 extern enum attr_type get_attr_type (); 22488 22489 If the attribute takes numeric values, no `enum' type will be defined 22490 and the function to obtain the attribute's value will return `int'. 22491 22492 There are attributes which are tied to a specific meaning. These 22493 attributes are not free to use for other purposes: 22494 22495 `length' 22496 The `length' attribute is used to calculate the length of emitted 22497 code chunks. This is especially important when verifying branch 22498 distances. *Note Insn Lengths::. 22499 22500 `enabled' 22501 The `enabled' attribute can be defined to prevent certain 22502 alternatives of an insn definition from being used during code 22503 generation. *Note Disable Insn Alternatives::. 22504 22505 22506 22507 File: gccint.info, Node: Expressions, Next: Tagging Insns, Prev: Defining Attributes, Up: Insn Attributes 22508 22509 16.19.2 Attribute Expressions 22510 ----------------------------- 22511 22512 RTL expressions used to define attributes use the codes described above 22513 plus a few specific to attribute definitions, to be discussed below. 22514 Attribute value expressions must have one of the following forms: 22515 22516 `(const_int I)' 22517 The integer I specifies the value of a numeric attribute. I must 22518 be non-negative. 22519 22520 The value of a numeric attribute can be specified either with a 22521 `const_int', or as an integer represented as a string in 22522 `const_string', `eq_attr' (see below), `attr', `symbol_ref', 22523 simple arithmetic expressions, and `set_attr' overrides on 22524 specific instructions (*note Tagging Insns::). 22525 22526 `(const_string VALUE)' 22527 The string VALUE specifies a constant attribute value. If VALUE 22528 is specified as `"*"', it means that the default value of the 22529 attribute is to be used for the insn containing this expression. 22530 `"*"' obviously cannot be used in the DEFAULT expression of a 22531 `define_attr'. 22532 22533 If the attribute whose value is being specified is numeric, VALUE 22534 must be a string containing a non-negative integer (normally 22535 `const_int' would be used in this case). Otherwise, it must 22536 contain one of the valid values for the attribute. 22537 22538 `(if_then_else TEST TRUE-VALUE FALSE-VALUE)' 22539 TEST specifies an attribute test, whose format is defined below. 22540 The value of this expression is TRUE-VALUE if TEST is true, 22541 otherwise it is FALSE-VALUE. 22542 22543 `(cond [TEST1 VALUE1 ...] DEFAULT)' 22544 The first operand of this expression is a vector containing an even 22545 number of expressions and consisting of pairs of TEST and VALUE 22546 expressions. The value of the `cond' expression is that of the 22547 VALUE corresponding to the first true TEST expression. If none of 22548 the TEST expressions are true, the value of the `cond' expression 22549 is that of the DEFAULT expression. 22550 22551 TEST expressions can have one of the following forms: 22552 22553 `(const_int I)' 22554 This test is true if I is nonzero and false otherwise. 22555 22556 `(not TEST)' 22557 `(ior TEST1 TEST2)' 22558 `(and TEST1 TEST2)' 22559 These tests are true if the indicated logical function is true. 22560 22561 `(match_operand:M N PRED CONSTRAINTS)' 22562 This test is true if operand N of the insn whose attribute value 22563 is being determined has mode M (this part of the test is ignored 22564 if M is `VOIDmode') and the function specified by the string PRED 22565 returns a nonzero value when passed operand N and mode M (this 22566 part of the test is ignored if PRED is the null string). 22567 22568 The CONSTRAINTS operand is ignored and should be the null string. 22569 22570 `(le ARITH1 ARITH2)' 22571 `(leu ARITH1 ARITH2)' 22572 `(lt ARITH1 ARITH2)' 22573 `(ltu ARITH1 ARITH2)' 22574 `(gt ARITH1 ARITH2)' 22575 `(gtu ARITH1 ARITH2)' 22576 `(ge ARITH1 ARITH2)' 22577 `(geu ARITH1 ARITH2)' 22578 `(ne ARITH1 ARITH2)' 22579 `(eq ARITH1 ARITH2)' 22580 These tests are true if the indicated comparison of the two 22581 arithmetic expressions is true. Arithmetic expressions are formed 22582 with `plus', `minus', `mult', `div', `mod', `abs', `neg', `and', 22583 `ior', `xor', `not', `ashift', `lshiftrt', and `ashiftrt' 22584 expressions. 22585 22586 `const_int' and `symbol_ref' are always valid terms (*note Insn 22587 Lengths::,for additional forms). `symbol_ref' is a string 22588 denoting a C expression that yields an `int' when evaluated by the 22589 `get_attr_...' routine. It should normally be a global variable. 22590 22591 `(eq_attr NAME VALUE)' 22592 NAME is a string specifying the name of an attribute. 22593 22594 VALUE is a string that is either a valid value for attribute NAME, 22595 a comma-separated list of values, or `!' followed by a value or 22596 list. If VALUE does not begin with a `!', this test is true if 22597 the value of the NAME attribute of the current insn is in the list 22598 specified by VALUE. If VALUE begins with a `!', this test is true 22599 if the attribute's value is _not_ in the specified list. 22600 22601 For example, 22602 22603 (eq_attr "type" "load,store") 22604 22605 is equivalent to 22606 22607 (ior (eq_attr "type" "load") (eq_attr "type" "store")) 22608 22609 If NAME specifies an attribute of `alternative', it refers to the 22610 value of the compiler variable `which_alternative' (*note Output 22611 Statement::) and the values must be small integers. For example, 22612 22613 (eq_attr "alternative" "2,3") 22614 22615 is equivalent to 22616 22617 (ior (eq (symbol_ref "which_alternative") (const_int 2)) 22618 (eq (symbol_ref "which_alternative") (const_int 3))) 22619 22620 Note that, for most attributes, an `eq_attr' test is simplified in 22621 cases where the value of the attribute being tested is known for 22622 all insns matching a particular pattern. This is by far the most 22623 common case. 22624 22625 `(attr_flag NAME)' 22626 The value of an `attr_flag' expression is true if the flag 22627 specified by NAME is true for the `insn' currently being scheduled. 22628 22629 NAME is a string specifying one of a fixed set of flags to test. 22630 Test the flags `forward' and `backward' to determine the direction 22631 of a conditional branch. Test the flags `very_likely', `likely', 22632 `very_unlikely', and `unlikely' to determine if a conditional 22633 branch is expected to be taken. 22634 22635 If the `very_likely' flag is true, then the `likely' flag is also 22636 true. Likewise for the `very_unlikely' and `unlikely' flags. 22637 22638 This example describes a conditional branch delay slot which can 22639 be nullified for forward branches that are taken (annul-true) or 22640 for backward branches which are not taken (annul-false). 22641 22642 (define_delay (eq_attr "type" "cbranch") 22643 [(eq_attr "in_branch_delay" "true") 22644 (and (eq_attr "in_branch_delay" "true") 22645 (attr_flag "forward")) 22646 (and (eq_attr "in_branch_delay" "true") 22647 (attr_flag "backward"))]) 22648 22649 The `forward' and `backward' flags are false if the current `insn' 22650 being scheduled is not a conditional branch. 22651 22652 The `very_likely' and `likely' flags are true if the `insn' being 22653 scheduled is not a conditional branch. The `very_unlikely' and 22654 `unlikely' flags are false if the `insn' being scheduled is not a 22655 conditional branch. 22656 22657 `attr_flag' is only used during delay slot scheduling and has no 22658 meaning to other passes of the compiler. 22659 22660 `(attr NAME)' 22661 The value of another attribute is returned. This is most useful 22662 for numeric attributes, as `eq_attr' and `attr_flag' produce more 22663 efficient code for non-numeric attributes. 22664 22665 22666 File: gccint.info, Node: Tagging Insns, Next: Attr Example, Prev: Expressions, Up: Insn Attributes 22667 22668 16.19.3 Assigning Attribute Values to Insns 22669 ------------------------------------------- 22670 22671 The value assigned to an attribute of an insn is primarily determined by 22672 which pattern is matched by that insn (or which `define_peephole' 22673 generated it). Every `define_insn' and `define_peephole' can have an 22674 optional last argument to specify the values of attributes for matching 22675 insns. The value of any attribute not specified in a particular insn 22676 is set to the default value for that attribute, as specified in its 22677 `define_attr'. Extensive use of default values for attributes permits 22678 the specification of the values for only one or two attributes in the 22679 definition of most insn patterns, as seen in the example in the next 22680 section. 22681 22682 The optional last argument of `define_insn' and `define_peephole' is a 22683 vector of expressions, each of which defines the value for a single 22684 attribute. The most general way of assigning an attribute's value is 22685 to use a `set' expression whose first operand is an `attr' expression 22686 giving the name of the attribute being set. The second operand of the 22687 `set' is an attribute expression (*note Expressions::) giving the value 22688 of the attribute. 22689 22690 When the attribute value depends on the `alternative' attribute (i.e., 22691 which is the applicable alternative in the constraint of the insn), the 22692 `set_attr_alternative' expression can be used. It allows the 22693 specification of a vector of attribute expressions, one for each 22694 alternative. 22695 22696 When the generality of arbitrary attribute expressions is not required, 22697 the simpler `set_attr' expression can be used, which allows specifying 22698 a string giving either a single attribute value or a list of attribute 22699 values, one for each alternative. 22700 22701 The form of each of the above specifications is shown below. In each 22702 case, NAME is a string specifying the attribute to be set. 22703 22704 `(set_attr NAME VALUE-STRING)' 22705 VALUE-STRING is either a string giving the desired attribute value, 22706 or a string containing a comma-separated list giving the values for 22707 succeeding alternatives. The number of elements must match the 22708 number of alternatives in the constraint of the insn pattern. 22709 22710 Note that it may be useful to specify `*' for some alternative, in 22711 which case the attribute will assume its default value for insns 22712 matching that alternative. 22713 22714 `(set_attr_alternative NAME [VALUE1 VALUE2 ...])' 22715 Depending on the alternative of the insn, the value will be one of 22716 the specified values. This is a shorthand for using a `cond' with 22717 tests on the `alternative' attribute. 22718 22719 `(set (attr NAME) VALUE)' 22720 The first operand of this `set' must be the special RTL expression 22721 `attr', whose sole operand is a string giving the name of the 22722 attribute being set. VALUE is the value of the attribute. 22723 22724 The following shows three different ways of representing the same 22725 attribute value specification: 22726 22727 (set_attr "type" "load,store,arith") 22728 22729 (set_attr_alternative "type" 22730 [(const_string "load") (const_string "store") 22731 (const_string "arith")]) 22732 22733 (set (attr "type") 22734 (cond [(eq_attr "alternative" "1") (const_string "load") 22735 (eq_attr "alternative" "2") (const_string "store")] 22736 (const_string "arith"))) 22737 22738 The `define_asm_attributes' expression provides a mechanism to specify 22739 the attributes assigned to insns produced from an `asm' statement. It 22740 has the form: 22741 22742 (define_asm_attributes [ATTR-SETS]) 22743 22744 where ATTR-SETS is specified the same as for both the `define_insn' and 22745 the `define_peephole' expressions. 22746 22747 These values will typically be the "worst case" attribute values. For 22748 example, they might indicate that the condition code will be clobbered. 22749 22750 A specification for a `length' attribute is handled specially. The 22751 way to compute the length of an `asm' insn is to multiply the length 22752 specified in the expression `define_asm_attributes' by the number of 22753 machine instructions specified in the `asm' statement, determined by 22754 counting the number of semicolons and newlines in the string. 22755 Therefore, the value of the `length' attribute specified in a 22756 `define_asm_attributes' should be the maximum possible length of a 22757 single machine instruction. 22758 22759 22760 File: gccint.info, Node: Attr Example, Next: Insn Lengths, Prev: Tagging Insns, Up: Insn Attributes 22761 22762 16.19.4 Example of Attribute Specifications 22763 ------------------------------------------- 22764 22765 The judicious use of defaulting is important in the efficient use of 22766 insn attributes. Typically, insns are divided into "types" and an 22767 attribute, customarily called `type', is used to represent this value. 22768 This attribute is normally used only to define the default value for 22769 other attributes. An example will clarify this usage. 22770 22771 Assume we have a RISC machine with a condition code and in which only 22772 full-word operations are performed in registers. Let us assume that we 22773 can divide all insns into loads, stores, (integer) arithmetic 22774 operations, floating point operations, and branches. 22775 22776 Here we will concern ourselves with determining the effect of an insn 22777 on the condition code and will limit ourselves to the following possible 22778 effects: The condition code can be set unpredictably (clobbered), not 22779 be changed, be set to agree with the results of the operation, or only 22780 changed if the item previously set into the condition code has been 22781 modified. 22782 22783 Here is part of a sample `md' file for such a machine: 22784 22785 (define_attr "type" "load,store,arith,fp,branch" (const_string "arith")) 22786 22787 (define_attr "cc" "clobber,unchanged,set,change0" 22788 (cond [(eq_attr "type" "load") 22789 (const_string "change0") 22790 (eq_attr "type" "store,branch") 22791 (const_string "unchanged") 22792 (eq_attr "type" "arith") 22793 (if_then_else (match_operand:SI 0 "" "") 22794 (const_string "set") 22795 (const_string "clobber"))] 22796 (const_string "clobber"))) 22797 22798 (define_insn "" 22799 [(set (match_operand:SI 0 "general_operand" "=r,r,m") 22800 (match_operand:SI 1 "general_operand" "r,m,r"))] 22801 "" 22802 "@ 22803 move %0,%1 22804 load %0,%1 22805 store %0,%1" 22806 [(set_attr "type" "arith,load,store")]) 22807 22808 Note that we assume in the above example that arithmetic operations 22809 performed on quantities smaller than a machine word clobber the 22810 condition code since they will set the condition code to a value 22811 corresponding to the full-word result. 22812 22813 22814 File: gccint.info, Node: Insn Lengths, Next: Constant Attributes, Prev: Attr Example, Up: Insn Attributes 22815 22816 16.19.5 Computing the Length of an Insn 22817 --------------------------------------- 22818 22819 For many machines, multiple types of branch instructions are provided, 22820 each for different length branch displacements. In most cases, the 22821 assembler will choose the correct instruction to use. However, when 22822 the assembler cannot do so, GCC can when a special attribute, the 22823 `length' attribute, is defined. This attribute must be defined to have 22824 numeric values by specifying a null string in its `define_attr'. 22825 22826 In the case of the `length' attribute, two additional forms of 22827 arithmetic terms are allowed in test expressions: 22828 22829 `(match_dup N)' 22830 This refers to the address of operand N of the current insn, which 22831 must be a `label_ref'. 22832 22833 `(pc)' 22834 This refers to the address of the _current_ insn. It might have 22835 been more consistent with other usage to make this the address of 22836 the _next_ insn but this would be confusing because the length of 22837 the current insn is to be computed. 22838 22839 For normal insns, the length will be determined by value of the 22840 `length' attribute. In the case of `addr_vec' and `addr_diff_vec' insn 22841 patterns, the length is computed as the number of vectors multiplied by 22842 the size of each vector. 22843 22844 Lengths are measured in addressable storage units (bytes). 22845 22846 The following macros can be used to refine the length computation: 22847 22848 `ADJUST_INSN_LENGTH (INSN, LENGTH)' 22849 If defined, modifies the length assigned to instruction INSN as a 22850 function of the context in which it is used. LENGTH is an lvalue 22851 that contains the initially computed length of the insn and should 22852 be updated with the correct length of the insn. 22853 22854 This macro will normally not be required. A case in which it is 22855 required is the ROMP. On this machine, the size of an `addr_vec' 22856 insn must be increased by two to compensate for the fact that 22857 alignment may be required. 22858 22859 The routine that returns `get_attr_length' (the value of the `length' 22860 attribute) can be used by the output routine to determine the form of 22861 the branch instruction to be written, as the example below illustrates. 22862 22863 As an example of the specification of variable-length branches, 22864 consider the IBM 360. If we adopt the convention that a register will 22865 be set to the starting address of a function, we can jump to labels 22866 within 4k of the start using a four-byte instruction. Otherwise, we 22867 need a six-byte sequence to load the address from memory and then 22868 branch to it. 22869 22870 On such a machine, a pattern for a branch instruction might be 22871 specified as follows: 22872 22873 (define_insn "jump" 22874 [(set (pc) 22875 (label_ref (match_operand 0 "" "")))] 22876 "" 22877 { 22878 return (get_attr_length (insn) == 4 22879 ? "b %l0" : "l r15,=a(%l0); br r15"); 22880 } 22881 [(set (attr "length") 22882 (if_then_else (lt (match_dup 0) (const_int 4096)) 22883 (const_int 4) 22884 (const_int 6)))]) 22885 22886 22887 File: gccint.info, Node: Constant Attributes, Next: Delay Slots, Prev: Insn Lengths, Up: Insn Attributes 22888 22889 16.19.6 Constant Attributes 22890 --------------------------- 22891 22892 A special form of `define_attr', where the expression for the default 22893 value is a `const' expression, indicates an attribute that is constant 22894 for a given run of the compiler. Constant attributes may be used to 22895 specify which variety of processor is used. For example, 22896 22897 (define_attr "cpu" "m88100,m88110,m88000" 22898 (const 22899 (cond [(symbol_ref "TARGET_88100") (const_string "m88100") 22900 (symbol_ref "TARGET_88110") (const_string "m88110")] 22901 (const_string "m88000")))) 22902 22903 (define_attr "memory" "fast,slow" 22904 (const 22905 (if_then_else (symbol_ref "TARGET_FAST_MEM") 22906 (const_string "fast") 22907 (const_string "slow")))) 22908 22909 The routine generated for constant attributes has no parameters as it 22910 does not depend on any particular insn. RTL expressions used to define 22911 the value of a constant attribute may use the `symbol_ref' form, but 22912 may not use either the `match_operand' form or `eq_attr' forms 22913 involving insn attributes. 22914 22915 22916 File: gccint.info, Node: Delay Slots, Next: Processor pipeline description, Prev: Constant Attributes, Up: Insn Attributes 22917 22918 16.19.7 Delay Slot Scheduling 22919 ----------------------------- 22920 22921 The insn attribute mechanism can be used to specify the requirements for 22922 delay slots, if any, on a target machine. An instruction is said to 22923 require a "delay slot" if some instructions that are physically after 22924 the instruction are executed as if they were located before it. 22925 Classic examples are branch and call instructions, which often execute 22926 the following instruction before the branch or call is performed. 22927 22928 On some machines, conditional branch instructions can optionally 22929 "annul" instructions in the delay slot. This means that the 22930 instruction will not be executed for certain branch outcomes. Both 22931 instructions that annul if the branch is true and instructions that 22932 annul if the branch is false are supported. 22933 22934 Delay slot scheduling differs from instruction scheduling in that 22935 determining whether an instruction needs a delay slot is dependent only 22936 on the type of instruction being generated, not on data flow between the 22937 instructions. See the next section for a discussion of data-dependent 22938 instruction scheduling. 22939 22940 The requirement of an insn needing one or more delay slots is indicated 22941 via the `define_delay' expression. It has the following form: 22942 22943 (define_delay TEST 22944 [DELAY-1 ANNUL-TRUE-1 ANNUL-FALSE-1 22945 DELAY-2 ANNUL-TRUE-2 ANNUL-FALSE-2 22946 ...]) 22947 22948 TEST is an attribute test that indicates whether this `define_delay' 22949 applies to a particular insn. If so, the number of required delay 22950 slots is determined by the length of the vector specified as the second 22951 argument. An insn placed in delay slot N must satisfy attribute test 22952 DELAY-N. ANNUL-TRUE-N is an attribute test that specifies which insns 22953 may be annulled if the branch is true. Similarly, ANNUL-FALSE-N 22954 specifies which insns in the delay slot may be annulled if the branch 22955 is false. If annulling is not supported for that delay slot, `(nil)' 22956 should be coded. 22957 22958 For example, in the common case where branch and call insns require a 22959 single delay slot, which may contain any insn other than a branch or 22960 call, the following would be placed in the `md' file: 22961 22962 (define_delay (eq_attr "type" "branch,call") 22963 [(eq_attr "type" "!branch,call") (nil) (nil)]) 22964 22965 Multiple `define_delay' expressions may be specified. In this case, 22966 each such expression specifies different delay slot requirements and 22967 there must be no insn for which tests in two `define_delay' expressions 22968 are both true. 22969 22970 For example, if we have a machine that requires one delay slot for 22971 branches but two for calls, no delay slot can contain a branch or call 22972 insn, and any valid insn in the delay slot for the branch can be 22973 annulled if the branch is true, we might represent this as follows: 22974 22975 (define_delay (eq_attr "type" "branch") 22976 [(eq_attr "type" "!branch,call") 22977 (eq_attr "type" "!branch,call") 22978 (nil)]) 22979 22980 (define_delay (eq_attr "type" "call") 22981 [(eq_attr "type" "!branch,call") (nil) (nil) 22982 (eq_attr "type" "!branch,call") (nil) (nil)]) 22983 22984 22985 File: gccint.info, Node: Processor pipeline description, Prev: Delay Slots, Up: Insn Attributes 22986 22987 16.19.8 Specifying processor pipeline description 22988 ------------------------------------------------- 22989 22990 To achieve better performance, most modern processors (super-pipelined, 22991 superscalar RISC, and VLIW processors) have many "functional units" on 22992 which several instructions can be executed simultaneously. An 22993 instruction starts execution if its issue conditions are satisfied. If 22994 not, the instruction is stalled until its conditions are satisfied. 22995 Such "interlock (pipeline) delay" causes interruption of the fetching 22996 of successor instructions (or demands nop instructions, e.g. for some 22997 MIPS processors). 22998 22999 There are two major kinds of interlock delays in modern processors. 23000 The first one is a data dependence delay determining "instruction 23001 latency time". The instruction execution is not started until all 23002 source data have been evaluated by prior instructions (there are more 23003 complex cases when the instruction execution starts even when the data 23004 are not available but will be ready in given time after the instruction 23005 execution start). Taking the data dependence delays into account is 23006 simple. The data dependence (true, output, and anti-dependence) delay 23007 between two instructions is given by a constant. In most cases this 23008 approach is adequate. The second kind of interlock delays is a 23009 reservation delay. The reservation delay means that two instructions 23010 under execution will be in need of shared processors resources, i.e. 23011 buses, internal registers, and/or functional units, which are reserved 23012 for some time. Taking this kind of delay into account is complex 23013 especially for modern RISC processors. 23014 23015 The task of exploiting more processor parallelism is solved by an 23016 instruction scheduler. For a better solution to this problem, the 23017 instruction scheduler has to have an adequate description of the 23018 processor parallelism (or "pipeline description"). GCC machine 23019 descriptions describe processor parallelism and functional unit 23020 reservations for groups of instructions with the aid of "regular 23021 expressions". 23022 23023 The GCC instruction scheduler uses a "pipeline hazard recognizer" to 23024 figure out the possibility of the instruction issue by the processor on 23025 a given simulated processor cycle. The pipeline hazard recognizer is 23026 automatically generated from the processor pipeline description. The 23027 pipeline hazard recognizer generated from the machine description is 23028 based on a deterministic finite state automaton (DFA): the instruction 23029 issue is possible if there is a transition from one automaton state to 23030 another one. This algorithm is very fast, and furthermore, its speed 23031 is not dependent on processor complexity(1). 23032 23033 The rest of this section describes the directives that constitute an 23034 automaton-based processor pipeline description. The order of these 23035 constructions within the machine description file is not important. 23036 23037 The following optional construction describes names of automata 23038 generated and used for the pipeline hazards recognition. Sometimes the 23039 generated finite state automaton used by the pipeline hazard recognizer 23040 is large. If we use more than one automaton and bind functional units 23041 to the automata, the total size of the automata is usually less than 23042 the size of the single automaton. If there is no one such 23043 construction, only one finite state automaton is generated. 23044 23045 (define_automaton AUTOMATA-NAMES) 23046 23047 AUTOMATA-NAMES is a string giving names of the automata. The names 23048 are separated by commas. All the automata should have unique names. 23049 The automaton name is used in the constructions `define_cpu_unit' and 23050 `define_query_cpu_unit'. 23051 23052 Each processor functional unit used in the description of instruction 23053 reservations should be described by the following construction. 23054 23055 (define_cpu_unit UNIT-NAMES [AUTOMATON-NAME]) 23056 23057 UNIT-NAMES is a string giving the names of the functional units 23058 separated by commas. Don't use name `nothing', it is reserved for 23059 other goals. 23060 23061 AUTOMATON-NAME is a string giving the name of the automaton with which 23062 the unit is bound. The automaton should be described in construction 23063 `define_automaton'. You should give "automaton-name", if there is a 23064 defined automaton. 23065 23066 The assignment of units to automata are constrained by the uses of the 23067 units in insn reservations. The most important constraint is: if a 23068 unit reservation is present on a particular cycle of an alternative for 23069 an insn reservation, then some unit from the same automaton must be 23070 present on the same cycle for the other alternatives of the insn 23071 reservation. The rest of the constraints are mentioned in the 23072 description of the subsequent constructions. 23073 23074 The following construction describes CPU functional units analogously 23075 to `define_cpu_unit'. The reservation of such units can be queried for 23076 an automaton state. The instruction scheduler never queries 23077 reservation of functional units for given automaton state. So as a 23078 rule, you don't need this construction. This construction could be 23079 used for future code generation goals (e.g. to generate VLIW insn 23080 templates). 23081 23082 (define_query_cpu_unit UNIT-NAMES [AUTOMATON-NAME]) 23083 23084 UNIT-NAMES is a string giving names of the functional units separated 23085 by commas. 23086 23087 AUTOMATON-NAME is a string giving the name of the automaton with which 23088 the unit is bound. 23089 23090 The following construction is the major one to describe pipeline 23091 characteristics of an instruction. 23092 23093 (define_insn_reservation INSN-NAME DEFAULT_LATENCY 23094 CONDITION REGEXP) 23095 23096 DEFAULT_LATENCY is a number giving latency time of the instruction. 23097 There is an important difference between the old description and the 23098 automaton based pipeline description. The latency time is used for all 23099 dependencies when we use the old description. In the automaton based 23100 pipeline description, the given latency time is only used for true 23101 dependencies. The cost of anti-dependencies is always zero and the 23102 cost of output dependencies is the difference between latency times of 23103 the producing and consuming insns (if the difference is negative, the 23104 cost is considered to be zero). You can always change the default 23105 costs for any description by using the target hook 23106 `TARGET_SCHED_ADJUST_COST' (*note Scheduling::). 23107 23108 INSN-NAME is a string giving the internal name of the insn. The 23109 internal names are used in constructions `define_bypass' and in the 23110 automaton description file generated for debugging. The internal name 23111 has nothing in common with the names in `define_insn'. It is a good 23112 practice to use insn classes described in the processor manual. 23113 23114 CONDITION defines what RTL insns are described by this construction. 23115 You should remember that you will be in trouble if CONDITION for two or 23116 more different `define_insn_reservation' constructions is TRUE for an 23117 insn. In this case what reservation will be used for the insn is not 23118 defined. Such cases are not checked during generation of the pipeline 23119 hazards recognizer because in general recognizing that two conditions 23120 may have the same value is quite difficult (especially if the conditions 23121 contain `symbol_ref'). It is also not checked during the pipeline 23122 hazard recognizer work because it would slow down the recognizer 23123 considerably. 23124 23125 REGEXP is a string describing the reservation of the cpu's functional 23126 units by the instruction. The reservations are described by a regular 23127 expression according to the following syntax: 23128 23129 regexp = regexp "," oneof 23130 | oneof 23131 23132 oneof = oneof "|" allof 23133 | allof 23134 23135 allof = allof "+" repeat 23136 | repeat 23137 23138 repeat = element "*" number 23139 | element 23140 23141 element = cpu_function_unit_name 23142 | reservation_name 23143 | result_name 23144 | "nothing" 23145 | "(" regexp ")" 23146 23147 * `,' is used for describing the start of the next cycle in the 23148 reservation. 23149 23150 * `|' is used for describing a reservation described by the first 23151 regular expression *or* a reservation described by the second 23152 regular expression *or* etc. 23153 23154 * `+' is used for describing a reservation described by the first 23155 regular expression *and* a reservation described by the second 23156 regular expression *and* etc. 23157 23158 * `*' is used for convenience and simply means a sequence in which 23159 the regular expression are repeated NUMBER times with cycle 23160 advancing (see `,'). 23161 23162 * `cpu_function_unit_name' denotes reservation of the named 23163 functional unit. 23164 23165 * `reservation_name' -- see description of construction 23166 `define_reservation'. 23167 23168 * `nothing' denotes no unit reservations. 23169 23170 Sometimes unit reservations for different insns contain common parts. 23171 In such case, you can simplify the pipeline description by describing 23172 the common part by the following construction 23173 23174 (define_reservation RESERVATION-NAME REGEXP) 23175 23176 RESERVATION-NAME is a string giving name of REGEXP. Functional unit 23177 names and reservation names are in the same name space. So the 23178 reservation names should be different from the functional unit names 23179 and can not be the reserved name `nothing'. 23180 23181 The following construction is used to describe exceptions in the 23182 latency time for given instruction pair. This is so called bypasses. 23183 23184 (define_bypass NUMBER OUT_INSN_NAMES IN_INSN_NAMES 23185 [GUARD]) 23186 23187 NUMBER defines when the result generated by the instructions given in 23188 string OUT_INSN_NAMES will be ready for the instructions given in 23189 string IN_INSN_NAMES. The instructions in the string are separated by 23190 commas. 23191 23192 GUARD is an optional string giving the name of a C function which 23193 defines an additional guard for the bypass. The function will get the 23194 two insns as parameters. If the function returns zero the bypass will 23195 be ignored for this case. The additional guard is necessary to 23196 recognize complicated bypasses, e.g. when the consumer is only an 23197 address of insn `store' (not a stored value). 23198 23199 The following five constructions are usually used to describe VLIW 23200 processors, or more precisely, to describe a placement of small 23201 instructions into VLIW instruction slots. They can be used for RISC 23202 processors, too. 23203 23204 (exclusion_set UNIT-NAMES UNIT-NAMES) 23205 (presence_set UNIT-NAMES PATTERNS) 23206 (final_presence_set UNIT-NAMES PATTERNS) 23207 (absence_set UNIT-NAMES PATTERNS) 23208 (final_absence_set UNIT-NAMES PATTERNS) 23209 23210 UNIT-NAMES is a string giving names of functional units separated by 23211 commas. 23212 23213 PATTERNS is a string giving patterns of functional units separated by 23214 comma. Currently pattern is one unit or units separated by 23215 white-spaces. 23216 23217 The first construction (`exclusion_set') means that each functional 23218 unit in the first string can not be reserved simultaneously with a unit 23219 whose name is in the second string and vice versa. For example, the 23220 construction is useful for describing processors (e.g. some SPARC 23221 processors) with a fully pipelined floating point functional unit which 23222 can execute simultaneously only single floating point insns or only 23223 double floating point insns. 23224 23225 The second construction (`presence_set') means that each functional 23226 unit in the first string can not be reserved unless at least one of 23227 pattern of units whose names are in the second string is reserved. 23228 This is an asymmetric relation. For example, it is useful for 23229 description that VLIW `slot1' is reserved after `slot0' reservation. 23230 We could describe it by the following construction 23231 23232 (presence_set "slot1" "slot0") 23233 23234 Or `slot1' is reserved only after `slot0' and unit `b0' reservation. 23235 In this case we could write 23236 23237 (presence_set "slot1" "slot0 b0") 23238 23239 The third construction (`final_presence_set') is analogous to 23240 `presence_set'. The difference between them is when checking is done. 23241 When an instruction is issued in given automaton state reflecting all 23242 current and planned unit reservations, the automaton state is changed. 23243 The first state is a source state, the second one is a result state. 23244 Checking for `presence_set' is done on the source state reservation, 23245 checking for `final_presence_set' is done on the result reservation. 23246 This construction is useful to describe a reservation which is actually 23247 two subsequent reservations. For example, if we use 23248 23249 (presence_set "slot1" "slot0") 23250 23251 the following insn will be never issued (because `slot1' requires 23252 `slot0' which is absent in the source state). 23253 23254 (define_reservation "insn_and_nop" "slot0 + slot1") 23255 23256 but it can be issued if we use analogous `final_presence_set'. 23257 23258 The forth construction (`absence_set') means that each functional unit 23259 in the first string can be reserved only if each pattern of units whose 23260 names are in the second string is not reserved. This is an asymmetric 23261 relation (actually `exclusion_set' is analogous to this one but it is 23262 symmetric). For example it might be useful in a VLIW description to 23263 say that `slot0' cannot be reserved after either `slot1' or `slot2' 23264 have been reserved. This can be described as: 23265 23266 (absence_set "slot0" "slot1, slot2") 23267 23268 Or `slot2' can not be reserved if `slot0' and unit `b0' are reserved 23269 or `slot1' and unit `b1' are reserved. In this case we could write 23270 23271 (absence_set "slot2" "slot0 b0, slot1 b1") 23272 23273 All functional units mentioned in a set should belong to the same 23274 automaton. 23275 23276 The last construction (`final_absence_set') is analogous to 23277 `absence_set' but checking is done on the result (state) reservation. 23278 See comments for `final_presence_set'. 23279 23280 You can control the generator of the pipeline hazard recognizer with 23281 the following construction. 23282 23283 (automata_option OPTIONS) 23284 23285 OPTIONS is a string giving options which affect the generated code. 23286 Currently there are the following options: 23287 23288 * "no-minimization" makes no minimization of the automaton. This is 23289 only worth to do when we are debugging the description and need to 23290 look more accurately at reservations of states. 23291 23292 * "time" means printing time statistics about the generation of 23293 automata. 23294 23295 * "stats" means printing statistics about the generated automata 23296 such as the number of DFA states, NDFA states and arcs. 23297 23298 * "v" means a generation of the file describing the result automata. 23299 The file has suffix `.dfa' and can be used for the description 23300 verification and debugging. 23301 23302 * "w" means a generation of warning instead of error for 23303 non-critical errors. 23304 23305 * "ndfa" makes nondeterministic finite state automata. This affects 23306 the treatment of operator `|' in the regular expressions. The 23307 usual treatment of the operator is to try the first alternative 23308 and, if the reservation is not possible, the second alternative. 23309 The nondeterministic treatment means trying all alternatives, some 23310 of them may be rejected by reservations in the subsequent insns. 23311 23312 * "progress" means output of a progress bar showing how many states 23313 were generated so far for automaton being processed. This is 23314 useful during debugging a DFA description. If you see too many 23315 generated states, you could interrupt the generator of the pipeline 23316 hazard recognizer and try to figure out a reason for generation of 23317 the huge automaton. 23318 23319 As an example, consider a superscalar RISC machine which can issue 23320 three insns (two integer insns and one floating point insn) on the 23321 cycle but can finish only two insns. To describe this, we define the 23322 following functional units. 23323 23324 (define_cpu_unit "i0_pipeline, i1_pipeline, f_pipeline") 23325 (define_cpu_unit "port0, port1") 23326 23327 All simple integer insns can be executed in any integer pipeline and 23328 their result is ready in two cycles. The simple integer insns are 23329 issued into the first pipeline unless it is reserved, otherwise they 23330 are issued into the second pipeline. Integer division and 23331 multiplication insns can be executed only in the second integer 23332 pipeline and their results are ready correspondingly in 8 and 4 cycles. 23333 The integer division is not pipelined, i.e. the subsequent integer 23334 division insn can not be issued until the current division insn 23335 finished. Floating point insns are fully pipelined and their results 23336 are ready in 3 cycles. Where the result of a floating point insn is 23337 used by an integer insn, an additional delay of one cycle is incurred. 23338 To describe all of this we could specify 23339 23340 (define_cpu_unit "div") 23341 23342 (define_insn_reservation "simple" 2 (eq_attr "type" "int") 23343 "(i0_pipeline | i1_pipeline), (port0 | port1)") 23344 23345 (define_insn_reservation "mult" 4 (eq_attr "type" "mult") 23346 "i1_pipeline, nothing*2, (port0 | port1)") 23347 23348 (define_insn_reservation "div" 8 (eq_attr "type" "div") 23349 "i1_pipeline, div*7, div + (port0 | port1)") 23350 23351 (define_insn_reservation "float" 3 (eq_attr "type" "float") 23352 "f_pipeline, nothing, (port0 | port1)) 23353 23354 (define_bypass 4 "float" "simple,mult,div") 23355 23356 To simplify the description we could describe the following reservation 23357 23358 (define_reservation "finish" "port0|port1") 23359 23360 and use it in all `define_insn_reservation' as in the following 23361 construction 23362 23363 (define_insn_reservation "simple" 2 (eq_attr "type" "int") 23364 "(i0_pipeline | i1_pipeline), finish") 23365 23366 ---------- Footnotes ---------- 23367 23368 (1) However, the size of the automaton depends on processor 23369 complexity. To limit this effect, machine descriptions can split 23370 orthogonal parts of the machine description among several automata: but 23371 then, since each of these must be stepped independently, this does 23372 cause a small decrease in the algorithm's performance. 23373 23374 23375 File: gccint.info, Node: Conditional Execution, Next: Constant Definitions, Prev: Insn Attributes, Up: Machine Desc 23376 23377 16.20 Conditional Execution 23378 =========================== 23379 23380 A number of architectures provide for some form of conditional 23381 execution, or predication. The hallmark of this feature is the ability 23382 to nullify most of the instructions in the instruction set. When the 23383 instruction set is large and not entirely symmetric, it can be quite 23384 tedious to describe these forms directly in the `.md' file. An 23385 alternative is the `define_cond_exec' template. 23386 23387 (define_cond_exec 23388 [PREDICATE-PATTERN] 23389 "CONDITION" 23390 "OUTPUT-TEMPLATE") 23391 23392 PREDICATE-PATTERN is the condition that must be true for the insn to 23393 be executed at runtime and should match a relational operator. One can 23394 use `match_operator' to match several relational operators at once. 23395 Any `match_operand' operands must have no more than one alternative. 23396 23397 CONDITION is a C expression that must be true for the generated 23398 pattern to match. 23399 23400 OUTPUT-TEMPLATE is a string similar to the `define_insn' output 23401 template (*note Output Template::), except that the `*' and `@' special 23402 cases do not apply. This is only useful if the assembly text for the 23403 predicate is a simple prefix to the main insn. In order to handle the 23404 general case, there is a global variable `current_insn_predicate' that 23405 will contain the entire predicate if the current insn is predicated, 23406 and will otherwise be `NULL'. 23407 23408 When `define_cond_exec' is used, an implicit reference to the 23409 `predicable' instruction attribute is made. *Note Insn Attributes::. 23410 This attribute must be boolean (i.e. have exactly two elements in its 23411 LIST-OF-VALUES). Further, it must not be used with complex 23412 expressions. That is, the default and all uses in the insns must be a 23413 simple constant, not dependent on the alternative or anything else. 23414 23415 For each `define_insn' for which the `predicable' attribute is true, a 23416 new `define_insn' pattern will be generated that matches a predicated 23417 version of the instruction. For example, 23418 23419 (define_insn "addsi" 23420 [(set (match_operand:SI 0 "register_operand" "r") 23421 (plus:SI (match_operand:SI 1 "register_operand" "r") 23422 (match_operand:SI 2 "register_operand" "r")))] 23423 "TEST1" 23424 "add %2,%1,%0") 23425 23426 (define_cond_exec 23427 [(ne (match_operand:CC 0 "register_operand" "c") 23428 (const_int 0))] 23429 "TEST2" 23430 "(%0)") 23431 23432 generates a new pattern 23433 23434 (define_insn "" 23435 [(cond_exec 23436 (ne (match_operand:CC 3 "register_operand" "c") (const_int 0)) 23437 (set (match_operand:SI 0 "register_operand" "r") 23438 (plus:SI (match_operand:SI 1 "register_operand" "r") 23439 (match_operand:SI 2 "register_operand" "r"))))] 23440 "(TEST2) && (TEST1)" 23441 "(%3) add %2,%1,%0") 23442 23443 23444 File: gccint.info, Node: Constant Definitions, Next: Iterators, Prev: Conditional Execution, Up: Machine Desc 23445 23446 16.21 Constant Definitions 23447 ========================== 23448 23449 Using literal constants inside instruction patterns reduces legibility 23450 and can be a maintenance problem. 23451 23452 To overcome this problem, you may use the `define_constants' 23453 expression. It contains a vector of name-value pairs. From that point 23454 on, wherever any of the names appears in the MD file, it is as if the 23455 corresponding value had been written instead. You may use 23456 `define_constants' multiple times; each appearance adds more constants 23457 to the table. It is an error to redefine a constant with a different 23458 value. 23459 23460 To come back to the a29k load multiple example, instead of 23461 23462 (define_insn "" 23463 [(match_parallel 0 "load_multiple_operation" 23464 [(set (match_operand:SI 1 "gpc_reg_operand" "=r") 23465 (match_operand:SI 2 "memory_operand" "m")) 23466 (use (reg:SI 179)) 23467 (clobber (reg:SI 179))])] 23468 "" 23469 "loadm 0,0,%1,%2") 23470 23471 You could write: 23472 23473 (define_constants [ 23474 (R_BP 177) 23475 (R_FC 178) 23476 (R_CR 179) 23477 (R_Q 180) 23478 ]) 23479 23480 (define_insn "" 23481 [(match_parallel 0 "load_multiple_operation" 23482 [(set (match_operand:SI 1 "gpc_reg_operand" "=r") 23483 (match_operand:SI 2 "memory_operand" "m")) 23484 (use (reg:SI R_CR)) 23485 (clobber (reg:SI R_CR))])] 23486 "" 23487 "loadm 0,0,%1,%2") 23488 23489 The constants that are defined with a define_constant are also output 23490 in the insn-codes.h header file as #defines. 23491 23492 23493 File: gccint.info, Node: Iterators, Prev: Constant Definitions, Up: Machine Desc 23494 23495 16.22 Iterators 23496 =============== 23497 23498 Ports often need to define similar patterns for more than one machine 23499 mode or for more than one rtx code. GCC provides some simple iterator 23500 facilities to make this process easier. 23501 23502 * Menu: 23503 23504 * Mode Iterators:: Generating variations of patterns for different modes. 23505 * Code Iterators:: Doing the same for codes. 23506 23507 23508 File: gccint.info, Node: Mode Iterators, Next: Code Iterators, Up: Iterators 23509 23510 16.22.1 Mode Iterators 23511 ---------------------- 23512 23513 Ports often need to define similar patterns for two or more different 23514 modes. For example: 23515 23516 * If a processor has hardware support for both single and double 23517 floating-point arithmetic, the `SFmode' patterns tend to be very 23518 similar to the `DFmode' ones. 23519 23520 * If a port uses `SImode' pointers in one configuration and `DImode' 23521 pointers in another, it will usually have very similar `SImode' 23522 and `DImode' patterns for manipulating pointers. 23523 23524 Mode iterators allow several patterns to be instantiated from one 23525 `.md' file template. They can be used with any type of rtx-based 23526 construct, such as a `define_insn', `define_split', or 23527 `define_peephole2'. 23528 23529 * Menu: 23530 23531 * Defining Mode Iterators:: Defining a new mode iterator. 23532 * Substitutions:: Combining mode iterators with substitutions 23533 * Examples:: Examples 23534 23535 23536 File: gccint.info, Node: Defining Mode Iterators, Next: Substitutions, Up: Mode Iterators 23537 23538 16.22.1.1 Defining Mode Iterators 23539 ................................. 23540 23541 The syntax for defining a mode iterator is: 23542 23543 (define_mode_iterator NAME [(MODE1 "COND1") ... (MODEN "CONDN")]) 23544 23545 This allows subsequent `.md' file constructs to use the mode suffix 23546 `:NAME'. Every construct that does so will be expanded N times, once 23547 with every use of `:NAME' replaced by `:MODE1', once with every use 23548 replaced by `:MODE2', and so on. In the expansion for a particular 23549 MODEI, every C condition will also require that CONDI be true. 23550 23551 For example: 23552 23553 (define_mode_iterator P [(SI "Pmode == SImode") (DI "Pmode == DImode")]) 23554 23555 defines a new mode suffix `:P'. Every construct that uses `:P' will 23556 be expanded twice, once with every `:P' replaced by `:SI' and once with 23557 every `:P' replaced by `:DI'. The `:SI' version will only apply if 23558 `Pmode == SImode' and the `:DI' version will only apply if `Pmode == 23559 DImode'. 23560 23561 As with other `.md' conditions, an empty string is treated as "always 23562 true". `(MODE "")' can also be abbreviated to `MODE'. For example: 23563 23564 (define_mode_iterator GPR [SI (DI "TARGET_64BIT")]) 23565 23566 means that the `:DI' expansion only applies if `TARGET_64BIT' but that 23567 the `:SI' expansion has no such constraint. 23568 23569 Iterators are applied in the order they are defined. This can be 23570 significant if two iterators are used in a construct that requires 23571 substitutions. *Note Substitutions::. 23572 23573 23574 File: gccint.info, Node: Substitutions, Next: Examples, Prev: Defining Mode Iterators, Up: Mode Iterators 23575 23576 16.22.1.2 Substitution in Mode Iterators 23577 ........................................ 23578 23579 If an `.md' file construct uses mode iterators, each version of the 23580 construct will often need slightly different strings or modes. For 23581 example: 23582 23583 * When a `define_expand' defines several `addM3' patterns (*note 23584 Standard Names::), each expander will need to use the appropriate 23585 mode name for M. 23586 23587 * When a `define_insn' defines several instruction patterns, each 23588 instruction will often use a different assembler mnemonic. 23589 23590 * When a `define_insn' requires operands with different modes, using 23591 an iterator for one of the operand modes usually requires a 23592 specific mode for the other operand(s). 23593 23594 GCC supports such variations through a system of "mode attributes". 23595 There are two standard attributes: `mode', which is the name of the 23596 mode in lower case, and `MODE', which is the same thing in upper case. 23597 You can define other attributes using: 23598 23599 (define_mode_attr NAME [(MODE1 "VALUE1") ... (MODEN "VALUEN")]) 23600 23601 where NAME is the name of the attribute and VALUEI is the value 23602 associated with MODEI. 23603 23604 When GCC replaces some :ITERATOR with :MODE, it will scan each string 23605 and mode in the pattern for sequences of the form `<ITERATOR:ATTR>', 23606 where ATTR is the name of a mode attribute. If the attribute is 23607 defined for MODE, the whole `<...>' sequence will be replaced by the 23608 appropriate attribute value. 23609 23610 For example, suppose an `.md' file has: 23611 23612 (define_mode_iterator P [(SI "Pmode == SImode") (DI "Pmode == DImode")]) 23613 (define_mode_attr load [(SI "lw") (DI "ld")]) 23614 23615 If one of the patterns that uses `:P' contains the string 23616 `"<P:load>\t%0,%1"', the `SI' version of that pattern will use 23617 `"lw\t%0,%1"' and the `DI' version will use `"ld\t%0,%1"'. 23618 23619 Here is an example of using an attribute for a mode: 23620 23621 (define_mode_iterator LONG [SI DI]) 23622 (define_mode_attr SHORT [(SI "HI") (DI "SI")]) 23623 (define_insn ... 23624 (sign_extend:LONG (match_operand:<LONG:SHORT> ...)) ...) 23625 23626 The `ITERATOR:' prefix may be omitted, in which case the substitution 23627 will be attempted for every iterator expansion. 23628 23629 23630 File: gccint.info, Node: Examples, Prev: Substitutions, Up: Mode Iterators 23631 23632 16.22.1.3 Mode Iterator Examples 23633 ................................ 23634 23635 Here is an example from the MIPS port. It defines the following modes 23636 and attributes (among others): 23637 23638 (define_mode_iterator GPR [SI (DI "TARGET_64BIT")]) 23639 (define_mode_attr d [(SI "") (DI "d")]) 23640 23641 and uses the following template to define both `subsi3' and `subdi3': 23642 23643 (define_insn "sub<mode>3" 23644 [(set (match_operand:GPR 0 "register_operand" "=d") 23645 (minus:GPR (match_operand:GPR 1 "register_operand" "d") 23646 (match_operand:GPR 2 "register_operand" "d")))] 23647 "" 23648 "<d>subu\t%0,%1,%2" 23649 [(set_attr "type" "arith") 23650 (set_attr "mode" "<MODE>")]) 23651 23652 This is exactly equivalent to: 23653 23654 (define_insn "subsi3" 23655 [(set (match_operand:SI 0 "register_operand" "=d") 23656 (minus:SI (match_operand:SI 1 "register_operand" "d") 23657 (match_operand:SI 2 "register_operand" "d")))] 23658 "" 23659 "subu\t%0,%1,%2" 23660 [(set_attr "type" "arith") 23661 (set_attr "mode" "SI")]) 23662 23663 (define_insn "subdi3" 23664 [(set (match_operand:DI 0 "register_operand" "=d") 23665 (minus:DI (match_operand:DI 1 "register_operand" "d") 23666 (match_operand:DI 2 "register_operand" "d")))] 23667 "" 23668 "dsubu\t%0,%1,%2" 23669 [(set_attr "type" "arith") 23670 (set_attr "mode" "DI")]) 23671 23672 23673 File: gccint.info, Node: Code Iterators, Prev: Mode Iterators, Up: Iterators 23674 23675 16.22.2 Code Iterators 23676 ---------------------- 23677 23678 Code iterators operate in a similar way to mode iterators. *Note Mode 23679 Iterators::. 23680 23681 The construct: 23682 23683 (define_code_iterator NAME [(CODE1 "COND1") ... (CODEN "CONDN")]) 23684 23685 defines a pseudo rtx code NAME that can be instantiated as CODEI if 23686 condition CONDI is true. Each CODEI must have the same rtx format. 23687 *Note RTL Classes::. 23688 23689 As with mode iterators, each pattern that uses NAME will be expanded N 23690 times, once with all uses of NAME replaced by CODE1, once with all uses 23691 replaced by CODE2, and so on. *Note Defining Mode Iterators::. 23692 23693 It is possible to define attributes for codes as well as for modes. 23694 There are two standard code attributes: `code', the name of the code in 23695 lower case, and `CODE', the name of the code in upper case. Other 23696 attributes are defined using: 23697 23698 (define_code_attr NAME [(CODE1 "VALUE1") ... (CODEN "VALUEN")]) 23699 23700 Here's an example of code iterators in action, taken from the MIPS 23701 port: 23702 23703 (define_code_iterator any_cond [unordered ordered unlt unge uneq ltgt unle ungt 23704 eq ne gt ge lt le gtu geu ltu leu]) 23705 23706 (define_expand "b<code>" 23707 [(set (pc) 23708 (if_then_else (any_cond:CC (cc0) 23709 (const_int 0)) 23710 (label_ref (match_operand 0 "")) 23711 (pc)))] 23712 "" 23713 { 23714 gen_conditional_branch (operands, <CODE>); 23715 DONE; 23716 }) 23717 23718 This is equivalent to: 23719 23720 (define_expand "bunordered" 23721 [(set (pc) 23722 (if_then_else (unordered:CC (cc0) 23723 (const_int 0)) 23724 (label_ref (match_operand 0 "")) 23725 (pc)))] 23726 "" 23727 { 23728 gen_conditional_branch (operands, UNORDERED); 23729 DONE; 23730 }) 23731 23732 (define_expand "bordered" 23733 [(set (pc) 23734 (if_then_else (ordered:CC (cc0) 23735 (const_int 0)) 23736 (label_ref (match_operand 0 "")) 23737 (pc)))] 23738 "" 23739 { 23740 gen_conditional_branch (operands, ORDERED); 23741 DONE; 23742 }) 23743 23744 ... 23745 23746 23747 File: gccint.info, Node: Target Macros, Next: Host Config, Prev: Machine Desc, Up: Top 23748 23749 17 Target Description Macros and Functions 23750 ****************************************** 23751 23752 In addition to the file `MACHINE.md', a machine description includes a 23753 C header file conventionally given the name `MACHINE.h' and a C source 23754 file named `MACHINE.c'. The header file defines numerous macros that 23755 convey the information about the target machine that does not fit into 23756 the scheme of the `.md' file. The file `tm.h' should be a link to 23757 `MACHINE.h'. The header file `config.h' includes `tm.h' and most 23758 compiler source files include `config.h'. The source file defines a 23759 variable `targetm', which is a structure containing pointers to 23760 functions and data relating to the target machine. `MACHINE.c' should 23761 also contain their definitions, if they are not defined elsewhere in 23762 GCC, and other functions called through the macros defined in the `.h' 23763 file. 23764 23765 * Menu: 23766 23767 * Target Structure:: The `targetm' variable. 23768 * Driver:: Controlling how the driver runs the compilation passes. 23769 * Run-time Target:: Defining `-m' options like `-m68000' and `-m68020'. 23770 * Per-Function Data:: Defining data structures for per-function information. 23771 * Storage Layout:: Defining sizes and alignments of data. 23772 * Type Layout:: Defining sizes and properties of basic user data types. 23773 * Registers:: Naming and describing the hardware registers. 23774 * Register Classes:: Defining the classes of hardware registers. 23775 * Old Constraints:: The old way to define machine-specific constraints. 23776 * Stack and Calling:: Defining which way the stack grows and by how much. 23777 * Varargs:: Defining the varargs macros. 23778 * Trampolines:: Code set up at run time to enter a nested function. 23779 * Library Calls:: Controlling how library routines are implicitly called. 23780 * Addressing Modes:: Defining addressing modes valid for memory operands. 23781 * Anchored Addresses:: Defining how `-fsection-anchors' should work. 23782 * Condition Code:: Defining how insns update the condition code. 23783 * Costs:: Defining relative costs of different operations. 23784 * Scheduling:: Adjusting the behavior of the instruction scheduler. 23785 * Sections:: Dividing storage into text, data, and other sections. 23786 * PIC:: Macros for position independent code. 23787 * Assembler Format:: Defining how to write insns and pseudo-ops to output. 23788 * Debugging Info:: Defining the format of debugging output. 23789 * Floating Point:: Handling floating point for cross-compilers. 23790 * Mode Switching:: Insertion of mode-switching instructions. 23791 * Target Attributes:: Defining target-specific uses of `__attribute__'. 23792 * Emulated TLS:: Emulated TLS support. 23793 * MIPS Coprocessors:: MIPS coprocessor support and how to customize it. 23794 * PCH Target:: Validity checking for precompiled headers. 23795 * C++ ABI:: Controlling C++ ABI changes. 23796 * Misc:: Everything else. 23797 23798 23799 File: gccint.info, Node: Target Structure, Next: Driver, Up: Target Macros 23800 23801 17.1 The Global `targetm' Variable 23802 ================================== 23803 23804 -- Variable: struct gcc_target targetm 23805 The target `.c' file must define the global `targetm' variable 23806 which contains pointers to functions and data relating to the 23807 target machine. The variable is declared in `target.h'; 23808 `target-def.h' defines the macro `TARGET_INITIALIZER' which is 23809 used to initialize the variable, and macros for the default 23810 initializers for elements of the structure. The `.c' file should 23811 override those macros for which the default definition is 23812 inappropriate. For example: 23813 #include "target.h" 23814 #include "target-def.h" 23815 23816 /* Initialize the GCC target structure. */ 23817 23818 #undef TARGET_COMP_TYPE_ATTRIBUTES 23819 #define TARGET_COMP_TYPE_ATTRIBUTES MACHINE_comp_type_attributes 23820 23821 struct gcc_target targetm = TARGET_INITIALIZER; 23822 23823 Where a macro should be defined in the `.c' file in this manner to form 23824 part of the `targetm' structure, it is documented below as a "Target 23825 Hook" with a prototype. Many macros will change in future from being 23826 defined in the `.h' file to being part of the `targetm' structure. 23827 23828 23829 File: gccint.info, Node: Driver, Next: Run-time Target, Prev: Target Structure, Up: Target Macros 23830 23831 17.2 Controlling the Compilation Driver, `gcc' 23832 ============================================== 23833 23834 You can control the compilation driver. 23835 23836 -- Macro: SWITCH_TAKES_ARG (CHAR) 23837 A C expression which determines whether the option `-CHAR' takes 23838 arguments. The value should be the number of arguments that 23839 option takes-zero, for many options. 23840 23841 By default, this macro is defined as `DEFAULT_SWITCH_TAKES_ARG', 23842 which handles the standard options properly. You need not define 23843 `SWITCH_TAKES_ARG' unless you wish to add additional options which 23844 take arguments. Any redefinition should call 23845 `DEFAULT_SWITCH_TAKES_ARG' and then check for additional options. 23846 23847 -- Macro: WORD_SWITCH_TAKES_ARG (NAME) 23848 A C expression which determines whether the option `-NAME' takes 23849 arguments. The value should be the number of arguments that 23850 option takes-zero, for many options. This macro rather than 23851 `SWITCH_TAKES_ARG' is used for multi-character option names. 23852 23853 By default, this macro is defined as 23854 `DEFAULT_WORD_SWITCH_TAKES_ARG', which handles the standard options 23855 properly. You need not define `WORD_SWITCH_TAKES_ARG' unless you 23856 wish to add additional options which take arguments. Any 23857 redefinition should call `DEFAULT_WORD_SWITCH_TAKES_ARG' and then 23858 check for additional options. 23859 23860 -- Macro: SWITCH_CURTAILS_COMPILATION (CHAR) 23861 A C expression which determines whether the option `-CHAR' stops 23862 compilation before the generation of an executable. The value is 23863 boolean, nonzero if the option does stop an executable from being 23864 generated, zero otherwise. 23865 23866 By default, this macro is defined as 23867 `DEFAULT_SWITCH_CURTAILS_COMPILATION', which handles the standard 23868 options properly. You need not define 23869 `SWITCH_CURTAILS_COMPILATION' unless you wish to add additional 23870 options which affect the generation of an executable. Any 23871 redefinition should call `DEFAULT_SWITCH_CURTAILS_COMPILATION' and 23872 then check for additional options. 23873 23874 -- Macro: SWITCHES_NEED_SPACES 23875 A string-valued C expression which enumerates the options for which 23876 the linker needs a space between the option and its argument. 23877 23878 If this macro is not defined, the default value is `""'. 23879 23880 -- Macro: TARGET_OPTION_TRANSLATE_TABLE 23881 If defined, a list of pairs of strings, the first of which is a 23882 potential command line target to the `gcc' driver program, and the 23883 second of which is a space-separated (tabs and other whitespace 23884 are not supported) list of options with which to replace the first 23885 option. The target defining this list is responsible for assuring 23886 that the results are valid. Replacement options may not be the 23887 `--opt' style, they must be the `-opt' style. It is the intention 23888 of this macro to provide a mechanism for substitution that affects 23889 the multilibs chosen, such as one option that enables many 23890 options, some of which select multilibs. Example nonsensical 23891 definition, where `-malt-abi', `-EB', and `-mspoo' cause different 23892 multilibs to be chosen: 23893 23894 #define TARGET_OPTION_TRANSLATE_TABLE \ 23895 { "-fast", "-march=fast-foo -malt-abi -I/usr/fast-foo" }, \ 23896 { "-compat", "-EB -malign=4 -mspoo" } 23897 23898 -- Macro: DRIVER_SELF_SPECS 23899 A list of specs for the driver itself. It should be a suitable 23900 initializer for an array of strings, with no surrounding braces. 23901 23902 The driver applies these specs to its own command line between 23903 loading default `specs' files (but not command-line specified 23904 ones) and choosing the multilib directory or running any 23905 subcommands. It applies them in the order given, so each spec can 23906 depend on the options added by earlier ones. It is also possible 23907 to remove options using `%<OPTION' in the usual way. 23908 23909 This macro can be useful when a port has several interdependent 23910 target options. It provides a way of standardizing the command 23911 line so that the other specs are easier to write. 23912 23913 Do not define this macro if it does not need to do anything. 23914 23915 -- Macro: OPTION_DEFAULT_SPECS 23916 A list of specs used to support configure-time default options 23917 (i.e. `--with' options) in the driver. It should be a suitable 23918 initializer for an array of structures, each containing two 23919 strings, without the outermost pair of surrounding braces. 23920 23921 The first item in the pair is the name of the default. This must 23922 match the code in `config.gcc' for the target. The second item is 23923 a spec to apply if a default with this name was specified. The 23924 string `%(VALUE)' in the spec will be replaced by the value of the 23925 default everywhere it occurs. 23926 23927 The driver will apply these specs to its own command line between 23928 loading default `specs' files and processing `DRIVER_SELF_SPECS', 23929 using the same mechanism as `DRIVER_SELF_SPECS'. 23930 23931 Do not define this macro if it does not need to do anything. 23932 23933 -- Macro: CPP_SPEC 23934 A C string constant that tells the GCC driver program options to 23935 pass to CPP. It can also specify how to translate options you 23936 give to GCC into options for GCC to pass to the CPP. 23937 23938 Do not define this macro if it does not need to do anything. 23939 23940 -- Macro: CPLUSPLUS_CPP_SPEC 23941 This macro is just like `CPP_SPEC', but is used for C++, rather 23942 than C. If you do not define this macro, then the value of 23943 `CPP_SPEC' (if any) will be used instead. 23944 23945 -- Macro: CC1_SPEC 23946 A C string constant that tells the GCC driver program options to 23947 pass to `cc1', `cc1plus', `f771', and the other language front 23948 ends. It can also specify how to translate options you give to 23949 GCC into options for GCC to pass to front ends. 23950 23951 Do not define this macro if it does not need to do anything. 23952 23953 -- Macro: CC1PLUS_SPEC 23954 A C string constant that tells the GCC driver program options to 23955 pass to `cc1plus'. It can also specify how to translate options 23956 you give to GCC into options for GCC to pass to the `cc1plus'. 23957 23958 Do not define this macro if it does not need to do anything. Note 23959 that everything defined in CC1_SPEC is already passed to `cc1plus' 23960 so there is no need to duplicate the contents of CC1_SPEC in 23961 CC1PLUS_SPEC. 23962 23963 -- Macro: ASM_SPEC 23964 A C string constant that tells the GCC driver program options to 23965 pass to the assembler. It can also specify how to translate 23966 options you give to GCC into options for GCC to pass to the 23967 assembler. See the file `sun3.h' for an example of this. 23968 23969 Do not define this macro if it does not need to do anything. 23970 23971 -- Macro: ASM_FINAL_SPEC 23972 A C string constant that tells the GCC driver program how to run 23973 any programs which cleanup after the normal assembler. Normally, 23974 this is not needed. See the file `mips.h' for an example of this. 23975 23976 Do not define this macro if it does not need to do anything. 23977 23978 -- Macro: AS_NEEDS_DASH_FOR_PIPED_INPUT 23979 Define this macro, with no value, if the driver should give the 23980 assembler an argument consisting of a single dash, `-', to 23981 instruct it to read from its standard input (which will be a pipe 23982 connected to the output of the compiler proper). This argument is 23983 given after any `-o' option specifying the name of the output file. 23984 23985 If you do not define this macro, the assembler is assumed to read 23986 its standard input if given no non-option arguments. If your 23987 assembler cannot read standard input at all, use a `%{pipe:%e}' 23988 construct; see `mips.h' for instance. 23989 23990 -- Macro: LINK_SPEC 23991 A C string constant that tells the GCC driver program options to 23992 pass to the linker. It can also specify how to translate options 23993 you give to GCC into options for GCC to pass to the linker. 23994 23995 Do not define this macro if it does not need to do anything. 23996 23997 -- Macro: LIB_SPEC 23998 Another C string constant used much like `LINK_SPEC'. The 23999 difference between the two is that `LIB_SPEC' is used at the end 24000 of the command given to the linker. 24001 24002 If this macro is not defined, a default is provided that loads the 24003 standard C library from the usual place. See `gcc.c'. 24004 24005 -- Macro: LIBGCC_SPEC 24006 Another C string constant that tells the GCC driver program how 24007 and when to place a reference to `libgcc.a' into the linker 24008 command line. This constant is placed both before and after the 24009 value of `LIB_SPEC'. 24010 24011 If this macro is not defined, the GCC driver provides a default 24012 that passes the string `-lgcc' to the linker. 24013 24014 -- Macro: REAL_LIBGCC_SPEC 24015 By default, if `ENABLE_SHARED_LIBGCC' is defined, the 24016 `LIBGCC_SPEC' is not directly used by the driver program but is 24017 instead modified to refer to different versions of `libgcc.a' 24018 depending on the values of the command line flags `-static', 24019 `-shared', `-static-libgcc', and `-shared-libgcc'. On targets 24020 where these modifications are inappropriate, define 24021 `REAL_LIBGCC_SPEC' instead. `REAL_LIBGCC_SPEC' tells the driver 24022 how to place a reference to `libgcc' on the link command line, 24023 but, unlike `LIBGCC_SPEC', it is used unmodified. 24024 24025 -- Macro: USE_LD_AS_NEEDED 24026 A macro that controls the modifications to `LIBGCC_SPEC' mentioned 24027 in `REAL_LIBGCC_SPEC'. If nonzero, a spec will be generated that 24028 uses -as-needed and the shared libgcc in place of the static 24029 exception handler library, when linking without any of `-static', 24030 `-static-libgcc', or `-shared-libgcc'. 24031 24032 -- Macro: LINK_EH_SPEC 24033 If defined, this C string constant is added to `LINK_SPEC'. When 24034 `USE_LD_AS_NEEDED' is zero or undefined, it also affects the 24035 modifications to `LIBGCC_SPEC' mentioned in `REAL_LIBGCC_SPEC'. 24036 24037 -- Macro: STARTFILE_SPEC 24038 Another C string constant used much like `LINK_SPEC'. The 24039 difference between the two is that `STARTFILE_SPEC' is used at the 24040 very beginning of the command given to the linker. 24041 24042 If this macro is not defined, a default is provided that loads the 24043 standard C startup file from the usual place. See `gcc.c'. 24044 24045 -- Macro: ENDFILE_SPEC 24046 Another C string constant used much like `LINK_SPEC'. The 24047 difference between the two is that `ENDFILE_SPEC' is used at the 24048 very end of the command given to the linker. 24049 24050 Do not define this macro if it does not need to do anything. 24051 24052 -- Macro: THREAD_MODEL_SPEC 24053 GCC `-v' will print the thread model GCC was configured to use. 24054 However, this doesn't work on platforms that are multilibbed on 24055 thread models, such as AIX 4.3. On such platforms, define 24056 `THREAD_MODEL_SPEC' such that it evaluates to a string without 24057 blanks that names one of the recognized thread models. `%*', the 24058 default value of this macro, will expand to the value of 24059 `thread_file' set in `config.gcc'. 24060 24061 -- Macro: SYSROOT_SUFFIX_SPEC 24062 Define this macro to add a suffix to the target sysroot when GCC is 24063 configured with a sysroot. This will cause GCC to search for 24064 usr/lib, et al, within sysroot+suffix. 24065 24066 -- Macro: SYSROOT_HEADERS_SUFFIX_SPEC 24067 Define this macro to add a headers_suffix to the target sysroot 24068 when GCC is configured with a sysroot. This will cause GCC to 24069 pass the updated sysroot+headers_suffix to CPP, causing it to 24070 search for usr/include, et al, within sysroot+headers_suffix. 24071 24072 -- Macro: EXTRA_SPECS 24073 Define this macro to provide additional specifications to put in 24074 the `specs' file that can be used in various specifications like 24075 `CC1_SPEC'. 24076 24077 The definition should be an initializer for an array of structures, 24078 containing a string constant, that defines the specification name, 24079 and a string constant that provides the specification. 24080 24081 Do not define this macro if it does not need to do anything. 24082 24083 `EXTRA_SPECS' is useful when an architecture contains several 24084 related targets, which have various `..._SPECS' which are similar 24085 to each other, and the maintainer would like one central place to 24086 keep these definitions. 24087 24088 For example, the PowerPC System V.4 targets use `EXTRA_SPECS' to 24089 define either `_CALL_SYSV' when the System V calling sequence is 24090 used or `_CALL_AIX' when the older AIX-based calling sequence is 24091 used. 24092 24093 The `config/rs6000/rs6000.h' target file defines: 24094 24095 #define EXTRA_SPECS \ 24096 { "cpp_sysv_default", CPP_SYSV_DEFAULT }, 24097 24098 #define CPP_SYS_DEFAULT "" 24099 24100 The `config/rs6000/sysv.h' target file defines: 24101 #undef CPP_SPEC 24102 #define CPP_SPEC \ 24103 "%{posix: -D_POSIX_SOURCE } \ 24104 %{mcall-sysv: -D_CALL_SYSV } \ 24105 %{!mcall-sysv: %(cpp_sysv_default) } \ 24106 %{msoft-float: -D_SOFT_FLOAT} %{mcpu=403: -D_SOFT_FLOAT}" 24107 24108 #undef CPP_SYSV_DEFAULT 24109 #define CPP_SYSV_DEFAULT "-D_CALL_SYSV" 24110 24111 while the `config/rs6000/eabiaix.h' target file defines 24112 `CPP_SYSV_DEFAULT' as: 24113 24114 #undef CPP_SYSV_DEFAULT 24115 #define CPP_SYSV_DEFAULT "-D_CALL_AIX" 24116 24117 -- Macro: LINK_LIBGCC_SPECIAL_1 24118 Define this macro if the driver program should find the library 24119 `libgcc.a'. If you do not define this macro, the driver program 24120 will pass the argument `-lgcc' to tell the linker to do the search. 24121 24122 -- Macro: LINK_GCC_C_SEQUENCE_SPEC 24123 The sequence in which libgcc and libc are specified to the linker. 24124 By default this is `%G %L %G'. 24125 24126 -- Macro: LINK_COMMAND_SPEC 24127 A C string constant giving the complete command line need to 24128 execute the linker. When you do this, you will need to update 24129 your port each time a change is made to the link command line 24130 within `gcc.c'. Therefore, define this macro only if you need to 24131 completely redefine the command line for invoking the linker and 24132 there is no other way to accomplish the effect you need. 24133 Overriding this macro may be avoidable by overriding 24134 `LINK_GCC_C_SEQUENCE_SPEC' instead. 24135 24136 -- Macro: LINK_ELIMINATE_DUPLICATE_LDIRECTORIES 24137 A nonzero value causes `collect2' to remove duplicate 24138 `-LDIRECTORY' search directories from linking commands. Do not 24139 give it a nonzero value if removing duplicate search directories 24140 changes the linker's semantics. 24141 24142 -- Macro: MULTILIB_DEFAULTS 24143 Define this macro as a C expression for the initializer of an 24144 array of string to tell the driver program which options are 24145 defaults for this target and thus do not need to be handled 24146 specially when using `MULTILIB_OPTIONS'. 24147 24148 Do not define this macro if `MULTILIB_OPTIONS' is not defined in 24149 the target makefile fragment or if none of the options listed in 24150 `MULTILIB_OPTIONS' are set by default. *Note Target Fragment::. 24151 24152 -- Macro: RELATIVE_PREFIX_NOT_LINKDIR 24153 Define this macro to tell `gcc' that it should only translate a 24154 `-B' prefix into a `-L' linker option if the prefix indicates an 24155 absolute file name. 24156 24157 -- Macro: MD_EXEC_PREFIX 24158 If defined, this macro is an additional prefix to try after 24159 `STANDARD_EXEC_PREFIX'. `MD_EXEC_PREFIX' is not searched when the 24160 `-b' option is used, or the compiler is built as a cross compiler. 24161 If you define `MD_EXEC_PREFIX', then be sure to add it to the 24162 list of directories used to find the assembler in `configure.in'. 24163 24164 -- Macro: STANDARD_STARTFILE_PREFIX 24165 Define this macro as a C string constant if you wish to override 24166 the standard choice of `libdir' as the default prefix to try when 24167 searching for startup files such as `crt0.o'. 24168 `STANDARD_STARTFILE_PREFIX' is not searched when the compiler is 24169 built as a cross compiler. 24170 24171 -- Macro: STANDARD_STARTFILE_PREFIX_1 24172 Define this macro as a C string constant if you wish to override 24173 the standard choice of `/lib' as a prefix to try after the default 24174 prefix when searching for startup files such as `crt0.o'. 24175 `STANDARD_STARTFILE_PREFIX_1' is not searched when the compiler is 24176 built as a cross compiler. 24177 24178 -- Macro: STANDARD_STARTFILE_PREFIX_2 24179 Define this macro as a C string constant if you wish to override 24180 the standard choice of `/lib' as yet another prefix to try after 24181 the default prefix when searching for startup files such as 24182 `crt0.o'. `STANDARD_STARTFILE_PREFIX_2' is not searched when the 24183 compiler is built as a cross compiler. 24184 24185 -- Macro: MD_STARTFILE_PREFIX 24186 If defined, this macro supplies an additional prefix to try after 24187 the standard prefixes. `MD_EXEC_PREFIX' is not searched when the 24188 `-b' option is used, or when the compiler is built as a cross 24189 compiler. 24190 24191 -- Macro: MD_STARTFILE_PREFIX_1 24192 If defined, this macro supplies yet another prefix to try after the 24193 standard prefixes. It is not searched when the `-b' option is 24194 used, or when the compiler is built as a cross compiler. 24195 24196 -- Macro: INIT_ENVIRONMENT 24197 Define this macro as a C string constant if you wish to set 24198 environment variables for programs called by the driver, such as 24199 the assembler and loader. The driver passes the value of this 24200 macro to `putenv' to initialize the necessary environment 24201 variables. 24202 24203 -- Macro: LOCAL_INCLUDE_DIR 24204 Define this macro as a C string constant if you wish to override 24205 the standard choice of `/usr/local/include' as the default prefix 24206 to try when searching for local header files. `LOCAL_INCLUDE_DIR' 24207 comes before `SYSTEM_INCLUDE_DIR' in the search order. 24208 24209 Cross compilers do not search either `/usr/local/include' or its 24210 replacement. 24211 24212 -- Macro: MODIFY_TARGET_NAME 24213 Define this macro if you wish to define command-line switches that 24214 modify the default target name. 24215 24216 For each switch, you can include a string to be appended to the 24217 first part of the configuration name or a string to be deleted 24218 from the configuration name, if present. The definition should be 24219 an initializer for an array of structures. Each array element 24220 should have three elements: the switch name (a string constant, 24221 including the initial dash), one of the enumeration codes `ADD' or 24222 `DELETE' to indicate whether the string should be inserted or 24223 deleted, and the string to be inserted or deleted (a string 24224 constant). 24225 24226 For example, on a machine where `64' at the end of the 24227 configuration name denotes a 64-bit target and you want the `-32' 24228 and `-64' switches to select between 32- and 64-bit targets, you 24229 would code 24230 24231 #define MODIFY_TARGET_NAME \ 24232 { { "-32", DELETE, "64"}, \ 24233 {"-64", ADD, "64"}} 24234 24235 -- Macro: SYSTEM_INCLUDE_DIR 24236 Define this macro as a C string constant if you wish to specify a 24237 system-specific directory to search for header files before the 24238 standard directory. `SYSTEM_INCLUDE_DIR' comes before 24239 `STANDARD_INCLUDE_DIR' in the search order. 24240 24241 Cross compilers do not use this macro and do not search the 24242 directory specified. 24243 24244 -- Macro: STANDARD_INCLUDE_DIR 24245 Define this macro as a C string constant if you wish to override 24246 the standard choice of `/usr/include' as the default prefix to try 24247 when searching for header files. 24248 24249 Cross compilers ignore this macro and do not search either 24250 `/usr/include' or its replacement. 24251 24252 -- Macro: STANDARD_INCLUDE_COMPONENT 24253 The "component" corresponding to `STANDARD_INCLUDE_DIR'. See 24254 `INCLUDE_DEFAULTS', below, for the description of components. If 24255 you do not define this macro, no component is used. 24256 24257 -- Macro: INCLUDE_DEFAULTS 24258 Define this macro if you wish to override the entire default 24259 search path for include files. For a native compiler, the default 24260 search path usually consists of `GCC_INCLUDE_DIR', 24261 `LOCAL_INCLUDE_DIR', `SYSTEM_INCLUDE_DIR', 24262 `GPLUSPLUS_INCLUDE_DIR', and `STANDARD_INCLUDE_DIR'. In addition, 24263 `GPLUSPLUS_INCLUDE_DIR' and `GCC_INCLUDE_DIR' are defined 24264 automatically by `Makefile', and specify private search areas for 24265 GCC. The directory `GPLUSPLUS_INCLUDE_DIR' is used only for C++ 24266 programs. 24267 24268 The definition should be an initializer for an array of structures. 24269 Each array element should have four elements: the directory name (a 24270 string constant), the component name (also a string constant), a 24271 flag for C++-only directories, and a flag showing that the 24272 includes in the directory don't need to be wrapped in `extern `C'' 24273 when compiling C++. Mark the end of the array with a null element. 24274 24275 The component name denotes what GNU package the include file is 24276 part of, if any, in all uppercase letters. For example, it might 24277 be `GCC' or `BINUTILS'. If the package is part of a 24278 vendor-supplied operating system, code the component name as `0'. 24279 24280 For example, here is the definition used for VAX/VMS: 24281 24282 #define INCLUDE_DEFAULTS \ 24283 { \ 24284 { "GNU_GXX_INCLUDE:", "G++", 1, 1}, \ 24285 { "GNU_CC_INCLUDE:", "GCC", 0, 0}, \ 24286 { "SYS$SYSROOT:[SYSLIB.]", 0, 0, 0}, \ 24287 { ".", 0, 0, 0}, \ 24288 { 0, 0, 0, 0} \ 24289 } 24290 24291 Here is the order of prefixes tried for exec files: 24292 24293 1. Any prefixes specified by the user with `-B'. 24294 24295 2. The environment variable `GCC_EXEC_PREFIX' or, if `GCC_EXEC_PREFIX' 24296 is not set and the compiler has not been installed in the 24297 configure-time PREFIX, the location in which the compiler has 24298 actually been installed. 24299 24300 3. The directories specified by the environment variable 24301 `COMPILER_PATH'. 24302 24303 4. The macro `STANDARD_EXEC_PREFIX', if the compiler has been 24304 installed in the configured-time PREFIX. 24305 24306 5. The location `/usr/libexec/gcc/', but only if this is a native 24307 compiler. 24308 24309 6. The location `/usr/lib/gcc/', but only if this is a native 24310 compiler. 24311 24312 7. The macro `MD_EXEC_PREFIX', if defined, but only if this is a 24313 native compiler. 24314 24315 Here is the order of prefixes tried for startfiles: 24316 24317 1. Any prefixes specified by the user with `-B'. 24318 24319 2. The environment variable `GCC_EXEC_PREFIX' or its automatically 24320 determined value based on the installed toolchain location. 24321 24322 3. The directories specified by the environment variable 24323 `LIBRARY_PATH' (or port-specific name; native only, cross 24324 compilers do not use this). 24325 24326 4. The macro `STANDARD_EXEC_PREFIX', but only if the toolchain is 24327 installed in the configured PREFIX or this is a native compiler. 24328 24329 5. The location `/usr/lib/gcc/', but only if this is a native 24330 compiler. 24331 24332 6. The macro `MD_EXEC_PREFIX', if defined, but only if this is a 24333 native compiler. 24334 24335 7. The macro `MD_STARTFILE_PREFIX', if defined, but only if this is a 24336 native compiler, or we have a target system root. 24337 24338 8. The macro `MD_STARTFILE_PREFIX_1', if defined, but only if this is 24339 a native compiler, or we have a target system root. 24340 24341 9. The macro `STANDARD_STARTFILE_PREFIX', with any sysroot 24342 modifications. If this path is relative it will be prefixed by 24343 `GCC_EXEC_PREFIX' and the machine suffix or `STANDARD_EXEC_PREFIX' 24344 and the machine suffix. 24345 24346 10. The macro `STANDARD_STARTFILE_PREFIX_1', but only if this is a 24347 native compiler, or we have a target system root. The default for 24348 this macro is `/lib/'. 24349 24350 11. The macro `STANDARD_STARTFILE_PREFIX_2', but only if this is a 24351 native compiler, or we have a target system root. The default for 24352 this macro is `/usr/lib/'. 24353 24354 24355 File: gccint.info, Node: Run-time Target, Next: Per-Function Data, Prev: Driver, Up: Target Macros 24356 24357 17.3 Run-time Target Specification 24358 ================================== 24359 24360 Here are run-time target specifications. 24361 24362 -- Macro: TARGET_CPU_CPP_BUILTINS () 24363 This function-like macro expands to a block of code that defines 24364 built-in preprocessor macros and assertions for the target CPU, 24365 using the functions `builtin_define', `builtin_define_std' and 24366 `builtin_assert'. When the front end calls this macro it provides 24367 a trailing semicolon, and since it has finished command line 24368 option processing your code can use those results freely. 24369 24370 `builtin_assert' takes a string in the form you pass to the 24371 command-line option `-A', such as `cpu=mips', and creates the 24372 assertion. `builtin_define' takes a string in the form accepted 24373 by option `-D' and unconditionally defines the macro. 24374 24375 `builtin_define_std' takes a string representing the name of an 24376 object-like macro. If it doesn't lie in the user's namespace, 24377 `builtin_define_std' defines it unconditionally. Otherwise, it 24378 defines a version with two leading underscores, and another version 24379 with two leading and trailing underscores, and defines the original 24380 only if an ISO standard was not requested on the command line. For 24381 example, passing `unix' defines `__unix', `__unix__' and possibly 24382 `unix'; passing `_mips' defines `__mips', `__mips__' and possibly 24383 `_mips', and passing `_ABI64' defines only `_ABI64'. 24384 24385 You can also test for the C dialect being compiled. The variable 24386 `c_language' is set to one of `clk_c', `clk_cplusplus' or 24387 `clk_objective_c'. Note that if we are preprocessing assembler, 24388 this variable will be `clk_c' but the function-like macro 24389 `preprocessing_asm_p()' will return true, so you might want to 24390 check for that first. If you need to check for strict ANSI, the 24391 variable `flag_iso' can be used. The function-like macro 24392 `preprocessing_trad_p()' can be used to check for traditional 24393 preprocessing. 24394 24395 -- Macro: TARGET_OS_CPP_BUILTINS () 24396 Similarly to `TARGET_CPU_CPP_BUILTINS' but this macro is optional 24397 and is used for the target operating system instead. 24398 24399 -- Macro: TARGET_OBJFMT_CPP_BUILTINS () 24400 Similarly to `TARGET_CPU_CPP_BUILTINS' but this macro is optional 24401 and is used for the target object format. `elfos.h' uses this 24402 macro to define `__ELF__', so you probably do not need to define 24403 it yourself. 24404 24405 -- Variable: extern int target_flags 24406 This variable is declared in `options.h', which is included before 24407 any target-specific headers. 24408 24409 -- Variable: Target Hook int TARGET_DEFAULT_TARGET_FLAGS 24410 This variable specifies the initial value of `target_flags'. Its 24411 default setting is 0. 24412 24413 -- Target Hook: bool TARGET_HANDLE_OPTION (size_t CODE, const char 24414 *ARG, int VALUE) 24415 This hook is called whenever the user specifies one of the 24416 target-specific options described by the `.opt' definition files 24417 (*note Options::). It has the opportunity to do some 24418 option-specific processing and should return true if the option is 24419 valid. The default definition does nothing but return true. 24420 24421 CODE specifies the `OPT_NAME' enumeration value associated with 24422 the selected option; NAME is just a rendering of the option name 24423 in which non-alphanumeric characters are replaced by underscores. 24424 ARG specifies the string argument and is null if no argument was 24425 given. If the option is flagged as a `UInteger' (*note Option 24426 properties::), VALUE is the numeric value of the argument. 24427 Otherwise VALUE is 1 if the positive form of the option was used 24428 and 0 if the "no-" form was. 24429 24430 -- Target Hook: bool TARGET_HANDLE_C_OPTION (size_t CODE, const char 24431 *ARG, int VALUE) 24432 This target hook is called whenever the user specifies one of the 24433 target-specific C language family options described by the `.opt' 24434 definition files(*note Options::). It has the opportunity to do 24435 some option-specific processing and should return true if the 24436 option is valid. The default definition does nothing but return 24437 false. 24438 24439 In general, you should use `TARGET_HANDLE_OPTION' to handle 24440 options. However, if processing an option requires routines that 24441 are only available in the C (and related language) front ends, 24442 then you should use `TARGET_HANDLE_C_OPTION' instead. 24443 24444 -- Macro: TARGET_VERSION 24445 This macro is a C statement to print on `stderr' a string 24446 describing the particular machine description choice. Every 24447 machine description should define `TARGET_VERSION'. For example: 24448 24449 #ifdef MOTOROLA 24450 #define TARGET_VERSION \ 24451 fprintf (stderr, " (68k, Motorola syntax)"); 24452 #else 24453 #define TARGET_VERSION \ 24454 fprintf (stderr, " (68k, MIT syntax)"); 24455 #endif 24456 24457 -- Macro: OVERRIDE_OPTIONS 24458 Sometimes certain combinations of command options do not make 24459 sense on a particular target machine. You can define a macro 24460 `OVERRIDE_OPTIONS' to take account of this. This macro, if 24461 defined, is executed once just after all the command options have 24462 been parsed. 24463 24464 Don't use this macro to turn on various extra optimizations for 24465 `-O'. That is what `OPTIMIZATION_OPTIONS' is for. 24466 24467 -- Macro: C_COMMON_OVERRIDE_OPTIONS 24468 This is similar to `OVERRIDE_OPTIONS' but is only used in the C 24469 language frontends (C, Objective-C, C++, Objective-C++) and so can 24470 be used to alter option flag variables which only exist in those 24471 frontends. 24472 24473 -- Macro: OPTIMIZATION_OPTIONS (LEVEL, SIZE) 24474 Some machines may desire to change what optimizations are 24475 performed for various optimization levels. This macro, if 24476 defined, is executed once just after the optimization level is 24477 determined and before the remainder of the command options have 24478 been parsed. Values set in this macro are used as the default 24479 values for the other command line options. 24480 24481 LEVEL is the optimization level specified; 2 if `-O2' is 24482 specified, 1 if `-O' is specified, and 0 if neither is specified. 24483 24484 SIZE is nonzero if `-Os' is specified and zero otherwise. 24485 24486 This macro is run once at program startup and when the optimization 24487 options are changed via `#pragma GCC optimize' or by using the 24488 `optimize' attribute. 24489 24490 *Do not examine `write_symbols' in this macro!* The debugging 24491 options are not supposed to alter the generated code. 24492 24493 -- Target Hook: bool TARGET_HELP (void) 24494 This hook is called in response to the user invoking 24495 `--target-help' on the command line. It gives the target a chance 24496 to display extra information on the target specific command line 24497 options found in its `.opt' file. 24498 24499 -- Macro: CAN_DEBUG_WITHOUT_FP 24500 Define this macro if debugging can be performed even without a 24501 frame pointer. If this macro is defined, GCC will turn on the 24502 `-fomit-frame-pointer' option whenever `-O' is specified. 24503 24504 24505 File: gccint.info, Node: Per-Function Data, Next: Storage Layout, Prev: Run-time Target, Up: Target Macros 24506 24507 17.4 Defining data structures for per-function information. 24508 =========================================================== 24509 24510 If the target needs to store information on a per-function basis, GCC 24511 provides a macro and a couple of variables to allow this. Note, just 24512 using statics to store the information is a bad idea, since GCC supports 24513 nested functions, so you can be halfway through encoding one function 24514 when another one comes along. 24515 24516 GCC defines a data structure called `struct function' which contains 24517 all of the data specific to an individual function. This structure 24518 contains a field called `machine' whose type is `struct 24519 machine_function *', which can be used by targets to point to their own 24520 specific data. 24521 24522 If a target needs per-function specific data it should define the type 24523 `struct machine_function' and also the macro `INIT_EXPANDERS'. This 24524 macro should be used to initialize the function pointer 24525 `init_machine_status'. This pointer is explained below. 24526 24527 One typical use of per-function, target specific data is to create an 24528 RTX to hold the register containing the function's return address. This 24529 RTX can then be used to implement the `__builtin_return_address' 24530 function, for level 0. 24531 24532 Note--earlier implementations of GCC used a single data area to hold 24533 all of the per-function information. Thus when processing of a nested 24534 function began the old per-function data had to be pushed onto a stack, 24535 and when the processing was finished, it had to be popped off the 24536 stack. GCC used to provide function pointers called 24537 `save_machine_status' and `restore_machine_status' to handle the saving 24538 and restoring of the target specific information. Since the single 24539 data area approach is no longer used, these pointers are no longer 24540 supported. 24541 24542 -- Macro: INIT_EXPANDERS 24543 Macro called to initialize any target specific information. This 24544 macro is called once per function, before generation of any RTL 24545 has begun. The intention of this macro is to allow the 24546 initialization of the function pointer `init_machine_status'. 24547 24548 -- Variable: void (*)(struct function *) init_machine_status 24549 If this function pointer is non-`NULL' it will be called once per 24550 function, before function compilation starts, in order to allow the 24551 target to perform any target specific initialization of the 24552 `struct function' structure. It is intended that this would be 24553 used to initialize the `machine' of that structure. 24554 24555 `struct machine_function' structures are expected to be freed by 24556 GC. Generally, any memory that they reference must be allocated 24557 by using `ggc_alloc', including the structure itself. 24558 24559 24560 File: gccint.info, Node: Storage Layout, Next: Type Layout, Prev: Per-Function Data, Up: Target Macros 24561 24562 17.5 Storage Layout 24563 =================== 24564 24565 Note that the definitions of the macros in this table which are sizes or 24566 alignments measured in bits do not need to be constant. They can be C 24567 expressions that refer to static variables, such as the `target_flags'. 24568 *Note Run-time Target::. 24569 24570 -- Macro: BITS_BIG_ENDIAN 24571 Define this macro to have the value 1 if the most significant bit 24572 in a byte has the lowest number; otherwise define it to have the 24573 value zero. This means that bit-field instructions count from the 24574 most significant bit. If the machine has no bit-field 24575 instructions, then this must still be defined, but it doesn't 24576 matter which value it is defined to. This macro need not be a 24577 constant. 24578 24579 This macro does not affect the way structure fields are packed into 24580 bytes or words; that is controlled by `BYTES_BIG_ENDIAN'. 24581 24582 -- Macro: BYTES_BIG_ENDIAN 24583 Define this macro to have the value 1 if the most significant byte 24584 in a word has the lowest number. This macro need not be a 24585 constant. 24586 24587 -- Macro: WORDS_BIG_ENDIAN 24588 Define this macro to have the value 1 if, in a multiword object, 24589 the most significant word has the lowest number. This applies to 24590 both memory locations and registers; GCC fundamentally assumes 24591 that the order of words in memory is the same as the order in 24592 registers. This macro need not be a constant. 24593 24594 -- Macro: LIBGCC2_WORDS_BIG_ENDIAN 24595 Define this macro if `WORDS_BIG_ENDIAN' is not constant. This 24596 must be a constant value with the same meaning as 24597 `WORDS_BIG_ENDIAN', which will be used only when compiling 24598 `libgcc2.c'. Typically the value will be set based on 24599 preprocessor defines. 24600 24601 -- Macro: FLOAT_WORDS_BIG_ENDIAN 24602 Define this macro to have the value 1 if `DFmode', `XFmode' or 24603 `TFmode' floating point numbers are stored in memory with the word 24604 containing the sign bit at the lowest address; otherwise define it 24605 to have the value 0. This macro need not be a constant. 24606 24607 You need not define this macro if the ordering is the same as for 24608 multi-word integers. 24609 24610 -- Macro: BITS_PER_UNIT 24611 Define this macro to be the number of bits in an addressable 24612 storage unit (byte). If you do not define this macro the default 24613 is 8. 24614 24615 -- Macro: BITS_PER_WORD 24616 Number of bits in a word. If you do not define this macro, the 24617 default is `BITS_PER_UNIT * UNITS_PER_WORD'. 24618 24619 -- Macro: MAX_BITS_PER_WORD 24620 Maximum number of bits in a word. If this is undefined, the 24621 default is `BITS_PER_WORD'. Otherwise, it is the constant value 24622 that is the largest value that `BITS_PER_WORD' can have at 24623 run-time. 24624 24625 -- Macro: UNITS_PER_WORD 24626 Number of storage units in a word; normally the size of a 24627 general-purpose register, a power of two from 1 or 8. 24628 24629 -- Macro: MIN_UNITS_PER_WORD 24630 Minimum number of units in a word. If this is undefined, the 24631 default is `UNITS_PER_WORD'. Otherwise, it is the constant value 24632 that is the smallest value that `UNITS_PER_WORD' can have at 24633 run-time. 24634 24635 -- Macro: UNITS_PER_SIMD_WORD (MODE) 24636 Number of units in the vectors that the vectorizer can produce for 24637 scalar mode MODE. The default is equal to `UNITS_PER_WORD', 24638 because the vectorizer can do some transformations even in absence 24639 of specialized SIMD hardware. 24640 24641 -- Macro: POINTER_SIZE 24642 Width of a pointer, in bits. You must specify a value no wider 24643 than the width of `Pmode'. If it is not equal to the width of 24644 `Pmode', you must define `POINTERS_EXTEND_UNSIGNED'. If you do 24645 not specify a value the default is `BITS_PER_WORD'. 24646 24647 -- Macro: POINTERS_EXTEND_UNSIGNED 24648 A C expression that determines how pointers should be extended from 24649 `ptr_mode' to either `Pmode' or `word_mode'. It is greater than 24650 zero if pointers should be zero-extended, zero if they should be 24651 sign-extended, and negative if some other sort of conversion is 24652 needed. In the last case, the extension is done by the target's 24653 `ptr_extend' instruction. 24654 24655 You need not define this macro if the `ptr_mode', `Pmode' and 24656 `word_mode' are all the same width. 24657 24658 -- Macro: PROMOTE_MODE (M, UNSIGNEDP, TYPE) 24659 A macro to update M and UNSIGNEDP when an object whose type is 24660 TYPE and which has the specified mode and signedness is to be 24661 stored in a register. This macro is only called when TYPE is a 24662 scalar type. 24663 24664 On most RISC machines, which only have operations that operate on 24665 a full register, define this macro to set M to `word_mode' if M is 24666 an integer mode narrower than `BITS_PER_WORD'. In most cases, 24667 only integer modes should be widened because wider-precision 24668 floating-point operations are usually more expensive than their 24669 narrower counterparts. 24670 24671 For most machines, the macro definition does not change UNSIGNEDP. 24672 However, some machines, have instructions that preferentially 24673 handle either signed or unsigned quantities of certain modes. For 24674 example, on the DEC Alpha, 32-bit loads from memory and 32-bit add 24675 instructions sign-extend the result to 64 bits. On such machines, 24676 set UNSIGNEDP according to which kind of extension is more 24677 efficient. 24678 24679 Do not define this macro if it would never modify M. 24680 24681 -- Macro: PROMOTE_FUNCTION_MODE 24682 Like `PROMOTE_MODE', but is applied to outgoing function arguments 24683 or function return values, as specified by 24684 `TARGET_PROMOTE_FUNCTION_ARGS' and 24685 `TARGET_PROMOTE_FUNCTION_RETURN', respectively. 24686 24687 The default is `PROMOTE_MODE'. 24688 24689 -- Target Hook: bool TARGET_PROMOTE_FUNCTION_ARGS (tree FNTYPE) 24690 This target hook should return `true' if the promotion described by 24691 `PROMOTE_FUNCTION_MODE' should be done for outgoing function 24692 arguments. 24693 24694 -- Target Hook: bool TARGET_PROMOTE_FUNCTION_RETURN (tree FNTYPE) 24695 This target hook should return `true' if the promotion described by 24696 `PROMOTE_FUNCTION_MODE' should be done for the return value of 24697 functions. 24698 24699 If this target hook returns `true', `TARGET_FUNCTION_VALUE' must 24700 perform the same promotions done by `PROMOTE_FUNCTION_MODE'. 24701 24702 -- Macro: PARM_BOUNDARY 24703 Normal alignment required for function parameters on the stack, in 24704 bits. All stack parameters receive at least this much alignment 24705 regardless of data type. On most machines, this is the same as the 24706 size of an integer. 24707 24708 -- Macro: STACK_BOUNDARY 24709 Define this macro to the minimum alignment enforced by hardware 24710 for the stack pointer on this machine. The definition is a C 24711 expression for the desired alignment (measured in bits). This 24712 value is used as a default if `PREFERRED_STACK_BOUNDARY' is not 24713 defined. On most machines, this should be the same as 24714 `PARM_BOUNDARY'. 24715 24716 -- Macro: PREFERRED_STACK_BOUNDARY 24717 Define this macro if you wish to preserve a certain alignment for 24718 the stack pointer, greater than what the hardware enforces. The 24719 definition is a C expression for the desired alignment (measured 24720 in bits). This macro must evaluate to a value equal to or larger 24721 than `STACK_BOUNDARY'. 24722 24723 -- Macro: INCOMING_STACK_BOUNDARY 24724 Define this macro if the incoming stack boundary may be different 24725 from `PREFERRED_STACK_BOUNDARY'. This macro must evaluate to a 24726 value equal to or larger than `STACK_BOUNDARY'. 24727 24728 -- Macro: FUNCTION_BOUNDARY 24729 Alignment required for a function entry point, in bits. 24730 24731 -- Macro: BIGGEST_ALIGNMENT 24732 Biggest alignment that any data type can require on this machine, 24733 in bits. Note that this is not the biggest alignment that is 24734 supported, just the biggest alignment that, when violated, may 24735 cause a fault. 24736 24737 -- Macro: MALLOC_ABI_ALIGNMENT 24738 Alignment, in bits, a C conformant malloc implementation has to 24739 provide. If not defined, the default value is `BITS_PER_WORD'. 24740 24741 -- Macro: ATTRIBUTE_ALIGNED_VALUE 24742 Alignment used by the `__attribute__ ((aligned))' construct. If 24743 not defined, the default value is `BIGGEST_ALIGNMENT'. 24744 24745 -- Macro: MINIMUM_ATOMIC_ALIGNMENT 24746 If defined, the smallest alignment, in bits, that can be given to 24747 an object that can be referenced in one operation, without 24748 disturbing any nearby object. Normally, this is `BITS_PER_UNIT', 24749 but may be larger on machines that don't have byte or half-word 24750 store operations. 24751 24752 -- Macro: BIGGEST_FIELD_ALIGNMENT 24753 Biggest alignment that any structure or union field can require on 24754 this machine, in bits. If defined, this overrides 24755 `BIGGEST_ALIGNMENT' for structure and union fields only, unless 24756 the field alignment has been set by the `__attribute__ ((aligned 24757 (N)))' construct. 24758 24759 -- Macro: ADJUST_FIELD_ALIGN (FIELD, COMPUTED) 24760 An expression for the alignment of a structure field FIELD if the 24761 alignment computed in the usual way (including applying of 24762 `BIGGEST_ALIGNMENT' and `BIGGEST_FIELD_ALIGNMENT' to the 24763 alignment) is COMPUTED. It overrides alignment only if the field 24764 alignment has not been set by the `__attribute__ ((aligned (N)))' 24765 construct. 24766 24767 -- Macro: MAX_STACK_ALIGNMENT 24768 Biggest stack alignment guaranteed by the backend. Use this macro 24769 to specify the maximum alignment of a variable on stack. 24770 24771 If not defined, the default value is `STACK_BOUNDARY'. 24772 24773 24774 -- Macro: MAX_OFILE_ALIGNMENT 24775 Biggest alignment supported by the object file format of this 24776 machine. Use this macro to limit the alignment which can be 24777 specified using the `__attribute__ ((aligned (N)))' construct. If 24778 not defined, the default value is `BIGGEST_ALIGNMENT'. 24779 24780 On systems that use ELF, the default (in `config/elfos.h') is the 24781 largest supported 32-bit ELF section alignment representable on a 24782 32-bit host e.g. `(((unsigned HOST_WIDEST_INT) 1 << 28) * 8)'. On 24783 32-bit ELF the largest supported section alignment in bits is 24784 `(0x80000000 * 8)', but this is not representable on 32-bit hosts. 24785 24786 -- Macro: DATA_ALIGNMENT (TYPE, BASIC-ALIGN) 24787 If defined, a C expression to compute the alignment for a variable 24788 in the static store. TYPE is the data type, and BASIC-ALIGN is 24789 the alignment that the object would ordinarily have. The value of 24790 this macro is used instead of that alignment to align the object. 24791 24792 If this macro is not defined, then BASIC-ALIGN is used. 24793 24794 One use of this macro is to increase alignment of medium-size data 24795 to make it all fit in fewer cache lines. Another is to cause 24796 character arrays to be word-aligned so that `strcpy' calls that 24797 copy constants to character arrays can be done inline. 24798 24799 -- Macro: CONSTANT_ALIGNMENT (CONSTANT, BASIC-ALIGN) 24800 If defined, a C expression to compute the alignment given to a 24801 constant that is being placed in memory. CONSTANT is the constant 24802 and BASIC-ALIGN is the alignment that the object would ordinarily 24803 have. The value of this macro is used instead of that alignment to 24804 align the object. 24805 24806 If this macro is not defined, then BASIC-ALIGN is used. 24807 24808 The typical use of this macro is to increase alignment for string 24809 constants to be word aligned so that `strcpy' calls that copy 24810 constants can be done inline. 24811 24812 -- Macro: LOCAL_ALIGNMENT (TYPE, BASIC-ALIGN) 24813 If defined, a C expression to compute the alignment for a variable 24814 in the local store. TYPE is the data type, and BASIC-ALIGN is the 24815 alignment that the object would ordinarily have. The value of this 24816 macro is used instead of that alignment to align the object. 24817 24818 If this macro is not defined, then BASIC-ALIGN is used. 24819 24820 One use of this macro is to increase alignment of medium-size data 24821 to make it all fit in fewer cache lines. 24822 24823 -- Macro: STACK_SLOT_ALIGNMENT (TYPE, MODE, BASIC-ALIGN) 24824 If defined, a C expression to compute the alignment for stack slot. 24825 TYPE is the data type, MODE is the widest mode available, and 24826 BASIC-ALIGN is the alignment that the slot would ordinarily have. 24827 The value of this macro is used instead of that alignment to align 24828 the slot. 24829 24830 If this macro is not defined, then BASIC-ALIGN is used when TYPE 24831 is `NULL'. Otherwise, `LOCAL_ALIGNMENT' will be used. 24832 24833 This macro is to set alignment of stack slot to the maximum 24834 alignment of all possible modes which the slot may have. 24835 24836 -- Macro: LOCAL_DECL_ALIGNMENT (DECL) 24837 If defined, a C expression to compute the alignment for a local 24838 variable DECL. 24839 24840 If this macro is not defined, then `LOCAL_ALIGNMENT (TREE_TYPE 24841 (DECL), DECL_ALIGN (DECL))' is used. 24842 24843 One use of this macro is to increase alignment of medium-size data 24844 to make it all fit in fewer cache lines. 24845 24846 -- Macro: MINIMUM_ALIGNMENT (EXP, MODE, ALIGN) 24847 If defined, a C expression to compute the minimum required 24848 alignment for dynamic stack realignment purposes for EXP (a type 24849 or decl), MODE, assuming normal alignment ALIGN. 24850 24851 If this macro is not defined, then ALIGN will be used. 24852 24853 -- Macro: EMPTY_FIELD_BOUNDARY 24854 Alignment in bits to be given to a structure bit-field that 24855 follows an empty field such as `int : 0;'. 24856 24857 If `PCC_BITFIELD_TYPE_MATTERS' is true, it overrides this macro. 24858 24859 -- Macro: STRUCTURE_SIZE_BOUNDARY 24860 Number of bits which any structure or union's size must be a 24861 multiple of. Each structure or union's size is rounded up to a 24862 multiple of this. 24863 24864 If you do not define this macro, the default is the same as 24865 `BITS_PER_UNIT'. 24866 24867 -- Macro: STRICT_ALIGNMENT 24868 Define this macro to be the value 1 if instructions will fail to 24869 work if given data not on the nominal alignment. If instructions 24870 will merely go slower in that case, define this macro as 0. 24871 24872 -- Macro: PCC_BITFIELD_TYPE_MATTERS 24873 Define this if you wish to imitate the way many other C compilers 24874 handle alignment of bit-fields and the structures that contain 24875 them. 24876 24877 The behavior is that the type written for a named bit-field (`int', 24878 `short', or other integer type) imposes an alignment for the entire 24879 structure, as if the structure really did contain an ordinary 24880 field of that type. In addition, the bit-field is placed within 24881 the structure so that it would fit within such a field, not 24882 crossing a boundary for it. 24883 24884 Thus, on most machines, a named bit-field whose type is written as 24885 `int' would not cross a four-byte boundary, and would force 24886 four-byte alignment for the whole structure. (The alignment used 24887 may not be four bytes; it is controlled by the other alignment 24888 parameters.) 24889 24890 An unnamed bit-field will not affect the alignment of the 24891 containing structure. 24892 24893 If the macro is defined, its definition should be a C expression; 24894 a nonzero value for the expression enables this behavior. 24895 24896 Note that if this macro is not defined, or its value is zero, some 24897 bit-fields may cross more than one alignment boundary. The 24898 compiler can support such references if there are `insv', `extv', 24899 and `extzv' insns that can directly reference memory. 24900 24901 The other known way of making bit-fields work is to define 24902 `STRUCTURE_SIZE_BOUNDARY' as large as `BIGGEST_ALIGNMENT'. Then 24903 every structure can be accessed with fullwords. 24904 24905 Unless the machine has bit-field instructions or you define 24906 `STRUCTURE_SIZE_BOUNDARY' that way, you must define 24907 `PCC_BITFIELD_TYPE_MATTERS' to have a nonzero value. 24908 24909 If your aim is to make GCC use the same conventions for laying out 24910 bit-fields as are used by another compiler, here is how to 24911 investigate what the other compiler does. Compile and run this 24912 program: 24913 24914 struct foo1 24915 { 24916 char x; 24917 char :0; 24918 char y; 24919 }; 24920 24921 struct foo2 24922 { 24923 char x; 24924 int :0; 24925 char y; 24926 }; 24927 24928 main () 24929 { 24930 printf ("Size of foo1 is %d\n", 24931 sizeof (struct foo1)); 24932 printf ("Size of foo2 is %d\n", 24933 sizeof (struct foo2)); 24934 exit (0); 24935 } 24936 24937 If this prints 2 and 5, then the compiler's behavior is what you 24938 would get from `PCC_BITFIELD_TYPE_MATTERS'. 24939 24940 -- Macro: BITFIELD_NBYTES_LIMITED 24941 Like `PCC_BITFIELD_TYPE_MATTERS' except that its effect is limited 24942 to aligning a bit-field within the structure. 24943 24944 -- Target Hook: bool TARGET_ALIGN_ANON_BITFIELD (void) 24945 When `PCC_BITFIELD_TYPE_MATTERS' is true this hook will determine 24946 whether unnamed bitfields affect the alignment of the containing 24947 structure. The hook should return true if the structure should 24948 inherit the alignment requirements of an unnamed bitfield's type. 24949 24950 -- Target Hook: bool TARGET_NARROW_VOLATILE_BITFIELD (void) 24951 This target hook should return `true' if accesses to volatile 24952 bitfields should use the narrowest mode possible. It should 24953 return `false' if these accesses should use the bitfield container 24954 type. 24955 24956 The default is `!TARGET_STRICT_ALIGN'. 24957 24958 -- Macro: MEMBER_TYPE_FORCES_BLK (FIELD, MODE) 24959 Return 1 if a structure or array containing FIELD should be 24960 accessed using `BLKMODE'. 24961 24962 If FIELD is the only field in the structure, MODE is its mode, 24963 otherwise MODE is VOIDmode. MODE is provided in the case where 24964 structures of one field would require the structure's mode to 24965 retain the field's mode. 24966 24967 Normally, this is not needed. 24968 24969 -- Macro: ROUND_TYPE_ALIGN (TYPE, COMPUTED, SPECIFIED) 24970 Define this macro as an expression for the alignment of a type 24971 (given by TYPE as a tree node) if the alignment computed in the 24972 usual way is COMPUTED and the alignment explicitly specified was 24973 SPECIFIED. 24974 24975 The default is to use SPECIFIED if it is larger; otherwise, use 24976 the smaller of COMPUTED and `BIGGEST_ALIGNMENT' 24977 24978 -- Macro: MAX_FIXED_MODE_SIZE 24979 An integer expression for the size in bits of the largest integer 24980 machine mode that should actually be used. All integer machine 24981 modes of this size or smaller can be used for structures and 24982 unions with the appropriate sizes. If this macro is undefined, 24983 `GET_MODE_BITSIZE (DImode)' is assumed. 24984 24985 -- Macro: STACK_SAVEAREA_MODE (SAVE_LEVEL) 24986 If defined, an expression of type `enum machine_mode' that 24987 specifies the mode of the save area operand of a 24988 `save_stack_LEVEL' named pattern (*note Standard Names::). 24989 SAVE_LEVEL is one of `SAVE_BLOCK', `SAVE_FUNCTION', or 24990 `SAVE_NONLOCAL' and selects which of the three named patterns is 24991 having its mode specified. 24992 24993 You need not define this macro if it always returns `Pmode'. You 24994 would most commonly define this macro if the `save_stack_LEVEL' 24995 patterns need to support both a 32- and a 64-bit mode. 24996 24997 -- Macro: STACK_SIZE_MODE 24998 If defined, an expression of type `enum machine_mode' that 24999 specifies the mode of the size increment operand of an 25000 `allocate_stack' named pattern (*note Standard Names::). 25001 25002 You need not define this macro if it always returns `word_mode'. 25003 You would most commonly define this macro if the `allocate_stack' 25004 pattern needs to support both a 32- and a 64-bit mode. 25005 25006 -- Target Hook: enum machine_mode TARGET_LIBGCC_CMP_RETURN_MODE () 25007 This target hook should return the mode to be used for the return 25008 value of compare instructions expanded to libgcc calls. If not 25009 defined `word_mode' is returned which is the right choice for a 25010 majority of targets. 25011 25012 -- Target Hook: enum machine_mode TARGET_LIBGCC_SHIFT_COUNT_MODE () 25013 This target hook should return the mode to be used for the shift 25014 count operand of shift instructions expanded to libgcc calls. If 25015 not defined `word_mode' is returned which is the right choice for 25016 a majority of targets. 25017 25018 -- Macro: ROUND_TOWARDS_ZERO 25019 If defined, this macro should be true if the prevailing rounding 25020 mode is towards zero. 25021 25022 Defining this macro only affects the way `libgcc.a' emulates 25023 floating-point arithmetic. 25024 25025 Not defining this macro is equivalent to returning zero. 25026 25027 -- Macro: LARGEST_EXPONENT_IS_NORMAL (SIZE) 25028 This macro should return true if floats with SIZE bits do not have 25029 a NaN or infinity representation, but use the largest exponent for 25030 normal numbers instead. 25031 25032 Defining this macro only affects the way `libgcc.a' emulates 25033 floating-point arithmetic. 25034 25035 The default definition of this macro returns false for all sizes. 25036 25037 -- Target Hook: bool TARGET_VECTOR_OPAQUE_P (tree TYPE) 25038 This target hook should return `true' a vector is opaque. That 25039 is, if no cast is needed when copying a vector value of type TYPE 25040 into another vector lvalue of the same size. Vector opaque types 25041 cannot be initialized. The default is that there are no such 25042 types. 25043 25044 -- Target Hook: bool TARGET_MS_BITFIELD_LAYOUT_P (tree RECORD_TYPE) 25045 This target hook returns `true' if bit-fields in the given 25046 RECORD_TYPE are to be laid out following the rules of Microsoft 25047 Visual C/C++, namely: (i) a bit-field won't share the same storage 25048 unit with the previous bit-field if their underlying types have 25049 different sizes, and the bit-field will be aligned to the highest 25050 alignment of the underlying types of itself and of the previous 25051 bit-field; (ii) a zero-sized bit-field will affect the alignment of 25052 the whole enclosing structure, even if it is unnamed; except that 25053 (iii) a zero-sized bit-field will be disregarded unless it follows 25054 another bit-field of nonzero size. If this hook returns `true', 25055 other macros that control bit-field layout are ignored. 25056 25057 When a bit-field is inserted into a packed record, the whole size 25058 of the underlying type is used by one or more same-size adjacent 25059 bit-fields (that is, if its long:3, 32 bits is used in the record, 25060 and any additional adjacent long bit-fields are packed into the 25061 same chunk of 32 bits. However, if the size changes, a new field 25062 of that size is allocated). In an unpacked record, this is the 25063 same as using alignment, but not equivalent when packing. 25064 25065 If both MS bit-fields and `__attribute__((packed))' are used, the 25066 latter will take precedence. If `__attribute__((packed))' is used 25067 on a single field when MS bit-fields are in use, it will take 25068 precedence for that field, but the alignment of the rest of the 25069 structure may affect its placement. 25070 25071 -- Target Hook: bool TARGET_DECIMAL_FLOAT_SUPPORTED_P (void) 25072 Returns true if the target supports decimal floating point. 25073 25074 -- Target Hook: bool TARGET_FIXED_POINT_SUPPORTED_P (void) 25075 Returns true if the target supports fixed-point arithmetic. 25076 25077 -- Target Hook: void TARGET_EXPAND_TO_RTL_HOOK (void) 25078 This hook is called just before expansion into rtl, allowing the 25079 target to perform additional initializations or analysis before 25080 the expansion. For example, the rs6000 port uses it to allocate a 25081 scratch stack slot for use in copying SDmode values between memory 25082 and floating point registers whenever the function being expanded 25083 has any SDmode usage. 25084 25085 -- Target Hook: void TARGET_INSTANTIATE_DECLS (void) 25086 This hook allows the backend to perform additional instantiations 25087 on rtl that are not actually in any insns yet, but will be later. 25088 25089 -- Target Hook: const char * TARGET_MANGLE_TYPE (tree TYPE) 25090 If your target defines any fundamental types, or any types your 25091 target uses should be mangled differently from the default, define 25092 this hook to return the appropriate encoding for these types as 25093 part of a C++ mangled name. The TYPE argument is the tree 25094 structure representing the type to be mangled. The hook may be 25095 applied to trees which are not target-specific fundamental types; 25096 it should return `NULL' for all such types, as well as arguments 25097 it does not recognize. If the return value is not `NULL', it must 25098 point to a statically-allocated string constant. 25099 25100 Target-specific fundamental types might be new fundamental types or 25101 qualified versions of ordinary fundamental types. Encode new 25102 fundamental types as `u N NAME', where NAME is the name used for 25103 the type in source code, and N is the length of NAME in decimal. 25104 Encode qualified versions of ordinary types as `U N NAME CODE', 25105 where NAME is the name used for the type qualifier in source code, 25106 N is the length of NAME as above, and CODE is the code used to 25107 represent the unqualified version of this type. (See 25108 `write_builtin_type' in `cp/mangle.c' for the list of codes.) In 25109 both cases the spaces are for clarity; do not include any spaces 25110 in your string. 25111 25112 This hook is applied to types prior to typedef resolution. If the 25113 mangled name for a particular type depends only on that type's 25114 main variant, you can perform typedef resolution yourself using 25115 `TYPE_MAIN_VARIANT' before mangling. 25116 25117 The default version of this hook always returns `NULL', which is 25118 appropriate for a target that does not define any new fundamental 25119 types. 25120 25121 25122 File: gccint.info, Node: Type Layout, Next: Registers, Prev: Storage Layout, Up: Target Macros 25123 25124 17.6 Layout of Source Language Data Types 25125 ========================================= 25126 25127 These macros define the sizes and other characteristics of the standard 25128 basic data types used in programs being compiled. Unlike the macros in 25129 the previous section, these apply to specific features of C and related 25130 languages, rather than to fundamental aspects of storage layout. 25131 25132 -- Macro: INT_TYPE_SIZE 25133 A C expression for the size in bits of the type `int' on the 25134 target machine. If you don't define this, the default is one word. 25135 25136 -- Macro: SHORT_TYPE_SIZE 25137 A C expression for the size in bits of the type `short' on the 25138 target machine. If you don't define this, the default is half a 25139 word. (If this would be less than one storage unit, it is rounded 25140 up to one unit.) 25141 25142 -- Macro: LONG_TYPE_SIZE 25143 A C expression for the size in bits of the type `long' on the 25144 target machine. If you don't define this, the default is one word. 25145 25146 -- Macro: ADA_LONG_TYPE_SIZE 25147 On some machines, the size used for the Ada equivalent of the type 25148 `long' by a native Ada compiler differs from that used by C. In 25149 that situation, define this macro to be a C expression to be used 25150 for the size of that type. If you don't define this, the default 25151 is the value of `LONG_TYPE_SIZE'. 25152 25153 -- Macro: LONG_LONG_TYPE_SIZE 25154 A C expression for the size in bits of the type `long long' on the 25155 target machine. If you don't define this, the default is two 25156 words. If you want to support GNU Ada on your machine, the value 25157 of this macro must be at least 64. 25158 25159 -- Macro: CHAR_TYPE_SIZE 25160 A C expression for the size in bits of the type `char' on the 25161 target machine. If you don't define this, the default is 25162 `BITS_PER_UNIT'. 25163 25164 -- Macro: BOOL_TYPE_SIZE 25165 A C expression for the size in bits of the C++ type `bool' and C99 25166 type `_Bool' on the target machine. If you don't define this, and 25167 you probably shouldn't, the default is `CHAR_TYPE_SIZE'. 25168 25169 -- Macro: FLOAT_TYPE_SIZE 25170 A C expression for the size in bits of the type `float' on the 25171 target machine. If you don't define this, the default is one word. 25172 25173 -- Macro: DOUBLE_TYPE_SIZE 25174 A C expression for the size in bits of the type `double' on the 25175 target machine. If you don't define this, the default is two 25176 words. 25177 25178 -- Macro: LONG_DOUBLE_TYPE_SIZE 25179 A C expression for the size in bits of the type `long double' on 25180 the target machine. If you don't define this, the default is two 25181 words. 25182 25183 -- Macro: SHORT_FRACT_TYPE_SIZE 25184 A C expression for the size in bits of the type `short _Fract' on 25185 the target machine. If you don't define this, the default is 25186 `BITS_PER_UNIT'. 25187 25188 -- Macro: FRACT_TYPE_SIZE 25189 A C expression for the size in bits of the type `_Fract' on the 25190 target machine. If you don't define this, the default is 25191 `BITS_PER_UNIT * 2'. 25192 25193 -- Macro: LONG_FRACT_TYPE_SIZE 25194 A C expression for the size in bits of the type `long _Fract' on 25195 the target machine. If you don't define this, the default is 25196 `BITS_PER_UNIT * 4'. 25197 25198 -- Macro: LONG_LONG_FRACT_TYPE_SIZE 25199 A C expression for the size in bits of the type `long long _Fract' 25200 on the target machine. If you don't define this, the default is 25201 `BITS_PER_UNIT * 8'. 25202 25203 -- Macro: SHORT_ACCUM_TYPE_SIZE 25204 A C expression for the size in bits of the type `short _Accum' on 25205 the target machine. If you don't define this, the default is 25206 `BITS_PER_UNIT * 2'. 25207 25208 -- Macro: ACCUM_TYPE_SIZE 25209 A C expression for the size in bits of the type `_Accum' on the 25210 target machine. If you don't define this, the default is 25211 `BITS_PER_UNIT * 4'. 25212 25213 -- Macro: LONG_ACCUM_TYPE_SIZE 25214 A C expression for the size in bits of the type `long _Accum' on 25215 the target machine. If you don't define this, the default is 25216 `BITS_PER_UNIT * 8'. 25217 25218 -- Macro: LONG_LONG_ACCUM_TYPE_SIZE 25219 A C expression for the size in bits of the type `long long _Accum' 25220 on the target machine. If you don't define this, the default is 25221 `BITS_PER_UNIT * 16'. 25222 25223 -- Macro: LIBGCC2_LONG_DOUBLE_TYPE_SIZE 25224 Define this macro if `LONG_DOUBLE_TYPE_SIZE' is not constant or if 25225 you want routines in `libgcc2.a' for a size other than 25226 `LONG_DOUBLE_TYPE_SIZE'. If you don't define this, the default is 25227 `LONG_DOUBLE_TYPE_SIZE'. 25228 25229 -- Macro: LIBGCC2_HAS_DF_MODE 25230 Define this macro if neither `LIBGCC2_DOUBLE_TYPE_SIZE' nor 25231 `LIBGCC2_LONG_DOUBLE_TYPE_SIZE' is `DFmode' but you want `DFmode' 25232 routines in `libgcc2.a' anyway. If you don't define this and 25233 either `LIBGCC2_DOUBLE_TYPE_SIZE' or 25234 `LIBGCC2_LONG_DOUBLE_TYPE_SIZE' is 64 then the default is 1, 25235 otherwise it is 0. 25236 25237 -- Macro: LIBGCC2_HAS_XF_MODE 25238 Define this macro if `LIBGCC2_LONG_DOUBLE_TYPE_SIZE' is not 25239 `XFmode' but you want `XFmode' routines in `libgcc2.a' anyway. If 25240 you don't define this and `LIBGCC2_LONG_DOUBLE_TYPE_SIZE' is 80 25241 then the default is 1, otherwise it is 0. 25242 25243 -- Macro: LIBGCC2_HAS_TF_MODE 25244 Define this macro if `LIBGCC2_LONG_DOUBLE_TYPE_SIZE' is not 25245 `TFmode' but you want `TFmode' routines in `libgcc2.a' anyway. If 25246 you don't define this and `LIBGCC2_LONG_DOUBLE_TYPE_SIZE' is 128 25247 then the default is 1, otherwise it is 0. 25248 25249 -- Macro: SF_SIZE 25250 -- Macro: DF_SIZE 25251 -- Macro: XF_SIZE 25252 -- Macro: TF_SIZE 25253 Define these macros to be the size in bits of the mantissa of 25254 `SFmode', `DFmode', `XFmode' and `TFmode' values, if the defaults 25255 in `libgcc2.h' are inappropriate. By default, `FLT_MANT_DIG' is 25256 used for `SF_SIZE', `LDBL_MANT_DIG' for `XF_SIZE' and `TF_SIZE', 25257 and `DBL_MANT_DIG' or `LDBL_MANT_DIG' for `DF_SIZE' according to 25258 whether `LIBGCC2_DOUBLE_TYPE_SIZE' or 25259 `LIBGCC2_LONG_DOUBLE_TYPE_SIZE' is 64. 25260 25261 -- Macro: TARGET_FLT_EVAL_METHOD 25262 A C expression for the value for `FLT_EVAL_METHOD' in `float.h', 25263 assuming, if applicable, that the floating-point control word is 25264 in its default state. If you do not define this macro the value of 25265 `FLT_EVAL_METHOD' will be zero. 25266 25267 -- Macro: WIDEST_HARDWARE_FP_SIZE 25268 A C expression for the size in bits of the widest floating-point 25269 format supported by the hardware. If you define this macro, you 25270 must specify a value less than or equal to the value of 25271 `LONG_DOUBLE_TYPE_SIZE'. If you do not define this macro, the 25272 value of `LONG_DOUBLE_TYPE_SIZE' is the default. 25273 25274 -- Macro: DEFAULT_SIGNED_CHAR 25275 An expression whose value is 1 or 0, according to whether the type 25276 `char' should be signed or unsigned by default. The user can 25277 always override this default with the options `-fsigned-char' and 25278 `-funsigned-char'. 25279 25280 -- Target Hook: bool TARGET_DEFAULT_SHORT_ENUMS (void) 25281 This target hook should return true if the compiler should give an 25282 `enum' type only as many bytes as it takes to represent the range 25283 of possible values of that type. It should return false if all 25284 `enum' types should be allocated like `int'. 25285 25286 The default is to return false. 25287 25288 -- Macro: SIZE_TYPE 25289 A C expression for a string describing the name of the data type 25290 to use for size values. The typedef name `size_t' is defined 25291 using the contents of the string. 25292 25293 The string can contain more than one keyword. If so, separate 25294 them with spaces, and write first any length keyword, then 25295 `unsigned' if appropriate, and finally `int'. The string must 25296 exactly match one of the data type names defined in the function 25297 `init_decl_processing' in the file `c-decl.c'. You may not omit 25298 `int' or change the order--that would cause the compiler to crash 25299 on startup. 25300 25301 If you don't define this macro, the default is `"long unsigned 25302 int"'. 25303 25304 -- Macro: PTRDIFF_TYPE 25305 A C expression for a string describing the name of the data type 25306 to use for the result of subtracting two pointers. The typedef 25307 name `ptrdiff_t' is defined using the contents of the string. See 25308 `SIZE_TYPE' above for more information. 25309 25310 If you don't define this macro, the default is `"long int"'. 25311 25312 -- Macro: WCHAR_TYPE 25313 A C expression for a string describing the name of the data type 25314 to use for wide characters. The typedef name `wchar_t' is defined 25315 using the contents of the string. See `SIZE_TYPE' above for more 25316 information. 25317 25318 If you don't define this macro, the default is `"int"'. 25319 25320 -- Macro: WCHAR_TYPE_SIZE 25321 A C expression for the size in bits of the data type for wide 25322 characters. This is used in `cpp', which cannot make use of 25323 `WCHAR_TYPE'. 25324 25325 -- Macro: WINT_TYPE 25326 A C expression for a string describing the name of the data type to 25327 use for wide characters passed to `printf' and returned from 25328 `getwc'. The typedef name `wint_t' is defined using the contents 25329 of the string. See `SIZE_TYPE' above for more information. 25330 25331 If you don't define this macro, the default is `"unsigned int"'. 25332 25333 -- Macro: INTMAX_TYPE 25334 A C expression for a string describing the name of the data type 25335 that can represent any value of any standard or extended signed 25336 integer type. The typedef name `intmax_t' is defined using the 25337 contents of the string. See `SIZE_TYPE' above for more 25338 information. 25339 25340 If you don't define this macro, the default is the first of 25341 `"int"', `"long int"', or `"long long int"' that has as much 25342 precision as `long long int'. 25343 25344 -- Macro: UINTMAX_TYPE 25345 A C expression for a string describing the name of the data type 25346 that can represent any value of any standard or extended unsigned 25347 integer type. The typedef name `uintmax_t' is defined using the 25348 contents of the string. See `SIZE_TYPE' above for more 25349 information. 25350 25351 If you don't define this macro, the default is the first of 25352 `"unsigned int"', `"long unsigned int"', or `"long long unsigned 25353 int"' that has as much precision as `long long unsigned int'. 25354 25355 -- Macro: TARGET_PTRMEMFUNC_VBIT_LOCATION 25356 The C++ compiler represents a pointer-to-member-function with a 25357 struct that looks like: 25358 25359 struct { 25360 union { 25361 void (*fn)(); 25362 ptrdiff_t vtable_index; 25363 }; 25364 ptrdiff_t delta; 25365 }; 25366 25367 The C++ compiler must use one bit to indicate whether the function 25368 that will be called through a pointer-to-member-function is 25369 virtual. Normally, we assume that the low-order bit of a function 25370 pointer must always be zero. Then, by ensuring that the 25371 vtable_index is odd, we can distinguish which variant of the union 25372 is in use. But, on some platforms function pointers can be odd, 25373 and so this doesn't work. In that case, we use the low-order bit 25374 of the `delta' field, and shift the remainder of the `delta' field 25375 to the left. 25376 25377 GCC will automatically make the right selection about where to 25378 store this bit using the `FUNCTION_BOUNDARY' setting for your 25379 platform. However, some platforms such as ARM/Thumb have 25380 `FUNCTION_BOUNDARY' set such that functions always start at even 25381 addresses, but the lowest bit of pointers to functions indicate 25382 whether the function at that address is in ARM or Thumb mode. If 25383 this is the case of your architecture, you should define this 25384 macro to `ptrmemfunc_vbit_in_delta'. 25385 25386 In general, you should not have to define this macro. On 25387 architectures in which function addresses are always even, 25388 according to `FUNCTION_BOUNDARY', GCC will automatically define 25389 this macro to `ptrmemfunc_vbit_in_pfn'. 25390 25391 -- Macro: TARGET_VTABLE_USES_DESCRIPTORS 25392 Normally, the C++ compiler uses function pointers in vtables. This 25393 macro allows the target to change to use "function descriptors" 25394 instead. Function descriptors are found on targets for whom a 25395 function pointer is actually a small data structure. Normally the 25396 data structure consists of the actual code address plus a data 25397 pointer to which the function's data is relative. 25398 25399 If vtables are used, the value of this macro should be the number 25400 of words that the function descriptor occupies. 25401 25402 -- Macro: TARGET_VTABLE_ENTRY_ALIGN 25403 By default, the vtable entries are void pointers, the so the 25404 alignment is the same as pointer alignment. The value of this 25405 macro specifies the alignment of the vtable entry in bits. It 25406 should be defined only when special alignment is necessary. */ 25407 25408 -- Macro: TARGET_VTABLE_DATA_ENTRY_DISTANCE 25409 There are a few non-descriptor entries in the vtable at offsets 25410 below zero. If these entries must be padded (say, to preserve the 25411 alignment specified by `TARGET_VTABLE_ENTRY_ALIGN'), set this to 25412 the number of words in each data entry. 25413 25414 25415 File: gccint.info, Node: Registers, Next: Register Classes, Prev: Type Layout, Up: Target Macros 25416 25417 17.7 Register Usage 25418 =================== 25419 25420 This section explains how to describe what registers the target machine 25421 has, and how (in general) they can be used. 25422 25423 The description of which registers a specific instruction can use is 25424 done with register classes; see *Note Register Classes::. For 25425 information on using registers to access a stack frame, see *Note Frame 25426 Registers::. For passing values in registers, see *Note Register 25427 Arguments::. For returning values in registers, see *Note Scalar 25428 Return::. 25429 25430 * Menu: 25431 25432 * Register Basics:: Number and kinds of registers. 25433 * Allocation Order:: Order in which registers are allocated. 25434 * Values in Registers:: What kinds of values each reg can hold. 25435 * Leaf Functions:: Renumbering registers for leaf functions. 25436 * Stack Registers:: Handling a register stack such as 80387. 25437 25438 25439 File: gccint.info, Node: Register Basics, Next: Allocation Order, Up: Registers 25440 25441 17.7.1 Basic Characteristics of Registers 25442 ----------------------------------------- 25443 25444 Registers have various characteristics. 25445 25446 -- Macro: FIRST_PSEUDO_REGISTER 25447 Number of hardware registers known to the compiler. They receive 25448 numbers 0 through `FIRST_PSEUDO_REGISTER-1'; thus, the first 25449 pseudo register's number really is assigned the number 25450 `FIRST_PSEUDO_REGISTER'. 25451 25452 -- Macro: FIXED_REGISTERS 25453 An initializer that says which registers are used for fixed 25454 purposes all throughout the compiled code and are therefore not 25455 available for general allocation. These would include the stack 25456 pointer, the frame pointer (except on machines where that can be 25457 used as a general register when no frame pointer is needed), the 25458 program counter on machines where that is considered one of the 25459 addressable registers, and any other numbered register with a 25460 standard use. 25461 25462 This information is expressed as a sequence of numbers, separated 25463 by commas and surrounded by braces. The Nth number is 1 if 25464 register N is fixed, 0 otherwise. 25465 25466 The table initialized from this macro, and the table initialized by 25467 the following one, may be overridden at run time either 25468 automatically, by the actions of the macro 25469 `CONDITIONAL_REGISTER_USAGE', or by the user with the command 25470 options `-ffixed-REG', `-fcall-used-REG' and `-fcall-saved-REG'. 25471 25472 -- Macro: CALL_USED_REGISTERS 25473 Like `FIXED_REGISTERS' but has 1 for each register that is 25474 clobbered (in general) by function calls as well as for fixed 25475 registers. This macro therefore identifies the registers that are 25476 not available for general allocation of values that must live 25477 across function calls. 25478 25479 If a register has 0 in `CALL_USED_REGISTERS', the compiler 25480 automatically saves it on function entry and restores it on 25481 function exit, if the register is used within the function. 25482 25483 -- Macro: CALL_REALLY_USED_REGISTERS 25484 Like `CALL_USED_REGISTERS' except this macro doesn't require that 25485 the entire set of `FIXED_REGISTERS' be included. 25486 (`CALL_USED_REGISTERS' must be a superset of `FIXED_REGISTERS'). 25487 This macro is optional. If not specified, it defaults to the value 25488 of `CALL_USED_REGISTERS'. 25489 25490 -- Macro: HARD_REGNO_CALL_PART_CLOBBERED (REGNO, MODE) 25491 A C expression that is nonzero if it is not permissible to store a 25492 value of mode MODE in hard register number REGNO across a call 25493 without some part of it being clobbered. For most machines this 25494 macro need not be defined. It is only required for machines that 25495 do not preserve the entire contents of a register across a call. 25496 25497 -- Macro: CONDITIONAL_REGISTER_USAGE 25498 Zero or more C statements that may conditionally modify five 25499 variables `fixed_regs', `call_used_regs', `global_regs', 25500 `reg_names', and `reg_class_contents', to take into account any 25501 dependence of these register sets on target flags. The first three 25502 of these are of type `char []' (interpreted as Boolean vectors). 25503 `global_regs' is a `const char *[]', and `reg_class_contents' is a 25504 `HARD_REG_SET'. Before the macro is called, `fixed_regs', 25505 `call_used_regs', `reg_class_contents', and `reg_names' have been 25506 initialized from `FIXED_REGISTERS', `CALL_USED_REGISTERS', 25507 `REG_CLASS_CONTENTS', and `REGISTER_NAMES', respectively. 25508 `global_regs' has been cleared, and any `-ffixed-REG', 25509 `-fcall-used-REG' and `-fcall-saved-REG' command options have been 25510 applied. 25511 25512 You need not define this macro if it has no work to do. 25513 25514 If the usage of an entire class of registers depends on the target 25515 flags, you may indicate this to GCC by using this macro to modify 25516 `fixed_regs' and `call_used_regs' to 1 for each of the registers 25517 in the classes which should not be used by GCC. Also define the 25518 macro `REG_CLASS_FROM_LETTER' / `REG_CLASS_FROM_CONSTRAINT' to 25519 return `NO_REGS' if it is called with a letter for a class that 25520 shouldn't be used. 25521 25522 (However, if this class is not included in `GENERAL_REGS' and all 25523 of the insn patterns whose constraints permit this class are 25524 controlled by target switches, then GCC will automatically avoid 25525 using these registers when the target switches are opposed to 25526 them.) 25527 25528 -- Macro: INCOMING_REGNO (OUT) 25529 Define this macro if the target machine has register windows. 25530 This C expression returns the register number as seen by the 25531 called function corresponding to the register number OUT as seen 25532 by the calling function. Return OUT if register number OUT is not 25533 an outbound register. 25534 25535 -- Macro: OUTGOING_REGNO (IN) 25536 Define this macro if the target machine has register windows. 25537 This C expression returns the register number as seen by the 25538 calling function corresponding to the register number IN as seen 25539 by the called function. Return IN if register number IN is not an 25540 inbound register. 25541 25542 -- Macro: LOCAL_REGNO (REGNO) 25543 Define this macro if the target machine has register windows. 25544 This C expression returns true if the register is call-saved but 25545 is in the register window. Unlike most call-saved registers, such 25546 registers need not be explicitly restored on function exit or 25547 during non-local gotos. 25548 25549 -- Macro: PC_REGNUM 25550 If the program counter has a register number, define this as that 25551 register number. Otherwise, do not define it. 25552 25553 25554 File: gccint.info, Node: Allocation Order, Next: Values in Registers, Prev: Register Basics, Up: Registers 25555 25556 17.7.2 Order of Allocation of Registers 25557 --------------------------------------- 25558 25559 Registers are allocated in order. 25560 25561 -- Macro: REG_ALLOC_ORDER 25562 If defined, an initializer for a vector of integers, containing the 25563 numbers of hard registers in the order in which GCC should prefer 25564 to use them (from most preferred to least). 25565 25566 If this macro is not defined, registers are used lowest numbered 25567 first (all else being equal). 25568 25569 One use of this macro is on machines where the highest numbered 25570 registers must always be saved and the save-multiple-registers 25571 instruction supports only sequences of consecutive registers. On 25572 such machines, define `REG_ALLOC_ORDER' to be an initializer that 25573 lists the highest numbered allocable register first. 25574 25575 -- Macro: ORDER_REGS_FOR_LOCAL_ALLOC 25576 A C statement (sans semicolon) to choose the order in which to 25577 allocate hard registers for pseudo-registers local to a basic 25578 block. 25579 25580 Store the desired register order in the array `reg_alloc_order'. 25581 Element 0 should be the register to allocate first; element 1, the 25582 next register; and so on. 25583 25584 The macro body should not assume anything about the contents of 25585 `reg_alloc_order' before execution of the macro. 25586 25587 On most machines, it is not necessary to define this macro. 25588 25589 -- Macro: IRA_HARD_REGNO_ADD_COST_MULTIPLIER (REGNO) 25590 In some case register allocation order is not enough for the 25591 Integrated Register Allocator (IRA) to generate a good code. If 25592 this macro is defined, it should return a floating point value 25593 based on REGNO. The cost of using REGNO for a pseudo will be 25594 increased by approximately the pseudo's usage frequency times the 25595 value returned by this macro. Not defining this macro is 25596 equivalent to having it always return `0.0'. 25597 25598 On most machines, it is not necessary to define this macro. 25599 25600 25601 File: gccint.info, Node: Values in Registers, Next: Leaf Functions, Prev: Allocation Order, Up: Registers 25602 25603 17.7.3 How Values Fit in Registers 25604 ---------------------------------- 25605 25606 This section discusses the macros that describe which kinds of values 25607 (specifically, which machine modes) each register can hold, and how many 25608 consecutive registers are needed for a given mode. 25609 25610 -- Macro: HARD_REGNO_NREGS (REGNO, MODE) 25611 A C expression for the number of consecutive hard registers, 25612 starting at register number REGNO, required to hold a value of mode 25613 MODE. This macro must never return zero, even if a register 25614 cannot hold the requested mode - indicate that with 25615 HARD_REGNO_MODE_OK and/or CANNOT_CHANGE_MODE_CLASS instead. 25616 25617 On a machine where all registers are exactly one word, a suitable 25618 definition of this macro is 25619 25620 #define HARD_REGNO_NREGS(REGNO, MODE) \ 25621 ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) \ 25622 / UNITS_PER_WORD) 25623 25624 -- Macro: HARD_REGNO_NREGS_HAS_PADDING (REGNO, MODE) 25625 A C expression that is nonzero if a value of mode MODE, stored in 25626 memory, ends with padding that causes it to take up more space than 25627 in registers starting at register number REGNO (as determined by 25628 multiplying GCC's notion of the size of the register when 25629 containing this mode by the number of registers returned by 25630 `HARD_REGNO_NREGS'). By default this is zero. 25631 25632 For example, if a floating-point value is stored in three 32-bit 25633 registers but takes up 128 bits in memory, then this would be 25634 nonzero. 25635 25636 This macros only needs to be defined if there are cases where 25637 `subreg_get_info' would otherwise wrongly determine that a 25638 `subreg' can be represented by an offset to the register number, 25639 when in fact such a `subreg' would contain some of the padding not 25640 stored in registers and so not be representable. 25641 25642 -- Macro: HARD_REGNO_NREGS_WITH_PADDING (REGNO, MODE) 25643 For values of REGNO and MODE for which 25644 `HARD_REGNO_NREGS_HAS_PADDING' returns nonzero, a C expression 25645 returning the greater number of registers required to hold the 25646 value including any padding. In the example above, the value 25647 would be four. 25648 25649 -- Macro: REGMODE_NATURAL_SIZE (MODE) 25650 Define this macro if the natural size of registers that hold values 25651 of mode MODE is not the word size. It is a C expression that 25652 should give the natural size in bytes for the specified mode. It 25653 is used by the register allocator to try to optimize its results. 25654 This happens for example on SPARC 64-bit where the natural size of 25655 floating-point registers is still 32-bit. 25656 25657 -- Macro: HARD_REGNO_MODE_OK (REGNO, MODE) 25658 A C expression that is nonzero if it is permissible to store a 25659 value of mode MODE in hard register number REGNO (or in several 25660 registers starting with that one). For a machine where all 25661 registers are equivalent, a suitable definition is 25662 25663 #define HARD_REGNO_MODE_OK(REGNO, MODE) 1 25664 25665 You need not include code to check for the numbers of fixed 25666 registers, because the allocation mechanism considers them to be 25667 always occupied. 25668 25669 On some machines, double-precision values must be kept in even/odd 25670 register pairs. You can implement that by defining this macro to 25671 reject odd register numbers for such modes. 25672 25673 The minimum requirement for a mode to be OK in a register is that 25674 the `movMODE' instruction pattern support moves between the 25675 register and other hard register in the same class and that moving 25676 a value into the register and back out not alter it. 25677 25678 Since the same instruction used to move `word_mode' will work for 25679 all narrower integer modes, it is not necessary on any machine for 25680 `HARD_REGNO_MODE_OK' to distinguish between these modes, provided 25681 you define patterns `movhi', etc., to take advantage of this. This 25682 is useful because of the interaction between `HARD_REGNO_MODE_OK' 25683 and `MODES_TIEABLE_P'; it is very desirable for all integer modes 25684 to be tieable. 25685 25686 Many machines have special registers for floating point arithmetic. 25687 Often people assume that floating point machine modes are allowed 25688 only in floating point registers. This is not true. Any 25689 registers that can hold integers can safely _hold_ a floating 25690 point machine mode, whether or not floating arithmetic can be done 25691 on it in those registers. Integer move instructions can be used 25692 to move the values. 25693 25694 On some machines, though, the converse is true: fixed-point machine 25695 modes may not go in floating registers. This is true if the 25696 floating registers normalize any value stored in them, because 25697 storing a non-floating value there would garble it. In this case, 25698 `HARD_REGNO_MODE_OK' should reject fixed-point machine modes in 25699 floating registers. But if the floating registers do not 25700 automatically normalize, if you can store any bit pattern in one 25701 and retrieve it unchanged without a trap, then any machine mode 25702 may go in a floating register, so you can define this macro to say 25703 so. 25704 25705 The primary significance of special floating registers is rather 25706 that they are the registers acceptable in floating point arithmetic 25707 instructions. However, this is of no concern to 25708 `HARD_REGNO_MODE_OK'. You handle it by writing the proper 25709 constraints for those instructions. 25710 25711 On some machines, the floating registers are especially slow to 25712 access, so that it is better to store a value in a stack frame 25713 than in such a register if floating point arithmetic is not being 25714 done. As long as the floating registers are not in class 25715 `GENERAL_REGS', they will not be used unless some pattern's 25716 constraint asks for one. 25717 25718 -- Macro: HARD_REGNO_RENAME_OK (FROM, TO) 25719 A C expression that is nonzero if it is OK to rename a hard 25720 register FROM to another hard register TO. 25721 25722 One common use of this macro is to prevent renaming of a register 25723 to another register that is not saved by a prologue in an interrupt 25724 handler. 25725 25726 The default is always nonzero. 25727 25728 -- Macro: MODES_TIEABLE_P (MODE1, MODE2) 25729 A C expression that is nonzero if a value of mode MODE1 is 25730 accessible in mode MODE2 without copying. 25731 25732 If `HARD_REGNO_MODE_OK (R, MODE1)' and `HARD_REGNO_MODE_OK (R, 25733 MODE2)' are always the same for any R, then `MODES_TIEABLE_P 25734 (MODE1, MODE2)' should be nonzero. If they differ for any R, you 25735 should define this macro to return zero unless some other 25736 mechanism ensures the accessibility of the value in a narrower 25737 mode. 25738 25739 You should define this macro to return nonzero in as many cases as 25740 possible since doing so will allow GCC to perform better register 25741 allocation. 25742 25743 -- Target Hook: bool TARGET_HARD_REGNO_SCRATCH_OK (unsigned int REGNO) 25744 This target hook should return `true' if it is OK to use a hard 25745 register REGNO as scratch reg in peephole2. 25746 25747 One common use of this macro is to prevent using of a register that 25748 is not saved by a prologue in an interrupt handler. 25749 25750 The default version of this hook always returns `true'. 25751 25752 -- Macro: AVOID_CCMODE_COPIES 25753 Define this macro if the compiler should avoid copies to/from 25754 `CCmode' registers. You should only define this macro if support 25755 for copying to/from `CCmode' is incomplete. 25756 25757 25758 File: gccint.info, Node: Leaf Functions, Next: Stack Registers, Prev: Values in Registers, Up: Registers 25759 25760 17.7.4 Handling Leaf Functions 25761 ------------------------------ 25762 25763 On some machines, a leaf function (i.e., one which makes no calls) can 25764 run more efficiently if it does not make its own register window. 25765 Often this means it is required to receive its arguments in the 25766 registers where they are passed by the caller, instead of the registers 25767 where they would normally arrive. 25768 25769 The special treatment for leaf functions generally applies only when 25770 other conditions are met; for example, often they may use only those 25771 registers for its own variables and temporaries. We use the term "leaf 25772 function" to mean a function that is suitable for this special 25773 handling, so that functions with no calls are not necessarily "leaf 25774 functions". 25775 25776 GCC assigns register numbers before it knows whether the function is 25777 suitable for leaf function treatment. So it needs to renumber the 25778 registers in order to output a leaf function. The following macros 25779 accomplish this. 25780 25781 -- Macro: LEAF_REGISTERS 25782 Name of a char vector, indexed by hard register number, which 25783 contains 1 for a register that is allowable in a candidate for leaf 25784 function treatment. 25785 25786 If leaf function treatment involves renumbering the registers, 25787 then the registers marked here should be the ones before 25788 renumbering--those that GCC would ordinarily allocate. The 25789 registers which will actually be used in the assembler code, after 25790 renumbering, should not be marked with 1 in this vector. 25791 25792 Define this macro only if the target machine offers a way to 25793 optimize the treatment of leaf functions. 25794 25795 -- Macro: LEAF_REG_REMAP (REGNO) 25796 A C expression whose value is the register number to which REGNO 25797 should be renumbered, when a function is treated as a leaf 25798 function. 25799 25800 If REGNO is a register number which should not appear in a leaf 25801 function before renumbering, then the expression should yield -1, 25802 which will cause the compiler to abort. 25803 25804 Define this macro only if the target machine offers a way to 25805 optimize the treatment of leaf functions, and registers need to be 25806 renumbered to do this. 25807 25808 `TARGET_ASM_FUNCTION_PROLOGUE' and `TARGET_ASM_FUNCTION_EPILOGUE' must 25809 usually treat leaf functions specially. They can test the C variable 25810 `current_function_is_leaf' which is nonzero for leaf functions. 25811 `current_function_is_leaf' is set prior to local register allocation 25812 and is valid for the remaining compiler passes. They can also test the 25813 C variable `current_function_uses_only_leaf_regs' which is nonzero for 25814 leaf functions which only use leaf registers. 25815 `current_function_uses_only_leaf_regs' is valid after all passes that 25816 modify the instructions have been run and is only useful if 25817 `LEAF_REGISTERS' is defined. 25818 25819 25820 File: gccint.info, Node: Stack Registers, Prev: Leaf Functions, Up: Registers 25821 25822 17.7.5 Registers That Form a Stack 25823 ---------------------------------- 25824 25825 There are special features to handle computers where some of the 25826 "registers" form a stack. Stack registers are normally written by 25827 pushing onto the stack, and are numbered relative to the top of the 25828 stack. 25829 25830 Currently, GCC can only handle one group of stack-like registers, and 25831 they must be consecutively numbered. Furthermore, the existing support 25832 for stack-like registers is specific to the 80387 floating point 25833 coprocessor. If you have a new architecture that uses stack-like 25834 registers, you will need to do substantial work on `reg-stack.c' and 25835 write your machine description to cooperate with it, as well as 25836 defining these macros. 25837 25838 -- Macro: STACK_REGS 25839 Define this if the machine has any stack-like registers. 25840 25841 -- Macro: FIRST_STACK_REG 25842 The number of the first stack-like register. This one is the top 25843 of the stack. 25844 25845 -- Macro: LAST_STACK_REG 25846 The number of the last stack-like register. This one is the 25847 bottom of the stack. 25848 25849 25850 File: gccint.info, Node: Register Classes, Next: Old Constraints, Prev: Registers, Up: Target Macros 25851 25852 17.8 Register Classes 25853 ===================== 25854 25855 On many machines, the numbered registers are not all equivalent. For 25856 example, certain registers may not be allowed for indexed addressing; 25857 certain registers may not be allowed in some instructions. These 25858 machine restrictions are described to the compiler using "register 25859 classes". 25860 25861 You define a number of register classes, giving each one a name and 25862 saying which of the registers belong to it. Then you can specify 25863 register classes that are allowed as operands to particular instruction 25864 patterns. 25865 25866 In general, each register will belong to several classes. In fact, one 25867 class must be named `ALL_REGS' and contain all the registers. Another 25868 class must be named `NO_REGS' and contain no registers. Often the 25869 union of two classes will be another class; however, this is not 25870 required. 25871 25872 One of the classes must be named `GENERAL_REGS'. There is nothing 25873 terribly special about the name, but the operand constraint letters `r' 25874 and `g' specify this class. If `GENERAL_REGS' is the same as 25875 `ALL_REGS', just define it as a macro which expands to `ALL_REGS'. 25876 25877 Order the classes so that if class X is contained in class Y then X 25878 has a lower class number than Y. 25879 25880 The way classes other than `GENERAL_REGS' are specified in operand 25881 constraints is through machine-dependent operand constraint letters. 25882 You can define such letters to correspond to various classes, then use 25883 them in operand constraints. 25884 25885 You should define a class for the union of two classes whenever some 25886 instruction allows both classes. For example, if an instruction allows 25887 either a floating point (coprocessor) register or a general register 25888 for a certain operand, you should define a class `FLOAT_OR_GENERAL_REGS' 25889 which includes both of them. Otherwise you will get suboptimal code. 25890 25891 You must also specify certain redundant information about the register 25892 classes: for each class, which classes contain it and which ones are 25893 contained in it; for each pair of classes, the largest class contained 25894 in their union. 25895 25896 When a value occupying several consecutive registers is expected in a 25897 certain class, all the registers used must belong to that class. 25898 Therefore, register classes cannot be used to enforce a requirement for 25899 a register pair to start with an even-numbered register. The way to 25900 specify this requirement is with `HARD_REGNO_MODE_OK'. 25901 25902 Register classes used for input-operands of bitwise-and or shift 25903 instructions have a special requirement: each such class must have, for 25904 each fixed-point machine mode, a subclass whose registers can transfer 25905 that mode to or from memory. For example, on some machines, the 25906 operations for single-byte values (`QImode') are limited to certain 25907 registers. When this is so, each register class that is used in a 25908 bitwise-and or shift instruction must have a subclass consisting of 25909 registers from which single-byte values can be loaded or stored. This 25910 is so that `PREFERRED_RELOAD_CLASS' can always have a possible value to 25911 return. 25912 25913 -- Data type: enum reg_class 25914 An enumerated type that must be defined with all the register 25915 class names as enumerated values. `NO_REGS' must be first. 25916 `ALL_REGS' must be the last register class, followed by one more 25917 enumerated value, `LIM_REG_CLASSES', which is not a register class 25918 but rather tells how many classes there are. 25919 25920 Each register class has a number, which is the value of casting 25921 the class name to type `int'. The number serves as an index in 25922 many of the tables described below. 25923 25924 -- Macro: N_REG_CLASSES 25925 The number of distinct register classes, defined as follows: 25926 25927 #define N_REG_CLASSES (int) LIM_REG_CLASSES 25928 25929 -- Macro: REG_CLASS_NAMES 25930 An initializer containing the names of the register classes as C 25931 string constants. These names are used in writing some of the 25932 debugging dumps. 25933 25934 -- Macro: REG_CLASS_CONTENTS 25935 An initializer containing the contents of the register classes, as 25936 integers which are bit masks. The Nth integer specifies the 25937 contents of class N. The way the integer MASK is interpreted is 25938 that register R is in the class if `MASK & (1 << R)' is 1. 25939 25940 When the machine has more than 32 registers, an integer does not 25941 suffice. Then the integers are replaced by sub-initializers, 25942 braced groupings containing several integers. Each 25943 sub-initializer must be suitable as an initializer for the type 25944 `HARD_REG_SET' which is defined in `hard-reg-set.h'. In this 25945 situation, the first integer in each sub-initializer corresponds to 25946 registers 0 through 31, the second integer to registers 32 through 25947 63, and so on. 25948 25949 -- Macro: REGNO_REG_CLASS (REGNO) 25950 A C expression whose value is a register class containing hard 25951 register REGNO. In general there is more than one such class; 25952 choose a class which is "minimal", meaning that no smaller class 25953 also contains the register. 25954 25955 -- Macro: BASE_REG_CLASS 25956 A macro whose definition is the name of the class to which a valid 25957 base register must belong. A base register is one used in an 25958 address which is the register value plus a displacement. 25959 25960 -- Macro: MODE_BASE_REG_CLASS (MODE) 25961 This is a variation of the `BASE_REG_CLASS' macro which allows the 25962 selection of a base register in a mode dependent manner. If MODE 25963 is VOIDmode then it should return the same value as 25964 `BASE_REG_CLASS'. 25965 25966 -- Macro: MODE_BASE_REG_REG_CLASS (MODE) 25967 A C expression whose value is the register class to which a valid 25968 base register must belong in order to be used in a base plus index 25969 register address. You should define this macro if base plus index 25970 addresses have different requirements than other base register 25971 uses. 25972 25973 -- Macro: MODE_CODE_BASE_REG_CLASS (MODE, OUTER_CODE, INDEX_CODE) 25974 A C expression whose value is the register class to which a valid 25975 base register must belong. OUTER_CODE and INDEX_CODE define the 25976 context in which the base register occurs. OUTER_CODE is the code 25977 of the immediately enclosing expression (`MEM' for the top level 25978 of an address, `ADDRESS' for something that occurs in an 25979 `address_operand'). INDEX_CODE is the code of the corresponding 25980 index expression if OUTER_CODE is `PLUS'; `SCRATCH' otherwise. 25981 25982 -- Macro: INDEX_REG_CLASS 25983 A macro whose definition is the name of the class to which a valid 25984 index register must belong. An index register is one used in an 25985 address where its value is either multiplied by a scale factor or 25986 added to another register (as well as added to a displacement). 25987 25988 -- Macro: REGNO_OK_FOR_BASE_P (NUM) 25989 A C expression which is nonzero if register number NUM is suitable 25990 for use as a base register in operand addresses. It may be either 25991 a suitable hard register or a pseudo register that has been 25992 allocated such a hard register. 25993 25994 -- Macro: REGNO_MODE_OK_FOR_BASE_P (NUM, MODE) 25995 A C expression that is just like `REGNO_OK_FOR_BASE_P', except that 25996 that expression may examine the mode of the memory reference in 25997 MODE. You should define this macro if the mode of the memory 25998 reference affects whether a register may be used as a base 25999 register. If you define this macro, the compiler will use it 26000 instead of `REGNO_OK_FOR_BASE_P'. The mode may be `VOIDmode' for 26001 addresses that appear outside a `MEM', i.e., as an 26002 `address_operand'. 26003 26004 26005 -- Macro: REGNO_MODE_OK_FOR_REG_BASE_P (NUM, MODE) 26006 A C expression which is nonzero if register number NUM is suitable 26007 for use as a base register in base plus index operand addresses, 26008 accessing memory in mode MODE. It may be either a suitable hard 26009 register or a pseudo register that has been allocated such a hard 26010 register. You should define this macro if base plus index 26011 addresses have different requirements than other base register 26012 uses. 26013 26014 Use of this macro is deprecated; please use the more general 26015 `REGNO_MODE_CODE_OK_FOR_BASE_P'. 26016 26017 -- Macro: REGNO_MODE_CODE_OK_FOR_BASE_P (NUM, MODE, OUTER_CODE, 26018 INDEX_CODE) 26019 A C expression that is just like `REGNO_MODE_OK_FOR_BASE_P', except 26020 that that expression may examine the context in which the register 26021 appears in the memory reference. OUTER_CODE is the code of the 26022 immediately enclosing expression (`MEM' if at the top level of the 26023 address, `ADDRESS' for something that occurs in an 26024 `address_operand'). INDEX_CODE is the code of the corresponding 26025 index expression if OUTER_CODE is `PLUS'; `SCRATCH' otherwise. 26026 The mode may be `VOIDmode' for addresses that appear outside a 26027 `MEM', i.e., as an `address_operand'. 26028 26029 -- Macro: REGNO_OK_FOR_INDEX_P (NUM) 26030 A C expression which is nonzero if register number NUM is suitable 26031 for use as an index register in operand addresses. It may be 26032 either a suitable hard register or a pseudo register that has been 26033 allocated such a hard register. 26034 26035 The difference between an index register and a base register is 26036 that the index register may be scaled. If an address involves the 26037 sum of two registers, neither one of them scaled, then either one 26038 may be labeled the "base" and the other the "index"; but whichever 26039 labeling is used must fit the machine's constraints of which 26040 registers may serve in each capacity. The compiler will try both 26041 labelings, looking for one that is valid, and will reload one or 26042 both registers only if neither labeling works. 26043 26044 -- Macro: PREFERRED_RELOAD_CLASS (X, CLASS) 26045 A C expression that places additional restrictions on the register 26046 class to use when it is necessary to copy value X into a register 26047 in class CLASS. The value is a register class; perhaps CLASS, or 26048 perhaps another, smaller class. On many machines, the following 26049 definition is safe: 26050 26051 #define PREFERRED_RELOAD_CLASS(X,CLASS) CLASS 26052 26053 Sometimes returning a more restrictive class makes better code. 26054 For example, on the 68000, when X is an integer constant that is 26055 in range for a `moveq' instruction, the value of this macro is 26056 always `DATA_REGS' as long as CLASS includes the data registers. 26057 Requiring a data register guarantees that a `moveq' will be used. 26058 26059 One case where `PREFERRED_RELOAD_CLASS' must not return CLASS is 26060 if X is a legitimate constant which cannot be loaded into some 26061 register class. By returning `NO_REGS' you can force X into a 26062 memory location. For example, rs6000 can load immediate values 26063 into general-purpose registers, but does not have an instruction 26064 for loading an immediate value into a floating-point register, so 26065 `PREFERRED_RELOAD_CLASS' returns `NO_REGS' when X is a 26066 floating-point constant. If the constant can't be loaded into any 26067 kind of register, code generation will be better if 26068 `LEGITIMATE_CONSTANT_P' makes the constant illegitimate instead of 26069 using `PREFERRED_RELOAD_CLASS'. 26070 26071 If an insn has pseudos in it after register allocation, reload 26072 will go through the alternatives and call repeatedly 26073 `PREFERRED_RELOAD_CLASS' to find the best one. Returning 26074 `NO_REGS', in this case, makes reload add a `!' in front of the 26075 constraint: the x86 back-end uses this feature to discourage usage 26076 of 387 registers when math is done in the SSE registers (and vice 26077 versa). 26078 26079 -- Macro: PREFERRED_OUTPUT_RELOAD_CLASS (X, CLASS) 26080 Like `PREFERRED_RELOAD_CLASS', but for output reloads instead of 26081 input reloads. If you don't define this macro, the default is to 26082 use CLASS, unchanged. 26083 26084 You can also use `PREFERRED_OUTPUT_RELOAD_CLASS' to discourage 26085 reload from using some alternatives, like `PREFERRED_RELOAD_CLASS'. 26086 26087 -- Macro: LIMIT_RELOAD_CLASS (MODE, CLASS) 26088 A C expression that places additional restrictions on the register 26089 class to use when it is necessary to be able to hold a value of 26090 mode MODE in a reload register for which class CLASS would 26091 ordinarily be used. 26092 26093 Unlike `PREFERRED_RELOAD_CLASS', this macro should be used when 26094 there are certain modes that simply can't go in certain reload 26095 classes. 26096 26097 The value is a register class; perhaps CLASS, or perhaps another, 26098 smaller class. 26099 26100 Don't define this macro unless the target machine has limitations 26101 which require the macro to do something nontrivial. 26102 26103 -- Target Hook: enum reg_class TARGET_SECONDARY_RELOAD (bool IN_P, rtx 26104 X, enum reg_class RELOAD_CLASS, enum machine_mode 26105 RELOAD_MODE, secondary_reload_info *SRI) 26106 Many machines have some registers that cannot be copied directly 26107 to or from memory or even from other types of registers. An 26108 example is the `MQ' register, which on most machines, can only be 26109 copied to or from general registers, but not memory. Below, we 26110 shall be using the term 'intermediate register' when a move 26111 operation cannot be performed directly, but has to be done by 26112 copying the source into the intermediate register first, and then 26113 copying the intermediate register to the destination. An 26114 intermediate register always has the same mode as source and 26115 destination. Since it holds the actual value being copied, reload 26116 might apply optimizations to re-use an intermediate register and 26117 eliding the copy from the source when it can determine that the 26118 intermediate register still holds the required value. 26119 26120 Another kind of secondary reload is required on some machines which 26121 allow copying all registers to and from memory, but require a 26122 scratch register for stores to some memory locations (e.g., those 26123 with symbolic address on the RT, and those with certain symbolic 26124 address on the SPARC when compiling PIC). Scratch registers need 26125 not have the same mode as the value being copied, and usually hold 26126 a different value that that being copied. Special patterns in the 26127 md file are needed to describe how the copy is performed with the 26128 help of the scratch register; these patterns also describe the 26129 number, register class(es) and mode(s) of the scratch register(s). 26130 26131 In some cases, both an intermediate and a scratch register are 26132 required. 26133 26134 For input reloads, this target hook is called with nonzero IN_P, 26135 and X is an rtx that needs to be copied to a register of class 26136 RELOAD_CLASS in RELOAD_MODE. For output reloads, this target hook 26137 is called with zero IN_P, and a register of class RELOAD_CLASS 26138 needs to be copied to rtx X in RELOAD_MODE. 26139 26140 If copying a register of RELOAD_CLASS from/to X requires an 26141 intermediate register, the hook `secondary_reload' should return 26142 the register class required for this intermediate register. If no 26143 intermediate register is required, it should return NO_REGS. If 26144 more than one intermediate register is required, describe the one 26145 that is closest in the copy chain to the reload register. 26146 26147 If scratch registers are needed, you also have to describe how to 26148 perform the copy from/to the reload register to/from this closest 26149 intermediate register. Or if no intermediate register is 26150 required, but still a scratch register is needed, describe the 26151 copy from/to the reload register to/from the reload operand X. 26152 26153 You do this by setting `sri->icode' to the instruction code of a 26154 pattern in the md file which performs the move. Operands 0 and 1 26155 are the output and input of this copy, respectively. Operands 26156 from operand 2 onward are for scratch operands. These scratch 26157 operands must have a mode, and a single-register-class output 26158 constraint. 26159 26160 When an intermediate register is used, the `secondary_reload' hook 26161 will be called again to determine how to copy the intermediate 26162 register to/from the reload operand X, so your hook must also have 26163 code to handle the register class of the intermediate operand. 26164 26165 X might be a pseudo-register or a `subreg' of a pseudo-register, 26166 which could either be in a hard register or in memory. Use 26167 `true_regnum' to find out; it will return -1 if the pseudo is in 26168 memory and the hard register number if it is in a register. 26169 26170 Scratch operands in memory (constraint `"=m"' / `"=&m"') are 26171 currently not supported. For the time being, you will have to 26172 continue to use `SECONDARY_MEMORY_NEEDED' for that purpose. 26173 26174 `copy_cost' also uses this target hook to find out how values are 26175 copied. If you want it to include some extra cost for the need to 26176 allocate (a) scratch register(s), set `sri->extra_cost' to the 26177 additional cost. Or if two dependent moves are supposed to have a 26178 lower cost than the sum of the individual moves due to expected 26179 fortuitous scheduling and/or special forwarding logic, you can set 26180 `sri->extra_cost' to a negative amount. 26181 26182 -- Macro: SECONDARY_RELOAD_CLASS (CLASS, MODE, X) 26183 -- Macro: SECONDARY_INPUT_RELOAD_CLASS (CLASS, MODE, X) 26184 -- Macro: SECONDARY_OUTPUT_RELOAD_CLASS (CLASS, MODE, X) 26185 These macros are obsolete, new ports should use the target hook 26186 `TARGET_SECONDARY_RELOAD' instead. 26187 26188 These are obsolete macros, replaced by the 26189 `TARGET_SECONDARY_RELOAD' target hook. Older ports still define 26190 these macros to indicate to the reload phase that it may need to 26191 allocate at least one register for a reload in addition to the 26192 register to contain the data. Specifically, if copying X to a 26193 register CLASS in MODE requires an intermediate register, you were 26194 supposed to define `SECONDARY_INPUT_RELOAD_CLASS' to return the 26195 largest register class all of whose registers can be used as 26196 intermediate registers or scratch registers. 26197 26198 If copying a register CLASS in MODE to X requires an intermediate 26199 or scratch register, `SECONDARY_OUTPUT_RELOAD_CLASS' was supposed 26200 to be defined be defined to return the largest register class 26201 required. If the requirements for input and output reloads were 26202 the same, the macro `SECONDARY_RELOAD_CLASS' should have been used 26203 instead of defining both macros identically. 26204 26205 The values returned by these macros are often `GENERAL_REGS'. 26206 Return `NO_REGS' if no spare register is needed; i.e., if X can be 26207 directly copied to or from a register of CLASS in MODE without 26208 requiring a scratch register. Do not define this macro if it 26209 would always return `NO_REGS'. 26210 26211 If a scratch register is required (either with or without an 26212 intermediate register), you were supposed to define patterns for 26213 `reload_inM' or `reload_outM', as required (*note Standard 26214 Names::. These patterns, which were normally implemented with a 26215 `define_expand', should be similar to the `movM' patterns, except 26216 that operand 2 is the scratch register. 26217 26218 These patterns need constraints for the reload register and scratch 26219 register that contain a single register class. If the original 26220 reload register (whose class is CLASS) can meet the constraint 26221 given in the pattern, the value returned by these macros is used 26222 for the class of the scratch register. Otherwise, two additional 26223 reload registers are required. Their classes are obtained from 26224 the constraints in the insn pattern. 26225 26226 X might be a pseudo-register or a `subreg' of a pseudo-register, 26227 which could either be in a hard register or in memory. Use 26228 `true_regnum' to find out; it will return -1 if the pseudo is in 26229 memory and the hard register number if it is in a register. 26230 26231 These macros should not be used in the case where a particular 26232 class of registers can only be copied to memory and not to another 26233 class of registers. In that case, secondary reload registers are 26234 not needed and would not be helpful. Instead, a stack location 26235 must be used to perform the copy and the `movM' pattern should use 26236 memory as an intermediate storage. This case often occurs between 26237 floating-point and general registers. 26238 26239 -- Macro: SECONDARY_MEMORY_NEEDED (CLASS1, CLASS2, M) 26240 Certain machines have the property that some registers cannot be 26241 copied to some other registers without using memory. Define this 26242 macro on those machines to be a C expression that is nonzero if 26243 objects of mode M in registers of CLASS1 can only be copied to 26244 registers of class CLASS2 by storing a register of CLASS1 into 26245 memory and loading that memory location into a register of CLASS2. 26246 26247 Do not define this macro if its value would always be zero. 26248 26249 -- Macro: SECONDARY_MEMORY_NEEDED_RTX (MODE) 26250 Normally when `SECONDARY_MEMORY_NEEDED' is defined, the compiler 26251 allocates a stack slot for a memory location needed for register 26252 copies. If this macro is defined, the compiler instead uses the 26253 memory location defined by this macro. 26254 26255 Do not define this macro if you do not define 26256 `SECONDARY_MEMORY_NEEDED'. 26257 26258 -- Macro: SECONDARY_MEMORY_NEEDED_MODE (MODE) 26259 When the compiler needs a secondary memory location to copy 26260 between two registers of mode MODE, it normally allocates 26261 sufficient memory to hold a quantity of `BITS_PER_WORD' bits and 26262 performs the store and load operations in a mode that many bits 26263 wide and whose class is the same as that of MODE. 26264 26265 This is right thing to do on most machines because it ensures that 26266 all bits of the register are copied and prevents accesses to the 26267 registers in a narrower mode, which some machines prohibit for 26268 floating-point registers. 26269 26270 However, this default behavior is not correct on some machines, 26271 such as the DEC Alpha, that store short integers in floating-point 26272 registers differently than in integer registers. On those 26273 machines, the default widening will not work correctly and you 26274 must define this macro to suppress that widening in some cases. 26275 See the file `alpha.h' for details. 26276 26277 Do not define this macro if you do not define 26278 `SECONDARY_MEMORY_NEEDED' or if widening MODE to a mode that is 26279 `BITS_PER_WORD' bits wide is correct for your machine. 26280 26281 -- Macro: SMALL_REGISTER_CLASSES 26282 On some machines, it is risky to let hard registers live across 26283 arbitrary insns. Typically, these machines have instructions that 26284 require values to be in specific registers (like an accumulator), 26285 and reload will fail if the required hard register is used for 26286 another purpose across such an insn. 26287 26288 Define `SMALL_REGISTER_CLASSES' to be an expression with a nonzero 26289 value on these machines. When this macro has a nonzero value, the 26290 compiler will try to minimize the lifetime of hard registers. 26291 26292 It is always safe to define this macro with a nonzero value, but 26293 if you unnecessarily define it, you will reduce the amount of 26294 optimizations that can be performed in some cases. If you do not 26295 define this macro with a nonzero value when it is required, the 26296 compiler will run out of spill registers and print a fatal error 26297 message. For most machines, you should not define this macro at 26298 all. 26299 26300 -- Macro: CLASS_LIKELY_SPILLED_P (CLASS) 26301 A C expression whose value is nonzero if pseudos that have been 26302 assigned to registers of class CLASS would likely be spilled 26303 because registers of CLASS are needed for spill registers. 26304 26305 The default value of this macro returns 1 if CLASS has exactly one 26306 register and zero otherwise. On most machines, this default 26307 should be used. Only define this macro to some other expression 26308 if pseudos allocated by `local-alloc.c' end up in memory because 26309 their hard registers were needed for spill registers. If this 26310 macro returns nonzero for those classes, those pseudos will only 26311 be allocated by `global.c', which knows how to reallocate the 26312 pseudo to another register. If there would not be another 26313 register available for reallocation, you should not change the 26314 definition of this macro since the only effect of such a 26315 definition would be to slow down register allocation. 26316 26317 -- Macro: CLASS_MAX_NREGS (CLASS, MODE) 26318 A C expression for the maximum number of consecutive registers of 26319 class CLASS needed to hold a value of mode MODE. 26320 26321 This is closely related to the macro `HARD_REGNO_NREGS'. In fact, 26322 the value of the macro `CLASS_MAX_NREGS (CLASS, MODE)' should be 26323 the maximum value of `HARD_REGNO_NREGS (REGNO, MODE)' for all 26324 REGNO values in the class CLASS. 26325 26326 This macro helps control the handling of multiple-word values in 26327 the reload pass. 26328 26329 -- Macro: CANNOT_CHANGE_MODE_CLASS (FROM, TO, CLASS) 26330 If defined, a C expression that returns nonzero for a CLASS for 26331 which a change from mode FROM to mode TO is invalid. 26332 26333 For the example, loading 32-bit integer or floating-point objects 26334 into floating-point registers on the Alpha extends them to 64 bits. 26335 Therefore loading a 64-bit object and then storing it as a 32-bit 26336 object does not store the low-order 32 bits, as would be the case 26337 for a normal register. Therefore, `alpha.h' defines 26338 `CANNOT_CHANGE_MODE_CLASS' as below: 26339 26340 #define CANNOT_CHANGE_MODE_CLASS(FROM, TO, CLASS) \ 26341 (GET_MODE_SIZE (FROM) != GET_MODE_SIZE (TO) \ 26342 ? reg_classes_intersect_p (FLOAT_REGS, (CLASS)) : 0) 26343 26344 -- Target Hook: const enum reg_class * TARGET_IRA_COVER_CLASSES () 26345 Return an array of cover classes for the Integrated Register 26346 Allocator (IRA). Cover classes are a set of non-intersecting 26347 register classes covering all hard registers used for register 26348 allocation purposes. If a move between two registers in the same 26349 cover class is possible, it should be cheaper than a load or store 26350 of the registers. The array is terminated by a `LIM_REG_CLASSES' 26351 element. 26352 26353 This hook is called once at compiler startup, after the 26354 command-line options have been processed. It is then re-examined 26355 by every call to `target_reinit'. 26356 26357 The default implementation returns `IRA_COVER_CLASSES', if defined, 26358 otherwise there is no default implementation. You must define 26359 either this macro or `IRA_COVER_CLASSES' in order to use the 26360 integrated register allocator with Chaitin-Briggs coloring. If the 26361 macro is not defined, the only available coloring algorithm is 26362 Chow's priority coloring. 26363 26364 -- Macro: IRA_COVER_CLASSES 26365 See the documentation for `TARGET_IRA_COVER_CLASSES'. 26366 26367 26368 File: gccint.info, Node: Old Constraints, Next: Stack and Calling, Prev: Register Classes, Up: Target Macros 26369 26370 17.9 Obsolete Macros for Defining Constraints 26371 ============================================= 26372 26373 Machine-specific constraints can be defined with these macros instead 26374 of the machine description constructs described in *Note Define 26375 Constraints::. This mechanism is obsolete. New ports should not use 26376 it; old ports should convert to the new mechanism. 26377 26378 -- Macro: CONSTRAINT_LEN (CHAR, STR) 26379 For the constraint at the start of STR, which starts with the 26380 letter C, return the length. This allows you to have register 26381 class / constant / extra constraints that are longer than a single 26382 letter; you don't need to define this macro if you can do with 26383 single-letter constraints only. The definition of this macro 26384 should use DEFAULT_CONSTRAINT_LEN for all the characters that you 26385 don't want to handle specially. There are some sanity checks in 26386 genoutput.c that check the constraint lengths for the md file, so 26387 you can also use this macro to help you while you are 26388 transitioning from a byzantine single-letter-constraint scheme: 26389 when you return a negative length for a constraint you want to 26390 re-use, genoutput will complain about every instance where it is 26391 used in the md file. 26392 26393 -- Macro: REG_CLASS_FROM_LETTER (CHAR) 26394 A C expression which defines the machine-dependent operand 26395 constraint letters for register classes. If CHAR is such a 26396 letter, the value should be the register class corresponding to 26397 it. Otherwise, the value should be `NO_REGS'. The register 26398 letter `r', corresponding to class `GENERAL_REGS', will not be 26399 passed to this macro; you do not need to handle it. 26400 26401 -- Macro: REG_CLASS_FROM_CONSTRAINT (CHAR, STR) 26402 Like `REG_CLASS_FROM_LETTER', but you also get the constraint 26403 string passed in STR, so that you can use suffixes to distinguish 26404 between different variants. 26405 26406 -- Macro: CONST_OK_FOR_LETTER_P (VALUE, C) 26407 A C expression that defines the machine-dependent operand 26408 constraint letters (`I', `J', `K', ... `P') that specify 26409 particular ranges of integer values. If C is one of those 26410 letters, the expression should check that VALUE, an integer, is in 26411 the appropriate range and return 1 if so, 0 otherwise. If C is 26412 not one of those letters, the value should be 0 regardless of 26413 VALUE. 26414 26415 -- Macro: CONST_OK_FOR_CONSTRAINT_P (VALUE, C, STR) 26416 Like `CONST_OK_FOR_LETTER_P', but you also get the constraint 26417 string passed in STR, so that you can use suffixes to distinguish 26418 between different variants. 26419 26420 -- Macro: CONST_DOUBLE_OK_FOR_LETTER_P (VALUE, C) 26421 A C expression that defines the machine-dependent operand 26422 constraint letters that specify particular ranges of 26423 `const_double' values (`G' or `H'). 26424 26425 If C is one of those letters, the expression should check that 26426 VALUE, an RTX of code `const_double', is in the appropriate range 26427 and return 1 if so, 0 otherwise. If C is not one of those 26428 letters, the value should be 0 regardless of VALUE. 26429 26430 `const_double' is used for all floating-point constants and for 26431 `DImode' fixed-point constants. A given letter can accept either 26432 or both kinds of values. It can use `GET_MODE' to distinguish 26433 between these kinds. 26434 26435 -- Macro: CONST_DOUBLE_OK_FOR_CONSTRAINT_P (VALUE, C, STR) 26436 Like `CONST_DOUBLE_OK_FOR_LETTER_P', but you also get the 26437 constraint string passed in STR, so that you can use suffixes to 26438 distinguish between different variants. 26439 26440 -- Macro: EXTRA_CONSTRAINT (VALUE, C) 26441 A C expression that defines the optional machine-dependent 26442 constraint letters that can be used to segregate specific types of 26443 operands, usually memory references, for the target machine. Any 26444 letter that is not elsewhere defined and not matched by 26445 `REG_CLASS_FROM_LETTER' / `REG_CLASS_FROM_CONSTRAINT' may be used. 26446 Normally this macro will not be defined. 26447 26448 If it is required for a particular target machine, it should 26449 return 1 if VALUE corresponds to the operand type represented by 26450 the constraint letter C. If C is not defined as an extra 26451 constraint, the value returned should be 0 regardless of VALUE. 26452 26453 For example, on the ROMP, load instructions cannot have their 26454 output in r0 if the memory reference contains a symbolic address. 26455 Constraint letter `Q' is defined as representing a memory address 26456 that does _not_ contain a symbolic address. An alternative is 26457 specified with a `Q' constraint on the input and `r' on the 26458 output. The next alternative specifies `m' on the input and a 26459 register class that does not include r0 on the output. 26460 26461 -- Macro: EXTRA_CONSTRAINT_STR (VALUE, C, STR) 26462 Like `EXTRA_CONSTRAINT', but you also get the constraint string 26463 passed in STR, so that you can use suffixes to distinguish between 26464 different variants. 26465 26466 -- Macro: EXTRA_MEMORY_CONSTRAINT (C, STR) 26467 A C expression that defines the optional machine-dependent 26468 constraint letters, amongst those accepted by `EXTRA_CONSTRAINT', 26469 that should be treated like memory constraints by the reload pass. 26470 26471 It should return 1 if the operand type represented by the 26472 constraint at the start of STR, the first letter of which is the 26473 letter C, comprises a subset of all memory references including 26474 all those whose address is simply a base register. This allows 26475 the reload pass to reload an operand, if it does not directly 26476 correspond to the operand type of C, by copying its address into a 26477 base register. 26478 26479 For example, on the S/390, some instructions do not accept 26480 arbitrary memory references, but only those that do not make use 26481 of an index register. The constraint letter `Q' is defined via 26482 `EXTRA_CONSTRAINT' as representing a memory address of this type. 26483 If the letter `Q' is marked as `EXTRA_MEMORY_CONSTRAINT', a `Q' 26484 constraint can handle any memory operand, because the reload pass 26485 knows it can be reloaded by copying the memory address into a base 26486 register if required. This is analogous to the way a `o' 26487 constraint can handle any memory operand. 26488 26489 -- Macro: EXTRA_ADDRESS_CONSTRAINT (C, STR) 26490 A C expression that defines the optional machine-dependent 26491 constraint letters, amongst those accepted by `EXTRA_CONSTRAINT' / 26492 `EXTRA_CONSTRAINT_STR', that should be treated like address 26493 constraints by the reload pass. 26494 26495 It should return 1 if the operand type represented by the 26496 constraint at the start of STR, which starts with the letter C, 26497 comprises a subset of all memory addresses including all those 26498 that consist of just a base register. This allows the reload pass 26499 to reload an operand, if it does not directly correspond to the 26500 operand type of STR, by copying it into a base register. 26501 26502 Any constraint marked as `EXTRA_ADDRESS_CONSTRAINT' can only be 26503 used with the `address_operand' predicate. It is treated 26504 analogously to the `p' constraint. 26505 26506 26507 File: gccint.info, Node: Stack and Calling, Next: Varargs, Prev: Old Constraints, Up: Target Macros 26508 26509 17.10 Stack Layout and Calling Conventions 26510 ========================================== 26511 26512 This describes the stack layout and calling conventions. 26513 26514 * Menu: 26515 26516 * Frame Layout:: 26517 * Exception Handling:: 26518 * Stack Checking:: 26519 * Frame Registers:: 26520 * Elimination:: 26521 * Stack Arguments:: 26522 * Register Arguments:: 26523 * Scalar Return:: 26524 * Aggregate Return:: 26525 * Caller Saves:: 26526 * Function Entry:: 26527 * Profiling:: 26528 * Tail Calls:: 26529 * Stack Smashing Protection:: 26530 26531 26532 File: gccint.info, Node: Frame Layout, Next: Exception Handling, Up: Stack and Calling 26533 26534 17.10.1 Basic Stack Layout 26535 -------------------------- 26536 26537 Here is the basic stack layout. 26538 26539 -- Macro: STACK_GROWS_DOWNWARD 26540 Define this macro if pushing a word onto the stack moves the stack 26541 pointer to a smaller address. 26542 26543 When we say, "define this macro if ...", it means that the 26544 compiler checks this macro only with `#ifdef' so the precise 26545 definition used does not matter. 26546 26547 -- Macro: STACK_PUSH_CODE 26548 This macro defines the operation used when something is pushed on 26549 the stack. In RTL, a push operation will be `(set (mem 26550 (STACK_PUSH_CODE (reg sp))) ...)' 26551 26552 The choices are `PRE_DEC', `POST_DEC', `PRE_INC', and `POST_INC'. 26553 Which of these is correct depends on the stack direction and on 26554 whether the stack pointer points to the last item on the stack or 26555 whether it points to the space for the next item on the stack. 26556 26557 The default is `PRE_DEC' when `STACK_GROWS_DOWNWARD' is defined, 26558 which is almost always right, and `PRE_INC' otherwise, which is 26559 often wrong. 26560 26561 -- Macro: FRAME_GROWS_DOWNWARD 26562 Define this macro to nonzero value if the addresses of local 26563 variable slots are at negative offsets from the frame pointer. 26564 26565 -- Macro: ARGS_GROW_DOWNWARD 26566 Define this macro if successive arguments to a function occupy 26567 decreasing addresses on the stack. 26568 26569 -- Macro: STARTING_FRAME_OFFSET 26570 Offset from the frame pointer to the first local variable slot to 26571 be allocated. 26572 26573 If `FRAME_GROWS_DOWNWARD', find the next slot's offset by 26574 subtracting the first slot's length from `STARTING_FRAME_OFFSET'. 26575 Otherwise, it is found by adding the length of the first slot to 26576 the value `STARTING_FRAME_OFFSET'. 26577 26578 -- Macro: STACK_ALIGNMENT_NEEDED 26579 Define to zero to disable final alignment of the stack during 26580 reload. The nonzero default for this macro is suitable for most 26581 ports. 26582 26583 On ports where `STARTING_FRAME_OFFSET' is nonzero or where there 26584 is a register save block following the local block that doesn't 26585 require alignment to `STACK_BOUNDARY', it may be beneficial to 26586 disable stack alignment and do it in the backend. 26587 26588 -- Macro: STACK_POINTER_OFFSET 26589 Offset from the stack pointer register to the first location at 26590 which outgoing arguments are placed. If not specified, the 26591 default value of zero is used. This is the proper value for most 26592 machines. 26593 26594 If `ARGS_GROW_DOWNWARD', this is the offset to the location above 26595 the first location at which outgoing arguments are placed. 26596 26597 -- Macro: FIRST_PARM_OFFSET (FUNDECL) 26598 Offset from the argument pointer register to the first argument's 26599 address. On some machines it may depend on the data type of the 26600 function. 26601 26602 If `ARGS_GROW_DOWNWARD', this is the offset to the location above 26603 the first argument's address. 26604 26605 -- Macro: STACK_DYNAMIC_OFFSET (FUNDECL) 26606 Offset from the stack pointer register to an item dynamically 26607 allocated on the stack, e.g., by `alloca'. 26608 26609 The default value for this macro is `STACK_POINTER_OFFSET' plus the 26610 length of the outgoing arguments. The default is correct for most 26611 machines. See `function.c' for details. 26612 26613 -- Macro: INITIAL_FRAME_ADDRESS_RTX 26614 A C expression whose value is RTL representing the address of the 26615 initial stack frame. This address is passed to `RETURN_ADDR_RTX' 26616 and `DYNAMIC_CHAIN_ADDRESS'. If you don't define this macro, a 26617 reasonable default value will be used. Define this macro in order 26618 to make frame pointer elimination work in the presence of 26619 `__builtin_frame_address (count)' and `__builtin_return_address 26620 (count)' for `count' not equal to zero. 26621 26622 -- Macro: DYNAMIC_CHAIN_ADDRESS (FRAMEADDR) 26623 A C expression whose value is RTL representing the address in a 26624 stack frame where the pointer to the caller's frame is stored. 26625 Assume that FRAMEADDR is an RTL expression for the address of the 26626 stack frame itself. 26627 26628 If you don't define this macro, the default is to return the value 26629 of FRAMEADDR--that is, the stack frame address is also the address 26630 of the stack word that points to the previous frame. 26631 26632 -- Macro: SETUP_FRAME_ADDRESSES 26633 If defined, a C expression that produces the machine-specific code 26634 to setup the stack so that arbitrary frames can be accessed. For 26635 example, on the SPARC, we must flush all of the register windows 26636 to the stack before we can access arbitrary stack frames. You 26637 will seldom need to define this macro. 26638 26639 -- Target Hook: bool TARGET_BUILTIN_SETJMP_FRAME_VALUE () 26640 This target hook should return an rtx that is used to store the 26641 address of the current frame into the built in `setjmp' buffer. 26642 The default value, `virtual_stack_vars_rtx', is correct for most 26643 machines. One reason you may need to define this target hook is if 26644 `hard_frame_pointer_rtx' is the appropriate value on your machine. 26645 26646 -- Macro: FRAME_ADDR_RTX (FRAMEADDR) 26647 A C expression whose value is RTL representing the value of the 26648 frame address for the current frame. FRAMEADDR is the frame 26649 pointer of the current frame. This is used for 26650 __builtin_frame_address. You need only define this macro if the 26651 frame address is not the same as the frame pointer. Most machines 26652 do not need to define it. 26653 26654 -- Macro: RETURN_ADDR_RTX (COUNT, FRAMEADDR) 26655 A C expression whose value is RTL representing the value of the 26656 return address for the frame COUNT steps up from the current 26657 frame, after the prologue. FRAMEADDR is the frame pointer of the 26658 COUNT frame, or the frame pointer of the COUNT - 1 frame if 26659 `RETURN_ADDR_IN_PREVIOUS_FRAME' is defined. 26660 26661 The value of the expression must always be the correct address when 26662 COUNT is zero, but may be `NULL_RTX' if there is no way to 26663 determine the return address of other frames. 26664 26665 -- Macro: RETURN_ADDR_IN_PREVIOUS_FRAME 26666 Define this if the return address of a particular stack frame is 26667 accessed from the frame pointer of the previous stack frame. 26668 26669 -- Macro: INCOMING_RETURN_ADDR_RTX 26670 A C expression whose value is RTL representing the location of the 26671 incoming return address at the beginning of any function, before 26672 the prologue. This RTL is either a `REG', indicating that the 26673 return value is saved in `REG', or a `MEM' representing a location 26674 in the stack. 26675 26676 You only need to define this macro if you want to support call 26677 frame debugging information like that provided by DWARF 2. 26678 26679 If this RTL is a `REG', you should also define 26680 `DWARF_FRAME_RETURN_COLUMN' to `DWARF_FRAME_REGNUM (REGNO)'. 26681 26682 -- Macro: DWARF_ALT_FRAME_RETURN_COLUMN 26683 A C expression whose value is an integer giving a DWARF 2 column 26684 number that may be used as an alternative return column. The 26685 column must not correspond to any gcc hard register (that is, it 26686 must not be in the range of `DWARF_FRAME_REGNUM'). 26687 26688 This macro can be useful if `DWARF_FRAME_RETURN_COLUMN' is set to a 26689 general register, but an alternative column needs to be used for 26690 signal frames. Some targets have also used different frame return 26691 columns over time. 26692 26693 -- Macro: DWARF_ZERO_REG 26694 A C expression whose value is an integer giving a DWARF 2 register 26695 number that is considered to always have the value zero. This 26696 should only be defined if the target has an architected zero 26697 register, and someone decided it was a good idea to use that 26698 register number to terminate the stack backtrace. New ports 26699 should avoid this. 26700 26701 -- Target Hook: void TARGET_DWARF_HANDLE_FRAME_UNSPEC (const char 26702 *LABEL, rtx PATTERN, int INDEX) 26703 This target hook allows the backend to emit frame-related insns 26704 that contain UNSPECs or UNSPEC_VOLATILEs. The DWARF 2 call frame 26705 debugging info engine will invoke it on insns of the form 26706 (set (reg) (unspec [...] UNSPEC_INDEX)) 26707 and 26708 (set (reg) (unspec_volatile [...] UNSPECV_INDEX)). 26709 to let the backend emit the call frame instructions. LABEL is the 26710 CFI label attached to the insn, PATTERN is the pattern of the insn 26711 and INDEX is `UNSPEC_INDEX' or `UNSPECV_INDEX'. 26712 26713 -- Macro: INCOMING_FRAME_SP_OFFSET 26714 A C expression whose value is an integer giving the offset, in 26715 bytes, from the value of the stack pointer register to the top of 26716 the stack frame at the beginning of any function, before the 26717 prologue. The top of the frame is defined to be the value of the 26718 stack pointer in the previous frame, just before the call 26719 instruction. 26720 26721 You only need to define this macro if you want to support call 26722 frame debugging information like that provided by DWARF 2. 26723 26724 -- Macro: ARG_POINTER_CFA_OFFSET (FUNDECL) 26725 A C expression whose value is an integer giving the offset, in 26726 bytes, from the argument pointer to the canonical frame address 26727 (cfa). The final value should coincide with that calculated by 26728 `INCOMING_FRAME_SP_OFFSET'. Which is unfortunately not usable 26729 during virtual register instantiation. 26730 26731 The default value for this macro is `FIRST_PARM_OFFSET (fundecl)', 26732 which is correct for most machines; in general, the arguments are 26733 found immediately before the stack frame. Note that this is not 26734 the case on some targets that save registers into the caller's 26735 frame, such as SPARC and rs6000, and so such targets need to 26736 define this macro. 26737 26738 You only need to define this macro if the default is incorrect, 26739 and you want to support call frame debugging information like that 26740 provided by DWARF 2. 26741 26742 -- Macro: FRAME_POINTER_CFA_OFFSET (FUNDECL) 26743 If defined, a C expression whose value is an integer giving the 26744 offset in bytes from the frame pointer to the canonical frame 26745 address (cfa). The final value should coincide with that 26746 calculated by `INCOMING_FRAME_SP_OFFSET'. 26747 26748 Normally the CFA is calculated as an offset from the argument 26749 pointer, via `ARG_POINTER_CFA_OFFSET', but if the argument pointer 26750 is variable due to the ABI, this may not be possible. If this 26751 macro is defined, it implies that the virtual register 26752 instantiation should be based on the frame pointer instead of the 26753 argument pointer. Only one of `FRAME_POINTER_CFA_OFFSET' and 26754 `ARG_POINTER_CFA_OFFSET' should be defined. 26755 26756 -- Macro: CFA_FRAME_BASE_OFFSET (FUNDECL) 26757 If defined, a C expression whose value is an integer giving the 26758 offset in bytes from the canonical frame address (cfa) to the 26759 frame base used in DWARF 2 debug information. The default is 26760 zero. A different value may reduce the size of debug information 26761 on some ports. 26762 26763 26764 File: gccint.info, Node: Exception Handling, Next: Stack Checking, Prev: Frame Layout, Up: Stack and Calling 26765 26766 17.10.2 Exception Handling Support 26767 ---------------------------------- 26768 26769 -- Macro: EH_RETURN_DATA_REGNO (N) 26770 A C expression whose value is the Nth register number used for 26771 data by exception handlers, or `INVALID_REGNUM' if fewer than N 26772 registers are usable. 26773 26774 The exception handling library routines communicate with the 26775 exception handlers via a set of agreed upon registers. Ideally 26776 these registers should be call-clobbered; it is possible to use 26777 call-saved registers, but may negatively impact code size. The 26778 target must support at least 2 data registers, but should define 4 26779 if there are enough free registers. 26780 26781 You must define this macro if you want to support call frame 26782 exception handling like that provided by DWARF 2. 26783 26784 -- Macro: EH_RETURN_STACKADJ_RTX 26785 A C expression whose value is RTL representing a location in which 26786 to store a stack adjustment to be applied before function return. 26787 This is used to unwind the stack to an exception handler's call 26788 frame. It will be assigned zero on code paths that return 26789 normally. 26790 26791 Typically this is a call-clobbered hard register that is otherwise 26792 untouched by the epilogue, but could also be a stack slot. 26793 26794 Do not define this macro if the stack pointer is saved and restored 26795 by the regular prolog and epilog code in the call frame itself; in 26796 this case, the exception handling library routines will update the 26797 stack location to be restored in place. Otherwise, you must define 26798 this macro if you want to support call frame exception handling 26799 like that provided by DWARF 2. 26800 26801 -- Macro: EH_RETURN_HANDLER_RTX 26802 A C expression whose value is RTL representing a location in which 26803 to store the address of an exception handler to which we should 26804 return. It will not be assigned on code paths that return 26805 normally. 26806 26807 Typically this is the location in the call frame at which the 26808 normal return address is stored. For targets that return by 26809 popping an address off the stack, this might be a memory address 26810 just below the _target_ call frame rather than inside the current 26811 call frame. If defined, `EH_RETURN_STACKADJ_RTX' will have already 26812 been assigned, so it may be used to calculate the location of the 26813 target call frame. 26814 26815 Some targets have more complex requirements than storing to an 26816 address calculable during initial code generation. In that case 26817 the `eh_return' instruction pattern should be used instead. 26818 26819 If you want to support call frame exception handling, you must 26820 define either this macro or the `eh_return' instruction pattern. 26821 26822 -- Macro: RETURN_ADDR_OFFSET 26823 If defined, an integer-valued C expression for which rtl will be 26824 generated to add it to the exception handler address before it is 26825 searched in the exception handling tables, and to subtract it 26826 again from the address before using it to return to the exception 26827 handler. 26828 26829 -- Macro: ASM_PREFERRED_EH_DATA_FORMAT (CODE, GLOBAL) 26830 This macro chooses the encoding of pointers embedded in the 26831 exception handling sections. If at all possible, this should be 26832 defined such that the exception handling section will not require 26833 dynamic relocations, and so may be read-only. 26834 26835 CODE is 0 for data, 1 for code labels, 2 for function pointers. 26836 GLOBAL is true if the symbol may be affected by dynamic 26837 relocations. The macro should return a combination of the 26838 `DW_EH_PE_*' defines as found in `dwarf2.h'. 26839 26840 If this macro is not defined, pointers will not be encoded but 26841 represented directly. 26842 26843 -- Macro: ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX (FILE, ENCODING, SIZE, 26844 ADDR, DONE) 26845 This macro allows the target to emit whatever special magic is 26846 required to represent the encoding chosen by 26847 `ASM_PREFERRED_EH_DATA_FORMAT'. Generic code takes care of 26848 pc-relative and indirect encodings; this must be defined if the 26849 target uses text-relative or data-relative encodings. 26850 26851 This is a C statement that branches to DONE if the format was 26852 handled. ENCODING is the format chosen, SIZE is the number of 26853 bytes that the format occupies, ADDR is the `SYMBOL_REF' to be 26854 emitted. 26855 26856 -- Macro: MD_UNWIND_SUPPORT 26857 A string specifying a file to be #include'd in unwind-dw2.c. The 26858 file so included typically defines `MD_FALLBACK_FRAME_STATE_FOR'. 26859 26860 -- Macro: MD_FALLBACK_FRAME_STATE_FOR (CONTEXT, FS) 26861 This macro allows the target to add CPU and operating system 26862 specific code to the call-frame unwinder for use when there is no 26863 unwind data available. The most common reason to implement this 26864 macro is to unwind through signal frames. 26865 26866 This macro is called from `uw_frame_state_for' in `unwind-dw2.c', 26867 `unwind-dw2-xtensa.c' and `unwind-ia64.c'. CONTEXT is an 26868 `_Unwind_Context'; FS is an `_Unwind_FrameState'. Examine 26869 `context->ra' for the address of the code being executed and 26870 `context->cfa' for the stack pointer value. If the frame can be 26871 decoded, the register save addresses should be updated in FS and 26872 the macro should evaluate to `_URC_NO_REASON'. If the frame 26873 cannot be decoded, the macro should evaluate to 26874 `_URC_END_OF_STACK'. 26875 26876 For proper signal handling in Java this macro is accompanied by 26877 `MAKE_THROW_FRAME', defined in `libjava/include/*-signal.h' 26878 headers. 26879 26880 -- Macro: MD_HANDLE_UNWABI (CONTEXT, FS) 26881 This macro allows the target to add operating system specific code 26882 to the call-frame unwinder to handle the IA-64 `.unwabi' unwinding 26883 directive, usually used for signal or interrupt frames. 26884 26885 This macro is called from `uw_update_context' in `unwind-ia64.c'. 26886 CONTEXT is an `_Unwind_Context'; FS is an `_Unwind_FrameState'. 26887 Examine `fs->unwabi' for the abi and context in the `.unwabi' 26888 directive. If the `.unwabi' directive can be handled, the 26889 register save addresses should be updated in FS. 26890 26891 -- Macro: TARGET_USES_WEAK_UNWIND_INFO 26892 A C expression that evaluates to true if the target requires unwind 26893 info to be given comdat linkage. Define it to be `1' if comdat 26894 linkage is necessary. The default is `0'. 26895 26896 26897 File: gccint.info, Node: Stack Checking, Next: Frame Registers, Prev: Exception Handling, Up: Stack and Calling 26898 26899 17.10.3 Specifying How Stack Checking is Done 26900 --------------------------------------------- 26901 26902 GCC will check that stack references are within the boundaries of the 26903 stack, if the option `-fstack-check' is specified, in one of three ways: 26904 26905 1. If the value of the `STACK_CHECK_BUILTIN' macro is nonzero, GCC 26906 will assume that you have arranged for full stack checking to be 26907 done at appropriate places in the configuration files. GCC will 26908 not do other special processing. 26909 26910 2. If `STACK_CHECK_BUILTIN' is zero and the value of the 26911 `STACK_CHECK_STATIC_BUILTIN' macro is nonzero, GCC will assume 26912 that you have arranged for static stack checking (checking of the 26913 static stack frame of functions) to be done at appropriate places 26914 in the configuration files. GCC will only emit code to do dynamic 26915 stack checking (checking on dynamic stack allocations) using the 26916 third approach below. 26917 26918 3. If neither of the above are true, GCC will generate code to 26919 periodically "probe" the stack pointer using the values of the 26920 macros defined below. 26921 26922 If neither STACK_CHECK_BUILTIN nor STACK_CHECK_STATIC_BUILTIN is 26923 defined, GCC will change its allocation strategy for large objects if 26924 the option `-fstack-check' is specified: they will always be allocated 26925 dynamically if their size exceeds `STACK_CHECK_MAX_VAR_SIZE' bytes. 26926 26927 -- Macro: STACK_CHECK_BUILTIN 26928 A nonzero value if stack checking is done by the configuration 26929 files in a machine-dependent manner. You should define this macro 26930 if stack checking is require by the ABI of your machine or if you 26931 would like to do stack checking in some more efficient way than 26932 the generic approach. The default value of this macro is zero. 26933 26934 -- Macro: STACK_CHECK_STATIC_BUILTIN 26935 A nonzero value if static stack checking is done by the 26936 configuration files in a machine-dependent manner. You should 26937 define this macro if you would like to do static stack checking in 26938 some more efficient way than the generic approach. The default 26939 value of this macro is zero. 26940 26941 -- Macro: STACK_CHECK_PROBE_INTERVAL 26942 An integer representing the interval at which GCC must generate 26943 stack probe instructions. You will normally define this macro to 26944 be no larger than the size of the "guard pages" at the end of a 26945 stack area. The default value of 4096 is suitable for most 26946 systems. 26947 26948 -- Macro: STACK_CHECK_PROBE_LOAD 26949 An integer which is nonzero if GCC should perform the stack probe 26950 as a load instruction and zero if GCC should use a store 26951 instruction. The default is zero, which is the most efficient 26952 choice on most systems. 26953 26954 -- Macro: STACK_CHECK_PROTECT 26955 The number of bytes of stack needed to recover from a stack 26956 overflow, for languages where such a recovery is supported. The 26957 default value of 75 words should be adequate for most machines. 26958 26959 The following macros are relevant only if neither STACK_CHECK_BUILTIN 26960 nor STACK_CHECK_STATIC_BUILTIN is defined; you can omit them altogether 26961 in the opposite case. 26962 26963 -- Macro: STACK_CHECK_MAX_FRAME_SIZE 26964 The maximum size of a stack frame, in bytes. GCC will generate 26965 probe instructions in non-leaf functions to ensure at least this 26966 many bytes of stack are available. If a stack frame is larger 26967 than this size, stack checking will not be reliable and GCC will 26968 issue a warning. The default is chosen so that GCC only generates 26969 one instruction on most systems. You should normally not change 26970 the default value of this macro. 26971 26972 -- Macro: STACK_CHECK_FIXED_FRAME_SIZE 26973 GCC uses this value to generate the above warning message. It 26974 represents the amount of fixed frame used by a function, not 26975 including space for any callee-saved registers, temporaries and 26976 user variables. You need only specify an upper bound for this 26977 amount and will normally use the default of four words. 26978 26979 -- Macro: STACK_CHECK_MAX_VAR_SIZE 26980 The maximum size, in bytes, of an object that GCC will place in the 26981 fixed area of the stack frame when the user specifies 26982 `-fstack-check'. GCC computed the default from the values of the 26983 above macros and you will normally not need to override that 26984 default. 26985 26986 26987 File: gccint.info, Node: Frame Registers, Next: Elimination, Prev: Stack Checking, Up: Stack and Calling 26988 26989 17.10.4 Registers That Address the Stack Frame 26990 ---------------------------------------------- 26991 26992 This discusses registers that address the stack frame. 26993 26994 -- Macro: STACK_POINTER_REGNUM 26995 The register number of the stack pointer register, which must also 26996 be a fixed register according to `FIXED_REGISTERS'. On most 26997 machines, the hardware determines which register this is. 26998 26999 -- Macro: FRAME_POINTER_REGNUM 27000 The register number of the frame pointer register, which is used to 27001 access automatic variables in the stack frame. On some machines, 27002 the hardware determines which register this is. On other 27003 machines, you can choose any register you wish for this purpose. 27004 27005 -- Macro: HARD_FRAME_POINTER_REGNUM 27006 On some machines the offset between the frame pointer and starting 27007 offset of the automatic variables is not known until after register 27008 allocation has been done (for example, because the saved registers 27009 are between these two locations). On those machines, define 27010 `FRAME_POINTER_REGNUM' the number of a special, fixed register to 27011 be used internally until the offset is known, and define 27012 `HARD_FRAME_POINTER_REGNUM' to be the actual hard register number 27013 used for the frame pointer. 27014 27015 You should define this macro only in the very rare circumstances 27016 when it is not possible to calculate the offset between the frame 27017 pointer and the automatic variables until after register 27018 allocation has been completed. When this macro is defined, you 27019 must also indicate in your definition of `ELIMINABLE_REGS' how to 27020 eliminate `FRAME_POINTER_REGNUM' into either 27021 `HARD_FRAME_POINTER_REGNUM' or `STACK_POINTER_REGNUM'. 27022 27023 Do not define this macro if it would be the same as 27024 `FRAME_POINTER_REGNUM'. 27025 27026 -- Macro: ARG_POINTER_REGNUM 27027 The register number of the arg pointer register, which is used to 27028 access the function's argument list. On some machines, this is 27029 the same as the frame pointer register. On some machines, the 27030 hardware determines which register this is. On other machines, 27031 you can choose any register you wish for this purpose. If this is 27032 not the same register as the frame pointer register, then you must 27033 mark it as a fixed register according to `FIXED_REGISTERS', or 27034 arrange to be able to eliminate it (*note Elimination::). 27035 27036 -- Macro: RETURN_ADDRESS_POINTER_REGNUM 27037 The register number of the return address pointer register, which 27038 is used to access the current function's return address from the 27039 stack. On some machines, the return address is not at a fixed 27040 offset from the frame pointer or stack pointer or argument 27041 pointer. This register can be defined to point to the return 27042 address on the stack, and then be converted by `ELIMINABLE_REGS' 27043 into either the frame pointer or stack pointer. 27044 27045 Do not define this macro unless there is no other way to get the 27046 return address from the stack. 27047 27048 -- Macro: STATIC_CHAIN_REGNUM 27049 -- Macro: STATIC_CHAIN_INCOMING_REGNUM 27050 Register numbers used for passing a function's static chain 27051 pointer. If register windows are used, the register number as 27052 seen by the called function is `STATIC_CHAIN_INCOMING_REGNUM', 27053 while the register number as seen by the calling function is 27054 `STATIC_CHAIN_REGNUM'. If these registers are the same, 27055 `STATIC_CHAIN_INCOMING_REGNUM' need not be defined. 27056 27057 The static chain register need not be a fixed register. 27058 27059 If the static chain is passed in memory, these macros should not be 27060 defined; instead, the next two macros should be defined. 27061 27062 -- Macro: STATIC_CHAIN 27063 -- Macro: STATIC_CHAIN_INCOMING 27064 If the static chain is passed in memory, these macros provide rtx 27065 giving `mem' expressions that denote where they are stored. 27066 `STATIC_CHAIN' and `STATIC_CHAIN_INCOMING' give the locations as 27067 seen by the calling and called functions, respectively. Often the 27068 former will be at an offset from the stack pointer and the latter 27069 at an offset from the frame pointer. 27070 27071 The variables `stack_pointer_rtx', `frame_pointer_rtx', and 27072 `arg_pointer_rtx' will have been initialized prior to the use of 27073 these macros and should be used to refer to those items. 27074 27075 If the static chain is passed in a register, the two previous 27076 macros should be defined instead. 27077 27078 -- Macro: DWARF_FRAME_REGISTERS 27079 This macro specifies the maximum number of hard registers that can 27080 be saved in a call frame. This is used to size data structures 27081 used in DWARF2 exception handling. 27082 27083 Prior to GCC 3.0, this macro was needed in order to establish a 27084 stable exception handling ABI in the face of adding new hard 27085 registers for ISA extensions. In GCC 3.0 and later, the EH ABI is 27086 insulated from changes in the number of hard registers. 27087 Nevertheless, this macro can still be used to reduce the runtime 27088 memory requirements of the exception handling routines, which can 27089 be substantial if the ISA contains a lot of registers that are not 27090 call-saved. 27091 27092 If this macro is not defined, it defaults to 27093 `FIRST_PSEUDO_REGISTER'. 27094 27095 -- Macro: PRE_GCC3_DWARF_FRAME_REGISTERS 27096 This macro is similar to `DWARF_FRAME_REGISTERS', but is provided 27097 for backward compatibility in pre GCC 3.0 compiled code. 27098 27099 If this macro is not defined, it defaults to 27100 `DWARF_FRAME_REGISTERS'. 27101 27102 -- Macro: DWARF_REG_TO_UNWIND_COLUMN (REGNO) 27103 Define this macro if the target's representation for dwarf 27104 registers is different than the internal representation for unwind 27105 column. Given a dwarf register, this macro should return the 27106 internal unwind column number to use instead. 27107 27108 See the PowerPC's SPE target for an example. 27109 27110 -- Macro: DWARF_FRAME_REGNUM (REGNO) 27111 Define this macro if the target's representation for dwarf 27112 registers used in .eh_frame or .debug_frame is different from that 27113 used in other debug info sections. Given a GCC hard register 27114 number, this macro should return the .eh_frame register number. 27115 The default is `DBX_REGISTER_NUMBER (REGNO)'. 27116 27117 27118 -- Macro: DWARF2_FRAME_REG_OUT (REGNO, FOR_EH) 27119 Define this macro to map register numbers held in the call frame 27120 info that GCC has collected using `DWARF_FRAME_REGNUM' to those 27121 that should be output in .debug_frame (`FOR_EH' is zero) and 27122 .eh_frame (`FOR_EH' is nonzero). The default is to return `REGNO'. 27123 27124 27125 27126 File: gccint.info, Node: Elimination, Next: Stack Arguments, Prev: Frame Registers, Up: Stack and Calling 27127 27128 17.10.5 Eliminating Frame Pointer and Arg Pointer 27129 ------------------------------------------------- 27130 27131 This is about eliminating the frame pointer and arg pointer. 27132 27133 -- Macro: FRAME_POINTER_REQUIRED 27134 A C expression which is nonzero if a function must have and use a 27135 frame pointer. This expression is evaluated in the reload pass. 27136 If its value is nonzero the function will have a frame pointer. 27137 27138 The expression can in principle examine the current function and 27139 decide according to the facts, but on most machines the constant 0 27140 or the constant 1 suffices. Use 0 when the machine allows code to 27141 be generated with no frame pointer, and doing so saves some time 27142 or space. Use 1 when there is no possible advantage to avoiding a 27143 frame pointer. 27144 27145 In certain cases, the compiler does not know how to produce valid 27146 code without a frame pointer. The compiler recognizes those cases 27147 and automatically gives the function a frame pointer regardless of 27148 what `FRAME_POINTER_REQUIRED' says. You don't need to worry about 27149 them. 27150 27151 In a function that does not require a frame pointer, the frame 27152 pointer register can be allocated for ordinary usage, unless you 27153 mark it as a fixed register. See `FIXED_REGISTERS' for more 27154 information. 27155 27156 -- Macro: INITIAL_FRAME_POINTER_OFFSET (DEPTH-VAR) 27157 A C statement to store in the variable DEPTH-VAR the difference 27158 between the frame pointer and the stack pointer values immediately 27159 after the function prologue. The value would be computed from 27160 information such as the result of `get_frame_size ()' and the 27161 tables of registers `regs_ever_live' and `call_used_regs'. 27162 27163 If `ELIMINABLE_REGS' is defined, this macro will be not be used and 27164 need not be defined. Otherwise, it must be defined even if 27165 `FRAME_POINTER_REQUIRED' is defined to always be true; in that 27166 case, you may set DEPTH-VAR to anything. 27167 27168 -- Macro: ELIMINABLE_REGS 27169 If defined, this macro specifies a table of register pairs used to 27170 eliminate unneeded registers that point into the stack frame. If 27171 it is not defined, the only elimination attempted by the compiler 27172 is to replace references to the frame pointer with references to 27173 the stack pointer. 27174 27175 The definition of this macro is a list of structure 27176 initializations, each of which specifies an original and 27177 replacement register. 27178 27179 On some machines, the position of the argument pointer is not 27180 known until the compilation is completed. In such a case, a 27181 separate hard register must be used for the argument pointer. 27182 This register can be eliminated by replacing it with either the 27183 frame pointer or the argument pointer, depending on whether or not 27184 the frame pointer has been eliminated. 27185 27186 In this case, you might specify: 27187 #define ELIMINABLE_REGS \ 27188 {{ARG_POINTER_REGNUM, STACK_POINTER_REGNUM}, \ 27189 {ARG_POINTER_REGNUM, FRAME_POINTER_REGNUM}, \ 27190 {FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM}} 27191 27192 Note that the elimination of the argument pointer with the stack 27193 pointer is specified first since that is the preferred elimination. 27194 27195 -- Macro: CAN_ELIMINATE (FROM-REG, TO-REG) 27196 A C expression that returns nonzero if the compiler is allowed to 27197 try to replace register number FROM-REG with register number 27198 TO-REG. This macro need only be defined if `ELIMINABLE_REGS' is 27199 defined, and will usually be the constant 1, since most of the 27200 cases preventing register elimination are things that the compiler 27201 already knows about. 27202 27203 -- Macro: INITIAL_ELIMINATION_OFFSET (FROM-REG, TO-REG, OFFSET-VAR) 27204 This macro is similar to `INITIAL_FRAME_POINTER_OFFSET'. It 27205 specifies the initial difference between the specified pair of 27206 registers. This macro must be defined if `ELIMINABLE_REGS' is 27207 defined. 27208 27209 27210 File: gccint.info, Node: Stack Arguments, Next: Register Arguments, Prev: Elimination, Up: Stack and Calling 27211 27212 17.10.6 Passing Function Arguments on the Stack 27213 ----------------------------------------------- 27214 27215 The macros in this section control how arguments are passed on the 27216 stack. See the following section for other macros that control passing 27217 certain arguments in registers. 27218 27219 -- Target Hook: bool TARGET_PROMOTE_PROTOTYPES (tree FNTYPE) 27220 This target hook returns `true' if an argument declared in a 27221 prototype as an integral type smaller than `int' should actually be 27222 passed as an `int'. In addition to avoiding errors in certain 27223 cases of mismatch, it also makes for better code on certain 27224 machines. The default is to not promote prototypes. 27225 27226 -- Macro: PUSH_ARGS 27227 A C expression. If nonzero, push insns will be used to pass 27228 outgoing arguments. If the target machine does not have a push 27229 instruction, set it to zero. That directs GCC to use an alternate 27230 strategy: to allocate the entire argument block and then store the 27231 arguments into it. When `PUSH_ARGS' is nonzero, `PUSH_ROUNDING' 27232 must be defined too. 27233 27234 -- Macro: PUSH_ARGS_REVERSED 27235 A C expression. If nonzero, function arguments will be evaluated 27236 from last to first, rather than from first to last. If this macro 27237 is not defined, it defaults to `PUSH_ARGS' on targets where the 27238 stack and args grow in opposite directions, and 0 otherwise. 27239 27240 -- Macro: PUSH_ROUNDING (NPUSHED) 27241 A C expression that is the number of bytes actually pushed onto the 27242 stack when an instruction attempts to push NPUSHED bytes. 27243 27244 On some machines, the definition 27245 27246 #define PUSH_ROUNDING(BYTES) (BYTES) 27247 27248 will suffice. But on other machines, instructions that appear to 27249 push one byte actually push two bytes in an attempt to maintain 27250 alignment. Then the definition should be 27251 27252 #define PUSH_ROUNDING(BYTES) (((BYTES) + 1) & ~1) 27253 27254 -- Macro: ACCUMULATE_OUTGOING_ARGS 27255 A C expression. If nonzero, the maximum amount of space required 27256 for outgoing arguments will be computed and placed into the 27257 variable `current_function_outgoing_args_size'. No space will be 27258 pushed onto the stack for each call; instead, the function 27259 prologue should increase the stack frame size by this amount. 27260 27261 Setting both `PUSH_ARGS' and `ACCUMULATE_OUTGOING_ARGS' is not 27262 proper. 27263 27264 -- Macro: REG_PARM_STACK_SPACE (FNDECL) 27265 Define this macro if functions should assume that stack space has 27266 been allocated for arguments even when their values are passed in 27267 registers. 27268 27269 The value of this macro is the size, in bytes, of the area 27270 reserved for arguments passed in registers for the function 27271 represented by FNDECL, which can be zero if GCC is calling a 27272 library function. The argument FNDECL can be the FUNCTION_DECL, 27273 or the type itself of the function. 27274 27275 This space can be allocated by the caller, or be a part of the 27276 machine-dependent stack frame: `OUTGOING_REG_PARM_STACK_SPACE' says 27277 which. 27278 27279 -- Macro: OUTGOING_REG_PARM_STACK_SPACE (FNTYPE) 27280 Define this to a nonzero value if it is the responsibility of the 27281 caller to allocate the area reserved for arguments passed in 27282 registers when calling a function of FNTYPE. FNTYPE may be NULL 27283 if the function called is a library function. 27284 27285 If `ACCUMULATE_OUTGOING_ARGS' is defined, this macro controls 27286 whether the space for these arguments counts in the value of 27287 `current_function_outgoing_args_size'. 27288 27289 -- Macro: STACK_PARMS_IN_REG_PARM_AREA 27290 Define this macro if `REG_PARM_STACK_SPACE' is defined, but the 27291 stack parameters don't skip the area specified by it. 27292 27293 Normally, when a parameter is not passed in registers, it is 27294 placed on the stack beyond the `REG_PARM_STACK_SPACE' area. 27295 Defining this macro suppresses this behavior and causes the 27296 parameter to be passed on the stack in its natural location. 27297 27298 -- Macro: RETURN_POPS_ARGS (FUNDECL, FUNTYPE, STACK-SIZE) 27299 A C expression that should indicate the number of bytes of its own 27300 arguments that a function pops on returning, or 0 if the function 27301 pops no arguments and the caller must therefore pop them all after 27302 the function returns. 27303 27304 FUNDECL is a C variable whose value is a tree node that describes 27305 the function in question. Normally it is a node of type 27306 `FUNCTION_DECL' that describes the declaration of the function. 27307 From this you can obtain the `DECL_ATTRIBUTES' of the function. 27308 27309 FUNTYPE is a C variable whose value is a tree node that describes 27310 the function in question. Normally it is a node of type 27311 `FUNCTION_TYPE' that describes the data type of the function. 27312 From this it is possible to obtain the data types of the value and 27313 arguments (if known). 27314 27315 When a call to a library function is being considered, FUNDECL 27316 will contain an identifier node for the library function. Thus, if 27317 you need to distinguish among various library functions, you can 27318 do so by their names. Note that "library function" in this 27319 context means a function used to perform arithmetic, whose name is 27320 known specially in the compiler and was not mentioned in the C 27321 code being compiled. 27322 27323 STACK-SIZE is the number of bytes of arguments passed on the 27324 stack. If a variable number of bytes is passed, it is zero, and 27325 argument popping will always be the responsibility of the calling 27326 function. 27327 27328 On the VAX, all functions always pop their arguments, so the 27329 definition of this macro is STACK-SIZE. On the 68000, using the 27330 standard calling convention, no functions pop their arguments, so 27331 the value of the macro is always 0 in this case. But an 27332 alternative calling convention is available in which functions 27333 that take a fixed number of arguments pop them but other functions 27334 (such as `printf') pop nothing (the caller pops all). When this 27335 convention is in use, FUNTYPE is examined to determine whether a 27336 function takes a fixed number of arguments. 27337 27338 -- Macro: CALL_POPS_ARGS (CUM) 27339 A C expression that should indicate the number of bytes a call 27340 sequence pops off the stack. It is added to the value of 27341 `RETURN_POPS_ARGS' when compiling a function call. 27342 27343 CUM is the variable in which all arguments to the called function 27344 have been accumulated. 27345 27346 On certain architectures, such as the SH5, a call trampoline is 27347 used that pops certain registers off the stack, depending on the 27348 arguments that have been passed to the function. Since this is a 27349 property of the call site, not of the called function, 27350 `RETURN_POPS_ARGS' is not appropriate. 27351 27352 27353 File: gccint.info, Node: Register Arguments, Next: Scalar Return, Prev: Stack Arguments, Up: Stack and Calling 27354 27355 17.10.7 Passing Arguments in Registers 27356 -------------------------------------- 27357 27358 This section describes the macros which let you control how various 27359 types of arguments are passed in registers or how they are arranged in 27360 the stack. 27361 27362 -- Macro: FUNCTION_ARG (CUM, MODE, TYPE, NAMED) 27363 A C expression that controls whether a function argument is passed 27364 in a register, and which register. 27365 27366 The arguments are CUM, which summarizes all the previous 27367 arguments; MODE, the machine mode of the argument; TYPE, the data 27368 type of the argument as a tree node or 0 if that is not known 27369 (which happens for C support library functions); and NAMED, which 27370 is 1 for an ordinary argument and 0 for nameless arguments that 27371 correspond to `...' in the called function's prototype. TYPE can 27372 be an incomplete type if a syntax error has previously occurred. 27373 27374 The value of the expression is usually either a `reg' RTX for the 27375 hard register in which to pass the argument, or zero to pass the 27376 argument on the stack. 27377 27378 For machines like the VAX and 68000, where normally all arguments 27379 are pushed, zero suffices as a definition. 27380 27381 The value of the expression can also be a `parallel' RTX. This is 27382 used when an argument is passed in multiple locations. The mode 27383 of the `parallel' should be the mode of the entire argument. The 27384 `parallel' holds any number of `expr_list' pairs; each one 27385 describes where part of the argument is passed. In each 27386 `expr_list' the first operand must be a `reg' RTX for the hard 27387 register in which to pass this part of the argument, and the mode 27388 of the register RTX indicates how large this part of the argument 27389 is. The second operand of the `expr_list' is a `const_int' which 27390 gives the offset in bytes into the entire argument of where this 27391 part starts. As a special exception the first `expr_list' in the 27392 `parallel' RTX may have a first operand of zero. This indicates 27393 that the entire argument is also stored on the stack. 27394 27395 The last time this macro is called, it is called with `MODE == 27396 VOIDmode', and its result is passed to the `call' or `call_value' 27397 pattern as operands 2 and 3 respectively. 27398 27399 The usual way to make the ISO library `stdarg.h' work on a machine 27400 where some arguments are usually passed in registers, is to cause 27401 nameless arguments to be passed on the stack instead. This is done 27402 by making `FUNCTION_ARG' return 0 whenever NAMED is 0. 27403 27404 You may use the hook `targetm.calls.must_pass_in_stack' in the 27405 definition of this macro to determine if this argument is of a 27406 type that must be passed in the stack. If `REG_PARM_STACK_SPACE' 27407 is not defined and `FUNCTION_ARG' returns nonzero for such an 27408 argument, the compiler will abort. If `REG_PARM_STACK_SPACE' is 27409 defined, the argument will be computed in the stack and then 27410 loaded into a register. 27411 27412 -- Target Hook: bool TARGET_MUST_PASS_IN_STACK (enum machine_mode 27413 MODE, tree TYPE) 27414 This target hook should return `true' if we should not pass TYPE 27415 solely in registers. The file `expr.h' defines a definition that 27416 is usually appropriate, refer to `expr.h' for additional 27417 documentation. 27418 27419 -- Macro: FUNCTION_INCOMING_ARG (CUM, MODE, TYPE, NAMED) 27420 Define this macro if the target machine has "register windows", so 27421 that the register in which a function sees an arguments is not 27422 necessarily the same as the one in which the caller passed the 27423 argument. 27424 27425 For such machines, `FUNCTION_ARG' computes the register in which 27426 the caller passes the value, and `FUNCTION_INCOMING_ARG' should be 27427 defined in a similar fashion to tell the function being called 27428 where the arguments will arrive. 27429 27430 If `FUNCTION_INCOMING_ARG' is not defined, `FUNCTION_ARG' serves 27431 both purposes. 27432 27433 -- Target Hook: int TARGET_ARG_PARTIAL_BYTES (CUMULATIVE_ARGS *CUM, 27434 enum machine_mode MODE, tree TYPE, bool NAMED) 27435 This target hook returns the number of bytes at the beginning of an 27436 argument that must be put in registers. The value must be zero for 27437 arguments that are passed entirely in registers or that are 27438 entirely pushed on the stack. 27439 27440 On some machines, certain arguments must be passed partially in 27441 registers and partially in memory. On these machines, typically 27442 the first few words of arguments are passed in registers, and the 27443 rest on the stack. If a multi-word argument (a `double' or a 27444 structure) crosses that boundary, its first few words must be 27445 passed in registers and the rest must be pushed. This macro tells 27446 the compiler when this occurs, and how many bytes should go in 27447 registers. 27448 27449 `FUNCTION_ARG' for these arguments should return the first 27450 register to be used by the caller for this argument; likewise 27451 `FUNCTION_INCOMING_ARG', for the called function. 27452 27453 -- Target Hook: bool TARGET_PASS_BY_REFERENCE (CUMULATIVE_ARGS *CUM, 27454 enum machine_mode MODE, tree TYPE, bool NAMED) 27455 This target hook should return `true' if an argument at the 27456 position indicated by CUM should be passed by reference. This 27457 predicate is queried after target independent reasons for being 27458 passed by reference, such as `TREE_ADDRESSABLE (type)'. 27459 27460 If the hook returns true, a copy of that argument is made in 27461 memory and a pointer to the argument is passed instead of the 27462 argument itself. The pointer is passed in whatever way is 27463 appropriate for passing a pointer to that type. 27464 27465 -- Target Hook: bool TARGET_CALLEE_COPIES (CUMULATIVE_ARGS *CUM, enum 27466 machine_mode MODE, tree TYPE, bool NAMED) 27467 The function argument described by the parameters to this hook is 27468 known to be passed by reference. The hook should return true if 27469 the function argument should be copied by the callee instead of 27470 copied by the caller. 27471 27472 For any argument for which the hook returns true, if it can be 27473 determined that the argument is not modified, then a copy need not 27474 be generated. 27475 27476 The default version of this hook always returns false. 27477 27478 -- Macro: CUMULATIVE_ARGS 27479 A C type for declaring a variable that is used as the first 27480 argument of `FUNCTION_ARG' and other related values. For some 27481 target machines, the type `int' suffices and can hold the number 27482 of bytes of argument so far. 27483 27484 There is no need to record in `CUMULATIVE_ARGS' anything about the 27485 arguments that have been passed on the stack. The compiler has 27486 other variables to keep track of that. For target machines on 27487 which all arguments are passed on the stack, there is no need to 27488 store anything in `CUMULATIVE_ARGS'; however, the data structure 27489 must exist and should not be empty, so use `int'. 27490 27491 -- Macro: OVERRIDE_ABI_FORMAT (FNDECL) 27492 If defined, this macro is called before generating any code for a 27493 function, but after the CFUN descriptor for the function has been 27494 created. The back end may use this macro to update CFUN to 27495 reflect an ABI other than that which would normally be used by 27496 default. If the compiler is generating code for a 27497 compiler-generated function, FNDECL may be `NULL'. 27498 27499 -- Macro: INIT_CUMULATIVE_ARGS (CUM, FNTYPE, LIBNAME, FNDECL, 27500 N_NAMED_ARGS) 27501 A C statement (sans semicolon) for initializing the variable CUM 27502 for the state at the beginning of the argument list. The variable 27503 has type `CUMULATIVE_ARGS'. The value of FNTYPE is the tree node 27504 for the data type of the function which will receive the args, or 27505 0 if the args are to a compiler support library function. For 27506 direct calls that are not libcalls, FNDECL contain the declaration 27507 node of the function. FNDECL is also set when 27508 `INIT_CUMULATIVE_ARGS' is used to find arguments for the function 27509 being compiled. N_NAMED_ARGS is set to the number of named 27510 arguments, including a structure return address if it is passed as 27511 a parameter, when making a call. When processing incoming 27512 arguments, N_NAMED_ARGS is set to -1. 27513 27514 When processing a call to a compiler support library function, 27515 LIBNAME identifies which one. It is a `symbol_ref' rtx which 27516 contains the name of the function, as a string. LIBNAME is 0 when 27517 an ordinary C function call is being processed. Thus, each time 27518 this macro is called, either LIBNAME or FNTYPE is nonzero, but 27519 never both of them at once. 27520 27521 -- Macro: INIT_CUMULATIVE_LIBCALL_ARGS (CUM, MODE, LIBNAME) 27522 Like `INIT_CUMULATIVE_ARGS' but only used for outgoing libcalls, 27523 it gets a `MODE' argument instead of FNTYPE, that would be `NULL'. 27524 INDIRECT would always be zero, too. If this macro is not 27525 defined, `INIT_CUMULATIVE_ARGS (cum, NULL_RTX, libname, 0)' is 27526 used instead. 27527 27528 -- Macro: INIT_CUMULATIVE_INCOMING_ARGS (CUM, FNTYPE, LIBNAME) 27529 Like `INIT_CUMULATIVE_ARGS' but overrides it for the purposes of 27530 finding the arguments for the function being compiled. If this 27531 macro is undefined, `INIT_CUMULATIVE_ARGS' is used instead. 27532 27533 The value passed for LIBNAME is always 0, since library routines 27534 with special calling conventions are never compiled with GCC. The 27535 argument LIBNAME exists for symmetry with `INIT_CUMULATIVE_ARGS'. 27536 27537 -- Macro: FUNCTION_ARG_ADVANCE (CUM, MODE, TYPE, NAMED) 27538 A C statement (sans semicolon) to update the summarizer variable 27539 CUM to advance past an argument in the argument list. The values 27540 MODE, TYPE and NAMED describe that argument. Once this is done, 27541 the variable CUM is suitable for analyzing the _following_ 27542 argument with `FUNCTION_ARG', etc. 27543 27544 This macro need not do anything if the argument in question was 27545 passed on the stack. The compiler knows how to track the amount 27546 of stack space used for arguments without any special help. 27547 27548 -- Macro: FUNCTION_ARG_OFFSET (MODE, TYPE) 27549 If defined, a C expression that is the number of bytes to add to 27550 the offset of the argument passed in memory. This is needed for 27551 the SPU, which passes `char' and `short' arguments in the preferred 27552 slot that is in the middle of the quad word instead of starting at 27553 the top. 27554 27555 -- Macro: FUNCTION_ARG_PADDING (MODE, TYPE) 27556 If defined, a C expression which determines whether, and in which 27557 direction, to pad out an argument with extra space. The value 27558 should be of type `enum direction': either `upward' to pad above 27559 the argument, `downward' to pad below, or `none' to inhibit 27560 padding. 27561 27562 The _amount_ of padding is always just enough to reach the next 27563 multiple of `FUNCTION_ARG_BOUNDARY'; this macro does not control 27564 it. 27565 27566 This macro has a default definition which is right for most 27567 systems. For little-endian machines, the default is to pad 27568 upward. For big-endian machines, the default is to pad downward 27569 for an argument of constant size shorter than an `int', and upward 27570 otherwise. 27571 27572 -- Macro: PAD_VARARGS_DOWN 27573 If defined, a C expression which determines whether the default 27574 implementation of va_arg will attempt to pad down before reading 27575 the next argument, if that argument is smaller than its aligned 27576 space as controlled by `PARM_BOUNDARY'. If this macro is not 27577 defined, all such arguments are padded down if `BYTES_BIG_ENDIAN' 27578 is true. 27579 27580 -- Macro: BLOCK_REG_PADDING (MODE, TYPE, FIRST) 27581 Specify padding for the last element of a block move between 27582 registers and memory. FIRST is nonzero if this is the only 27583 element. Defining this macro allows better control of register 27584 function parameters on big-endian machines, without using 27585 `PARALLEL' rtl. In particular, `MUST_PASS_IN_STACK' need not test 27586 padding and mode of types in registers, as there is no longer a 27587 "wrong" part of a register; For example, a three byte aggregate 27588 may be passed in the high part of a register if so required. 27589 27590 -- Macro: FUNCTION_ARG_BOUNDARY (MODE, TYPE) 27591 If defined, a C expression that gives the alignment boundary, in 27592 bits, of an argument with the specified mode and type. If it is 27593 not defined, `PARM_BOUNDARY' is used for all arguments. 27594 27595 -- Macro: FUNCTION_ARG_REGNO_P (REGNO) 27596 A C expression that is nonzero if REGNO is the number of a hard 27597 register in which function arguments are sometimes passed. This 27598 does _not_ include implicit arguments such as the static chain and 27599 the structure-value address. On many machines, no registers can be 27600 used for this purpose since all function arguments are pushed on 27601 the stack. 27602 27603 -- Target Hook: bool TARGET_SPLIT_COMPLEX_ARG (tree TYPE) 27604 This hook should return true if parameter of type TYPE are passed 27605 as two scalar parameters. By default, GCC will attempt to pack 27606 complex arguments into the target's word size. Some ABIs require 27607 complex arguments to be split and treated as their individual 27608 components. For example, on AIX64, complex floats should be 27609 passed in a pair of floating point registers, even though a 27610 complex float would fit in one 64-bit floating point register. 27611 27612 The default value of this hook is `NULL', which is treated as 27613 always false. 27614 27615 -- Target Hook: tree TARGET_BUILD_BUILTIN_VA_LIST (void) 27616 This hook returns a type node for `va_list' for the target. The 27617 default version of the hook returns `void*'. 27618 27619 -- Target Hook: tree TARGET_FN_ABI_VA_LIST (tree FNDECL) 27620 This hook returns the va_list type of the calling convention 27621 specified by FNDECL. The default version of this hook returns 27622 `va_list_type_node'. 27623 27624 -- Target Hook: tree TARGET_CANONICAL_VA_LIST_TYPE (tree TYPE) 27625 This hook returns the va_list type of the calling convention 27626 specified by the type of TYPE. If TYPE is not a valid va_list 27627 type, it returns `NULL_TREE'. 27628 27629 -- Target Hook: tree TARGET_GIMPLIFY_VA_ARG_EXPR (tree VALIST, tree 27630 TYPE, tree *PRE_P, tree *POST_P) 27631 This hook performs target-specific gimplification of 27632 `VA_ARG_EXPR'. The first two parameters correspond to the 27633 arguments to `va_arg'; the latter two are as in 27634 `gimplify.c:gimplify_expr'. 27635 27636 -- Target Hook: bool TARGET_VALID_POINTER_MODE (enum machine_mode MODE) 27637 Define this to return nonzero if the port can handle pointers with 27638 machine mode MODE. The default version of this hook returns true 27639 for both `ptr_mode' and `Pmode'. 27640 27641 -- Target Hook: bool TARGET_SCALAR_MODE_SUPPORTED_P (enum machine_mode 27642 MODE) 27643 Define this to return nonzero if the port is prepared to handle 27644 insns involving scalar mode MODE. For a scalar mode to be 27645 considered supported, all the basic arithmetic and comparisons 27646 must work. 27647 27648 The default version of this hook returns true for any mode 27649 required to handle the basic C types (as defined by the port). 27650 Included here are the double-word arithmetic supported by the code 27651 in `optabs.c'. 27652 27653 -- Target Hook: bool TARGET_VECTOR_MODE_SUPPORTED_P (enum machine_mode 27654 MODE) 27655 Define this to return nonzero if the port is prepared to handle 27656 insns involving vector mode MODE. At the very least, it must have 27657 move patterns for this mode. 27658 27659 27660 File: gccint.info, Node: Scalar Return, Next: Aggregate Return, Prev: Register Arguments, Up: Stack and Calling 27661 27662 17.10.8 How Scalar Function Values Are Returned 27663 ----------------------------------------------- 27664 27665 This section discusses the macros that control returning scalars as 27666 values--values that can fit in registers. 27667 27668 -- Target Hook: rtx TARGET_FUNCTION_VALUE (tree RET_TYPE, tree 27669 FN_DECL_OR_TYPE, bool OUTGOING) 27670 Define this to return an RTX representing the place where a 27671 function returns or receives a value of data type RET_TYPE, a tree 27672 node node representing a data type. FN_DECL_OR_TYPE is a tree node 27673 representing `FUNCTION_DECL' or `FUNCTION_TYPE' of a function 27674 being called. If OUTGOING is false, the hook should compute the 27675 register in which the caller will see the return value. 27676 Otherwise, the hook should return an RTX representing the place 27677 where a function returns a value. 27678 27679 On many machines, only `TYPE_MODE (RET_TYPE)' is relevant. 27680 (Actually, on most machines, scalar values are returned in the same 27681 place regardless of mode.) The value of the expression is usually 27682 a `reg' RTX for the hard register where the return value is stored. 27683 The value can also be a `parallel' RTX, if the return value is in 27684 multiple places. See `FUNCTION_ARG' for an explanation of the 27685 `parallel' form. Note that the callee will populate every 27686 location specified in the `parallel', but if the first element of 27687 the `parallel' contains the whole return value, callers will use 27688 that element as the canonical location and ignore the others. The 27689 m68k port uses this type of `parallel' to return pointers in both 27690 `%a0' (the canonical location) and `%d0'. 27691 27692 If `TARGET_PROMOTE_FUNCTION_RETURN' returns true, you must apply 27693 the same promotion rules specified in `PROMOTE_MODE' if VALTYPE is 27694 a scalar type. 27695 27696 If the precise function being called is known, FUNC is a tree node 27697 (`FUNCTION_DECL') for it; otherwise, FUNC is a null pointer. This 27698 makes it possible to use a different value-returning convention 27699 for specific functions when all their calls are known. 27700 27701 Some target machines have "register windows" so that the register 27702 in which a function returns its value is not the same as the one 27703 in which the caller sees the value. For such machines, you should 27704 return different RTX depending on OUTGOING. 27705 27706 `TARGET_FUNCTION_VALUE' is not used for return values with 27707 aggregate data types, because these are returned in another way. 27708 See `TARGET_STRUCT_VALUE_RTX' and related macros, below. 27709 27710 -- Macro: FUNCTION_VALUE (VALTYPE, FUNC) 27711 This macro has been deprecated. Use `TARGET_FUNCTION_VALUE' for a 27712 new target instead. 27713 27714 -- Macro: FUNCTION_OUTGOING_VALUE (VALTYPE, FUNC) 27715 This macro has been deprecated. Use `TARGET_FUNCTION_VALUE' for a 27716 new target instead. 27717 27718 -- Macro: LIBCALL_VALUE (MODE) 27719 A C expression to create an RTX representing the place where a 27720 library function returns a value of mode MODE. 27721 27722 Note that "library function" in this context means a compiler 27723 support routine, used to perform arithmetic, whose name is known 27724 specially by the compiler and was not mentioned in the C code being 27725 compiled. 27726 27727 -- Macro: FUNCTION_VALUE_REGNO_P (REGNO) 27728 A C expression that is nonzero if REGNO is the number of a hard 27729 register in which the values of called function may come back. 27730 27731 A register whose use for returning values is limited to serving as 27732 the second of a pair (for a value of type `double', say) need not 27733 be recognized by this macro. So for most machines, this definition 27734 suffices: 27735 27736 #define FUNCTION_VALUE_REGNO_P(N) ((N) == 0) 27737 27738 If the machine has register windows, so that the caller and the 27739 called function use different registers for the return value, this 27740 macro should recognize only the caller's register numbers. 27741 27742 -- Macro: TARGET_ENUM_VA_LIST (IDX, PNAME, PTYPE) 27743 This target macro is used in function `c_common_nodes_and_builtins' 27744 to iterate through the target specific builtin types for va_list. 27745 The variable IDX is used as iterator. PNAME has to be a pointer to 27746 a `const char *' and PTYPE a pointer to a `tree' typed variable. 27747 The arguments PNAME and PTYPE are used to store the result of this 27748 macro and are set to the name of the va_list builtin type and its 27749 internal type. If the return value of this macro is zero, then 27750 there is no more element. Otherwise the IDX should be increased 27751 for the next call of this macro to iterate through all types. 27752 27753 -- Macro: APPLY_RESULT_SIZE 27754 Define this macro if `untyped_call' and `untyped_return' need more 27755 space than is implied by `FUNCTION_VALUE_REGNO_P' for saving and 27756 restoring an arbitrary return value. 27757 27758 -- Target Hook: bool TARGET_RETURN_IN_MSB (tree TYPE) 27759 This hook should return true if values of type TYPE are returned 27760 at the most significant end of a register (in other words, if they 27761 are padded at the least significant end). You can assume that TYPE 27762 is returned in a register; the caller is required to check this. 27763 27764 Note that the register provided by `TARGET_FUNCTION_VALUE' must be 27765 able to hold the complete return value. For example, if a 1-, 2- 27766 or 3-byte structure is returned at the most significant end of a 27767 4-byte register, `TARGET_FUNCTION_VALUE' should provide an 27768 `SImode' rtx. 27769 27770 27771 File: gccint.info, Node: Aggregate Return, Next: Caller Saves, Prev: Scalar Return, Up: Stack and Calling 27772 27773 17.10.9 How Large Values Are Returned 27774 ------------------------------------- 27775 27776 When a function value's mode is `BLKmode' (and in some other cases), 27777 the value is not returned according to `TARGET_FUNCTION_VALUE' (*note 27778 Scalar Return::). Instead, the caller passes the address of a block of 27779 memory in which the value should be stored. This address is called the 27780 "structure value address". 27781 27782 This section describes how to control returning structure values in 27783 memory. 27784 27785 -- Target Hook: bool TARGET_RETURN_IN_MEMORY (tree TYPE, tree FNTYPE) 27786 This target hook should return a nonzero value to say to return the 27787 function value in memory, just as large structures are always 27788 returned. Here TYPE will be the data type of the value, and FNTYPE 27789 will be the type of the function doing the returning, or `NULL' for 27790 libcalls. 27791 27792 Note that values of mode `BLKmode' must be explicitly handled by 27793 this function. Also, the option `-fpcc-struct-return' takes 27794 effect regardless of this macro. On most systems, it is possible 27795 to leave the hook undefined; this causes a default definition to 27796 be used, whose value is the constant 1 for `BLKmode' values, and 0 27797 otherwise. 27798 27799 Do not use this hook to indicate that structures and unions should 27800 always be returned in memory. You should instead use 27801 `DEFAULT_PCC_STRUCT_RETURN' to indicate this. 27802 27803 -- Macro: DEFAULT_PCC_STRUCT_RETURN 27804 Define this macro to be 1 if all structure and union return values 27805 must be in memory. Since this results in slower code, this should 27806 be defined only if needed for compatibility with other compilers 27807 or with an ABI. If you define this macro to be 0, then the 27808 conventions used for structure and union return values are decided 27809 by the `TARGET_RETURN_IN_MEMORY' target hook. 27810 27811 If not defined, this defaults to the value 1. 27812 27813 -- Target Hook: rtx TARGET_STRUCT_VALUE_RTX (tree FNDECL, int INCOMING) 27814 This target hook should return the location of the structure value 27815 address (normally a `mem' or `reg'), or 0 if the address is passed 27816 as an "invisible" first argument. Note that FNDECL may be `NULL', 27817 for libcalls. You do not need to define this target hook if the 27818 address is always passed as an "invisible" first argument. 27819 27820 On some architectures the place where the structure value address 27821 is found by the called function is not the same place that the 27822 caller put it. This can be due to register windows, or it could 27823 be because the function prologue moves it to a different place. 27824 INCOMING is `1' or `2' when the location is needed in the context 27825 of the called function, and `0' in the context of the caller. 27826 27827 If INCOMING is nonzero and the address is to be found on the 27828 stack, return a `mem' which refers to the frame pointer. If 27829 INCOMING is `2', the result is being used to fetch the structure 27830 value address at the beginning of a function. If you need to emit 27831 adjusting code, you should do it at this point. 27832 27833 -- Macro: PCC_STATIC_STRUCT_RETURN 27834 Define this macro if the usual system convention on the target 27835 machine for returning structures and unions is for the called 27836 function to return the address of a static variable containing the 27837 value. 27838 27839 Do not define this if the usual system convention is for the 27840 caller to pass an address to the subroutine. 27841 27842 This macro has effect in `-fpcc-struct-return' mode, but it does 27843 nothing when you use `-freg-struct-return' mode. 27844 27845 27846 File: gccint.info, Node: Caller Saves, Next: Function Entry, Prev: Aggregate Return, Up: Stack and Calling 27847 27848 17.10.10 Caller-Saves Register Allocation 27849 ----------------------------------------- 27850 27851 If you enable it, GCC can save registers around function calls. This 27852 makes it possible to use call-clobbered registers to hold variables that 27853 must live across calls. 27854 27855 -- Macro: CALLER_SAVE_PROFITABLE (REFS, CALLS) 27856 A C expression to determine whether it is worthwhile to consider 27857 placing a pseudo-register in a call-clobbered hard register and 27858 saving and restoring it around each function call. The expression 27859 should be 1 when this is worth doing, and 0 otherwise. 27860 27861 If you don't define this macro, a default is used which is good on 27862 most machines: `4 * CALLS < REFS'. 27863 27864 -- Macro: HARD_REGNO_CALLER_SAVE_MODE (REGNO, NREGS) 27865 A C expression specifying which mode is required for saving NREGS 27866 of a pseudo-register in call-clobbered hard register REGNO. If 27867 REGNO is unsuitable for caller save, `VOIDmode' should be 27868 returned. For most machines this macro need not be defined since 27869 GCC will select the smallest suitable mode. 27870 27871 27872 File: gccint.info, Node: Function Entry, Next: Profiling, Prev: Caller Saves, Up: Stack and Calling 27873 27874 17.10.11 Function Entry and Exit 27875 -------------------------------- 27876 27877 This section describes the macros that output function entry 27878 ("prologue") and exit ("epilogue") code. 27879 27880 -- Target Hook: void TARGET_ASM_FUNCTION_PROLOGUE (FILE *FILE, 27881 HOST_WIDE_INT SIZE) 27882 If defined, a function that outputs the assembler code for entry 27883 to a function. The prologue is responsible for setting up the 27884 stack frame, initializing the frame pointer register, saving 27885 registers that must be saved, and allocating SIZE additional bytes 27886 of storage for the local variables. SIZE is an integer. FILE is 27887 a stdio stream to which the assembler code should be output. 27888 27889 The label for the beginning of the function need not be output by 27890 this macro. That has already been done when the macro is run. 27891 27892 To determine which registers to save, the macro can refer to the 27893 array `regs_ever_live': element R is nonzero if hard register R is 27894 used anywhere within the function. This implies the function 27895 prologue should save register R, provided it is not one of the 27896 call-used registers. (`TARGET_ASM_FUNCTION_EPILOGUE' must 27897 likewise use `regs_ever_live'.) 27898 27899 On machines that have "register windows", the function entry code 27900 does not save on the stack the registers that are in the windows, 27901 even if they are supposed to be preserved by function calls; 27902 instead it takes appropriate steps to "push" the register stack, 27903 if any non-call-used registers are used in the function. 27904 27905 On machines where functions may or may not have frame-pointers, the 27906 function entry code must vary accordingly; it must set up the frame 27907 pointer if one is wanted, and not otherwise. To determine whether 27908 a frame pointer is in wanted, the macro can refer to the variable 27909 `frame_pointer_needed'. The variable's value will be 1 at run 27910 time in a function that needs a frame pointer. *Note 27911 Elimination::. 27912 27913 The function entry code is responsible for allocating any stack 27914 space required for the function. This stack space consists of the 27915 regions listed below. In most cases, these regions are allocated 27916 in the order listed, with the last listed region closest to the 27917 top of the stack (the lowest address if `STACK_GROWS_DOWNWARD' is 27918 defined, and the highest address if it is not defined). You can 27919 use a different order for a machine if doing so is more convenient 27920 or required for compatibility reasons. Except in cases where 27921 required by standard or by a debugger, there is no reason why the 27922 stack layout used by GCC need agree with that used by other 27923 compilers for a machine. 27924 27925 -- Target Hook: void TARGET_ASM_FUNCTION_END_PROLOGUE (FILE *FILE) 27926 If defined, a function that outputs assembler code at the end of a 27927 prologue. This should be used when the function prologue is being 27928 emitted as RTL, and you have some extra assembler that needs to be 27929 emitted. *Note prologue instruction pattern::. 27930 27931 -- Target Hook: void TARGET_ASM_FUNCTION_BEGIN_EPILOGUE (FILE *FILE) 27932 If defined, a function that outputs assembler code at the start of 27933 an epilogue. This should be used when the function epilogue is 27934 being emitted as RTL, and you have some extra assembler that needs 27935 to be emitted. *Note epilogue instruction pattern::. 27936 27937 -- Target Hook: void TARGET_ASM_FUNCTION_EPILOGUE (FILE *FILE, 27938 HOST_WIDE_INT SIZE) 27939 If defined, a function that outputs the assembler code for exit 27940 from a function. The epilogue is responsible for restoring the 27941 saved registers and stack pointer to their values when the 27942 function was called, and returning control to the caller. This 27943 macro takes the same arguments as the macro 27944 `TARGET_ASM_FUNCTION_PROLOGUE', and the registers to restore are 27945 determined from `regs_ever_live' and `CALL_USED_REGISTERS' in the 27946 same way. 27947 27948 On some machines, there is a single instruction that does all the 27949 work of returning from the function. On these machines, give that 27950 instruction the name `return' and do not define the macro 27951 `TARGET_ASM_FUNCTION_EPILOGUE' at all. 27952 27953 Do not define a pattern named `return' if you want the 27954 `TARGET_ASM_FUNCTION_EPILOGUE' to be used. If you want the target 27955 switches to control whether return instructions or epilogues are 27956 used, define a `return' pattern with a validity condition that 27957 tests the target switches appropriately. If the `return' 27958 pattern's validity condition is false, epilogues will be used. 27959 27960 On machines where functions may or may not have frame-pointers, the 27961 function exit code must vary accordingly. Sometimes the code for 27962 these two cases is completely different. To determine whether a 27963 frame pointer is wanted, the macro can refer to the variable 27964 `frame_pointer_needed'. The variable's value will be 1 when 27965 compiling a function that needs a frame pointer. 27966 27967 Normally, `TARGET_ASM_FUNCTION_PROLOGUE' and 27968 `TARGET_ASM_FUNCTION_EPILOGUE' must treat leaf functions specially. 27969 The C variable `current_function_is_leaf' is nonzero for such a 27970 function. *Note Leaf Functions::. 27971 27972 On some machines, some functions pop their arguments on exit while 27973 others leave that for the caller to do. For example, the 68020 27974 when given `-mrtd' pops arguments in functions that take a fixed 27975 number of arguments. 27976 27977 Your definition of the macro `RETURN_POPS_ARGS' decides which 27978 functions pop their own arguments. `TARGET_ASM_FUNCTION_EPILOGUE' 27979 needs to know what was decided. The variable that is called 27980 `current_function_pops_args' is the number of bytes of its 27981 arguments that a function should pop. *Note Scalar Return::. 27982 27983 * A region of `current_function_pretend_args_size' bytes of 27984 uninitialized space just underneath the first argument arriving on 27985 the stack. (This may not be at the very start of the allocated 27986 stack region if the calling sequence has pushed anything else 27987 since pushing the stack arguments. But usually, on such machines, 27988 nothing else has been pushed yet, because the function prologue 27989 itself does all the pushing.) This region is used on machines 27990 where an argument may be passed partly in registers and partly in 27991 memory, and, in some cases to support the features in `<stdarg.h>'. 27992 27993 * An area of memory used to save certain registers used by the 27994 function. The size of this area, which may also include space for 27995 such things as the return address and pointers to previous stack 27996 frames, is machine-specific and usually depends on which registers 27997 have been used in the function. Machines with register windows 27998 often do not require a save area. 27999 28000 * A region of at least SIZE bytes, possibly rounded up to an 28001 allocation boundary, to contain the local variables of the 28002 function. On some machines, this region and the save area may 28003 occur in the opposite order, with the save area closer to the top 28004 of the stack. 28005 28006 * Optionally, when `ACCUMULATE_OUTGOING_ARGS' is defined, a region of 28007 `current_function_outgoing_args_size' bytes to be used for outgoing 28008 argument lists of the function. *Note Stack Arguments::. 28009 28010 -- Macro: EXIT_IGNORE_STACK 28011 Define this macro as a C expression that is nonzero if the return 28012 instruction or the function epilogue ignores the value of the stack 28013 pointer; in other words, if it is safe to delete an instruction to 28014 adjust the stack pointer before a return from the function. The 28015 default is 0. 28016 28017 Note that this macro's value is relevant only for functions for 28018 which frame pointers are maintained. It is never safe to delete a 28019 final stack adjustment in a function that has no frame pointer, 28020 and the compiler knows this regardless of `EXIT_IGNORE_STACK'. 28021 28022 -- Macro: EPILOGUE_USES (REGNO) 28023 Define this macro as a C expression that is nonzero for registers 28024 that are used by the epilogue or the `return' pattern. The stack 28025 and frame pointer registers are already assumed to be used as 28026 needed. 28027 28028 -- Macro: EH_USES (REGNO) 28029 Define this macro as a C expression that is nonzero for registers 28030 that are used by the exception handling mechanism, and so should 28031 be considered live on entry to an exception edge. 28032 28033 -- Macro: DELAY_SLOTS_FOR_EPILOGUE 28034 Define this macro if the function epilogue contains delay slots to 28035 which instructions from the rest of the function can be "moved". 28036 The definition should be a C expression whose value is an integer 28037 representing the number of delay slots there. 28038 28039 -- Macro: ELIGIBLE_FOR_EPILOGUE_DELAY (INSN, N) 28040 A C expression that returns 1 if INSN can be placed in delay slot 28041 number N of the epilogue. 28042 28043 The argument N is an integer which identifies the delay slot now 28044 being considered (since different slots may have different rules of 28045 eligibility). It is never negative and is always less than the 28046 number of epilogue delay slots (what `DELAY_SLOTS_FOR_EPILOGUE' 28047 returns). If you reject a particular insn for a given delay slot, 28048 in principle, it may be reconsidered for a subsequent delay slot. 28049 Also, other insns may (at least in principle) be considered for 28050 the so far unfilled delay slot. 28051 28052 The insns accepted to fill the epilogue delay slots are put in an 28053 RTL list made with `insn_list' objects, stored in the variable 28054 `current_function_epilogue_delay_list'. The insn for the first 28055 delay slot comes first in the list. Your definition of the macro 28056 `TARGET_ASM_FUNCTION_EPILOGUE' should fill the delay slots by 28057 outputting the insns in this list, usually by calling 28058 `final_scan_insn'. 28059 28060 You need not define this macro if you did not define 28061 `DELAY_SLOTS_FOR_EPILOGUE'. 28062 28063 -- Target Hook: void TARGET_ASM_OUTPUT_MI_THUNK (FILE *FILE, tree 28064 THUNK_FNDECL, HOST_WIDE_INT DELTA, HOST_WIDE_INT 28065 VCALL_OFFSET, tree FUNCTION) 28066 A function that outputs the assembler code for a thunk function, 28067 used to implement C++ virtual function calls with multiple 28068 inheritance. The thunk acts as a wrapper around a virtual 28069 function, adjusting the implicit object parameter before handing 28070 control off to the real function. 28071 28072 First, emit code to add the integer DELTA to the location that 28073 contains the incoming first argument. Assume that this argument 28074 contains a pointer, and is the one used to pass the `this' pointer 28075 in C++. This is the incoming argument _before_ the function 28076 prologue, e.g. `%o0' on a sparc. The addition must preserve the 28077 values of all other incoming arguments. 28078 28079 Then, if VCALL_OFFSET is nonzero, an additional adjustment should 28080 be made after adding `delta'. In particular, if P is the adjusted 28081 pointer, the following adjustment should be made: 28082 28083 p += (*((ptrdiff_t **)p))[vcall_offset/sizeof(ptrdiff_t)] 28084 28085 After the additions, emit code to jump to FUNCTION, which is a 28086 `FUNCTION_DECL'. This is a direct pure jump, not a call, and does 28087 not touch the return address. Hence returning from FUNCTION will 28088 return to whoever called the current `thunk'. 28089 28090 The effect must be as if FUNCTION had been called directly with 28091 the adjusted first argument. This macro is responsible for 28092 emitting all of the code for a thunk function; 28093 `TARGET_ASM_FUNCTION_PROLOGUE' and `TARGET_ASM_FUNCTION_EPILOGUE' 28094 are not invoked. 28095 28096 The THUNK_FNDECL is redundant. (DELTA and FUNCTION have already 28097 been extracted from it.) It might possibly be useful on some 28098 targets, but probably not. 28099 28100 If you do not define this macro, the target-independent code in 28101 the C++ front end will generate a less efficient heavyweight thunk 28102 that calls FUNCTION instead of jumping to it. The generic 28103 approach does not support varargs. 28104 28105 -- Target Hook: bool TARGET_ASM_CAN_OUTPUT_MI_THUNK (tree 28106 THUNK_FNDECL, HOST_WIDE_INT DELTA, HOST_WIDE_INT 28107 VCALL_OFFSET, tree FUNCTION) 28108 A function that returns true if TARGET_ASM_OUTPUT_MI_THUNK would 28109 be able to output the assembler code for the thunk function 28110 specified by the arguments it is passed, and false otherwise. In 28111 the latter case, the generic approach will be used by the C++ 28112 front end, with the limitations previously exposed. 28113 28114 28115 File: gccint.info, Node: Profiling, Next: Tail Calls, Prev: Function Entry, Up: Stack and Calling 28116 28117 17.10.12 Generating Code for Profiling 28118 -------------------------------------- 28119 28120 These macros will help you generate code for profiling. 28121 28122 -- Macro: FUNCTION_PROFILER (FILE, LABELNO) 28123 A C statement or compound statement to output to FILE some 28124 assembler code to call the profiling subroutine `mcount'. 28125 28126 The details of how `mcount' expects to be called are determined by 28127 your operating system environment, not by GCC. To figure them out, 28128 compile a small program for profiling using the system's installed 28129 C compiler and look at the assembler code that results. 28130 28131 Older implementations of `mcount' expect the address of a counter 28132 variable to be loaded into some register. The name of this 28133 variable is `LP' followed by the number LABELNO, so you would 28134 generate the name using `LP%d' in a `fprintf'. 28135 28136 -- Macro: PROFILE_HOOK 28137 A C statement or compound statement to output to FILE some assembly 28138 code to call the profiling subroutine `mcount' even the target does 28139 not support profiling. 28140 28141 -- Macro: NO_PROFILE_COUNTERS 28142 Define this macro to be an expression with a nonzero value if the 28143 `mcount' subroutine on your system does not need a counter variable 28144 allocated for each function. This is true for almost all modern 28145 implementations. If you define this macro, you must not use the 28146 LABELNO argument to `FUNCTION_PROFILER'. 28147 28148 -- Macro: PROFILE_BEFORE_PROLOGUE 28149 Define this macro if the code for function profiling should come 28150 before the function prologue. Normally, the profiling code comes 28151 after. 28152 28153 28154 File: gccint.info, Node: Tail Calls, Next: Stack Smashing Protection, Prev: Profiling, Up: Stack and Calling 28155 28156 17.10.13 Permitting tail calls 28157 ------------------------------ 28158 28159 -- Target Hook: bool TARGET_FUNCTION_OK_FOR_SIBCALL (tree DECL, tree 28160 EXP) 28161 True if it is ok to do sibling call optimization for the specified 28162 call expression EXP. DECL will be the called function, or `NULL' 28163 if this is an indirect call. 28164 28165 It is not uncommon for limitations of calling conventions to 28166 prevent tail calls to functions outside the current unit of 28167 translation, or during PIC compilation. The hook is used to 28168 enforce these restrictions, as the `sibcall' md pattern can not 28169 fail, or fall over to a "normal" call. The criteria for 28170 successful sibling call optimization may vary greatly between 28171 different architectures. 28172 28173 -- Target Hook: void TARGET_EXTRA_LIVE_ON_ENTRY (bitmap *REGS) 28174 Add any hard registers to REGS that are live on entry to the 28175 function. This hook only needs to be defined to provide registers 28176 that cannot be found by examination of FUNCTION_ARG_REGNO_P, the 28177 callee saved registers, STATIC_CHAIN_INCOMING_REGNUM, 28178 STATIC_CHAIN_REGNUM, TARGET_STRUCT_VALUE_RTX, 28179 FRAME_POINTER_REGNUM, EH_USES, FRAME_POINTER_REGNUM, 28180 ARG_POINTER_REGNUM, and the PIC_OFFSET_TABLE_REGNUM. 28181 28182 28183 File: gccint.info, Node: Stack Smashing Protection, Prev: Tail Calls, Up: Stack and Calling 28184 28185 17.10.14 Stack smashing protection 28186 ---------------------------------- 28187 28188 -- Target Hook: tree TARGET_STACK_PROTECT_GUARD (void) 28189 This hook returns a `DECL' node for the external variable to use 28190 for the stack protection guard. This variable is initialized by 28191 the runtime to some random value and is used to initialize the 28192 guard value that is placed at the top of the local stack frame. 28193 The type of this variable must be `ptr_type_node'. 28194 28195 The default version of this hook creates a variable called 28196 `__stack_chk_guard', which is normally defined in `libgcc2.c'. 28197 28198 -- Target Hook: tree TARGET_STACK_PROTECT_FAIL (void) 28199 This hook returns a tree expression that alerts the runtime that 28200 the stack protect guard variable has been modified. This 28201 expression should involve a call to a `noreturn' function. 28202 28203 The default version of this hook invokes a function called 28204 `__stack_chk_fail', taking no arguments. This function is 28205 normally defined in `libgcc2.c'. 28206 28207 28208 File: gccint.info, Node: Varargs, Next: Trampolines, Prev: Stack and Calling, Up: Target Macros 28209 28210 17.11 Implementing the Varargs Macros 28211 ===================================== 28212 28213 GCC comes with an implementation of `<varargs.h>' and `<stdarg.h>' that 28214 work without change on machines that pass arguments on the stack. 28215 Other machines require their own implementations of varargs, and the 28216 two machine independent header files must have conditionals to include 28217 it. 28218 28219 ISO `<stdarg.h>' differs from traditional `<varargs.h>' mainly in the 28220 calling convention for `va_start'. The traditional implementation 28221 takes just one argument, which is the variable in which to store the 28222 argument pointer. The ISO implementation of `va_start' takes an 28223 additional second argument. The user is supposed to write the last 28224 named argument of the function here. 28225 28226 However, `va_start' should not use this argument. The way to find the 28227 end of the named arguments is with the built-in functions described 28228 below. 28229 28230 -- Macro: __builtin_saveregs () 28231 Use this built-in function to save the argument registers in 28232 memory so that the varargs mechanism can access them. Both ISO 28233 and traditional versions of `va_start' must use 28234 `__builtin_saveregs', unless you use 28235 `TARGET_SETUP_INCOMING_VARARGS' (see below) instead. 28236 28237 On some machines, `__builtin_saveregs' is open-coded under the 28238 control of the target hook `TARGET_EXPAND_BUILTIN_SAVEREGS'. On 28239 other machines, it calls a routine written in assembler language, 28240 found in `libgcc2.c'. 28241 28242 Code generated for the call to `__builtin_saveregs' appears at the 28243 beginning of the function, as opposed to where the call to 28244 `__builtin_saveregs' is written, regardless of what the code is. 28245 This is because the registers must be saved before the function 28246 starts to use them for its own purposes. 28247 28248 -- Macro: __builtin_args_info (CATEGORY) 28249 Use this built-in function to find the first anonymous arguments in 28250 registers. 28251 28252 In general, a machine may have several categories of registers 28253 used for arguments, each for a particular category of data types. 28254 (For example, on some machines, floating-point registers are used 28255 for floating-point arguments while other arguments are passed in 28256 the general registers.) To make non-varargs functions use the 28257 proper calling convention, you have defined the `CUMULATIVE_ARGS' 28258 data type to record how many registers in each category have been 28259 used so far 28260 28261 `__builtin_args_info' accesses the same data structure of type 28262 `CUMULATIVE_ARGS' after the ordinary argument layout is finished 28263 with it, with CATEGORY specifying which word to access. Thus, the 28264 value indicates the first unused register in a given category. 28265 28266 Normally, you would use `__builtin_args_info' in the implementation 28267 of `va_start', accessing each category just once and storing the 28268 value in the `va_list' object. This is because `va_list' will 28269 have to update the values, and there is no way to alter the values 28270 accessed by `__builtin_args_info'. 28271 28272 -- Macro: __builtin_next_arg (LASTARG) 28273 This is the equivalent of `__builtin_args_info', for stack 28274 arguments. It returns the address of the first anonymous stack 28275 argument, as type `void *'. If `ARGS_GROW_DOWNWARD', it returns 28276 the address of the location above the first anonymous stack 28277 argument. Use it in `va_start' to initialize the pointer for 28278 fetching arguments from the stack. Also use it in `va_start' to 28279 verify that the second parameter LASTARG is the last named argument 28280 of the current function. 28281 28282 -- Macro: __builtin_classify_type (OBJECT) 28283 Since each machine has its own conventions for which data types are 28284 passed in which kind of register, your implementation of `va_arg' 28285 has to embody these conventions. The easiest way to categorize the 28286 specified data type is to use `__builtin_classify_type' together 28287 with `sizeof' and `__alignof__'. 28288 28289 `__builtin_classify_type' ignores the value of OBJECT, considering 28290 only its data type. It returns an integer describing what kind of 28291 type that is--integer, floating, pointer, structure, and so on. 28292 28293 The file `typeclass.h' defines an enumeration that you can use to 28294 interpret the values of `__builtin_classify_type'. 28295 28296 These machine description macros help implement varargs: 28297 28298 -- Target Hook: rtx TARGET_EXPAND_BUILTIN_SAVEREGS (void) 28299 If defined, this hook produces the machine-specific code for a 28300 call to `__builtin_saveregs'. This code will be moved to the very 28301 beginning of the function, before any parameter access are made. 28302 The return value of this function should be an RTX that contains 28303 the value to use as the return of `__builtin_saveregs'. 28304 28305 -- Target Hook: void TARGET_SETUP_INCOMING_VARARGS (CUMULATIVE_ARGS 28306 *ARGS_SO_FAR, enum machine_mode MODE, tree TYPE, int 28307 *PRETEND_ARGS_SIZE, int SECOND_TIME) 28308 This target hook offers an alternative to using 28309 `__builtin_saveregs' and defining the hook 28310 `TARGET_EXPAND_BUILTIN_SAVEREGS'. Use it to store the anonymous 28311 register arguments into the stack so that all the arguments appear 28312 to have been passed consecutively on the stack. Once this is 28313 done, you can use the standard implementation of varargs that 28314 works for machines that pass all their arguments on the stack. 28315 28316 The argument ARGS_SO_FAR points to the `CUMULATIVE_ARGS' data 28317 structure, containing the values that are obtained after 28318 processing the named arguments. The arguments MODE and TYPE 28319 describe the last named argument--its machine mode and its data 28320 type as a tree node. 28321 28322 The target hook should do two things: first, push onto the stack 28323 all the argument registers _not_ used for the named arguments, and 28324 second, store the size of the data thus pushed into the 28325 `int'-valued variable pointed to by PRETEND_ARGS_SIZE. The value 28326 that you store here will serve as additional offset for setting up 28327 the stack frame. 28328 28329 Because you must generate code to push the anonymous arguments at 28330 compile time without knowing their data types, 28331 `TARGET_SETUP_INCOMING_VARARGS' is only useful on machines that 28332 have just a single category of argument register and use it 28333 uniformly for all data types. 28334 28335 If the argument SECOND_TIME is nonzero, it means that the 28336 arguments of the function are being analyzed for the second time. 28337 This happens for an inline function, which is not actually 28338 compiled until the end of the source file. The hook 28339 `TARGET_SETUP_INCOMING_VARARGS' should not generate any 28340 instructions in this case. 28341 28342 -- Target Hook: bool TARGET_STRICT_ARGUMENT_NAMING (CUMULATIVE_ARGS 28343 *CA) 28344 Define this hook to return `true' if the location where a function 28345 argument is passed depends on whether or not it is a named 28346 argument. 28347 28348 This hook controls how the NAMED argument to `FUNCTION_ARG' is set 28349 for varargs and stdarg functions. If this hook returns `true', 28350 the NAMED argument is always true for named arguments, and false 28351 for unnamed arguments. If it returns `false', but 28352 `TARGET_PRETEND_OUTGOING_VARARGS_NAMED' returns `true', then all 28353 arguments are treated as named. Otherwise, all named arguments 28354 except the last are treated as named. 28355 28356 You need not define this hook if it always returns zero. 28357 28358 -- Target Hook: bool TARGET_PRETEND_OUTGOING_VARARGS_NAMED 28359 If you need to conditionally change ABIs so that one works with 28360 `TARGET_SETUP_INCOMING_VARARGS', but the other works like neither 28361 `TARGET_SETUP_INCOMING_VARARGS' nor 28362 `TARGET_STRICT_ARGUMENT_NAMING' was defined, then define this hook 28363 to return `true' if `TARGET_SETUP_INCOMING_VARARGS' is used, 28364 `false' otherwise. Otherwise, you should not define this hook. 28365 28366 28367 File: gccint.info, Node: Trampolines, Next: Library Calls, Prev: Varargs, Up: Target Macros 28368 28369 17.12 Trampolines for Nested Functions 28370 ====================================== 28371 28372 A "trampoline" is a small piece of code that is created at run time 28373 when the address of a nested function is taken. It normally resides on 28374 the stack, in the stack frame of the containing function. These macros 28375 tell GCC how to generate code to allocate and initialize a trampoline. 28376 28377 The instructions in the trampoline must do two things: load a constant 28378 address into the static chain register, and jump to the real address of 28379 the nested function. On CISC machines such as the m68k, this requires 28380 two instructions, a move immediate and a jump. Then the two addresses 28381 exist in the trampoline as word-long immediate operands. On RISC 28382 machines, it is often necessary to load each address into a register in 28383 two parts. Then pieces of each address form separate immediate 28384 operands. 28385 28386 The code generated to initialize the trampoline must store the variable 28387 parts--the static chain value and the function address--into the 28388 immediate operands of the instructions. On a CISC machine, this is 28389 simply a matter of copying each address to a memory reference at the 28390 proper offset from the start of the trampoline. On a RISC machine, it 28391 may be necessary to take out pieces of the address and store them 28392 separately. 28393 28394 -- Macro: TRAMPOLINE_TEMPLATE (FILE) 28395 A C statement to output, on the stream FILE, assembler code for a 28396 block of data that contains the constant parts of a trampoline. 28397 This code should not include a label--the label is taken care of 28398 automatically. 28399 28400 If you do not define this macro, it means no template is needed 28401 for the target. Do not define this macro on systems where the 28402 block move code to copy the trampoline into place would be larger 28403 than the code to generate it on the spot. 28404 28405 -- Macro: TRAMPOLINE_SECTION 28406 Return the section into which the trampoline template is to be 28407 placed (*note Sections::). The default value is 28408 `readonly_data_section'. 28409 28410 -- Macro: TRAMPOLINE_SIZE 28411 A C expression for the size in bytes of the trampoline, as an 28412 integer. 28413 28414 -- Macro: TRAMPOLINE_ALIGNMENT 28415 Alignment required for trampolines, in bits. 28416 28417 If you don't define this macro, the value of `BIGGEST_ALIGNMENT' 28418 is used for aligning trampolines. 28419 28420 -- Macro: INITIALIZE_TRAMPOLINE (ADDR, FNADDR, STATIC_CHAIN) 28421 A C statement to initialize the variable parts of a trampoline. 28422 ADDR is an RTX for the address of the trampoline; FNADDR is an RTX 28423 for the address of the nested function; STATIC_CHAIN is an RTX for 28424 the static chain value that should be passed to the function when 28425 it is called. 28426 28427 -- Macro: TRAMPOLINE_ADJUST_ADDRESS (ADDR) 28428 A C statement that should perform any machine-specific adjustment 28429 in the address of the trampoline. Its argument contains the 28430 address that was passed to `INITIALIZE_TRAMPOLINE'. In case the 28431 address to be used for a function call should be different from 28432 the address in which the template was stored, the different 28433 address should be assigned to ADDR. If this macro is not defined, 28434 ADDR will be used for function calls. 28435 28436 If this macro is not defined, by default the trampoline is 28437 allocated as a stack slot. This default is right for most 28438 machines. The exceptions are machines where it is impossible to 28439 execute instructions in the stack area. On such machines, you may 28440 have to implement a separate stack, using this macro in 28441 conjunction with `TARGET_ASM_FUNCTION_PROLOGUE' and 28442 `TARGET_ASM_FUNCTION_EPILOGUE'. 28443 28444 FP points to a data structure, a `struct function', which 28445 describes the compilation status of the immediate containing 28446 function of the function which the trampoline is for. The stack 28447 slot for the trampoline is in the stack frame of this containing 28448 function. Other allocation strategies probably must do something 28449 analogous with this information. 28450 28451 Implementing trampolines is difficult on many machines because they 28452 have separate instruction and data caches. Writing into a stack 28453 location fails to clear the memory in the instruction cache, so when 28454 the program jumps to that location, it executes the old contents. 28455 28456 Here are two possible solutions. One is to clear the relevant parts of 28457 the instruction cache whenever a trampoline is set up. The other is to 28458 make all trampolines identical, by having them jump to a standard 28459 subroutine. The former technique makes trampoline execution faster; the 28460 latter makes initialization faster. 28461 28462 To clear the instruction cache when a trampoline is initialized, define 28463 the following macro. 28464 28465 -- Macro: CLEAR_INSN_CACHE (BEG, END) 28466 If defined, expands to a C expression clearing the _instruction 28467 cache_ in the specified interval. The definition of this macro 28468 would typically be a series of `asm' statements. Both BEG and END 28469 are both pointer expressions. 28470 28471 The operating system may also require the stack to be made executable 28472 before calling the trampoline. To implement this requirement, define 28473 the following macro. 28474 28475 -- Macro: ENABLE_EXECUTE_STACK 28476 Define this macro if certain operations must be performed before 28477 executing code located on the stack. The macro should expand to a 28478 series of C file-scope constructs (e.g. functions) and provide a 28479 unique entry point named `__enable_execute_stack'. The target is 28480 responsible for emitting calls to the entry point in the code, for 28481 example from the `INITIALIZE_TRAMPOLINE' macro. 28482 28483 To use a standard subroutine, define the following macro. In addition, 28484 you must make sure that the instructions in a trampoline fill an entire 28485 cache line with identical instructions, or else ensure that the 28486 beginning of the trampoline code is always aligned at the same point in 28487 its cache line. Look in `m68k.h' as a guide. 28488 28489 -- Macro: TRANSFER_FROM_TRAMPOLINE 28490 Define this macro if trampolines need a special subroutine to do 28491 their work. The macro should expand to a series of `asm' 28492 statements which will be compiled with GCC. They go in a library 28493 function named `__transfer_from_trampoline'. 28494 28495 If you need to avoid executing the ordinary prologue code of a 28496 compiled C function when you jump to the subroutine, you can do so 28497 by placing a special label of your own in the assembler code. Use 28498 one `asm' statement to generate an assembler label, and another to 28499 make the label global. Then trampolines can use that label to 28500 jump directly to your special assembler code. 28501 28502 28503 File: gccint.info, Node: Library Calls, Next: Addressing Modes, Prev: Trampolines, Up: Target Macros 28504 28505 17.13 Implicit Calls to Library Routines 28506 ======================================== 28507 28508 Here is an explanation of implicit calls to library routines. 28509 28510 -- Macro: DECLARE_LIBRARY_RENAMES 28511 This macro, if defined, should expand to a piece of C code that 28512 will get expanded when compiling functions for libgcc.a. It can 28513 be used to provide alternate names for GCC's internal library 28514 functions if there are ABI-mandated names that the compiler should 28515 provide. 28516 28517 -- Target Hook: void TARGET_INIT_LIBFUNCS (void) 28518 This hook should declare additional library routines or rename 28519 existing ones, using the functions `set_optab_libfunc' and 28520 `init_one_libfunc' defined in `optabs.c'. `init_optabs' calls 28521 this macro after initializing all the normal library routines. 28522 28523 The default is to do nothing. Most ports don't need to define 28524 this hook. 28525 28526 -- Macro: FLOAT_LIB_COMPARE_RETURNS_BOOL (MODE, COMPARISON) 28527 This macro should return `true' if the library routine that 28528 implements the floating point comparison operator COMPARISON in 28529 mode MODE will return a boolean, and FALSE if it will return a 28530 tristate. 28531 28532 GCC's own floating point libraries return tristates from the 28533 comparison operators, so the default returns false always. Most 28534 ports don't need to define this macro. 28535 28536 -- Macro: TARGET_LIB_INT_CMP_BIASED 28537 This macro should evaluate to `true' if the integer comparison 28538 functions (like `__cmpdi2') return 0 to indicate that the first 28539 operand is smaller than the second, 1 to indicate that they are 28540 equal, and 2 to indicate that the first operand is greater than 28541 the second. If this macro evaluates to `false' the comparison 28542 functions return -1, 0, and 1 instead of 0, 1, and 2. If the 28543 target uses the routines in `libgcc.a', you do not need to define 28544 this macro. 28545 28546 -- Macro: US_SOFTWARE_GOFAST 28547 Define this macro if your system C library uses the US Software 28548 GOFAST library to provide floating point emulation. 28549 28550 In addition to defining this macro, your architecture must set 28551 `TARGET_INIT_LIBFUNCS' to `gofast_maybe_init_libfuncs', or else 28552 call that function from its version of that hook. It is defined 28553 in `config/gofast.h', which must be included by your 28554 architecture's `CPU.c' file. See `sparc/sparc.c' for an example. 28555 28556 If this macro is defined, the 28557 `TARGET_FLOAT_LIB_COMPARE_RETURNS_BOOL' target hook must return 28558 false for `SFmode' and `DFmode' comparisons. 28559 28560 -- Macro: TARGET_EDOM 28561 The value of `EDOM' on the target machine, as a C integer constant 28562 expression. If you don't define this macro, GCC does not attempt 28563 to deposit the value of `EDOM' into `errno' directly. Look in 28564 `/usr/include/errno.h' to find the value of `EDOM' on your system. 28565 28566 If you do not define `TARGET_EDOM', then compiled code reports 28567 domain errors by calling the library function and letting it 28568 report the error. If mathematical functions on your system use 28569 `matherr' when there is an error, then you should leave 28570 `TARGET_EDOM' undefined so that `matherr' is used normally. 28571 28572 -- Macro: GEN_ERRNO_RTX 28573 Define this macro as a C expression to create an rtl expression 28574 that refers to the global "variable" `errno'. (On certain systems, 28575 `errno' may not actually be a variable.) If you don't define this 28576 macro, a reasonable default is used. 28577 28578 -- Macro: TARGET_C99_FUNCTIONS 28579 When this macro is nonzero, GCC will implicitly optimize `sin' 28580 calls into `sinf' and similarly for other functions defined by C99 28581 standard. The default is zero because a number of existing 28582 systems lack support for these functions in their runtime so this 28583 macro needs to be redefined to one on systems that do support the 28584 C99 runtime. 28585 28586 -- Macro: TARGET_HAS_SINCOS 28587 When this macro is nonzero, GCC will implicitly optimize calls to 28588 `sin' and `cos' with the same argument to a call to `sincos'. The 28589 default is zero. The target has to provide the following 28590 functions: 28591 void sincos(double x, double *sin, double *cos); 28592 void sincosf(float x, float *sin, float *cos); 28593 void sincosl(long double x, long double *sin, long double *cos); 28594 28595 -- Macro: NEXT_OBJC_RUNTIME 28596 Define this macro to generate code for Objective-C message sending 28597 using the calling convention of the NeXT system. This calling 28598 convention involves passing the object, the selector and the 28599 method arguments all at once to the method-lookup library function. 28600 28601 The default calling convention passes just the object and the 28602 selector to the lookup function, which returns a pointer to the 28603 method. 28604 28605 28606 File: gccint.info, Node: Addressing Modes, Next: Anchored Addresses, Prev: Library Calls, Up: Target Macros 28607 28608 17.14 Addressing Modes 28609 ====================== 28610 28611 This is about addressing modes. 28612 28613 -- Macro: HAVE_PRE_INCREMENT 28614 -- Macro: HAVE_PRE_DECREMENT 28615 -- Macro: HAVE_POST_INCREMENT 28616 -- Macro: HAVE_POST_DECREMENT 28617 A C expression that is nonzero if the machine supports 28618 pre-increment, pre-decrement, post-increment, or post-decrement 28619 addressing respectively. 28620 28621 -- Macro: HAVE_PRE_MODIFY_DISP 28622 -- Macro: HAVE_POST_MODIFY_DISP 28623 A C expression that is nonzero if the machine supports pre- or 28624 post-address side-effect generation involving constants other than 28625 the size of the memory operand. 28626 28627 -- Macro: HAVE_PRE_MODIFY_REG 28628 -- Macro: HAVE_POST_MODIFY_REG 28629 A C expression that is nonzero if the machine supports pre- or 28630 post-address side-effect generation involving a register 28631 displacement. 28632 28633 -- Macro: CONSTANT_ADDRESS_P (X) 28634 A C expression that is 1 if the RTX X is a constant which is a 28635 valid address. On most machines, this can be defined as 28636 `CONSTANT_P (X)', but a few machines are more restrictive in which 28637 constant addresses are supported. 28638 28639 -- Macro: CONSTANT_P (X) 28640 `CONSTANT_P', which is defined by target-independent code, accepts 28641 integer-values expressions whose values are not explicitly known, 28642 such as `symbol_ref', `label_ref', and `high' expressions and 28643 `const' arithmetic expressions, in addition to `const_int' and 28644 `const_double' expressions. 28645 28646 -- Macro: MAX_REGS_PER_ADDRESS 28647 A number, the maximum number of registers that can appear in a 28648 valid memory address. Note that it is up to you to specify a 28649 value equal to the maximum number that `GO_IF_LEGITIMATE_ADDRESS' 28650 would ever accept. 28651 28652 -- Macro: GO_IF_LEGITIMATE_ADDRESS (MODE, X, LABEL) 28653 A C compound statement with a conditional `goto LABEL;' executed 28654 if X (an RTX) is a legitimate memory address on the target machine 28655 for a memory operand of mode MODE. 28656 28657 It usually pays to define several simpler macros to serve as 28658 subroutines for this one. Otherwise it may be too complicated to 28659 understand. 28660 28661 This macro must exist in two variants: a strict variant and a 28662 non-strict one. The strict variant is used in the reload pass. It 28663 must be defined so that any pseudo-register that has not been 28664 allocated a hard register is considered a memory reference. In 28665 contexts where some kind of register is required, a pseudo-register 28666 with no hard register must be rejected. 28667 28668 The non-strict variant is used in other passes. It must be 28669 defined to accept all pseudo-registers in every context where some 28670 kind of register is required. 28671 28672 Compiler source files that want to use the strict variant of this 28673 macro define the macro `REG_OK_STRICT'. You should use an `#ifdef 28674 REG_OK_STRICT' conditional to define the strict variant in that 28675 case and the non-strict variant otherwise. 28676 28677 Subroutines to check for acceptable registers for various purposes 28678 (one for base registers, one for index registers, and so on) are 28679 typically among the subroutines used to define 28680 `GO_IF_LEGITIMATE_ADDRESS'. Then only these subroutine macros 28681 need have two variants; the higher levels of macros may be the 28682 same whether strict or not. 28683 28684 Normally, constant addresses which are the sum of a `symbol_ref' 28685 and an integer are stored inside a `const' RTX to mark them as 28686 constant. Therefore, there is no need to recognize such sums 28687 specifically as legitimate addresses. Normally you would simply 28688 recognize any `const' as legitimate. 28689 28690 Usually `PRINT_OPERAND_ADDRESS' is not prepared to handle constant 28691 sums that are not marked with `const'. It assumes that a naked 28692 `plus' indicates indexing. If so, then you _must_ reject such 28693 naked constant sums as illegitimate addresses, so that none of 28694 them will be given to `PRINT_OPERAND_ADDRESS'. 28695 28696 On some machines, whether a symbolic address is legitimate depends 28697 on the section that the address refers to. On these machines, 28698 define the target hook `TARGET_ENCODE_SECTION_INFO' to store the 28699 information into the `symbol_ref', and then check for it here. 28700 When you see a `const', you will have to look inside it to find the 28701 `symbol_ref' in order to determine the section. *Note Assembler 28702 Format::. 28703 28704 -- Macro: TARGET_MEM_CONSTRAINT 28705 A single character to be used instead of the default `'m'' 28706 character for general memory addresses. This defines the 28707 constraint letter which matches the memory addresses accepted by 28708 `GO_IF_LEGITIMATE_ADDRESS_P'. Define this macro if you want to 28709 support new address formats in your back end without changing the 28710 semantics of the `'m'' constraint. This is necessary in order to 28711 preserve functionality of inline assembly constructs using the 28712 `'m'' constraint. 28713 28714 -- Macro: FIND_BASE_TERM (X) 28715 A C expression to determine the base term of address X, or to 28716 provide a simplified version of X from which `alias.c' can easily 28717 find the base term. This macro is used in only two places: 28718 `find_base_value' and `find_base_term' in `alias.c'. 28719 28720 It is always safe for this macro to not be defined. It exists so 28721 that alias analysis can understand machine-dependent addresses. 28722 28723 The typical use of this macro is to handle addresses containing a 28724 label_ref or symbol_ref within an UNSPEC. 28725 28726 -- Macro: LEGITIMIZE_ADDRESS (X, OLDX, MODE, WIN) 28727 A C compound statement that attempts to replace X with a valid 28728 memory address for an operand of mode MODE. WIN will be a C 28729 statement label elsewhere in the code; the macro definition may use 28730 28731 GO_IF_LEGITIMATE_ADDRESS (MODE, X, WIN); 28732 28733 to avoid further processing if the address has become legitimate. 28734 28735 X will always be the result of a call to `break_out_memory_refs', 28736 and OLDX will be the operand that was given to that function to 28737 produce X. 28738 28739 The code generated by this macro should not alter the substructure 28740 of X. If it transforms X into a more legitimate form, it should 28741 assign X (which will always be a C variable) a new value. 28742 28743 It is not necessary for this macro to come up with a legitimate 28744 address. The compiler has standard ways of doing so in all cases. 28745 In fact, it is safe to omit this macro. But often a 28746 machine-dependent strategy can generate better code. 28747 28748 -- Macro: LEGITIMIZE_RELOAD_ADDRESS (X, MODE, OPNUM, TYPE, IND_LEVELS, 28749 WIN) 28750 A C compound statement that attempts to replace X, which is an 28751 address that needs reloading, with a valid memory address for an 28752 operand of mode MODE. WIN will be a C statement label elsewhere 28753 in the code. It is not necessary to define this macro, but it 28754 might be useful for performance reasons. 28755 28756 For example, on the i386, it is sometimes possible to use a single 28757 reload register instead of two by reloading a sum of two pseudo 28758 registers into a register. On the other hand, for number of RISC 28759 processors offsets are limited so that often an intermediate 28760 address needs to be generated in order to address a stack slot. 28761 By defining `LEGITIMIZE_RELOAD_ADDRESS' appropriately, the 28762 intermediate addresses generated for adjacent some stack slots can 28763 be made identical, and thus be shared. 28764 28765 _Note_: This macro should be used with caution. It is necessary 28766 to know something of how reload works in order to effectively use 28767 this, and it is quite easy to produce macros that build in too 28768 much knowledge of reload internals. 28769 28770 _Note_: This macro must be able to reload an address created by a 28771 previous invocation of this macro. If it fails to handle such 28772 addresses then the compiler may generate incorrect code or abort. 28773 28774 The macro definition should use `push_reload' to indicate parts 28775 that need reloading; OPNUM, TYPE and IND_LEVELS are usually 28776 suitable to be passed unaltered to `push_reload'. 28777 28778 The code generated by this macro must not alter the substructure of 28779 X. If it transforms X into a more legitimate form, it should 28780 assign X (which will always be a C variable) a new value. This 28781 also applies to parts that you change indirectly by calling 28782 `push_reload'. 28783 28784 The macro definition may use `strict_memory_address_p' to test if 28785 the address has become legitimate. 28786 28787 If you want to change only a part of X, one standard way of doing 28788 this is to use `copy_rtx'. Note, however, that it unshares only a 28789 single level of rtl. Thus, if the part to be changed is not at the 28790 top level, you'll need to replace first the top level. It is not 28791 necessary for this macro to come up with a legitimate address; 28792 but often a machine-dependent strategy can generate better code. 28793 28794 -- Macro: GO_IF_MODE_DEPENDENT_ADDRESS (ADDR, LABEL) 28795 A C statement or compound statement with a conditional `goto 28796 LABEL;' executed if memory address X (an RTX) can have different 28797 meanings depending on the machine mode of the memory reference it 28798 is used for or if the address is valid for some modes but not 28799 others. 28800 28801 Autoincrement and autodecrement addresses typically have 28802 mode-dependent effects because the amount of the increment or 28803 decrement is the size of the operand being addressed. Some 28804 machines have other mode-dependent addresses. Many RISC machines 28805 have no mode-dependent addresses. 28806 28807 You may assume that ADDR is a valid address for the machine. 28808 28809 -- Macro: LEGITIMATE_CONSTANT_P (X) 28810 A C expression that is nonzero if X is a legitimate constant for 28811 an immediate operand on the target machine. You can assume that X 28812 satisfies `CONSTANT_P', so you need not check this. In fact, `1' 28813 is a suitable definition for this macro on machines where anything 28814 `CONSTANT_P' is valid. 28815 28816 -- Target Hook: rtx TARGET_DELEGITIMIZE_ADDRESS (rtx X) 28817 This hook is used to undo the possibly obfuscating effects of the 28818 `LEGITIMIZE_ADDRESS' and `LEGITIMIZE_RELOAD_ADDRESS' target 28819 macros. Some backend implementations of these macros wrap symbol 28820 references inside an `UNSPEC' rtx to represent PIC or similar 28821 addressing modes. This target hook allows GCC's optimizers to 28822 understand the semantics of these opaque `UNSPEC's by converting 28823 them back into their original form. 28824 28825 -- Target Hook: bool TARGET_CANNOT_FORCE_CONST_MEM (rtx X) 28826 This hook should return true if X is of a form that cannot (or 28827 should not) be spilled to the constant pool. The default version 28828 of this hook returns false. 28829 28830 The primary reason to define this hook is to prevent reload from 28831 deciding that a non-legitimate constant would be better reloaded 28832 from the constant pool instead of spilling and reloading a register 28833 holding the constant. This restriction is often true of addresses 28834 of TLS symbols for various targets. 28835 28836 -- Target Hook: bool TARGET_USE_BLOCKS_FOR_CONSTANT_P (enum 28837 machine_mode MODE, rtx X) 28838 This hook should return true if pool entries for constant X can be 28839 placed in an `object_block' structure. MODE is the mode of X. 28840 28841 The default version returns false for all constants. 28842 28843 -- Target Hook: tree TARGET_BUILTIN_RECIPROCAL (enum tree_code FN, 28844 bool TM_FN, bool SQRT) 28845 This hook should return the DECL of a function that implements 28846 reciprocal of the builtin function with builtin function code FN, 28847 or `NULL_TREE' if such a function is not available. TM_FN is true 28848 when FN is a code of a machine-dependent builtin function. When 28849 SQRT is true, additional optimizations that apply only to the 28850 reciprocal of a square root function are performed, and only 28851 reciprocals of `sqrt' function are valid. 28852 28853 -- Target Hook: tree TARGET_VECTORIZE_BUILTIN_MASK_FOR_LOAD (void) 28854 This hook should return the DECL of a function F that given an 28855 address ADDR as an argument returns a mask M that can be used to 28856 extract from two vectors the relevant data that resides in ADDR in 28857 case ADDR is not properly aligned. 28858 28859 The autovectorizer, when vectorizing a load operation from an 28860 address ADDR that may be unaligned, will generate two vector loads 28861 from the two aligned addresses around ADDR. It then generates a 28862 `REALIGN_LOAD' operation to extract the relevant data from the two 28863 loaded vectors. The first two arguments to `REALIGN_LOAD', V1 and 28864 V2, are the two vectors, each of size VS, and the third argument, 28865 OFF, defines how the data will be extracted from these two 28866 vectors: if OFF is 0, then the returned vector is V2; otherwise, 28867 the returned vector is composed from the last VS-OFF elements of 28868 V1 concatenated to the first OFF elements of V2. 28869 28870 If this hook is defined, the autovectorizer will generate a call 28871 to F (using the DECL tree that this hook returns) and will use the 28872 return value of F as the argument OFF to `REALIGN_LOAD'. 28873 Therefore, the mask M returned by F should comply with the 28874 semantics expected by `REALIGN_LOAD' described above. If this 28875 hook is not defined, then ADDR will be used as the argument OFF to 28876 `REALIGN_LOAD', in which case the low log2(VS)-1 bits of ADDR will 28877 be considered. 28878 28879 -- Target Hook: tree TARGET_VECTORIZE_BUILTIN_MUL_WIDEN_EVEN (tree X) 28880 This hook should return the DECL of a function F that implements 28881 widening multiplication of the even elements of two input vectors 28882 of type X. 28883 28884 If this hook is defined, the autovectorizer will use it along with 28885 the `TARGET_VECTORIZE_BUILTIN_MUL_WIDEN_ODD' target hook when 28886 vectorizing widening multiplication in cases that the order of the 28887 results does not have to be preserved (e.g. used only by a 28888 reduction computation). Otherwise, the `widen_mult_hi/lo' idioms 28889 will be used. 28890 28891 -- Target Hook: tree TARGET_VECTORIZE_BUILTIN_MUL_WIDEN_ODD (tree X) 28892 This hook should return the DECL of a function F that implements 28893 widening multiplication of the odd elements of two input vectors 28894 of type X. 28895 28896 If this hook is defined, the autovectorizer will use it along with 28897 the `TARGET_VECTORIZE_BUILTIN_MUL_WIDEN_EVEN' target hook when 28898 vectorizing widening multiplication in cases that the order of the 28899 results does not have to be preserved (e.g. used only by a 28900 reduction computation). Otherwise, the `widen_mult_hi/lo' idioms 28901 will be used. 28902 28903 -- Target Hook: tree TARGET_VECTORIZE_BUILTIN_CONVERSION (enum 28904 tree_code CODE, tree TYPE) 28905 This hook should return the DECL of a function that implements 28906 conversion of the input vector of type TYPE. If TYPE is an 28907 integral type, the result of the conversion is a vector of 28908 floating-point type of the same size. If TYPE is a floating-point 28909 type, the result of the conversion is a vector of integral type of 28910 the same size. CODE specifies how the conversion is to be applied 28911 (truncation, rounding, etc.). 28912 28913 If this hook is defined, the autovectorizer will use the 28914 `TARGET_VECTORIZE_BUILTIN_CONVERSION' target hook when vectorizing 28915 conversion. Otherwise, it will return `NULL_TREE'. 28916 28917 -- Target Hook: tree TARGET_VECTORIZE_BUILTIN_VECTORIZED_FUNCTION 28918 (enum built_in_function CODE, tree VEC_TYPE_OUT, tree 28919 VEC_TYPE_IN) 28920 This hook should return the decl of a function that implements the 28921 vectorized variant of the builtin function with builtin function 28922 code CODE or `NULL_TREE' if such a function is not available. The 28923 return type of the vectorized function shall be of vector type 28924 VEC_TYPE_OUT and the argument types should be VEC_TYPE_IN. 28925 28926 28927 File: gccint.info, Node: Anchored Addresses, Next: Condition Code, Prev: Addressing Modes, Up: Target Macros 28928 28929 17.15 Anchored Addresses 28930 ======================== 28931 28932 GCC usually addresses every static object as a separate entity. For 28933 example, if we have: 28934 28935 static int a, b, c; 28936 int foo (void) { return a + b + c; } 28937 28938 the code for `foo' will usually calculate three separate symbolic 28939 addresses: those of `a', `b' and `c'. On some targets, it would be 28940 better to calculate just one symbolic address and access the three 28941 variables relative to it. The equivalent pseudocode would be something 28942 like: 28943 28944 int foo (void) 28945 { 28946 register int *xr = &x; 28947 return xr[&a - &x] + xr[&b - &x] + xr[&c - &x]; 28948 } 28949 28950 (which isn't valid C). We refer to shared addresses like `x' as 28951 "section anchors". Their use is controlled by `-fsection-anchors'. 28952 28953 The hooks below describe the target properties that GCC needs to know 28954 in order to make effective use of section anchors. It won't use 28955 section anchors at all unless either `TARGET_MIN_ANCHOR_OFFSET' or 28956 `TARGET_MAX_ANCHOR_OFFSET' is set to a nonzero value. 28957 28958 -- Variable: Target Hook HOST_WIDE_INT TARGET_MIN_ANCHOR_OFFSET 28959 The minimum offset that should be applied to a section anchor. On 28960 most targets, it should be the smallest offset that can be applied 28961 to a base register while still giving a legitimate address for 28962 every mode. The default value is 0. 28963 28964 -- Variable: Target Hook HOST_WIDE_INT TARGET_MAX_ANCHOR_OFFSET 28965 Like `TARGET_MIN_ANCHOR_OFFSET', but the maximum (inclusive) 28966 offset that should be applied to section anchors. The default 28967 value is 0. 28968 28969 -- Target Hook: void TARGET_ASM_OUTPUT_ANCHOR (rtx X) 28970 Write the assembly code to define section anchor X, which is a 28971 `SYMBOL_REF' for which `SYMBOL_REF_ANCHOR_P (X)' is true. The 28972 hook is called with the assembly output position set to the 28973 beginning of `SYMBOL_REF_BLOCK (X)'. 28974 28975 If `ASM_OUTPUT_DEF' is available, the hook's default definition 28976 uses it to define the symbol as `. + SYMBOL_REF_BLOCK_OFFSET (X)'. 28977 If `ASM_OUTPUT_DEF' is not available, the hook's default definition 28978 is `NULL', which disables the use of section anchors altogether. 28979 28980 -- Target Hook: bool TARGET_USE_ANCHORS_FOR_SYMBOL_P (rtx X) 28981 Return true if GCC should attempt to use anchors to access 28982 `SYMBOL_REF' X. You can assume `SYMBOL_REF_HAS_BLOCK_INFO_P (X)' 28983 and `!SYMBOL_REF_ANCHOR_P (X)'. 28984 28985 The default version is correct for most targets, but you might 28986 need to intercept this hook to handle things like target-specific 28987 attributes or target-specific sections. 28988 28989 28990 File: gccint.info, Node: Condition Code, Next: Costs, Prev: Anchored Addresses, Up: Target Macros 28991 28992 17.16 Condition Code Status 28993 =========================== 28994 28995 This describes the condition code status. 28996 28997 The file `conditions.h' defines a variable `cc_status' to describe how 28998 the condition code was computed (in case the interpretation of the 28999 condition code depends on the instruction that it was set by). This 29000 variable contains the RTL expressions on which the condition code is 29001 currently based, and several standard flags. 29002 29003 Sometimes additional machine-specific flags must be defined in the 29004 machine description header file. It can also add additional 29005 machine-specific information by defining `CC_STATUS_MDEP'. 29006 29007 -- Macro: CC_STATUS_MDEP 29008 C code for a data type which is used for declaring the `mdep' 29009 component of `cc_status'. It defaults to `int'. 29010 29011 This macro is not used on machines that do not use `cc0'. 29012 29013 -- Macro: CC_STATUS_MDEP_INIT 29014 A C expression to initialize the `mdep' field to "empty". The 29015 default definition does nothing, since most machines don't use the 29016 field anyway. If you want to use the field, you should probably 29017 define this macro to initialize it. 29018 29019 This macro is not used on machines that do not use `cc0'. 29020 29021 -- Macro: NOTICE_UPDATE_CC (EXP, INSN) 29022 A C compound statement to set the components of `cc_status' 29023 appropriately for an insn INSN whose body is EXP. It is this 29024 macro's responsibility to recognize insns that set the condition 29025 code as a byproduct of other activity as well as those that 29026 explicitly set `(cc0)'. 29027 29028 This macro is not used on machines that do not use `cc0'. 29029 29030 If there are insns that do not set the condition code but do alter 29031 other machine registers, this macro must check to see whether they 29032 invalidate the expressions that the condition code is recorded as 29033 reflecting. For example, on the 68000, insns that store in address 29034 registers do not set the condition code, which means that usually 29035 `NOTICE_UPDATE_CC' can leave `cc_status' unaltered for such insns. 29036 But suppose that the previous insn set the condition code based 29037 on location `a4@(102)' and the current insn stores a new value in 29038 `a4'. Although the condition code is not changed by this, it will 29039 no longer be true that it reflects the contents of `a4@(102)'. 29040 Therefore, `NOTICE_UPDATE_CC' must alter `cc_status' in this case 29041 to say that nothing is known about the condition code value. 29042 29043 The definition of `NOTICE_UPDATE_CC' must be prepared to deal with 29044 the results of peephole optimization: insns whose patterns are 29045 `parallel' RTXs containing various `reg', `mem' or constants which 29046 are just the operands. The RTL structure of these insns is not 29047 sufficient to indicate what the insns actually do. What 29048 `NOTICE_UPDATE_CC' should do when it sees one is just to run 29049 `CC_STATUS_INIT'. 29050 29051 A possible definition of `NOTICE_UPDATE_CC' is to call a function 29052 that looks at an attribute (*note Insn Attributes::) named, for 29053 example, `cc'. This avoids having detailed information about 29054 patterns in two places, the `md' file and in `NOTICE_UPDATE_CC'. 29055 29056 -- Macro: SELECT_CC_MODE (OP, X, Y) 29057 Returns a mode from class `MODE_CC' to be used when comparison 29058 operation code OP is applied to rtx X and Y. For example, on the 29059 SPARC, `SELECT_CC_MODE' is defined as (see *note Jump Patterns:: 29060 for a description of the reason for this definition) 29061 29062 #define SELECT_CC_MODE(OP,X,Y) \ 29063 (GET_MODE_CLASS (GET_MODE (X)) == MODE_FLOAT \ 29064 ? ((OP == EQ || OP == NE) ? CCFPmode : CCFPEmode) \ 29065 : ((GET_CODE (X) == PLUS || GET_CODE (X) == MINUS \ 29066 || GET_CODE (X) == NEG) \ 29067 ? CC_NOOVmode : CCmode)) 29068 29069 You should define this macro if and only if you define extra CC 29070 modes in `MACHINE-modes.def'. 29071 29072 -- Macro: CANONICALIZE_COMPARISON (CODE, OP0, OP1) 29073 On some machines not all possible comparisons are defined, but you 29074 can convert an invalid comparison into a valid one. For example, 29075 the Alpha does not have a `GT' comparison, but you can use an `LT' 29076 comparison instead and swap the order of the operands. 29077 29078 On such machines, define this macro to be a C statement to do any 29079 required conversions. CODE is the initial comparison code and OP0 29080 and OP1 are the left and right operands of the comparison, 29081 respectively. You should modify CODE, OP0, and OP1 as required. 29082 29083 GCC will not assume that the comparison resulting from this macro 29084 is valid but will see if the resulting insn matches a pattern in 29085 the `md' file. 29086 29087 You need not define this macro if it would never change the 29088 comparison code or operands. 29089 29090 -- Macro: REVERSIBLE_CC_MODE (MODE) 29091 A C expression whose value is one if it is always safe to reverse a 29092 comparison whose mode is MODE. If `SELECT_CC_MODE' can ever 29093 return MODE for a floating-point inequality comparison, then 29094 `REVERSIBLE_CC_MODE (MODE)' must be zero. 29095 29096 You need not define this macro if it would always returns zero or 29097 if the floating-point format is anything other than 29098 `IEEE_FLOAT_FORMAT'. For example, here is the definition used on 29099 the SPARC, where floating-point inequality comparisons are always 29100 given `CCFPEmode': 29101 29102 #define REVERSIBLE_CC_MODE(MODE) ((MODE) != CCFPEmode) 29103 29104 -- Macro: REVERSE_CONDITION (CODE, MODE) 29105 A C expression whose value is reversed condition code of the CODE 29106 for comparison done in CC_MODE MODE. The macro is used only in 29107 case `REVERSIBLE_CC_MODE (MODE)' is nonzero. Define this macro in 29108 case machine has some non-standard way how to reverse certain 29109 conditionals. For instance in case all floating point conditions 29110 are non-trapping, compiler may freely convert unordered compares 29111 to ordered one. Then definition may look like: 29112 29113 #define REVERSE_CONDITION(CODE, MODE) \ 29114 ((MODE) != CCFPmode ? reverse_condition (CODE) \ 29115 : reverse_condition_maybe_unordered (CODE)) 29116 29117 -- Macro: REVERSE_CONDEXEC_PREDICATES_P (OP1, OP2) 29118 A C expression that returns true if the conditional execution 29119 predicate OP1, a comparison operation, is the inverse of OP2 and 29120 vice versa. Define this to return 0 if the target has conditional 29121 execution predicates that cannot be reversed safely. There is no 29122 need to validate that the arguments of op1 and op2 are the same, 29123 this is done separately. If no expansion is specified, this macro 29124 is defined as follows: 29125 29126 #define REVERSE_CONDEXEC_PREDICATES_P (x, y) \ 29127 (GET_CODE ((x)) == reversed_comparison_code ((y), NULL)) 29128 29129 -- Target Hook: bool TARGET_FIXED_CONDITION_CODE_REGS (unsigned int *, 29130 unsigned int *) 29131 On targets which do not use `(cc0)', and which use a hard register 29132 rather than a pseudo-register to hold condition codes, the regular 29133 CSE passes are often not able to identify cases in which the hard 29134 register is set to a common value. Use this hook to enable a 29135 small pass which optimizes such cases. This hook should return 29136 true to enable this pass, and it should set the integers to which 29137 its arguments point to the hard register numbers used for 29138 condition codes. When there is only one such register, as is true 29139 on most systems, the integer pointed to by the second argument 29140 should be set to `INVALID_REGNUM'. 29141 29142 The default version of this hook returns false. 29143 29144 -- Target Hook: enum machine_mode TARGET_CC_MODES_COMPATIBLE (enum 29145 machine_mode, enum machine_mode) 29146 On targets which use multiple condition code modes in class 29147 `MODE_CC', it is sometimes the case that a comparison can be 29148 validly done in more than one mode. On such a system, define this 29149 target hook to take two mode arguments and to return a mode in 29150 which both comparisons may be validly done. If there is no such 29151 mode, return `VOIDmode'. 29152 29153 The default version of this hook checks whether the modes are the 29154 same. If they are, it returns that mode. If they are different, 29155 it returns `VOIDmode'. 29156 29157 29158 File: gccint.info, Node: Costs, Next: Scheduling, Prev: Condition Code, Up: Target Macros 29159 29160 17.17 Describing Relative Costs of Operations 29161 ============================================= 29162 29163 These macros let you describe the relative speed of various operations 29164 on the target machine. 29165 29166 -- Macro: REGISTER_MOVE_COST (MODE, FROM, TO) 29167 A C expression for the cost of moving data of mode MODE from a 29168 register in class FROM to one in class TO. The classes are 29169 expressed using the enumeration values such as `GENERAL_REGS'. A 29170 value of 2 is the default; other values are interpreted relative to 29171 that. 29172 29173 It is not required that the cost always equal 2 when FROM is the 29174 same as TO; on some machines it is expensive to move between 29175 registers if they are not general registers. 29176 29177 If reload sees an insn consisting of a single `set' between two 29178 hard registers, and if `REGISTER_MOVE_COST' applied to their 29179 classes returns a value of 2, reload does not check to ensure that 29180 the constraints of the insn are met. Setting a cost of other than 29181 2 will allow reload to verify that the constraints are met. You 29182 should do this if the `movM' pattern's constraints do not allow 29183 such copying. 29184 29185 -- Macro: MEMORY_MOVE_COST (MODE, CLASS, IN) 29186 A C expression for the cost of moving data of mode MODE between a 29187 register of class CLASS and memory; IN is zero if the value is to 29188 be written to memory, nonzero if it is to be read in. This cost 29189 is relative to those in `REGISTER_MOVE_COST'. If moving between 29190 registers and memory is more expensive than between two registers, 29191 you should define this macro to express the relative cost. 29192 29193 If you do not define this macro, GCC uses a default cost of 4 plus 29194 the cost of copying via a secondary reload register, if one is 29195 needed. If your machine requires a secondary reload register to 29196 copy between memory and a register of CLASS but the reload 29197 mechanism is more complex than copying via an intermediate, define 29198 this macro to reflect the actual cost of the move. 29199 29200 GCC defines the function `memory_move_secondary_cost' if secondary 29201 reloads are needed. It computes the costs due to copying via a 29202 secondary register. If your machine copies from memory using a 29203 secondary register in the conventional way but the default base 29204 value of 4 is not correct for your machine, define this macro to 29205 add some other value to the result of that function. The 29206 arguments to that function are the same as to this macro. 29207 29208 -- Macro: BRANCH_COST (SPEED_P, PREDICTABLE_P) 29209 A C expression for the cost of a branch instruction. A value of 1 29210 is the default; other values are interpreted relative to that. 29211 Parameter SPEED_P is true when the branch in question should be 29212 optimized for speed. When it is false, `BRANCH_COST' should be 29213 returning value optimal for code size rather then performance 29214 considerations. PREDICTABLE_P is true for well predictable 29215 branches. On many architectures the `BRANCH_COST' can be reduced 29216 then. 29217 29218 Here are additional macros which do not specify precise relative costs, 29219 but only that certain actions are more expensive than GCC would 29220 ordinarily expect. 29221 29222 -- Macro: SLOW_BYTE_ACCESS 29223 Define this macro as a C expression which is nonzero if accessing 29224 less than a word of memory (i.e. a `char' or a `short') is no 29225 faster than accessing a word of memory, i.e., if such access 29226 require more than one instruction or if there is no difference in 29227 cost between byte and (aligned) word loads. 29228 29229 When this macro is not defined, the compiler will access a field by 29230 finding the smallest containing object; when it is defined, a 29231 fullword load will be used if alignment permits. Unless bytes 29232 accesses are faster than word accesses, using word accesses is 29233 preferable since it may eliminate subsequent memory access if 29234 subsequent accesses occur to other fields in the same word of the 29235 structure, but to different bytes. 29236 29237 -- Macro: SLOW_UNALIGNED_ACCESS (MODE, ALIGNMENT) 29238 Define this macro to be the value 1 if memory accesses described 29239 by the MODE and ALIGNMENT parameters have a cost many times greater 29240 than aligned accesses, for example if they are emulated in a trap 29241 handler. 29242 29243 When this macro is nonzero, the compiler will act as if 29244 `STRICT_ALIGNMENT' were nonzero when generating code for block 29245 moves. This can cause significantly more instructions to be 29246 produced. Therefore, do not set this macro nonzero if unaligned 29247 accesses only add a cycle or two to the time for a memory access. 29248 29249 If the value of this macro is always zero, it need not be defined. 29250 If this macro is defined, it should produce a nonzero value when 29251 `STRICT_ALIGNMENT' is nonzero. 29252 29253 -- Macro: MOVE_RATIO 29254 The threshold of number of scalar memory-to-memory move insns, 29255 _below_ which a sequence of insns should be generated instead of a 29256 string move insn or a library call. Increasing the value will 29257 always make code faster, but eventually incurs high cost in 29258 increased code size. 29259 29260 Note that on machines where the corresponding move insn is a 29261 `define_expand' that emits a sequence of insns, this macro counts 29262 the number of such sequences. 29263 29264 If you don't define this, a reasonable default is used. 29265 29266 -- Macro: MOVE_BY_PIECES_P (SIZE, ALIGNMENT) 29267 A C expression used to determine whether `move_by_pieces' will be 29268 used to copy a chunk of memory, or whether some other block move 29269 mechanism will be used. Defaults to 1 if `move_by_pieces_ninsns' 29270 returns less than `MOVE_RATIO'. 29271 29272 -- Macro: MOVE_MAX_PIECES 29273 A C expression used by `move_by_pieces' to determine the largest 29274 unit a load or store used to copy memory is. Defaults to 29275 `MOVE_MAX'. 29276 29277 -- Macro: CLEAR_RATIO 29278 The threshold of number of scalar move insns, _below_ which a 29279 sequence of insns should be generated to clear memory instead of a 29280 string clear insn or a library call. Increasing the value will 29281 always make code faster, but eventually incurs high cost in 29282 increased code size. 29283 29284 If you don't define this, a reasonable default is used. 29285 29286 -- Macro: CLEAR_BY_PIECES_P (SIZE, ALIGNMENT) 29287 A C expression used to determine whether `clear_by_pieces' will be 29288 used to clear a chunk of memory, or whether some other block clear 29289 mechanism will be used. Defaults to 1 if `move_by_pieces_ninsns' 29290 returns less than `CLEAR_RATIO'. 29291 29292 -- Macro: SET_RATIO 29293 The threshold of number of scalar move insns, _below_ which a 29294 sequence of insns should be generated to set memory to a constant 29295 value, instead of a block set insn or a library call. Increasing 29296 the value will always make code faster, but eventually incurs high 29297 cost in increased code size. 29298 29299 If you don't define this, it defaults to the value of `MOVE_RATIO'. 29300 29301 -- Macro: SET_BY_PIECES_P (SIZE, ALIGNMENT) 29302 A C expression used to determine whether `store_by_pieces' will be 29303 used to set a chunk of memory to a constant value, or whether some 29304 other mechanism will be used. Used by `__builtin_memset' when 29305 storing values other than constant zero. Defaults to 1 if 29306 `move_by_pieces_ninsns' returns less than `SET_RATIO'. 29307 29308 -- Macro: STORE_BY_PIECES_P (SIZE, ALIGNMENT) 29309 A C expression used to determine whether `store_by_pieces' will be 29310 used to set a chunk of memory to a constant string value, or 29311 whether some other mechanism will be used. Used by 29312 `__builtin_strcpy' when called with a constant source string. 29313 Defaults to 1 if `move_by_pieces_ninsns' returns less than 29314 `MOVE_RATIO'. 29315 29316 -- Macro: USE_LOAD_POST_INCREMENT (MODE) 29317 A C expression used to determine whether a load postincrement is a 29318 good thing to use for a given mode. Defaults to the value of 29319 `HAVE_POST_INCREMENT'. 29320 29321 -- Macro: USE_LOAD_POST_DECREMENT (MODE) 29322 A C expression used to determine whether a load postdecrement is a 29323 good thing to use for a given mode. Defaults to the value of 29324 `HAVE_POST_DECREMENT'. 29325 29326 -- Macro: USE_LOAD_PRE_INCREMENT (MODE) 29327 A C expression used to determine whether a load preincrement is a 29328 good thing to use for a given mode. Defaults to the value of 29329 `HAVE_PRE_INCREMENT'. 29330 29331 -- Macro: USE_LOAD_PRE_DECREMENT (MODE) 29332 A C expression used to determine whether a load predecrement is a 29333 good thing to use for a given mode. Defaults to the value of 29334 `HAVE_PRE_DECREMENT'. 29335 29336 -- Macro: USE_STORE_POST_INCREMENT (MODE) 29337 A C expression used to determine whether a store postincrement is 29338 a good thing to use for a given mode. Defaults to the value of 29339 `HAVE_POST_INCREMENT'. 29340 29341 -- Macro: USE_STORE_POST_DECREMENT (MODE) 29342 A C expression used to determine whether a store postdecrement is 29343 a good thing to use for a given mode. Defaults to the value of 29344 `HAVE_POST_DECREMENT'. 29345 29346 -- Macro: USE_STORE_PRE_INCREMENT (MODE) 29347 This macro is used to determine whether a store preincrement is a 29348 good thing to use for a given mode. Defaults to the value of 29349 `HAVE_PRE_INCREMENT'. 29350 29351 -- Macro: USE_STORE_PRE_DECREMENT (MODE) 29352 This macro is used to determine whether a store predecrement is a 29353 good thing to use for a given mode. Defaults to the value of 29354 `HAVE_PRE_DECREMENT'. 29355 29356 -- Macro: NO_FUNCTION_CSE 29357 Define this macro if it is as good or better to call a constant 29358 function address than to call an address kept in a register. 29359 29360 -- Macro: RANGE_TEST_NON_SHORT_CIRCUIT 29361 Define this macro if a non-short-circuit operation produced by 29362 `fold_range_test ()' is optimal. This macro defaults to true if 29363 `BRANCH_COST' is greater than or equal to the value 2. 29364 29365 -- Target Hook: bool TARGET_RTX_COSTS (rtx X, int CODE, int 29366 OUTER_CODE, int *TOTAL) 29367 This target hook describes the relative costs of RTL expressions. 29368 29369 The cost may depend on the precise form of the expression, which is 29370 available for examination in X, and the rtx code of the expression 29371 in which it is contained, found in OUTER_CODE. CODE is the 29372 expression code--redundant, since it can be obtained with 29373 `GET_CODE (X)'. 29374 29375 In implementing this hook, you can use the construct 29376 `COSTS_N_INSNS (N)' to specify a cost equal to N fast instructions. 29377 29378 On entry to the hook, `*TOTAL' contains a default estimate for the 29379 cost of the expression. The hook should modify this value as 29380 necessary. Traditionally, the default costs are `COSTS_N_INSNS 29381 (5)' for multiplications, `COSTS_N_INSNS (7)' for division and 29382 modulus operations, and `COSTS_N_INSNS (1)' for all other 29383 operations. 29384 29385 When optimizing for code size, i.e. when `optimize_size' is 29386 nonzero, this target hook should be used to estimate the relative 29387 size cost of an expression, again relative to `COSTS_N_INSNS'. 29388 29389 The hook returns true when all subexpressions of X have been 29390 processed, and false when `rtx_cost' should recurse. 29391 29392 -- Target Hook: int TARGET_ADDRESS_COST (rtx ADDRESS) 29393 This hook computes the cost of an addressing mode that contains 29394 ADDRESS. If not defined, the cost is computed from the ADDRESS 29395 expression and the `TARGET_RTX_COST' hook. 29396 29397 For most CISC machines, the default cost is a good approximation 29398 of the true cost of the addressing mode. However, on RISC 29399 machines, all instructions normally have the same length and 29400 execution time. Hence all addresses will have equal costs. 29401 29402 In cases where more than one form of an address is known, the form 29403 with the lowest cost will be used. If multiple forms have the 29404 same, lowest, cost, the one that is the most complex will be used. 29405 29406 For example, suppose an address that is equal to the sum of a 29407 register and a constant is used twice in the same basic block. 29408 When this macro is not defined, the address will be computed in a 29409 register and memory references will be indirect through that 29410 register. On machines where the cost of the addressing mode 29411 containing the sum is no higher than that of a simple indirect 29412 reference, this will produce an additional instruction and 29413 possibly require an additional register. Proper specification of 29414 this macro eliminates this overhead for such machines. 29415 29416 This hook is never called with an invalid address. 29417 29418 On machines where an address involving more than one register is as 29419 cheap as an address computation involving only one register, 29420 defining `TARGET_ADDRESS_COST' to reflect this can cause two 29421 registers to be live over a region of code where only one would 29422 have been if `TARGET_ADDRESS_COST' were not defined in that 29423 manner. This effect should be considered in the definition of 29424 this macro. Equivalent costs should probably only be given to 29425 addresses with different numbers of registers on machines with 29426 lots of registers. 29427 29428 29429 File: gccint.info, Node: Scheduling, Next: Sections, Prev: Costs, Up: Target Macros 29430 29431 17.18 Adjusting the Instruction Scheduler 29432 ========================================= 29433 29434 The instruction scheduler may need a fair amount of machine-specific 29435 adjustment in order to produce good code. GCC provides several target 29436 hooks for this purpose. It is usually enough to define just a few of 29437 them: try the first ones in this list first. 29438 29439 -- Target Hook: int TARGET_SCHED_ISSUE_RATE (void) 29440 This hook returns the maximum number of instructions that can ever 29441 issue at the same time on the target machine. The default is one. 29442 Although the insn scheduler can define itself the possibility of 29443 issue an insn on the same cycle, the value can serve as an 29444 additional constraint to issue insns on the same simulated 29445 processor cycle (see hooks `TARGET_SCHED_REORDER' and 29446 `TARGET_SCHED_REORDER2'). This value must be constant over the 29447 entire compilation. If you need it to vary depending on what the 29448 instructions are, you must use `TARGET_SCHED_VARIABLE_ISSUE'. 29449 29450 -- Target Hook: int TARGET_SCHED_VARIABLE_ISSUE (FILE *FILE, int 29451 VERBOSE, rtx INSN, int MORE) 29452 This hook is executed by the scheduler after it has scheduled an 29453 insn from the ready list. It should return the number of insns 29454 which can still be issued in the current cycle. The default is 29455 `MORE - 1' for insns other than `CLOBBER' and `USE', which 29456 normally are not counted against the issue rate. You should 29457 define this hook if some insns take more machine resources than 29458 others, so that fewer insns can follow them in the same cycle. 29459 FILE is either a null pointer, or a stdio stream to write any 29460 debug output to. VERBOSE is the verbose level provided by 29461 `-fsched-verbose-N'. INSN is the instruction that was scheduled. 29462 29463 -- Target Hook: int TARGET_SCHED_ADJUST_COST (rtx INSN, rtx LINK, rtx 29464 DEP_INSN, int COST) 29465 This function corrects the value of COST based on the relationship 29466 between INSN and DEP_INSN through the dependence LINK. It should 29467 return the new value. The default is to make no adjustment to 29468 COST. This can be used for example to specify to the scheduler 29469 using the traditional pipeline description that an output- or 29470 anti-dependence does not incur the same cost as a data-dependence. 29471 If the scheduler using the automaton based pipeline description, 29472 the cost of anti-dependence is zero and the cost of 29473 output-dependence is maximum of one and the difference of latency 29474 times of the first and the second insns. If these values are not 29475 acceptable, you could use the hook to modify them too. See also 29476 *note Processor pipeline description::. 29477 29478 -- Target Hook: int TARGET_SCHED_ADJUST_PRIORITY (rtx INSN, int 29479 PRIORITY) 29480 This hook adjusts the integer scheduling priority PRIORITY of 29481 INSN. It should return the new priority. Increase the priority to 29482 execute INSN earlier, reduce the priority to execute INSN later. 29483 Do not define this hook if you do not need to adjust the 29484 scheduling priorities of insns. 29485 29486 -- Target Hook: int TARGET_SCHED_REORDER (FILE *FILE, int VERBOSE, rtx 29487 *READY, int *N_READYP, int CLOCK) 29488 This hook is executed by the scheduler after it has scheduled the 29489 ready list, to allow the machine description to reorder it (for 29490 example to combine two small instructions together on `VLIW' 29491 machines). FILE is either a null pointer, or a stdio stream to 29492 write any debug output to. VERBOSE is the verbose level provided 29493 by `-fsched-verbose-N'. READY is a pointer to the ready list of 29494 instructions that are ready to be scheduled. N_READYP is a 29495 pointer to the number of elements in the ready list. The scheduler 29496 reads the ready list in reverse order, starting with 29497 READY[*N_READYP-1] and going to READY[0]. CLOCK is the timer tick 29498 of the scheduler. You may modify the ready list and the number of 29499 ready insns. The return value is the number of insns that can 29500 issue this cycle; normally this is just `issue_rate'. See also 29501 `TARGET_SCHED_REORDER2'. 29502 29503 -- Target Hook: int TARGET_SCHED_REORDER2 (FILE *FILE, int VERBOSE, 29504 rtx *READY, int *N_READY, CLOCK) 29505 Like `TARGET_SCHED_REORDER', but called at a different time. That 29506 function is called whenever the scheduler starts a new cycle. 29507 This one is called once per iteration over a cycle, immediately 29508 after `TARGET_SCHED_VARIABLE_ISSUE'; it can reorder the ready list 29509 and return the number of insns to be scheduled in the same cycle. 29510 Defining this hook can be useful if there are frequent situations 29511 where scheduling one insn causes other insns to become ready in 29512 the same cycle. These other insns can then be taken into account 29513 properly. 29514 29515 -- Target Hook: void TARGET_SCHED_DEPENDENCIES_EVALUATION_HOOK (rtx 29516 HEAD, rtx TAIL) 29517 This hook is called after evaluation forward dependencies of insns 29518 in chain given by two parameter values (HEAD and TAIL 29519 correspondingly) but before insns scheduling of the insn chain. 29520 For example, it can be used for better insn classification if it 29521 requires analysis of dependencies. This hook can use backward and 29522 forward dependencies of the insn scheduler because they are already 29523 calculated. 29524 29525 -- Target Hook: void TARGET_SCHED_INIT (FILE *FILE, int VERBOSE, int 29526 MAX_READY) 29527 This hook is executed by the scheduler at the beginning of each 29528 block of instructions that are to be scheduled. FILE is either a 29529 null pointer, or a stdio stream to write any debug output to. 29530 VERBOSE is the verbose level provided by `-fsched-verbose-N'. 29531 MAX_READY is the maximum number of insns in the current scheduling 29532 region that can be live at the same time. This can be used to 29533 allocate scratch space if it is needed, e.g. by 29534 `TARGET_SCHED_REORDER'. 29535 29536 -- Target Hook: void TARGET_SCHED_FINISH (FILE *FILE, int VERBOSE) 29537 This hook is executed by the scheduler at the end of each block of 29538 instructions that are to be scheduled. It can be used to perform 29539 cleanup of any actions done by the other scheduling hooks. FILE 29540 is either a null pointer, or a stdio stream to write any debug 29541 output to. VERBOSE is the verbose level provided by 29542 `-fsched-verbose-N'. 29543 29544 -- Target Hook: void TARGET_SCHED_INIT_GLOBAL (FILE *FILE, int 29545 VERBOSE, int OLD_MAX_UID) 29546 This hook is executed by the scheduler after function level 29547 initializations. FILE is either a null pointer, or a stdio stream 29548 to write any debug output to. VERBOSE is the verbose level 29549 provided by `-fsched-verbose-N'. OLD_MAX_UID is the maximum insn 29550 uid when scheduling begins. 29551 29552 -- Target Hook: void TARGET_SCHED_FINISH_GLOBAL (FILE *FILE, int 29553 VERBOSE) 29554 This is the cleanup hook corresponding to 29555 `TARGET_SCHED_INIT_GLOBAL'. FILE is either a null pointer, or a 29556 stdio stream to write any debug output to. VERBOSE is the verbose 29557 level provided by `-fsched-verbose-N'. 29558 29559 -- Target Hook: int TARGET_SCHED_DFA_PRE_CYCLE_INSN (void) 29560 The hook returns an RTL insn. The automaton state used in the 29561 pipeline hazard recognizer is changed as if the insn were scheduled 29562 when the new simulated processor cycle starts. Usage of the hook 29563 may simplify the automaton pipeline description for some VLIW 29564 processors. If the hook is defined, it is used only for the 29565 automaton based pipeline description. The default is not to 29566 change the state when the new simulated processor cycle starts. 29567 29568 -- Target Hook: void TARGET_SCHED_INIT_DFA_PRE_CYCLE_INSN (void) 29569 The hook can be used to initialize data used by the previous hook. 29570 29571 -- Target Hook: int TARGET_SCHED_DFA_POST_CYCLE_INSN (void) 29572 The hook is analogous to `TARGET_SCHED_DFA_PRE_CYCLE_INSN' but used 29573 to changed the state as if the insn were scheduled when the new 29574 simulated processor cycle finishes. 29575 29576 -- Target Hook: void TARGET_SCHED_INIT_DFA_POST_CYCLE_INSN (void) 29577 The hook is analogous to `TARGET_SCHED_INIT_DFA_PRE_CYCLE_INSN' but 29578 used to initialize data used by the previous hook. 29579 29580 -- Target Hook: void TARGET_SCHED_DFA_PRE_CYCLE_ADVANCE (void) 29581 The hook to notify target that the current simulated cycle is 29582 about to finish. The hook is analogous to 29583 `TARGET_SCHED_DFA_PRE_CYCLE_INSN' but used to change the state in 29584 more complicated situations - e.g., when advancing state on a 29585 single insn is not enough. 29586 29587 -- Target Hook: void TARGET_SCHED_DFA_POST_CYCLE_ADVANCE (void) 29588 The hook to notify target that new simulated cycle has just 29589 started. The hook is analogous to 29590 `TARGET_SCHED_DFA_POST_CYCLE_INSN' but used to change the state in 29591 more complicated situations - e.g., when advancing state on a 29592 single insn is not enough. 29593 29594 -- Target Hook: int TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD 29595 (void) 29596 This hook controls better choosing an insn from the ready insn 29597 queue for the DFA-based insn scheduler. Usually the scheduler 29598 chooses the first insn from the queue. If the hook returns a 29599 positive value, an additional scheduler code tries all 29600 permutations of `TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD 29601 ()' subsequent ready insns to choose an insn whose issue will 29602 result in maximal number of issued insns on the same cycle. For 29603 the VLIW processor, the code could actually solve the problem of 29604 packing simple insns into the VLIW insn. Of course, if the rules 29605 of VLIW packing are described in the automaton. 29606 29607 This code also could be used for superscalar RISC processors. Let 29608 us consider a superscalar RISC processor with 3 pipelines. Some 29609 insns can be executed in pipelines A or B, some insns can be 29610 executed only in pipelines B or C, and one insn can be executed in 29611 pipeline B. The processor may issue the 1st insn into A and the 29612 2nd one into B. In this case, the 3rd insn will wait for freeing B 29613 until the next cycle. If the scheduler issues the 3rd insn the 29614 first, the processor could issue all 3 insns per cycle. 29615 29616 Actually this code demonstrates advantages of the automaton based 29617 pipeline hazard recognizer. We try quickly and easy many insn 29618 schedules to choose the best one. 29619 29620 The default is no multipass scheduling. 29621 29622 -- Target Hook: int 29623 TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD_GUARD (rtx) 29624 This hook controls what insns from the ready insn queue will be 29625 considered for the multipass insn scheduling. If the hook returns 29626 zero for insn passed as the parameter, the insn will be not chosen 29627 to be issued. 29628 29629 The default is that any ready insns can be chosen to be issued. 29630 29631 -- Target Hook: int TARGET_SCHED_DFA_NEW_CYCLE (FILE *, int, rtx, int, 29632 int, int *) 29633 This hook is called by the insn scheduler before issuing insn 29634 passed as the third parameter on given cycle. If the hook returns 29635 nonzero, the insn is not issued on given processors cycle. 29636 Instead of that, the processor cycle is advanced. If the value 29637 passed through the last parameter is zero, the insn ready queue is 29638 not sorted on the new cycle start as usually. The first parameter 29639 passes file for debugging output. The second one passes the 29640 scheduler verbose level of the debugging output. The forth and 29641 the fifth parameter values are correspondingly processor cycle on 29642 which the previous insn has been issued and the current processor 29643 cycle. 29644 29645 -- Target Hook: bool TARGET_SCHED_IS_COSTLY_DEPENDENCE (struct dep_def 29646 *_DEP, int COST, int DISTANCE) 29647 This hook is used to define which dependences are considered 29648 costly by the target, so costly that it is not advisable to 29649 schedule the insns that are involved in the dependence too close 29650 to one another. The parameters to this hook are as follows: The 29651 first parameter _DEP is the dependence being evaluated. The 29652 second parameter COST is the cost of the dependence, and the third 29653 parameter DISTANCE is the distance in cycles between the two insns. 29654 The hook returns `true' if considering the distance between the two 29655 insns the dependence between them is considered costly by the 29656 target, and `false' otherwise. 29657 29658 Defining this hook can be useful in multiple-issue out-of-order 29659 machines, where (a) it's practically hopeless to predict the 29660 actual data/resource delays, however: (b) there's a better chance 29661 to predict the actual grouping that will be formed, and (c) 29662 correctly emulating the grouping can be very important. In such 29663 targets one may want to allow issuing dependent insns closer to 29664 one another--i.e., closer than the dependence distance; however, 29665 not in cases of "costly dependences", which this hooks allows to 29666 define. 29667 29668 -- Target Hook: void TARGET_SCHED_H_I_D_EXTENDED (void) 29669 This hook is called by the insn scheduler after emitting a new 29670 instruction to the instruction stream. The hook notifies a target 29671 backend to extend its per instruction data structures. 29672 29673 -- Target Hook: void * TARGET_SCHED_ALLOC_SCHED_CONTEXT (void) 29674 Return a pointer to a store large enough to hold target scheduling 29675 context. 29676 29677 -- Target Hook: void TARGET_SCHED_INIT_SCHED_CONTEXT (void *TC, bool 29678 CLEAN_P) 29679 Initialize store pointed to by TC to hold target scheduling 29680 context. It CLEAN_P is true then initialize TC as if scheduler is 29681 at the beginning of the block. Otherwise, make a copy of the 29682 current context in TC. 29683 29684 -- Target Hook: void TARGET_SCHED_SET_SCHED_CONTEXT (void *TC) 29685 Copy target scheduling context pointer to by TC to the current 29686 context. 29687 29688 -- Target Hook: void TARGET_SCHED_CLEAR_SCHED_CONTEXT (void *TC) 29689 Deallocate internal data in target scheduling context pointed to 29690 by TC. 29691 29692 -- Target Hook: void TARGET_SCHED_FREE_SCHED_CONTEXT (void *TC) 29693 Deallocate a store for target scheduling context pointed to by TC. 29694 29695 -- Target Hook: void * TARGET_SCHED_ALLOC_SCHED_CONTEXT (void) 29696 Return a pointer to a store large enough to hold target scheduling 29697 context. 29698 29699 -- Target Hook: void TARGET_SCHED_INIT_SCHED_CONTEXT (void *TC, bool 29700 CLEAN_P) 29701 Initialize store pointed to by TC to hold target scheduling 29702 context. It CLEAN_P is true then initialize TC as if scheduler is 29703 at the beginning of the block. Otherwise, make a copy of the 29704 current context in TC. 29705 29706 -- Target Hook: void TARGET_SCHED_SET_SCHED_CONTEXT (void *TC) 29707 Copy target scheduling context pointer to by TC to the current 29708 context. 29709 29710 -- Target Hook: void TARGET_SCHED_CLEAR_SCHED_CONTEXT (void *TC) 29711 Deallocate internal data in target scheduling context pointed to 29712 by TC. 29713 29714 -- Target Hook: void TARGET_SCHED_FREE_SCHED_CONTEXT (void *TC) 29715 Deallocate a store for target scheduling context pointed to by TC. 29716 29717 -- Target Hook: int TARGET_SCHED_SPECULATE_INSN (rtx INSN, int 29718 REQUEST, rtx *NEW_PAT) 29719 This hook is called by the insn scheduler when INSN has only 29720 speculative dependencies and therefore can be scheduled 29721 speculatively. The hook is used to check if the pattern of INSN 29722 has a speculative version and, in case of successful check, to 29723 generate that speculative pattern. The hook should return 1, if 29724 the instruction has a speculative form, or -1, if it doesn't. 29725 REQUEST describes the type of requested speculation. If the 29726 return value equals 1 then NEW_PAT is assigned the generated 29727 speculative pattern. 29728 29729 -- Target Hook: int TARGET_SCHED_NEEDS_BLOCK_P (rtx INSN) 29730 This hook is called by the insn scheduler during generation of 29731 recovery code for INSN. It should return nonzero, if the 29732 corresponding check instruction should branch to recovery code, or 29733 zero otherwise. 29734 29735 -- Target Hook: rtx TARGET_SCHED_GEN_CHECK (rtx INSN, rtx LABEL, int 29736 MUTATE_P) 29737 This hook is called by the insn scheduler to generate a pattern 29738 for recovery check instruction. If MUTATE_P is zero, then INSN is 29739 a speculative instruction for which the check should be generated. 29740 LABEL is either a label of a basic block, where recovery code 29741 should be emitted, or a null pointer, when requested check doesn't 29742 branch to recovery code (a simple check). If MUTATE_P is nonzero, 29743 then a pattern for a branchy check corresponding to a simple check 29744 denoted by INSN should be generated. In this case LABEL can't be 29745 null. 29746 29747 -- Target Hook: int 29748 TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD_GUARD_SPEC (rtx INSN) 29749 This hook is used as a workaround for 29750 `TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD_GUARD' not being 29751 called on the first instruction of the ready list. The hook is 29752 used to discard speculative instruction that stand first in the 29753 ready list from being scheduled on the current cycle. For 29754 non-speculative instructions, the hook should always return 29755 nonzero. For example, in the ia64 backend the hook is used to 29756 cancel data speculative insns when the ALAT table is nearly full. 29757 29758 -- Target Hook: void TARGET_SCHED_SET_SCHED_FLAGS (unsigned int 29759 *FLAGS, spec_info_t SPEC_INFO) 29760 This hook is used by the insn scheduler to find out what features 29761 should be enabled/used. FLAGS initially may have either the 29762 SCHED_RGN or SCHED_EBB bit set. This denotes the scheduler pass 29763 for which the data should be provided. The target backend should 29764 modify FLAGS by modifying the bits corresponding to the following 29765 features: USE_DEPS_LIST, USE_GLAT, DETACH_LIFE_INFO, and 29766 DO_SPECULATION. For the DO_SPECULATION feature an additional 29767 structure SPEC_INFO should be filled by the target. The structure 29768 describes speculation types that can be used in the scheduler. 29769 29770 -- Target Hook: int TARGET_SCHED_SMS_RES_MII (struct ddg *G) 29771 This hook is called by the swing modulo scheduler to calculate a 29772 resource-based lower bound which is based on the resources 29773 available in the machine and the resources required by each 29774 instruction. The target backend can use G to calculate such 29775 bound. A very simple lower bound will be used in case this hook 29776 is not implemented: the total number of instructions divided by 29777 the issue rate. 29778 29779 29780 File: gccint.info, Node: Sections, Next: PIC, Prev: Scheduling, Up: Target Macros 29781 29782 17.19 Dividing the Output into Sections (Texts, Data, ...) 29783 ========================================================== 29784 29785 An object file is divided into sections containing different types of 29786 data. In the most common case, there are three sections: the "text 29787 section", which holds instructions and read-only data; the "data 29788 section", which holds initialized writable data; and the "bss section", 29789 which holds uninitialized data. Some systems have other kinds of 29790 sections. 29791 29792 `varasm.c' provides several well-known sections, such as 29793 `text_section', `data_section' and `bss_section'. The normal way of 29794 controlling a `FOO_section' variable is to define the associated 29795 `FOO_SECTION_ASM_OP' macro, as described below. The macros are only 29796 read once, when `varasm.c' initializes itself, so their values must be 29797 run-time constants. They may however depend on command-line flags. 29798 29799 _Note:_ Some run-time files, such `crtstuff.c', also make use of the 29800 `FOO_SECTION_ASM_OP' macros, and expect them to be string literals. 29801 29802 Some assemblers require a different string to be written every time a 29803 section is selected. If your assembler falls into this category, you 29804 should define the `TARGET_ASM_INIT_SECTIONS' hook and use 29805 `get_unnamed_section' to set up the sections. 29806 29807 You must always create a `text_section', either by defining 29808 `TEXT_SECTION_ASM_OP' or by initializing `text_section' in 29809 `TARGET_ASM_INIT_SECTIONS'. The same is true of `data_section' and 29810 `DATA_SECTION_ASM_OP'. If you do not create a distinct 29811 `readonly_data_section', the default is to reuse `text_section'. 29812 29813 All the other `varasm.c' sections are optional, and are null if the 29814 target does not provide them. 29815 29816 -- Macro: TEXT_SECTION_ASM_OP 29817 A C expression whose value is a string, including spacing, 29818 containing the assembler operation that should precede 29819 instructions and read-only data. Normally `"\t.text"' is right. 29820 29821 -- Macro: HOT_TEXT_SECTION_NAME 29822 If defined, a C string constant for the name of the section 29823 containing most frequently executed functions of the program. If 29824 not defined, GCC will provide a default definition if the target 29825 supports named sections. 29826 29827 -- Macro: UNLIKELY_EXECUTED_TEXT_SECTION_NAME 29828 If defined, a C string constant for the name of the section 29829 containing unlikely executed functions in the program. 29830 29831 -- Macro: DATA_SECTION_ASM_OP 29832 A C expression whose value is a string, including spacing, 29833 containing the assembler operation to identify the following data 29834 as writable initialized data. Normally `"\t.data"' is right. 29835 29836 -- Macro: SDATA_SECTION_ASM_OP 29837 If defined, a C expression whose value is a string, including 29838 spacing, containing the assembler operation to identify the 29839 following data as initialized, writable small data. 29840 29841 -- Macro: READONLY_DATA_SECTION_ASM_OP 29842 A C expression whose value is a string, including spacing, 29843 containing the assembler operation to identify the following data 29844 as read-only initialized data. 29845 29846 -- Macro: BSS_SECTION_ASM_OP 29847 If defined, a C expression whose value is a string, including 29848 spacing, containing the assembler operation to identify the 29849 following data as uninitialized global data. If not defined, and 29850 neither `ASM_OUTPUT_BSS' nor `ASM_OUTPUT_ALIGNED_BSS' are defined, 29851 uninitialized global data will be output in the data section if 29852 `-fno-common' is passed, otherwise `ASM_OUTPUT_COMMON' will be 29853 used. 29854 29855 -- Macro: SBSS_SECTION_ASM_OP 29856 If defined, a C expression whose value is a string, including 29857 spacing, containing the assembler operation to identify the 29858 following data as uninitialized, writable small data. 29859 29860 -- Macro: INIT_SECTION_ASM_OP 29861 If defined, a C expression whose value is a string, including 29862 spacing, containing the assembler operation to identify the 29863 following data as initialization code. If not defined, GCC will 29864 assume such a section does not exist. This section has no 29865 corresponding `init_section' variable; it is used entirely in 29866 runtime code. 29867 29868 -- Macro: FINI_SECTION_ASM_OP 29869 If defined, a C expression whose value is a string, including 29870 spacing, containing the assembler operation to identify the 29871 following data as finalization code. If not defined, GCC will 29872 assume such a section does not exist. This section has no 29873 corresponding `fini_section' variable; it is used entirely in 29874 runtime code. 29875 29876 -- Macro: INIT_ARRAY_SECTION_ASM_OP 29877 If defined, a C expression whose value is a string, including 29878 spacing, containing the assembler operation to identify the 29879 following data as part of the `.init_array' (or equivalent) 29880 section. If not defined, GCC will assume such a section does not 29881 exist. Do not define both this macro and `INIT_SECTION_ASM_OP'. 29882 29883 -- Macro: FINI_ARRAY_SECTION_ASM_OP 29884 If defined, a C expression whose value is a string, including 29885 spacing, containing the assembler operation to identify the 29886 following data as part of the `.fini_array' (or equivalent) 29887 section. If not defined, GCC will assume such a section does not 29888 exist. Do not define both this macro and `FINI_SECTION_ASM_OP'. 29889 29890 -- Macro: CRT_CALL_STATIC_FUNCTION (SECTION_OP, FUNCTION) 29891 If defined, an ASM statement that switches to a different section 29892 via SECTION_OP, calls FUNCTION, and switches back to the text 29893 section. This is used in `crtstuff.c' if `INIT_SECTION_ASM_OP' or 29894 `FINI_SECTION_ASM_OP' to calls to initialization and finalization 29895 functions from the init and fini sections. By default, this macro 29896 uses a simple function call. Some ports need hand-crafted 29897 assembly code to avoid dependencies on registers initialized in 29898 the function prologue or to ensure that constant pools don't end 29899 up too far way in the text section. 29900 29901 -- Macro: TARGET_LIBGCC_SDATA_SECTION 29902 If defined, a string which names the section into which small 29903 variables defined in crtstuff and libgcc should go. This is useful 29904 when the target has options for optimizing access to small data, 29905 and you want the crtstuff and libgcc routines to be conservative 29906 in what they expect of your application yet liberal in what your 29907 application expects. For example, for targets with a `.sdata' 29908 section (like MIPS), you could compile crtstuff with `-G 0' so 29909 that it doesn't require small data support from your application, 29910 but use this macro to put small data into `.sdata' so that your 29911 application can access these variables whether it uses small data 29912 or not. 29913 29914 -- Macro: FORCE_CODE_SECTION_ALIGN 29915 If defined, an ASM statement that aligns a code section to some 29916 arbitrary boundary. This is used to force all fragments of the 29917 `.init' and `.fini' sections to have to same alignment and thus 29918 prevent the linker from having to add any padding. 29919 29920 -- Macro: JUMP_TABLES_IN_TEXT_SECTION 29921 Define this macro to be an expression with a nonzero value if jump 29922 tables (for `tablejump' insns) should be output in the text 29923 section, along with the assembler instructions. Otherwise, the 29924 readonly data section is used. 29925 29926 This macro is irrelevant if there is no separate readonly data 29927 section. 29928 29929 -- Target Hook: void TARGET_ASM_INIT_SECTIONS (void) 29930 Define this hook if you need to do something special to set up the 29931 `varasm.c' sections, or if your target has some special sections 29932 of its own that you need to create. 29933 29934 GCC calls this hook after processing the command line, but before 29935 writing any assembly code, and before calling any of the 29936 section-returning hooks described below. 29937 29938 -- Target Hook: TARGET_ASM_RELOC_RW_MASK (void) 29939 Return a mask describing how relocations should be treated when 29940 selecting sections. Bit 1 should be set if global relocations 29941 should be placed in a read-write section; bit 0 should be set if 29942 local relocations should be placed in a read-write section. 29943 29944 The default version of this function returns 3 when `-fpic' is in 29945 effect, and 0 otherwise. The hook is typically redefined when the 29946 target cannot support (some kinds of) dynamic relocations in 29947 read-only sections even in executables. 29948 29949 -- Target Hook: section * TARGET_ASM_SELECT_SECTION (tree EXP, int 29950 RELOC, unsigned HOST_WIDE_INT ALIGN) 29951 Return the section into which EXP should be placed. You can 29952 assume that EXP is either a `VAR_DECL' node or a constant of some 29953 sort. RELOC indicates whether the initial value of EXP requires 29954 link-time relocations. Bit 0 is set when variable contains local 29955 relocations only, while bit 1 is set for global relocations. 29956 ALIGN is the constant alignment in bits. 29957 29958 The default version of this function takes care of putting 29959 read-only variables in `readonly_data_section'. 29960 29961 See also USE_SELECT_SECTION_FOR_FUNCTIONS. 29962 29963 -- Macro: USE_SELECT_SECTION_FOR_FUNCTIONS 29964 Define this macro if you wish TARGET_ASM_SELECT_SECTION to be 29965 called for `FUNCTION_DECL's as well as for variables and constants. 29966 29967 In the case of a `FUNCTION_DECL', RELOC will be zero if the 29968 function has been determined to be likely to be called, and 29969 nonzero if it is unlikely to be called. 29970 29971 -- Target Hook: void TARGET_ASM_UNIQUE_SECTION (tree DECL, int RELOC) 29972 Build up a unique section name, expressed as a `STRING_CST' node, 29973 and assign it to `DECL_SECTION_NAME (DECL)'. As with 29974 `TARGET_ASM_SELECT_SECTION', RELOC indicates whether the initial 29975 value of EXP requires link-time relocations. 29976 29977 The default version of this function appends the symbol name to the 29978 ELF section name that would normally be used for the symbol. For 29979 example, the function `foo' would be placed in `.text.foo'. 29980 Whatever the actual target object format, this is often good 29981 enough. 29982 29983 -- Target Hook: section * TARGET_ASM_FUNCTION_RODATA_SECTION (tree 29984 DECL) 29985 Return the readonly data section associated with 29986 `DECL_SECTION_NAME (DECL)'. The default version of this function 29987 selects `.gnu.linkonce.r.name' if the function's section is 29988 `.gnu.linkonce.t.name', `.rodata.name' if function is in 29989 `.text.name', and the normal readonly-data section otherwise. 29990 29991 -- Target Hook: section * TARGET_ASM_SELECT_RTX_SECTION (enum 29992 machine_mode MODE, rtx X, unsigned HOST_WIDE_INT ALIGN) 29993 Return the section into which a constant X, of mode MODE, should 29994 be placed. You can assume that X is some kind of constant in RTL. 29995 The argument MODE is redundant except in the case of a 29996 `const_int' rtx. ALIGN is the constant alignment in bits. 29997 29998 The default version of this function takes care of putting symbolic 29999 constants in `flag_pic' mode in `data_section' and everything else 30000 in `readonly_data_section'. 30001 30002 -- Target Hook: void TARGET_MANGLE_DECL_ASSEMBLER_NAME (tree DECL, 30003 tree ID) 30004 Define this hook if you need to postprocess the assembler name 30005 generated by target-independent code. The ID provided to this 30006 hook will be the computed name (e.g., the macro `DECL_NAME' of the 30007 DECL in C, or the mangled name of the DECL in C++). The return 30008 value of the hook is an `IDENTIFIER_NODE' for the appropriate 30009 mangled name on your target system. The default implementation of 30010 this hook just returns the ID provided. 30011 30012 -- Target Hook: void TARGET_ENCODE_SECTION_INFO (tree DECL, rtx RTL, 30013 int NEW_DECL_P) 30014 Define this hook if references to a symbol or a constant must be 30015 treated differently depending on something about the variable or 30016 function named by the symbol (such as what section it is in). 30017 30018 The hook is executed immediately after rtl has been created for 30019 DECL, which may be a variable or function declaration or an entry 30020 in the constant pool. In either case, RTL is the rtl in question. 30021 Do _not_ use `DECL_RTL (DECL)' in this hook; that field may not 30022 have been initialized yet. 30023 30024 In the case of a constant, it is safe to assume that the rtl is a 30025 `mem' whose address is a `symbol_ref'. Most decls will also have 30026 this form, but that is not guaranteed. Global register variables, 30027 for instance, will have a `reg' for their rtl. (Normally the 30028 right thing to do with such unusual rtl is leave it alone.) 30029 30030 The NEW_DECL_P argument will be true if this is the first time 30031 that `TARGET_ENCODE_SECTION_INFO' has been invoked on this decl. 30032 It will be false for subsequent invocations, which will happen for 30033 duplicate declarations. Whether or not anything must be done for 30034 the duplicate declaration depends on whether the hook examines 30035 `DECL_ATTRIBUTES'. NEW_DECL_P is always true when the hook is 30036 called for a constant. 30037 30038 The usual thing for this hook to do is to record flags in the 30039 `symbol_ref', using `SYMBOL_REF_FLAG' or `SYMBOL_REF_FLAGS'. 30040 Historically, the name string was modified if it was necessary to 30041 encode more than one bit of information, but this practice is now 30042 discouraged; use `SYMBOL_REF_FLAGS'. 30043 30044 The default definition of this hook, `default_encode_section_info' 30045 in `varasm.c', sets a number of commonly-useful bits in 30046 `SYMBOL_REF_FLAGS'. Check whether the default does what you need 30047 before overriding it. 30048 30049 -- Target Hook: const char *TARGET_STRIP_NAME_ENCODING (const char 30050 *name) 30051 Decode NAME and return the real name part, sans the characters 30052 that `TARGET_ENCODE_SECTION_INFO' may have added. 30053 30054 -- Target Hook: bool TARGET_IN_SMALL_DATA_P (tree EXP) 30055 Returns true if EXP should be placed into a "small data" section. 30056 The default version of this hook always returns false. 30057 30058 -- Variable: Target Hook bool TARGET_HAVE_SRODATA_SECTION 30059 Contains the value true if the target places read-only "small 30060 data" into a separate section. The default value is false. 30061 30062 -- Target Hook: bool TARGET_BINDS_LOCAL_P (tree EXP) 30063 Returns true if EXP names an object for which name resolution 30064 rules must resolve to the current "module" (dynamic shared library 30065 or executable image). 30066 30067 The default version of this hook implements the name resolution 30068 rules for ELF, which has a looser model of global name binding 30069 than other currently supported object file formats. 30070 30071 -- Variable: Target Hook bool TARGET_HAVE_TLS 30072 Contains the value true if the target supports thread-local 30073 storage. The default value is false. 30074 30075 30076 File: gccint.info, Node: PIC, Next: Assembler Format, Prev: Sections, Up: Target Macros 30077 30078 17.20 Position Independent Code 30079 =============================== 30080 30081 This section describes macros that help implement generation of position 30082 independent code. Simply defining these macros is not enough to 30083 generate valid PIC; you must also add support to the macros 30084 `GO_IF_LEGITIMATE_ADDRESS' and `PRINT_OPERAND_ADDRESS', as well as 30085 `LEGITIMIZE_ADDRESS'. You must modify the definition of `movsi' to do 30086 something appropriate when the source operand contains a symbolic 30087 address. You may also need to alter the handling of switch statements 30088 so that they use relative addresses. 30089 30090 -- Macro: PIC_OFFSET_TABLE_REGNUM 30091 The register number of the register used to address a table of 30092 static data addresses in memory. In some cases this register is 30093 defined by a processor's "application binary interface" (ABI). 30094 When this macro is defined, RTL is generated for this register 30095 once, as with the stack pointer and frame pointer registers. If 30096 this macro is not defined, it is up to the machine-dependent files 30097 to allocate such a register (if necessary). Note that this 30098 register must be fixed when in use (e.g. when `flag_pic' is true). 30099 30100 -- Macro: PIC_OFFSET_TABLE_REG_CALL_CLOBBERED 30101 Define this macro if the register defined by 30102 `PIC_OFFSET_TABLE_REGNUM' is clobbered by calls. Do not define 30103 this macro if `PIC_OFFSET_TABLE_REGNUM' is not defined. 30104 30105 -- Macro: LEGITIMATE_PIC_OPERAND_P (X) 30106 A C expression that is nonzero if X is a legitimate immediate 30107 operand on the target machine when generating position independent 30108 code. You can assume that X satisfies `CONSTANT_P', so you need 30109 not check this. You can also assume FLAG_PIC is true, so you need 30110 not check it either. You need not define this macro if all 30111 constants (including `SYMBOL_REF') can be immediate operands when 30112 generating position independent code. 30113 30114 30115 File: gccint.info, Node: Assembler Format, Next: Debugging Info, Prev: PIC, Up: Target Macros 30116 30117 17.21 Defining the Output Assembler Language 30118 ============================================ 30119 30120 This section describes macros whose principal purpose is to describe how 30121 to write instructions in assembler language--rather than what the 30122 instructions do. 30123 30124 * Menu: 30125 30126 * File Framework:: Structural information for the assembler file. 30127 * Data Output:: Output of constants (numbers, strings, addresses). 30128 * Uninitialized Data:: Output of uninitialized variables. 30129 * Label Output:: Output and generation of labels. 30130 * Initialization:: General principles of initialization 30131 and termination routines. 30132 * Macros for Initialization:: 30133 Specific macros that control the handling of 30134 initialization and termination routines. 30135 * Instruction Output:: Output of actual instructions. 30136 * Dispatch Tables:: Output of jump tables. 30137 * Exception Region Output:: Output of exception region code. 30138 * Alignment Output:: Pseudo ops for alignment and skipping data. 30139 30140 30141 File: gccint.info, Node: File Framework, Next: Data Output, Up: Assembler Format 30142 30143 17.21.1 The Overall Framework of an Assembler File 30144 -------------------------------------------------- 30145 30146 This describes the overall framework of an assembly file. 30147 30148 -- Target Hook: void TARGET_ASM_FILE_START () 30149 Output to `asm_out_file' any text which the assembler expects to 30150 find at the beginning of a file. The default behavior is 30151 controlled by two flags, documented below. Unless your target's 30152 assembler is quite unusual, if you override the default, you 30153 should call `default_file_start' at some point in your target 30154 hook. This lets other target files rely on these variables. 30155 30156 -- Target Hook: bool TARGET_ASM_FILE_START_APP_OFF 30157 If this flag is true, the text of the macro `ASM_APP_OFF' will be 30158 printed as the very first line in the assembly file, unless 30159 `-fverbose-asm' is in effect. (If that macro has been defined to 30160 the empty string, this variable has no effect.) With the normal 30161 definition of `ASM_APP_OFF', the effect is to notify the GNU 30162 assembler that it need not bother stripping comments or extra 30163 whitespace from its input. This allows it to work a bit faster. 30164 30165 The default is false. You should not set it to true unless you 30166 have verified that your port does not generate any extra 30167 whitespace or comments that will cause GAS to issue errors in 30168 NO_APP mode. 30169 30170 -- Target Hook: bool TARGET_ASM_FILE_START_FILE_DIRECTIVE 30171 If this flag is true, `output_file_directive' will be called for 30172 the primary source file, immediately after printing `ASM_APP_OFF' 30173 (if that is enabled). Most ELF assemblers expect this to be done. 30174 The default is false. 30175 30176 -- Target Hook: void TARGET_ASM_FILE_END () 30177 Output to `asm_out_file' any text which the assembler expects to 30178 find at the end of a file. The default is to output nothing. 30179 30180 -- Function: void file_end_indicate_exec_stack () 30181 Some systems use a common convention, the `.note.GNU-stack' 30182 special section, to indicate whether or not an object file relies 30183 on the stack being executable. If your system uses this 30184 convention, you should define `TARGET_ASM_FILE_END' to this 30185 function. If you need to do other things in that hook, have your 30186 hook function call this function. 30187 30188 -- Macro: ASM_COMMENT_START 30189 A C string constant describing how to begin a comment in the target 30190 assembler language. The compiler assumes that the comment will 30191 end at the end of the line. 30192 30193 -- Macro: ASM_APP_ON 30194 A C string constant for text to be output before each `asm' 30195 statement or group of consecutive ones. Normally this is 30196 `"#APP"', which is a comment that has no effect on most assemblers 30197 but tells the GNU assembler that it must check the lines that 30198 follow for all valid assembler constructs. 30199 30200 -- Macro: ASM_APP_OFF 30201 A C string constant for text to be output after each `asm' 30202 statement or group of consecutive ones. Normally this is 30203 `"#NO_APP"', which tells the GNU assembler to resume making the 30204 time-saving assumptions that are valid for ordinary compiler 30205 output. 30206 30207 -- Macro: ASM_OUTPUT_SOURCE_FILENAME (STREAM, NAME) 30208 A C statement to output COFF information or DWARF debugging 30209 information which indicates that filename NAME is the current 30210 source file to the stdio stream STREAM. 30211 30212 This macro need not be defined if the standard form of output for 30213 the file format in use is appropriate. 30214 30215 -- Macro: OUTPUT_QUOTED_STRING (STREAM, STRING) 30216 A C statement to output the string STRING to the stdio stream 30217 STREAM. If you do not call the function `output_quoted_string' in 30218 your config files, GCC will only call it to output filenames to 30219 the assembler source. So you can use it to canonicalize the format 30220 of the filename using this macro. 30221 30222 -- Macro: ASM_OUTPUT_IDENT (STREAM, STRING) 30223 A C statement to output something to the assembler file to handle a 30224 `#ident' directive containing the text STRING. If this macro is 30225 not defined, nothing is output for a `#ident' directive. 30226 30227 -- Target Hook: void TARGET_ASM_NAMED_SECTION (const char *NAME, 30228 unsigned int FLAGS, unsigned int ALIGN) 30229 Output assembly directives to switch to section NAME. The section 30230 should have attributes as specified by FLAGS, which is a bit mask 30231 of the `SECTION_*' flags defined in `output.h'. If ALIGN is 30232 nonzero, it contains an alignment in bytes to be used for the 30233 section, otherwise some target default should be used. Only 30234 targets that must specify an alignment within the section 30235 directive need pay attention to ALIGN - we will still use 30236 `ASM_OUTPUT_ALIGN'. 30237 30238 -- Target Hook: bool TARGET_HAVE_NAMED_SECTIONS 30239 This flag is true if the target supports 30240 `TARGET_ASM_NAMED_SECTION'. 30241 30242 -- Target Hook: bool TARGET_HAVE_SWITCHABLE_BSS_SECTIONS 30243 This flag is true if we can create zeroed data by switching to a 30244 BSS section and then using `ASM_OUTPUT_SKIP' to allocate the space. 30245 This is true on most ELF targets. 30246 30247 -- Target Hook: unsigned int TARGET_SECTION_TYPE_FLAGS (tree DECL, 30248 const char *NAME, int RELOC) 30249 Choose a set of section attributes for use by 30250 `TARGET_ASM_NAMED_SECTION' based on a variable or function decl, a 30251 section name, and whether or not the declaration's initializer may 30252 contain runtime relocations. DECL may be null, in which case 30253 read-write data should be assumed. 30254 30255 The default version of this function handles choosing code vs data, 30256 read-only vs read-write data, and `flag_pic'. You should only 30257 need to override this if your target has special flags that might 30258 be set via `__attribute__'. 30259 30260 -- Target Hook: int TARGET_ASM_RECORD_GCC_SWITCHES (print_switch_type 30261 TYPE, const char * TEXT) 30262 Provides the target with the ability to record the gcc command line 30263 switches that have been passed to the compiler, and options that 30264 are enabled. The TYPE argument specifies what is being recorded. 30265 It can take the following values: 30266 30267 `SWITCH_TYPE_PASSED' 30268 TEXT is a command line switch that has been set by the user. 30269 30270 `SWITCH_TYPE_ENABLED' 30271 TEXT is an option which has been enabled. This might be as a 30272 direct result of a command line switch, or because it is 30273 enabled by default or because it has been enabled as a side 30274 effect of a different command line switch. For example, the 30275 `-O2' switch enables various different individual 30276 optimization passes. 30277 30278 `SWITCH_TYPE_DESCRIPTIVE' 30279 TEXT is either NULL or some descriptive text which should be 30280 ignored. If TEXT is NULL then it is being used to warn the 30281 target hook that either recording is starting or ending. The 30282 first time TYPE is SWITCH_TYPE_DESCRIPTIVE and TEXT is NULL, 30283 the warning is for start up and the second time the warning 30284 is for wind down. This feature is to allow the target hook 30285 to make any necessary preparations before it starts to record 30286 switches and to perform any necessary tidying up after it has 30287 finished recording switches. 30288 30289 `SWITCH_TYPE_LINE_START' 30290 This option can be ignored by this target hook. 30291 30292 `SWITCH_TYPE_LINE_END' 30293 This option can be ignored by this target hook. 30294 30295 The hook's return value must be zero. Other return values may be 30296 supported in the future. 30297 30298 By default this hook is set to NULL, but an example implementation 30299 is provided for ELF based targets. Called ELF_RECORD_GCC_SWITCHES, 30300 it records the switches as ASCII text inside a new, string 30301 mergeable section in the assembler output file. The name of the 30302 new section is provided by the 30303 `TARGET_ASM_RECORD_GCC_SWITCHES_SECTION' target hook. 30304 30305 -- Target Hook: const char * TARGET_ASM_RECORD_GCC_SWITCHES_SECTION 30306 This is the name of the section that will be created by the example 30307 ELF implementation of the `TARGET_ASM_RECORD_GCC_SWITCHES' target 30308 hook. 30309 30310 30311 File: gccint.info, Node: Data Output, Next: Uninitialized Data, Prev: File Framework, Up: Assembler Format 30312 30313 17.21.2 Output of Data 30314 ---------------------- 30315 30316 -- Target Hook: const char * TARGET_ASM_BYTE_OP 30317 -- Target Hook: const char * TARGET_ASM_ALIGNED_HI_OP 30318 -- Target Hook: const char * TARGET_ASM_ALIGNED_SI_OP 30319 -- Target Hook: const char * TARGET_ASM_ALIGNED_DI_OP 30320 -- Target Hook: const char * TARGET_ASM_ALIGNED_TI_OP 30321 -- Target Hook: const char * TARGET_ASM_UNALIGNED_HI_OP 30322 -- Target Hook: const char * TARGET_ASM_UNALIGNED_SI_OP 30323 -- Target Hook: const char * TARGET_ASM_UNALIGNED_DI_OP 30324 -- Target Hook: const char * TARGET_ASM_UNALIGNED_TI_OP 30325 These hooks specify assembly directives for creating certain kinds 30326 of integer object. The `TARGET_ASM_BYTE_OP' directive creates a 30327 byte-sized object, the `TARGET_ASM_ALIGNED_HI_OP' one creates an 30328 aligned two-byte object, and so on. Any of the hooks may be 30329 `NULL', indicating that no suitable directive is available. 30330 30331 The compiler will print these strings at the start of a new line, 30332 followed immediately by the object's initial value. In most cases, 30333 the string should contain a tab, a pseudo-op, and then another tab. 30334 30335 -- Target Hook: bool TARGET_ASM_INTEGER (rtx X, unsigned int SIZE, int 30336 ALIGNED_P) 30337 The `assemble_integer' function uses this hook to output an 30338 integer object. X is the object's value, SIZE is its size in 30339 bytes and ALIGNED_P indicates whether it is aligned. The function 30340 should return `true' if it was able to output the object. If it 30341 returns false, `assemble_integer' will try to split the object 30342 into smaller parts. 30343 30344 The default implementation of this hook will use the 30345 `TARGET_ASM_BYTE_OP' family of strings, returning `false' when the 30346 relevant string is `NULL'. 30347 30348 -- Macro: OUTPUT_ADDR_CONST_EXTRA (STREAM, X, FAIL) 30349 A C statement to recognize RTX patterns that `output_addr_const' 30350 can't deal with, and output assembly code to STREAM corresponding 30351 to the pattern X. This may be used to allow machine-dependent 30352 `UNSPEC's to appear within constants. 30353 30354 If `OUTPUT_ADDR_CONST_EXTRA' fails to recognize a pattern, it must 30355 `goto fail', so that a standard error message is printed. If it 30356 prints an error message itself, by calling, for example, 30357 `output_operand_lossage', it may just complete normally. 30358 30359 -- Macro: ASM_OUTPUT_ASCII (STREAM, PTR, LEN) 30360 A C statement to output to the stdio stream STREAM an assembler 30361 instruction to assemble a string constant containing the LEN bytes 30362 at PTR. PTR will be a C expression of type `char *' and LEN a C 30363 expression of type `int'. 30364 30365 If the assembler has a `.ascii' pseudo-op as found in the Berkeley 30366 Unix assembler, do not define the macro `ASM_OUTPUT_ASCII'. 30367 30368 -- Macro: ASM_OUTPUT_FDESC (STREAM, DECL, N) 30369 A C statement to output word N of a function descriptor for DECL. 30370 This must be defined if `TARGET_VTABLE_USES_DESCRIPTORS' is 30371 defined, and is otherwise unused. 30372 30373 -- Macro: CONSTANT_POOL_BEFORE_FUNCTION 30374 You may define this macro as a C expression. You should define the 30375 expression to have a nonzero value if GCC should output the 30376 constant pool for a function before the code for the function, or 30377 a zero value if GCC should output the constant pool after the 30378 function. If you do not define this macro, the usual case, GCC 30379 will output the constant pool before the function. 30380 30381 -- Macro: ASM_OUTPUT_POOL_PROLOGUE (FILE, FUNNAME, FUNDECL, SIZE) 30382 A C statement to output assembler commands to define the start of 30383 the constant pool for a function. FUNNAME is a string giving the 30384 name of the function. Should the return type of the function be 30385 required, it can be obtained via FUNDECL. SIZE is the size, in 30386 bytes, of the constant pool that will be written immediately after 30387 this call. 30388 30389 If no constant-pool prefix is required, the usual case, this macro 30390 need not be defined. 30391 30392 -- Macro: ASM_OUTPUT_SPECIAL_POOL_ENTRY (FILE, X, MODE, ALIGN, 30393 LABELNO, JUMPTO) 30394 A C statement (with or without semicolon) to output a constant in 30395 the constant pool, if it needs special treatment. (This macro 30396 need not do anything for RTL expressions that can be output 30397 normally.) 30398 30399 The argument FILE is the standard I/O stream to output the 30400 assembler code on. X is the RTL expression for the constant to 30401 output, and MODE is the machine mode (in case X is a `const_int'). 30402 ALIGN is the required alignment for the value X; you should 30403 output an assembler directive to force this much alignment. 30404 30405 The argument LABELNO is a number to use in an internal label for 30406 the address of this pool entry. The definition of this macro is 30407 responsible for outputting the label definition at the proper 30408 place. Here is how to do this: 30409 30410 `(*targetm.asm_out.internal_label)' (FILE, "LC", LABELNO); 30411 30412 When you output a pool entry specially, you should end with a 30413 `goto' to the label JUMPTO. This will prevent the same pool entry 30414 from being output a second time in the usual manner. 30415 30416 You need not define this macro if it would do nothing. 30417 30418 -- Macro: ASM_OUTPUT_POOL_EPILOGUE (FILE FUNNAME FUNDECL SIZE) 30419 A C statement to output assembler commands to at the end of the 30420 constant pool for a function. FUNNAME is a string giving the name 30421 of the function. Should the return type of the function be 30422 required, you can obtain it via FUNDECL. SIZE is the size, in 30423 bytes, of the constant pool that GCC wrote immediately before this 30424 call. 30425 30426 If no constant-pool epilogue is required, the usual case, you need 30427 not define this macro. 30428 30429 -- Macro: IS_ASM_LOGICAL_LINE_SEPARATOR (C, STR) 30430 Define this macro as a C expression which is nonzero if C is used 30431 as a logical line separator by the assembler. STR points to the 30432 position in the string where C was found; this can be used if a 30433 line separator uses multiple characters. 30434 30435 If you do not define this macro, the default is that only the 30436 character `;' is treated as a logical line separator. 30437 30438 -- Target Hook: const char * TARGET_ASM_OPEN_PAREN 30439 -- Target Hook: const char * TARGET_ASM_CLOSE_PAREN 30440 These target hooks are C string constants, describing the syntax 30441 in the assembler for grouping arithmetic expressions. If not 30442 overridden, they default to normal parentheses, which is correct 30443 for most assemblers. 30444 30445 These macros are provided by `real.h' for writing the definitions of 30446 `ASM_OUTPUT_DOUBLE' and the like: 30447 30448 -- Macro: REAL_VALUE_TO_TARGET_SINGLE (X, L) 30449 -- Macro: REAL_VALUE_TO_TARGET_DOUBLE (X, L) 30450 -- Macro: REAL_VALUE_TO_TARGET_LONG_DOUBLE (X, L) 30451 -- Macro: REAL_VALUE_TO_TARGET_DECIMAL32 (X, L) 30452 -- Macro: REAL_VALUE_TO_TARGET_DECIMAL64 (X, L) 30453 -- Macro: REAL_VALUE_TO_TARGET_DECIMAL128 (X, L) 30454 These translate X, of type `REAL_VALUE_TYPE', to the target's 30455 floating point representation, and store its bit pattern in the 30456 variable L. For `REAL_VALUE_TO_TARGET_SINGLE' and 30457 `REAL_VALUE_TO_TARGET_DECIMAL32', this variable should be a simple 30458 `long int'. For the others, it should be an array of `long int'. 30459 The number of elements in this array is determined by the size of 30460 the desired target floating point data type: 32 bits of it go in 30461 each `long int' array element. Each array element holds 32 bits 30462 of the result, even if `long int' is wider than 32 bits on the 30463 host machine. 30464 30465 The array element values are designed so that you can print them 30466 out using `fprintf' in the order they should appear in the target 30467 machine's memory. 30468 30469 30470 File: gccint.info, Node: Uninitialized Data, Next: Label Output, Prev: Data Output, Up: Assembler Format 30471 30472 17.21.3 Output of Uninitialized Variables 30473 ----------------------------------------- 30474 30475 Each of the macros in this section is used to do the whole job of 30476 outputting a single uninitialized variable. 30477 30478 -- Macro: ASM_OUTPUT_COMMON (STREAM, NAME, SIZE, ROUNDED) 30479 A C statement (sans semicolon) to output to the stdio stream 30480 STREAM the assembler definition of a common-label named NAME whose 30481 size is SIZE bytes. The variable ROUNDED is the size rounded up 30482 to whatever alignment the caller wants. 30483 30484 Use the expression `assemble_name (STREAM, NAME)' to output the 30485 name itself; before and after that, output the additional 30486 assembler syntax for defining the name, and a newline. 30487 30488 This macro controls how the assembler definitions of uninitialized 30489 common global variables are output. 30490 30491 -- Macro: ASM_OUTPUT_ALIGNED_COMMON (STREAM, NAME, SIZE, ALIGNMENT) 30492 Like `ASM_OUTPUT_COMMON' except takes the required alignment as a 30493 separate, explicit argument. If you define this macro, it is used 30494 in place of `ASM_OUTPUT_COMMON', and gives you more flexibility in 30495 handling the required alignment of the variable. The alignment is 30496 specified as the number of bits. 30497 30498 -- Macro: ASM_OUTPUT_ALIGNED_DECL_COMMON (STREAM, DECL, NAME, SIZE, 30499 ALIGNMENT) 30500 Like `ASM_OUTPUT_ALIGNED_COMMON' except that DECL of the variable 30501 to be output, if there is one, or `NULL_TREE' if there is no 30502 corresponding variable. If you define this macro, GCC will use it 30503 in place of both `ASM_OUTPUT_COMMON' and 30504 `ASM_OUTPUT_ALIGNED_COMMON'. Define this macro when you need to 30505 see the variable's decl in order to chose what to output. 30506 30507 -- Macro: ASM_OUTPUT_BSS (STREAM, DECL, NAME, SIZE, ROUNDED) 30508 A C statement (sans semicolon) to output to the stdio stream 30509 STREAM the assembler definition of uninitialized global DECL named 30510 NAME whose size is SIZE bytes. The variable ROUNDED is the size 30511 rounded up to whatever alignment the caller wants. 30512 30513 Try to use function `asm_output_bss' defined in `varasm.c' when 30514 defining this macro. If unable, use the expression `assemble_name 30515 (STREAM, NAME)' to output the name itself; before and after that, 30516 output the additional assembler syntax for defining the name, and 30517 a newline. 30518 30519 There are two ways of handling global BSS. One is to define either 30520 this macro or its aligned counterpart, `ASM_OUTPUT_ALIGNED_BSS'. 30521 The other is to have `TARGET_ASM_SELECT_SECTION' return a 30522 switchable BSS section (*note 30523 TARGET_HAVE_SWITCHABLE_BSS_SECTIONS::). You do not need to do 30524 both. 30525 30526 Some languages do not have `common' data, and require a non-common 30527 form of global BSS in order to handle uninitialized globals 30528 efficiently. C++ is one example of this. However, if the target 30529 does not support global BSS, the front end may choose to make 30530 globals common in order to save space in the object file. 30531 30532 -- Macro: ASM_OUTPUT_ALIGNED_BSS (STREAM, DECL, NAME, SIZE, ALIGNMENT) 30533 Like `ASM_OUTPUT_BSS' except takes the required alignment as a 30534 separate, explicit argument. If you define this macro, it is used 30535 in place of `ASM_OUTPUT_BSS', and gives you more flexibility in 30536 handling the required alignment of the variable. The alignment is 30537 specified as the number of bits. 30538 30539 Try to use function `asm_output_aligned_bss' defined in file 30540 `varasm.c' when defining this macro. 30541 30542 -- Macro: ASM_OUTPUT_LOCAL (STREAM, NAME, SIZE, ROUNDED) 30543 A C statement (sans semicolon) to output to the stdio stream 30544 STREAM the assembler definition of a local-common-label named NAME 30545 whose size is SIZE bytes. The variable ROUNDED is the size 30546 rounded up to whatever alignment the caller wants. 30547 30548 Use the expression `assemble_name (STREAM, NAME)' to output the 30549 name itself; before and after that, output the additional 30550 assembler syntax for defining the name, and a newline. 30551 30552 This macro controls how the assembler definitions of uninitialized 30553 static variables are output. 30554 30555 -- Macro: ASM_OUTPUT_ALIGNED_LOCAL (STREAM, NAME, SIZE, ALIGNMENT) 30556 Like `ASM_OUTPUT_LOCAL' except takes the required alignment as a 30557 separate, explicit argument. If you define this macro, it is used 30558 in place of `ASM_OUTPUT_LOCAL', and gives you more flexibility in 30559 handling the required alignment of the variable. The alignment is 30560 specified as the number of bits. 30561 30562 -- Macro: ASM_OUTPUT_ALIGNED_DECL_LOCAL (STREAM, DECL, NAME, SIZE, 30563 ALIGNMENT) 30564 Like `ASM_OUTPUT_ALIGNED_DECL' except that DECL of the variable to 30565 be output, if there is one, or `NULL_TREE' if there is no 30566 corresponding variable. If you define this macro, GCC will use it 30567 in place of both `ASM_OUTPUT_DECL' and `ASM_OUTPUT_ALIGNED_DECL'. 30568 Define this macro when you need to see the variable's decl in 30569 order to chose what to output. 30570 30571 30572 File: gccint.info, Node: Label Output, Next: Initialization, Prev: Uninitialized Data, Up: Assembler Format 30573 30574 17.21.4 Output and Generation of Labels 30575 --------------------------------------- 30576 30577 This is about outputting labels. 30578 30579 -- Macro: ASM_OUTPUT_LABEL (STREAM, NAME) 30580 A C statement (sans semicolon) to output to the stdio stream 30581 STREAM the assembler definition of a label named NAME. Use the 30582 expression `assemble_name (STREAM, NAME)' to output the name 30583 itself; before and after that, output the additional assembler 30584 syntax for defining the name, and a newline. A default definition 30585 of this macro is provided which is correct for most systems. 30586 30587 -- Macro: ASM_OUTPUT_INTERNAL_LABEL (STREAM, NAME) 30588 Identical to `ASM_OUTPUT_LABEL', except that NAME is known to 30589 refer to a compiler-generated label. The default definition uses 30590 `assemble_name_raw', which is like `assemble_name' except that it 30591 is more efficient. 30592 30593 -- Macro: SIZE_ASM_OP 30594 A C string containing the appropriate assembler directive to 30595 specify the size of a symbol, without any arguments. On systems 30596 that use ELF, the default (in `config/elfos.h') is `"\t.size\t"'; 30597 on other systems, the default is not to define this macro. 30598 30599 Define this macro only if it is correct to use the default 30600 definitions of `ASM_OUTPUT_SIZE_DIRECTIVE' and 30601 `ASM_OUTPUT_MEASURED_SIZE' for your system. If you need your own 30602 custom definitions of those macros, or if you do not need explicit 30603 symbol sizes at all, do not define this macro. 30604 30605 -- Macro: ASM_OUTPUT_SIZE_DIRECTIVE (STREAM, NAME, SIZE) 30606 A C statement (sans semicolon) to output to the stdio stream 30607 STREAM a directive telling the assembler that the size of the 30608 symbol NAME is SIZE. SIZE is a `HOST_WIDE_INT'. If you define 30609 `SIZE_ASM_OP', a default definition of this macro is provided. 30610 30611 -- Macro: ASM_OUTPUT_MEASURED_SIZE (STREAM, NAME) 30612 A C statement (sans semicolon) to output to the stdio stream 30613 STREAM a directive telling the assembler to calculate the size of 30614 the symbol NAME by subtracting its address from the current 30615 address. 30616 30617 If you define `SIZE_ASM_OP', a default definition of this macro is 30618 provided. The default assumes that the assembler recognizes a 30619 special `.' symbol as referring to the current address, and can 30620 calculate the difference between this and another symbol. If your 30621 assembler does not recognize `.' or cannot do calculations with 30622 it, you will need to redefine `ASM_OUTPUT_MEASURED_SIZE' to use 30623 some other technique. 30624 30625 -- Macro: TYPE_ASM_OP 30626 A C string containing the appropriate assembler directive to 30627 specify the type of a symbol, without any arguments. On systems 30628 that use ELF, the default (in `config/elfos.h') is `"\t.type\t"'; 30629 on other systems, the default is not to define this macro. 30630 30631 Define this macro only if it is correct to use the default 30632 definition of `ASM_OUTPUT_TYPE_DIRECTIVE' for your system. If you 30633 need your own custom definition of this macro, or if you do not 30634 need explicit symbol types at all, do not define this macro. 30635 30636 -- Macro: TYPE_OPERAND_FMT 30637 A C string which specifies (using `printf' syntax) the format of 30638 the second operand to `TYPE_ASM_OP'. On systems that use ELF, the 30639 default (in `config/elfos.h') is `"@%s"'; on other systems, the 30640 default is not to define this macro. 30641 30642 Define this macro only if it is correct to use the default 30643 definition of `ASM_OUTPUT_TYPE_DIRECTIVE' for your system. If you 30644 need your own custom definition of this macro, or if you do not 30645 need explicit symbol types at all, do not define this macro. 30646 30647 -- Macro: ASM_OUTPUT_TYPE_DIRECTIVE (STREAM, TYPE) 30648 A C statement (sans semicolon) to output to the stdio stream 30649 STREAM a directive telling the assembler that the type of the 30650 symbol NAME is TYPE. TYPE is a C string; currently, that string 30651 is always either `"function"' or `"object"', but you should not 30652 count on this. 30653 30654 If you define `TYPE_ASM_OP' and `TYPE_OPERAND_FMT', a default 30655 definition of this macro is provided. 30656 30657 -- Macro: ASM_DECLARE_FUNCTION_NAME (STREAM, NAME, DECL) 30658 A C statement (sans semicolon) to output to the stdio stream 30659 STREAM any text necessary for declaring the name NAME of a 30660 function which is being defined. This macro is responsible for 30661 outputting the label definition (perhaps using 30662 `ASM_OUTPUT_LABEL'). The argument DECL is the `FUNCTION_DECL' 30663 tree node representing the function. 30664 30665 If this macro is not defined, then the function name is defined in 30666 the usual manner as a label (by means of `ASM_OUTPUT_LABEL'). 30667 30668 You may wish to use `ASM_OUTPUT_TYPE_DIRECTIVE' in the definition 30669 of this macro. 30670 30671 -- Macro: ASM_DECLARE_FUNCTION_SIZE (STREAM, NAME, DECL) 30672 A C statement (sans semicolon) to output to the stdio stream 30673 STREAM any text necessary for declaring the size of a function 30674 which is being defined. The argument NAME is the name of the 30675 function. The argument DECL is the `FUNCTION_DECL' tree node 30676 representing the function. 30677 30678 If this macro is not defined, then the function size is not 30679 defined. 30680 30681 You may wish to use `ASM_OUTPUT_MEASURED_SIZE' in the definition 30682 of this macro. 30683 30684 -- Macro: ASM_DECLARE_OBJECT_NAME (STREAM, NAME, DECL) 30685 A C statement (sans semicolon) to output to the stdio stream 30686 STREAM any text necessary for declaring the name NAME of an 30687 initialized variable which is being defined. This macro must 30688 output the label definition (perhaps using `ASM_OUTPUT_LABEL'). 30689 The argument DECL is the `VAR_DECL' tree node representing the 30690 variable. 30691 30692 If this macro is not defined, then the variable name is defined in 30693 the usual manner as a label (by means of `ASM_OUTPUT_LABEL'). 30694 30695 You may wish to use `ASM_OUTPUT_TYPE_DIRECTIVE' and/or 30696 `ASM_OUTPUT_SIZE_DIRECTIVE' in the definition of this macro. 30697 30698 -- Macro: ASM_DECLARE_CONSTANT_NAME (STREAM, NAME, EXP, SIZE) 30699 A C statement (sans semicolon) to output to the stdio stream 30700 STREAM any text necessary for declaring the name NAME of a 30701 constant which is being defined. This macro is responsible for 30702 outputting the label definition (perhaps using 30703 `ASM_OUTPUT_LABEL'). The argument EXP is the value of the 30704 constant, and SIZE is the size of the constant in bytes. NAME 30705 will be an internal label. 30706 30707 If this macro is not defined, then the NAME is defined in the 30708 usual manner as a label (by means of `ASM_OUTPUT_LABEL'). 30709 30710 You may wish to use `ASM_OUTPUT_TYPE_DIRECTIVE' in the definition 30711 of this macro. 30712 30713 -- Macro: ASM_DECLARE_REGISTER_GLOBAL (STREAM, DECL, REGNO, NAME) 30714 A C statement (sans semicolon) to output to the stdio stream 30715 STREAM any text necessary for claiming a register REGNO for a 30716 global variable DECL with name NAME. 30717 30718 If you don't define this macro, that is equivalent to defining it 30719 to do nothing. 30720 30721 -- Macro: ASM_FINISH_DECLARE_OBJECT (STREAM, DECL, TOPLEVEL, ATEND) 30722 A C statement (sans semicolon) to finish up declaring a variable 30723 name once the compiler has processed its initializer fully and 30724 thus has had a chance to determine the size of an array when 30725 controlled by an initializer. This is used on systems where it's 30726 necessary to declare something about the size of the object. 30727 30728 If you don't define this macro, that is equivalent to defining it 30729 to do nothing. 30730 30731 You may wish to use `ASM_OUTPUT_SIZE_DIRECTIVE' and/or 30732 `ASM_OUTPUT_MEASURED_SIZE' in the definition of this macro. 30733 30734 -- Target Hook: void TARGET_ASM_GLOBALIZE_LABEL (FILE *STREAM, const 30735 char *NAME) 30736 This target hook is a function to output to the stdio stream 30737 STREAM some commands that will make the label NAME global; that 30738 is, available for reference from other files. 30739 30740 The default implementation relies on a proper definition of 30741 `GLOBAL_ASM_OP'. 30742 30743 -- Target Hook: void TARGET_ASM_GLOBALIZE_DECL_NAME (FILE *STREAM, 30744 tree DECL) 30745 This target hook is a function to output to the stdio stream 30746 STREAM some commands that will make the name associated with DECL 30747 global; that is, available for reference from other files. 30748 30749 The default implementation uses the TARGET_ASM_GLOBALIZE_LABEL 30750 target hook. 30751 30752 -- Macro: ASM_WEAKEN_LABEL (STREAM, NAME) 30753 A C statement (sans semicolon) to output to the stdio stream 30754 STREAM some commands that will make the label NAME weak; that is, 30755 available for reference from other files but only used if no other 30756 definition is available. Use the expression `assemble_name 30757 (STREAM, NAME)' to output the name itself; before and after that, 30758 output the additional assembler syntax for making that name weak, 30759 and a newline. 30760 30761 If you don't define this macro or `ASM_WEAKEN_DECL', GCC will not 30762 support weak symbols and you should not define the `SUPPORTS_WEAK' 30763 macro. 30764 30765 -- Macro: ASM_WEAKEN_DECL (STREAM, DECL, NAME, VALUE) 30766 Combines (and replaces) the function of `ASM_WEAKEN_LABEL' and 30767 `ASM_OUTPUT_WEAK_ALIAS', allowing access to the associated function 30768 or variable decl. If VALUE is not `NULL', this C statement should 30769 output to the stdio stream STREAM assembler code which defines 30770 (equates) the weak symbol NAME to have the value VALUE. If VALUE 30771 is `NULL', it should output commands to make NAME weak. 30772 30773 -- Macro: ASM_OUTPUT_WEAKREF (STREAM, DECL, NAME, VALUE) 30774 Outputs a directive that enables NAME to be used to refer to 30775 symbol VALUE with weak-symbol semantics. `decl' is the 30776 declaration of `name'. 30777 30778 -- Macro: SUPPORTS_WEAK 30779 A C expression which evaluates to true if the target supports weak 30780 symbols. 30781 30782 If you don't define this macro, `defaults.h' provides a default 30783 definition. If either `ASM_WEAKEN_LABEL' or `ASM_WEAKEN_DECL' is 30784 defined, the default definition is `1'; otherwise, it is `0'. 30785 Define this macro if you want to control weak symbol support with 30786 a compiler flag such as `-melf'. 30787 30788 -- Macro: MAKE_DECL_ONE_ONLY (DECL) 30789 A C statement (sans semicolon) to mark DECL to be emitted as a 30790 public symbol such that extra copies in multiple translation units 30791 will be discarded by the linker. Define this macro if your object 30792 file format provides support for this concept, such as the `COMDAT' 30793 section flags in the Microsoft Windows PE/COFF format, and this 30794 support requires changes to DECL, such as putting it in a separate 30795 section. 30796 30797 -- Macro: SUPPORTS_ONE_ONLY 30798 A C expression which evaluates to true if the target supports 30799 one-only semantics. 30800 30801 If you don't define this macro, `varasm.c' provides a default 30802 definition. If `MAKE_DECL_ONE_ONLY' is defined, the default 30803 definition is `1'; otherwise, it is `0'. Define this macro if you 30804 want to control one-only symbol support with a compiler flag, or if 30805 setting the `DECL_ONE_ONLY' flag is enough to mark a declaration to 30806 be emitted as one-only. 30807 30808 -- Target Hook: void TARGET_ASM_ASSEMBLE_VISIBILITY (tree DECL, const 30809 char *VISIBILITY) 30810 This target hook is a function to output to ASM_OUT_FILE some 30811 commands that will make the symbol(s) associated with DECL have 30812 hidden, protected or internal visibility as specified by 30813 VISIBILITY. 30814 30815 -- Macro: TARGET_WEAK_NOT_IN_ARCHIVE_TOC 30816 A C expression that evaluates to true if the target's linker 30817 expects that weak symbols do not appear in a static archive's 30818 table of contents. The default is `0'. 30819 30820 Leaving weak symbols out of an archive's table of contents means 30821 that, if a symbol will only have a definition in one translation 30822 unit and will have undefined references from other translation 30823 units, that symbol should not be weak. Defining this macro to be 30824 nonzero will thus have the effect that certain symbols that would 30825 normally be weak (explicit template instantiations, and vtables 30826 for polymorphic classes with noninline key methods) will instead 30827 be nonweak. 30828 30829 The C++ ABI requires this macro to be zero. Define this macro for 30830 targets where full C++ ABI compliance is impossible and where 30831 linker restrictions require weak symbols to be left out of a 30832 static archive's table of contents. 30833 30834 -- Macro: ASM_OUTPUT_EXTERNAL (STREAM, DECL, NAME) 30835 A C statement (sans semicolon) to output to the stdio stream 30836 STREAM any text necessary for declaring the name of an external 30837 symbol named NAME which is referenced in this compilation but not 30838 defined. The value of DECL is the tree node for the declaration. 30839 30840 This macro need not be defined if it does not need to output 30841 anything. The GNU assembler and most Unix assemblers don't 30842 require anything. 30843 30844 -- Target Hook: void TARGET_ASM_EXTERNAL_LIBCALL (rtx SYMREF) 30845 This target hook is a function to output to ASM_OUT_FILE an 30846 assembler pseudo-op to declare a library function name external. 30847 The name of the library function is given by SYMREF, which is a 30848 `symbol_ref'. 30849 30850 -- Target Hook: void TARGET_ASM_MARK_DECL_PRESERVED (tree DECL) 30851 This target hook is a function to output to ASM_OUT_FILE an 30852 assembler directive to annotate used symbol. Darwin target use 30853 .no_dead_code_strip directive. 30854 30855 -- Macro: ASM_OUTPUT_LABELREF (STREAM, NAME) 30856 A C statement (sans semicolon) to output to the stdio stream 30857 STREAM a reference in assembler syntax to a label named NAME. 30858 This should add `_' to the front of the name, if that is customary 30859 on your operating system, as it is in most Berkeley Unix systems. 30860 This macro is used in `assemble_name'. 30861 30862 -- Macro: ASM_OUTPUT_SYMBOL_REF (STREAM, SYM) 30863 A C statement (sans semicolon) to output a reference to 30864 `SYMBOL_REF' SYM. If not defined, `assemble_name' will be used to 30865 output the name of the symbol. This macro may be used to modify 30866 the way a symbol is referenced depending on information encoded by 30867 `TARGET_ENCODE_SECTION_INFO'. 30868 30869 -- Macro: ASM_OUTPUT_LABEL_REF (STREAM, BUF) 30870 A C statement (sans semicolon) to output a reference to BUF, the 30871 result of `ASM_GENERATE_INTERNAL_LABEL'. If not defined, 30872 `assemble_name' will be used to output the name of the symbol. 30873 This macro is not used by `output_asm_label', or the `%l' 30874 specifier that calls it; the intention is that this macro should 30875 be set when it is necessary to output a label differently when its 30876 address is being taken. 30877 30878 -- Target Hook: void TARGET_ASM_INTERNAL_LABEL (FILE *STREAM, const 30879 char *PREFIX, unsigned long LABELNO) 30880 A function to output to the stdio stream STREAM a label whose name 30881 is made from the string PREFIX and the number LABELNO. 30882 30883 It is absolutely essential that these labels be distinct from the 30884 labels used for user-level functions and variables. Otherwise, 30885 certain programs will have name conflicts with internal labels. 30886 30887 It is desirable to exclude internal labels from the symbol table 30888 of the object file. Most assemblers have a naming convention for 30889 labels that should be excluded; on many systems, the letter `L' at 30890 the beginning of a label has this effect. You should find out what 30891 convention your system uses, and follow it. 30892 30893 The default version of this function utilizes 30894 `ASM_GENERATE_INTERNAL_LABEL'. 30895 30896 -- Macro: ASM_OUTPUT_DEBUG_LABEL (STREAM, PREFIX, NUM) 30897 A C statement to output to the stdio stream STREAM a debug info 30898 label whose name is made from the string PREFIX and the number 30899 NUM. This is useful for VLIW targets, where debug info labels may 30900 need to be treated differently than branch target labels. On some 30901 systems, branch target labels must be at the beginning of 30902 instruction bundles, but debug info labels can occur in the middle 30903 of instruction bundles. 30904 30905 If this macro is not defined, then 30906 `(*targetm.asm_out.internal_label)' will be used. 30907 30908 -- Macro: ASM_GENERATE_INTERNAL_LABEL (STRING, PREFIX, NUM) 30909 A C statement to store into the string STRING a label whose name 30910 is made from the string PREFIX and the number NUM. 30911 30912 This string, when output subsequently by `assemble_name', should 30913 produce the output that `(*targetm.asm_out.internal_label)' would 30914 produce with the same PREFIX and NUM. 30915 30916 If the string begins with `*', then `assemble_name' will output 30917 the rest of the string unchanged. It is often convenient for 30918 `ASM_GENERATE_INTERNAL_LABEL' to use `*' in this way. If the 30919 string doesn't start with `*', then `ASM_OUTPUT_LABELREF' gets to 30920 output the string, and may change it. (Of course, 30921 `ASM_OUTPUT_LABELREF' is also part of your machine description, so 30922 you should know what it does on your machine.) 30923 30924 -- Macro: ASM_FORMAT_PRIVATE_NAME (OUTVAR, NAME, NUMBER) 30925 A C expression to assign to OUTVAR (which is a variable of type 30926 `char *') a newly allocated string made from the string NAME and 30927 the number NUMBER, with some suitable punctuation added. Use 30928 `alloca' to get space for the string. 30929 30930 The string will be used as an argument to `ASM_OUTPUT_LABELREF' to 30931 produce an assembler label for an internal static variable whose 30932 name is NAME. Therefore, the string must be such as to result in 30933 valid assembler code. The argument NUMBER is different each time 30934 this macro is executed; it prevents conflicts between 30935 similarly-named internal static variables in different scopes. 30936 30937 Ideally this string should not be a valid C identifier, to prevent 30938 any conflict with the user's own symbols. Most assemblers allow 30939 periods or percent signs in assembler symbols; putting at least 30940 one of these between the name and the number will suffice. 30941 30942 If this macro is not defined, a default definition will be provided 30943 which is correct for most systems. 30944 30945 -- Macro: ASM_OUTPUT_DEF (STREAM, NAME, VALUE) 30946 A C statement to output to the stdio stream STREAM assembler code 30947 which defines (equates) the symbol NAME to have the value VALUE. 30948 30949 If `SET_ASM_OP' is defined, a default definition is provided which 30950 is correct for most systems. 30951 30952 -- Macro: ASM_OUTPUT_DEF_FROM_DECLS (STREAM, DECL_OF_NAME, 30953 DECL_OF_VALUE) 30954 A C statement to output to the stdio stream STREAM assembler code 30955 which defines (equates) the symbol whose tree node is DECL_OF_NAME 30956 to have the value of the tree node DECL_OF_VALUE. This macro will 30957 be used in preference to `ASM_OUTPUT_DEF' if it is defined and if 30958 the tree nodes are available. 30959 30960 If `SET_ASM_OP' is defined, a default definition is provided which 30961 is correct for most systems. 30962 30963 -- Macro: TARGET_DEFERRED_OUTPUT_DEFS (DECL_OF_NAME, DECL_OF_VALUE) 30964 A C statement that evaluates to true if the assembler code which 30965 defines (equates) the symbol whose tree node is DECL_OF_NAME to 30966 have the value of the tree node DECL_OF_VALUE should be emitted 30967 near the end of the current compilation unit. The default is to 30968 not defer output of defines. This macro affects defines output by 30969 `ASM_OUTPUT_DEF' and `ASM_OUTPUT_DEF_FROM_DECLS'. 30970 30971 -- Macro: ASM_OUTPUT_WEAK_ALIAS (STREAM, NAME, VALUE) 30972 A C statement to output to the stdio stream STREAM assembler code 30973 which defines (equates) the weak symbol NAME to have the value 30974 VALUE. If VALUE is `NULL', it defines NAME as an undefined weak 30975 symbol. 30976 30977 Define this macro if the target only supports weak aliases; define 30978 `ASM_OUTPUT_DEF' instead if possible. 30979 30980 -- Macro: OBJC_GEN_METHOD_LABEL (BUF, IS_INST, CLASS_NAME, CAT_NAME, 30981 SEL_NAME) 30982 Define this macro to override the default assembler names used for 30983 Objective-C methods. 30984 30985 The default name is a unique method number followed by the name of 30986 the class (e.g. `_1_Foo'). For methods in categories, the name of 30987 the category is also included in the assembler name (e.g. 30988 `_1_Foo_Bar'). 30989 30990 These names are safe on most systems, but make debugging difficult 30991 since the method's selector is not present in the name. 30992 Therefore, particular systems define other ways of computing names. 30993 30994 BUF is an expression of type `char *' which gives you a buffer in 30995 which to store the name; its length is as long as CLASS_NAME, 30996 CAT_NAME and SEL_NAME put together, plus 50 characters extra. 30997 30998 The argument IS_INST specifies whether the method is an instance 30999 method or a class method; CLASS_NAME is the name of the class; 31000 CAT_NAME is the name of the category (or `NULL' if the method is 31001 not in a category); and SEL_NAME is the name of the selector. 31002 31003 On systems where the assembler can handle quoted names, you can 31004 use this macro to provide more human-readable names. 31005 31006 -- Macro: ASM_DECLARE_CLASS_REFERENCE (STREAM, NAME) 31007 A C statement (sans semicolon) to output to the stdio stream 31008 STREAM commands to declare that the label NAME is an Objective-C 31009 class reference. This is only needed for targets whose linkers 31010 have special support for NeXT-style runtimes. 31011 31012 -- Macro: ASM_DECLARE_UNRESOLVED_REFERENCE (STREAM, NAME) 31013 A C statement (sans semicolon) to output to the stdio stream 31014 STREAM commands to declare that the label NAME is an unresolved 31015 Objective-C class reference. This is only needed for targets 31016 whose linkers have special support for NeXT-style runtimes. 31017 31018 31019 File: gccint.info, Node: Initialization, Next: Macros for Initialization, Prev: Label Output, Up: Assembler Format 31020 31021 17.21.5 How Initialization Functions Are Handled 31022 ------------------------------------------------ 31023 31024 The compiled code for certain languages includes "constructors" (also 31025 called "initialization routines")--functions to initialize data in the 31026 program when the program is started. These functions need to be called 31027 before the program is "started"--that is to say, before `main' is 31028 called. 31029 31030 Compiling some languages generates "destructors" (also called 31031 "termination routines") that should be called when the program 31032 terminates. 31033 31034 To make the initialization and termination functions work, the compiler 31035 must output something in the assembler code to cause those functions to 31036 be called at the appropriate time. When you port the compiler to a new 31037 system, you need to specify how to do this. 31038 31039 There are two major ways that GCC currently supports the execution of 31040 initialization and termination functions. Each way has two variants. 31041 Much of the structure is common to all four variations. 31042 31043 The linker must build two lists of these functions--a list of 31044 initialization functions, called `__CTOR_LIST__', and a list of 31045 termination functions, called `__DTOR_LIST__'. 31046 31047 Each list always begins with an ignored function pointer (which may 31048 hold 0, -1, or a count of the function pointers after it, depending on 31049 the environment). This is followed by a series of zero or more function 31050 pointers to constructors (or destructors), followed by a function 31051 pointer containing zero. 31052 31053 Depending on the operating system and its executable file format, 31054 either `crtstuff.c' or `libgcc2.c' traverses these lists at startup 31055 time and exit time. Constructors are called in reverse order of the 31056 list; destructors in forward order. 31057 31058 The best way to handle static constructors works only for object file 31059 formats which provide arbitrarily-named sections. A section is set 31060 aside for a list of constructors, and another for a list of destructors. 31061 Traditionally these are called `.ctors' and `.dtors'. Each object file 31062 that defines an initialization function also puts a word in the 31063 constructor section to point to that function. The linker accumulates 31064 all these words into one contiguous `.ctors' section. Termination 31065 functions are handled similarly. 31066 31067 This method will be chosen as the default by `target-def.h' if 31068 `TARGET_ASM_NAMED_SECTION' is defined. A target that does not support 31069 arbitrary sections, but does support special designated constructor and 31070 destructor sections may define `CTORS_SECTION_ASM_OP' and 31071 `DTORS_SECTION_ASM_OP' to achieve the same effect. 31072 31073 When arbitrary sections are available, there are two variants, 31074 depending upon how the code in `crtstuff.c' is called. On systems that 31075 support a ".init" section which is executed at program startup, parts 31076 of `crtstuff.c' are compiled into that section. The program is linked 31077 by the `gcc' driver like this: 31078 31079 ld -o OUTPUT_FILE crti.o crtbegin.o ... -lgcc crtend.o crtn.o 31080 31081 The prologue of a function (`__init') appears in the `.init' section 31082 of `crti.o'; the epilogue appears in `crtn.o'. Likewise for the 31083 function `__fini' in the ".fini" section. Normally these files are 31084 provided by the operating system or by the GNU C library, but are 31085 provided by GCC for a few targets. 31086 31087 The objects `crtbegin.o' and `crtend.o' are (for most targets) 31088 compiled from `crtstuff.c'. They contain, among other things, code 31089 fragments within the `.init' and `.fini' sections that branch to 31090 routines in the `.text' section. The linker will pull all parts of a 31091 section together, which results in a complete `__init' function that 31092 invokes the routines we need at startup. 31093 31094 To use this variant, you must define the `INIT_SECTION_ASM_OP' macro 31095 properly. 31096 31097 If no init section is available, when GCC compiles any function called 31098 `main' (or more accurately, any function designated as a program entry 31099 point by the language front end calling `expand_main_function'), it 31100 inserts a procedure call to `__main' as the first executable code after 31101 the function prologue. The `__main' function is defined in `libgcc2.c' 31102 and runs the global constructors. 31103 31104 In file formats that don't support arbitrary sections, there are again 31105 two variants. In the simplest variant, the GNU linker (GNU `ld') and 31106 an `a.out' format must be used. In this case, `TARGET_ASM_CONSTRUCTOR' 31107 is defined to produce a `.stabs' entry of type `N_SETT', referencing 31108 the name `__CTOR_LIST__', and with the address of the void function 31109 containing the initialization code as its value. The GNU linker 31110 recognizes this as a request to add the value to a "set"; the values 31111 are accumulated, and are eventually placed in the executable as a 31112 vector in the format described above, with a leading (ignored) count 31113 and a trailing zero element. `TARGET_ASM_DESTRUCTOR' is handled 31114 similarly. Since no init section is available, the absence of 31115 `INIT_SECTION_ASM_OP' causes the compilation of `main' to call `__main' 31116 as above, starting the initialization process. 31117 31118 The last variant uses neither arbitrary sections nor the GNU linker. 31119 This is preferable when you want to do dynamic linking and when using 31120 file formats which the GNU linker does not support, such as `ECOFF'. In 31121 this case, `TARGET_HAVE_CTORS_DTORS' is false, initialization and 31122 termination functions are recognized simply by their names. This 31123 requires an extra program in the linkage step, called `collect2'. This 31124 program pretends to be the linker, for use with GCC; it does its job by 31125 running the ordinary linker, but also arranges to include the vectors of 31126 initialization and termination functions. These functions are called 31127 via `__main' as described above. In order to use this method, 31128 `use_collect2' must be defined in the target in `config.gcc'. 31129 31130 The following section describes the specific macros that control and 31131 customize the handling of initialization and termination functions. 31132 31133 31134 File: gccint.info, Node: Macros for Initialization, Next: Instruction Output, Prev: Initialization, Up: Assembler Format 31135 31136 17.21.6 Macros Controlling Initialization Routines 31137 -------------------------------------------------- 31138 31139 Here are the macros that control how the compiler handles initialization 31140 and termination functions: 31141 31142 -- Macro: INIT_SECTION_ASM_OP 31143 If defined, a C string constant, including spacing, for the 31144 assembler operation to identify the following data as 31145 initialization code. If not defined, GCC will assume such a 31146 section does not exist. When you are using special sections for 31147 initialization and termination functions, this macro also controls 31148 how `crtstuff.c' and `libgcc2.c' arrange to run the initialization 31149 functions. 31150 31151 -- Macro: HAS_INIT_SECTION 31152 If defined, `main' will not call `__main' as described above. 31153 This macro should be defined for systems that control start-up code 31154 on a symbol-by-symbol basis, such as OSF/1, and should not be 31155 defined explicitly for systems that support `INIT_SECTION_ASM_OP'. 31156 31157 -- Macro: LD_INIT_SWITCH 31158 If defined, a C string constant for a switch that tells the linker 31159 that the following symbol is an initialization routine. 31160 31161 -- Macro: LD_FINI_SWITCH 31162 If defined, a C string constant for a switch that tells the linker 31163 that the following symbol is a finalization routine. 31164 31165 -- Macro: COLLECT_SHARED_INIT_FUNC (STREAM, FUNC) 31166 If defined, a C statement that will write a function that can be 31167 automatically called when a shared library is loaded. The function 31168 should call FUNC, which takes no arguments. If not defined, and 31169 the object format requires an explicit initialization function, 31170 then a function called `_GLOBAL__DI' will be generated. 31171 31172 This function and the following one are used by collect2 when 31173 linking a shared library that needs constructors or destructors, 31174 or has DWARF2 exception tables embedded in the code. 31175 31176 -- Macro: COLLECT_SHARED_FINI_FUNC (STREAM, FUNC) 31177 If defined, a C statement that will write a function that can be 31178 automatically called when a shared library is unloaded. The 31179 function should call FUNC, which takes no arguments. If not 31180 defined, and the object format requires an explicit finalization 31181 function, then a function called `_GLOBAL__DD' will be generated. 31182 31183 -- Macro: INVOKE__main 31184 If defined, `main' will call `__main' despite the presence of 31185 `INIT_SECTION_ASM_OP'. This macro should be defined for systems 31186 where the init section is not actually run automatically, but is 31187 still useful for collecting the lists of constructors and 31188 destructors. 31189 31190 -- Macro: SUPPORTS_INIT_PRIORITY 31191 If nonzero, the C++ `init_priority' attribute is supported and the 31192 compiler should emit instructions to control the order of 31193 initialization of objects. If zero, the compiler will issue an 31194 error message upon encountering an `init_priority' attribute. 31195 31196 -- Target Hook: bool TARGET_HAVE_CTORS_DTORS 31197 This value is true if the target supports some "native" method of 31198 collecting constructors and destructors to be run at startup and 31199 exit. It is false if we must use `collect2'. 31200 31201 -- Target Hook: void TARGET_ASM_CONSTRUCTOR (rtx SYMBOL, int PRIORITY) 31202 If defined, a function that outputs assembler code to arrange to 31203 call the function referenced by SYMBOL at initialization time. 31204 31205 Assume that SYMBOL is a `SYMBOL_REF' for a function taking no 31206 arguments and with no return value. If the target supports 31207 initialization priorities, PRIORITY is a value between 0 and 31208 `MAX_INIT_PRIORITY'; otherwise it must be `DEFAULT_INIT_PRIORITY'. 31209 31210 If this macro is not defined by the target, a suitable default will 31211 be chosen if (1) the target supports arbitrary section names, (2) 31212 the target defines `CTORS_SECTION_ASM_OP', or (3) `USE_COLLECT2' 31213 is not defined. 31214 31215 -- Target Hook: void TARGET_ASM_DESTRUCTOR (rtx SYMBOL, int PRIORITY) 31216 This is like `TARGET_ASM_CONSTRUCTOR' but used for termination 31217 functions rather than initialization functions. 31218 31219 If `TARGET_HAVE_CTORS_DTORS' is true, the initialization routine 31220 generated for the generated object file will have static linkage. 31221 31222 If your system uses `collect2' as the means of processing 31223 constructors, then that program normally uses `nm' to scan an object 31224 file for constructor functions to be called. 31225 31226 On certain kinds of systems, you can define this macro to make 31227 `collect2' work faster (and, in some cases, make it work at all): 31228 31229 -- Macro: OBJECT_FORMAT_COFF 31230 Define this macro if the system uses COFF (Common Object File 31231 Format) object files, so that `collect2' can assume this format 31232 and scan object files directly for dynamic constructor/destructor 31233 functions. 31234 31235 This macro is effective only in a native compiler; `collect2' as 31236 part of a cross compiler always uses `nm' for the target machine. 31237 31238 -- Macro: REAL_NM_FILE_NAME 31239 Define this macro as a C string constant containing the file name 31240 to use to execute `nm'. The default is to search the path 31241 normally for `nm'. 31242 31243 If your system supports shared libraries and has a program to list 31244 the dynamic dependencies of a given library or executable, you can 31245 define these macros to enable support for running initialization 31246 and termination functions in shared libraries: 31247 31248 -- Macro: LDD_SUFFIX 31249 Define this macro to a C string constant containing the name of 31250 the program which lists dynamic dependencies, like `"ldd"' under 31251 SunOS 4. 31252 31253 -- Macro: PARSE_LDD_OUTPUT (PTR) 31254 Define this macro to be C code that extracts filenames from the 31255 output of the program denoted by `LDD_SUFFIX'. PTR is a variable 31256 of type `char *' that points to the beginning of a line of output 31257 from `LDD_SUFFIX'. If the line lists a dynamic dependency, the 31258 code must advance PTR to the beginning of the filename on that 31259 line. Otherwise, it must set PTR to `NULL'. 31260 31261 -- Macro: SHLIB_SUFFIX 31262 Define this macro to a C string constant containing the default 31263 shared library extension of the target (e.g., `".so"'). `collect2' 31264 strips version information after this suffix when generating global 31265 constructor and destructor names. This define is only needed on 31266 targets that use `collect2' to process constructors and 31267 destructors. 31268 31269 31270 File: gccint.info, Node: Instruction Output, Next: Dispatch Tables, Prev: Macros for Initialization, Up: Assembler Format 31271 31272 17.21.7 Output of Assembler Instructions 31273 ---------------------------------------- 31274 31275 This describes assembler instruction output. 31276 31277 -- Macro: REGISTER_NAMES 31278 A C initializer containing the assembler's names for the machine 31279 registers, each one as a C string constant. This is what 31280 translates register numbers in the compiler into assembler 31281 language. 31282 31283 -- Macro: ADDITIONAL_REGISTER_NAMES 31284 If defined, a C initializer for an array of structures containing 31285 a name and a register number. This macro defines additional names 31286 for hard registers, thus allowing the `asm' option in declarations 31287 to refer to registers using alternate names. 31288 31289 -- Macro: ASM_OUTPUT_OPCODE (STREAM, PTR) 31290 Define this macro if you are using an unusual assembler that 31291 requires different names for the machine instructions. 31292 31293 The definition is a C statement or statements which output an 31294 assembler instruction opcode to the stdio stream STREAM. The 31295 macro-operand PTR is a variable of type `char *' which points to 31296 the opcode name in its "internal" form--the form that is written 31297 in the machine description. The definition should output the 31298 opcode name to STREAM, performing any translation you desire, and 31299 increment the variable PTR to point at the end of the opcode so 31300 that it will not be output twice. 31301 31302 In fact, your macro definition may process less than the entire 31303 opcode name, or more than the opcode name; but if you want to 31304 process text that includes `%'-sequences to substitute operands, 31305 you must take care of the substitution yourself. Just be sure to 31306 increment PTR over whatever text should not be output normally. 31307 31308 If you need to look at the operand values, they can be found as the 31309 elements of `recog_data.operand'. 31310 31311 If the macro definition does nothing, the instruction is output in 31312 the usual way. 31313 31314 -- Macro: FINAL_PRESCAN_INSN (INSN, OPVEC, NOPERANDS) 31315 If defined, a C statement to be executed just prior to the output 31316 of assembler code for INSN, to modify the extracted operands so 31317 they will be output differently. 31318 31319 Here the argument OPVEC is the vector containing the operands 31320 extracted from INSN, and NOPERANDS is the number of elements of 31321 the vector which contain meaningful data for this insn. The 31322 contents of this vector are what will be used to convert the insn 31323 template into assembler code, so you can change the assembler 31324 output by changing the contents of the vector. 31325 31326 This macro is useful when various assembler syntaxes share a single 31327 file of instruction patterns; by defining this macro differently, 31328 you can cause a large class of instructions to be output 31329 differently (such as with rearranged operands). Naturally, 31330 variations in assembler syntax affecting individual insn patterns 31331 ought to be handled by writing conditional output routines in 31332 those patterns. 31333 31334 If this macro is not defined, it is equivalent to a null statement. 31335 31336 -- Macro: PRINT_OPERAND (STREAM, X, CODE) 31337 A C compound statement to output to stdio stream STREAM the 31338 assembler syntax for an instruction operand X. X is an RTL 31339 expression. 31340 31341 CODE is a value that can be used to specify one of several ways of 31342 printing the operand. It is used when identical operands must be 31343 printed differently depending on the context. CODE comes from the 31344 `%' specification that was used to request printing of the 31345 operand. If the specification was just `%DIGIT' then CODE is 0; 31346 if the specification was `%LTR DIGIT' then CODE is the ASCII code 31347 for LTR. 31348 31349 If X is a register, this macro should print the register's name. 31350 The names can be found in an array `reg_names' whose type is `char 31351 *[]'. `reg_names' is initialized from `REGISTER_NAMES'. 31352 31353 When the machine description has a specification `%PUNCT' (a `%' 31354 followed by a punctuation character), this macro is called with a 31355 null pointer for X and the punctuation character for CODE. 31356 31357 -- Macro: PRINT_OPERAND_PUNCT_VALID_P (CODE) 31358 A C expression which evaluates to true if CODE is a valid 31359 punctuation character for use in the `PRINT_OPERAND' macro. If 31360 `PRINT_OPERAND_PUNCT_VALID_P' is not defined, it means that no 31361 punctuation characters (except for the standard one, `%') are used 31362 in this way. 31363 31364 -- Macro: PRINT_OPERAND_ADDRESS (STREAM, X) 31365 A C compound statement to output to stdio stream STREAM the 31366 assembler syntax for an instruction operand that is a memory 31367 reference whose address is X. X is an RTL expression. 31368 31369 On some machines, the syntax for a symbolic address depends on the 31370 section that the address refers to. On these machines, define the 31371 hook `TARGET_ENCODE_SECTION_INFO' to store the information into the 31372 `symbol_ref', and then check for it here. *Note Assembler 31373 Format::. 31374 31375 -- Macro: DBR_OUTPUT_SEQEND (FILE) 31376 A C statement, to be executed after all slot-filler instructions 31377 have been output. If necessary, call `dbr_sequence_length' to 31378 determine the number of slots filled in a sequence (zero if not 31379 currently outputting a sequence), to decide how many no-ops to 31380 output, or whatever. 31381 31382 Don't define this macro if it has nothing to do, but it is helpful 31383 in reading assembly output if the extent of the delay sequence is 31384 made explicit (e.g. with white space). 31385 31386 Note that output routines for instructions with delay slots must be 31387 prepared to deal with not being output as part of a sequence (i.e. when 31388 the scheduling pass is not run, or when no slot fillers could be 31389 found.) The variable `final_sequence' is null when not processing a 31390 sequence, otherwise it contains the `sequence' rtx being output. 31391 31392 -- Macro: REGISTER_PREFIX 31393 -- Macro: LOCAL_LABEL_PREFIX 31394 -- Macro: USER_LABEL_PREFIX 31395 -- Macro: IMMEDIATE_PREFIX 31396 If defined, C string expressions to be used for the `%R', `%L', 31397 `%U', and `%I' options of `asm_fprintf' (see `final.c'). These 31398 are useful when a single `md' file must support multiple assembler 31399 formats. In that case, the various `tm.h' files can define these 31400 macros differently. 31401 31402 -- Macro: ASM_FPRINTF_EXTENSIONS (FILE, ARGPTR, FORMAT) 31403 If defined this macro should expand to a series of `case' 31404 statements which will be parsed inside the `switch' statement of 31405 the `asm_fprintf' function. This allows targets to define extra 31406 printf formats which may useful when generating their assembler 31407 statements. Note that uppercase letters are reserved for future 31408 generic extensions to asm_fprintf, and so are not available to 31409 target specific code. The output file is given by the parameter 31410 FILE. The varargs input pointer is ARGPTR and the rest of the 31411 format string, starting the character after the one that is being 31412 switched upon, is pointed to by FORMAT. 31413 31414 -- Macro: ASSEMBLER_DIALECT 31415 If your target supports multiple dialects of assembler language 31416 (such as different opcodes), define this macro as a C expression 31417 that gives the numeric index of the assembler language dialect to 31418 use, with zero as the first variant. 31419 31420 If this macro is defined, you may use constructs of the form 31421 `{option0|option1|option2...}' 31422 in the output templates of patterns (*note Output Template::) or 31423 in the first argument of `asm_fprintf'. This construct outputs 31424 `option0', `option1', `option2', etc., if the value of 31425 `ASSEMBLER_DIALECT' is zero, one, two, etc. Any special characters 31426 within these strings retain their usual meaning. If there are 31427 fewer alternatives within the braces than the value of 31428 `ASSEMBLER_DIALECT', the construct outputs nothing. 31429 31430 If you do not define this macro, the characters `{', `|' and `}' 31431 do not have any special meaning when used in templates or operands 31432 to `asm_fprintf'. 31433 31434 Define the macros `REGISTER_PREFIX', `LOCAL_LABEL_PREFIX', 31435 `USER_LABEL_PREFIX' and `IMMEDIATE_PREFIX' if you can express the 31436 variations in assembler language syntax with that mechanism. 31437 Define `ASSEMBLER_DIALECT' and use the `{option0|option1}' syntax 31438 if the syntax variant are larger and involve such things as 31439 different opcodes or operand order. 31440 31441 -- Macro: ASM_OUTPUT_REG_PUSH (STREAM, REGNO) 31442 A C expression to output to STREAM some assembler code which will 31443 push hard register number REGNO onto the stack. The code need not 31444 be optimal, since this macro is used only when profiling. 31445 31446 -- Macro: ASM_OUTPUT_REG_POP (STREAM, REGNO) 31447 A C expression to output to STREAM some assembler code which will 31448 pop hard register number REGNO off of the stack. The code need 31449 not be optimal, since this macro is used only when profiling. 31450 31451 31452 File: gccint.info, Node: Dispatch Tables, Next: Exception Region Output, Prev: Instruction Output, Up: Assembler Format 31453 31454 17.21.8 Output of Dispatch Tables 31455 --------------------------------- 31456 31457 This concerns dispatch tables. 31458 31459 -- Macro: ASM_OUTPUT_ADDR_DIFF_ELT (STREAM, BODY, VALUE, REL) 31460 A C statement to output to the stdio stream STREAM an assembler 31461 pseudo-instruction to generate a difference between two labels. 31462 VALUE and REL are the numbers of two internal labels. The 31463 definitions of these labels are output using 31464 `(*targetm.asm_out.internal_label)', and they must be printed in 31465 the same way here. For example, 31466 31467 fprintf (STREAM, "\t.word L%d-L%d\n", 31468 VALUE, REL) 31469 31470 You must provide this macro on machines where the addresses in a 31471 dispatch table are relative to the table's own address. If 31472 defined, GCC will also use this macro on all machines when 31473 producing PIC. BODY is the body of the `ADDR_DIFF_VEC'; it is 31474 provided so that the mode and flags can be read. 31475 31476 -- Macro: ASM_OUTPUT_ADDR_VEC_ELT (STREAM, VALUE) 31477 This macro should be provided on machines where the addresses in a 31478 dispatch table are absolute. 31479 31480 The definition should be a C statement to output to the stdio 31481 stream STREAM an assembler pseudo-instruction to generate a 31482 reference to a label. VALUE is the number of an internal label 31483 whose definition is output using 31484 `(*targetm.asm_out.internal_label)'. For example, 31485 31486 fprintf (STREAM, "\t.word L%d\n", VALUE) 31487 31488 -- Macro: ASM_OUTPUT_CASE_LABEL (STREAM, PREFIX, NUM, TABLE) 31489 Define this if the label before a jump-table needs to be output 31490 specially. The first three arguments are the same as for 31491 `(*targetm.asm_out.internal_label)'; the fourth argument is the 31492 jump-table which follows (a `jump_insn' containing an `addr_vec' 31493 or `addr_diff_vec'). 31494 31495 This feature is used on system V to output a `swbeg' statement for 31496 the table. 31497 31498 If this macro is not defined, these labels are output with 31499 `(*targetm.asm_out.internal_label)'. 31500 31501 -- Macro: ASM_OUTPUT_CASE_END (STREAM, NUM, TABLE) 31502 Define this if something special must be output at the end of a 31503 jump-table. The definition should be a C statement to be executed 31504 after the assembler code for the table is written. It should write 31505 the appropriate code to stdio stream STREAM. The argument TABLE 31506 is the jump-table insn, and NUM is the label-number of the 31507 preceding label. 31508 31509 If this macro is not defined, nothing special is output at the end 31510 of the jump-table. 31511 31512 -- Target Hook: void TARGET_ASM_EMIT_UNWIND_LABEL (STREAM, DECL, 31513 FOR_EH, EMPTY) 31514 This target hook emits a label at the beginning of each FDE. It 31515 should be defined on targets where FDEs need special labels, and it 31516 should write the appropriate label, for the FDE associated with the 31517 function declaration DECL, to the stdio stream STREAM. The third 31518 argument, FOR_EH, is a boolean: true if this is for an exception 31519 table. The fourth argument, EMPTY, is a boolean: true if this is 31520 a placeholder label for an omitted FDE. 31521 31522 The default is that FDEs are not given nonlocal labels. 31523 31524 -- Target Hook: void TARGET_ASM_EMIT_EXCEPT_TABLE_LABEL (STREAM) 31525 This target hook emits a label at the beginning of the exception 31526 table. It should be defined on targets where it is desirable for 31527 the table to be broken up according to function. 31528 31529 The default is that no label is emitted. 31530 31531 -- Target Hook: void TARGET_UNWIND_EMIT (FILE * STREAM, rtx INSN) 31532 This target hook emits and assembly directives required to unwind 31533 the given instruction. This is only used when TARGET_UNWIND_INFO 31534 is set. 31535 31536 31537 File: gccint.info, Node: Exception Region Output, Next: Alignment Output, Prev: Dispatch Tables, Up: Assembler Format 31538 31539 17.21.9 Assembler Commands for Exception Regions 31540 ------------------------------------------------ 31541 31542 This describes commands marking the start and the end of an exception 31543 region. 31544 31545 -- Macro: EH_FRAME_SECTION_NAME 31546 If defined, a C string constant for the name of the section 31547 containing exception handling frame unwind information. If not 31548 defined, GCC will provide a default definition if the target 31549 supports named sections. `crtstuff.c' uses this macro to switch 31550 to the appropriate section. 31551 31552 You should define this symbol if your target supports DWARF 2 frame 31553 unwind information and the default definition does not work. 31554 31555 -- Macro: EH_FRAME_IN_DATA_SECTION 31556 If defined, DWARF 2 frame unwind information will be placed in the 31557 data section even though the target supports named sections. This 31558 might be necessary, for instance, if the system linker does garbage 31559 collection and sections cannot be marked as not to be collected. 31560 31561 Do not define this macro unless `TARGET_ASM_NAMED_SECTION' is also 31562 defined. 31563 31564 -- Macro: EH_TABLES_CAN_BE_READ_ONLY 31565 Define this macro to 1 if your target is such that no frame unwind 31566 information encoding used with non-PIC code will ever require a 31567 runtime relocation, but the linker may not support merging 31568 read-only and read-write sections into a single read-write section. 31569 31570 -- Macro: MASK_RETURN_ADDR 31571 An rtx used to mask the return address found via 31572 `RETURN_ADDR_RTX', so that it does not contain any extraneous set 31573 bits in it. 31574 31575 -- Macro: DWARF2_UNWIND_INFO 31576 Define this macro to 0 if your target supports DWARF 2 frame unwind 31577 information, but it does not yet work with exception handling. 31578 Otherwise, if your target supports this information (if it defines 31579 `INCOMING_RETURN_ADDR_RTX' and either `UNALIGNED_INT_ASM_OP' or 31580 `OBJECT_FORMAT_ELF'), GCC will provide a default definition of 1. 31581 31582 If `TARGET_UNWIND_INFO' is defined, the target specific unwinder 31583 will be used in all cases. Defining this macro will enable the 31584 generation of DWARF 2 frame debugging information. 31585 31586 If `TARGET_UNWIND_INFO' is not defined, and this macro is defined 31587 to 1, the DWARF 2 unwinder will be the default exception handling 31588 mechanism; otherwise, the `setjmp'/`longjmp'-based scheme will be 31589 used by default. 31590 31591 -- Macro: TARGET_UNWIND_INFO 31592 Define this macro if your target has ABI specified unwind tables. 31593 Usually these will be output by `TARGET_UNWIND_EMIT'. 31594 31595 -- Variable: Target Hook bool TARGET_UNWIND_TABLES_DEFAULT 31596 This variable should be set to `true' if the target ABI requires 31597 unwinding tables even when exceptions are not used. 31598 31599 -- Macro: MUST_USE_SJLJ_EXCEPTIONS 31600 This macro need only be defined if `DWARF2_UNWIND_INFO' is 31601 runtime-variable. In that case, `except.h' cannot correctly 31602 determine the corresponding definition of 31603 `MUST_USE_SJLJ_EXCEPTIONS', so the target must provide it directly. 31604 31605 -- Macro: DONT_USE_BUILTIN_SETJMP 31606 Define this macro to 1 if the `setjmp'/`longjmp'-based scheme 31607 should use the `setjmp'/`longjmp' functions from the C library 31608 instead of the `__builtin_setjmp'/`__builtin_longjmp' machinery. 31609 31610 -- Macro: DWARF_CIE_DATA_ALIGNMENT 31611 This macro need only be defined if the target might save registers 31612 in the function prologue at an offset to the stack pointer that is 31613 not aligned to `UNITS_PER_WORD'. The definition should be the 31614 negative minimum alignment if `STACK_GROWS_DOWNWARD' is defined, 31615 and the positive minimum alignment otherwise. *Note SDB and 31616 DWARF::. Only applicable if the target supports DWARF 2 frame 31617 unwind information. 31618 31619 -- Variable: Target Hook bool TARGET_TERMINATE_DW2_EH_FRAME_INFO 31620 Contains the value true if the target should add a zero word onto 31621 the end of a Dwarf-2 frame info section when used for exception 31622 handling. Default value is false if `EH_FRAME_SECTION_NAME' is 31623 defined, and true otherwise. 31624 31625 -- Target Hook: rtx TARGET_DWARF_REGISTER_SPAN (rtx REG) 31626 Given a register, this hook should return a parallel of registers 31627 to represent where to find the register pieces. Define this hook 31628 if the register and its mode are represented in Dwarf in 31629 non-contiguous locations, or if the register should be represented 31630 in more than one register in Dwarf. Otherwise, this hook should 31631 return `NULL_RTX'. If not defined, the default is to return 31632 `NULL_RTX'. 31633 31634 -- Target Hook: void TARGET_INIT_DWARF_REG_SIZES_EXTRA (tree ADDRESS) 31635 If some registers are represented in Dwarf-2 unwind information in 31636 multiple pieces, define this hook to fill in information about the 31637 sizes of those pieces in the table used by the unwinder at runtime. 31638 It will be called by `expand_builtin_init_dwarf_reg_sizes' after 31639 filling in a single size corresponding to each hard register; 31640 ADDRESS is the address of the table. 31641 31642 -- Target Hook: bool TARGET_ASM_TTYPE (rtx SYM) 31643 This hook is used to output a reference from a frame unwinding 31644 table to the type_info object identified by SYM. It should return 31645 `true' if the reference was output. Returning `false' will cause 31646 the reference to be output using the normal Dwarf2 routines. 31647 31648 -- Target Hook: bool TARGET_ARM_EABI_UNWINDER 31649 This hook should be set to `true' on targets that use an ARM EABI 31650 based unwinding library, and `false' on other targets. This 31651 effects the format of unwinding tables, and how the unwinder in 31652 entered after running a cleanup. The default is `false'. 31653 31654 31655 File: gccint.info, Node: Alignment Output, Prev: Exception Region Output, Up: Assembler Format 31656 31657 17.21.10 Assembler Commands for Alignment 31658 ----------------------------------------- 31659 31660 This describes commands for alignment. 31661 31662 -- Macro: JUMP_ALIGN (LABEL) 31663 The alignment (log base 2) to put in front of LABEL, which is a 31664 common destination of jumps and has no fallthru incoming edge. 31665 31666 This macro need not be defined if you don't want any special 31667 alignment to be done at such a time. Most machine descriptions do 31668 not currently define the macro. 31669 31670 Unless it's necessary to inspect the LABEL parameter, it is better 31671 to set the variable ALIGN_JUMPS in the target's 31672 `OVERRIDE_OPTIONS'. Otherwise, you should try to honor the user's 31673 selection in ALIGN_JUMPS in a `JUMP_ALIGN' implementation. 31674 31675 -- Macro: LABEL_ALIGN_AFTER_BARRIER (LABEL) 31676 The alignment (log base 2) to put in front of LABEL, which follows 31677 a `BARRIER'. 31678 31679 This macro need not be defined if you don't want any special 31680 alignment to be done at such a time. Most machine descriptions do 31681 not currently define the macro. 31682 31683 -- Macro: LABEL_ALIGN_AFTER_BARRIER_MAX_SKIP 31684 The maximum number of bytes to skip when applying 31685 `LABEL_ALIGN_AFTER_BARRIER'. This works only if 31686 `ASM_OUTPUT_MAX_SKIP_ALIGN' is defined. 31687 31688 -- Macro: LOOP_ALIGN (LABEL) 31689 The alignment (log base 2) to put in front of LABEL, which follows 31690 a `NOTE_INSN_LOOP_BEG' note. 31691 31692 This macro need not be defined if you don't want any special 31693 alignment to be done at such a time. Most machine descriptions do 31694 not currently define the macro. 31695 31696 Unless it's necessary to inspect the LABEL parameter, it is better 31697 to set the variable `align_loops' in the target's 31698 `OVERRIDE_OPTIONS'. Otherwise, you should try to honor the user's 31699 selection in `align_loops' in a `LOOP_ALIGN' implementation. 31700 31701 -- Macro: LOOP_ALIGN_MAX_SKIP 31702 The maximum number of bytes to skip when applying `LOOP_ALIGN'. 31703 This works only if `ASM_OUTPUT_MAX_SKIP_ALIGN' is defined. 31704 31705 -- Macro: LABEL_ALIGN (LABEL) 31706 The alignment (log base 2) to put in front of LABEL. If 31707 `LABEL_ALIGN_AFTER_BARRIER' / `LOOP_ALIGN' specify a different 31708 alignment, the maximum of the specified values is used. 31709 31710 Unless it's necessary to inspect the LABEL parameter, it is better 31711 to set the variable `align_labels' in the target's 31712 `OVERRIDE_OPTIONS'. Otherwise, you should try to honor the user's 31713 selection in `align_labels' in a `LABEL_ALIGN' implementation. 31714 31715 -- Macro: LABEL_ALIGN_MAX_SKIP 31716 The maximum number of bytes to skip when applying `LABEL_ALIGN'. 31717 This works only if `ASM_OUTPUT_MAX_SKIP_ALIGN' is defined. 31718 31719 -- Macro: ASM_OUTPUT_SKIP (STREAM, NBYTES) 31720 A C statement to output to the stdio stream STREAM an assembler 31721 instruction to advance the location counter by NBYTES bytes. 31722 Those bytes should be zero when loaded. NBYTES will be a C 31723 expression of type `unsigned HOST_WIDE_INT'. 31724 31725 -- Macro: ASM_NO_SKIP_IN_TEXT 31726 Define this macro if `ASM_OUTPUT_SKIP' should not be used in the 31727 text section because it fails to put zeros in the bytes that are 31728 skipped. This is true on many Unix systems, where the pseudo-op 31729 to skip bytes produces no-op instructions rather than zeros when 31730 used in the text section. 31731 31732 -- Macro: ASM_OUTPUT_ALIGN (STREAM, POWER) 31733 A C statement to output to the stdio stream STREAM an assembler 31734 command to advance the location counter to a multiple of 2 to the 31735 POWER bytes. POWER will be a C expression of type `int'. 31736 31737 -- Macro: ASM_OUTPUT_ALIGN_WITH_NOP (STREAM, POWER) 31738 Like `ASM_OUTPUT_ALIGN', except that the "nop" instruction is used 31739 for padding, if necessary. 31740 31741 -- Macro: ASM_OUTPUT_MAX_SKIP_ALIGN (STREAM, POWER, MAX_SKIP) 31742 A C statement to output to the stdio stream STREAM an assembler 31743 command to advance the location counter to a multiple of 2 to the 31744 POWER bytes, but only if MAX_SKIP or fewer bytes are needed to 31745 satisfy the alignment request. POWER and MAX_SKIP will be a C 31746 expression of type `int'. 31747 31748 31749 File: gccint.info, Node: Debugging Info, Next: Floating Point, Prev: Assembler Format, Up: Target Macros 31750 31751 17.22 Controlling Debugging Information Format 31752 ============================================== 31753 31754 This describes how to specify debugging information. 31755 31756 * Menu: 31757 31758 * All Debuggers:: Macros that affect all debugging formats uniformly. 31759 * DBX Options:: Macros enabling specific options in DBX format. 31760 * DBX Hooks:: Hook macros for varying DBX format. 31761 * File Names and DBX:: Macros controlling output of file names in DBX format. 31762 * SDB and DWARF:: Macros for SDB (COFF) and DWARF formats. 31763 * VMS Debug:: Macros for VMS debug format. 31764 31765 31766 File: gccint.info, Node: All Debuggers, Next: DBX Options, Up: Debugging Info 31767 31768 17.22.1 Macros Affecting All Debugging Formats 31769 ---------------------------------------------- 31770 31771 These macros affect all debugging formats. 31772 31773 -- Macro: DBX_REGISTER_NUMBER (REGNO) 31774 A C expression that returns the DBX register number for the 31775 compiler register number REGNO. In the default macro provided, 31776 the value of this expression will be REGNO itself. But sometimes 31777 there are some registers that the compiler knows about and DBX 31778 does not, or vice versa. In such cases, some register may need to 31779 have one number in the compiler and another for DBX. 31780 31781 If two registers have consecutive numbers inside GCC, and they can 31782 be used as a pair to hold a multiword value, then they _must_ have 31783 consecutive numbers after renumbering with `DBX_REGISTER_NUMBER'. 31784 Otherwise, debuggers will be unable to access such a pair, because 31785 they expect register pairs to be consecutive in their own 31786 numbering scheme. 31787 31788 If you find yourself defining `DBX_REGISTER_NUMBER' in way that 31789 does not preserve register pairs, then what you must do instead is 31790 redefine the actual register numbering scheme. 31791 31792 -- Macro: DEBUGGER_AUTO_OFFSET (X) 31793 A C expression that returns the integer offset value for an 31794 automatic variable having address X (an RTL expression). The 31795 default computation assumes that X is based on the frame-pointer 31796 and gives the offset from the frame-pointer. This is required for 31797 targets that produce debugging output for DBX or COFF-style 31798 debugging output for SDB and allow the frame-pointer to be 31799 eliminated when the `-g' options is used. 31800 31801 -- Macro: DEBUGGER_ARG_OFFSET (OFFSET, X) 31802 A C expression that returns the integer offset value for an 31803 argument having address X (an RTL expression). The nominal offset 31804 is OFFSET. 31805 31806 -- Macro: PREFERRED_DEBUGGING_TYPE 31807 A C expression that returns the type of debugging output GCC should 31808 produce when the user specifies just `-g'. Define this if you 31809 have arranged for GCC to support more than one format of debugging 31810 output. Currently, the allowable values are `DBX_DEBUG', 31811 `SDB_DEBUG', `DWARF_DEBUG', `DWARF2_DEBUG', `XCOFF_DEBUG', 31812 `VMS_DEBUG', and `VMS_AND_DWARF2_DEBUG'. 31813 31814 When the user specifies `-ggdb', GCC normally also uses the value 31815 of this macro to select the debugging output format, but with two 31816 exceptions. If `DWARF2_DEBUGGING_INFO' is defined, GCC uses the 31817 value `DWARF2_DEBUG'. Otherwise, if `DBX_DEBUGGING_INFO' is 31818 defined, GCC uses `DBX_DEBUG'. 31819 31820 The value of this macro only affects the default debugging output; 31821 the user can always get a specific type of output by using 31822 `-gstabs', `-gcoff', `-gdwarf-2', `-gxcoff', or `-gvms'. 31823 31824 31825 File: gccint.info, Node: DBX Options, Next: DBX Hooks, Prev: All Debuggers, Up: Debugging Info 31826 31827 17.22.2 Specific Options for DBX Output 31828 --------------------------------------- 31829 31830 These are specific options for DBX output. 31831 31832 -- Macro: DBX_DEBUGGING_INFO 31833 Define this macro if GCC should produce debugging output for DBX 31834 in response to the `-g' option. 31835 31836 -- Macro: XCOFF_DEBUGGING_INFO 31837 Define this macro if GCC should produce XCOFF format debugging 31838 output in response to the `-g' option. This is a variant of DBX 31839 format. 31840 31841 -- Macro: DEFAULT_GDB_EXTENSIONS 31842 Define this macro to control whether GCC should by default generate 31843 GDB's extended version of DBX debugging information (assuming 31844 DBX-format debugging information is enabled at all). If you don't 31845 define the macro, the default is 1: always generate the extended 31846 information if there is any occasion to. 31847 31848 -- Macro: DEBUG_SYMS_TEXT 31849 Define this macro if all `.stabs' commands should be output while 31850 in the text section. 31851 31852 -- Macro: ASM_STABS_OP 31853 A C string constant, including spacing, naming the assembler 31854 pseudo op to use instead of `"\t.stabs\t"' to define an ordinary 31855 debugging symbol. If you don't define this macro, `"\t.stabs\t"' 31856 is used. This macro applies only to DBX debugging information 31857 format. 31858 31859 -- Macro: ASM_STABD_OP 31860 A C string constant, including spacing, naming the assembler 31861 pseudo op to use instead of `"\t.stabd\t"' to define a debugging 31862 symbol whose value is the current location. If you don't define 31863 this macro, `"\t.stabd\t"' is used. This macro applies only to 31864 DBX debugging information format. 31865 31866 -- Macro: ASM_STABN_OP 31867 A C string constant, including spacing, naming the assembler 31868 pseudo op to use instead of `"\t.stabn\t"' to define a debugging 31869 symbol with no name. If you don't define this macro, 31870 `"\t.stabn\t"' is used. This macro applies only to DBX debugging 31871 information format. 31872 31873 -- Macro: DBX_NO_XREFS 31874 Define this macro if DBX on your system does not support the 31875 construct `xsTAGNAME'. On some systems, this construct is used to 31876 describe a forward reference to a structure named TAGNAME. On 31877 other systems, this construct is not supported at all. 31878 31879 -- Macro: DBX_CONTIN_LENGTH 31880 A symbol name in DBX-format debugging information is normally 31881 continued (split into two separate `.stabs' directives) when it 31882 exceeds a certain length (by default, 80 characters). On some 31883 operating systems, DBX requires this splitting; on others, 31884 splitting must not be done. You can inhibit splitting by defining 31885 this macro with the value zero. You can override the default 31886 splitting-length by defining this macro as an expression for the 31887 length you desire. 31888 31889 -- Macro: DBX_CONTIN_CHAR 31890 Normally continuation is indicated by adding a `\' character to 31891 the end of a `.stabs' string when a continuation follows. To use 31892 a different character instead, define this macro as a character 31893 constant for the character you want to use. Do not define this 31894 macro if backslash is correct for your system. 31895 31896 -- Macro: DBX_STATIC_STAB_DATA_SECTION 31897 Define this macro if it is necessary to go to the data section 31898 before outputting the `.stabs' pseudo-op for a non-global static 31899 variable. 31900 31901 -- Macro: DBX_TYPE_DECL_STABS_CODE 31902 The value to use in the "code" field of the `.stabs' directive for 31903 a typedef. The default is `N_LSYM'. 31904 31905 -- Macro: DBX_STATIC_CONST_VAR_CODE 31906 The value to use in the "code" field of the `.stabs' directive for 31907 a static variable located in the text section. DBX format does not 31908 provide any "right" way to do this. The default is `N_FUN'. 31909 31910 -- Macro: DBX_REGPARM_STABS_CODE 31911 The value to use in the "code" field of the `.stabs' directive for 31912 a parameter passed in registers. DBX format does not provide any 31913 "right" way to do this. The default is `N_RSYM'. 31914 31915 -- Macro: DBX_REGPARM_STABS_LETTER 31916 The letter to use in DBX symbol data to identify a symbol as a 31917 parameter passed in registers. DBX format does not customarily 31918 provide any way to do this. The default is `'P''. 31919 31920 -- Macro: DBX_FUNCTION_FIRST 31921 Define this macro if the DBX information for a function and its 31922 arguments should precede the assembler code for the function. 31923 Normally, in DBX format, the debugging information entirely 31924 follows the assembler code. 31925 31926 -- Macro: DBX_BLOCKS_FUNCTION_RELATIVE 31927 Define this macro, with value 1, if the value of a symbol 31928 describing the scope of a block (`N_LBRAC' or `N_RBRAC') should be 31929 relative to the start of the enclosing function. Normally, GCC 31930 uses an absolute address. 31931 31932 -- Macro: DBX_LINES_FUNCTION_RELATIVE 31933 Define this macro, with value 1, if the value of a symbol 31934 indicating the current line number (`N_SLINE') should be relative 31935 to the start of the enclosing function. Normally, GCC uses an 31936 absolute address. 31937 31938 -- Macro: DBX_USE_BINCL 31939 Define this macro if GCC should generate `N_BINCL' and `N_EINCL' 31940 stabs for included header files, as on Sun systems. This macro 31941 also directs GCC to output a type number as a pair of a file 31942 number and a type number within the file. Normally, GCC does not 31943 generate `N_BINCL' or `N_EINCL' stabs, and it outputs a single 31944 number for a type number. 31945 31946 31947 File: gccint.info, Node: DBX Hooks, Next: File Names and DBX, Prev: DBX Options, Up: Debugging Info 31948 31949 17.22.3 Open-Ended Hooks for DBX Format 31950 --------------------------------------- 31951 31952 These are hooks for DBX format. 31953 31954 -- Macro: DBX_OUTPUT_LBRAC (STREAM, NAME) 31955 Define this macro to say how to output to STREAM the debugging 31956 information for the start of a scope level for variable names. The 31957 argument NAME is the name of an assembler symbol (for use with 31958 `assemble_name') whose value is the address where the scope begins. 31959 31960 -- Macro: DBX_OUTPUT_RBRAC (STREAM, NAME) 31961 Like `DBX_OUTPUT_LBRAC', but for the end of a scope level. 31962 31963 -- Macro: DBX_OUTPUT_NFUN (STREAM, LSCOPE_LABEL, DECL) 31964 Define this macro if the target machine requires special handling 31965 to output an `N_FUN' entry for the function DECL. 31966 31967 -- Macro: DBX_OUTPUT_SOURCE_LINE (STREAM, LINE, COUNTER) 31968 A C statement to output DBX debugging information before code for 31969 line number LINE of the current source file to the stdio stream 31970 STREAM. COUNTER is the number of time the macro was invoked, 31971 including the current invocation; it is intended to generate 31972 unique labels in the assembly output. 31973 31974 This macro should not be defined if the default output is correct, 31975 or if it can be made correct by defining 31976 `DBX_LINES_FUNCTION_RELATIVE'. 31977 31978 -- Macro: NO_DBX_FUNCTION_END 31979 Some stabs encapsulation formats (in particular ECOFF), cannot 31980 handle the `.stabs "",N_FUN,,0,0,Lscope-function-1' gdb dbx 31981 extension construct. On those machines, define this macro to turn 31982 this feature off without disturbing the rest of the gdb extensions. 31983 31984 -- Macro: NO_DBX_BNSYM_ENSYM 31985 Some assemblers cannot handle the `.stabd BNSYM/ENSYM,0,0' gdb dbx 31986 extension construct. On those machines, define this macro to turn 31987 this feature off without disturbing the rest of the gdb extensions. 31988 31989 31990 File: gccint.info, Node: File Names and DBX, Next: SDB and DWARF, Prev: DBX Hooks, Up: Debugging Info 31991 31992 17.22.4 File Names in DBX Format 31993 -------------------------------- 31994 31995 This describes file names in DBX format. 31996 31997 -- Macro: DBX_OUTPUT_MAIN_SOURCE_FILENAME (STREAM, NAME) 31998 A C statement to output DBX debugging information to the stdio 31999 stream STREAM, which indicates that file NAME is the main source 32000 file--the file specified as the input file for compilation. This 32001 macro is called only once, at the beginning of compilation. 32002 32003 This macro need not be defined if the standard form of output for 32004 DBX debugging information is appropriate. 32005 32006 It may be necessary to refer to a label equal to the beginning of 32007 the text section. You can use `assemble_name (stream, 32008 ltext_label_name)' to do so. If you do this, you must also set 32009 the variable USED_LTEXT_LABEL_NAME to `true'. 32010 32011 -- Macro: NO_DBX_MAIN_SOURCE_DIRECTORY 32012 Define this macro, with value 1, if GCC should not emit an 32013 indication of the current directory for compilation and current 32014 source language at the beginning of the file. 32015 32016 -- Macro: NO_DBX_GCC_MARKER 32017 Define this macro, with value 1, if GCC should not emit an 32018 indication that this object file was compiled by GCC. The default 32019 is to emit an `N_OPT' stab at the beginning of every source file, 32020 with `gcc2_compiled.' for the string and value 0. 32021 32022 -- Macro: DBX_OUTPUT_MAIN_SOURCE_FILE_END (STREAM, NAME) 32023 A C statement to output DBX debugging information at the end of 32024 compilation of the main source file NAME. Output should be 32025 written to the stdio stream STREAM. 32026 32027 If you don't define this macro, nothing special is output at the 32028 end of compilation, which is correct for most machines. 32029 32030 -- Macro: DBX_OUTPUT_NULL_N_SO_AT_MAIN_SOURCE_FILE_END 32031 Define this macro _instead of_ defining 32032 `DBX_OUTPUT_MAIN_SOURCE_FILE_END', if what needs to be output at 32033 the end of compilation is a `N_SO' stab with an empty string, 32034 whose value is the highest absolute text address in the file. 32035 32036 32037 File: gccint.info, Node: SDB and DWARF, Next: VMS Debug, Prev: File Names and DBX, Up: Debugging Info 32038 32039 17.22.5 Macros for SDB and DWARF Output 32040 --------------------------------------- 32041 32042 Here are macros for SDB and DWARF output. 32043 32044 -- Macro: SDB_DEBUGGING_INFO 32045 Define this macro if GCC should produce COFF-style debugging output 32046 for SDB in response to the `-g' option. 32047 32048 -- Macro: DWARF2_DEBUGGING_INFO 32049 Define this macro if GCC should produce dwarf version 2 format 32050 debugging output in response to the `-g' option. 32051 32052 -- Target Hook: int TARGET_DWARF_CALLING_CONVENTION (tree 32053 FUNCTION) 32054 Define this to enable the dwarf attribute 32055 `DW_AT_calling_convention' to be emitted for each function. 32056 Instead of an integer return the enum value for the `DW_CC_' 32057 tag. 32058 32059 To support optional call frame debugging information, you must also 32060 define `INCOMING_RETURN_ADDR_RTX' and either set 32061 `RTX_FRAME_RELATED_P' on the prologue insns if you use RTL for the 32062 prologue, or call `dwarf2out_def_cfa' and `dwarf2out_reg_save' as 32063 appropriate from `TARGET_ASM_FUNCTION_PROLOGUE' if you don't. 32064 32065 -- Macro: DWARF2_FRAME_INFO 32066 Define this macro to a nonzero value if GCC should always output 32067 Dwarf 2 frame information. If `DWARF2_UNWIND_INFO' (*note 32068 Exception Region Output:: is nonzero, GCC will output this 32069 information not matter how you define `DWARF2_FRAME_INFO'. 32070 32071 -- Macro: DWARF2_ASM_LINE_DEBUG_INFO 32072 Define this macro to be a nonzero value if the assembler can 32073 generate Dwarf 2 line debug info sections. This will result in 32074 much more compact line number tables, and hence is desirable if it 32075 works. 32076 32077 -- Macro: ASM_OUTPUT_DWARF_DELTA (STREAM, SIZE, LABEL1, LABEL2) 32078 A C statement to issue assembly directives that create a difference 32079 LAB1 minus LAB2, using an integer of the given SIZE. 32080 32081 -- Macro: ASM_OUTPUT_DWARF_OFFSET (STREAM, SIZE, LABEL, SECTION) 32082 A C statement to issue assembly directives that create a 32083 section-relative reference to the given LABEL, using an integer of 32084 the given SIZE. The label is known to be defined in the given 32085 SECTION. 32086 32087 -- Macro: ASM_OUTPUT_DWARF_PCREL (STREAM, SIZE, LABEL) 32088 A C statement to issue assembly directives that create a 32089 self-relative reference to the given LABEL, using an integer of 32090 the given SIZE. 32091 32092 -- Target Hook: void TARGET_ASM_OUTPUT_DWARF_DTPREL (FILE *FILE, int 32093 SIZE, rtx X) 32094 If defined, this target hook is a function which outputs a 32095 DTP-relative reference to the given TLS symbol of the specified 32096 size. 32097 32098 -- Macro: PUT_SDB_... 32099 Define these macros to override the assembler syntax for the 32100 special SDB assembler directives. See `sdbout.c' for a list of 32101 these macros and their arguments. If the standard syntax is used, 32102 you need not define them yourself. 32103 32104 -- Macro: SDB_DELIM 32105 Some assemblers do not support a semicolon as a delimiter, even 32106 between SDB assembler directives. In that case, define this macro 32107 to be the delimiter to use (usually `\n'). It is not necessary to 32108 define a new set of `PUT_SDB_OP' macros if this is the only change 32109 required. 32110 32111 -- Macro: SDB_ALLOW_UNKNOWN_REFERENCES 32112 Define this macro to allow references to unknown structure, union, 32113 or enumeration tags to be emitted. Standard COFF does not allow 32114 handling of unknown references, MIPS ECOFF has support for it. 32115 32116 -- Macro: SDB_ALLOW_FORWARD_REFERENCES 32117 Define this macro to allow references to structure, union, or 32118 enumeration tags that have not yet been seen to be handled. Some 32119 assemblers choke if forward tags are used, while some require it. 32120 32121 -- Macro: SDB_OUTPUT_SOURCE_LINE (STREAM, LINE) 32122 A C statement to output SDB debugging information before code for 32123 line number LINE of the current source file to the stdio stream 32124 STREAM. The default is to emit an `.ln' directive. 32125 32126 32127 File: gccint.info, Node: VMS Debug, Prev: SDB and DWARF, Up: Debugging Info 32128 32129 17.22.6 Macros for VMS Debug Format 32130 ----------------------------------- 32131 32132 Here are macros for VMS debug format. 32133 32134 -- Macro: VMS_DEBUGGING_INFO 32135 Define this macro if GCC should produce debugging output for VMS 32136 in response to the `-g' option. The default behavior for VMS is 32137 to generate minimal debug info for a traceback in the absence of 32138 `-g' unless explicitly overridden with `-g0'. This behavior is 32139 controlled by `OPTIMIZATION_OPTIONS' and `OVERRIDE_OPTIONS'. 32140 32141 32142 File: gccint.info, Node: Floating Point, Next: Mode Switching, Prev: Debugging Info, Up: Target Macros 32143 32144 17.23 Cross Compilation and Floating Point 32145 ========================================== 32146 32147 While all modern machines use twos-complement representation for 32148 integers, there are a variety of representations for floating point 32149 numbers. This means that in a cross-compiler the representation of 32150 floating point numbers in the compiled program may be different from 32151 that used in the machine doing the compilation. 32152 32153 Because different representation systems may offer different amounts of 32154 range and precision, all floating point constants must be represented in 32155 the target machine's format. Therefore, the cross compiler cannot 32156 safely use the host machine's floating point arithmetic; it must emulate 32157 the target's arithmetic. To ensure consistency, GCC always uses 32158 emulation to work with floating point values, even when the host and 32159 target floating point formats are identical. 32160 32161 The following macros are provided by `real.h' for the compiler to use. 32162 All parts of the compiler which generate or optimize floating-point 32163 calculations must use these macros. They may evaluate their operands 32164 more than once, so operands must not have side effects. 32165 32166 -- Macro: REAL_VALUE_TYPE 32167 The C data type to be used to hold a floating point value in the 32168 target machine's format. Typically this is a `struct' containing 32169 an array of `HOST_WIDE_INT', but all code should treat it as an 32170 opaque quantity. 32171 32172 -- Macro: int REAL_VALUES_EQUAL (REAL_VALUE_TYPE X, REAL_VALUE_TYPE Y) 32173 Compares for equality the two values, X and Y. If the target 32174 floating point format supports negative zeroes and/or NaNs, 32175 `REAL_VALUES_EQUAL (-0.0, 0.0)' is true, and `REAL_VALUES_EQUAL 32176 (NaN, NaN)' is false. 32177 32178 -- Macro: int REAL_VALUES_LESS (REAL_VALUE_TYPE X, REAL_VALUE_TYPE Y) 32179 Tests whether X is less than Y. 32180 32181 -- Macro: HOST_WIDE_INT REAL_VALUE_FIX (REAL_VALUE_TYPE X) 32182 Truncates X to a signed integer, rounding toward zero. 32183 32184 -- Macro: unsigned HOST_WIDE_INT REAL_VALUE_UNSIGNED_FIX 32185 (REAL_VALUE_TYPE X) 32186 Truncates X to an unsigned integer, rounding toward zero. If X is 32187 negative, returns zero. 32188 32189 -- Macro: REAL_VALUE_TYPE REAL_VALUE_ATOF (const char *STRING, enum 32190 machine_mode MODE) 32191 Converts STRING into a floating point number in the target 32192 machine's representation for mode MODE. This routine can handle 32193 both decimal and hexadecimal floating point constants, using the 32194 syntax defined by the C language for both. 32195 32196 -- Macro: int REAL_VALUE_NEGATIVE (REAL_VALUE_TYPE X) 32197 Returns 1 if X is negative (including negative zero), 0 otherwise. 32198 32199 -- Macro: int REAL_VALUE_ISINF (REAL_VALUE_TYPE X) 32200 Determines whether X represents infinity (positive or negative). 32201 32202 -- Macro: int REAL_VALUE_ISNAN (REAL_VALUE_TYPE X) 32203 Determines whether X represents a "NaN" (not-a-number). 32204 32205 -- Macro: void REAL_ARITHMETIC (REAL_VALUE_TYPE OUTPUT, enum tree_code 32206 CODE, REAL_VALUE_TYPE X, REAL_VALUE_TYPE Y) 32207 Calculates an arithmetic operation on the two floating point values 32208 X and Y, storing the result in OUTPUT (which must be a variable). 32209 32210 The operation to be performed is specified by CODE. Only the 32211 following codes are supported: `PLUS_EXPR', `MINUS_EXPR', 32212 `MULT_EXPR', `RDIV_EXPR', `MAX_EXPR', `MIN_EXPR'. 32213 32214 If `REAL_ARITHMETIC' is asked to evaluate division by zero and the 32215 target's floating point format cannot represent infinity, it will 32216 call `abort'. Callers should check for this situation first, using 32217 `MODE_HAS_INFINITIES'. *Note Storage Layout::. 32218 32219 -- Macro: REAL_VALUE_TYPE REAL_VALUE_NEGATE (REAL_VALUE_TYPE X) 32220 Returns the negative of the floating point value X. 32221 32222 -- Macro: REAL_VALUE_TYPE REAL_VALUE_ABS (REAL_VALUE_TYPE X) 32223 Returns the absolute value of X. 32224 32225 -- Macro: REAL_VALUE_TYPE REAL_VALUE_TRUNCATE (REAL_VALUE_TYPE MODE, 32226 enum machine_mode X) 32227 Truncates the floating point value X to fit in MODE. The return 32228 value is still a full-size `REAL_VALUE_TYPE', but it has an 32229 appropriate bit pattern to be output as a floating constant whose 32230 precision accords with mode MODE. 32231 32232 -- Macro: void REAL_VALUE_TO_INT (HOST_WIDE_INT LOW, HOST_WIDE_INT 32233 HIGH, REAL_VALUE_TYPE X) 32234 Converts a floating point value X into a double-precision integer 32235 which is then stored into LOW and HIGH. If the value is not 32236 integral, it is truncated. 32237 32238 -- Macro: void REAL_VALUE_FROM_INT (REAL_VALUE_TYPE X, HOST_WIDE_INT 32239 LOW, HOST_WIDE_INT HIGH, enum machine_mode MODE) 32240 Converts a double-precision integer found in LOW and HIGH, into a 32241 floating point value which is then stored into X. The value is 32242 truncated to fit in mode MODE. 32243 32244 32245 File: gccint.info, Node: Mode Switching, Next: Target Attributes, Prev: Floating Point, Up: Target Macros 32246 32247 17.24 Mode Switching Instructions 32248 ================================= 32249 32250 The following macros control mode switching optimizations: 32251 32252 -- Macro: OPTIMIZE_MODE_SWITCHING (ENTITY) 32253 Define this macro if the port needs extra instructions inserted 32254 for mode switching in an optimizing compilation. 32255 32256 For an example, the SH4 can perform both single and double 32257 precision floating point operations, but to perform a single 32258 precision operation, the FPSCR PR bit has to be cleared, while for 32259 a double precision operation, this bit has to be set. Changing 32260 the PR bit requires a general purpose register as a scratch 32261 register, hence these FPSCR sets have to be inserted before 32262 reload, i.e. you can't put this into instruction emitting or 32263 `TARGET_MACHINE_DEPENDENT_REORG'. 32264 32265 You can have multiple entities that are mode-switched, and select 32266 at run time which entities actually need it. 32267 `OPTIMIZE_MODE_SWITCHING' should return nonzero for any ENTITY 32268 that needs mode-switching. If you define this macro, you also 32269 have to define `NUM_MODES_FOR_MODE_SWITCHING', `MODE_NEEDED', 32270 `MODE_PRIORITY_TO_MODE' and `EMIT_MODE_SET'. `MODE_AFTER', 32271 `MODE_ENTRY', and `MODE_EXIT' are optional. 32272 32273 -- Macro: NUM_MODES_FOR_MODE_SWITCHING 32274 If you define `OPTIMIZE_MODE_SWITCHING', you have to define this as 32275 initializer for an array of integers. Each initializer element N 32276 refers to an entity that needs mode switching, and specifies the 32277 number of different modes that might need to be set for this 32278 entity. The position of the initializer in the 32279 initializer--starting counting at zero--determines the integer 32280 that is used to refer to the mode-switched entity in question. In 32281 macros that take mode arguments / yield a mode result, modes are 32282 represented as numbers 0 ... N - 1. N is used to specify that no 32283 mode switch is needed / supplied. 32284 32285 -- Macro: MODE_NEEDED (ENTITY, INSN) 32286 ENTITY is an integer specifying a mode-switched entity. If 32287 `OPTIMIZE_MODE_SWITCHING' is defined, you must define this macro to 32288 return an integer value not larger than the corresponding element 32289 in `NUM_MODES_FOR_MODE_SWITCHING', to denote the mode that ENTITY 32290 must be switched into prior to the execution of INSN. 32291 32292 -- Macro: MODE_AFTER (MODE, INSN) 32293 If this macro is defined, it is evaluated for every INSN during 32294 mode switching. It determines the mode that an insn results in (if 32295 different from the incoming mode). 32296 32297 -- Macro: MODE_ENTRY (ENTITY) 32298 If this macro is defined, it is evaluated for every ENTITY that 32299 needs mode switching. It should evaluate to an integer, which is 32300 a mode that ENTITY is assumed to be switched to at function entry. 32301 If `MODE_ENTRY' is defined then `MODE_EXIT' must be defined. 32302 32303 -- Macro: MODE_EXIT (ENTITY) 32304 If this macro is defined, it is evaluated for every ENTITY that 32305 needs mode switching. It should evaluate to an integer, which is 32306 a mode that ENTITY is assumed to be switched to at function exit. 32307 If `MODE_EXIT' is defined then `MODE_ENTRY' must be defined. 32308 32309 -- Macro: MODE_PRIORITY_TO_MODE (ENTITY, N) 32310 This macro specifies the order in which modes for ENTITY are 32311 processed. 0 is the highest priority, 32312 `NUM_MODES_FOR_MODE_SWITCHING[ENTITY] - 1' the lowest. The value 32313 of the macro should be an integer designating a mode for ENTITY. 32314 For any fixed ENTITY, `mode_priority_to_mode' (ENTITY, N) shall be 32315 a bijection in 0 ... `num_modes_for_mode_switching[ENTITY] - 1'. 32316 32317 -- Macro: EMIT_MODE_SET (ENTITY, MODE, HARD_REGS_LIVE) 32318 Generate one or more insns to set ENTITY to MODE. HARD_REG_LIVE 32319 is the set of hard registers live at the point where the insn(s) 32320 are to be inserted. 32321 32322 32323 File: gccint.info, Node: Target Attributes, Next: Emulated TLS, Prev: Mode Switching, Up: Target Macros 32324 32325 17.25 Defining target-specific uses of `__attribute__' 32326 ====================================================== 32327 32328 Target-specific attributes may be defined for functions, data and types. 32329 These are described using the following target hooks; they also need to 32330 be documented in `extend.texi'. 32331 32332 -- Target Hook: const struct attribute_spec * TARGET_ATTRIBUTE_TABLE 32333 If defined, this target hook points to an array of `struct 32334 attribute_spec' (defined in `tree.h') specifying the machine 32335 specific attributes for this target and some of the restrictions 32336 on the entities to which these attributes are applied and the 32337 arguments they take. 32338 32339 -- Target Hook: int TARGET_COMP_TYPE_ATTRIBUTES (tree TYPE1, tree 32340 TYPE2) 32341 If defined, this target hook is a function which returns zero if 32342 the attributes on TYPE1 and TYPE2 are incompatible, one if they 32343 are compatible, and two if they are nearly compatible (which 32344 causes a warning to be generated). If this is not defined, 32345 machine-specific attributes are supposed always to be compatible. 32346 32347 -- Target Hook: void TARGET_SET_DEFAULT_TYPE_ATTRIBUTES (tree TYPE) 32348 If defined, this target hook is a function which assigns default 32349 attributes to newly defined TYPE. 32350 32351 -- Target Hook: tree TARGET_MERGE_TYPE_ATTRIBUTES (tree TYPE1, tree 32352 TYPE2) 32353 Define this target hook if the merging of type attributes needs 32354 special handling. If defined, the result is a list of the combined 32355 `TYPE_ATTRIBUTES' of TYPE1 and TYPE2. It is assumed that 32356 `comptypes' has already been called and returned 1. This function 32357 may call `merge_attributes' to handle machine-independent merging. 32358 32359 -- Target Hook: tree TARGET_MERGE_DECL_ATTRIBUTES (tree OLDDECL, tree 32360 NEWDECL) 32361 Define this target hook if the merging of decl attributes needs 32362 special handling. If defined, the result is a list of the combined 32363 `DECL_ATTRIBUTES' of OLDDECL and NEWDECL. NEWDECL is a duplicate 32364 declaration of OLDDECL. Examples of when this is needed are when 32365 one attribute overrides another, or when an attribute is nullified 32366 by a subsequent definition. This function may call 32367 `merge_attributes' to handle machine-independent merging. 32368 32369 If the only target-specific handling you require is `dllimport' 32370 for Microsoft Windows targets, you should define the macro 32371 `TARGET_DLLIMPORT_DECL_ATTRIBUTES' to `1'. The compiler will then 32372 define a function called `merge_dllimport_decl_attributes' which 32373 can then be defined as the expansion of 32374 `TARGET_MERGE_DECL_ATTRIBUTES'. You can also add 32375 `handle_dll_attribute' in the attribute table for your port to 32376 perform initial processing of the `dllimport' and `dllexport' 32377 attributes. This is done in `i386/cygwin.h' and `i386/i386.c', 32378 for example. 32379 32380 -- Target Hook: bool TARGET_VALID_DLLIMPORT_ATTRIBUTE_P (tree DECL) 32381 DECL is a variable or function with `__attribute__((dllimport))' 32382 specified. Use this hook if the target needs to add extra 32383 validation checks to `handle_dll_attribute'. 32384 32385 -- Macro: TARGET_DECLSPEC 32386 Define this macro to a nonzero value if you want to treat 32387 `__declspec(X)' as equivalent to `__attribute((X))'. By default, 32388 this behavior is enabled only for targets that define 32389 `TARGET_DLLIMPORT_DECL_ATTRIBUTES'. The current implementation of 32390 `__declspec' is via a built-in macro, but you should not rely on 32391 this implementation detail. 32392 32393 -- Target Hook: void TARGET_INSERT_ATTRIBUTES (tree NODE, tree 32394 *ATTR_PTR) 32395 Define this target hook if you want to be able to add attributes 32396 to a decl when it is being created. This is normally useful for 32397 back ends which wish to implement a pragma by using the attributes 32398 which correspond to the pragma's effect. The NODE argument is the 32399 decl which is being created. The ATTR_PTR argument is a pointer 32400 to the attribute list for this decl. The list itself should not 32401 be modified, since it may be shared with other decls, but 32402 attributes may be chained on the head of the list and `*ATTR_PTR' 32403 modified to point to the new attributes, or a copy of the list may 32404 be made if further changes are needed. 32405 32406 -- Target Hook: bool TARGET_FUNCTION_ATTRIBUTE_INLINABLE_P (tree 32407 FNDECL) 32408 This target hook returns `true' if it is ok to inline FNDECL into 32409 the current function, despite its having target-specific 32410 attributes, `false' otherwise. By default, if a function has a 32411 target specific attribute attached to it, it will not be inlined. 32412 32413 -- Target Hook: bool TARGET_VALID_OPTION_ATTRIBUTE_P (tree FNDECL, 32414 tree NAME, tree ARGS, int FLAGS) 32415 This hook is called to parse the `attribute(option("..."))', and 32416 it allows the function to set different target machine compile time 32417 options for the current function that might be different than the 32418 options specified on the command line. The hook should return 32419 `true' if the options are valid. 32420 32421 The hook should set the DECL_FUNCTION_SPECIFIC_TARGET field in the 32422 function declaration to hold a pointer to a target specific STRUCT 32423 CL_TARGET_OPTION structure. 32424 32425 -- Target Hook: void TARGET_OPTION_SAVE (struct cl_target_option *PTR) 32426 This hook is called to save any additional target specific 32427 information in the STRUCT CL_TARGET_OPTION structure for function 32428 specific options. *Note Option file format::. 32429 32430 -- Target Hook: void TARGET_OPTION_RESTORE (struct cl_target_option 32431 *PTR) 32432 This hook is called to restore any additional target specific 32433 information in the STRUCT CL_TARGET_OPTION structure for function 32434 specific options. 32435 32436 -- Target Hook: void TARGET_OPTION_PRINT (struct cl_target_option *PTR) 32437 This hook is called to print any additional target specific 32438 information in the STRUCT CL_TARGET_OPTION structure for function 32439 specific options. 32440 32441 -- Target Hook: bool TARGET_OPTION_PRAGMA_PARSE (target ARGS) 32442 This target hook parses the options for `#pragma GCC option' to 32443 set the machine specific options for functions that occur later in 32444 the input stream. The options should be the same as handled by the 32445 `TARGET_VALID_OPTION_ATTRIBUTE_P' hook. 32446 32447 -- Target Hook: bool TARGET_CAN_INLINE_P (tree CALLER, tree CALLEE) 32448 This target hook returns `false' if the CALLER function cannot 32449 inline CALLEE, based on target specific information. By default, 32450 inlining is not allowed if the callee function has function 32451 specific target options and the caller does not use the same 32452 options. 32453 32454 32455 File: gccint.info, Node: Emulated TLS, Next: MIPS Coprocessors, Prev: Target Attributes, Up: Target Macros 32456 32457 17.26 Emulating TLS 32458 =================== 32459 32460 For targets whose psABI does not provide Thread Local Storage via 32461 specific relocations and instruction sequences, an emulation layer is 32462 used. A set of target hooks allows this emulation layer to be 32463 configured for the requirements of a particular target. For instance 32464 the psABI may in fact specify TLS support in terms of an emulation 32465 layer. 32466 32467 The emulation layer works by creating a control object for every TLS 32468 object. To access the TLS object, a lookup function is provided which, 32469 when given the address of the control object, will return the address 32470 of the current thread's instance of the TLS object. 32471 32472 -- Target Hook: const char * TARGET_EMUTLS_GET_ADDRESS 32473 Contains the name of the helper function that uses a TLS control 32474 object to locate a TLS instance. The default causes libgcc's 32475 emulated TLS helper function to be used. 32476 32477 -- Target Hook: const char * TARGET_EMUTLS_REGISTER_COMMON 32478 Contains the name of the helper function that should be used at 32479 program startup to register TLS objects that are implicitly 32480 initialized to zero. If this is `NULL', all TLS objects will have 32481 explicit initializers. The default causes libgcc's emulated TLS 32482 registration function to be used. 32483 32484 -- Target Hook: const char * TARGET_EMUTLS_VAR_SECTION 32485 Contains the name of the section in which TLS control variables 32486 should be placed. The default of `NULL' allows these to be placed 32487 in any section. 32488 32489 -- Target Hook: const char * TARGET_EMUTLS_TMPL_SECTION 32490 Contains the name of the section in which TLS initializers should 32491 be placed. The default of `NULL' allows these to be placed in any 32492 section. 32493 32494 -- Target Hook: const char * TARGET_EMUTLS_VAR_PREFIX 32495 Contains the prefix to be prepended to TLS control variable names. 32496 The default of `NULL' uses a target-specific prefix. 32497 32498 -- Target Hook: const char * TARGET_EMUTLS_TMPL_PREFIX 32499 Contains the prefix to be prepended to TLS initializer objects. 32500 The default of `NULL' uses a target-specific prefix. 32501 32502 -- Target Hook: tree TARGET_EMUTLS_VAR_FIELDS (tree TYPE, tree *NAME) 32503 Specifies a function that generates the FIELD_DECLs for a TLS 32504 control object type. TYPE is the RECORD_TYPE the fields are for 32505 and NAME should be filled with the structure tag, if the default of 32506 `__emutls_object' is unsuitable. The default creates a type 32507 suitable for libgcc's emulated TLS function. 32508 32509 -- Target Hook: tree TARGET_EMUTLS_VAR_INIT (tree VAR, tree DECL, tree 32510 TMPL_ADDR) 32511 Specifies a function that generates the CONSTRUCTOR to initialize a 32512 TLS control object. VAR is the TLS control object, DECL is the 32513 TLS object and TMPL_ADDR is the address of the initializer. The 32514 default initializes libgcc's emulated TLS control object. 32515 32516 -- Target Hook: bool TARGET_EMUTLS_VAR_ALIGN_FIXED 32517 Specifies whether the alignment of TLS control variable objects is 32518 fixed and should not be increased as some backends may do to 32519 optimize single objects. The default is false. 32520 32521 -- Target Hook: bool TARGET_EMUTLS_DEBUG_FORM_TLS_ADDRESS 32522 Specifies whether a DWARF `DW_OP_form_tls_address' location 32523 descriptor may be used to describe emulated TLS control objects. 32524 32525 32526 File: gccint.info, Node: MIPS Coprocessors, Next: PCH Target, Prev: Emulated TLS, Up: Target Macros 32527 32528 17.27 Defining coprocessor specifics for MIPS targets. 32529 ====================================================== 32530 32531 The MIPS specification allows MIPS implementations to have as many as 4 32532 coprocessors, each with as many as 32 private registers. GCC supports 32533 accessing these registers and transferring values between the registers 32534 and memory using asm-ized variables. For example: 32535 32536 register unsigned int cp0count asm ("c0r1"); 32537 unsigned int d; 32538 32539 d = cp0count + 3; 32540 32541 ("c0r1" is the default name of register 1 in coprocessor 0; alternate 32542 names may be added as described below, or the default names may be 32543 overridden entirely in `SUBTARGET_CONDITIONAL_REGISTER_USAGE'.) 32544 32545 Coprocessor registers are assumed to be epilogue-used; sets to them 32546 will be preserved even if it does not appear that the register is used 32547 again later in the function. 32548 32549 Another note: according to the MIPS spec, coprocessor 1 (if present) is 32550 the FPU. One accesses COP1 registers through standard mips 32551 floating-point support; they are not included in this mechanism. 32552 32553 There is one macro used in defining the MIPS coprocessor interface 32554 which you may want to override in subtargets; it is described below. 32555 32556 -- Macro: ALL_COP_ADDITIONAL_REGISTER_NAMES 32557 A comma-separated list (with leading comma) of pairs describing the 32558 alternate names of coprocessor registers. The format of each 32559 entry should be 32560 { ALTERNATENAME, REGISTER_NUMBER} 32561 Default: empty. 32562 32563 32564 File: gccint.info, Node: PCH Target, Next: C++ ABI, Prev: MIPS Coprocessors, Up: Target Macros 32565 32566 17.28 Parameters for Precompiled Header Validity Checking 32567 ========================================================= 32568 32569 -- Target Hook: void *TARGET_GET_PCH_VALIDITY (size_t *SZ) 32570 This hook returns the data needed by `TARGET_PCH_VALID_P' and sets 32571 `*SZ' to the size of the data in bytes. 32572 32573 -- Target Hook: const char *TARGET_PCH_VALID_P (const void *DATA, 32574 size_t SZ) 32575 This hook checks whether the options used to create a PCH file are 32576 compatible with the current settings. It returns `NULL' if so and 32577 a suitable error message if not. Error messages will be presented 32578 to the user and must be localized using `_(MSG)'. 32579 32580 DATA is the data that was returned by `TARGET_GET_PCH_VALIDITY' 32581 when the PCH file was created and SZ is the size of that data in 32582 bytes. It's safe to assume that the data was created by the same 32583 version of the compiler, so no format checking is needed. 32584 32585 The default definition of `default_pch_valid_p' should be suitable 32586 for most targets. 32587 32588 -- Target Hook: const char *TARGET_CHECK_PCH_TARGET_FLAGS (int 32589 PCH_FLAGS) 32590 If this hook is nonnull, the default implementation of 32591 `TARGET_PCH_VALID_P' will use it to check for compatible values of 32592 `target_flags'. PCH_FLAGS specifies the value that `target_flags' 32593 had when the PCH file was created. The return value is the same 32594 as for `TARGET_PCH_VALID_P'. 32595 32596 32597 File: gccint.info, Node: C++ ABI, Next: Misc, Prev: PCH Target, Up: Target Macros 32598 32599 17.29 C++ ABI parameters 32600 ======================== 32601 32602 -- Target Hook: tree TARGET_CXX_GUARD_TYPE (void) 32603 Define this hook to override the integer type used for guard 32604 variables. These are used to implement one-time construction of 32605 static objects. The default is long_long_integer_type_node. 32606 32607 -- Target Hook: bool TARGET_CXX_GUARD_MASK_BIT (void) 32608 This hook determines how guard variables are used. It should 32609 return `false' (the default) if first byte should be used. A 32610 return value of `true' indicates the least significant bit should 32611 be used. 32612 32613 -- Target Hook: tree TARGET_CXX_GET_COOKIE_SIZE (tree TYPE) 32614 This hook returns the size of the cookie to use when allocating an 32615 array whose elements have the indicated TYPE. Assumes that it is 32616 already known that a cookie is needed. The default is `max(sizeof 32617 (size_t), alignof(type))', as defined in section 2.7 of the 32618 IA64/Generic C++ ABI. 32619 32620 -- Target Hook: bool TARGET_CXX_COOKIE_HAS_SIZE (void) 32621 This hook should return `true' if the element size should be 32622 stored in array cookies. The default is to return `false'. 32623 32624 -- Target Hook: int TARGET_CXX_IMPORT_EXPORT_CLASS (tree TYPE, int 32625 IMPORT_EXPORT) 32626 If defined by a backend this hook allows the decision made to 32627 export class TYPE to be overruled. Upon entry IMPORT_EXPORT will 32628 contain 1 if the class is going to be exported, -1 if it is going 32629 to be imported and 0 otherwise. This function should return the 32630 modified value and perform any other actions necessary to support 32631 the backend's targeted operating system. 32632 32633 -- Target Hook: bool TARGET_CXX_CDTOR_RETURNS_THIS (void) 32634 This hook should return `true' if constructors and destructors 32635 return the address of the object created/destroyed. The default 32636 is to return `false'. 32637 32638 -- Target Hook: bool TARGET_CXX_KEY_METHOD_MAY_BE_INLINE (void) 32639 This hook returns true if the key method for a class (i.e., the 32640 method which, if defined in the current translation unit, causes 32641 the virtual table to be emitted) may be an inline function. Under 32642 the standard Itanium C++ ABI the key method may be an inline 32643 function so long as the function is not declared inline in the 32644 class definition. Under some variants of the ABI, an inline 32645 function can never be the key method. The default is to return 32646 `true'. 32647 32648 -- Target Hook: void TARGET_CXX_DETERMINE_CLASS_DATA_VISIBILITY (tree 32649 DECL) 32650 DECL is a virtual table, virtual table table, typeinfo object, or 32651 other similar implicit class data object that will be emitted with 32652 external linkage in this translation unit. No ELF visibility has 32653 been explicitly specified. If the target needs to specify a 32654 visibility other than that of the containing class, use this hook 32655 to set `DECL_VISIBILITY' and `DECL_VISIBILITY_SPECIFIED'. 32656 32657 -- Target Hook: bool TARGET_CXX_CLASS_DATA_ALWAYS_COMDAT (void) 32658 This hook returns true (the default) if virtual tables and other 32659 similar implicit class data objects are always COMDAT if they have 32660 external linkage. If this hook returns false, then class data for 32661 classes whose virtual table will be emitted in only one translation 32662 unit will not be COMDAT. 32663 32664 -- Target Hook: bool TARGET_CXX_LIBRARY_RTTI_COMDAT (void) 32665 This hook returns true (the default) if the RTTI information for 32666 the basic types which is defined in the C++ runtime should always 32667 be COMDAT, false if it should not be COMDAT. 32668 32669 -- Target Hook: bool TARGET_CXX_USE_AEABI_ATEXIT (void) 32670 This hook returns true if `__aeabi_atexit' (as defined by the ARM 32671 EABI) should be used to register static destructors when 32672 `-fuse-cxa-atexit' is in effect. The default is to return false 32673 to use `__cxa_atexit'. 32674 32675 -- Target Hook: bool TARGET_CXX_USE_ATEXIT_FOR_CXA_ATEXIT (void) 32676 This hook returns true if the target `atexit' function can be used 32677 in the same manner as `__cxa_atexit' to register C++ static 32678 destructors. This requires that `atexit'-registered functions in 32679 shared libraries are run in the correct order when the libraries 32680 are unloaded. The default is to return false. 32681 32682 -- Target Hook: void TARGET_CXX_ADJUST_CLASS_AT_DEFINITION (tree TYPE) 32683 TYPE is a C++ class (i.e., RECORD_TYPE or UNION_TYPE) that has 32684 just been defined. Use this hook to make adjustments to the class 32685 (eg, tweak visibility or perform any other required target 32686 modifications). 32687 32688 32689 File: gccint.info, Node: Misc, Prev: C++ ABI, Up: Target Macros 32690 32691 17.30 Miscellaneous Parameters 32692 ============================== 32693 32694 Here are several miscellaneous parameters. 32695 32696 -- Macro: HAS_LONG_COND_BRANCH 32697 Define this boolean macro to indicate whether or not your 32698 architecture has conditional branches that can span all of memory. 32699 It is used in conjunction with an optimization that partitions 32700 hot and cold basic blocks into separate sections of the 32701 executable. If this macro is set to false, gcc will convert any 32702 conditional branches that attempt to cross between sections into 32703 unconditional branches or indirect jumps. 32704 32705 -- Macro: HAS_LONG_UNCOND_BRANCH 32706 Define this boolean macro to indicate whether or not your 32707 architecture has unconditional branches that can span all of 32708 memory. It is used in conjunction with an optimization that 32709 partitions hot and cold basic blocks into separate sections of the 32710 executable. If this macro is set to false, gcc will convert any 32711 unconditional branches that attempt to cross between sections into 32712 indirect jumps. 32713 32714 -- Macro: CASE_VECTOR_MODE 32715 An alias for a machine mode name. This is the machine mode that 32716 elements of a jump-table should have. 32717 32718 -- Macro: CASE_VECTOR_SHORTEN_MODE (MIN_OFFSET, MAX_OFFSET, BODY) 32719 Optional: return the preferred mode for an `addr_diff_vec' when 32720 the minimum and maximum offset are known. If you define this, it 32721 enables extra code in branch shortening to deal with 32722 `addr_diff_vec'. To make this work, you also have to define 32723 `INSN_ALIGN' and make the alignment for `addr_diff_vec' explicit. 32724 The BODY argument is provided so that the offset_unsigned and scale 32725 flags can be updated. 32726 32727 -- Macro: CASE_VECTOR_PC_RELATIVE 32728 Define this macro to be a C expression to indicate when jump-tables 32729 should contain relative addresses. You need not define this macro 32730 if jump-tables never contain relative addresses, or jump-tables 32731 should contain relative addresses only when `-fPIC' or `-fPIC' is 32732 in effect. 32733 32734 -- Macro: CASE_VALUES_THRESHOLD 32735 Define this to be the smallest number of different values for 32736 which it is best to use a jump-table instead of a tree of 32737 conditional branches. The default is four for machines with a 32738 `casesi' instruction and five otherwise. This is best for most 32739 machines. 32740 32741 -- Macro: CASE_USE_BIT_TESTS 32742 Define this macro to be a C expression to indicate whether C switch 32743 statements may be implemented by a sequence of bit tests. This is 32744 advantageous on processors that can efficiently implement left 32745 shift of 1 by the number of bits held in a register, but 32746 inappropriate on targets that would require a loop. By default, 32747 this macro returns `true' if the target defines an `ashlsi3' 32748 pattern, and `false' otherwise. 32749 32750 -- Macro: WORD_REGISTER_OPERATIONS 32751 Define this macro if operations between registers with integral 32752 mode smaller than a word are always performed on the entire 32753 register. Most RISC machines have this property and most CISC 32754 machines do not. 32755 32756 -- Macro: LOAD_EXTEND_OP (MEM_MODE) 32757 Define this macro to be a C expression indicating when insns that 32758 read memory in MEM_MODE, an integral mode narrower than a word, 32759 set the bits outside of MEM_MODE to be either the sign-extension 32760 or the zero-extension of the data read. Return `SIGN_EXTEND' for 32761 values of MEM_MODE for which the insn sign-extends, `ZERO_EXTEND' 32762 for which it zero-extends, and `UNKNOWN' for other modes. 32763 32764 This macro is not called with MEM_MODE non-integral or with a width 32765 greater than or equal to `BITS_PER_WORD', so you may return any 32766 value in this case. Do not define this macro if it would always 32767 return `UNKNOWN'. On machines where this macro is defined, you 32768 will normally define it as the constant `SIGN_EXTEND' or 32769 `ZERO_EXTEND'. 32770 32771 You may return a non-`UNKNOWN' value even if for some hard 32772 registers the sign extension is not performed, if for the 32773 `REGNO_REG_CLASS' of these hard registers 32774 `CANNOT_CHANGE_MODE_CLASS' returns nonzero when the FROM mode is 32775 MEM_MODE and the TO mode is any integral mode larger than this but 32776 not larger than `word_mode'. 32777 32778 You must return `UNKNOWN' if for some hard registers that allow 32779 this mode, `CANNOT_CHANGE_MODE_CLASS' says that they cannot change 32780 to `word_mode', but that they can change to another integral mode 32781 that is larger then MEM_MODE but still smaller than `word_mode'. 32782 32783 -- Macro: SHORT_IMMEDIATES_SIGN_EXTEND 32784 Define this macro if loading short immediate values into registers 32785 sign extends. 32786 32787 -- Macro: FIXUNS_TRUNC_LIKE_FIX_TRUNC 32788 Define this macro if the same instructions that convert a floating 32789 point number to a signed fixed point number also convert validly 32790 to an unsigned one. 32791 32792 -- Target Hook: int TARGET_MIN_DIVISIONS_FOR_RECIP_MUL (enum 32793 machine_mode MODE) 32794 When `-ffast-math' is in effect, GCC tries to optimize divisions 32795 by the same divisor, by turning them into multiplications by the 32796 reciprocal. This target hook specifies the minimum number of 32797 divisions that should be there for GCC to perform the optimization 32798 for a variable of mode MODE. The default implementation returns 3 32799 if the machine has an instruction for the division, and 2 if it 32800 does not. 32801 32802 -- Macro: MOVE_MAX 32803 The maximum number of bytes that a single instruction can move 32804 quickly between memory and registers or between two memory 32805 locations. 32806 32807 -- Macro: MAX_MOVE_MAX 32808 The maximum number of bytes that a single instruction can move 32809 quickly between memory and registers or between two memory 32810 locations. If this is undefined, the default is `MOVE_MAX'. 32811 Otherwise, it is the constant value that is the largest value that 32812 `MOVE_MAX' can have at run-time. 32813 32814 -- Macro: SHIFT_COUNT_TRUNCATED 32815 A C expression that is nonzero if on this machine the number of 32816 bits actually used for the count of a shift operation is equal to 32817 the number of bits needed to represent the size of the object 32818 being shifted. When this macro is nonzero, the compiler will 32819 assume that it is safe to omit a sign-extend, zero-extend, and 32820 certain bitwise `and' instructions that truncates the count of a 32821 shift operation. On machines that have instructions that act on 32822 bit-fields at variable positions, which may include `bit test' 32823 instructions, a nonzero `SHIFT_COUNT_TRUNCATED' also enables 32824 deletion of truncations of the values that serve as arguments to 32825 bit-field instructions. 32826 32827 If both types of instructions truncate the count (for shifts) and 32828 position (for bit-field operations), or if no variable-position 32829 bit-field instructions exist, you should define this macro. 32830 32831 However, on some machines, such as the 80386 and the 680x0, 32832 truncation only applies to shift operations and not the (real or 32833 pretended) bit-field operations. Define `SHIFT_COUNT_TRUNCATED' 32834 to be zero on such machines. Instead, add patterns to the `md' 32835 file that include the implied truncation of the shift instructions. 32836 32837 You need not define this macro if it would always have the value 32838 of zero. 32839 32840 -- Target Hook: int TARGET_SHIFT_TRUNCATION_MASK (enum machine_mode 32841 MODE) 32842 This function describes how the standard shift patterns for MODE 32843 deal with shifts by negative amounts or by more than the width of 32844 the mode. *Note shift patterns::. 32845 32846 On many machines, the shift patterns will apply a mask M to the 32847 shift count, meaning that a fixed-width shift of X by Y is 32848 equivalent to an arbitrary-width shift of X by Y & M. If this is 32849 true for mode MODE, the function should return M, otherwise it 32850 should return 0. A return value of 0 indicates that no particular 32851 behavior is guaranteed. 32852 32853 Note that, unlike `SHIFT_COUNT_TRUNCATED', this function does 32854 _not_ apply to general shift rtxes; it applies only to instructions 32855 that are generated by the named shift patterns. 32856 32857 The default implementation of this function returns 32858 `GET_MODE_BITSIZE (MODE) - 1' if `SHIFT_COUNT_TRUNCATED' and 0 32859 otherwise. This definition is always safe, but if 32860 `SHIFT_COUNT_TRUNCATED' is false, and some shift patterns 32861 nevertheless truncate the shift count, you may get better code by 32862 overriding it. 32863 32864 -- Macro: TRULY_NOOP_TRUNCATION (OUTPREC, INPREC) 32865 A C expression which is nonzero if on this machine it is safe to 32866 "convert" an integer of INPREC bits to one of OUTPREC bits (where 32867 OUTPREC is smaller than INPREC) by merely operating on it as if it 32868 had only OUTPREC bits. 32869 32870 On many machines, this expression can be 1. 32871 32872 When `TRULY_NOOP_TRUNCATION' returns 1 for a pair of sizes for 32873 modes for which `MODES_TIEABLE_P' is 0, suboptimal code can result. 32874 If this is the case, making `TRULY_NOOP_TRUNCATION' return 0 in 32875 such cases may improve things. 32876 32877 -- Target Hook: int TARGET_MODE_REP_EXTENDED (enum machine_mode MODE, 32878 enum machine_mode REP_MODE) 32879 The representation of an integral mode can be such that the values 32880 are always extended to a wider integral mode. Return 32881 `SIGN_EXTEND' if values of MODE are represented in sign-extended 32882 form to REP_MODE. Return `UNKNOWN' otherwise. (Currently, none 32883 of the targets use zero-extended representation this way so unlike 32884 `LOAD_EXTEND_OP', `TARGET_MODE_REP_EXTENDED' is expected to return 32885 either `SIGN_EXTEND' or `UNKNOWN'. Also no target extends MODE to 32886 MODE_REP so that MODE_REP is not the next widest integral mode and 32887 currently we take advantage of this fact.) 32888 32889 Similarly to `LOAD_EXTEND_OP' you may return a non-`UNKNOWN' value 32890 even if the extension is not performed on certain hard registers 32891 as long as for the `REGNO_REG_CLASS' of these hard registers 32892 `CANNOT_CHANGE_MODE_CLASS' returns nonzero. 32893 32894 Note that `TARGET_MODE_REP_EXTENDED' and `LOAD_EXTEND_OP' describe 32895 two related properties. If you define `TARGET_MODE_REP_EXTENDED 32896 (mode, word_mode)' you probably also want to define 32897 `LOAD_EXTEND_OP (mode)' to return the same type of extension. 32898 32899 In order to enforce the representation of `mode', 32900 `TRULY_NOOP_TRUNCATION' should return false when truncating to 32901 `mode'. 32902 32903 -- Macro: STORE_FLAG_VALUE 32904 A C expression describing the value returned by a comparison 32905 operator with an integral mode and stored by a store-flag 32906 instruction (`sCOND') when the condition is true. This 32907 description must apply to _all_ the `sCOND' patterns and all the 32908 comparison operators whose results have a `MODE_INT' mode. 32909 32910 A value of 1 or -1 means that the instruction implementing the 32911 comparison operator returns exactly 1 or -1 when the comparison is 32912 true and 0 when the comparison is false. Otherwise, the value 32913 indicates which bits of the result are guaranteed to be 1 when the 32914 comparison is true. This value is interpreted in the mode of the 32915 comparison operation, which is given by the mode of the first 32916 operand in the `sCOND' pattern. Either the low bit or the sign 32917 bit of `STORE_FLAG_VALUE' be on. Presently, only those bits are 32918 used by the compiler. 32919 32920 If `STORE_FLAG_VALUE' is neither 1 or -1, the compiler will 32921 generate code that depends only on the specified bits. It can also 32922 replace comparison operators with equivalent operations if they 32923 cause the required bits to be set, even if the remaining bits are 32924 undefined. For example, on a machine whose comparison operators 32925 return an `SImode' value and where `STORE_FLAG_VALUE' is defined as 32926 `0x80000000', saying that just the sign bit is relevant, the 32927 expression 32928 32929 (ne:SI (and:SI X (const_int POWER-OF-2)) (const_int 0)) 32930 32931 can be converted to 32932 32933 (ashift:SI X (const_int N)) 32934 32935 where N is the appropriate shift count to move the bit being 32936 tested into the sign bit. 32937 32938 There is no way to describe a machine that always sets the 32939 low-order bit for a true value, but does not guarantee the value 32940 of any other bits, but we do not know of any machine that has such 32941 an instruction. If you are trying to port GCC to such a machine, 32942 include an instruction to perform a logical-and of the result with 32943 1 in the pattern for the comparison operators and let us know at 32944 <gcc (a] gcc.gnu.org>. 32945 32946 Often, a machine will have multiple instructions that obtain a 32947 value from a comparison (or the condition codes). Here are rules 32948 to guide the choice of value for `STORE_FLAG_VALUE', and hence the 32949 instructions to be used: 32950 32951 * Use the shortest sequence that yields a valid definition for 32952 `STORE_FLAG_VALUE'. It is more efficient for the compiler to 32953 "normalize" the value (convert it to, e.g., 1 or 0) than for 32954 the comparison operators to do so because there may be 32955 opportunities to combine the normalization with other 32956 operations. 32957 32958 * For equal-length sequences, use a value of 1 or -1, with -1 32959 being slightly preferred on machines with expensive jumps and 32960 1 preferred on other machines. 32961 32962 * As a second choice, choose a value of `0x80000001' if 32963 instructions exist that set both the sign and low-order bits 32964 but do not define the others. 32965 32966 * Otherwise, use a value of `0x80000000'. 32967 32968 Many machines can produce both the value chosen for 32969 `STORE_FLAG_VALUE' and its negation in the same number of 32970 instructions. On those machines, you should also define a pattern 32971 for those cases, e.g., one matching 32972 32973 (set A (neg:M (ne:M B C))) 32974 32975 Some machines can also perform `and' or `plus' operations on 32976 condition code values with less instructions than the corresponding 32977 `sCOND' insn followed by `and' or `plus'. On those machines, 32978 define the appropriate patterns. Use the names `incscc' and 32979 `decscc', respectively, for the patterns which perform `plus' or 32980 `minus' operations on condition code values. See `rs6000.md' for 32981 some examples. The GNU Superoptizer can be used to find such 32982 instruction sequences on other machines. 32983 32984 If this macro is not defined, the default value, 1, is used. You 32985 need not define `STORE_FLAG_VALUE' if the machine has no store-flag 32986 instructions, or if the value generated by these instructions is 1. 32987 32988 -- Macro: FLOAT_STORE_FLAG_VALUE (MODE) 32989 A C expression that gives a nonzero `REAL_VALUE_TYPE' value that is 32990 returned when comparison operators with floating-point results are 32991 true. Define this macro on machines that have comparison 32992 operations that return floating-point values. If there are no 32993 such operations, do not define this macro. 32994 32995 -- Macro: VECTOR_STORE_FLAG_VALUE (MODE) 32996 A C expression that gives a rtx representing the nonzero true 32997 element for vector comparisons. The returned rtx should be valid 32998 for the inner mode of MODE which is guaranteed to be a vector 32999 mode. Define this macro on machines that have vector comparison 33000 operations that return a vector result. If there are no such 33001 operations, do not define this macro. Typically, this macro is 33002 defined as `const1_rtx' or `constm1_rtx'. This macro may return 33003 `NULL_RTX' to prevent the compiler optimizing such vector 33004 comparison operations for the given mode. 33005 33006 -- Macro: CLZ_DEFINED_VALUE_AT_ZERO (MODE, VALUE) 33007 -- Macro: CTZ_DEFINED_VALUE_AT_ZERO (MODE, VALUE) 33008 A C expression that indicates whether the architecture defines a 33009 value for `clz' or `ctz' with a zero operand. A result of `0' 33010 indicates the value is undefined. If the value is defined for 33011 only the RTL expression, the macro should evaluate to `1'; if the 33012 value applies also to the corresponding optab entry (which is 33013 normally the case if it expands directly into the corresponding 33014 RTL), then the macro should evaluate to `2'. In the cases where 33015 the value is defined, VALUE should be set to this value. 33016 33017 If this macro is not defined, the value of `clz' or `ctz' at zero 33018 is assumed to be undefined. 33019 33020 This macro must be defined if the target's expansion for `ffs' 33021 relies on a particular value to get correct results. Otherwise it 33022 is not necessary, though it may be used to optimize some corner 33023 cases, and to provide a default expansion for the `ffs' optab. 33024 33025 Note that regardless of this macro the "definedness" of `clz' and 33026 `ctz' at zero do _not_ extend to the builtin functions visible to 33027 the user. Thus one may be free to adjust the value at will to 33028 match the target expansion of these operations without fear of 33029 breaking the API. 33030 33031 -- Macro: Pmode 33032 An alias for the machine mode for pointers. On most machines, 33033 define this to be the integer mode corresponding to the width of a 33034 hardware pointer; `SImode' on 32-bit machine or `DImode' on 64-bit 33035 machines. On some machines you must define this to be one of the 33036 partial integer modes, such as `PSImode'. 33037 33038 The width of `Pmode' must be at least as large as the value of 33039 `POINTER_SIZE'. If it is not equal, you must define the macro 33040 `POINTERS_EXTEND_UNSIGNED' to specify how pointers are extended to 33041 `Pmode'. 33042 33043 -- Macro: FUNCTION_MODE 33044 An alias for the machine mode used for memory references to 33045 functions being called, in `call' RTL expressions. On most CISC 33046 machines, where an instruction can begin at any byte address, this 33047 should be `QImode'. On most RISC machines, where all instructions 33048 have fixed size and alignment, this should be a mode with the same 33049 size and alignment as the machine instruction words - typically 33050 `SImode' or `HImode'. 33051 33052 -- Macro: STDC_0_IN_SYSTEM_HEADERS 33053 In normal operation, the preprocessor expands `__STDC__' to the 33054 constant 1, to signify that GCC conforms to ISO Standard C. On 33055 some hosts, like Solaris, the system compiler uses a different 33056 convention, where `__STDC__' is normally 0, but is 1 if the user 33057 specifies strict conformance to the C Standard. 33058 33059 Defining `STDC_0_IN_SYSTEM_HEADERS' makes GNU CPP follows the host 33060 convention when processing system header files, but when 33061 processing user files `__STDC__' will always expand to 1. 33062 33063 -- Macro: NO_IMPLICIT_EXTERN_C 33064 Define this macro if the system header files support C++ as well 33065 as C. This macro inhibits the usual method of using system header 33066 files in C++, which is to pretend that the file's contents are 33067 enclosed in `extern "C" {...}'. 33068 33069 -- Macro: REGISTER_TARGET_PRAGMAS () 33070 Define this macro if you want to implement any target-specific 33071 pragmas. If defined, it is a C expression which makes a series of 33072 calls to `c_register_pragma' or `c_register_pragma_with_expansion' 33073 for each pragma. The macro may also do any setup required for the 33074 pragmas. 33075 33076 The primary reason to define this macro is to provide 33077 compatibility with other compilers for the same target. In 33078 general, we discourage definition of target-specific pragmas for 33079 GCC. 33080 33081 If the pragma can be implemented by attributes then you should 33082 consider defining the target hook `TARGET_INSERT_ATTRIBUTES' as 33083 well. 33084 33085 Preprocessor macros that appear on pragma lines are not expanded. 33086 All `#pragma' directives that do not match any registered pragma 33087 are silently ignored, unless the user specifies 33088 `-Wunknown-pragmas'. 33089 33090 -- Function: void c_register_pragma (const char *SPACE, const char 33091 *NAME, void (*CALLBACK) (struct cpp_reader *)) 33092 -- Function: void c_register_pragma_with_expansion (const char *SPACE, 33093 const char *NAME, void (*CALLBACK) (struct cpp_reader *)) 33094 Each call to `c_register_pragma' or 33095 `c_register_pragma_with_expansion' establishes one pragma. The 33096 CALLBACK routine will be called when the preprocessor encounters a 33097 pragma of the form 33098 33099 #pragma [SPACE] NAME ... 33100 33101 SPACE is the case-sensitive namespace of the pragma, or `NULL' to 33102 put the pragma in the global namespace. The callback routine 33103 receives PFILE as its first argument, which can be passed on to 33104 cpplib's functions if necessary. You can lex tokens after the 33105 NAME by calling `pragma_lex'. Tokens that are not read by the 33106 callback will be silently ignored. The end of the line is 33107 indicated by a token of type `CPP_EOF'. Macro expansion occurs on 33108 the arguments of pragmas registered with 33109 `c_register_pragma_with_expansion' but not on the arguments of 33110 pragmas registered with `c_register_pragma'. 33111 33112 Note that the use of `pragma_lex' is specific to the C and C++ 33113 compilers. It will not work in the Java or Fortran compilers, or 33114 any other language compilers for that matter. Thus if 33115 `pragma_lex' is going to be called from target-specific code, it 33116 must only be done so when building the C and C++ compilers. This 33117 can be done by defining the variables `c_target_objs' and 33118 `cxx_target_objs' in the target entry in the `config.gcc' file. 33119 These variables should name the target-specific, language-specific 33120 object file which contains the code that uses `pragma_lex'. Note 33121 it will also be necessary to add a rule to the makefile fragment 33122 pointed to by `tmake_file' that shows how to build this object 33123 file. 33124 33125 -- Macro: HANDLE_SYSV_PRAGMA 33126 Define this macro (to a value of 1) if you want the System V style 33127 pragmas `#pragma pack(<n>)' and `#pragma weak <name> [=<value>]' 33128 to be supported by gcc. 33129 33130 The pack pragma specifies the maximum alignment (in bytes) of 33131 fields within a structure, in much the same way as the 33132 `__aligned__' and `__packed__' `__attribute__'s do. A pack value 33133 of zero resets the behavior to the default. 33134 33135 A subtlety for Microsoft Visual C/C++ style bit-field packing 33136 (e.g. -mms-bitfields) for targets that support it: When a 33137 bit-field is inserted into a packed record, the whole size of the 33138 underlying type is used by one or more same-size adjacent 33139 bit-fields (that is, if its long:3, 32 bits is used in the record, 33140 and any additional adjacent long bit-fields are packed into the 33141 same chunk of 32 bits. However, if the size changes, a new field 33142 of that size is allocated). 33143 33144 If both MS bit-fields and `__attribute__((packed))' are used, the 33145 latter will take precedence. If `__attribute__((packed))' is used 33146 on a single field when MS bit-fields are in use, it will take 33147 precedence for that field, but the alignment of the rest of the 33148 structure may affect its placement. 33149 33150 The weak pragma only works if `SUPPORTS_WEAK' and 33151 `ASM_WEAKEN_LABEL' are defined. If enabled it allows the creation 33152 of specifically named weak labels, optionally with a value. 33153 33154 -- Macro: HANDLE_PRAGMA_PACK_PUSH_POP 33155 Define this macro (to a value of 1) if you want to support the 33156 Win32 style pragmas `#pragma pack(push[,N])' and `#pragma 33157 pack(pop)'. The `pack(push,[N])' pragma specifies the maximum 33158 alignment (in bytes) of fields within a structure, in much the 33159 same way as the `__aligned__' and `__packed__' `__attribute__'s 33160 do. A pack value of zero resets the behavior to the default. 33161 Successive invocations of this pragma cause the previous values to 33162 be stacked, so that invocations of `#pragma pack(pop)' will return 33163 to the previous value. 33164 33165 -- Macro: HANDLE_PRAGMA_PACK_WITH_EXPANSION 33166 Define this macro, as well as `HANDLE_SYSV_PRAGMA', if macros 33167 should be expanded in the arguments of `#pragma pack'. 33168 33169 -- Macro: TARGET_DEFAULT_PACK_STRUCT 33170 If your target requires a structure packing default other than 0 33171 (meaning the machine default), define this macro to the necessary 33172 value (in bytes). This must be a value that would also be valid 33173 to use with `#pragma pack()' (that is, a small power of two). 33174 33175 -- Macro: HANDLE_PRAGMA_PUSH_POP_MACRO 33176 Define this macro if you want to support the Win32 style pragmas 33177 `#pragma push_macro(macro-name-as-string)' and `#pragma 33178 pop_macro(macro-name-as-string)'. The `#pragma push_macro( 33179 macro-name-as-string)' pragma saves the named macro and via 33180 `#pragma pop_macro(macro-name-as-string)' it will return to the 33181 previous value. 33182 33183 -- Macro: DOLLARS_IN_IDENTIFIERS 33184 Define this macro to control use of the character `$' in 33185 identifier names for the C family of languages. 0 means `$' is 33186 not allowed by default; 1 means it is allowed. 1 is the default; 33187 there is no need to define this macro in that case. 33188 33189 -- Macro: NO_DOLLAR_IN_LABEL 33190 Define this macro if the assembler does not accept the character 33191 `$' in label names. By default constructors and destructors in 33192 G++ have `$' in the identifiers. If this macro is defined, `.' is 33193 used instead. 33194 33195 -- Macro: NO_DOT_IN_LABEL 33196 Define this macro if the assembler does not accept the character 33197 `.' in label names. By default constructors and destructors in G++ 33198 have names that use `.'. If this macro is defined, these names 33199 are rewritten to avoid `.'. 33200 33201 -- Macro: INSN_SETS_ARE_DELAYED (INSN) 33202 Define this macro as a C expression that is nonzero if it is safe 33203 for the delay slot scheduler to place instructions in the delay 33204 slot of INSN, even if they appear to use a resource set or 33205 clobbered in INSN. INSN is always a `jump_insn' or an `insn'; GCC 33206 knows that every `call_insn' has this behavior. On machines where 33207 some `insn' or `jump_insn' is really a function call and hence has 33208 this behavior, you should define this macro. 33209 33210 You need not define this macro if it would always return zero. 33211 33212 -- Macro: INSN_REFERENCES_ARE_DELAYED (INSN) 33213 Define this macro as a C expression that is nonzero if it is safe 33214 for the delay slot scheduler to place instructions in the delay 33215 slot of INSN, even if they appear to set or clobber a resource 33216 referenced in INSN. INSN is always a `jump_insn' or an `insn'. 33217 On machines where some `insn' or `jump_insn' is really a function 33218 call and its operands are registers whose use is actually in the 33219 subroutine it calls, you should define this macro. Doing so 33220 allows the delay slot scheduler to move instructions which copy 33221 arguments into the argument registers into the delay slot of INSN. 33222 33223 You need not define this macro if it would always return zero. 33224 33225 -- Macro: MULTIPLE_SYMBOL_SPACES 33226 Define this macro as a C expression that is nonzero if, in some 33227 cases, global symbols from one translation unit may not be bound 33228 to undefined symbols in another translation unit without user 33229 intervention. For instance, under Microsoft Windows symbols must 33230 be explicitly imported from shared libraries (DLLs). 33231 33232 You need not define this macro if it would always evaluate to zero. 33233 33234 -- Target Hook: tree TARGET_MD_ASM_CLOBBERS (tree OUTPUTS, tree 33235 INPUTS, tree CLOBBERS) 33236 This target hook should add to CLOBBERS `STRING_CST' trees for any 33237 hard regs the port wishes to automatically clobber for an asm. It 33238 should return the result of the last `tree_cons' used to add a 33239 clobber. The OUTPUTS, INPUTS and CLOBBER lists are the 33240 corresponding parameters to the asm and may be inspected to avoid 33241 clobbering a register that is an input or output of the asm. You 33242 can use `tree_overlaps_hard_reg_set', declared in `tree.h', to test 33243 for overlap with regards to asm-declared registers. 33244 33245 -- Macro: MATH_LIBRARY 33246 Define this macro as a C string constant for the linker argument 33247 to link in the system math library, or `""' if the target does not 33248 have a separate math library. 33249 33250 You need only define this macro if the default of `"-lm"' is wrong. 33251 33252 -- Macro: LIBRARY_PATH_ENV 33253 Define this macro as a C string constant for the environment 33254 variable that specifies where the linker should look for libraries. 33255 33256 You need only define this macro if the default of `"LIBRARY_PATH"' 33257 is wrong. 33258 33259 -- Macro: TARGET_POSIX_IO 33260 Define this macro if the target supports the following POSIX file 33261 functions, access, mkdir and file locking with fcntl / F_SETLKW. 33262 Defining `TARGET_POSIX_IO' will enable the test coverage code to 33263 use file locking when exiting a program, which avoids race 33264 conditions if the program has forked. It will also create 33265 directories at run-time for cross-profiling. 33266 33267 -- Macro: MAX_CONDITIONAL_EXECUTE 33268 A C expression for the maximum number of instructions to execute 33269 via conditional execution instructions instead of a branch. A 33270 value of `BRANCH_COST'+1 is the default if the machine does not 33271 use cc0, and 1 if it does use cc0. 33272 33273 -- Macro: IFCVT_MODIFY_TESTS (CE_INFO, TRUE_EXPR, FALSE_EXPR) 33274 Used if the target needs to perform machine-dependent 33275 modifications on the conditionals used for turning basic blocks 33276 into conditionally executed code. CE_INFO points to a data 33277 structure, `struct ce_if_block', which contains information about 33278 the currently processed blocks. TRUE_EXPR and FALSE_EXPR are the 33279 tests that are used for converting the then-block and the 33280 else-block, respectively. Set either TRUE_EXPR or FALSE_EXPR to a 33281 null pointer if the tests cannot be converted. 33282 33283 -- Macro: IFCVT_MODIFY_MULTIPLE_TESTS (CE_INFO, BB, TRUE_EXPR, 33284 FALSE_EXPR) 33285 Like `IFCVT_MODIFY_TESTS', but used when converting more 33286 complicated if-statements into conditions combined by `and' and 33287 `or' operations. BB contains the basic block that contains the 33288 test that is currently being processed and about to be turned into 33289 a condition. 33290 33291 -- Macro: IFCVT_MODIFY_INSN (CE_INFO, PATTERN, INSN) 33292 A C expression to modify the PATTERN of an INSN that is to be 33293 converted to conditional execution format. CE_INFO points to a 33294 data structure, `struct ce_if_block', which contains information 33295 about the currently processed blocks. 33296 33297 -- Macro: IFCVT_MODIFY_FINAL (CE_INFO) 33298 A C expression to perform any final machine dependent 33299 modifications in converting code to conditional execution. The 33300 involved basic blocks can be found in the `struct ce_if_block' 33301 structure that is pointed to by CE_INFO. 33302 33303 -- Macro: IFCVT_MODIFY_CANCEL (CE_INFO) 33304 A C expression to cancel any machine dependent modifications in 33305 converting code to conditional execution. The involved basic 33306 blocks can be found in the `struct ce_if_block' structure that is 33307 pointed to by CE_INFO. 33308 33309 -- Macro: IFCVT_INIT_EXTRA_FIELDS (CE_INFO) 33310 A C expression to initialize any extra fields in a `struct 33311 ce_if_block' structure, which are defined by the 33312 `IFCVT_EXTRA_FIELDS' macro. 33313 33314 -- Macro: IFCVT_EXTRA_FIELDS 33315 If defined, it should expand to a set of field declarations that 33316 will be added to the `struct ce_if_block' structure. These should 33317 be initialized by the `IFCVT_INIT_EXTRA_FIELDS' macro. 33318 33319 -- Target Hook: void TARGET_MACHINE_DEPENDENT_REORG () 33320 If non-null, this hook performs a target-specific pass over the 33321 instruction stream. The compiler will run it at all optimization 33322 levels, just before the point at which it normally does 33323 delayed-branch scheduling. 33324 33325 The exact purpose of the hook varies from target to target. Some 33326 use it to do transformations that are necessary for correctness, 33327 such as laying out in-function constant pools or avoiding hardware 33328 hazards. Others use it as an opportunity to do some 33329 machine-dependent optimizations. 33330 33331 You need not implement the hook if it has nothing to do. The 33332 default definition is null. 33333 33334 -- Target Hook: void TARGET_INIT_BUILTINS () 33335 Define this hook if you have any machine-specific built-in 33336 functions that need to be defined. It should be a function that 33337 performs the necessary setup. 33338 33339 Machine specific built-in functions can be useful to expand 33340 special machine instructions that would otherwise not normally be 33341 generated because they have no equivalent in the source language 33342 (for example, SIMD vector instructions or prefetch instructions). 33343 33344 To create a built-in function, call the function 33345 `lang_hooks.builtin_function' which is defined by the language 33346 front end. You can use any type nodes set up by 33347 `build_common_tree_nodes' and `build_common_tree_nodes_2'; only 33348 language front ends that use those two functions will call 33349 `TARGET_INIT_BUILTINS'. 33350 33351 -- Target Hook: rtx TARGET_EXPAND_BUILTIN (tree EXP, rtx TARGET, rtx 33352 SUBTARGET, enum machine_mode MODE, int IGNORE) 33353 Expand a call to a machine specific built-in function that was set 33354 up by `TARGET_INIT_BUILTINS'. EXP is the expression for the 33355 function call; the result should go to TARGET if that is 33356 convenient, and have mode MODE if that is convenient. SUBTARGET 33357 may be used as the target for computing one of EXP's operands. 33358 IGNORE is nonzero if the value is to be ignored. This function 33359 should return the result of the call to the built-in function. 33360 33361 -- Target Hook: tree TARGET_RESOLVE_OVERLOADED_BUILTIN (tree FNDECL, 33362 tree ARGLIST) 33363 Select a replacement for a machine specific built-in function that 33364 was set up by `TARGET_INIT_BUILTINS'. This is done _before_ 33365 regular type checking, and so allows the target to implement a 33366 crude form of function overloading. FNDECL is the declaration of 33367 the built-in function. ARGLIST is the list of arguments passed to 33368 the built-in function. The result is a complete expression that 33369 implements the operation, usually another `CALL_EXPR'. 33370 33371 -- Target Hook: tree TARGET_FOLD_BUILTIN (tree FNDECL, tree ARGLIST, 33372 bool IGNORE) 33373 Fold a call to a machine specific built-in function that was set 33374 up by `TARGET_INIT_BUILTINS'. FNDECL is the declaration of the 33375 built-in function. ARGLIST is the list of arguments passed to the 33376 built-in function. The result is another tree containing a 33377 simplified expression for the call's result. If IGNORE is true 33378 the value will be ignored. 33379 33380 -- Target Hook: const char * TARGET_INVALID_WITHIN_DOLOOP (rtx INSN) 33381 Take an instruction in INSN and return NULL if it is valid within a 33382 low-overhead loop, otherwise return a string why doloop could not 33383 be applied. 33384 33385 Many targets use special registers for low-overhead looping. For 33386 any instruction that clobbers these this function should return a 33387 string indicating the reason why the doloop could not be applied. 33388 By default, the RTL loop optimizer does not use a present doloop 33389 pattern for loops containing function calls or branch on table 33390 instructions. 33391 33392 -- Macro: MD_CAN_REDIRECT_BRANCH (BRANCH1, BRANCH2) 33393 Take a branch insn in BRANCH1 and another in BRANCH2. Return true 33394 if redirecting BRANCH1 to the destination of BRANCH2 is possible. 33395 33396 On some targets, branches may have a limited range. Optimizing the 33397 filling of delay slots can result in branches being redirected, 33398 and this may in turn cause a branch offset to overflow. 33399 33400 -- Target Hook: bool TARGET_COMMUTATIVE_P (rtx X, OUTER_CODE) 33401 This target hook returns `true' if X is considered to be 33402 commutative. Usually, this is just COMMUTATIVE_P (X), but the HP 33403 PA doesn't consider PLUS to be commutative inside a MEM. 33404 OUTER_CODE is the rtx code of the enclosing rtl, if known, 33405 otherwise it is UNKNOWN. 33406 33407 -- Target Hook: rtx TARGET_ALLOCATE_INITIAL_VALUE (rtx HARD_REG) 33408 When the initial value of a hard register has been copied in a 33409 pseudo register, it is often not necessary to actually allocate 33410 another register to this pseudo register, because the original 33411 hard register or a stack slot it has been saved into can be used. 33412 `TARGET_ALLOCATE_INITIAL_VALUE' is called at the start of register 33413 allocation once for each hard register that had its initial value 33414 copied by using `get_func_hard_reg_initial_val' or 33415 `get_hard_reg_initial_val'. Possible values are `NULL_RTX', if 33416 you don't want to do any special allocation, a `REG' rtx--that 33417 would typically be the hard register itself, if it is known not to 33418 be clobbered--or a `MEM'. If you are returning a `MEM', this is 33419 only a hint for the allocator; it might decide to use another 33420 register anyways. You may use `current_function_leaf_function' in 33421 the hook, functions that use `REG_N_SETS', to determine if the hard 33422 register in question will not be clobbered. The default value of 33423 this hook is `NULL', which disables any special allocation. 33424 33425 -- Target Hook: int TARGET_UNSPEC_MAY_TRAP_P (const_rtx X, unsigned 33426 FLAGS) 33427 This target hook returns nonzero if X, an `unspec' or 33428 `unspec_volatile' operation, might cause a trap. Targets can use 33429 this hook to enhance precision of analysis for `unspec' and 33430 `unspec_volatile' operations. You may call `may_trap_p_1' to 33431 analyze inner elements of X in which case FLAGS should be passed 33432 along. 33433 33434 -- Target Hook: void TARGET_SET_CURRENT_FUNCTION (tree DECL) 33435 The compiler invokes this hook whenever it changes its current 33436 function context (`cfun'). You can define this function if the 33437 back end needs to perform any initialization or reset actions on a 33438 per-function basis. For example, it may be used to implement 33439 function attributes that affect register usage or code generation 33440 patterns. The argument DECL is the declaration for the new 33441 function context, and may be null to indicate that the compiler 33442 has left a function context and is returning to processing at the 33443 top level. The default hook function does nothing. 33444 33445 GCC sets `cfun' to a dummy function context during initialization 33446 of some parts of the back end. The hook function is not invoked 33447 in this situation; you need not worry about the hook being invoked 33448 recursively, or when the back end is in a partially-initialized 33449 state. 33450 33451 -- Macro: TARGET_OBJECT_SUFFIX 33452 Define this macro to be a C string representing the suffix for 33453 object files on your target machine. If you do not define this 33454 macro, GCC will use `.o' as the suffix for object files. 33455 33456 -- Macro: TARGET_EXECUTABLE_SUFFIX 33457 Define this macro to be a C string representing the suffix to be 33458 automatically added to executable files on your target machine. 33459 If you do not define this macro, GCC will use the null string as 33460 the suffix for executable files. 33461 33462 -- Macro: COLLECT_EXPORT_LIST 33463 If defined, `collect2' will scan the individual object files 33464 specified on its command line and create an export list for the 33465 linker. Define this macro for systems like AIX, where the linker 33466 discards object files that are not referenced from `main' and uses 33467 export lists. 33468 33469 -- Macro: MODIFY_JNI_METHOD_CALL (MDECL) 33470 Define this macro to a C expression representing a variant of the 33471 method call MDECL, if Java Native Interface (JNI) methods must be 33472 invoked differently from other methods on your target. For 33473 example, on 32-bit Microsoft Windows, JNI methods must be invoked 33474 using the `stdcall' calling convention and this macro is then 33475 defined as this expression: 33476 33477 build_type_attribute_variant (MDECL, 33478 build_tree_list 33479 (get_identifier ("stdcall"), 33480 NULL)) 33481 33482 -- Target Hook: bool TARGET_CANNOT_MODIFY_JUMPS_P (void) 33483 This target hook returns `true' past the point in which new jump 33484 instructions could be created. On machines that require a 33485 register for every jump such as the SHmedia ISA of SH5, this point 33486 would typically be reload, so this target hook should be defined 33487 to a function such as: 33488 33489 static bool 33490 cannot_modify_jumps_past_reload_p () 33491 { 33492 return (reload_completed || reload_in_progress); 33493 } 33494 33495 -- Target Hook: int TARGET_BRANCH_TARGET_REGISTER_CLASS (void) 33496 This target hook returns a register class for which branch target 33497 register optimizations should be applied. All registers in this 33498 class should be usable interchangeably. After reload, registers 33499 in this class will be re-allocated and loads will be hoisted out 33500 of loops and be subjected to inter-block scheduling. 33501 33502 -- Target Hook: bool TARGET_BRANCH_TARGET_REGISTER_CALLEE_SAVED (bool 33503 AFTER_PROLOGUE_EPILOGUE_GEN) 33504 Branch target register optimization will by default exclude 33505 callee-saved registers that are not already live during the 33506 current function; if this target hook returns true, they will be 33507 included. The target code must than make sure that all target 33508 registers in the class returned by 33509 `TARGET_BRANCH_TARGET_REGISTER_CLASS' that might need saving are 33510 saved. AFTER_PROLOGUE_EPILOGUE_GEN indicates if prologues and 33511 epilogues have already been generated. Note, even if you only 33512 return true when AFTER_PROLOGUE_EPILOGUE_GEN is false, you still 33513 are likely to have to make special provisions in 33514 `INITIAL_ELIMINATION_OFFSET' to reserve space for caller-saved 33515 target registers. 33516 33517 -- Target Hook: bool TARGET_HAVE_CONDITIONAL_EXECUTION (void) 33518 This target hook returns true if the target supports conditional 33519 execution. This target hook is required only when the target has 33520 several different modes and they have different conditional 33521 execution capability, such as ARM. 33522 33523 -- Macro: POWI_MAX_MULTS 33524 If defined, this macro is interpreted as a signed integer C 33525 expression that specifies the maximum number of floating point 33526 multiplications that should be emitted when expanding 33527 exponentiation by an integer constant inline. When this value is 33528 defined, exponentiation requiring more than this number of 33529 multiplications is implemented by calling the system library's 33530 `pow', `powf' or `powl' routines. The default value places no 33531 upper bound on the multiplication count. 33532 33533 -- Macro: void TARGET_EXTRA_INCLUDES (const char *SYSROOT, const char 33534 *IPREFIX, int STDINC) 33535 This target hook should register any extra include files for the 33536 target. The parameter STDINC indicates if normal include files 33537 are present. The parameter SYSROOT is the system root directory. 33538 The parameter IPREFIX is the prefix for the gcc directory. 33539 33540 -- Macro: void TARGET_EXTRA_PRE_INCLUDES (const char *SYSROOT, const 33541 char *IPREFIX, int STDINC) 33542 This target hook should register any extra include files for the 33543 target before any standard headers. The parameter STDINC 33544 indicates if normal include files are present. The parameter 33545 SYSROOT is the system root directory. The parameter IPREFIX is 33546 the prefix for the gcc directory. 33547 33548 -- Macro: void TARGET_OPTF (char *PATH) 33549 This target hook should register special include paths for the 33550 target. The parameter PATH is the include to register. On Darwin 33551 systems, this is used for Framework includes, which have semantics 33552 that are different from `-I'. 33553 33554 -- Target Hook: bool TARGET_USE_LOCAL_THUNK_ALIAS_P (tree FNDECL) 33555 This target hook returns `true' if it is safe to use a local alias 33556 for a virtual function FNDECL when constructing thunks, `false' 33557 otherwise. By default, the hook returns `true' for all functions, 33558 if a target supports aliases (i.e. defines `ASM_OUTPUT_DEF'), 33559 `false' otherwise, 33560 33561 -- Macro: TARGET_FORMAT_TYPES 33562 If defined, this macro is the name of a global variable containing 33563 target-specific format checking information for the `-Wformat' 33564 option. The default is to have no target-specific format checks. 33565 33566 -- Macro: TARGET_N_FORMAT_TYPES 33567 If defined, this macro is the number of entries in 33568 `TARGET_FORMAT_TYPES'. 33569 33570 -- Macro: TARGET_OVERRIDES_FORMAT_ATTRIBUTES 33571 If defined, this macro is the name of a global variable containing 33572 target-specific format overrides for the `-Wformat' option. The 33573 default is to have no target-specific format overrides. If defined, 33574 `TARGET_FORMAT_TYPES' must be defined, too. 33575 33576 -- Macro: TARGET_OVERRIDES_FORMAT_ATTRIBUTES_COUNT 33577 If defined, this macro specifies the number of entries in 33578 `TARGET_OVERRIDES_FORMAT_ATTRIBUTES'. 33579 33580 -- Macro: TARGET_OVERRIDES_FORMAT_INIT 33581 If defined, this macro specifies the optional initialization 33582 routine for target specific customizations of the system printf 33583 and scanf formatter settings. 33584 33585 -- Target Hook: bool TARGET_RELAXED_ORDERING 33586 If set to `true', means that the target's memory model does not 33587 guarantee that loads which do not depend on one another will access 33588 main memory in the order of the instruction stream; if ordering is 33589 important, an explicit memory barrier must be used. This is true 33590 of many recent processors which implement a policy of "relaxed," 33591 "weak," or "release" memory consistency, such as Alpha, PowerPC, 33592 and ia64. The default is `false'. 33593 33594 -- Target Hook: const char *TARGET_INVALID_ARG_FOR_UNPROTOTYPED_FN 33595 (tree TYPELIST, tree FUNCDECL, tree VAL) 33596 If defined, this macro returns the diagnostic message when it is 33597 illegal to pass argument VAL to function FUNCDECL with prototype 33598 TYPELIST. 33599 33600 -- Target Hook: const char * TARGET_INVALID_CONVERSION (tree FROMTYPE, 33601 tree TOTYPE) 33602 If defined, this macro returns the diagnostic message when it is 33603 invalid to convert from FROMTYPE to TOTYPE, or `NULL' if validity 33604 should be determined by the front end. 33605 33606 -- Target Hook: const char * TARGET_INVALID_UNARY_OP (int OP, tree 33607 TYPE) 33608 If defined, this macro returns the diagnostic message when it is 33609 invalid to apply operation OP (where unary plus is denoted by 33610 `CONVERT_EXPR') to an operand of type TYPE, or `NULL' if validity 33611 should be determined by the front end. 33612 33613 -- Target Hook: const char * TARGET_INVALID_BINARY_OP (int OP, tree 33614 TYPE1, tree TYPE2) 33615 If defined, this macro returns the diagnostic message when it is 33616 invalid to apply operation OP to operands of types TYPE1 and 33617 TYPE2, or `NULL' if validity should be determined by the front end. 33618 33619 -- Macro: TARGET_USE_JCR_SECTION 33620 This macro determines whether to use the JCR section to register 33621 Java classes. By default, TARGET_USE_JCR_SECTION is defined to 1 33622 if both SUPPORTS_WEAK and TARGET_HAVE_NAMED_SECTIONS are true, 33623 else 0. 33624 33625 -- Macro: OBJC_JBLEN 33626 This macro determines the size of the objective C jump buffer for 33627 the NeXT runtime. By default, OBJC_JBLEN is defined to an 33628 innocuous value. 33629 33630 -- Macro: LIBGCC2_UNWIND_ATTRIBUTE 33631 Define this macro if any target-specific attributes need to be 33632 attached to the functions in `libgcc' that provide low-level 33633 support for call stack unwinding. It is used in declarations in 33634 `unwind-generic.h' and the associated definitions of those 33635 functions. 33636 33637 -- Target Hook: void TARGET_UPDATE_STACK_BOUNDARY (void) 33638 Define this macro to update the current function stack boundary if 33639 necessary. 33640 33641 -- Target Hook: rtx TARGET_GET_DRAP_RTX (void) 33642 Define this macro to an rtx for Dynamic Realign Argument Pointer 33643 if a different argument pointer register is needed to access the 33644 function's argument list when stack is aligned. 33645 33646 -- Target Hook: bool TARGET_ALLOCATE_STACK_SLOTS_FOR_ARGS (void) 33647 When optimization is disabled, this hook indicates whether or not 33648 arguments should be allocated to stack slots. Normally, GCC 33649 allocates stacks slots for arguments when not optimizing in order 33650 to make debugging easier. However, when a function is declared 33651 with `__attribute__((naked))', there is no stack frame, and the 33652 compiler cannot safely move arguments from the registers in which 33653 they are passed to the stack. Therefore, this hook should return 33654 true in general, but false for naked functions. The default 33655 implementation always returns true. 33656 33657 33658 File: gccint.info, Node: Host Config, Next: Fragments, Prev: Target Macros, Up: Top 33659 33660 18 Host Configuration 33661 ********************* 33662 33663 Most details about the machine and system on which the compiler is 33664 actually running are detected by the `configure' script. Some things 33665 are impossible for `configure' to detect; these are described in two 33666 ways, either by macros defined in a file named `xm-MACHINE.h' or by 33667 hook functions in the file specified by the OUT_HOST_HOOK_OBJ variable 33668 in `config.gcc'. (The intention is that very few hosts will need a 33669 header file but nearly every fully supported host will need to override 33670 some hooks.) 33671 33672 If you need to define only a few macros, and they have simple 33673 definitions, consider using the `xm_defines' variable in your 33674 `config.gcc' entry instead of creating a host configuration header. 33675 *Note System Config::. 33676 33677 * Menu: 33678 33679 * Host Common:: Things every host probably needs implemented. 33680 * Filesystem:: Your host can't have the letter `a' in filenames? 33681 * Host Misc:: Rare configuration options for hosts. 33682 33683 33684 File: gccint.info, Node: Host Common, Next: Filesystem, Up: Host Config 33685 33686 18.1 Host Common 33687 ================ 33688 33689 Some things are just not portable, even between similar operating 33690 systems, and are too difficult for autoconf to detect. They get 33691 implemented using hook functions in the file specified by the 33692 HOST_HOOK_OBJ variable in `config.gcc'. 33693 33694 -- Host Hook: void HOST_HOOKS_EXTRA_SIGNALS (void) 33695 This host hook is used to set up handling for extra signals. The 33696 most common thing to do in this hook is to detect stack overflow. 33697 33698 -- Host Hook: void * HOST_HOOKS_GT_PCH_GET_ADDRESS (size_t SIZE, int 33699 FD) 33700 This host hook returns the address of some space that is likely to 33701 be free in some subsequent invocation of the compiler. We intend 33702 to load the PCH data at this address such that the data need not 33703 be relocated. The area should be able to hold SIZE bytes. If the 33704 host uses `mmap', FD is an open file descriptor that can be used 33705 for probing. 33706 33707 -- Host Hook: int HOST_HOOKS_GT_PCH_USE_ADDRESS (void * ADDRESS, 33708 size_t SIZE, int FD, size_t OFFSET) 33709 This host hook is called when a PCH file is about to be loaded. 33710 We want to load SIZE bytes from FD at OFFSET into memory at 33711 ADDRESS. The given address will be the result of a previous 33712 invocation of `HOST_HOOKS_GT_PCH_GET_ADDRESS'. Return -1 if we 33713 couldn't allocate SIZE bytes at ADDRESS. Return 0 if the memory 33714 is allocated but the data is not loaded. Return 1 if the hook has 33715 performed everything. 33716 33717 If the implementation uses reserved address space, free any 33718 reserved space beyond SIZE, regardless of the return value. If no 33719 PCH will be loaded, this hook may be called with SIZE zero, in 33720 which case all reserved address space should be freed. 33721 33722 Do not try to handle values of ADDRESS that could not have been 33723 returned by this executable; just return -1. Such values usually 33724 indicate an out-of-date PCH file (built by some other GCC 33725 executable), and such a PCH file won't work. 33726 33727 -- Host Hook: size_t HOST_HOOKS_GT_PCH_ALLOC_GRANULARITY (void); 33728 This host hook returns the alignment required for allocating 33729 virtual memory. Usually this is the same as getpagesize, but on 33730 some hosts the alignment for reserving memory differs from the 33731 pagesize for committing memory. 33732 33733 33734 File: gccint.info, Node: Filesystem, Next: Host Misc, Prev: Host Common, Up: Host Config 33735 33736 18.2 Host Filesystem 33737 ==================== 33738 33739 GCC needs to know a number of things about the semantics of the host 33740 machine's filesystem. Filesystems with Unix and MS-DOS semantics are 33741 automatically detected. For other systems, you can define the 33742 following macros in `xm-MACHINE.h'. 33743 33744 `HAVE_DOS_BASED_FILE_SYSTEM' 33745 This macro is automatically defined by `system.h' if the host file 33746 system obeys the semantics defined by MS-DOS instead of Unix. DOS 33747 file systems are case insensitive, file specifications may begin 33748 with a drive letter, and both forward slash and backslash (`/' and 33749 `\') are directory separators. 33750 33751 `DIR_SEPARATOR' 33752 `DIR_SEPARATOR_2' 33753 If defined, these macros expand to character constants specifying 33754 separators for directory names within a file specification. 33755 `system.h' will automatically give them appropriate values on Unix 33756 and MS-DOS file systems. If your file system is neither of these, 33757 define one or both appropriately in `xm-MACHINE.h'. 33758 33759 However, operating systems like VMS, where constructing a pathname 33760 is more complicated than just stringing together directory names 33761 separated by a special character, should not define either of these 33762 macros. 33763 33764 `PATH_SEPARATOR' 33765 If defined, this macro should expand to a character constant 33766 specifying the separator for elements of search paths. The default 33767 value is a colon (`:'). DOS-based systems usually, but not 33768 always, use semicolon (`;'). 33769 33770 `VMS' 33771 Define this macro if the host system is VMS. 33772 33773 `HOST_OBJECT_SUFFIX' 33774 Define this macro to be a C string representing the suffix for 33775 object files on your host machine. If you do not define this 33776 macro, GCC will use `.o' as the suffix for object files. 33777 33778 `HOST_EXECUTABLE_SUFFIX' 33779 Define this macro to be a C string representing the suffix for 33780 executable files on your host machine. If you do not define this 33781 macro, GCC will use the null string as the suffix for executable 33782 files. 33783 33784 `HOST_BIT_BUCKET' 33785 A pathname defined by the host operating system, which can be 33786 opened as a file and written to, but all the information written 33787 is discarded. This is commonly known as a "bit bucket" or "null 33788 device". If you do not define this macro, GCC will use 33789 `/dev/null' as the bit bucket. If the host does not support a bit 33790 bucket, define this macro to an invalid filename. 33791 33792 `UPDATE_PATH_HOST_CANONICALIZE (PATH)' 33793 If defined, a C statement (sans semicolon) that performs 33794 host-dependent canonicalization when a path used in a compilation 33795 driver or preprocessor is canonicalized. PATH is a malloc-ed path 33796 to be canonicalized. If the C statement does canonicalize PATH 33797 into a different buffer, the old path should be freed and the new 33798 buffer should have been allocated with malloc. 33799 33800 `DUMPFILE_FORMAT' 33801 Define this macro to be a C string representing the format to use 33802 for constructing the index part of debugging dump file names. The 33803 resultant string must fit in fifteen bytes. The full filename 33804 will be the concatenation of: the prefix of the assembler file 33805 name, the string resulting from applying this format to an index 33806 number, and a string unique to each dump file kind, e.g. `rtl'. 33807 33808 If you do not define this macro, GCC will use `.%02d.'. You should 33809 define this macro if using the default will create an invalid file 33810 name. 33811 33812 `DELETE_IF_ORDINARY' 33813 Define this macro to be a C statement (sans semicolon) that 33814 performs host-dependent removal of ordinary temp files in the 33815 compilation driver. 33816 33817 If you do not define this macro, GCC will use the default version. 33818 You should define this macro if the default version does not 33819 reliably remove the temp file as, for example, on VMS which allows 33820 multiple versions of a file. 33821 33822 `HOST_LACKS_INODE_NUMBERS' 33823 Define this macro if the host filesystem does not report 33824 meaningful inode numbers in struct stat. 33825 33826 33827 File: gccint.info, Node: Host Misc, Prev: Filesystem, Up: Host Config 33828 33829 18.3 Host Misc 33830 ============== 33831 33832 `FATAL_EXIT_CODE' 33833 A C expression for the status code to be returned when the compiler 33834 exits after serious errors. The default is the system-provided 33835 macro `EXIT_FAILURE', or `1' if the system doesn't define that 33836 macro. Define this macro only if these defaults are incorrect. 33837 33838 `SUCCESS_EXIT_CODE' 33839 A C expression for the status code to be returned when the compiler 33840 exits without serious errors. (Warnings are not serious errors.) 33841 The default is the system-provided macro `EXIT_SUCCESS', or `0' if 33842 the system doesn't define that macro. Define this macro only if 33843 these defaults are incorrect. 33844 33845 `USE_C_ALLOCA' 33846 Define this macro if GCC should use the C implementation of 33847 `alloca' provided by `libiberty.a'. This only affects how some 33848 parts of the compiler itself allocate memory. It does not change 33849 code generation. 33850 33851 When GCC is built with a compiler other than itself, the C `alloca' 33852 is always used. This is because most other implementations have 33853 serious bugs. You should define this macro only on a system where 33854 no stack-based `alloca' can possibly work. For instance, if a 33855 system has a small limit on the size of the stack, GCC's builtin 33856 `alloca' will not work reliably. 33857 33858 `COLLECT2_HOST_INITIALIZATION' 33859 If defined, a C statement (sans semicolon) that performs 33860 host-dependent initialization when `collect2' is being initialized. 33861 33862 `GCC_DRIVER_HOST_INITIALIZATION' 33863 If defined, a C statement (sans semicolon) that performs 33864 host-dependent initialization when a compilation driver is being 33865 initialized. 33866 33867 `HOST_LONG_LONG_FORMAT' 33868 If defined, the string used to indicate an argument of type `long 33869 long' to functions like `printf'. The default value is `"ll"'. 33870 33871 In addition, if `configure' generates an incorrect definition of any 33872 of the macros in `auto-host.h', you can override that definition in a 33873 host configuration header. If you need to do this, first see if it is 33874 possible to fix `configure'. 33875 33876 33877 File: gccint.info, Node: Fragments, Next: Collect2, Prev: Host Config, Up: Top 33878 33879 19 Makefile Fragments 33880 ********************* 33881 33882 When you configure GCC using the `configure' script, it will construct 33883 the file `Makefile' from the template file `Makefile.in'. When it does 33884 this, it can incorporate makefile fragments from the `config' 33885 directory. These are used to set Makefile parameters that are not 33886 amenable to being calculated by autoconf. The list of fragments to 33887 incorporate is set by `config.gcc' (and occasionally `config.build' and 33888 `config.host'); *Note System Config::. 33889 33890 Fragments are named either `t-TARGET' or `x-HOST', depending on 33891 whether they are relevant to configuring GCC to produce code for a 33892 particular target, or to configuring GCC to run on a particular host. 33893 Here TARGET and HOST are mnemonics which usually have some relationship 33894 to the canonical system name, but no formal connection. 33895 33896 If these files do not exist, it means nothing needs to be added for a 33897 given target or host. Most targets need a few `t-TARGET' fragments, 33898 but needing `x-HOST' fragments is rare. 33899 33900 * Menu: 33901 33902 * Target Fragment:: Writing `t-TARGET' files. 33903 * Host Fragment:: Writing `x-HOST' files. 33904 33905 33906 File: gccint.info, Node: Target Fragment, Next: Host Fragment, Up: Fragments 33907 33908 19.1 Target Makefile Fragments 33909 ============================== 33910 33911 Target makefile fragments can set these Makefile variables. 33912 33913 `LIBGCC2_CFLAGS' 33914 Compiler flags to use when compiling `libgcc2.c'. 33915 33916 `LIB2FUNCS_EXTRA' 33917 A list of source file names to be compiled or assembled and 33918 inserted into `libgcc.a'. 33919 33920 `Floating Point Emulation' 33921 To have GCC include software floating point libraries in `libgcc.a' 33922 define `FPBIT' and `DPBIT' along with a few rules as follows: 33923 # We want fine grained libraries, so use the new code 33924 # to build the floating point emulation libraries. 33925 FPBIT = fp-bit.c 33926 DPBIT = dp-bit.c 33927 33928 33929 fp-bit.c: $(srcdir)/config/fp-bit.c 33930 echo '#define FLOAT' > fp-bit.c 33931 cat $(srcdir)/config/fp-bit.c >> fp-bit.c 33932 33933 dp-bit.c: $(srcdir)/config/fp-bit.c 33934 cat $(srcdir)/config/fp-bit.c > dp-bit.c 33935 33936 You may need to provide additional #defines at the beginning of 33937 `fp-bit.c' and `dp-bit.c' to control target endianness and other 33938 options. 33939 33940 `CRTSTUFF_T_CFLAGS' 33941 Special flags used when compiling `crtstuff.c'. *Note 33942 Initialization::. 33943 33944 `CRTSTUFF_T_CFLAGS_S' 33945 Special flags used when compiling `crtstuff.c' for shared linking. 33946 Used if you use `crtbeginS.o' and `crtendS.o' in `EXTRA-PARTS'. 33947 *Note Initialization::. 33948 33949 `MULTILIB_OPTIONS' 33950 For some targets, invoking GCC in different ways produces objects 33951 that can not be linked together. For example, for some targets GCC 33952 produces both big and little endian code. For these targets, you 33953 must arrange for multiple versions of `libgcc.a' to be compiled, 33954 one for each set of incompatible options. When GCC invokes the 33955 linker, it arranges to link in the right version of `libgcc.a', 33956 based on the command line options used. 33957 33958 The `MULTILIB_OPTIONS' macro lists the set of options for which 33959 special versions of `libgcc.a' must be built. Write options that 33960 are mutually incompatible side by side, separated by a slash. 33961 Write options that may be used together separated by a space. The 33962 build procedure will build all combinations of compatible options. 33963 33964 For example, if you set `MULTILIB_OPTIONS' to `m68000/m68020 33965 msoft-float', `Makefile' will build special versions of `libgcc.a' 33966 using the following sets of options: `-m68000', `-m68020', 33967 `-msoft-float', `-m68000 -msoft-float', and `-m68020 -msoft-float'. 33968 33969 `MULTILIB_DIRNAMES' 33970 If `MULTILIB_OPTIONS' is used, this variable specifies the 33971 directory names that should be used to hold the various libraries. 33972 Write one element in `MULTILIB_DIRNAMES' for each element in 33973 `MULTILIB_OPTIONS'. If `MULTILIB_DIRNAMES' is not used, the 33974 default value will be `MULTILIB_OPTIONS', with all slashes treated 33975 as spaces. 33976 33977 For example, if `MULTILIB_OPTIONS' is set to `m68000/m68020 33978 msoft-float', then the default value of `MULTILIB_DIRNAMES' is 33979 `m68000 m68020 msoft-float'. You may specify a different value if 33980 you desire a different set of directory names. 33981 33982 `MULTILIB_MATCHES' 33983 Sometimes the same option may be written in two different ways. 33984 If an option is listed in `MULTILIB_OPTIONS', GCC needs to know 33985 about any synonyms. In that case, set `MULTILIB_MATCHES' to a 33986 list of items of the form `option=option' to describe all relevant 33987 synonyms. For example, `m68000=mc68000 m68020=mc68020'. 33988 33989 `MULTILIB_EXCEPTIONS' 33990 Sometimes when there are multiple sets of `MULTILIB_OPTIONS' being 33991 specified, there are combinations that should not be built. In 33992 that case, set `MULTILIB_EXCEPTIONS' to be all of the switch 33993 exceptions in shell case syntax that should not be built. 33994 33995 For example the ARM processor cannot execute both hardware floating 33996 point instructions and the reduced size THUMB instructions at the 33997 same time, so there is no need to build libraries with both of 33998 these options enabled. Therefore `MULTILIB_EXCEPTIONS' is set to: 33999 *mthumb/*mhard-float* 34000 34001 `MULTILIB_EXTRA_OPTS' 34002 Sometimes it is desirable that when building multiple versions of 34003 `libgcc.a' certain options should always be passed on to the 34004 compiler. In that case, set `MULTILIB_EXTRA_OPTS' to be the list 34005 of options to be used for all builds. If you set this, you should 34006 probably set `CRTSTUFF_T_CFLAGS' to a dash followed by it. 34007 34008 `NATIVE_SYSTEM_HEADER_DIR' 34009 If the default location for system headers is not `/usr/include', 34010 you must set this to the directory containing the headers. This 34011 value should match the value of the `SYSTEM_INCLUDE_DIR' macro. 34012 34013 `SPECS' 34014 Unfortunately, setting `MULTILIB_EXTRA_OPTS' is not enough, since 34015 it does not affect the build of target libraries, at least not the 34016 build of the default multilib. One possible work-around is to use 34017 `DRIVER_SELF_SPECS' to bring options from the `specs' file as if 34018 they had been passed in the compiler driver command line. 34019 However, you don't want to be adding these options after the 34020 toolchain is installed, so you can instead tweak the `specs' file 34021 that will be used during the toolchain build, while you still 34022 install the original, built-in `specs'. The trick is to set 34023 `SPECS' to some other filename (say `specs.install'), that will 34024 then be created out of the built-in specs, and introduce a 34025 `Makefile' rule to generate the `specs' file that's going to be 34026 used at build time out of your `specs.install'. 34027 34028 `T_CFLAGS' 34029 These are extra flags to pass to the C compiler. They are used 34030 both when building GCC, and when compiling things with the 34031 just-built GCC. This variable is deprecated and should not be 34032 used. 34033 34034 34035 File: gccint.info, Node: Host Fragment, Prev: Target Fragment, Up: Fragments 34036 34037 19.2 Host Makefile Fragments 34038 ============================ 34039 34040 The use of `x-HOST' fragments is discouraged. You should only use it 34041 for makefile dependencies. 34042 34043 34044 File: gccint.info, Node: Collect2, Next: Header Dirs, Prev: Fragments, Up: Top 34045 34046 20 `collect2' 34047 ************* 34048 34049 GCC uses a utility called `collect2' on nearly all systems to arrange 34050 to call various initialization functions at start time. 34051 34052 The program `collect2' works by linking the program once and looking 34053 through the linker output file for symbols with particular names 34054 indicating they are constructor functions. If it finds any, it creates 34055 a new temporary `.c' file containing a table of them, compiles it, and 34056 links the program a second time including that file. 34057 34058 The actual calls to the constructors are carried out by a subroutine 34059 called `__main', which is called (automatically) at the beginning of 34060 the body of `main' (provided `main' was compiled with GNU CC). Calling 34061 `__main' is necessary, even when compiling C code, to allow linking C 34062 and C++ object code together. (If you use `-nostdlib', you get an 34063 unresolved reference to `__main', since it's defined in the standard 34064 GCC library. Include `-lgcc' at the end of your compiler command line 34065 to resolve this reference.) 34066 34067 The program `collect2' is installed as `ld' in the directory where the 34068 passes of the compiler are installed. When `collect2' needs to find 34069 the _real_ `ld', it tries the following file names: 34070 34071 * `real-ld' in the directories listed in the compiler's search 34072 directories. 34073 34074 * `real-ld' in the directories listed in the environment variable 34075 `PATH'. 34076 34077 * The file specified in the `REAL_LD_FILE_NAME' configuration macro, 34078 if specified. 34079 34080 * `ld' in the compiler's search directories, except that `collect2' 34081 will not execute itself recursively. 34082 34083 * `ld' in `PATH'. 34084 34085 "The compiler's search directories" means all the directories where 34086 `gcc' searches for passes of the compiler. This includes directories 34087 that you specify with `-B'. 34088 34089 Cross-compilers search a little differently: 34090 34091 * `real-ld' in the compiler's search directories. 34092 34093 * `TARGET-real-ld' in `PATH'. 34094 34095 * The file specified in the `REAL_LD_FILE_NAME' configuration macro, 34096 if specified. 34097 34098 * `ld' in the compiler's search directories. 34099 34100 * `TARGET-ld' in `PATH'. 34101 34102 `collect2' explicitly avoids running `ld' using the file name under 34103 which `collect2' itself was invoked. In fact, it remembers up a list 34104 of such names--in case one copy of `collect2' finds another copy (or 34105 version) of `collect2' installed as `ld' in a second place in the 34106 search path. 34107 34108 `collect2' searches for the utilities `nm' and `strip' using the same 34109 algorithm as above for `ld'. 34110 34111 34112 File: gccint.info, Node: Header Dirs, Next: Type Information, Prev: Collect2, Up: Top 34113 34114 21 Standard Header File Directories 34115 *********************************** 34116 34117 `GCC_INCLUDE_DIR' means the same thing for native and cross. It is 34118 where GCC stores its private include files, and also where GCC stores 34119 the fixed include files. A cross compiled GCC runs `fixincludes' on 34120 the header files in `$(tooldir)/include'. (If the cross compilation 34121 header files need to be fixed, they must be installed before GCC is 34122 built. If the cross compilation header files are already suitable for 34123 GCC, nothing special need be done). 34124 34125 `GPLUSPLUS_INCLUDE_DIR' means the same thing for native and cross. It 34126 is where `g++' looks first for header files. The C++ library installs 34127 only target independent header files in that directory. 34128 34129 `LOCAL_INCLUDE_DIR' is used only by native compilers. GCC doesn't 34130 install anything there. It is normally `/usr/local/include'. This is 34131 where local additions to a packaged system should place header files. 34132 34133 `CROSS_INCLUDE_DIR' is used only by cross compilers. GCC doesn't 34134 install anything there. 34135 34136 `TOOL_INCLUDE_DIR' is used for both native and cross compilers. It is 34137 the place for other packages to install header files that GCC will use. 34138 For a cross-compiler, this is the equivalent of `/usr/include'. When 34139 you build a cross-compiler, `fixincludes' processes any header files in 34140 this directory. 34141 34142 34143 File: gccint.info, Node: Type Information, Next: Plugins, Prev: Header Dirs, Up: Top 34144 34145 22 Memory Management and Type Information 34146 ***************************************** 34147 34148 GCC uses some fairly sophisticated memory management techniques, which 34149 involve determining information about GCC's data structures from GCC's 34150 source code and using this information to perform garbage collection and 34151 implement precompiled headers. 34152 34153 A full C parser would be too complicated for this task, so a limited 34154 subset of C is interpreted and special markers are used to determine 34155 what parts of the source to look at. All `struct' and `union' 34156 declarations that define data structures that are allocated under 34157 control of the garbage collector must be marked. All global variables 34158 that hold pointers to garbage-collected memory must also be marked. 34159 Finally, all global variables that need to be saved and restored by a 34160 precompiled header must be marked. (The precompiled header mechanism 34161 can only save static variables if they're scalar. Complex data 34162 structures must be allocated in garbage-collected memory to be saved in 34163 a precompiled header.) 34164 34165 The full format of a marker is 34166 GTY (([OPTION] [(PARAM)], [OPTION] [(PARAM)] ...)) 34167 but in most cases no options are needed. The outer double parentheses 34168 are still necessary, though: `GTY(())'. Markers can appear: 34169 34170 * In a structure definition, before the open brace; 34171 34172 * In a global variable declaration, after the keyword `static' or 34173 `extern'; and 34174 34175 * In a structure field definition, before the name of the field. 34176 34177 Here are some examples of marking simple data structures and globals. 34178 34179 struct TAG GTY(()) 34180 { 34181 FIELDS... 34182 }; 34183 34184 typedef struct TAG GTY(()) 34185 { 34186 FIELDS... 34187 } *TYPENAME; 34188 34189 static GTY(()) struct TAG *LIST; /* points to GC memory */ 34190 static GTY(()) int COUNTER; /* save counter in a PCH */ 34191 34192 The parser understands simple typedefs such as `typedef struct TAG 34193 *NAME;' and `typedef int NAME;'. These don't need to be marked. 34194 34195 * Menu: 34196 34197 * GTY Options:: What goes inside a `GTY(())'. 34198 * GGC Roots:: Making global variables GGC roots. 34199 * Files:: How the generated files work. 34200 * Invoking the garbage collector:: How to invoke the garbage collector. 34201 34202 34203 File: gccint.info, Node: GTY Options, Next: GGC Roots, Up: Type Information 34204 34205 22.1 The Inside of a `GTY(())' 34206 ============================== 34207 34208 Sometimes the C code is not enough to fully describe the type 34209 structure. Extra information can be provided with `GTY' options and 34210 additional markers. Some options take a parameter, which may be either 34211 a string or a type name, depending on the parameter. If an option 34212 takes no parameter, it is acceptable either to omit the parameter 34213 entirely, or to provide an empty string as a parameter. For example, 34214 `GTY ((skip))' and `GTY ((skip ("")))' are equivalent. 34215 34216 When the parameter is a string, often it is a fragment of C code. Four 34217 special escapes may be used in these strings, to refer to pieces of the 34218 data structure being marked: 34219 34220 `%h' 34221 The current structure. 34222 34223 `%1' 34224 The structure that immediately contains the current structure. 34225 34226 `%0' 34227 The outermost structure that contains the current structure. 34228 34229 `%a' 34230 A partial expression of the form `[i1][i2]...' that indexes the 34231 array item currently being marked. 34232 34233 For instance, suppose that you have a structure of the form 34234 struct A { 34235 ... 34236 }; 34237 struct B { 34238 struct A foo[12]; 34239 }; 34240 and `b' is a variable of type `struct B'. When marking `b.foo[11]', 34241 `%h' would expand to `b.foo[11]', `%0' and `%1' would both expand to 34242 `b', and `%a' would expand to `[11]'. 34243 34244 As in ordinary C, adjacent strings will be concatenated; this is 34245 helpful when you have a complicated expression. 34246 GTY ((chain_next ("TREE_CODE (&%h.generic) == INTEGER_TYPE" 34247 " ? TYPE_NEXT_VARIANT (&%h.generic)" 34248 " : TREE_CHAIN (&%h.generic)"))) 34249 34250 The available options are: 34251 34252 `length ("EXPRESSION")' 34253 There are two places the type machinery will need to be explicitly 34254 told the length of an array. The first case is when a structure 34255 ends in a variable-length array, like this: 34256 struct rtvec_def GTY(()) { 34257 int num_elem; /* number of elements */ 34258 rtx GTY ((length ("%h.num_elem"))) elem[1]; 34259 }; 34260 34261 In this case, the `length' option is used to override the specified 34262 array length (which should usually be `1'). The parameter of the 34263 option is a fragment of C code that calculates the length. 34264 34265 The second case is when a structure or a global variable contains a 34266 pointer to an array, like this: 34267 tree * 34268 GTY ((length ("%h.regno_pointer_align_length"))) regno_decl; 34269 In this case, `regno_decl' has been allocated by writing something 34270 like 34271 x->regno_decl = 34272 ggc_alloc (x->regno_pointer_align_length * sizeof (tree)); 34273 and the `length' provides the length of the field. 34274 34275 This second use of `length' also works on global variables, like: 34276 static GTY((length ("reg_base_value_size"))) 34277 rtx *reg_base_value; 34278 34279 `skip' 34280 If `skip' is applied to a field, the type machinery will ignore it. 34281 This is somewhat dangerous; the only safe use is in a union when 34282 one field really isn't ever used. 34283 34284 `desc ("EXPRESSION")' 34285 `tag ("CONSTANT")' 34286 `default' 34287 The type machinery needs to be told which field of a `union' is 34288 currently active. This is done by giving each field a constant 34289 `tag' value, and then specifying a discriminator using `desc'. 34290 The value of the expression given by `desc' is compared against 34291 each `tag' value, each of which should be different. If no `tag' 34292 is matched, the field marked with `default' is used if there is 34293 one, otherwise no field in the union will be marked. 34294 34295 In the `desc' option, the "current structure" is the union that it 34296 discriminates. Use `%1' to mean the structure containing it. 34297 There are no escapes available to the `tag' option, since it is a 34298 constant. 34299 34300 For example, 34301 struct tree_binding GTY(()) 34302 { 34303 struct tree_common common; 34304 union tree_binding_u { 34305 tree GTY ((tag ("0"))) scope; 34306 struct cp_binding_level * GTY ((tag ("1"))) level; 34307 } GTY ((desc ("BINDING_HAS_LEVEL_P ((tree)&%0)"))) xscope; 34308 tree value; 34309 }; 34310 34311 In this example, the value of BINDING_HAS_LEVEL_P when applied to a 34312 `struct tree_binding *' is presumed to be 0 or 1. If 1, the type 34313 mechanism will treat the field `level' as being present and if 0, 34314 will treat the field `scope' as being present. 34315 34316 `param_is (TYPE)' 34317 `use_param' 34318 Sometimes it's convenient to define some data structure to work on 34319 generic pointers (that is, `PTR') and then use it with a specific 34320 type. `param_is' specifies the real type pointed to, and 34321 `use_param' says where in the generic data structure that type 34322 should be put. 34323 34324 For instance, to have a `htab_t' that points to trees, one would 34325 write the definition of `htab_t' like this: 34326 typedef struct GTY(()) { 34327 ... 34328 void ** GTY ((use_param, ...)) entries; 34329 ... 34330 } htab_t; 34331 and then declare variables like this: 34332 static htab_t GTY ((param_is (union tree_node))) ict; 34333 34334 `paramN_is (TYPE)' 34335 `use_paramN' 34336 In more complicated cases, the data structure might need to work on 34337 several different types, which might not necessarily all be 34338 pointers. For this, `param1_is' through `param9_is' may be used to 34339 specify the real type of a field identified by `use_param1' through 34340 `use_param9'. 34341 34342 `use_params' 34343 When a structure contains another structure that is parameterized, 34344 there's no need to do anything special, the inner structure 34345 inherits the parameters of the outer one. When a structure 34346 contains a pointer to a parameterized structure, the type 34347 machinery won't automatically detect this (it could, it just 34348 doesn't yet), so it's necessary to tell it that the pointed-to 34349 structure should use the same parameters as the outer structure. 34350 This is done by marking the pointer with the `use_params' option. 34351 34352 `deletable' 34353 `deletable', when applied to a global variable, indicates that when 34354 garbage collection runs, there's no need to mark anything pointed 34355 to by this variable, it can just be set to `NULL' instead. This 34356 is used to keep a list of free structures around for re-use. 34357 34358 `if_marked ("EXPRESSION")' 34359 Suppose you want some kinds of object to be unique, and so you put 34360 them in a hash table. If garbage collection marks the hash table, 34361 these objects will never be freed, even if the last other 34362 reference to them goes away. GGC has special handling to deal 34363 with this: if you use the `if_marked' option on a global hash 34364 table, GGC will call the routine whose name is the parameter to 34365 the option on each hash table entry. If the routine returns 34366 nonzero, the hash table entry will be marked as usual. If the 34367 routine returns zero, the hash table entry will be deleted. 34368 34369 The routine `ggc_marked_p' can be used to determine if an element 34370 has been marked already; in fact, the usual case is to use 34371 `if_marked ("ggc_marked_p")'. 34372 34373 `mark_hook ("HOOK-ROUTINE-NAME")' 34374 If provided for a structure or union type, the given 34375 HOOK-ROUTINE-NAME (between double-quotes) is the name of a routine 34376 called when the garbage collector has just marked the data as 34377 reachable. This routine should not change the data, or call any ggc 34378 routine. Its only argument is a pointer to the just marked (const) 34379 structure or union. 34380 34381 `maybe_undef' 34382 When applied to a field, `maybe_undef' indicates that it's OK if 34383 the structure that this fields points to is never defined, so long 34384 as this field is always `NULL'. This is used to avoid requiring 34385 backends to define certain optional structures. It doesn't work 34386 with language frontends. 34387 34388 `nested_ptr (TYPE, "TO EXPRESSION", "FROM EXPRESSION")' 34389 The type machinery expects all pointers to point to the start of an 34390 object. Sometimes for abstraction purposes it's convenient to have 34391 a pointer which points inside an object. So long as it's possible 34392 to convert the original object to and from the pointer, such 34393 pointers can still be used. TYPE is the type of the original 34394 object, the TO EXPRESSION returns the pointer given the original 34395 object, and the FROM EXPRESSION returns the original object given 34396 the pointer. The pointer will be available using the `%h' escape. 34397 34398 `chain_next ("EXPRESSION")' 34399 `chain_prev ("EXPRESSION")' 34400 `chain_circular ("EXPRESSION")' 34401 It's helpful for the type machinery to know if objects are often 34402 chained together in long lists; this lets it generate code that 34403 uses less stack space by iterating along the list instead of 34404 recursing down it. `chain_next' is an expression for the next 34405 item in the list, `chain_prev' is an expression for the previous 34406 item. For singly linked lists, use only `chain_next'; for doubly 34407 linked lists, use both. The machinery requires that taking the 34408 next item of the previous item gives the original item. 34409 `chain_circular' is similar to `chain_next', but can be used for 34410 circular single linked lists. 34411 34412 `reorder ("FUNCTION NAME")' 34413 Some data structures depend on the relative ordering of pointers. 34414 If the precompiled header machinery needs to change that ordering, 34415 it will call the function referenced by the `reorder' option, 34416 before changing the pointers in the object that's pointed to by 34417 the field the option applies to. The function must take four 34418 arguments, with the signature 34419 `void *, void *, gt_pointer_operator, void *'. The first 34420 parameter is a pointer to the structure that contains the object 34421 being updated, or the object itself if there is no containing 34422 structure. The second parameter is a cookie that should be 34423 ignored. The third parameter is a routine that, given a pointer, 34424 will update it to its correct new value. The fourth parameter is 34425 a cookie that must be passed to the second parameter. 34426 34427 PCH cannot handle data structures that depend on the absolute 34428 values of pointers. `reorder' functions can be expensive. When 34429 possible, it is better to depend on properties of the data, like 34430 an ID number or the hash of a string instead. 34431 34432 `special ("NAME")' 34433 The `special' option is used to mark types that have to be dealt 34434 with by special case machinery. The parameter is the name of the 34435 special case. See `gengtype.c' for further details. Avoid adding 34436 new special cases unless there is no other alternative. 34437 34438 34439 File: gccint.info, Node: GGC Roots, Next: Files, Prev: GTY Options, Up: Type Information 34440 34441 22.2 Marking Roots for the Garbage Collector 34442 ============================================ 34443 34444 In addition to keeping track of types, the type machinery also locates 34445 the global variables ("roots") that the garbage collector starts at. 34446 Roots must be declared using one of the following syntaxes: 34447 34448 * `extern GTY(([OPTIONS])) TYPE NAME;' 34449 34450 * `static GTY(([OPTIONS])) TYPE NAME;' 34451 The syntax 34452 * `GTY(([OPTIONS])) TYPE NAME;' 34453 is _not_ accepted. There should be an `extern' declaration of such a 34454 variable in a header somewhere--mark that, not the definition. Or, if 34455 the variable is only used in one file, make it `static'. 34456 34457 34458 File: gccint.info, Node: Files, Next: Invoking the garbage collector, Prev: GGC Roots, Up: Type Information 34459 34460 22.3 Source Files Containing Type Information 34461 ============================================= 34462 34463 Whenever you add `GTY' markers to a source file that previously had 34464 none, or create a new source file containing `GTY' markers, there are 34465 three things you need to do: 34466 34467 1. You need to add the file to the list of source files the type 34468 machinery scans. There are four cases: 34469 34470 a. For a back-end file, this is usually done automatically; if 34471 not, you should add it to `target_gtfiles' in the appropriate 34472 port's entries in `config.gcc'. 34473 34474 b. For files shared by all front ends, add the filename to the 34475 `GTFILES' variable in `Makefile.in'. 34476 34477 c. For files that are part of one front end, add the filename to 34478 the `gtfiles' variable defined in the appropriate 34479 `config-lang.in'. For C, the file is `c-config-lang.in'. 34480 Headers should appear before non-headers in this list. 34481 34482 d. For files that are part of some but not all front ends, add 34483 the filename to the `gtfiles' variable of _all_ the front ends 34484 that use it. 34485 34486 2. If the file was a header file, you'll need to check that it's 34487 included in the right place to be visible to the generated files. 34488 For a back-end header file, this should be done automatically. 34489 For a front-end header file, it needs to be included by the same 34490 file that includes `gtype-LANG.h'. For other header files, it 34491 needs to be included in `gtype-desc.c', which is a generated file, 34492 so add it to `ifiles' in `open_base_file' in `gengtype.c'. 34493 34494 For source files that aren't header files, the machinery will 34495 generate a header file that should be included in the source file 34496 you just changed. The file will be called `gt-PATH.h' where PATH 34497 is the pathname relative to the `gcc' directory with slashes 34498 replaced by -, so for example the header file to be included in 34499 `cp/parser.c' is called `gt-cp-parser.c'. The generated header 34500 file should be included after everything else in the source file. 34501 Don't forget to mention this file as a dependency in the 34502 `Makefile'! 34503 34504 34505 For language frontends, there is another file that needs to be included 34506 somewhere. It will be called `gtype-LANG.h', where LANG is the name of 34507 the subdirectory the language is contained in. 34508 34509 Plugins can add additional root tables. Run the `gengtype' utility in 34510 plugin mode as `gengtype -p SOURCE-DIR FILE-LIST PLUGIN*.C' with your 34511 plugin files PLUGIN*.C using `GTY' to generate the corresponding 34512 GT-PLUGIN*.H files. The GCC build tree is needed to be present in that 34513 mode. 34514 34515 34516 File: gccint.info, Node: Invoking the garbage collector, Prev: Files, Up: Type Information 34517 34518 22.4 How to invoke the garbage collector 34519 ======================================== 34520 34521 The GCC garbage collector GGC is only invoked explicitly. In contrast 34522 with many other garbage collectors, it is not implicitly invoked by 34523 allocation routines when a lot of memory has been consumed. So the only 34524 way to have GGC reclaim storage it to call the `ggc_collect' function 34525 explicitly. This call is an expensive operation, as it may have to scan 34526 the entire heap. Beware that local variables (on the GCC call stack) 34527 are not followed by such an invocation (as many other garbage 34528 collectors do): you should reference all your data from static or 34529 external `GTY'-ed variables, and it is advised to call `ggc_collect' 34530 with a shallow call stack. The GGC is an exact mark and sweep garbage 34531 collector (so it does not scan the call stack for pointers). In 34532 practice GCC passes don't often call `ggc_collect' themselves, because 34533 it is called by the pass manager between passes. 34534 34535 34536 File: gccint.info, Node: Plugins, Next: Funding, Prev: Type Information, Up: Top 34537 34538 23 Plugins 34539 ********** 34540 34541 23.1 Loading Plugins 34542 ==================== 34543 34544 Plugins are supported on platforms that support `-ldl -rdynamic'. They 34545 are loaded by the compiler using `dlopen' and invoked at pre-determined 34546 locations in the compilation process. 34547 34548 Plugins are loaded with 34549 34550 `-fplugin=/path/to/NAME.so' `-fplugin-arg-NAME-<key1>[=<value1>]' 34551 34552 The plugin arguments are parsed by GCC and passed to respective 34553 plugins as key-value pairs. Multiple plugins can be invoked by 34554 specifying multiple `-fplugin' arguments. 34555 34556 23.2 Plugin API 34557 =============== 34558 34559 Plugins are activated by the compiler at specific events as defined in 34560 `gcc-plugin.h'. For each event of interest, the plugin should call 34561 `register_callback' specifying the name of the event and address of the 34562 callback function that will handle that event. 34563 34564 The header `gcc-plugin.h' must be the first gcc header to be included. 34565 34566 23.2.1 Plugin initialization 34567 ---------------------------- 34568 34569 Every plugin should export a function called `plugin_init' that is 34570 called right after the plugin is loaded. This function is responsible 34571 for registering all the callbacks required by the plugin and do any 34572 other required initialization. 34573 34574 This function is called from `compile_file' right before invoking the 34575 parser. The arguments to `plugin_init' are: 34576 34577 * `plugin_info': Plugin invocation information. 34578 34579 * `version': GCC version. 34580 34581 The `plugin_info' struct is defined as follows: 34582 34583 struct plugin_name_args 34584 { 34585 char *base_name; /* Short name of the plugin 34586 (filename without .so suffix). */ 34587 const char *full_name; /* Path to the plugin as specified with 34588 -fplugin=. */ 34589 int argc; /* Number of arguments specified with 34590 -fplugin-arg-.... */ 34591 struct plugin_argument *argv; /* Array of ARGC key-value pairs. */ 34592 const char *version; /* Version string provided by plugin. */ 34593 const char *help; /* Help string provided by plugin. */ 34594 } 34595 34596 If initialization fails, `plugin_init' must return a non-zero value. 34597 Otherwise, it should return 0. 34598 34599 The version of the GCC compiler loading the plugin is described by the 34600 following structure: 34601 34602 struct plugin_gcc_version 34603 { 34604 const char *basever; 34605 const char *datestamp; 34606 const char *devphase; 34607 const char *revision; 34608 const char *configuration_arguments; 34609 }; 34610 34611 The function `plugin_default_version_check' takes two pointers to such 34612 structure and compare them field by field. It can be used by the 34613 plugin's `plugin_init' function. 34614 34615 23.2.2 Plugin callbacks 34616 ----------------------- 34617 34618 Callback functions have the following prototype: 34619 34620 /* The prototype for a plugin callback function. 34621 gcc_data - event-specific data provided by GCC 34622 user_data - plugin-specific data provided by the plug-in. */ 34623 typedef void (*plugin_callback_func)(void *gcc_data, void *user_data); 34624 34625 Callbacks can be invoked at the following pre-determined events: 34626 34627 enum plugin_event 34628 { 34629 PLUGIN_PASS_MANAGER_SETUP, /* To hook into pass manager. */ 34630 PLUGIN_FINISH_TYPE, /* After finishing parsing a type. */ 34631 PLUGIN_FINISH_UNIT, /* Useful for summary processing. */ 34632 PLUGIN_CXX_CP_PRE_GENERICIZE, /* Allows to see low level AST in C++ FE. */ 34633 PLUGIN_FINISH, /* Called before GCC exits. */ 34634 PLUGIN_INFO, /* Information about the plugin. */ 34635 PLUGIN_GGC_START, /* Called at start of GCC Garbage Collection. */ 34636 PLUGIN_GGC_MARKING, /* Extend the GGC marking. */ 34637 PLUGIN_GGC_END, /* Called at end of GGC. */ 34638 PLUGIN_REGISTER_GGC_ROOTS, /* Register an extra GGC root table. */ 34639 PLUGIN_ATTRIBUTES, /* Called during attribute registration */ 34640 PLUGIN_START_UNIT, /* Called before processing a translation unit. */ 34641 PLUGIN_EVENT_LAST /* Dummy event used for indexing callback 34642 array. */ 34643 }; 34644 34645 To register a callback, the plugin calls `register_callback' with the 34646 arguments: 34647 34648 * `char *name': Plugin name. 34649 34650 * `enum plugin_event event': The event code. 34651 34652 * `plugin_callback_func callback': The function that handles `event'. 34653 34654 * `void *user_data': Pointer to plugin-specific data. 34655 34656 For the PLUGIN_PASS_MANAGER_SETUP, PLUGIN_INFO, and 34657 PLUGIN_REGISTER_GGC_ROOTS pseudo-events the `callback' should be null, 34658 and the `user_data' is specific. 34659 34660 23.3 Interacting with the pass manager 34661 ====================================== 34662 34663 There needs to be a way to add/reorder/remove passes dynamically. This 34664 is useful for both analysis plugins (plugging in after a certain pass 34665 such as CFG or an IPA pass) and optimization plugins. 34666 34667 Basic support for inserting new passes or replacing existing passes is 34668 provided. A plugin registers a new pass with GCC by calling 34669 `register_callback' with the `PLUGIN_PASS_MANAGER_SETUP' event and a 34670 pointer to a `struct plugin_pass' object defined as follows 34671 34672 enum pass_positioning_ops 34673 { 34674 PASS_POS_INSERT_AFTER, // Insert after the reference pass. 34675 PASS_POS_INSERT_BEFORE, // Insert before the reference pass. 34676 PASS_POS_REPLACE // Replace the reference pass. 34677 }; 34678 34679 struct plugin_pass 34680 { 34681 struct opt_pass *pass; /* New pass provided by the plugin. */ 34682 const char *reference_pass_name; /* Name of the reference pass for hooking 34683 up the new pass. */ 34684 int ref_pass_instance_number; /* Insert the pass at the specified 34685 instance number of the reference pass. */ 34686 /* Do it for every instance if it is 0. */ 34687 enum pass_positioning_ops pos_op; /* how to insert the new pass. */ 34688 }; 34689 34690 34691 /* Sample plugin code that registers a new pass. */ 34692 int 34693 plugin_init (struct plugin_name_args *plugin_info, 34694 struct plugin_gcc_version *version) 34695 { 34696 struct plugin_pass pass_info; 34697 34698 ... 34699 34700 /* Code to fill in the pass_info object with new pass information. */ 34701 34702 ... 34703 34704 /* Register the new pass. */ 34705 register_callback (plugin_info->base_name, PLUGIN_PASS_MANAGER_SETUP, NULL, &pass_info); 34706 34707 ... 34708 } 34709 34710 23.4 Interacting with the GCC Garbage Collector 34711 =============================================== 34712 34713 Some plugins may want to be informed when GGC (the GCC Garbage 34714 Collector) is running. They can register callbacks for the 34715 `PLUGIN_GGC_START' and `PLUGIN_GGC_END' events (for which the callback 34716 is called with a null `gcc_data') to be notified of the start or end of 34717 the GCC garbage collection. 34718 34719 Some plugins may need to have GGC mark additional data. This can be 34720 done by registering a callback (called with a null `gcc_data') for the 34721 `PLUGIN_GGC_MARKING' event. Such callbacks can call the `ggc_set_mark' 34722 routine, preferably thru the `ggc_mark' macro (and conversely, these 34723 routines should usually not be used in plugins outside of the 34724 `PLUGIN_GGC_MARKING' event). 34725 34726 Some plugins may need to add extra GGC root tables, e.g. to handle 34727 their own `GTY'-ed data. This can be done with the 34728 `PLUGIN_REGISTER_GGC_ROOTS' pseudo-event with a null callback and the 34729 extra root table as `user_data'. Running the `gengtype -p SOURCE-DIR 34730 FILE-LIST PLUGIN*.C ...' utility generates this extra root table. 34731 34732 You should understand the details of memory management inside GCC 34733 before using `PLUGIN_GGC_MARKING' or `PLUGIN_REGISTER_GGC_ROOTS'. 34734 34735 23.5 Giving information about a plugin 34736 ====================================== 34737 34738 A plugin should give some information to the user about itself. This 34739 uses the following structure: 34740 34741 struct plugin_info 34742 { 34743 const char *version; 34744 const char *help; 34745 }; 34746 34747 Such a structure is passed as the `user_data' by the plugin's init 34748 routine using `register_callback' with the `PLUGIN_INFO' pseudo-event 34749 and a null callback. 34750 34751 23.6 Registering custom attributes 34752 ================================== 34753 34754 For analysis purposes it is useful to be able to add custom attributes. 34755 34756 The `PLUGIN_ATTRIBUTES' callback is called during attribute 34757 registration. Use the `register_attribute' function to register custom 34758 attributes. 34759 34760 /* Attribute handler callback */ 34761 static tree 34762 handle_user_attribute (tree *node, tree name, tree args, 34763 int flags, bool *no_add_attrs) 34764 { 34765 return NULL_TREE; 34766 } 34767 34768 /* Attribute definition */ 34769 static struct attribute_spec user_attr = 34770 { "user", 1, 1, false, false, false, handle_user_attribute }; 34771 34772 /* Plugin callback called during attribute registration. 34773 Registered with register_callback (plugin_name, PLUGIN_ATTRIBUTES, register_attributes, NULL) 34774 */ 34775 static void 34776 register_attributes (void *event_data, void *data) 34777 { 34778 warning (0, G_("Callback to register attributes")); 34779 register_attribute (&user_attr); 34780 } 34781 34782 23.7 Building GCC plugins 34783 ========================= 34784 34785 If plugins are enabled, GCC installs the headers needed to build a 34786 plugin (somehwere in the installation tree, e.g. under `/usr/local'). 34787 In particular a `plugin/include' directory is installed, containing all 34788 the header files needed to build plugins. 34789 34790 On most systems, you can query this `plugin' directory by invoking 34791 `gcc -print-file-name=plugin' (replace if needed `gcc' with the 34792 appropriate program path). 34793 34794 The following GNU Makefile excerpt shows how to build a simple plugin: 34795 34796 GCC=gcc 34797 PLUGIN_SOURCE_FILES= plugin1.c plugin2.c 34798 PLUGIN_OBJECT_FILES= $(patsubst %.c,%.o,$(PLUGIN_SOURCE_FILES)) 34799 GCCPLUGINS_DIR:= $(shell $(GCC) -print-file-name=plugin) 34800 CFLAGS+= -I$(GCCPLUGINS_DIR)/include -fPIC -O2 34801 34802 plugin.so: $(PLUGIN_OBJECT_FILES) 34803 $(GCC) -shared $^ -o $ 34804 34805 A single source file plugin may be built with `gcc -I`gcc 34806 -print-file-name=plugin`/include -fPIC -shared -O2 plugin.c -o 34807 plugin.so', using backquote shell syntax to query the `plugin' 34808 directory. 34809 34810 Plugins needing to use `gengtype' require a GCC build directory for 34811 the same version of GCC that they will be linked against. 34812 34813 34814 File: gccint.info, Node: Funding, Next: GNU Project, Prev: Plugins, Up: Top 34815 34816 Funding Free Software 34817 ********************* 34818 34819 If you want to have more free software a few years from now, it makes 34820 sense for you to help encourage people to contribute funds for its 34821 development. The most effective approach known is to encourage 34822 commercial redistributors to donate. 34823 34824 Users of free software systems can boost the pace of development by 34825 encouraging for-a-fee distributors to donate part of their selling price 34826 to free software developers--the Free Software Foundation, and others. 34827 34828 The way to convince distributors to do this is to demand it and expect 34829 it from them. So when you compare distributors, judge them partly by 34830 how much they give to free software development. Show distributors 34831 they must compete to be the one who gives the most. 34832 34833 To make this approach work, you must insist on numbers that you can 34834 compare, such as, "We will donate ten dollars to the Frobnitz project 34835 for each disk sold." Don't be satisfied with a vague promise, such as 34836 "A portion of the profits are donated," since it doesn't give a basis 34837 for comparison. 34838 34839 Even a precise fraction "of the profits from this disk" is not very 34840 meaningful, since creative accounting and unrelated business decisions 34841 can greatly alter what fraction of the sales price counts as profit. 34842 If the price you pay is $50, ten percent of the profit is probably less 34843 than a dollar; it might be a few cents, or nothing at all. 34844 34845 Some redistributors do development work themselves. This is useful 34846 too; but to keep everyone honest, you need to inquire how much they do, 34847 and what kind. Some kinds of development make much more long-term 34848 difference than others. For example, maintaining a separate version of 34849 a program contributes very little; maintaining the standard version of a 34850 program for the whole community contributes much. Easy new ports 34851 contribute little, since someone else would surely do them; difficult 34852 ports such as adding a new CPU to the GNU Compiler Collection 34853 contribute more; major new features or packages contribute the most. 34854 34855 By establishing the idea that supporting further development is "the 34856 proper thing to do" when distributing free software for a fee, we can 34857 assure a steady flow of resources into making more free software. 34858 34859 Copyright (C) 1994 Free Software Foundation, Inc. 34860 Verbatim copying and redistribution of this section is permitted 34861 without royalty; alteration is not permitted. 34862 34863 34864 File: gccint.info, Node: GNU Project, Next: Copying, Prev: Funding, Up: Top 34865 34866 The GNU Project and GNU/Linux 34867 ***************************** 34868 34869 The GNU Project was launched in 1984 to develop a complete Unix-like 34870 operating system which is free software: the GNU system. (GNU is a 34871 recursive acronym for "GNU's Not Unix"; it is pronounced "guh-NEW".) 34872 Variants of the GNU operating system, which use the kernel Linux, are 34873 now widely used; though these systems are often referred to as "Linux", 34874 they are more accurately called GNU/Linux systems. 34875 34876 For more information, see: 34877 `http://www.gnu.org/' 34878 `http://www.gnu.org/gnu/linux-and-gnu.html' 34879 34880 34881 File: gccint.info, Node: Copying, Next: GNU Free Documentation License, Prev: GNU Project, Up: Top 34882 34883 GNU General Public License 34884 ************************** 34885 34886 Version 3, 29 June 2007 34887 34888 Copyright (C) 2007 Free Software Foundation, Inc. `http://fsf.org/' 34889 34890 Everyone is permitted to copy and distribute verbatim copies of this 34891 license document, but changing it is not allowed. 34892 34893 Preamble 34894 ======== 34895 34896 The GNU General Public License is a free, copyleft license for software 34897 and other kinds of works. 34898 34899 The licenses for most software and other practical works are designed 34900 to take away your freedom to share and change the works. By contrast, 34901 the GNU General Public License is intended to guarantee your freedom to 34902 share and change all versions of a program-to make sure it remains free 34903 software for all its users. We, the Free Software Foundation, use the 34904 GNU General Public License for most of our software; it applies also to 34905 any other work released this way by its authors. You can apply it to 34906 your programs, too. 34907 34908 When we speak of free software, we are referring to freedom, not 34909 price. Our General Public Licenses are designed to make sure that you 34910 have the freedom to distribute copies of free software (and charge for 34911 them if you wish), that you receive source code or can get it if you 34912 want it, that you can change the software or use pieces of it in new 34913 free programs, and that you know you can do these things. 34914 34915 To protect your rights, we need to prevent others from denying you 34916 these rights or asking you to surrender the rights. Therefore, you 34917 have certain responsibilities if you distribute copies of the software, 34918 or if you modify it: responsibilities to respect the freedom of others. 34919 34920 For example, if you distribute copies of such a program, whether 34921 gratis or for a fee, you must pass on to the recipients the same 34922 freedoms that you received. You must make sure that they, too, receive 34923 or can get the source code. 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Access to a network may be denied 35237 when the modification itself materially and adversely affects the 35238 operation of the network or violates the rules and protocols for 35239 communication across the network. 35240 35241 Corresponding Source conveyed, and Installation Information 35242 provided, in accord with this section must be in a format that is 35243 publicly documented (and with an implementation available to the 35244 public in source code form), and must require no special password 35245 or key for unpacking, reading or copying. 35246 35247 7. Additional Terms. 35248 35249 "Additional permissions" are terms that supplement the terms of 35250 this License by making exceptions from one or more of its 35251 conditions. Additional permissions that are applicable to the 35252 entire Program shall be treated as though they were included in 35253 this License, to the extent that they are valid under applicable 35254 law. If additional permissions apply only to part of the Program, 35255 that part may be used separately under those permissions, but the 35256 entire Program remains governed by this License without regard to 35257 the additional permissions. 35258 35259 When you convey a copy of a covered work, you may at your option 35260 remove any additional permissions from that copy, or from any part 35261 of it. (Additional permissions may be written to require their own 35262 removal in certain cases when you modify the work.) You may place 35263 additional permissions on material, added by you to a covered work, 35264 for which you have or can give appropriate copyright permission. 35265 35266 Notwithstanding any other provision of this License, for material 35267 you add to a covered work, you may (if authorized by the copyright 35268 holders of that material) supplement the terms of this License 35269 with terms: 35270 35271 a. Disclaiming warranty or limiting liability differently from 35272 the terms of sections 15 and 16 of this License; or 35273 35274 b. Requiring preservation of specified reasonable legal notices 35275 or author attributions in that material or in the Appropriate 35276 Legal Notices displayed by works containing it; or 35277 35278 c. Prohibiting misrepresentation of the origin of that material, 35279 or requiring that modified versions of such material be 35280 marked in reasonable ways as different from the original 35281 version; or 35282 35283 d. Limiting the use for publicity purposes of names of licensors 35284 or authors of the material; or 35285 35286 e. Declining to grant rights under trademark law for use of some 35287 trade names, trademarks, or service marks; or 35288 35289 f. Requiring indemnification of licensors and authors of that 35290 material by anyone who conveys the material (or modified 35291 versions of it) with contractual assumptions of liability to 35292 the recipient, for any liability that these contractual 35293 assumptions directly impose on those licensors and authors. 35294 35295 All other non-permissive additional terms are considered "further 35296 restrictions" within the meaning of section 10. If the Program as 35297 you received it, or any part of it, contains a notice stating that 35298 it is governed by this License along with a term that is a further 35299 restriction, you may remove that term. If a license document 35300 contains a further restriction but permits relicensing or 35301 conveying under this License, you may add to a covered work 35302 material governed by the terms of that license document, provided 35303 that the further restriction does not survive such relicensing or 35304 conveying. 35305 35306 If you add terms to a covered work in accord with this section, you 35307 must place, in the relevant source files, a statement of the 35308 additional terms that apply to those files, or a notice indicating 35309 where to find the applicable terms. 35310 35311 Additional terms, permissive or non-permissive, may be stated in 35312 the form of a separately written license, or stated as exceptions; 35313 the above requirements apply either way. 35314 35315 8. Termination. 35316 35317 You may not propagate or modify a covered work except as expressly 35318 provided under this License. Any attempt otherwise to propagate or 35319 modify it is void, and will automatically terminate your rights 35320 under this License (including any patent licenses granted under 35321 the third paragraph of section 11). 35322 35323 However, if you cease all violation of this License, then your 35324 license from a particular copyright holder is reinstated (a) 35325 provisionally, unless and until the copyright holder explicitly 35326 and finally terminates your license, and (b) permanently, if the 35327 copyright holder fails to notify you of the violation by some 35328 reasonable means prior to 60 days after the cessation. 35329 35330 Moreover, your license from a particular copyright holder is 35331 reinstated permanently if the copyright holder notifies you of the 35332 violation by some reasonable means, this is the first time you have 35333 received notice of violation of this License (for any work) from 35334 that copyright holder, and you cure the violation prior to 30 days 35335 after your receipt of the notice. 35336 35337 Termination of your rights under this section does not terminate 35338 the licenses of parties who have received copies or rights from 35339 you under this License. If your rights have been terminated and 35340 not permanently reinstated, you do not qualify to receive new 35341 licenses for the same material under section 10. 35342 35343 9. Acceptance Not Required for Having Copies. 35344 35345 You are not required to accept this License in order to receive or 35346 run a copy of the Program. Ancillary propagation of a covered work 35347 occurring solely as a consequence of using peer-to-peer 35348 transmission to receive a copy likewise does not require 35349 acceptance. However, nothing other than this License grants you 35350 permission to propagate or modify any covered work. These actions 35351 infringe copyright if you do not accept this License. Therefore, 35352 by modifying or propagating a covered work, you indicate your 35353 acceptance of this License to do so. 35354 35355 10. Automatic Licensing of Downstream Recipients. 35356 35357 Each time you convey a covered work, the recipient automatically 35358 receives a license from the original licensors, to run, modify and 35359 propagate that work, subject to this License. You are not 35360 responsible for enforcing compliance by third parties with this 35361 License. 35362 35363 An "entity transaction" is a transaction transferring control of an 35364 organization, or substantially all assets of one, or subdividing an 35365 organization, or merging organizations. If propagation of a 35366 covered work results from an entity transaction, each party to that 35367 transaction who receives a copy of the work also receives whatever 35368 licenses to the work the party's predecessor in interest had or 35369 could give under the previous paragraph, plus a right to 35370 possession of the Corresponding Source of the work from the 35371 predecessor in interest, if the predecessor has it or can get it 35372 with reasonable efforts. 35373 35374 You may not impose any further restrictions on the exercise of the 35375 rights granted or affirmed under this License. For example, you 35376 may not impose a license fee, royalty, or other charge for 35377 exercise of rights granted under this License, and you may not 35378 initiate litigation (including a cross-claim or counterclaim in a 35379 lawsuit) alleging that any patent claim is infringed by making, 35380 using, selling, offering for sale, or importing the Program or any 35381 portion of it. 35382 35383 11. Patents. 35384 35385 A "contributor" is a copyright holder who authorizes use under this 35386 License of the Program or a work on which the Program is based. 35387 The work thus licensed is called the contributor's "contributor 35388 version". 35389 35390 A contributor's "essential patent claims" are all patent claims 35391 owned or controlled by the contributor, whether already acquired or 35392 hereafter acquired, that would be infringed by some manner, 35393 permitted by this License, of making, using, or selling its 35394 contributor version, but do not include claims that would be 35395 infringed only as a consequence of further modification of the 35396 contributor version. For purposes of this definition, "control" 35397 includes the right to grant patent sublicenses in a manner 35398 consistent with the requirements of this License. 35399 35400 Each contributor grants you a non-exclusive, worldwide, 35401 royalty-free patent license under the contributor's essential 35402 patent claims, to make, use, sell, offer for sale, import and 35403 otherwise run, modify and propagate the contents of its 35404 contributor version. 35405 35406 In the following three paragraphs, a "patent license" is any 35407 express agreement or commitment, however denominated, not to 35408 enforce a patent (such as an express permission to practice a 35409 patent or covenant not to sue for patent infringement). To 35410 "grant" such a patent license to a party means to make such an 35411 agreement or commitment not to enforce a patent against the party. 35412 35413 If you convey a covered work, knowingly relying on a patent 35414 license, and the Corresponding Source of the work is not available 35415 for anyone to copy, free of charge and under the terms of this 35416 License, through a publicly available network server or other 35417 readily accessible means, then you must either (1) cause the 35418 Corresponding Source to be so available, or (2) arrange to deprive 35419 yourself of the benefit of the patent license for this particular 35420 work, or (3) arrange, in a manner consistent with the requirements 35421 of this License, to extend the patent license to downstream 35422 recipients. "Knowingly relying" means you have actual knowledge 35423 that, but for the patent license, your conveying the covered work 35424 in a country, or your recipient's use of the covered work in a 35425 country, would infringe one or more identifiable patents in that 35426 country that you have reason to believe are valid. 35427 35428 If, pursuant to or in connection with a single transaction or 35429 arrangement, you convey, or propagate by procuring conveyance of, a 35430 covered work, and grant a patent license to some of the parties 35431 receiving the covered work authorizing them to use, propagate, 35432 modify or convey a specific copy of the covered work, then the 35433 patent license you grant is automatically extended to all 35434 recipients of the covered work and works based on it. 35435 35436 A patent license is "discriminatory" if it does not include within 35437 the scope of its coverage, prohibits the exercise of, or is 35438 conditioned on the non-exercise of one or more of the rights that 35439 are specifically granted under this License. You may not convey a 35440 covered work if you are a party to an arrangement with a third 35441 party that is in the business of distributing software, under 35442 which you make payment to the third party based on the extent of 35443 your activity of conveying the work, and under which the third 35444 party grants, to any of the parties who would receive the covered 35445 work from you, a discriminatory patent license (a) in connection 35446 with copies of the covered work conveyed by you (or copies made 35447 from those copies), or (b) primarily for and in connection with 35448 specific products or compilations that contain the covered work, 35449 unless you entered into that arrangement, or that patent license 35450 was granted, prior to 28 March 2007. 35451 35452 Nothing in this License shall be construed as excluding or limiting 35453 any implied license or other defenses to infringement that may 35454 otherwise be available to you under applicable patent law. 35455 35456 12. No Surrender of Others' Freedom. 35457 35458 If conditions are imposed on you (whether by court order, 35459 agreement or otherwise) that contradict the conditions of this 35460 License, they do not excuse you from the conditions of this 35461 License. If you cannot convey a covered work so as to satisfy 35462 simultaneously your obligations under this License and any other 35463 pertinent obligations, then as a consequence you may not convey it 35464 at all. For example, if you agree to terms that obligate you to 35465 collect a royalty for further conveying from those to whom you 35466 convey the Program, the only way you could satisfy both those 35467 terms and this License would be to refrain entirely from conveying 35468 the Program. 35469 35470 13. Use with the GNU Affero General Public License. 35471 35472 Notwithstanding any other provision of this License, you have 35473 permission to link or combine any covered work with a work licensed 35474 under version 3 of the GNU Affero General Public License into a 35475 single combined work, and to convey the resulting work. The terms 35476 of this License will continue to apply to the part which is the 35477 covered work, but the special requirements of the GNU Affero 35478 General Public License, section 13, concerning interaction through 35479 a network will apply to the combination as such. 35480 35481 14. Revised Versions of this License. 35482 35483 The Free Software Foundation may publish revised and/or new 35484 versions of the GNU General Public License from time to time. 35485 Such new versions will be similar in spirit to the present 35486 version, but may differ in detail to address new problems or 35487 concerns. 35488 35489 Each version is given a distinguishing version number. If the 35490 Program specifies that a certain numbered version of the GNU 35491 General Public License "or any later version" applies to it, you 35492 have the option of following the terms and conditions either of 35493 that numbered version or of any later version published by the 35494 Free Software Foundation. If the Program does not specify a 35495 version number of the GNU General Public License, you may choose 35496 any version ever published by the Free Software Foundation. 35497 35498 If the Program specifies that a proxy can decide which future 35499 versions of the GNU General Public License can be used, that 35500 proxy's public statement of acceptance of a version permanently 35501 authorizes you to choose that version for the Program. 35502 35503 Later license versions may give you additional or different 35504 permissions. However, no additional obligations are imposed on any 35505 author or copyright holder as a result of your choosing to follow a 35506 later version. 35507 35508 15. Disclaimer of Warranty. 35509 35510 THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY 35511 APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE 35512 COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" 35513 WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, 35514 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 35515 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE 35516 RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. 35517 SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL 35518 NECESSARY SERVICING, REPAIR OR CORRECTION. 35519 35520 16. Limitation of Liability. 35521 35522 IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN 35523 WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES 35524 AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU 35525 FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR 35526 CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE 35527 THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA 35528 BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD 35529 PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER 35530 PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF 35531 THE POSSIBILITY OF SUCH DAMAGES. 35532 35533 17. Interpretation of Sections 15 and 16. 35534 35535 If the disclaimer of warranty and limitation of liability provided 35536 above cannot be given local legal effect according to their terms, 35537 reviewing courts shall apply local law that most closely 35538 approximates an absolute waiver of all civil liability in 35539 connection with the Program, unless a warranty or assumption of 35540 liability accompanies a copy of the Program in return for a fee. 35541 35542 35543 END OF TERMS AND CONDITIONS 35544 =========================== 35545 35546 How to Apply These Terms to Your New Programs 35547 ============================================= 35548 35549 If you develop a new program, and you want it to be of the greatest 35550 possible use to the public, the best way to achieve this is to make it 35551 free software which everyone can redistribute and change under these 35552 terms. 35553 35554 To do so, attach the following notices to the program. It is safest 35555 to attach them to the start of each source file to most effectively 35556 state the exclusion of warranty; and each file should have at least the 35557 "copyright" line and a pointer to where the full notice is found. 35558 35559 ONE LINE TO GIVE THE PROGRAM'S NAME AND A BRIEF IDEA OF WHAT IT DOES. 35560 Copyright (C) YEAR NAME OF AUTHOR 35561 35562 This program is free software: you can redistribute it and/or modify 35563 it under the terms of the GNU General Public License as published by 35564 the Free Software Foundation, either version 3 of the License, or (at 35565 your option) any later version. 35566 35567 This program is distributed in the hope that it will be useful, but 35568 WITHOUT ANY WARRANTY; without even the implied warranty of 35569 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 35570 General Public License for more details. 35571 35572 You should have received a copy of the GNU General Public License 35573 along with this program. If not, see `http://www.gnu.org/licenses/'. 35574 35575 Also add information on how to contact you by electronic and paper 35576 mail. 35577 35578 If the program does terminal interaction, make it output a short 35579 notice like this when it starts in an interactive mode: 35580 35581 PROGRAM Copyright (C) YEAR NAME OF AUTHOR 35582 This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 35583 This is free software, and you are welcome to redistribute it 35584 under certain conditions; type `show c' for details. 35585 35586 The hypothetical commands `show w' and `show c' should show the 35587 appropriate parts of the General Public License. Of course, your 35588 program's commands might be different; for a GUI interface, you would 35589 use an "about box". 35590 35591 You should also get your employer (if you work as a programmer) or 35592 school, if any, to sign a "copyright disclaimer" for the program, if 35593 necessary. For more information on this, and how to apply and follow 35594 the GNU GPL, see `http://www.gnu.org/licenses/'. 35595 35596 The GNU General Public License does not permit incorporating your 35597 program into proprietary programs. If your program is a subroutine 35598 library, you may consider it more useful to permit linking proprietary 35599 applications with the library. If this is what you want to do, use the 35600 GNU Lesser General Public License instead of this License. But first, 35601 please read `http://www.gnu.org/philosophy/why-not-lgpl.html'. 35602 35603 35604 File: gccint.info, Node: GNU Free Documentation License, Next: Contributors, Prev: Copying, Up: Top 35605 35606 GNU Free Documentation License 35607 ****************************** 35608 35609 Version 1.2, November 2002 35610 35611 Copyright (C) 2000,2001,2002 Free Software Foundation, Inc. 35612 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA 35613 35614 Everyone is permitted to copy and distribute verbatim copies 35615 of this license document, but changing it is not allowed. 35616 35617 0. PREAMBLE 35618 35619 The purpose of this License is to make a manual, textbook, or other 35620 functional and useful document "free" in the sense of freedom: to 35621 assure everyone the effective freedom to copy and redistribute it, 35622 with or without modifying it, either commercially or 35623 noncommercially. Secondarily, this License preserves for the 35624 author and publisher a way to get credit for their work, while not 35625 being considered responsible for modifications made by others. 35626 35627 This License is a kind of "copyleft", which means that derivative 35628 works of the document must themselves be free in the same sense. 35629 It complements the GNU General Public License, which is a copyleft 35630 license designed for free software. 35631 35632 We have designed this License in order to use it for manuals for 35633 free software, because free software needs free documentation: a 35634 free program should come with manuals providing the same freedoms 35635 that the software does. But this License is not limited to 35636 software manuals; it can be used for any textual work, regardless 35637 of subject matter or whether it is published as a printed book. 35638 We recommend this License principally for works whose purpose is 35639 instruction or reference. 35640 35641 1. APPLICABILITY AND DEFINITIONS 35642 35643 This License applies to any manual or other work, in any medium, 35644 that contains a notice placed by the copyright holder saying it 35645 can be distributed under the terms of this License. Such a notice 35646 grants a world-wide, royalty-free license, unlimited in duration, 35647 to use that work under the conditions stated herein. The 35648 "Document", below, refers to any such manual or work. Any member 35649 of the public is a licensee, and is addressed as "you". You 35650 accept the license if you copy, modify or distribute the work in a 35651 way requiring permission under copyright law. 35652 35653 A "Modified Version" of the Document means any work containing the 35654 Document or a portion of it, either copied verbatim, or with 35655 modifications and/or translated into another language. 35656 35657 A "Secondary Section" is a named appendix or a front-matter section 35658 of the Document that deals exclusively with the relationship of the 35659 publishers or authors of the Document to the Document's overall 35660 subject (or to related matters) and contains nothing that could 35661 fall directly within that overall subject. (Thus, if the Document 35662 is in part a textbook of mathematics, a Secondary Section may not 35663 explain any mathematics.) The relationship could be a matter of 35664 historical connection with the subject or with related matters, or 35665 of legal, commercial, philosophical, ethical or political position 35666 regarding them. 35667 35668 The "Invariant Sections" are certain Secondary Sections whose 35669 titles are designated, as being those of Invariant Sections, in 35670 the notice that says that the Document is released under this 35671 License. If a section does not fit the above definition of 35672 Secondary then it is not allowed to be designated as Invariant. 35673 The Document may contain zero Invariant Sections. If the Document 35674 does not identify any Invariant Sections then there are none. 35675 35676 The "Cover Texts" are certain short passages of text that are 35677 listed, as Front-Cover Texts or Back-Cover Texts, in the notice 35678 that says that the Document is released under this License. A 35679 Front-Cover Text may be at most 5 words, and a Back-Cover Text may 35680 be at most 25 words. 35681 35682 A "Transparent" copy of the Document means a machine-readable copy, 35683 represented in a format whose specification is available to the 35684 general public, that is suitable for revising the document 35685 straightforwardly with generic text editors or (for images 35686 composed of pixels) generic paint programs or (for drawings) some 35687 widely available drawing editor, and that is suitable for input to 35688 text formatters or for automatic translation to a variety of 35689 formats suitable for input to text formatters. A copy made in an 35690 otherwise Transparent file format whose markup, or absence of 35691 markup, has been arranged to thwart or discourage subsequent 35692 modification by readers is not Transparent. An image format is 35693 not Transparent if used for any substantial amount of text. A 35694 copy that is not "Transparent" is called "Opaque". 35695 35696 Examples of suitable formats for Transparent copies include plain 35697 ASCII without markup, Texinfo input format, LaTeX input format, 35698 SGML or XML using a publicly available DTD, and 35699 standard-conforming simple HTML, PostScript or PDF designed for 35700 human modification. Examples of transparent image formats include 35701 PNG, XCF and JPG. Opaque formats include proprietary formats that 35702 can be read and edited only by proprietary word processors, SGML or 35703 XML for which the DTD and/or processing tools are not generally 35704 available, and the machine-generated HTML, PostScript or PDF 35705 produced by some word processors for output purposes only. 35706 35707 The "Title Page" means, for a printed book, the title page itself, 35708 plus such following pages as are needed to hold, legibly, the 35709 material this License requires to appear in the title page. For 35710 works in formats which do not have any title page as such, "Title 35711 Page" means the text near the most prominent appearance of the 35712 work's title, preceding the beginning of the body of the text. 35713 35714 A section "Entitled XYZ" means a named subunit of the Document 35715 whose title either is precisely XYZ or contains XYZ in parentheses 35716 following text that translates XYZ in another language. (Here XYZ 35717 stands for a specific section name mentioned below, such as 35718 "Acknowledgements", "Dedications", "Endorsements", or "History".) 35719 To "Preserve the Title" of such a section when you modify the 35720 Document means that it remains a section "Entitled XYZ" according 35721 to this definition. 35722 35723 The Document may include Warranty Disclaimers next to the notice 35724 which states that this License applies to the Document. These 35725 Warranty Disclaimers are considered to be included by reference in 35726 this License, but only as regards disclaiming warranties: any other 35727 implication that these Warranty Disclaimers may have is void and 35728 has no effect on the meaning of this License. 35729 35730 2. VERBATIM COPYING 35731 35732 You may copy and distribute the Document in any medium, either 35733 commercially or noncommercially, provided that this License, the 35734 copyright notices, and the license notice saying this License 35735 applies to the Document are reproduced in all copies, and that you 35736 add no other conditions whatsoever to those of this License. You 35737 may not use technical measures to obstruct or control the reading 35738 or further copying of the copies you make or distribute. However, 35739 you may accept compensation in exchange for copies. If you 35740 distribute a large enough number of copies you must also follow 35741 the conditions in section 3. 35742 35743 You may also lend copies, under the same conditions stated above, 35744 and you may publicly display copies. 35745 35746 3. COPYING IN QUANTITY 35747 35748 If you publish printed copies (or copies in media that commonly 35749 have printed covers) of the Document, numbering more than 100, and 35750 the Document's license notice requires Cover Texts, you must 35751 enclose the copies in covers that carry, clearly and legibly, all 35752 these Cover Texts: Front-Cover Texts on the front cover, and 35753 Back-Cover Texts on the back cover. Both covers must also clearly 35754 and legibly identify you as the publisher of these copies. The 35755 front cover must present the full title with all words of the 35756 title equally prominent and visible. You may add other material 35757 on the covers in addition. Copying with changes limited to the 35758 covers, as long as they preserve the title of the Document and 35759 satisfy these conditions, can be treated as verbatim copying in 35760 other respects. 35761 35762 If the required texts for either cover are too voluminous to fit 35763 legibly, you should put the first ones listed (as many as fit 35764 reasonably) on the actual cover, and continue the rest onto 35765 adjacent pages. 35766 35767 If you publish or distribute Opaque copies of the Document 35768 numbering more than 100, you must either include a 35769 machine-readable Transparent copy along with each Opaque copy, or 35770 state in or with each Opaque copy a computer-network location from 35771 which the general network-using public has access to download 35772 using public-standard network protocols a complete Transparent 35773 copy of the Document, free of added material. If you use the 35774 latter option, you must take reasonably prudent steps, when you 35775 begin distribution of Opaque copies in quantity, to ensure that 35776 this Transparent copy will remain thus accessible at the stated 35777 location until at least one year after the last time you 35778 distribute an Opaque copy (directly or through your agents or 35779 retailers) of that edition to the public. 35780 35781 It is requested, but not required, that you contact the authors of 35782 the Document well before redistributing any large number of 35783 copies, to give them a chance to provide you with an updated 35784 version of the Document. 35785 35786 4. MODIFICATIONS 35787 35788 You may copy and distribute a Modified Version of the Document 35789 under the conditions of sections 2 and 3 above, provided that you 35790 release the Modified Version under precisely this License, with 35791 the Modified Version filling the role of the Document, thus 35792 licensing distribution and modification of the Modified Version to 35793 whoever possesses a copy of it. In addition, you must do these 35794 things in the Modified Version: 35795 35796 A. Use in the Title Page (and on the covers, if any) a title 35797 distinct from that of the Document, and from those of 35798 previous versions (which should, if there were any, be listed 35799 in the History section of the Document). You may use the 35800 same title as a previous version if the original publisher of 35801 that version gives permission. 35802 35803 B. List on the Title Page, as authors, one or more persons or 35804 entities responsible for authorship of the modifications in 35805 the Modified Version, together with at least five of the 35806 principal authors of the Document (all of its principal 35807 authors, if it has fewer than five), unless they release you 35808 from this requirement. 35809 35810 C. State on the Title page the name of the publisher of the 35811 Modified Version, as the publisher. 35812 35813 D. Preserve all the copyright notices of the Document. 35814 35815 E. Add an appropriate copyright notice for your modifications 35816 adjacent to the other copyright notices. 35817 35818 F. Include, immediately after the copyright notices, a license 35819 notice giving the public permission to use the Modified 35820 Version under the terms of this License, in the form shown in 35821 the Addendum below. 35822 35823 G. Preserve in that license notice the full lists of Invariant 35824 Sections and required Cover Texts given in the Document's 35825 license notice. 35826 35827 H. Include an unaltered copy of this License. 35828 35829 I. Preserve the section Entitled "History", Preserve its Title, 35830 and add to it an item stating at least the title, year, new 35831 authors, and publisher of the Modified Version as given on 35832 the Title Page. If there is no section Entitled "History" in 35833 the Document, create one stating the title, year, authors, 35834 and publisher of the Document as given on its Title Page, 35835 then add an item describing the Modified Version as stated in 35836 the previous sentence. 35837 35838 J. Preserve the network location, if any, given in the Document 35839 for public access to a Transparent copy of the Document, and 35840 likewise the network locations given in the Document for 35841 previous versions it was based on. These may be placed in 35842 the "History" section. You may omit a network location for a 35843 work that was published at least four years before the 35844 Document itself, or if the original publisher of the version 35845 it refers to gives permission. 35846 35847 K. For any section Entitled "Acknowledgements" or "Dedications", 35848 Preserve the Title of the section, and preserve in the 35849 section all the substance and tone of each of the contributor 35850 acknowledgements and/or dedications given therein. 35851 35852 L. Preserve all the Invariant Sections of the Document, 35853 unaltered in their text and in their titles. Section numbers 35854 or the equivalent are not considered part of the section 35855 titles. 35856 35857 M. Delete any section Entitled "Endorsements". Such a section 35858 may not be included in the Modified Version. 35859 35860 N. Do not retitle any existing section to be Entitled 35861 "Endorsements" or to conflict in title with any Invariant 35862 Section. 35863 35864 O. Preserve any Warranty Disclaimers. 35865 35866 If the Modified Version includes new front-matter sections or 35867 appendices that qualify as Secondary Sections and contain no 35868 material copied from the Document, you may at your option 35869 designate some or all of these sections as invariant. To do this, 35870 add their titles to the list of Invariant Sections in the Modified 35871 Version's license notice. These titles must be distinct from any 35872 other section titles. 35873 35874 You may add a section Entitled "Endorsements", provided it contains 35875 nothing but endorsements of your Modified Version by various 35876 parties--for example, statements of peer review or that the text 35877 has been approved by an organization as the authoritative 35878 definition of a standard. 35879 35880 You may add a passage of up to five words as a Front-Cover Text, 35881 and a passage of up to 25 words as a Back-Cover Text, to the end 35882 of the list of Cover Texts in the Modified Version. Only one 35883 passage of Front-Cover Text and one of Back-Cover Text may be 35884 added by (or through arrangements made by) any one entity. If the 35885 Document already includes a cover text for the same cover, 35886 previously added by you or by arrangement made by the same entity 35887 you are acting on behalf of, you may not add another; but you may 35888 replace the old one, on explicit permission from the previous 35889 publisher that added the old one. 35890 35891 The author(s) and publisher(s) of the Document do not by this 35892 License give permission to use their names for publicity for or to 35893 assert or imply endorsement of any Modified Version. 35894 35895 5. COMBINING DOCUMENTS 35896 35897 You may combine the Document with other documents released under 35898 this License, under the terms defined in section 4 above for 35899 modified versions, provided that you include in the combination 35900 all of the Invariant Sections of all of the original documents, 35901 unmodified, and list them all as Invariant Sections of your 35902 combined work in its license notice, and that you preserve all 35903 their Warranty Disclaimers. 35904 35905 The combined work need only contain one copy of this License, and 35906 multiple identical Invariant Sections may be replaced with a single 35907 copy. If there are multiple Invariant Sections with the same name 35908 but different contents, make the title of each such section unique 35909 by adding at the end of it, in parentheses, the name of the 35910 original author or publisher of that section if known, or else a 35911 unique number. Make the same adjustment to the section titles in 35912 the list of Invariant Sections in the license notice of the 35913 combined work. 35914 35915 In the combination, you must combine any sections Entitled 35916 "History" in the various original documents, forming one section 35917 Entitled "History"; likewise combine any sections Entitled 35918 "Acknowledgements", and any sections Entitled "Dedications". You 35919 must delete all sections Entitled "Endorsements." 35920 35921 6. COLLECTIONS OF DOCUMENTS 35922 35923 You may make a collection consisting of the Document and other 35924 documents released under this License, and replace the individual 35925 copies of this License in the various documents with a single copy 35926 that is included in the collection, provided that you follow the 35927 rules of this License for verbatim copying of each of the 35928 documents in all other respects. 35929 35930 You may extract a single document from such a collection, and 35931 distribute it individually under this License, provided you insert 35932 a copy of this License into the extracted document, and follow 35933 this License in all other respects regarding verbatim copying of 35934 that document. 35935 35936 7. AGGREGATION WITH INDEPENDENT WORKS 35937 35938 A compilation of the Document or its derivatives with other 35939 separate and independent documents or works, in or on a volume of 35940 a storage or distribution medium, is called an "aggregate" if the 35941 copyright resulting from the compilation is not used to limit the 35942 legal rights of the compilation's users beyond what the individual 35943 works permit. When the Document is included in an aggregate, this 35944 License does not apply to the other works in the aggregate which 35945 are not themselves derivative works of the Document. 35946 35947 If the Cover Text requirement of section 3 is applicable to these 35948 copies of the Document, then if the Document is less than one half 35949 of the entire aggregate, the Document's Cover Texts may be placed 35950 on covers that bracket the Document within the aggregate, or the 35951 electronic equivalent of covers if the Document is in electronic 35952 form. Otherwise they must appear on printed covers that bracket 35953 the whole aggregate. 35954 35955 8. TRANSLATION 35956 35957 Translation is considered a kind of modification, so you may 35958 distribute translations of the Document under the terms of section 35959 4. Replacing Invariant Sections with translations requires special 35960 permission from their copyright holders, but you may include 35961 translations of some or all Invariant Sections in addition to the 35962 original versions of these Invariant Sections. You may include a 35963 translation of this License, and all the license notices in the 35964 Document, and any Warranty Disclaimers, provided that you also 35965 include the original English version of this License and the 35966 original versions of those notices and disclaimers. In case of a 35967 disagreement between the translation and the original version of 35968 this License or a notice or disclaimer, the original version will 35969 prevail. 35970 35971 If a section in the Document is Entitled "Acknowledgements", 35972 "Dedications", or "History", the requirement (section 4) to 35973 Preserve its Title (section 1) will typically require changing the 35974 actual title. 35975 35976 9. TERMINATION 35977 35978 You may not copy, modify, sublicense, or distribute the Document 35979 except as expressly provided for under this License. Any other 35980 attempt to copy, modify, sublicense or distribute the Document is 35981 void, and will automatically terminate your rights under this 35982 License. However, parties who have received copies, or rights, 35983 from you under this License will not have their licenses 35984 terminated so long as such parties remain in full compliance. 35985 35986 10. FUTURE REVISIONS OF THIS LICENSE 35987 35988 The Free Software Foundation may publish new, revised versions of 35989 the GNU Free Documentation License from time to time. Such new 35990 versions will be similar in spirit to the present version, but may 35991 differ in detail to address new problems or concerns. See 35992 `http://www.gnu.org/copyleft/'. 35993 35994 Each version of the License is given a distinguishing version 35995 number. If the Document specifies that a particular numbered 35996 version of this License "or any later version" applies to it, you 35997 have the option of following the terms and conditions either of 35998 that specified version or of any later version that has been 35999 published (not as a draft) by the Free Software Foundation. If 36000 the Document does not specify a version number of this License, 36001 you may choose any version ever published (not as a draft) by the 36002 Free Software Foundation. 36003 36004 ADDENDUM: How to use this License for your documents 36005 ==================================================== 36006 36007 To use this License in a document you have written, include a copy of 36008 the License in the document and put the following copyright and license 36009 notices just after the title page: 36010 36011 Copyright (C) YEAR YOUR NAME. 36012 Permission is granted to copy, distribute and/or modify this document 36013 under the terms of the GNU Free Documentation License, Version 1.2 36014 or any later version published by the Free Software Foundation; 36015 with no Invariant Sections, no Front-Cover Texts, and no Back-Cover 36016 Texts. A copy of the license is included in the section entitled ``GNU 36017 Free Documentation License''. 36018 36019 If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, 36020 replace the "with...Texts." line with this: 36021 36022 with the Invariant Sections being LIST THEIR TITLES, with 36023 the Front-Cover Texts being LIST, and with the Back-Cover Texts 36024 being LIST. 36025 36026 If you have Invariant Sections without Cover Texts, or some other 36027 combination of the three, merge those two alternatives to suit the 36028 situation. 36029 36030 If your document contains nontrivial examples of program code, we 36031 recommend releasing these examples in parallel under your choice of 36032 free software license, such as the GNU General Public License, to 36033 permit their use in free software. 36034 36035 36036 File: gccint.info, Node: Contributors, Next: Option Index, Prev: GNU Free Documentation License, Up: Top 36037 36038 Contributors to GCC 36039 ******************* 36040 36041 The GCC project would like to thank its many contributors. Without 36042 them the project would not have been nearly as successful as it has 36043 been. Any omissions in this list are accidental. Feel free to contact 36044 <law (a] redhat.com> or <gerald (a] pfeifer.com> if you have been left out or 36045 some of your contributions are not listed. Please keep this list in 36046 alphabetical order. 36047 36048 * Analog Devices helped implement the support for complex data types 36049 and iterators. 36050 36051 * John David Anglin for threading-related fixes and improvements to 36052 libstdc++-v3, and the HP-UX port. 36053 36054 * James van Artsdalen wrote the code that makes efficient use of the 36055 Intel 80387 register stack. 36056 36057 * Abramo and Roberto Bagnara for the SysV68 Motorola 3300 Delta 36058 Series port. 36059 36060 * Alasdair Baird for various bug fixes. 36061 36062 * Giovanni Bajo for analyzing lots of complicated C++ problem 36063 reports. 36064 36065 * Peter Barada for his work to improve code generation for new 36066 ColdFire cores. 36067 36068 * Gerald Baumgartner added the signature extension to the C++ front 36069 end. 36070 36071 * Godmar Back for his Java improvements and encouragement. 36072 36073 * Scott Bambrough for help porting the Java compiler. 36074 36075 * Wolfgang Bangerth for processing tons of bug reports. 36076 36077 * Jon Beniston for his Microsoft Windows port of Java. 36078 36079 * Daniel Berlin for better DWARF2 support, faster/better 36080 optimizations, improved alias analysis, plus migrating GCC to 36081 Bugzilla. 36082 36083 * Geoff Berry for his Java object serialization work and various 36084 patches. 36085 36086 * Uros Bizjak for the implementation of x87 math built-in functions 36087 and for various middle end and i386 back end improvements and bug 36088 fixes. 36089 36090 * Eric Blake for helping to make GCJ and libgcj conform to the 36091 specifications. 36092 36093 * Janne Blomqvist for contributions to GNU Fortran. 36094 36095 * Segher Boessenkool for various fixes. 36096 36097 * Hans-J. Boehm for his garbage collector, IA-64 libffi port, and 36098 other Java work. 36099 36100 * Neil Booth for work on cpplib, lang hooks, debug hooks and other 36101 miscellaneous clean-ups. 36102 36103 * Steven Bosscher for integrating the GNU Fortran front end into GCC 36104 and for contributing to the tree-ssa branch. 36105 36106 * Eric Botcazou for fixing middle- and backend bugs left and right. 36107 36108 * Per Bothner for his direction via the steering committee and 36109 various improvements to the infrastructure for supporting new 36110 languages. Chill front end implementation. Initial 36111 implementations of cpplib, fix-header, config.guess, libio, and 36112 past C++ library (libg++) maintainer. Dreaming up, designing and 36113 implementing much of GCJ. 36114 36115 * Devon Bowen helped port GCC to the Tahoe. 36116 36117 * Don Bowman for mips-vxworks contributions. 36118 36119 * Dave Brolley for work on cpplib and Chill. 36120 36121 * Paul Brook for work on the ARM architecture and maintaining GNU 36122 Fortran. 36123 36124 * Robert Brown implemented the support for Encore 32000 systems. 36125 36126 * Christian Bruel for improvements to local store elimination. 36127 36128 * Herman A.J. ten Brugge for various fixes. 36129 36130 * Joerg Brunsmann for Java compiler hacking and help with the GCJ 36131 FAQ. 36132 36133 * Joe Buck for his direction via the steering committee. 36134 36135 * Craig Burley for leadership of the G77 Fortran effort. 36136 36137 * Stephan Buys for contributing Doxygen notes for libstdc++. 36138 36139 * Paolo Carlini for libstdc++ work: lots of efficiency improvements 36140 to the C++ strings, streambufs and formatted I/O, hard detective 36141 work on the frustrating localization issues, and keeping up with 36142 the problem reports. 36143 36144 * John Carr for his alias work, SPARC hacking, infrastructure 36145 improvements, previous contributions to the steering committee, 36146 loop optimizations, etc. 36147 36148 * Stephane Carrez for 68HC11 and 68HC12 ports. 36149 36150 * Steve Chamberlain for support for the Renesas SH and H8 processors 36151 and the PicoJava processor, and for GCJ config fixes. 36152 36153 * Glenn Chambers for help with the GCJ FAQ. 36154 36155 * John-Marc Chandonia for various libgcj patches. 36156 36157 * Scott Christley for his Objective-C contributions. 36158 36159 * Eric Christopher for his Java porting help and clean-ups. 36160 36161 * Branko Cibej for more warning contributions. 36162 36163 * The GNU Classpath project for all of their merged runtime code. 36164 36165 * Nick Clifton for arm, mcore, fr30, v850, m32r work, `--help', and 36166 other random hacking. 36167 36168 * Michael Cook for libstdc++ cleanup patches to reduce warnings. 36169 36170 * R. Kelley Cook for making GCC buildable from a read-only directory 36171 as well as other miscellaneous build process and documentation 36172 clean-ups. 36173 36174 * Ralf Corsepius for SH testing and minor bug fixing. 36175 36176 * Stan Cox for care and feeding of the x86 port and lots of behind 36177 the scenes hacking. 36178 36179 * Alex Crain provided changes for the 3b1. 36180 36181 * Ian Dall for major improvements to the NS32k port. 36182 36183 * Paul Dale for his work to add uClinux platform support to the m68k 36184 backend. 36185 36186 * Dario Dariol contributed the four varieties of sample programs 36187 that print a copy of their source. 36188 36189 * Russell Davidson for fstream and stringstream fixes in libstdc++. 36190 36191 * Bud Davis for work on the G77 and GNU Fortran compilers. 36192 36193 * Mo DeJong for GCJ and libgcj bug fixes. 36194 36195 * DJ Delorie for the DJGPP port, build and libiberty maintenance, 36196 various bug fixes, and the M32C port. 36197 36198 * Arnaud Desitter for helping to debug GNU Fortran. 36199 36200 * Gabriel Dos Reis for contributions to G++, contributions and 36201 maintenance of GCC diagnostics infrastructure, libstdc++-v3, 36202 including `valarray<>', `complex<>', maintaining the numerics 36203 library (including that pesky `<limits>' :-) and keeping 36204 up-to-date anything to do with numbers. 36205 36206 * Ulrich Drepper for his work on glibc, testing of GCC using glibc, 36207 ISO C99 support, CFG dumping support, etc., plus support of the 36208 C++ runtime libraries including for all kinds of C interface 36209 issues, contributing and maintaining `complex<>', sanity checking 36210 and disbursement, configuration architecture, libio maintenance, 36211 and early math work. 36212 36213 * Zdenek Dvorak for a new loop unroller and various fixes. 36214 36215 * Richard Earnshaw for his ongoing work with the ARM. 36216 36217 * David Edelsohn for his direction via the steering committee, 36218 ongoing work with the RS6000/PowerPC port, help cleaning up Haifa 36219 loop changes, doing the entire AIX port of libstdc++ with his bare 36220 hands, and for ensuring GCC properly keeps working on AIX. 36221 36222 * Kevin Ediger for the floating point formatting of num_put::do_put 36223 in libstdc++. 36224 36225 * Phil Edwards for libstdc++ work including configuration hackery, 36226 documentation maintainer, chief breaker of the web pages, the 36227 occasional iostream bug fix, and work on shared library symbol 36228 versioning. 36229 36230 * Paul Eggert for random hacking all over GCC. 36231 36232 * Mark Elbrecht for various DJGPP improvements, and for libstdc++ 36233 configuration support for locales and fstream-related fixes. 36234 36235 * Vadim Egorov for libstdc++ fixes in strings, streambufs, and 36236 iostreams. 36237 36238 * Christian Ehrhardt for dealing with bug reports. 36239 36240 * Ben Elliston for his work to move the Objective-C runtime into its 36241 own subdirectory and for his work on autoconf. 36242 36243 * Revital Eres for work on the PowerPC 750CL port. 36244 36245 * Marc Espie for OpenBSD support. 36246 36247 * Doug Evans for much of the global optimization framework, arc, 36248 m32r, and SPARC work. 36249 36250 * Christopher Faylor for his work on the Cygwin port and for caring 36251 and feeding the gcc.gnu.org box and saving its users tons of spam. 36252 36253 * Fred Fish for BeOS support and Ada fixes. 36254 36255 * Ivan Fontes Garcia for the Portuguese translation of the GCJ FAQ. 36256 36257 * Peter Gerwinski for various bug fixes and the Pascal front end. 36258 36259 * Kaveh R. Ghazi for his direction via the steering committee, 36260 amazing work to make `-W -Wall -W* -Werror' useful, and 36261 continuously testing GCC on a plethora of platforms. Kaveh 36262 extends his gratitude to the CAIP Center at Rutgers University for 36263 providing him with computing resources to work on Free Software 36264 since the late 1980s. 36265 36266 * John Gilmore for a donation to the FSF earmarked improving GNU 36267 Java. 36268 36269 * Judy Goldberg for c++ contributions. 36270 36271 * Torbjorn Granlund for various fixes and the c-torture testsuite, 36272 multiply- and divide-by-constant optimization, improved long long 36273 support, improved leaf function register allocation, and his 36274 direction via the steering committee. 36275 36276 * Anthony Green for his `-Os' contributions and Java front end work. 36277 36278 * Stu Grossman for gdb hacking, allowing GCJ developers to debug 36279 Java code. 36280 36281 * Michael K. Gschwind contributed the port to the PDP-11. 36282 36283 * Ron Guilmette implemented the `protoize' and `unprotoize' tools, 36284 the support for Dwarf symbolic debugging information, and much of 36285 the support for System V Release 4. He has also worked heavily on 36286 the Intel 386 and 860 support. 36287 36288 * Mostafa Hagog for Swing Modulo Scheduling (SMS) and post reload 36289 GCSE. 36290 36291 * Bruno Haible for improvements in the runtime overhead for EH, new 36292 warnings and assorted bug fixes. 36293 36294 * Andrew Haley for his amazing Java compiler and library efforts. 36295 36296 * Chris Hanson assisted in making GCC work on HP-UX for the 9000 36297 series 300. 36298 36299 * Michael Hayes for various thankless work he's done trying to get 36300 the c30/c40 ports functional. Lots of loop and unroll 36301 improvements and fixes. 36302 36303 * Dara Hazeghi for wading through myriads of target-specific bug 36304 reports. 36305 36306 * Kate Hedstrom for staking the G77 folks with an initial testsuite. 36307 36308 * Richard Henderson for his ongoing SPARC, alpha, ia32, and ia64 36309 work, loop opts, and generally fixing lots of old problems we've 36310 ignored for years, flow rewrite and lots of further stuff, 36311 including reviewing tons of patches. 36312 36313 * Aldy Hernandez for working on the PowerPC port, SIMD support, and 36314 various fixes. 36315 36316 * Nobuyuki Hikichi of Software Research Associates, Tokyo, 36317 contributed the support for the Sony NEWS machine. 36318 36319 * Kazu Hirata for caring and feeding the Renesas H8/300 port and 36320 various fixes. 36321 36322 * Katherine Holcomb for work on GNU Fortran. 36323 36324 * Manfred Hollstein for his ongoing work to keep the m88k alive, lots 36325 of testing and bug fixing, particularly of GCC configury code. 36326 36327 * Steve Holmgren for MachTen patches. 36328 36329 * Jan Hubicka for his x86 port improvements. 36330 36331 * Falk Hueffner for working on C and optimization bug reports. 36332 36333 * Bernardo Innocenti for his m68k work, including merging of 36334 ColdFire improvements and uClinux support. 36335 36336 * Christian Iseli for various bug fixes. 36337 36338 * Kamil Iskra for general m68k hacking. 36339 36340 * Lee Iverson for random fixes and MIPS testing. 36341 36342 * Andreas Jaeger for testing and benchmarking of GCC and various bug 36343 fixes. 36344 36345 * Jakub Jelinek for his SPARC work and sibling call optimizations as 36346 well as lots of bug fixes and test cases, and for improving the 36347 Java build system. 36348 36349 * Janis Johnson for ia64 testing and fixes, her quality improvement 36350 sidetracks, and web page maintenance. 36351 36352 * Kean Johnston for SCO OpenServer support and various fixes. 36353 36354 * Tim Josling for the sample language treelang based originally on 36355 Richard Kenner's "toy" language. 36356 36357 * Nicolai Josuttis for additional libstdc++ documentation. 36358 36359 * Klaus Kaempf for his ongoing work to make alpha-vms a viable 36360 target. 36361 36362 * Steven G. Kargl for work on GNU Fortran. 36363 36364 * David Kashtan of SRI adapted GCC to VMS. 36365 36366 * Ryszard Kabatek for many, many libstdc++ bug fixes and 36367 optimizations of strings, especially member functions, and for 36368 auto_ptr fixes. 36369 36370 * Geoffrey Keating for his ongoing work to make the PPC work for 36371 GNU/Linux and his automatic regression tester. 36372 36373 * Brendan Kehoe for his ongoing work with G++ and for a lot of early 36374 work in just about every part of libstdc++. 36375 36376 * Oliver M. Kellogg of Deutsche Aerospace contributed the port to the 36377 MIL-STD-1750A. 36378 36379 * Richard Kenner of the New York University Ultracomputer Research 36380 Laboratory wrote the machine descriptions for the AMD 29000, the 36381 DEC Alpha, the IBM RT PC, and the IBM RS/6000 as well as the 36382 support for instruction attributes. He also made changes to 36383 better support RISC processors including changes to common 36384 subexpression elimination, strength reduction, function calling 36385 sequence handling, and condition code support, in addition to 36386 generalizing the code for frame pointer elimination and delay slot 36387 scheduling. Richard Kenner was also the head maintainer of GCC 36388 for several years. 36389 36390 * Mumit Khan for various contributions to the Cygwin and Mingw32 36391 ports and maintaining binary releases for Microsoft Windows hosts, 36392 and for massive libstdc++ porting work to Cygwin/Mingw32. 36393 36394 * Robin Kirkham for cpu32 support. 36395 36396 * Mark Klein for PA improvements. 36397 36398 * Thomas Koenig for various bug fixes. 36399 36400 * Bruce Korb for the new and improved fixincludes code. 36401 36402 * Benjamin Kosnik for his G++ work and for leading the libstdc++-v3 36403 effort. 36404 36405 * Charles LaBrec contributed the support for the Integrated Solutions 36406 68020 system. 36407 36408 * Asher Langton and Mike Kumbera for contributing Cray pointer 36409 support to GNU Fortran, and for other GNU Fortran improvements. 36410 36411 * Jeff Law for his direction via the steering committee, 36412 coordinating the entire egcs project and GCC 2.95, rolling out 36413 snapshots and releases, handling merges from GCC2, reviewing tons 36414 of patches that might have fallen through the cracks else, and 36415 random but extensive hacking. 36416 36417 * Marc Lehmann for his direction via the steering committee and 36418 helping with analysis and improvements of x86 performance. 36419 36420 * Victor Leikehman for work on GNU Fortran. 36421 36422 * Ted Lemon wrote parts of the RTL reader and printer. 36423 36424 * Kriang Lerdsuwanakij for C++ improvements including template as 36425 template parameter support, and many C++ fixes. 36426 36427 * Warren Levy for tremendous work on libgcj (Java Runtime Library) 36428 and random work on the Java front end. 36429 36430 * Alain Lichnewsky ported GCC to the MIPS CPU. 36431 36432 * Oskar Liljeblad for hacking on AWT and his many Java bug reports 36433 and patches. 36434 36435 * Robert Lipe for OpenServer support, new testsuites, testing, etc. 36436 36437 * Chen Liqin for various S+core related fixes/improvement, and for 36438 maintaining the S+core port. 36439 36440 * Weiwen Liu for testing and various bug fixes. 36441 36442 * Manuel Lo'pez-Iba'n~ez for improving `-Wconversion' and many other 36443 diagnostics fixes and improvements. 36444 36445 * Dave Love for his ongoing work with the Fortran front end and 36446 runtime libraries. 36447 36448 * Martin von Lo"wis for internal consistency checking infrastructure, 36449 various C++ improvements including namespace support, and tons of 36450 assistance with libstdc++/compiler merges. 36451 36452 * H.J. Lu for his previous contributions to the steering committee, 36453 many x86 bug reports, prototype patches, and keeping the GNU/Linux 36454 ports working. 36455 36456 * Greg McGary for random fixes and (someday) bounded pointers. 36457 36458 * Andrew MacLeod for his ongoing work in building a real EH system, 36459 various code generation improvements, work on the global 36460 optimizer, etc. 36461 36462 * Vladimir Makarov for hacking some ugly i960 problems, PowerPC 36463 hacking improvements to compile-time performance, overall 36464 knowledge and direction in the area of instruction scheduling, and 36465 design and implementation of the automaton based instruction 36466 scheduler. 36467 36468 * Bob Manson for his behind the scenes work on dejagnu. 36469 36470 * Philip Martin for lots of libstdc++ string and vector iterator 36471 fixes and improvements, and string clean up and testsuites. 36472 36473 * All of the Mauve project contributors, for Java test code. 36474 36475 * Bryce McKinlay for numerous GCJ and libgcj fixes and improvements. 36476 36477 * Adam Megacz for his work on the Microsoft Windows port of GCJ. 36478 36479 * Michael Meissner for LRS framework, ia32, m32r, v850, m88k, MIPS, 36480 powerpc, haifa, ECOFF debug support, and other assorted hacking. 36481 36482 * Jason Merrill for his direction via the steering committee and 36483 leading the G++ effort. 36484 36485 * Martin Michlmayr for testing GCC on several architectures using the 36486 entire Debian archive. 36487 36488 * David Miller for his direction via the steering committee, lots of 36489 SPARC work, improvements in jump.c and interfacing with the Linux 36490 kernel developers. 36491 36492 * Gary Miller ported GCC to Charles River Data Systems machines. 36493 36494 * Alfred Minarik for libstdc++ string and ios bug fixes, and turning 36495 the entire libstdc++ testsuite namespace-compatible. 36496 36497 * Mark Mitchell for his direction via the steering committee, 36498 mountains of C++ work, load/store hoisting out of loops, alias 36499 analysis improvements, ISO C `restrict' support, and serving as 36500 release manager for GCC 3.x. 36501 36502 * Alan Modra for various GNU/Linux bits and testing. 36503 36504 * Toon Moene for his direction via the steering committee, Fortran 36505 maintenance, and his ongoing work to make us make Fortran run fast. 36506 36507 * Jason Molenda for major help in the care and feeding of all the 36508 services on the gcc.gnu.org (formerly egcs.cygnus.com) 36509 machine--mail, web services, ftp services, etc etc. Doing all 36510 this work on scrap paper and the backs of envelopes would have 36511 been... difficult. 36512 36513 * Catherine Moore for fixing various ugly problems we have sent her 36514 way, including the haifa bug which was killing the Alpha & PowerPC 36515 Linux kernels. 36516 36517 * Mike Moreton for his various Java patches. 36518 36519 * David Mosberger-Tang for various Alpha improvements, and for the 36520 initial IA-64 port. 36521 36522 * Stephen Moshier contributed the floating point emulator that 36523 assists in cross-compilation and permits support for floating 36524 point numbers wider than 64 bits and for ISO C99 support. 36525 36526 * Bill Moyer for his behind the scenes work on various issues. 36527 36528 * Philippe De Muyter for his work on the m68k port. 36529 36530 * Joseph S. Myers for his work on the PDP-11 port, format checking 36531 and ISO C99 support, and continuous emphasis on (and contributions 36532 to) documentation. 36533 36534 * Nathan Myers for his work on libstdc++-v3: architecture and 36535 authorship through the first three snapshots, including 36536 implementation of locale infrastructure, string, shadow C headers, 36537 and the initial project documentation (DESIGN, CHECKLIST, and so 36538 forth). Later, more work on MT-safe string and shadow headers. 36539 36540 * Felix Natter for documentation on porting libstdc++. 36541 36542 * Nathanael Nerode for cleaning up the configuration/build process. 36543 36544 * NeXT, Inc. donated the front end that supports the Objective-C 36545 language. 36546 36547 * Hans-Peter Nilsson for the CRIS and MMIX ports, improvements to 36548 the search engine setup, various documentation fixes and other 36549 small fixes. 36550 36551 * Geoff Noer for his work on getting cygwin native builds working. 36552 36553 * Diego Novillo for his work on Tree SSA, OpenMP, SPEC performance 36554 tracking web pages, GIMPLE tuples, and assorted fixes. 36555 36556 * David O'Brien for the FreeBSD/alpha, FreeBSD/AMD x86-64, 36557 FreeBSD/ARM, FreeBSD/PowerPC, and FreeBSD/SPARC64 ports and 36558 related infrastructure improvements. 36559 36560 * Alexandre Oliva for various build infrastructure improvements, 36561 scripts and amazing testing work, including keeping libtool issues 36562 sane and happy. 36563 36564 * Stefan Olsson for work on mt_alloc. 36565 36566 * Melissa O'Neill for various NeXT fixes. 36567 36568 * Rainer Orth for random MIPS work, including improvements to GCC's 36569 o32 ABI support, improvements to dejagnu's MIPS support, Java 36570 configuration clean-ups and porting work, etc. 36571 36572 * Hartmut Penner for work on the s390 port. 36573 36574 * Paul Petersen wrote the machine description for the Alliant FX/8. 36575 36576 * Alexandre Petit-Bianco for implementing much of the Java compiler 36577 and continued Java maintainership. 36578 36579 * Matthias Pfaller for major improvements to the NS32k port. 36580 36581 * Gerald Pfeifer for his direction via the steering committee, 36582 pointing out lots of problems we need to solve, maintenance of the 36583 web pages, and taking care of documentation maintenance in general. 36584 36585 * Andrew Pinski for processing bug reports by the dozen. 36586 36587 * Ovidiu Predescu for his work on the Objective-C front end and 36588 runtime libraries. 36589 36590 * Jerry Quinn for major performance improvements in C++ formatted 36591 I/O. 36592 36593 * Ken Raeburn for various improvements to checker, MIPS ports and 36594 various cleanups in the compiler. 36595 36596 * Rolf W. Rasmussen for hacking on AWT. 36597 36598 * David Reese of Sun Microsystems contributed to the Solaris on 36599 PowerPC port. 36600 36601 * Volker Reichelt for keeping up with the problem reports. 36602 36603 * Joern Rennecke for maintaining the sh port, loop, regmove & reload 36604 hacking. 36605 36606 * Loren J. Rittle for improvements to libstdc++-v3 including the 36607 FreeBSD port, threading fixes, thread-related configury changes, 36608 critical threading documentation, and solutions to really tricky 36609 I/O problems, as well as keeping GCC properly working on FreeBSD 36610 and continuous testing. 36611 36612 * Craig Rodrigues for processing tons of bug reports. 36613 36614 * Ola Ro"nnerup for work on mt_alloc. 36615 36616 * Gavin Romig-Koch for lots of behind the scenes MIPS work. 36617 36618 * David Ronis inspired and encouraged Craig to rewrite the G77 36619 documentation in texinfo format by contributing a first pass at a 36620 translation of the old `g77-0.5.16/f/DOC' file. 36621 36622 * Ken Rose for fixes to GCC's delay slot filling code. 36623 36624 * Paul Rubin wrote most of the preprocessor. 36625 36626 * Pe'tur Runo'lfsson for major performance improvements in C++ 36627 formatted I/O and large file support in C++ filebuf. 36628 36629 * Chip Salzenberg for libstdc++ patches and improvements to locales, 36630 traits, Makefiles, libio, libtool hackery, and "long long" support. 36631 36632 * Juha Sarlin for improvements to the H8 code generator. 36633 36634 * Greg Satz assisted in making GCC work on HP-UX for the 9000 series 36635 300. 36636 36637 * Roger Sayle for improvements to constant folding and GCC's RTL 36638 optimizers as well as for fixing numerous bugs. 36639 36640 * Bradley Schatz for his work on the GCJ FAQ. 36641 36642 * Peter Schauer wrote the code to allow debugging to work on the 36643 Alpha. 36644 36645 * William Schelter did most of the work on the Intel 80386 support. 36646 36647 * Tobias Schlu"ter for work on GNU Fortran. 36648 36649 * Bernd Schmidt for various code generation improvements and major 36650 work in the reload pass as well a serving as release manager for 36651 GCC 2.95.3. 36652 36653 * Peter Schmid for constant testing of libstdc++--especially 36654 application testing, going above and beyond what was requested for 36655 the release criteria--and libstdc++ header file tweaks. 36656 36657 * Jason Schroeder for jcf-dump patches. 36658 36659 * Andreas Schwab for his work on the m68k port. 36660 36661 * Lars Segerlund for work on GNU Fortran. 36662 36663 * Joel Sherrill for his direction via the steering committee, RTEMS 36664 contributions and RTEMS testing. 36665 36666 * Nathan Sidwell for many C++ fixes/improvements. 36667 36668 * Jeffrey Siegal for helping RMS with the original design of GCC, 36669 some code which handles the parse tree and RTL data structures, 36670 constant folding and help with the original VAX & m68k ports. 36671 36672 * Kenny Simpson for prompting libstdc++ fixes due to defect reports 36673 from the LWG (thereby keeping GCC in line with updates from the 36674 ISO). 36675 36676 * Franz Sirl for his ongoing work with making the PPC port stable 36677 for GNU/Linux. 36678 36679 * Andrey Slepuhin for assorted AIX hacking. 36680 36681 * Trevor Smigiel for contributing the SPU port. 36682 36683 * Christopher Smith did the port for Convex machines. 36684 36685 * Danny Smith for his major efforts on the Mingw (and Cygwin) ports. 36686 36687 * Randy Smith finished the Sun FPA support. 36688 36689 * Scott Snyder for queue, iterator, istream, and string fixes and 36690 libstdc++ testsuite entries. Also for providing the patch to G77 36691 to add rudimentary support for `INTEGER*1', `INTEGER*2', and 36692 `LOGICAL*1'. 36693 36694 * Brad Spencer for contributions to the GLIBCPP_FORCE_NEW technique. 36695 36696 * Richard Stallman, for writing the original GCC and launching the 36697 GNU project. 36698 36699 * Jan Stein of the Chalmers Computer Society provided support for 36700 Genix, as well as part of the 32000 machine description. 36701 36702 * Nigel Stephens for various mips16 related fixes/improvements. 36703 36704 * Jonathan Stone wrote the machine description for the Pyramid 36705 computer. 36706 36707 * Graham Stott for various infrastructure improvements. 36708 36709 * John Stracke for his Java HTTP protocol fixes. 36710 36711 * Mike Stump for his Elxsi port, G++ contributions over the years 36712 and more recently his vxworks contributions 36713 36714 * Jeff Sturm for Java porting help, bug fixes, and encouragement. 36715 36716 * Shigeya Suzuki for this fixes for the bsdi platforms. 36717 36718 * Ian Lance Taylor for his mips16 work, general configury hacking, 36719 fixincludes, etc. 36720 36721 * Holger Teutsch provided the support for the Clipper CPU. 36722 36723 * Gary Thomas for his ongoing work to make the PPC work for 36724 GNU/Linux. 36725 36726 * Philipp Thomas for random bug fixes throughout the compiler 36727 36728 * Jason Thorpe for thread support in libstdc++ on NetBSD. 36729 36730 * Kresten Krab Thorup wrote the run time support for the Objective-C 36731 language and the fantastic Java bytecode interpreter. 36732 36733 * Michael Tiemann for random bug fixes, the first instruction 36734 scheduler, initial C++ support, function integration, NS32k, SPARC 36735 and M88k machine description work, delay slot scheduling. 36736 36737 * Andreas Tobler for his work porting libgcj to Darwin. 36738 36739 * Teemu Torma for thread safe exception handling support. 36740 36741 * Leonard Tower wrote parts of the parser, RTL generator, and RTL 36742 definitions, and of the VAX machine description. 36743 36744 * Daniel Towner and Hariharan Sandanagobalane contributed and 36745 maintain the picoChip port. 36746 36747 * Tom Tromey for internationalization support and for his many Java 36748 contributions and libgcj maintainership. 36749 36750 * Lassi Tuura for improvements to config.guess to determine HP 36751 processor types. 36752 36753 * Petter Urkedal for libstdc++ CXXFLAGS, math, and algorithms fixes. 36754 36755 * Andy Vaught for the design and initial implementation of the GNU 36756 Fortran front end. 36757 36758 * Brent Verner for work with the libstdc++ cshadow files and their 36759 associated configure steps. 36760 36761 * Todd Vierling for contributions for NetBSD ports. 36762 36763 * Jonathan Wakely for contributing libstdc++ Doxygen notes and XHTML 36764 guidance. 36765 36766 * Dean Wakerley for converting the install documentation from HTML 36767 to texinfo in time for GCC 3.0. 36768 36769 * Krister Walfridsson for random bug fixes. 36770 36771 * Feng Wang for contributions to GNU Fortran. 36772 36773 * Stephen M. Webb for time and effort on making libstdc++ shadow 36774 files work with the tricky Solaris 8+ headers, and for pushing the 36775 build-time header tree. 36776 36777 * John Wehle for various improvements for the x86 code generator, 36778 related infrastructure improvements to help x86 code generation, 36779 value range propagation and other work, WE32k port. 36780 36781 * Ulrich Weigand for work on the s390 port. 36782 36783 * Zack Weinberg for major work on cpplib and various other bug fixes. 36784 36785 * Matt Welsh for help with Linux Threads support in GCJ. 36786 36787 * Urban Widmark for help fixing java.io. 36788 36789 * Mark Wielaard for new Java library code and his work integrating 36790 with Classpath. 36791 36792 * Dale Wiles helped port GCC to the Tahoe. 36793 36794 * Bob Wilson from Tensilica, Inc. for the Xtensa port. 36795 36796 * Jim Wilson for his direction via the steering committee, tackling 36797 hard problems in various places that nobody else wanted to work 36798 on, strength reduction and other loop optimizations. 36799 36800 * Paul Woegerer and Tal Agmon for the CRX port. 36801 36802 * Carlo Wood for various fixes. 36803 36804 * Tom Wood for work on the m88k port. 36805 36806 * Canqun Yang for work on GNU Fortran. 36807 36808 * Masanobu Yuhara of Fujitsu Laboratories implemented the machine 36809 description for the Tron architecture (specifically, the Gmicro). 36810 36811 * Kevin Zachmann helped port GCC to the Tahoe. 36812 36813 * Ayal Zaks for Swing Modulo Scheduling (SMS). 36814 36815 * Xiaoqiang Zhang for work on GNU Fortran. 36816 36817 * Gilles Zunino for help porting Java to Irix. 36818 36819 36820 The following people are recognized for their contributions to GNAT, 36821 the Ada front end of GCC: 36822 * Bernard Banner 36823 36824 * Romain Berrendonner 36825 36826 * Geert Bosch 36827 36828 * Emmanuel Briot 36829 36830 * Joel Brobecker 36831 36832 * Ben Brosgol 36833 36834 * Vincent Celier 36835 36836 * Arnaud Charlet 36837 36838 * Chien Chieng 36839 36840 * Cyrille Comar 36841 36842 * Cyrille Crozes 36843 36844 * Robert Dewar 36845 36846 * Gary Dismukes 36847 36848 * Robert Duff 36849 36850 * Ed Falis 36851 36852 * Ramon Fernandez 36853 36854 * Sam Figueroa 36855 36856 * Vasiliy Fofanov 36857 36858 * Michael Friess 36859 36860 * Franco Gasperoni 36861 36862 * Ted Giering 36863 36864 * Matthew Gingell 36865 36866 * Laurent Guerby 36867 36868 * Jerome Guitton 36869 36870 * Olivier Hainque 36871 36872 * Jerome Hugues 36873 36874 * Hristian Kirtchev 36875 36876 * Jerome Lambourg 36877 36878 * Bruno Leclerc 36879 36880 * Albert Lee 36881 36882 * Sean McNeil 36883 36884 * Javier Miranda 36885 36886 * Laurent Nana 36887 36888 * Pascal Obry 36889 36890 * Dong-Ik Oh 36891 36892 * Laurent Pautet 36893 36894 * Brett Porter 36895 36896 * Thomas Quinot 36897 36898 * Nicolas Roche 36899 36900 * Pat Rogers 36901 36902 * Jose Ruiz 36903 36904 * Douglas Rupp 36905 36906 * Sergey Rybin 36907 36908 * Gail Schenker 36909 36910 * Ed Schonberg 36911 36912 * Nicolas Setton 36913 36914 * Samuel Tardieu 36915 36916 36917 The following people are recognized for their contributions of new 36918 features, bug reports, testing and integration of classpath/libgcj for 36919 GCC version 4.1: 36920 * Lillian Angel for `JTree' implementation and lots Free Swing 36921 additions and bug fixes. 36922 36923 * Wolfgang Baer for `GapContent' bug fixes. 36924 36925 * Anthony Balkissoon for `JList', Free Swing 1.5 updates and mouse 36926 event fixes, lots of Free Swing work including `JTable' editing. 36927 36928 * Stuart Ballard for RMI constant fixes. 36929 36930 * Goffredo Baroncelli for `HTTPURLConnection' fixes. 36931 36932 * Gary Benson for `MessageFormat' fixes. 36933 36934 * Daniel Bonniot for `Serialization' fixes. 36935 36936 * Chris Burdess for lots of gnu.xml and http protocol fixes, `StAX' 36937 and `DOM xml:id' support. 36938 36939 * Ka-Hing Cheung for `TreePath' and `TreeSelection' fixes. 36940 36941 * Archie Cobbs for build fixes, VM interface updates, 36942 `URLClassLoader' updates. 36943 36944 * Kelley Cook for build fixes. 36945 36946 * Martin Cordova for Suggestions for better `SocketTimeoutException'. 36947 36948 * David Daney for `BitSet' bug fixes, `HttpURLConnection' rewrite 36949 and improvements. 36950 36951 * Thomas Fitzsimmons for lots of upgrades to the gtk+ AWT and Cairo 36952 2D support. Lots of imageio framework additions, lots of AWT and 36953 Free Swing bug fixes. 36954 36955 * Jeroen Frijters for `ClassLoader' and nio cleanups, serialization 36956 fixes, better `Proxy' support, bug fixes and IKVM integration. 36957 36958 * Santiago Gala for `AccessControlContext' fixes. 36959 36960 * Nicolas Geoffray for `VMClassLoader' and `AccessController' 36961 improvements. 36962 36963 * David Gilbert for `basic' and `metal' icon and plaf support and 36964 lots of documenting, Lots of Free Swing and metal theme additions. 36965 `MetalIconFactory' implementation. 36966 36967 * Anthony Green for `MIDI' framework, `ALSA' and `DSSI' providers. 36968 36969 * Andrew Haley for `Serialization' and `URLClassLoader' fixes, gcj 36970 build speedups. 36971 36972 * Kim Ho for `JFileChooser' implementation. 36973 36974 * Andrew John Hughes for `Locale' and net fixes, URI RFC2986 36975 updates, `Serialization' fixes, `Properties' XML support and 36976 generic branch work, VMIntegration guide update. 36977 36978 * Bastiaan Huisman for `TimeZone' bug fixing. 36979 36980 * Andreas Jaeger for mprec updates. 36981 36982 * Paul Jenner for better `-Werror' support. 36983 36984 * Ito Kazumitsu for `NetworkInterface' implementation and updates. 36985 36986 * Roman Kennke for `BoxLayout', `GrayFilter' and `SplitPane', plus 36987 bug fixes all over. Lots of Free Swing work including styled text. 36988 36989 * Simon Kitching for `String' cleanups and optimization suggestions. 36990 36991 * Michael Koch for configuration fixes, `Locale' updates, bug and 36992 build fixes. 36993 36994 * Guilhem Lavaux for configuration, thread and channel fixes and 36995 Kaffe integration. JCL native `Pointer' updates. Logger bug fixes. 36996 36997 * David Lichteblau for JCL support library global/local reference 36998 cleanups. 36999 37000 * Aaron Luchko for JDWP updates and documentation fixes. 37001 37002 * Ziga Mahkovec for `Graphics2D' upgraded to Cairo 0.5 and new regex 37003 features. 37004 37005 * Sven de Marothy for BMP imageio support, CSS and `TextLayout' 37006 fixes. `GtkImage' rewrite, 2D, awt, free swing and date/time fixes 37007 and implementing the Qt4 peers. 37008 37009 * Casey Marshall for crypto algorithm fixes, `FileChannel' lock, 37010 `SystemLogger' and `FileHandler' rotate implementations, NIO 37011 `FileChannel.map' support, security and policy updates. 37012 37013 * Bryce McKinlay for RMI work. 37014 37015 * Audrius Meskauskas for lots of Free Corba, RMI and HTML work plus 37016 testing and documenting. 37017 37018 * Kalle Olavi Niemitalo for build fixes. 37019 37020 * Rainer Orth for build fixes. 37021 37022 * Andrew Overholt for `File' locking fixes. 37023 37024 * Ingo Proetel for `Image', `Logger' and `URLClassLoader' updates. 37025 37026 * Olga Rodimina for `MenuSelectionManager' implementation. 37027 37028 * Jan Roehrich for `BasicTreeUI' and `JTree' fixes. 37029 37030 * Julian Scheid for documentation updates and gjdoc support. 37031 37032 * Christian Schlichtherle for zip fixes and cleanups. 37033 37034 * Robert Schuster for documentation updates and beans fixes, 37035 `TreeNode' enumerations and `ActionCommand' and various fixes, XML 37036 and URL, AWT and Free Swing bug fixes. 37037 37038 * Keith Seitz for lots of JDWP work. 37039 37040 * Christian Thalinger for 64-bit cleanups, Configuration and VM 37041 interface fixes and `CACAO' integration, `fdlibm' updates. 37042 37043 * Gael Thomas for `VMClassLoader' boot packages support suggestions. 37044 37045 * Andreas Tobler for Darwin and Solaris testing and fixing, `Qt4' 37046 support for Darwin/OS X, `Graphics2D' support, `gtk+' updates. 37047 37048 * Dalibor Topic for better `DEBUG' support, build cleanups and Kaffe 37049 integration. `Qt4' build infrastructure, `SHA1PRNG' and 37050 `GdkPixbugDecoder' updates. 37051 37052 * Tom Tromey for Eclipse integration, generics work, lots of bug 37053 fixes and gcj integration including coordinating The Big Merge. 37054 37055 * Mark Wielaard for bug fixes, packaging and release management, 37056 `Clipboard' implementation, system call interrupts and network 37057 timeouts and `GdkPixpufDecoder' fixes. 37058 37059 37060 In addition to the above, all of which also contributed time and 37061 energy in testing GCC, we would like to thank the following for their 37062 contributions to testing: 37063 37064 * Michael Abd-El-Malek 37065 37066 * Thomas Arend 37067 37068 * Bonzo Armstrong 37069 37070 * Steven Ashe 37071 37072 * Chris Baldwin 37073 37074 * David Billinghurst 37075 37076 * Jim Blandy 37077 37078 * Stephane Bortzmeyer 37079 37080 * Horst von Brand 37081 37082 * Frank Braun 37083 37084 * Rodney Brown 37085 37086 * Sidney Cadot 37087 37088 * Bradford Castalia 37089 37090 * Robert Clark 37091 37092 * Jonathan Corbet 37093 37094 * Ralph Doncaster 37095 37096 * Richard Emberson 37097 37098 * Levente Farkas 37099 37100 * Graham Fawcett 37101 37102 * Mark Fernyhough 37103 37104 * Robert A. French 37105 37106 * Jo"rgen Freyh 37107 37108 * Mark K. Gardner 37109 37110 * Charles-Antoine Gauthier 37111 37112 * Yung Shing Gene 37113 37114 * David Gilbert 37115 37116 * Simon Gornall 37117 37118 * Fred Gray 37119 37120 * John Griffin 37121 37122 * Patrik Hagglund 37123 37124 * Phil Hargett 37125 37126 * Amancio Hasty 37127 37128 * Takafumi Hayashi 37129 37130 * Bryan W. Headley 37131 37132 * Kevin B. Hendricks 37133 37134 * Joep Jansen 37135 37136 * Christian Joensson 37137 37138 * Michel Kern 37139 37140 * David Kidd 37141 37142 * Tobias Kuipers 37143 37144 * Anand Krishnaswamy 37145 37146 * A. O. V. Le Blanc 37147 37148 * llewelly 37149 37150 * Damon Love 37151 37152 * Brad Lucier 37153 37154 * Matthias Klose 37155 37156 * Martin Knoblauch 37157 37158 * Rick Lutowski 37159 37160 * Jesse Macnish 37161 37162 * Stefan Morrell 37163 37164 * Anon A. Mous 37165 37166 * Matthias Mueller 37167 37168 * Pekka Nikander 37169 37170 * Rick Niles 37171 37172 * Jon Olson 37173 37174 * Magnus Persson 37175 37176 * Chris Pollard 37177 37178 * Richard Polton 37179 37180 * Derk Reefman 37181 37182 * David Rees 37183 37184 * Paul Reilly 37185 37186 * Tom Reilly 37187 37188 * Torsten Rueger 37189 37190 * Danny Sadinoff 37191 37192 * Marc Schifer 37193 37194 * Erik Schnetter 37195 37196 * Wayne K. Schroll 37197 37198 * David Schuler 37199 37200 * Vin Shelton 37201 37202 * Tim Souder 37203 37204 * Adam Sulmicki 37205 37206 * Bill Thorson 37207 37208 * George Talbot 37209 37210 * Pedro A. M. Vazquez 37211 37212 * Gregory Warnes 37213 37214 * Ian Watson 37215 37216 * David E. Young 37217 37218 * And many others 37219 37220 And finally we'd like to thank everyone who uses the compiler, provides 37221 feedback and generally reminds us why we're doing this work in the first 37222 place. 37223 37224 37225 File: gccint.info, Node: Option Index, Next: Concept Index, Prev: Contributors, Up: Top 37226 37227 Option Index 37228 ************ 37229 37230 GCC's command line options are indexed here without any initial `-' or 37231 `--'. Where an option has both positive and negative forms (such as 37232 `-fOPTION' and `-fno-OPTION'), relevant entries in the manual are 37233 indexed under the most appropriate form; it may sometimes be useful to 37234 look up both forms. 37235 37236 [index] 37237 * Menu: 37238 37239 * msoft-float: Soft float library routines. 37240 (line 6) 37241 37242 37243 File: gccint.info, Node: Concept Index, Prev: Option Index, Up: Top 37244 37245 Concept Index 37246 ************* 37247 37248 [index] 37249 * Menu: 37250 37251 * ! in constraint: Multi-Alternative. (line 47) 37252 * # in constraint: Modifiers. (line 67) 37253 * # in template: Output Template. (line 66) 37254 * #pragma: Misc. (line 381) 37255 * % in constraint: Modifiers. (line 45) 37256 * % in GTY option: GTY Options. (line 18) 37257 * % in template: Output Template. (line 6) 37258 * & in constraint: Modifiers. (line 25) 37259 * ( <1>: Sections. (line 160) 37260 * ( <2>: Logical Operators. (line 124) 37261 * ( <3>: GIMPLE_CALL. (line 63) 37262 * ( <4>: Logical Operators. (line 150) 37263 * ( <5>: GIMPLE_ASM. (line 24) 37264 * (: Logical Operators. (line 128) 37265 * (nil): RTL Objects. (line 73) 37266 * * <1>: Scheduling. (line 246) 37267 * * <2>: Host Common. (line 17) 37268 * *: Scheduling. (line 268) 37269 * * in constraint: Modifiers. (line 72) 37270 * * in template: Output Statement. (line 29) 37271 * *gimple_assign_lhs_ptr: GIMPLE_ASSIGN. (line 54) 37272 * *gimple_assign_rhs1_ptr: GIMPLE_ASSIGN. (line 60) 37273 * *gimple_assign_rhs2_ptr: GIMPLE_ASSIGN. (line 81) 37274 * *gimple_call_arg_ptr: GIMPLE_CALL. (line 71) 37275 * *gimple_call_lhs_ptr: GIMPLE_CALL. (line 32) 37276 * *gimple_catch_types_ptr: GIMPLE_CATCH. (line 16) 37277 * *gimple_cdt_location_ptr: GIMPLE_CHANGE_DYNAMIC_TYPE. 37278 (line 28) 37279 * *gimple_cdt_new_type_ptr: GIMPLE_CHANGE_DYNAMIC_TYPE. 37280 (line 15) 37281 * *gimple_eh_filter_types_ptr: GIMPLE_EH_FILTER. (line 15) 37282 * *gimple_omp_critical_name_ptr: GIMPLE_OMP_CRITICAL. 37283 (line 16) 37284 * *gimple_omp_for_clauses_ptr: GIMPLE_OMP_FOR. (line 23) 37285 * *gimple_omp_for_final_ptr: GIMPLE_OMP_FOR. (line 54) 37286 * *gimple_omp_for_incr_ptr: GIMPLE_OMP_FOR. (line 64) 37287 * *gimple_omp_for_index_ptr: GIMPLE_OMP_FOR. (line 34) 37288 * *gimple_omp_for_initial_ptr: GIMPLE_OMP_FOR. (line 44) 37289 * *gimple_omp_parallel_child_fn_ptr: GIMPLE_OMP_PARALLEL. 37290 (line 46) 37291 * *gimple_omp_parallel_clauses_ptr: GIMPLE_OMP_PARALLEL. 37292 (line 34) 37293 * *gimple_omp_parallel_data_arg_ptr: GIMPLE_OMP_PARALLEL. 37294 (line 58) 37295 * *gimple_omp_sections_clauses_ptr: GIMPLE_OMP_SECTIONS. 37296 (line 33) 37297 * *gimple_omp_sections_control_ptr: GIMPLE_OMP_SECTIONS. 37298 (line 21) 37299 * *gimple_omp_single_clauses_ptr: GIMPLE_OMP_SINGLE. (line 17) 37300 * *gimple_op_ptr: Manipulating GIMPLE statements. 37301 (line 84) 37302 * *gimple_ops <1>: Logical Operators. (line 82) 37303 * *gimple_ops: Manipulating GIMPLE statements. 37304 (line 78) 37305 * *gimple_phi_result_ptr: GIMPLE_PHI. (line 22) 37306 * *gsi_stmt_ptr: Sequence iterators. (line 80) 37307 * *TARGET_GET_PCH_VALIDITY: PCH Target. (line 7) 37308 * + in constraint: Modifiers. (line 12) 37309 * -fsection-anchors <1>: Special Accessors. (line 106) 37310 * -fsection-anchors: Anchored Addresses. (line 6) 37311 * /c in RTL dump: Flags. (line 234) 37312 * /f in RTL dump: Flags. (line 242) 37313 * /i in RTL dump: Flags. (line 294) 37314 * /j in RTL dump: Flags. (line 309) 37315 * /s in RTL dump: Flags. (line 258) 37316 * /u in RTL dump: Flags. (line 319) 37317 * /v in RTL dump: Flags. (line 351) 37318 * 0 in constraint: Simple Constraints. (line 120) 37319 * < in constraint: Simple Constraints. (line 48) 37320 * = in constraint: Modifiers. (line 8) 37321 * > in constraint: Simple Constraints. (line 52) 37322 * ? in constraint: Multi-Alternative. (line 41) 37323 * \: Output Template. (line 46) 37324 * __absvdi2: Integer library routines. 37325 (line 107) 37326 * __absvsi2: Integer library routines. 37327 (line 106) 37328 * __addda3: Fixed-point fractional library routines. 37329 (line 45) 37330 * __adddf3: Soft float library routines. 37331 (line 23) 37332 * __adddq3: Fixed-point fractional library routines. 37333 (line 33) 37334 * __addha3: Fixed-point fractional library routines. 37335 (line 43) 37336 * __addhq3: Fixed-point fractional library routines. 37337 (line 30) 37338 * __addqq3: Fixed-point fractional library routines. 37339 (line 29) 37340 * __addsa3: Fixed-point fractional library routines. 37341 (line 44) 37342 * __addsf3: Soft float library routines. 37343 (line 22) 37344 * __addsq3: Fixed-point fractional library routines. 37345 (line 31) 37346 * __addta3: Fixed-point fractional library routines. 37347 (line 47) 37348 * __addtf3: Soft float library routines. 37349 (line 25) 37350 * __adduda3: Fixed-point fractional library routines. 37351 (line 53) 37352 * __addudq3: Fixed-point fractional library routines. 37353 (line 41) 37354 * __adduha3: Fixed-point fractional library routines. 37355 (line 49) 37356 * __adduhq3: Fixed-point fractional library routines. 37357 (line 37) 37358 * __adduqq3: Fixed-point fractional library routines. 37359 (line 35) 37360 * __addusa3: Fixed-point fractional library routines. 37361 (line 51) 37362 * __addusq3: Fixed-point fractional library routines. 37363 (line 39) 37364 * __adduta3: Fixed-point fractional library routines. 37365 (line 55) 37366 * __addvdi3: Integer library routines. 37367 (line 111) 37368 * __addvsi3: Integer library routines. 37369 (line 110) 37370 * __addxf3: Soft float library routines. 37371 (line 27) 37372 * __ashlda3: Fixed-point fractional library routines. 37373 (line 351) 37374 * __ashldi3: Integer library routines. 37375 (line 14) 37376 * __ashldq3: Fixed-point fractional library routines. 37377 (line 340) 37378 * __ashlha3: Fixed-point fractional library routines. 37379 (line 349) 37380 * __ashlhq3: Fixed-point fractional library routines. 37381 (line 337) 37382 * __ashlqq3: Fixed-point fractional library routines. 37383 (line 336) 37384 * __ashlsa3: Fixed-point fractional library routines. 37385 (line 350) 37386 * __ashlsi3: Integer library routines. 37387 (line 13) 37388 * __ashlsq3: Fixed-point fractional library routines. 37389 (line 338) 37390 * __ashlta3: Fixed-point fractional library routines. 37391 (line 353) 37392 * __ashlti3: Integer library routines. 37393 (line 15) 37394 * __ashluda3: Fixed-point fractional library routines. 37395 (line 359) 37396 * __ashludq3: Fixed-point fractional library routines. 37397 (line 348) 37398 * __ashluha3: Fixed-point fractional library routines. 37399 (line 355) 37400 * __ashluhq3: Fixed-point fractional library routines. 37401 (line 344) 37402 * __ashluqq3: Fixed-point fractional library routines. 37403 (line 342) 37404 * __ashlusa3: Fixed-point fractional library routines. 37405 (line 357) 37406 * __ashlusq3: Fixed-point fractional library routines. 37407 (line 346) 37408 * __ashluta3: Fixed-point fractional library routines. 37409 (line 361) 37410 * __ashrda3: Fixed-point fractional library routines. 37411 (line 371) 37412 * __ashrdi3: Integer library routines. 37413 (line 19) 37414 * __ashrdq3: Fixed-point fractional library routines. 37415 (line 368) 37416 * __ashrha3: Fixed-point fractional library routines. 37417 (line 369) 37418 * __ashrhq3: Fixed-point fractional library routines. 37419 (line 365) 37420 * __ashrqq3: Fixed-point fractional library routines. 37421 (line 364) 37422 * __ashrsa3: Fixed-point fractional library routines. 37423 (line 370) 37424 * __ashrsi3: Integer library routines. 37425 (line 18) 37426 * __ashrsq3: Fixed-point fractional library routines. 37427 (line 366) 37428 * __ashrta3: Fixed-point fractional library routines. 37429 (line 373) 37430 * __ashrti3: Integer library routines. 37431 (line 20) 37432 * __bid_adddd3: Decimal float library routines. 37433 (line 25) 37434 * __bid_addsd3: Decimal float library routines. 37435 (line 21) 37436 * __bid_addtd3: Decimal float library routines. 37437 (line 29) 37438 * __bid_divdd3: Decimal float library routines. 37439 (line 68) 37440 * __bid_divsd3: Decimal float library routines. 37441 (line 64) 37442 * __bid_divtd3: Decimal float library routines. 37443 (line 72) 37444 * __bid_eqdd2: Decimal float library routines. 37445 (line 259) 37446 * __bid_eqsd2: Decimal float library routines. 37447 (line 257) 37448 * __bid_eqtd2: Decimal float library routines. 37449 (line 261) 37450 * __bid_extendddtd2: Decimal float library routines. 37451 (line 92) 37452 * __bid_extendddtf: Decimal float library routines. 37453 (line 140) 37454 * __bid_extendddxf: Decimal float library routines. 37455 (line 134) 37456 * __bid_extenddfdd: Decimal float library routines. 37457 (line 147) 37458 * __bid_extenddftd: Decimal float library routines. 37459 (line 107) 37460 * __bid_extendsddd2: Decimal float library routines. 37461 (line 88) 37462 * __bid_extendsddf: Decimal float library routines. 37463 (line 128) 37464 * __bid_extendsdtd2: Decimal float library routines. 37465 (line 90) 37466 * __bid_extendsdtf: Decimal float library routines. 37467 (line 138) 37468 * __bid_extendsdxf: Decimal float library routines. 37469 (line 132) 37470 * __bid_extendsfdd: Decimal float library routines. 37471 (line 103) 37472 * __bid_extendsfsd: Decimal float library routines. 37473 (line 145) 37474 * __bid_extendsftd: Decimal float library routines. 37475 (line 105) 37476 * __bid_extendtftd: Decimal float library routines. 37477 (line 149) 37478 * __bid_extendxftd: Decimal float library routines. 37479 (line 109) 37480 * __bid_fixdddi: Decimal float library routines. 37481 (line 170) 37482 * __bid_fixddsi: Decimal float library routines. 37483 (line 162) 37484 * __bid_fixsddi: Decimal float library routines. 37485 (line 168) 37486 * __bid_fixsdsi: Decimal float library routines. 37487 (line 160) 37488 * __bid_fixtddi: Decimal float library routines. 37489 (line 172) 37490 * __bid_fixtdsi: Decimal float library routines. 37491 (line 164) 37492 * __bid_fixunsdddi: Decimal float library routines. 37493 (line 187) 37494 * __bid_fixunsddsi: Decimal float library routines. 37495 (line 178) 37496 * __bid_fixunssddi: Decimal float library routines. 37497 (line 185) 37498 * __bid_fixunssdsi: Decimal float library routines. 37499 (line 176) 37500 * __bid_fixunstddi: Decimal float library routines. 37501 (line 189) 37502 * __bid_fixunstdsi: Decimal float library routines. 37503 (line 180) 37504 * __bid_floatdidd: Decimal float library routines. 37505 (line 205) 37506 * __bid_floatdisd: Decimal float library routines. 37507 (line 203) 37508 * __bid_floatditd: Decimal float library routines. 37509 (line 207) 37510 * __bid_floatsidd: Decimal float library routines. 37511 (line 196) 37512 * __bid_floatsisd: Decimal float library routines. 37513 (line 194) 37514 * __bid_floatsitd: Decimal float library routines. 37515 (line 198) 37516 * __bid_floatunsdidd: Decimal float library routines. 37517 (line 223) 37518 * __bid_floatunsdisd: Decimal float library routines. 37519 (line 221) 37520 * __bid_floatunsditd: Decimal float library routines. 37521 (line 225) 37522 * __bid_floatunssidd: Decimal float library routines. 37523 (line 214) 37524 * __bid_floatunssisd: Decimal float library routines. 37525 (line 212) 37526 * __bid_floatunssitd: Decimal float library routines. 37527 (line 216) 37528 * __bid_gedd2: Decimal float library routines. 37529 (line 277) 37530 * __bid_gesd2: Decimal float library routines. 37531 (line 275) 37532 * __bid_getd2: Decimal float library routines. 37533 (line 279) 37534 * __bid_gtdd2: Decimal float library routines. 37535 (line 304) 37536 * __bid_gtsd2: Decimal float library routines. 37537 (line 302) 37538 * __bid_gttd2: Decimal float library routines. 37539 (line 306) 37540 * __bid_ledd2: Decimal float library routines. 37541 (line 295) 37542 * __bid_lesd2: Decimal float library routines. 37543 (line 293) 37544 * __bid_letd2: Decimal float library routines. 37545 (line 297) 37546 * __bid_ltdd2: Decimal float library routines. 37547 (line 286) 37548 * __bid_ltsd2: Decimal float library routines. 37549 (line 284) 37550 * __bid_lttd2: Decimal float library routines. 37551 (line 288) 37552 * __bid_muldd3: Decimal float library routines. 37553 (line 54) 37554 * __bid_mulsd3: Decimal float library routines. 37555 (line 50) 37556 * __bid_multd3: Decimal float library routines. 37557 (line 58) 37558 * __bid_nedd2: Decimal float library routines. 37559 (line 268) 37560 * __bid_negdd2: Decimal float library routines. 37561 (line 78) 37562 * __bid_negsd2: Decimal float library routines. 37563 (line 76) 37564 * __bid_negtd2: Decimal float library routines. 37565 (line 80) 37566 * __bid_nesd2: Decimal float library routines. 37567 (line 266) 37568 * __bid_netd2: Decimal float library routines. 37569 (line 270) 37570 * __bid_subdd3: Decimal float library routines. 37571 (line 39) 37572 * __bid_subsd3: Decimal float library routines. 37573 (line 35) 37574 * __bid_subtd3: Decimal float library routines. 37575 (line 43) 37576 * __bid_truncdddf: Decimal float library routines. 37577 (line 153) 37578 * __bid_truncddsd2: Decimal float library routines. 37579 (line 94) 37580 * __bid_truncddsf: Decimal float library routines. 37581 (line 124) 37582 * __bid_truncdfsd: Decimal float library routines. 37583 (line 111) 37584 * __bid_truncsdsf: Decimal float library routines. 37585 (line 151) 37586 * __bid_trunctddd2: Decimal float library routines. 37587 (line 98) 37588 * __bid_trunctddf: Decimal float library routines. 37589 (line 130) 37590 * __bid_trunctdsd2: Decimal float library routines. 37591 (line 96) 37592 * __bid_trunctdsf: Decimal float library routines. 37593 (line 126) 37594 * __bid_trunctdtf: Decimal float library routines. 37595 (line 155) 37596 * __bid_trunctdxf: Decimal float library routines. 37597 (line 136) 37598 * __bid_trunctfdd: Decimal float library routines. 37599 (line 119) 37600 * __bid_trunctfsd: Decimal float library routines. 37601 (line 115) 37602 * __bid_truncxfdd: Decimal float library routines. 37603 (line 117) 37604 * __bid_truncxfsd: Decimal float library routines. 37605 (line 113) 37606 * __bid_unorddd2: Decimal float library routines. 37607 (line 235) 37608 * __bid_unordsd2: Decimal float library routines. 37609 (line 233) 37610 * __bid_unordtd2: Decimal float library routines. 37611 (line 237) 37612 * __bswapdi2: Integer library routines. 37613 (line 162) 37614 * __bswapsi2: Integer library routines. 37615 (line 161) 37616 * __builtin_args_info: Varargs. (line 42) 37617 * __builtin_classify_type: Varargs. (line 76) 37618 * __builtin_next_arg: Varargs. (line 66) 37619 * __builtin_saveregs: Varargs. (line 24) 37620 * __clear_cache: Miscellaneous routines. 37621 (line 10) 37622 * __clzdi2: Integer library routines. 37623 (line 131) 37624 * __clzsi2: Integer library routines. 37625 (line 130) 37626 * __clzti2: Integer library routines. 37627 (line 132) 37628 * __cmpda2: Fixed-point fractional library routines. 37629 (line 451) 37630 * __cmpdf2: Soft float library routines. 37631 (line 164) 37632 * __cmpdi2: Integer library routines. 37633 (line 87) 37634 * __cmpdq2: Fixed-point fractional library routines. 37635 (line 441) 37636 * __cmpha2: Fixed-point fractional library routines. 37637 (line 449) 37638 * __cmphq2: Fixed-point fractional library routines. 37639 (line 438) 37640 * __cmpqq2: Fixed-point fractional library routines. 37641 (line 437) 37642 * __cmpsa2: Fixed-point fractional library routines. 37643 (line 450) 37644 * __cmpsf2: Soft float library routines. 37645 (line 163) 37646 * __cmpsq2: Fixed-point fractional library routines. 37647 (line 439) 37648 * __cmpta2: Fixed-point fractional library routines. 37649 (line 453) 37650 * __cmptf2: Soft float library routines. 37651 (line 165) 37652 * __cmpti2: Integer library routines. 37653 (line 88) 37654 * __cmpuda2: Fixed-point fractional library routines. 37655 (line 458) 37656 * __cmpudq2: Fixed-point fractional library routines. 37657 (line 448) 37658 * __cmpuha2: Fixed-point fractional library routines. 37659 (line 455) 37660 * __cmpuhq2: Fixed-point fractional library routines. 37661 (line 444) 37662 * __cmpuqq2: Fixed-point fractional library routines. 37663 (line 443) 37664 * __cmpusa2: Fixed-point fractional library routines. 37665 (line 456) 37666 * __cmpusq2: Fixed-point fractional library routines. 37667 (line 446) 37668 * __cmputa2: Fixed-point fractional library routines. 37669 (line 460) 37670 * __CTOR_LIST__: Initialization. (line 25) 37671 * __ctzdi2: Integer library routines. 37672 (line 138) 37673 * __ctzsi2: Integer library routines. 37674 (line 137) 37675 * __ctzti2: Integer library routines. 37676 (line 139) 37677 * __divda3: Fixed-point fractional library routines. 37678 (line 227) 37679 * __divdc3: Soft float library routines. 37680 (line 252) 37681 * __divdf3: Soft float library routines. 37682 (line 48) 37683 * __divdi3: Integer library routines. 37684 (line 25) 37685 * __divdq3: Fixed-point fractional library routines. 37686 (line 223) 37687 * __divha3: Fixed-point fractional library routines. 37688 (line 225) 37689 * __divhq3: Fixed-point fractional library routines. 37690 (line 220) 37691 * __divqq3: Fixed-point fractional library routines. 37692 (line 219) 37693 * __divsa3: Fixed-point fractional library routines. 37694 (line 226) 37695 * __divsc3: Soft float library routines. 37696 (line 250) 37697 * __divsf3: Soft float library routines. 37698 (line 47) 37699 * __divsi3: Integer library routines. 37700 (line 24) 37701 * __divsq3: Fixed-point fractional library routines. 37702 (line 221) 37703 * __divta3: Fixed-point fractional library routines. 37704 (line 229) 37705 * __divtc3: Soft float library routines. 37706 (line 254) 37707 * __divtf3: Soft float library routines. 37708 (line 50) 37709 * __divti3: Integer library routines. 37710 (line 26) 37711 * __divxc3: Soft float library routines. 37712 (line 256) 37713 * __divxf3: Soft float library routines. 37714 (line 52) 37715 * __dpd_adddd3: Decimal float library routines. 37716 (line 23) 37717 * __dpd_addsd3: Decimal float library routines. 37718 (line 19) 37719 * __dpd_addtd3: Decimal float library routines. 37720 (line 27) 37721 * __dpd_divdd3: Decimal float library routines. 37722 (line 66) 37723 * __dpd_divsd3: Decimal float library routines. 37724 (line 62) 37725 * __dpd_divtd3: Decimal float library routines. 37726 (line 70) 37727 * __dpd_eqdd2: Decimal float library routines. 37728 (line 258) 37729 * __dpd_eqsd2: Decimal float library routines. 37730 (line 256) 37731 * __dpd_eqtd2: Decimal float library routines. 37732 (line 260) 37733 * __dpd_extendddtd2: Decimal float library routines. 37734 (line 91) 37735 * __dpd_extendddtf: Decimal float library routines. 37736 (line 139) 37737 * __dpd_extendddxf: Decimal float library routines. 37738 (line 133) 37739 * __dpd_extenddfdd: Decimal float library routines. 37740 (line 146) 37741 * __dpd_extenddftd: Decimal float library routines. 37742 (line 106) 37743 * __dpd_extendsddd2: Decimal float library routines. 37744 (line 87) 37745 * __dpd_extendsddf: Decimal float library routines. 37746 (line 127) 37747 * __dpd_extendsdtd2: Decimal float library routines. 37748 (line 89) 37749 * __dpd_extendsdtf: Decimal float library routines. 37750 (line 137) 37751 * __dpd_extendsdxf: Decimal float library routines. 37752 (line 131) 37753 * __dpd_extendsfdd: Decimal float library routines. 37754 (line 102) 37755 * __dpd_extendsfsd: Decimal float library routines. 37756 (line 144) 37757 * __dpd_extendsftd: Decimal float library routines. 37758 (line 104) 37759 * __dpd_extendtftd: Decimal float library routines. 37760 (line 148) 37761 * __dpd_extendxftd: Decimal float library routines. 37762 (line 108) 37763 * __dpd_fixdddi: Decimal float library routines. 37764 (line 169) 37765 * __dpd_fixddsi: Decimal float library routines. 37766 (line 161) 37767 * __dpd_fixsddi: Decimal float library routines. 37768 (line 167) 37769 * __dpd_fixsdsi: Decimal float library routines. 37770 (line 159) 37771 * __dpd_fixtddi: Decimal float library routines. 37772 (line 171) 37773 * __dpd_fixtdsi: Decimal float library routines. 37774 (line 163) 37775 * __dpd_fixunsdddi: Decimal float library routines. 37776 (line 186) 37777 * __dpd_fixunsddsi: Decimal float library routines. 37778 (line 177) 37779 * __dpd_fixunssddi: Decimal float library routines. 37780 (line 184) 37781 * __dpd_fixunssdsi: Decimal float library routines. 37782 (line 175) 37783 * __dpd_fixunstddi: Decimal float library routines. 37784 (line 188) 37785 * __dpd_fixunstdsi: Decimal float library routines. 37786 (line 179) 37787 * __dpd_floatdidd: Decimal float library routines. 37788 (line 204) 37789 * __dpd_floatdisd: Decimal float library routines. 37790 (line 202) 37791 * __dpd_floatditd: Decimal float library routines. 37792 (line 206) 37793 * __dpd_floatsidd: Decimal float library routines. 37794 (line 195) 37795 * __dpd_floatsisd: Decimal float library routines. 37796 (line 193) 37797 * __dpd_floatsitd: Decimal float library routines. 37798 (line 197) 37799 * __dpd_floatunsdidd: Decimal float library routines. 37800 (line 222) 37801 * __dpd_floatunsdisd: Decimal float library routines. 37802 (line 220) 37803 * __dpd_floatunsditd: Decimal float library routines. 37804 (line 224) 37805 * __dpd_floatunssidd: Decimal float library routines. 37806 (line 213) 37807 * __dpd_floatunssisd: Decimal float library routines. 37808 (line 211) 37809 * __dpd_floatunssitd: Decimal float library routines. 37810 (line 215) 37811 * __dpd_gedd2: Decimal float library routines. 37812 (line 276) 37813 * __dpd_gesd2: Decimal float library routines. 37814 (line 274) 37815 * __dpd_getd2: Decimal float library routines. 37816 (line 278) 37817 * __dpd_gtdd2: Decimal float library routines. 37818 (line 303) 37819 * __dpd_gtsd2: Decimal float library routines. 37820 (line 301) 37821 * __dpd_gttd2: Decimal float library routines. 37822 (line 305) 37823 * __dpd_ledd2: Decimal float library routines. 37824 (line 294) 37825 * __dpd_lesd2: Decimal float library routines. 37826 (line 292) 37827 * __dpd_letd2: Decimal float library routines. 37828 (line 296) 37829 * __dpd_ltdd2: Decimal float library routines. 37830 (line 285) 37831 * __dpd_ltsd2: Decimal float library routines. 37832 (line 283) 37833 * __dpd_lttd2: Decimal float library routines. 37834 (line 287) 37835 * __dpd_muldd3: Decimal float library routines. 37836 (line 52) 37837 * __dpd_mulsd3: Decimal float library routines. 37838 (line 48) 37839 * __dpd_multd3: Decimal float library routines. 37840 (line 56) 37841 * __dpd_nedd2: Decimal float library routines. 37842 (line 267) 37843 * __dpd_negdd2: Decimal float library routines. 37844 (line 77) 37845 * __dpd_negsd2: Decimal float library routines. 37846 (line 75) 37847 * __dpd_negtd2: Decimal float library routines. 37848 (line 79) 37849 * __dpd_nesd2: Decimal float library routines. 37850 (line 265) 37851 * __dpd_netd2: Decimal float library routines. 37852 (line 269) 37853 * __dpd_subdd3: Decimal float library routines. 37854 (line 37) 37855 * __dpd_subsd3: Decimal float library routines. 37856 (line 33) 37857 * __dpd_subtd3: Decimal float library routines. 37858 (line 41) 37859 * __dpd_truncdddf: Decimal float library routines. 37860 (line 152) 37861 * __dpd_truncddsd2: Decimal float library routines. 37862 (line 93) 37863 * __dpd_truncddsf: Decimal float library routines. 37864 (line 123) 37865 * __dpd_truncdfsd: Decimal float library routines. 37866 (line 110) 37867 * __dpd_truncsdsf: Decimal float library routines. 37868 (line 150) 37869 * __dpd_trunctddd2: Decimal float library routines. 37870 (line 97) 37871 * __dpd_trunctddf: Decimal float library routines. 37872 (line 129) 37873 * __dpd_trunctdsd2: Decimal float library routines. 37874 (line 95) 37875 * __dpd_trunctdsf: Decimal float library routines. 37876 (line 125) 37877 * __dpd_trunctdtf: Decimal float library routines. 37878 (line 154) 37879 * __dpd_trunctdxf: Decimal float library routines. 37880 (line 135) 37881 * __dpd_trunctfdd: Decimal float library routines. 37882 (line 118) 37883 * __dpd_trunctfsd: Decimal float library routines. 37884 (line 114) 37885 * __dpd_truncxfdd: Decimal float library routines. 37886 (line 116) 37887 * __dpd_truncxfsd: Decimal float library routines. 37888 (line 112) 37889 * __dpd_unorddd2: Decimal float library routines. 37890 (line 234) 37891 * __dpd_unordsd2: Decimal float library routines. 37892 (line 232) 37893 * __dpd_unordtd2: Decimal float library routines. 37894 (line 236) 37895 * __DTOR_LIST__: Initialization. (line 25) 37896 * __eqdf2: Soft float library routines. 37897 (line 194) 37898 * __eqsf2: Soft float library routines. 37899 (line 193) 37900 * __eqtf2: Soft float library routines. 37901 (line 195) 37902 * __extenddftf2: Soft float library routines. 37903 (line 68) 37904 * __extenddfxf2: Soft float library routines. 37905 (line 69) 37906 * __extendsfdf2: Soft float library routines. 37907 (line 65) 37908 * __extendsftf2: Soft float library routines. 37909 (line 66) 37910 * __extendsfxf2: Soft float library routines. 37911 (line 67) 37912 * __ffsdi2: Integer library routines. 37913 (line 144) 37914 * __ffsti2: Integer library routines. 37915 (line 145) 37916 * __fixdfdi: Soft float library routines. 37917 (line 88) 37918 * __fixdfsi: Soft float library routines. 37919 (line 81) 37920 * __fixdfti: Soft float library routines. 37921 (line 94) 37922 * __fixsfdi: Soft float library routines. 37923 (line 87) 37924 * __fixsfsi: Soft float library routines. 37925 (line 80) 37926 * __fixsfti: Soft float library routines. 37927 (line 93) 37928 * __fixtfdi: Soft float library routines. 37929 (line 89) 37930 * __fixtfsi: Soft float library routines. 37931 (line 82) 37932 * __fixtfti: Soft float library routines. 37933 (line 95) 37934 * __fixunsdfdi: Soft float library routines. 37935 (line 108) 37936 * __fixunsdfsi: Soft float library routines. 37937 (line 101) 37938 * __fixunsdfti: Soft float library routines. 37939 (line 115) 37940 * __fixunssfdi: Soft float library routines. 37941 (line 107) 37942 * __fixunssfsi: Soft float library routines. 37943 (line 100) 37944 * __fixunssfti: Soft float library routines. 37945 (line 114) 37946 * __fixunstfdi: Soft float library routines. 37947 (line 109) 37948 * __fixunstfsi: Soft float library routines. 37949 (line 102) 37950 * __fixunstfti: Soft float library routines. 37951 (line 116) 37952 * __fixunsxfdi: Soft float library routines. 37953 (line 110) 37954 * __fixunsxfsi: Soft float library routines. 37955 (line 103) 37956 * __fixunsxfti: Soft float library routines. 37957 (line 117) 37958 * __fixxfdi: Soft float library routines. 37959 (line 90) 37960 * __fixxfsi: Soft float library routines. 37961 (line 83) 37962 * __fixxfti: Soft float library routines. 37963 (line 96) 37964 * __floatdidf: Soft float library routines. 37965 (line 128) 37966 * __floatdisf: Soft float library routines. 37967 (line 127) 37968 * __floatditf: Soft float library routines. 37969 (line 129) 37970 * __floatdixf: Soft float library routines. 37971 (line 130) 37972 * __floatsidf: Soft float library routines. 37973 (line 122) 37974 * __floatsisf: Soft float library routines. 37975 (line 121) 37976 * __floatsitf: Soft float library routines. 37977 (line 123) 37978 * __floatsixf: Soft float library routines. 37979 (line 124) 37980 * __floattidf: Soft float library routines. 37981 (line 134) 37982 * __floattisf: Soft float library routines. 37983 (line 133) 37984 * __floattitf: Soft float library routines. 37985 (line 135) 37986 * __floattixf: Soft float library routines. 37987 (line 136) 37988 * __floatundidf: Soft float library routines. 37989 (line 146) 37990 * __floatundisf: Soft float library routines. 37991 (line 145) 37992 * __floatunditf: Soft float library routines. 37993 (line 147) 37994 * __floatundixf: Soft float library routines. 37995 (line 148) 37996 * __floatunsidf: Soft float library routines. 37997 (line 140) 37998 * __floatunsisf: Soft float library routines. 37999 (line 139) 38000 * __floatunsitf: Soft float library routines. 38001 (line 141) 38002 * __floatunsixf: Soft float library routines. 38003 (line 142) 38004 * __floatuntidf: Soft float library routines. 38005 (line 152) 38006 * __floatuntisf: Soft float library routines. 38007 (line 151) 38008 * __floatuntitf: Soft float library routines. 38009 (line 153) 38010 * __floatuntixf: Soft float library routines. 38011 (line 154) 38012 * __fractdadf: Fixed-point fractional library routines. 38013 (line 636) 38014 * __fractdadi: Fixed-point fractional library routines. 38015 (line 633) 38016 * __fractdadq: Fixed-point fractional library routines. 38017 (line 616) 38018 * __fractdaha2: Fixed-point fractional library routines. 38019 (line 617) 38020 * __fractdahi: Fixed-point fractional library routines. 38021 (line 631) 38022 * __fractdahq: Fixed-point fractional library routines. 38023 (line 614) 38024 * __fractdaqi: Fixed-point fractional library routines. 38025 (line 630) 38026 * __fractdaqq: Fixed-point fractional library routines. 38027 (line 613) 38028 * __fractdasa2: Fixed-point fractional library routines. 38029 (line 618) 38030 * __fractdasf: Fixed-point fractional library routines. 38031 (line 635) 38032 * __fractdasi: Fixed-point fractional library routines. 38033 (line 632) 38034 * __fractdasq: Fixed-point fractional library routines. 38035 (line 615) 38036 * __fractdata2: Fixed-point fractional library routines. 38037 (line 619) 38038 * __fractdati: Fixed-point fractional library routines. 38039 (line 634) 38040 * __fractdauda: Fixed-point fractional library routines. 38041 (line 627) 38042 * __fractdaudq: Fixed-point fractional library routines. 38043 (line 624) 38044 * __fractdauha: Fixed-point fractional library routines. 38045 (line 625) 38046 * __fractdauhq: Fixed-point fractional library routines. 38047 (line 621) 38048 * __fractdauqq: Fixed-point fractional library routines. 38049 (line 620) 38050 * __fractdausa: Fixed-point fractional library routines. 38051 (line 626) 38052 * __fractdausq: Fixed-point fractional library routines. 38053 (line 622) 38054 * __fractdauta: Fixed-point fractional library routines. 38055 (line 629) 38056 * __fractdfda: Fixed-point fractional library routines. 38057 (line 1025) 38058 * __fractdfdq: Fixed-point fractional library routines. 38059 (line 1022) 38060 * __fractdfha: Fixed-point fractional library routines. 38061 (line 1023) 38062 * __fractdfhq: Fixed-point fractional library routines. 38063 (line 1020) 38064 * __fractdfqq: Fixed-point fractional library routines. 38065 (line 1019) 38066 * __fractdfsa: Fixed-point fractional library routines. 38067 (line 1024) 38068 * __fractdfsq: Fixed-point fractional library routines. 38069 (line 1021) 38070 * __fractdfta: Fixed-point fractional library routines. 38071 (line 1026) 38072 * __fractdfuda: Fixed-point fractional library routines. 38073 (line 1033) 38074 * __fractdfudq: Fixed-point fractional library routines. 38075 (line 1030) 38076 * __fractdfuha: Fixed-point fractional library routines. 38077 (line 1031) 38078 * __fractdfuhq: Fixed-point fractional library routines. 38079 (line 1028) 38080 * __fractdfuqq: Fixed-point fractional library routines. 38081 (line 1027) 38082 * __fractdfusa: Fixed-point fractional library routines. 38083 (line 1032) 38084 * __fractdfusq: Fixed-point fractional library routines. 38085 (line 1029) 38086 * __fractdfuta: Fixed-point fractional library routines. 38087 (line 1034) 38088 * __fractdida: Fixed-point fractional library routines. 38089 (line 975) 38090 * __fractdidq: Fixed-point fractional library routines. 38091 (line 972) 38092 * __fractdiha: Fixed-point fractional library routines. 38093 (line 973) 38094 * __fractdihq: Fixed-point fractional library routines. 38095 (line 970) 38096 * __fractdiqq: Fixed-point fractional library routines. 38097 (line 969) 38098 * __fractdisa: Fixed-point fractional library routines. 38099 (line 974) 38100 * __fractdisq: Fixed-point fractional library routines. 38101 (line 971) 38102 * __fractdita: Fixed-point fractional library routines. 38103 (line 976) 38104 * __fractdiuda: Fixed-point fractional library routines. 38105 (line 983) 38106 * __fractdiudq: Fixed-point fractional library routines. 38107 (line 980) 38108 * __fractdiuha: Fixed-point fractional library routines. 38109 (line 981) 38110 * __fractdiuhq: Fixed-point fractional library routines. 38111 (line 978) 38112 * __fractdiuqq: Fixed-point fractional library routines. 38113 (line 977) 38114 * __fractdiusa: Fixed-point fractional library routines. 38115 (line 982) 38116 * __fractdiusq: Fixed-point fractional library routines. 38117 (line 979) 38118 * __fractdiuta: Fixed-point fractional library routines. 38119 (line 984) 38120 * __fractdqda: Fixed-point fractional library routines. 38121 (line 544) 38122 * __fractdqdf: Fixed-point fractional library routines. 38123 (line 566) 38124 * __fractdqdi: Fixed-point fractional library routines. 38125 (line 563) 38126 * __fractdqha: Fixed-point fractional library routines. 38127 (line 542) 38128 * __fractdqhi: Fixed-point fractional library routines. 38129 (line 561) 38130 * __fractdqhq2: Fixed-point fractional library routines. 38131 (line 540) 38132 * __fractdqqi: Fixed-point fractional library routines. 38133 (line 560) 38134 * __fractdqqq2: Fixed-point fractional library routines. 38135 (line 539) 38136 * __fractdqsa: Fixed-point fractional library routines. 38137 (line 543) 38138 * __fractdqsf: Fixed-point fractional library routines. 38139 (line 565) 38140 * __fractdqsi: Fixed-point fractional library routines. 38141 (line 562) 38142 * __fractdqsq2: Fixed-point fractional library routines. 38143 (line 541) 38144 * __fractdqta: Fixed-point fractional library routines. 38145 (line 545) 38146 * __fractdqti: Fixed-point fractional library routines. 38147 (line 564) 38148 * __fractdquda: Fixed-point fractional library routines. 38149 (line 557) 38150 * __fractdqudq: Fixed-point fractional library routines. 38151 (line 552) 38152 * __fractdquha: Fixed-point fractional library routines. 38153 (line 554) 38154 * __fractdquhq: Fixed-point fractional library routines. 38155 (line 548) 38156 * __fractdquqq: Fixed-point fractional library routines. 38157 (line 547) 38158 * __fractdqusa: Fixed-point fractional library routines. 38159 (line 555) 38160 * __fractdqusq: Fixed-point fractional library routines. 38161 (line 550) 38162 * __fractdquta: Fixed-point fractional library routines. 38163 (line 559) 38164 * __fracthada2: Fixed-point fractional library routines. 38165 (line 572) 38166 * __fracthadf: Fixed-point fractional library routines. 38167 (line 590) 38168 * __fracthadi: Fixed-point fractional library routines. 38169 (line 587) 38170 * __fracthadq: Fixed-point fractional library routines. 38171 (line 570) 38172 * __fracthahi: Fixed-point fractional library routines. 38173 (line 585) 38174 * __fracthahq: Fixed-point fractional library routines. 38175 (line 568) 38176 * __fracthaqi: Fixed-point fractional library routines. 38177 (line 584) 38178 * __fracthaqq: Fixed-point fractional library routines. 38179 (line 567) 38180 * __fracthasa2: Fixed-point fractional library routines. 38181 (line 571) 38182 * __fracthasf: Fixed-point fractional library routines. 38183 (line 589) 38184 * __fracthasi: Fixed-point fractional library routines. 38185 (line 586) 38186 * __fracthasq: Fixed-point fractional library routines. 38187 (line 569) 38188 * __fracthata2: Fixed-point fractional library routines. 38189 (line 573) 38190 * __fracthati: Fixed-point fractional library routines. 38191 (line 588) 38192 * __fracthauda: Fixed-point fractional library routines. 38193 (line 581) 38194 * __fracthaudq: Fixed-point fractional library routines. 38195 (line 578) 38196 * __fracthauha: Fixed-point fractional library routines. 38197 (line 579) 38198 * __fracthauhq: Fixed-point fractional library routines. 38199 (line 575) 38200 * __fracthauqq: Fixed-point fractional library routines. 38201 (line 574) 38202 * __fracthausa: Fixed-point fractional library routines. 38203 (line 580) 38204 * __fracthausq: Fixed-point fractional library routines. 38205 (line 576) 38206 * __fracthauta: Fixed-point fractional library routines. 38207 (line 583) 38208 * __fracthida: Fixed-point fractional library routines. 38209 (line 943) 38210 * __fracthidq: Fixed-point fractional library routines. 38211 (line 940) 38212 * __fracthiha: Fixed-point fractional library routines. 38213 (line 941) 38214 * __fracthihq: Fixed-point fractional library routines. 38215 (line 938) 38216 * __fracthiqq: Fixed-point fractional library routines. 38217 (line 937) 38218 * __fracthisa: Fixed-point fractional library routines. 38219 (line 942) 38220 * __fracthisq: Fixed-point fractional library routines. 38221 (line 939) 38222 * __fracthita: Fixed-point fractional library routines. 38223 (line 944) 38224 * __fracthiuda: Fixed-point fractional library routines. 38225 (line 951) 38226 * __fracthiudq: Fixed-point fractional library routines. 38227 (line 948) 38228 * __fracthiuha: Fixed-point fractional library routines. 38229 (line 949) 38230 * __fracthiuhq: Fixed-point fractional library routines. 38231 (line 946) 38232 * __fracthiuqq: Fixed-point fractional library routines. 38233 (line 945) 38234 * __fracthiusa: Fixed-point fractional library routines. 38235 (line 950) 38236 * __fracthiusq: Fixed-point fractional library routines. 38237 (line 947) 38238 * __fracthiuta: Fixed-point fractional library routines. 38239 (line 952) 38240 * __fracthqda: Fixed-point fractional library routines. 38241 (line 498) 38242 * __fracthqdf: Fixed-point fractional library routines. 38243 (line 514) 38244 * __fracthqdi: Fixed-point fractional library routines. 38245 (line 511) 38246 * __fracthqdq2: Fixed-point fractional library routines. 38247 (line 495) 38248 * __fracthqha: Fixed-point fractional library routines. 38249 (line 496) 38250 * __fracthqhi: Fixed-point fractional library routines. 38251 (line 509) 38252 * __fracthqqi: Fixed-point fractional library routines. 38253 (line 508) 38254 * __fracthqqq2: Fixed-point fractional library routines. 38255 (line 493) 38256 * __fracthqsa: Fixed-point fractional library routines. 38257 (line 497) 38258 * __fracthqsf: Fixed-point fractional library routines. 38259 (line 513) 38260 * __fracthqsi: Fixed-point fractional library routines. 38261 (line 510) 38262 * __fracthqsq2: Fixed-point fractional library routines. 38263 (line 494) 38264 * __fracthqta: Fixed-point fractional library routines. 38265 (line 499) 38266 * __fracthqti: Fixed-point fractional library routines. 38267 (line 512) 38268 * __fracthquda: Fixed-point fractional library routines. 38269 (line 506) 38270 * __fracthqudq: Fixed-point fractional library routines. 38271 (line 503) 38272 * __fracthquha: Fixed-point fractional library routines. 38273 (line 504) 38274 * __fracthquhq: Fixed-point fractional library routines. 38275 (line 501) 38276 * __fracthquqq: Fixed-point fractional library routines. 38277 (line 500) 38278 * __fracthqusa: Fixed-point fractional library routines. 38279 (line 505) 38280 * __fracthqusq: Fixed-point fractional library routines. 38281 (line 502) 38282 * __fracthquta: Fixed-point fractional library routines. 38283 (line 507) 38284 * __fractqida: Fixed-point fractional library routines. 38285 (line 925) 38286 * __fractqidq: Fixed-point fractional library routines. 38287 (line 922) 38288 * __fractqiha: Fixed-point fractional library routines. 38289 (line 923) 38290 * __fractqihq: Fixed-point fractional library routines. 38291 (line 920) 38292 * __fractqiqq: Fixed-point fractional library routines. 38293 (line 919) 38294 * __fractqisa: Fixed-point fractional library routines. 38295 (line 924) 38296 * __fractqisq: Fixed-point fractional library routines. 38297 (line 921) 38298 * __fractqita: Fixed-point fractional library routines. 38299 (line 926) 38300 * __fractqiuda: Fixed-point fractional library routines. 38301 (line 934) 38302 * __fractqiudq: Fixed-point fractional library routines. 38303 (line 931) 38304 * __fractqiuha: Fixed-point fractional library routines. 38305 (line 932) 38306 * __fractqiuhq: Fixed-point fractional library routines. 38307 (line 928) 38308 * __fractqiuqq: Fixed-point fractional library routines. 38309 (line 927) 38310 * __fractqiusa: Fixed-point fractional library routines. 38311 (line 933) 38312 * __fractqiusq: Fixed-point fractional library routines. 38313 (line 929) 38314 * __fractqiuta: Fixed-point fractional library routines. 38315 (line 936) 38316 * __fractqqda: Fixed-point fractional library routines. 38317 (line 474) 38318 * __fractqqdf: Fixed-point fractional library routines. 38319 (line 492) 38320 * __fractqqdi: Fixed-point fractional library routines. 38321 (line 489) 38322 * __fractqqdq2: Fixed-point fractional library routines. 38323 (line 471) 38324 * __fractqqha: Fixed-point fractional library routines. 38325 (line 472) 38326 * __fractqqhi: Fixed-point fractional library routines. 38327 (line 487) 38328 * __fractqqhq2: Fixed-point fractional library routines. 38329 (line 469) 38330 * __fractqqqi: Fixed-point fractional library routines. 38331 (line 486) 38332 * __fractqqsa: Fixed-point fractional library routines. 38333 (line 473) 38334 * __fractqqsf: Fixed-point fractional library routines. 38335 (line 491) 38336 * __fractqqsi: Fixed-point fractional library routines. 38337 (line 488) 38338 * __fractqqsq2: Fixed-point fractional library routines. 38339 (line 470) 38340 * __fractqqta: Fixed-point fractional library routines. 38341 (line 475) 38342 * __fractqqti: Fixed-point fractional library routines. 38343 (line 490) 38344 * __fractqquda: Fixed-point fractional library routines. 38345 (line 483) 38346 * __fractqqudq: Fixed-point fractional library routines. 38347 (line 480) 38348 * __fractqquha: Fixed-point fractional library routines. 38349 (line 481) 38350 * __fractqquhq: Fixed-point fractional library routines. 38351 (line 477) 38352 * __fractqquqq: Fixed-point fractional library routines. 38353 (line 476) 38354 * __fractqqusa: Fixed-point fractional library routines. 38355 (line 482) 38356 * __fractqqusq: Fixed-point fractional library routines. 38357 (line 478) 38358 * __fractqquta: Fixed-point fractional library routines. 38359 (line 485) 38360 * __fractsada2: Fixed-point fractional library routines. 38361 (line 596) 38362 * __fractsadf: Fixed-point fractional library routines. 38363 (line 612) 38364 * __fractsadi: Fixed-point fractional library routines. 38365 (line 609) 38366 * __fractsadq: Fixed-point fractional library routines. 38367 (line 594) 38368 * __fractsaha2: Fixed-point fractional library routines. 38369 (line 595) 38370 * __fractsahi: Fixed-point fractional library routines. 38371 (line 607) 38372 * __fractsahq: Fixed-point fractional library routines. 38373 (line 592) 38374 * __fractsaqi: Fixed-point fractional library routines. 38375 (line 606) 38376 * __fractsaqq: Fixed-point fractional library routines. 38377 (line 591) 38378 * __fractsasf: Fixed-point fractional library routines. 38379 (line 611) 38380 * __fractsasi: Fixed-point fractional library routines. 38381 (line 608) 38382 * __fractsasq: Fixed-point fractional library routines. 38383 (line 593) 38384 * __fractsata2: Fixed-point fractional library routines. 38385 (line 597) 38386 * __fractsati: Fixed-point fractional library routines. 38387 (line 610) 38388 * __fractsauda: Fixed-point fractional library routines. 38389 (line 604) 38390 * __fractsaudq: Fixed-point fractional library routines. 38391 (line 601) 38392 * __fractsauha: Fixed-point fractional library routines. 38393 (line 602) 38394 * __fractsauhq: Fixed-point fractional library routines. 38395 (line 599) 38396 * __fractsauqq: Fixed-point fractional library routines. 38397 (line 598) 38398 * __fractsausa: Fixed-point fractional library routines. 38399 (line 603) 38400 * __fractsausq: Fixed-point fractional library routines. 38401 (line 600) 38402 * __fractsauta: Fixed-point fractional library routines. 38403 (line 605) 38404 * __fractsfda: Fixed-point fractional library routines. 38405 (line 1009) 38406 * __fractsfdq: Fixed-point fractional library routines. 38407 (line 1006) 38408 * __fractsfha: Fixed-point fractional library routines. 38409 (line 1007) 38410 * __fractsfhq: Fixed-point fractional library routines. 38411 (line 1004) 38412 * __fractsfqq: Fixed-point fractional library routines. 38413 (line 1003) 38414 * __fractsfsa: Fixed-point fractional library routines. 38415 (line 1008) 38416 * __fractsfsq: Fixed-point fractional library routines. 38417 (line 1005) 38418 * __fractsfta: Fixed-point fractional library routines. 38419 (line 1010) 38420 * __fractsfuda: Fixed-point fractional library routines. 38421 (line 1017) 38422 * __fractsfudq: Fixed-point fractional library routines. 38423 (line 1014) 38424 * __fractsfuha: Fixed-point fractional library routines. 38425 (line 1015) 38426 * __fractsfuhq: Fixed-point fractional library routines. 38427 (line 1012) 38428 * __fractsfuqq: Fixed-point fractional library routines. 38429 (line 1011) 38430 * __fractsfusa: Fixed-point fractional library routines. 38431 (line 1016) 38432 * __fractsfusq: Fixed-point fractional library routines. 38433 (line 1013) 38434 * __fractsfuta: Fixed-point fractional library routines. 38435 (line 1018) 38436 * __fractsida: Fixed-point fractional library routines. 38437 (line 959) 38438 * __fractsidq: Fixed-point fractional library routines. 38439 (line 956) 38440 * __fractsiha: Fixed-point fractional library routines. 38441 (line 957) 38442 * __fractsihq: Fixed-point fractional library routines. 38443 (line 954) 38444 * __fractsiqq: Fixed-point fractional library routines. 38445 (line 953) 38446 * __fractsisa: Fixed-point fractional library routines. 38447 (line 958) 38448 * __fractsisq: Fixed-point fractional library routines. 38449 (line 955) 38450 * __fractsita: Fixed-point fractional library routines. 38451 (line 960) 38452 * __fractsiuda: Fixed-point fractional library routines. 38453 (line 967) 38454 * __fractsiudq: Fixed-point fractional library routines. 38455 (line 964) 38456 * __fractsiuha: Fixed-point fractional library routines. 38457 (line 965) 38458 * __fractsiuhq: Fixed-point fractional library routines. 38459 (line 962) 38460 * __fractsiuqq: Fixed-point fractional library routines. 38461 (line 961) 38462 * __fractsiusa: Fixed-point fractional library routines. 38463 (line 966) 38464 * __fractsiusq: Fixed-point fractional library routines. 38465 (line 963) 38466 * __fractsiuta: Fixed-point fractional library routines. 38467 (line 968) 38468 * __fractsqda: Fixed-point fractional library routines. 38469 (line 520) 38470 * __fractsqdf: Fixed-point fractional library routines. 38471 (line 538) 38472 * __fractsqdi: Fixed-point fractional library routines. 38473 (line 535) 38474 * __fractsqdq2: Fixed-point fractional library routines. 38475 (line 517) 38476 * __fractsqha: Fixed-point fractional library routines. 38477 (line 518) 38478 * __fractsqhi: Fixed-point fractional library routines. 38479 (line 533) 38480 * __fractsqhq2: Fixed-point fractional library routines. 38481 (line 516) 38482 * __fractsqqi: Fixed-point fractional library routines. 38483 (line 532) 38484 * __fractsqqq2: Fixed-point fractional library routines. 38485 (line 515) 38486 * __fractsqsa: Fixed-point fractional library routines. 38487 (line 519) 38488 * __fractsqsf: Fixed-point fractional library routines. 38489 (line 537) 38490 * __fractsqsi: Fixed-point fractional library routines. 38491 (line 534) 38492 * __fractsqta: Fixed-point fractional library routines. 38493 (line 521) 38494 * __fractsqti: Fixed-point fractional library routines. 38495 (line 536) 38496 * __fractsquda: Fixed-point fractional library routines. 38497 (line 529) 38498 * __fractsqudq: Fixed-point fractional library routines. 38499 (line 526) 38500 * __fractsquha: Fixed-point fractional library routines. 38501 (line 527) 38502 * __fractsquhq: Fixed-point fractional library routines. 38503 (line 523) 38504 * __fractsquqq: Fixed-point fractional library routines. 38505 (line 522) 38506 * __fractsqusa: Fixed-point fractional library routines. 38507 (line 528) 38508 * __fractsqusq: Fixed-point fractional library routines. 38509 (line 524) 38510 * __fractsquta: Fixed-point fractional library routines. 38511 (line 531) 38512 * __fracttada2: Fixed-point fractional library routines. 38513 (line 643) 38514 * __fracttadf: Fixed-point fractional library routines. 38515 (line 664) 38516 * __fracttadi: Fixed-point fractional library routines. 38517 (line 661) 38518 * __fracttadq: Fixed-point fractional library routines. 38519 (line 640) 38520 * __fracttaha2: Fixed-point fractional library routines. 38521 (line 641) 38522 * __fracttahi: Fixed-point fractional library routines. 38523 (line 659) 38524 * __fracttahq: Fixed-point fractional library routines. 38525 (line 638) 38526 * __fracttaqi: Fixed-point fractional library routines. 38527 (line 658) 38528 * __fracttaqq: Fixed-point fractional library routines. 38529 (line 637) 38530 * __fracttasa2: Fixed-point fractional library routines. 38531 (line 642) 38532 * __fracttasf: Fixed-point fractional library routines. 38533 (line 663) 38534 * __fracttasi: Fixed-point fractional library routines. 38535 (line 660) 38536 * __fracttasq: Fixed-point fractional library routines. 38537 (line 639) 38538 * __fracttati: Fixed-point fractional library routines. 38539 (line 662) 38540 * __fracttauda: Fixed-point fractional library routines. 38541 (line 655) 38542 * __fracttaudq: Fixed-point fractional library routines. 38543 (line 650) 38544 * __fracttauha: Fixed-point fractional library routines. 38545 (line 652) 38546 * __fracttauhq: Fixed-point fractional library routines. 38547 (line 646) 38548 * __fracttauqq: Fixed-point fractional library routines. 38549 (line 645) 38550 * __fracttausa: Fixed-point fractional library routines. 38551 (line 653) 38552 * __fracttausq: Fixed-point fractional library routines. 38553 (line 648) 38554 * __fracttauta: Fixed-point fractional library routines. 38555 (line 657) 38556 * __fracttida: Fixed-point fractional library routines. 38557 (line 991) 38558 * __fracttidq: Fixed-point fractional library routines. 38559 (line 988) 38560 * __fracttiha: Fixed-point fractional library routines. 38561 (line 989) 38562 * __fracttihq: Fixed-point fractional library routines. 38563 (line 986) 38564 * __fracttiqq: Fixed-point fractional library routines. 38565 (line 985) 38566 * __fracttisa: Fixed-point fractional library routines. 38567 (line 990) 38568 * __fracttisq: Fixed-point fractional library routines. 38569 (line 987) 38570 * __fracttita: Fixed-point fractional library routines. 38571 (line 992) 38572 * __fracttiuda: Fixed-point fractional library routines. 38573 (line 1000) 38574 * __fracttiudq: Fixed-point fractional library routines. 38575 (line 997) 38576 * __fracttiuha: Fixed-point fractional library routines. 38577 (line 998) 38578 * __fracttiuhq: Fixed-point fractional library routines. 38579 (line 994) 38580 * __fracttiuqq: Fixed-point fractional library routines. 38581 (line 993) 38582 * __fracttiusa: Fixed-point fractional library routines. 38583 (line 999) 38584 * __fracttiusq: Fixed-point fractional library routines. 38585 (line 995) 38586 * __fracttiuta: Fixed-point fractional library routines. 38587 (line 1002) 38588 * __fractudada: Fixed-point fractional library routines. 38589 (line 858) 38590 * __fractudadf: Fixed-point fractional library routines. 38591 (line 881) 38592 * __fractudadi: Fixed-point fractional library routines. 38593 (line 878) 38594 * __fractudadq: Fixed-point fractional library routines. 38595 (line 855) 38596 * __fractudaha: Fixed-point fractional library routines. 38597 (line 856) 38598 * __fractudahi: Fixed-point fractional library routines. 38599 (line 876) 38600 * __fractudahq: Fixed-point fractional library routines. 38601 (line 852) 38602 * __fractudaqi: Fixed-point fractional library routines. 38603 (line 875) 38604 * __fractudaqq: Fixed-point fractional library routines. 38605 (line 851) 38606 * __fractudasa: Fixed-point fractional library routines. 38607 (line 857) 38608 * __fractudasf: Fixed-point fractional library routines. 38609 (line 880) 38610 * __fractudasi: Fixed-point fractional library routines. 38611 (line 877) 38612 * __fractudasq: Fixed-point fractional library routines. 38613 (line 853) 38614 * __fractudata: Fixed-point fractional library routines. 38615 (line 860) 38616 * __fractudati: Fixed-point fractional library routines. 38617 (line 879) 38618 * __fractudaudq: Fixed-point fractional library routines. 38619 (line 868) 38620 * __fractudauha2: Fixed-point fractional library routines. 38621 (line 870) 38622 * __fractudauhq: Fixed-point fractional library routines. 38623 (line 864) 38624 * __fractudauqq: Fixed-point fractional library routines. 38625 (line 862) 38626 * __fractudausa2: Fixed-point fractional library routines. 38627 (line 872) 38628 * __fractudausq: Fixed-point fractional library routines. 38629 (line 866) 38630 * __fractudauta2: Fixed-point fractional library routines. 38631 (line 874) 38632 * __fractudqda: Fixed-point fractional library routines. 38633 (line 766) 38634 * __fractudqdf: Fixed-point fractional library routines. 38635 (line 791) 38636 * __fractudqdi: Fixed-point fractional library routines. 38637 (line 787) 38638 * __fractudqdq: Fixed-point fractional library routines. 38639 (line 761) 38640 * __fractudqha: Fixed-point fractional library routines. 38641 (line 763) 38642 * __fractudqhi: Fixed-point fractional library routines. 38643 (line 785) 38644 * __fractudqhq: Fixed-point fractional library routines. 38645 (line 757) 38646 * __fractudqqi: Fixed-point fractional library routines. 38647 (line 784) 38648 * __fractudqqq: Fixed-point fractional library routines. 38649 (line 756) 38650 * __fractudqsa: Fixed-point fractional library routines. 38651 (line 764) 38652 * __fractudqsf: Fixed-point fractional library routines. 38653 (line 790) 38654 * __fractudqsi: Fixed-point fractional library routines. 38655 (line 786) 38656 * __fractudqsq: Fixed-point fractional library routines. 38657 (line 759) 38658 * __fractudqta: Fixed-point fractional library routines. 38659 (line 768) 38660 * __fractudqti: Fixed-point fractional library routines. 38661 (line 789) 38662 * __fractudquda: Fixed-point fractional library routines. 38663 (line 780) 38664 * __fractudquha: Fixed-point fractional library routines. 38665 (line 776) 38666 * __fractudquhq2: Fixed-point fractional library routines. 38667 (line 772) 38668 * __fractudquqq2: Fixed-point fractional library routines. 38669 (line 770) 38670 * __fractudqusa: Fixed-point fractional library routines. 38671 (line 778) 38672 * __fractudqusq2: Fixed-point fractional library routines. 38673 (line 774) 38674 * __fractudquta: Fixed-point fractional library routines. 38675 (line 782) 38676 * __fractuhada: Fixed-point fractional library routines. 38677 (line 799) 38678 * __fractuhadf: Fixed-point fractional library routines. 38679 (line 822) 38680 * __fractuhadi: Fixed-point fractional library routines. 38681 (line 819) 38682 * __fractuhadq: Fixed-point fractional library routines. 38683 (line 796) 38684 * __fractuhaha: Fixed-point fractional library routines. 38685 (line 797) 38686 * __fractuhahi: Fixed-point fractional library routines. 38687 (line 817) 38688 * __fractuhahq: Fixed-point fractional library routines. 38689 (line 793) 38690 * __fractuhaqi: Fixed-point fractional library routines. 38691 (line 816) 38692 * __fractuhaqq: Fixed-point fractional library routines. 38693 (line 792) 38694 * __fractuhasa: Fixed-point fractional library routines. 38695 (line 798) 38696 * __fractuhasf: Fixed-point fractional library routines. 38697 (line 821) 38698 * __fractuhasi: Fixed-point fractional library routines. 38699 (line 818) 38700 * __fractuhasq: Fixed-point fractional library routines. 38701 (line 794) 38702 * __fractuhata: Fixed-point fractional library routines. 38703 (line 801) 38704 * __fractuhati: Fixed-point fractional library routines. 38705 (line 820) 38706 * __fractuhauda2: Fixed-point fractional library routines. 38707 (line 813) 38708 * __fractuhaudq: Fixed-point fractional library routines. 38709 (line 809) 38710 * __fractuhauhq: Fixed-point fractional library routines. 38711 (line 805) 38712 * __fractuhauqq: Fixed-point fractional library routines. 38713 (line 803) 38714 * __fractuhausa2: Fixed-point fractional library routines. 38715 (line 811) 38716 * __fractuhausq: Fixed-point fractional library routines. 38717 (line 807) 38718 * __fractuhauta2: Fixed-point fractional library routines. 38719 (line 815) 38720 * __fractuhqda: Fixed-point fractional library routines. 38721 (line 702) 38722 * __fractuhqdf: Fixed-point fractional library routines. 38723 (line 723) 38724 * __fractuhqdi: Fixed-point fractional library routines. 38725 (line 720) 38726 * __fractuhqdq: Fixed-point fractional library routines. 38727 (line 699) 38728 * __fractuhqha: Fixed-point fractional library routines. 38729 (line 700) 38730 * __fractuhqhi: Fixed-point fractional library routines. 38731 (line 718) 38732 * __fractuhqhq: Fixed-point fractional library routines. 38733 (line 697) 38734 * __fractuhqqi: Fixed-point fractional library routines. 38735 (line 717) 38736 * __fractuhqqq: Fixed-point fractional library routines. 38737 (line 696) 38738 * __fractuhqsa: Fixed-point fractional library routines. 38739 (line 701) 38740 * __fractuhqsf: Fixed-point fractional library routines. 38741 (line 722) 38742 * __fractuhqsi: Fixed-point fractional library routines. 38743 (line 719) 38744 * __fractuhqsq: Fixed-point fractional library routines. 38745 (line 698) 38746 * __fractuhqta: Fixed-point fractional library routines. 38747 (line 703) 38748 * __fractuhqti: Fixed-point fractional library routines. 38749 (line 721) 38750 * __fractuhquda: Fixed-point fractional library routines. 38751 (line 714) 38752 * __fractuhqudq2: Fixed-point fractional library routines. 38753 (line 709) 38754 * __fractuhquha: Fixed-point fractional library routines. 38755 (line 711) 38756 * __fractuhquqq2: Fixed-point fractional library routines. 38757 (line 705) 38758 * __fractuhqusa: Fixed-point fractional library routines. 38759 (line 712) 38760 * __fractuhqusq2: Fixed-point fractional library routines. 38761 (line 707) 38762 * __fractuhquta: Fixed-point fractional library routines. 38763 (line 716) 38764 * __fractunsdadi: Fixed-point fractional library routines. 38765 (line 1555) 38766 * __fractunsdahi: Fixed-point fractional library routines. 38767 (line 1553) 38768 * __fractunsdaqi: Fixed-point fractional library routines. 38769 (line 1552) 38770 * __fractunsdasi: Fixed-point fractional library routines. 38771 (line 1554) 38772 * __fractunsdati: Fixed-point fractional library routines. 38773 (line 1556) 38774 * __fractunsdida: Fixed-point fractional library routines. 38775 (line 1707) 38776 * __fractunsdidq: Fixed-point fractional library routines. 38777 (line 1704) 38778 * __fractunsdiha: Fixed-point fractional library routines. 38779 (line 1705) 38780 * __fractunsdihq: Fixed-point fractional library routines. 38781 (line 1702) 38782 * __fractunsdiqq: Fixed-point fractional library routines. 38783 (line 1701) 38784 * __fractunsdisa: Fixed-point fractional library routines. 38785 (line 1706) 38786 * __fractunsdisq: Fixed-point fractional library routines. 38787 (line 1703) 38788 * __fractunsdita: Fixed-point fractional library routines. 38789 (line 1708) 38790 * __fractunsdiuda: Fixed-point fractional library routines. 38791 (line 1720) 38792 * __fractunsdiudq: Fixed-point fractional library routines. 38793 (line 1715) 38794 * __fractunsdiuha: Fixed-point fractional library routines. 38795 (line 1717) 38796 * __fractunsdiuhq: Fixed-point fractional library routines. 38797 (line 1711) 38798 * __fractunsdiuqq: Fixed-point fractional library routines. 38799 (line 1710) 38800 * __fractunsdiusa: Fixed-point fractional library routines. 38801 (line 1718) 38802 * __fractunsdiusq: Fixed-point fractional library routines. 38803 (line 1713) 38804 * __fractunsdiuta: Fixed-point fractional library routines. 38805 (line 1722) 38806 * __fractunsdqdi: Fixed-point fractional library routines. 38807 (line 1539) 38808 * __fractunsdqhi: Fixed-point fractional library routines. 38809 (line 1537) 38810 * __fractunsdqqi: Fixed-point fractional library routines. 38811 (line 1536) 38812 * __fractunsdqsi: Fixed-point fractional library routines. 38813 (line 1538) 38814 * __fractunsdqti: Fixed-point fractional library routines. 38815 (line 1541) 38816 * __fractunshadi: Fixed-point fractional library routines. 38817 (line 1545) 38818 * __fractunshahi: Fixed-point fractional library routines. 38819 (line 1543) 38820 * __fractunshaqi: Fixed-point fractional library routines. 38821 (line 1542) 38822 * __fractunshasi: Fixed-point fractional library routines. 38823 (line 1544) 38824 * __fractunshati: Fixed-point fractional library routines. 38825 (line 1546) 38826 * __fractunshida: Fixed-point fractional library routines. 38827 (line 1663) 38828 * __fractunshidq: Fixed-point fractional library routines. 38829 (line 1660) 38830 * __fractunshiha: Fixed-point fractional library routines. 38831 (line 1661) 38832 * __fractunshihq: Fixed-point fractional library routines. 38833 (line 1658) 38834 * __fractunshiqq: Fixed-point fractional library routines. 38835 (line 1657) 38836 * __fractunshisa: Fixed-point fractional library routines. 38837 (line 1662) 38838 * __fractunshisq: Fixed-point fractional library routines. 38839 (line 1659) 38840 * __fractunshita: Fixed-point fractional library routines. 38841 (line 1664) 38842 * __fractunshiuda: Fixed-point fractional library routines. 38843 (line 1676) 38844 * __fractunshiudq: Fixed-point fractional library routines. 38845 (line 1671) 38846 * __fractunshiuha: Fixed-point fractional library routines. 38847 (line 1673) 38848 * __fractunshiuhq: Fixed-point fractional library routines. 38849 (line 1667) 38850 * __fractunshiuqq: Fixed-point fractional library routines. 38851 (line 1666) 38852 * __fractunshiusa: Fixed-point fractional library routines. 38853 (line 1674) 38854 * __fractunshiusq: Fixed-point fractional library routines. 38855 (line 1669) 38856 * __fractunshiuta: Fixed-point fractional library routines. 38857 (line 1678) 38858 * __fractunshqdi: Fixed-point fractional library routines. 38859 (line 1529) 38860 * __fractunshqhi: Fixed-point fractional library routines. 38861 (line 1527) 38862 * __fractunshqqi: Fixed-point fractional library routines. 38863 (line 1526) 38864 * __fractunshqsi: Fixed-point fractional library routines. 38865 (line 1528) 38866 * __fractunshqti: Fixed-point fractional library routines. 38867 (line 1530) 38868 * __fractunsqida: Fixed-point fractional library routines. 38869 (line 1641) 38870 * __fractunsqidq: Fixed-point fractional library routines. 38871 (line 1638) 38872 * __fractunsqiha: Fixed-point fractional library routines. 38873 (line 1639) 38874 * __fractunsqihq: Fixed-point fractional library routines. 38875 (line 1636) 38876 * __fractunsqiqq: Fixed-point fractional library routines. 38877 (line 1635) 38878 * __fractunsqisa: Fixed-point fractional library routines. 38879 (line 1640) 38880 * __fractunsqisq: Fixed-point fractional library routines. 38881 (line 1637) 38882 * __fractunsqita: Fixed-point fractional library routines. 38883 (line 1642) 38884 * __fractunsqiuda: Fixed-point fractional library routines. 38885 (line 1654) 38886 * __fractunsqiudq: Fixed-point fractional library routines. 38887 (line 1649) 38888 * __fractunsqiuha: Fixed-point fractional library routines. 38889 (line 1651) 38890 * __fractunsqiuhq: Fixed-point fractional library routines. 38891 (line 1645) 38892 * __fractunsqiuqq: Fixed-point fractional library routines. 38893 (line 1644) 38894 * __fractunsqiusa: Fixed-point fractional library routines. 38895 (line 1652) 38896 * __fractunsqiusq: Fixed-point fractional library routines. 38897 (line 1647) 38898 * __fractunsqiuta: Fixed-point fractional library routines. 38899 (line 1656) 38900 * __fractunsqqdi: Fixed-point fractional library routines. 38901 (line 1524) 38902 * __fractunsqqhi: Fixed-point fractional library routines. 38903 (line 1522) 38904 * __fractunsqqqi: Fixed-point fractional library routines. 38905 (line 1521) 38906 * __fractunsqqsi: Fixed-point fractional library routines. 38907 (line 1523) 38908 * __fractunsqqti: Fixed-point fractional library routines. 38909 (line 1525) 38910 * __fractunssadi: Fixed-point fractional library routines. 38911 (line 1550) 38912 * __fractunssahi: Fixed-point fractional library routines. 38913 (line 1548) 38914 * __fractunssaqi: Fixed-point fractional library routines. 38915 (line 1547) 38916 * __fractunssasi: Fixed-point fractional library routines. 38917 (line 1549) 38918 * __fractunssati: Fixed-point fractional library routines. 38919 (line 1551) 38920 * __fractunssida: Fixed-point fractional library routines. 38921 (line 1685) 38922 * __fractunssidq: Fixed-point fractional library routines. 38923 (line 1682) 38924 * __fractunssiha: Fixed-point fractional library routines. 38925 (line 1683) 38926 * __fractunssihq: Fixed-point fractional library routines. 38927 (line 1680) 38928 * __fractunssiqq: Fixed-point fractional library routines. 38929 (line 1679) 38930 * __fractunssisa: Fixed-point fractional library routines. 38931 (line 1684) 38932 * __fractunssisq: Fixed-point fractional library routines. 38933 (line 1681) 38934 * __fractunssita: Fixed-point fractional library routines. 38935 (line 1686) 38936 * __fractunssiuda: Fixed-point fractional library routines. 38937 (line 1698) 38938 * __fractunssiudq: Fixed-point fractional library routines. 38939 (line 1693) 38940 * __fractunssiuha: Fixed-point fractional library routines. 38941 (line 1695) 38942 * __fractunssiuhq: Fixed-point fractional library routines. 38943 (line 1689) 38944 * __fractunssiuqq: Fixed-point fractional library routines. 38945 (line 1688) 38946 * __fractunssiusa: Fixed-point fractional library routines. 38947 (line 1696) 38948 * __fractunssiusq: Fixed-point fractional library routines. 38949 (line 1691) 38950 * __fractunssiuta: Fixed-point fractional library routines. 38951 (line 1700) 38952 * __fractunssqdi: Fixed-point fractional library routines. 38953 (line 1534) 38954 * __fractunssqhi: Fixed-point fractional library routines. 38955 (line 1532) 38956 * __fractunssqqi: Fixed-point fractional library routines. 38957 (line 1531) 38958 * __fractunssqsi: Fixed-point fractional library routines. 38959 (line 1533) 38960 * __fractunssqti: Fixed-point fractional library routines. 38961 (line 1535) 38962 * __fractunstadi: Fixed-point fractional library routines. 38963 (line 1560) 38964 * __fractunstahi: Fixed-point fractional library routines. 38965 (line 1558) 38966 * __fractunstaqi: Fixed-point fractional library routines. 38967 (line 1557) 38968 * __fractunstasi: Fixed-point fractional library routines. 38969 (line 1559) 38970 * __fractunstati: Fixed-point fractional library routines. 38971 (line 1562) 38972 * __fractunstida: Fixed-point fractional library routines. 38973 (line 1730) 38974 * __fractunstidq: Fixed-point fractional library routines. 38975 (line 1727) 38976 * __fractunstiha: Fixed-point fractional library routines. 38977 (line 1728) 38978 * __fractunstihq: Fixed-point fractional library routines. 38979 (line 1724) 38980 * __fractunstiqq: Fixed-point fractional library routines. 38981 (line 1723) 38982 * __fractunstisa: Fixed-point fractional library routines. 38983 (line 1729) 38984 * __fractunstisq: Fixed-point fractional library routines. 38985 (line 1725) 38986 * __fractunstita: Fixed-point fractional library routines. 38987 (line 1732) 38988 * __fractunstiuda: Fixed-point fractional library routines. 38989 (line 1746) 38990 * __fractunstiudq: Fixed-point fractional library routines. 38991 (line 1740) 38992 * __fractunstiuha: Fixed-point fractional library routines. 38993 (line 1742) 38994 * __fractunstiuhq: Fixed-point fractional library routines. 38995 (line 1736) 38996 * __fractunstiuqq: Fixed-point fractional library routines. 38997 (line 1734) 38998 * __fractunstiusa: Fixed-point fractional library routines. 38999 (line 1744) 39000 * __fractunstiusq: Fixed-point fractional library routines. 39001 (line 1738) 39002 * __fractunstiuta: Fixed-point fractional library routines. 39003 (line 1748) 39004 * __fractunsudadi: Fixed-point fractional library routines. 39005 (line 1622) 39006 * __fractunsudahi: Fixed-point fractional library routines. 39007 (line 1618) 39008 * __fractunsudaqi: Fixed-point fractional library routines. 39009 (line 1616) 39010 * __fractunsudasi: Fixed-point fractional library routines. 39011 (line 1620) 39012 * __fractunsudati: Fixed-point fractional library routines. 39013 (line 1624) 39014 * __fractunsudqdi: Fixed-point fractional library routines. 39015 (line 1596) 39016 * __fractunsudqhi: Fixed-point fractional library routines. 39017 (line 1592) 39018 * __fractunsudqqi: Fixed-point fractional library routines. 39019 (line 1590) 39020 * __fractunsudqsi: Fixed-point fractional library routines. 39021 (line 1594) 39022 * __fractunsudqti: Fixed-point fractional library routines. 39023 (line 1598) 39024 * __fractunsuhadi: Fixed-point fractional library routines. 39025 (line 1606) 39026 * __fractunsuhahi: Fixed-point fractional library routines. 39027 (line 1602) 39028 * __fractunsuhaqi: Fixed-point fractional library routines. 39029 (line 1600) 39030 * __fractunsuhasi: Fixed-point fractional library routines. 39031 (line 1604) 39032 * __fractunsuhati: Fixed-point fractional library routines. 39033 (line 1608) 39034 * __fractunsuhqdi: Fixed-point fractional library routines. 39035 (line 1576) 39036 * __fractunsuhqhi: Fixed-point fractional library routines. 39037 (line 1574) 39038 * __fractunsuhqqi: Fixed-point fractional library routines. 39039 (line 1573) 39040 * __fractunsuhqsi: Fixed-point fractional library routines. 39041 (line 1575) 39042 * __fractunsuhqti: Fixed-point fractional library routines. 39043 (line 1578) 39044 * __fractunsuqqdi: Fixed-point fractional library routines. 39045 (line 1570) 39046 * __fractunsuqqhi: Fixed-point fractional library routines. 39047 (line 1566) 39048 * __fractunsuqqqi: Fixed-point fractional library routines. 39049 (line 1564) 39050 * __fractunsuqqsi: Fixed-point fractional library routines. 39051 (line 1568) 39052 * __fractunsuqqti: Fixed-point fractional library routines. 39053 (line 1572) 39054 * __fractunsusadi: Fixed-point fractional library routines. 39055 (line 1612) 39056 * __fractunsusahi: Fixed-point fractional library routines. 39057 (line 1610) 39058 * __fractunsusaqi: Fixed-point fractional library routines. 39059 (line 1609) 39060 * __fractunsusasi: Fixed-point fractional library routines. 39061 (line 1611) 39062 * __fractunsusati: Fixed-point fractional library routines. 39063 (line 1614) 39064 * __fractunsusqdi: Fixed-point fractional library routines. 39065 (line 1586) 39066 * __fractunsusqhi: Fixed-point fractional library routines. 39067 (line 1582) 39068 * __fractunsusqqi: Fixed-point fractional library routines. 39069 (line 1580) 39070 * __fractunsusqsi: Fixed-point fractional library routines. 39071 (line 1584) 39072 * __fractunsusqti: Fixed-point fractional library routines. 39073 (line 1588) 39074 * __fractunsutadi: Fixed-point fractional library routines. 39075 (line 1632) 39076 * __fractunsutahi: Fixed-point fractional library routines. 39077 (line 1628) 39078 * __fractunsutaqi: Fixed-point fractional library routines. 39079 (line 1626) 39080 * __fractunsutasi: Fixed-point fractional library routines. 39081 (line 1630) 39082 * __fractunsutati: Fixed-point fractional library routines. 39083 (line 1634) 39084 * __fractuqqda: Fixed-point fractional library routines. 39085 (line 672) 39086 * __fractuqqdf: Fixed-point fractional library routines. 39087 (line 695) 39088 * __fractuqqdi: Fixed-point fractional library routines. 39089 (line 692) 39090 * __fractuqqdq: Fixed-point fractional library routines. 39091 (line 669) 39092 * __fractuqqha: Fixed-point fractional library routines. 39093 (line 670) 39094 * __fractuqqhi: Fixed-point fractional library routines. 39095 (line 690) 39096 * __fractuqqhq: Fixed-point fractional library routines. 39097 (line 666) 39098 * __fractuqqqi: Fixed-point fractional library routines. 39099 (line 689) 39100 * __fractuqqqq: Fixed-point fractional library routines. 39101 (line 665) 39102 * __fractuqqsa: Fixed-point fractional library routines. 39103 (line 671) 39104 * __fractuqqsf: Fixed-point fractional library routines. 39105 (line 694) 39106 * __fractuqqsi: Fixed-point fractional library routines. 39107 (line 691) 39108 * __fractuqqsq: Fixed-point fractional library routines. 39109 (line 667) 39110 * __fractuqqta: Fixed-point fractional library routines. 39111 (line 674) 39112 * __fractuqqti: Fixed-point fractional library routines. 39113 (line 693) 39114 * __fractuqquda: Fixed-point fractional library routines. 39115 (line 686) 39116 * __fractuqqudq2: Fixed-point fractional library routines. 39117 (line 680) 39118 * __fractuqquha: Fixed-point fractional library routines. 39119 (line 682) 39120 * __fractuqquhq2: Fixed-point fractional library routines. 39121 (line 676) 39122 * __fractuqqusa: Fixed-point fractional library routines. 39123 (line 684) 39124 * __fractuqqusq2: Fixed-point fractional library routines. 39125 (line 678) 39126 * __fractuqquta: Fixed-point fractional library routines. 39127 (line 688) 39128 * __fractusada: Fixed-point fractional library routines. 39129 (line 829) 39130 * __fractusadf: Fixed-point fractional library routines. 39131 (line 850) 39132 * __fractusadi: Fixed-point fractional library routines. 39133 (line 847) 39134 * __fractusadq: Fixed-point fractional library routines. 39135 (line 826) 39136 * __fractusaha: Fixed-point fractional library routines. 39137 (line 827) 39138 * __fractusahi: Fixed-point fractional library routines. 39139 (line 845) 39140 * __fractusahq: Fixed-point fractional library routines. 39141 (line 824) 39142 * __fractusaqi: Fixed-point fractional library routines. 39143 (line 844) 39144 * __fractusaqq: Fixed-point fractional library routines. 39145 (line 823) 39146 * __fractusasa: Fixed-point fractional library routines. 39147 (line 828) 39148 * __fractusasf: Fixed-point fractional library routines. 39149 (line 849) 39150 * __fractusasi: Fixed-point fractional library routines. 39151 (line 846) 39152 * __fractusasq: Fixed-point fractional library routines. 39153 (line 825) 39154 * __fractusata: Fixed-point fractional library routines. 39155 (line 830) 39156 * __fractusati: Fixed-point fractional library routines. 39157 (line 848) 39158 * __fractusauda2: Fixed-point fractional library routines. 39159 (line 841) 39160 * __fractusaudq: Fixed-point fractional library routines. 39161 (line 837) 39162 * __fractusauha2: Fixed-point fractional library routines. 39163 (line 839) 39164 * __fractusauhq: Fixed-point fractional library routines. 39165 (line 833) 39166 * __fractusauqq: Fixed-point fractional library routines. 39167 (line 832) 39168 * __fractusausq: Fixed-point fractional library routines. 39169 (line 835) 39170 * __fractusauta2: Fixed-point fractional library routines. 39171 (line 843) 39172 * __fractusqda: Fixed-point fractional library routines. 39173 (line 731) 39174 * __fractusqdf: Fixed-point fractional library routines. 39175 (line 754) 39176 * __fractusqdi: Fixed-point fractional library routines. 39177 (line 751) 39178 * __fractusqdq: Fixed-point fractional library routines. 39179 (line 728) 39180 * __fractusqha: Fixed-point fractional library routines. 39181 (line 729) 39182 * __fractusqhi: Fixed-point fractional library routines. 39183 (line 749) 39184 * __fractusqhq: Fixed-point fractional library routines. 39185 (line 725) 39186 * __fractusqqi: Fixed-point fractional library routines. 39187 (line 748) 39188 * __fractusqqq: Fixed-point fractional library routines. 39189 (line 724) 39190 * __fractusqsa: Fixed-point fractional library routines. 39191 (line 730) 39192 * __fractusqsf: Fixed-point fractional library routines. 39193 (line 753) 39194 * __fractusqsi: Fixed-point fractional library routines. 39195 (line 750) 39196 * __fractusqsq: Fixed-point fractional library routines. 39197 (line 726) 39198 * __fractusqta: Fixed-point fractional library routines. 39199 (line 733) 39200 * __fractusqti: Fixed-point fractional library routines. 39201 (line 752) 39202 * __fractusquda: Fixed-point fractional library routines. 39203 (line 745) 39204 * __fractusqudq2: Fixed-point fractional library routines. 39205 (line 739) 39206 * __fractusquha: Fixed-point fractional library routines. 39207 (line 741) 39208 * __fractusquhq2: Fixed-point fractional library routines. 39209 (line 737) 39210 * __fractusquqq2: Fixed-point fractional library routines. 39211 (line 735) 39212 * __fractusqusa: Fixed-point fractional library routines. 39213 (line 743) 39214 * __fractusquta: Fixed-point fractional library routines. 39215 (line 747) 39216 * __fractutada: Fixed-point fractional library routines. 39217 (line 893) 39218 * __fractutadf: Fixed-point fractional library routines. 39219 (line 918) 39220 * __fractutadi: Fixed-point fractional library routines. 39221 (line 914) 39222 * __fractutadq: Fixed-point fractional library routines. 39223 (line 888) 39224 * __fractutaha: Fixed-point fractional library routines. 39225 (line 890) 39226 * __fractutahi: Fixed-point fractional library routines. 39227 (line 912) 39228 * __fractutahq: Fixed-point fractional library routines. 39229 (line 884) 39230 * __fractutaqi: Fixed-point fractional library routines. 39231 (line 911) 39232 * __fractutaqq: Fixed-point fractional library routines. 39233 (line 883) 39234 * __fractutasa: Fixed-point fractional library routines. 39235 (line 891) 39236 * __fractutasf: Fixed-point fractional library routines. 39237 (line 917) 39238 * __fractutasi: Fixed-point fractional library routines. 39239 (line 913) 39240 * __fractutasq: Fixed-point fractional library routines. 39241 (line 886) 39242 * __fractutata: Fixed-point fractional library routines. 39243 (line 895) 39244 * __fractutati: Fixed-point fractional library routines. 39245 (line 916) 39246 * __fractutauda2: Fixed-point fractional library routines. 39247 (line 909) 39248 * __fractutaudq: Fixed-point fractional library routines. 39249 (line 903) 39250 * __fractutauha2: Fixed-point fractional library routines. 39251 (line 905) 39252 * __fractutauhq: Fixed-point fractional library routines. 39253 (line 899) 39254 * __fractutauqq: Fixed-point fractional library routines. 39255 (line 897) 39256 * __fractutausa2: Fixed-point fractional library routines. 39257 (line 907) 39258 * __fractutausq: Fixed-point fractional library routines. 39259 (line 901) 39260 * __gedf2: Soft float library routines. 39261 (line 206) 39262 * __gesf2: Soft float library routines. 39263 (line 205) 39264 * __getf2: Soft float library routines. 39265 (line 207) 39266 * __gtdf2: Soft float library routines. 39267 (line 224) 39268 * __gtsf2: Soft float library routines. 39269 (line 223) 39270 * __gttf2: Soft float library routines. 39271 (line 225) 39272 * __ledf2: Soft float library routines. 39273 (line 218) 39274 * __lesf2: Soft float library routines. 39275 (line 217) 39276 * __letf2: Soft float library routines. 39277 (line 219) 39278 * __lshrdi3: Integer library routines. 39279 (line 31) 39280 * __lshrsi3: Integer library routines. 39281 (line 30) 39282 * __lshrti3: Integer library routines. 39283 (line 32) 39284 * __lshruda3: Fixed-point fractional library routines. 39285 (line 390) 39286 * __lshrudq3: Fixed-point fractional library routines. 39287 (line 384) 39288 * __lshruha3: Fixed-point fractional library routines. 39289 (line 386) 39290 * __lshruhq3: Fixed-point fractional library routines. 39291 (line 380) 39292 * __lshruqq3: Fixed-point fractional library routines. 39293 (line 378) 39294 * __lshrusa3: Fixed-point fractional library routines. 39295 (line 388) 39296 * __lshrusq3: Fixed-point fractional library routines. 39297 (line 382) 39298 * __lshruta3: Fixed-point fractional library routines. 39299 (line 392) 39300 * __ltdf2: Soft float library routines. 39301 (line 212) 39302 * __ltsf2: Soft float library routines. 39303 (line 211) 39304 * __lttf2: Soft float library routines. 39305 (line 213) 39306 * __main: Collect2. (line 15) 39307 * __moddi3: Integer library routines. 39308 (line 37) 39309 * __modsi3: Integer library routines. 39310 (line 36) 39311 * __modti3: Integer library routines. 39312 (line 38) 39313 * __mulda3: Fixed-point fractional library routines. 39314 (line 171) 39315 * __muldc3: Soft float library routines. 39316 (line 241) 39317 * __muldf3: Soft float library routines. 39318 (line 40) 39319 * __muldi3: Integer library routines. 39320 (line 43) 39321 * __muldq3: Fixed-point fractional library routines. 39322 (line 159) 39323 * __mulha3: Fixed-point fractional library routines. 39324 (line 169) 39325 * __mulhq3: Fixed-point fractional library routines. 39326 (line 156) 39327 * __mulqq3: Fixed-point fractional library routines. 39328 (line 155) 39329 * __mulsa3: Fixed-point fractional library routines. 39330 (line 170) 39331 * __mulsc3: Soft float library routines. 39332 (line 239) 39333 * __mulsf3: Soft float library routines. 39334 (line 39) 39335 * __mulsi3: Integer library routines. 39336 (line 42) 39337 * __mulsq3: Fixed-point fractional library routines. 39338 (line 157) 39339 * __multa3: Fixed-point fractional library routines. 39340 (line 173) 39341 * __multc3: Soft float library routines. 39342 (line 243) 39343 * __multf3: Soft float library routines. 39344 (line 42) 39345 * __multi3: Integer library routines. 39346 (line 44) 39347 * __muluda3: Fixed-point fractional library routines. 39348 (line 179) 39349 * __muludq3: Fixed-point fractional library routines. 39350 (line 167) 39351 * __muluha3: Fixed-point fractional library routines. 39352 (line 175) 39353 * __muluhq3: Fixed-point fractional library routines. 39354 (line 163) 39355 * __muluqq3: Fixed-point fractional library routines. 39356 (line 161) 39357 * __mulusa3: Fixed-point fractional library routines. 39358 (line 177) 39359 * __mulusq3: Fixed-point fractional library routines. 39360 (line 165) 39361 * __muluta3: Fixed-point fractional library routines. 39362 (line 181) 39363 * __mulvdi3: Integer library routines. 39364 (line 115) 39365 * __mulvsi3: Integer library routines. 39366 (line 114) 39367 * __mulxc3: Soft float library routines. 39368 (line 245) 39369 * __mulxf3: Soft float library routines. 39370 (line 44) 39371 * __nedf2: Soft float library routines. 39372 (line 200) 39373 * __negda2: Fixed-point fractional library routines. 39374 (line 299) 39375 * __negdf2: Soft float library routines. 39376 (line 56) 39377 * __negdi2: Integer library routines. 39378 (line 47) 39379 * __negdq2: Fixed-point fractional library routines. 39380 (line 289) 39381 * __negha2: Fixed-point fractional library routines. 39382 (line 297) 39383 * __neghq2: Fixed-point fractional library routines. 39384 (line 287) 39385 * __negqq2: Fixed-point fractional library routines. 39386 (line 286) 39387 * __negsa2: Fixed-point fractional library routines. 39388 (line 298) 39389 * __negsf2: Soft float library routines. 39390 (line 55) 39391 * __negsq2: Fixed-point fractional library routines. 39392 (line 288) 39393 * __negta2: Fixed-point fractional library routines. 39394 (line 300) 39395 * __negtf2: Soft float library routines. 39396 (line 57) 39397 * __negti2: Integer library routines. 39398 (line 48) 39399 * __neguda2: Fixed-point fractional library routines. 39400 (line 305) 39401 * __negudq2: Fixed-point fractional library routines. 39402 (line 296) 39403 * __neguha2: Fixed-point fractional library routines. 39404 (line 302) 39405 * __neguhq2: Fixed-point fractional library routines. 39406 (line 292) 39407 * __neguqq2: Fixed-point fractional library routines. 39408 (line 291) 39409 * __negusa2: Fixed-point fractional library routines. 39410 (line 303) 39411 * __negusq2: Fixed-point fractional library routines. 39412 (line 294) 39413 * __neguta2: Fixed-point fractional library routines. 39414 (line 307) 39415 * __negvdi2: Integer library routines. 39416 (line 119) 39417 * __negvsi2: Integer library routines. 39418 (line 118) 39419 * __negxf2: Soft float library routines. 39420 (line 58) 39421 * __nesf2: Soft float library routines. 39422 (line 199) 39423 * __netf2: Soft float library routines. 39424 (line 201) 39425 * __paritydi2: Integer library routines. 39426 (line 151) 39427 * __paritysi2: Integer library routines. 39428 (line 150) 39429 * __parityti2: Integer library routines. 39430 (line 152) 39431 * __popcountdi2: Integer library routines. 39432 (line 157) 39433 * __popcountsi2: Integer library routines. 39434 (line 156) 39435 * __popcountti2: Integer library routines. 39436 (line 158) 39437 * __powidf2: Soft float library routines. 39438 (line 233) 39439 * __powisf2: Soft float library routines. 39440 (line 232) 39441 * __powitf2: Soft float library routines. 39442 (line 234) 39443 * __powixf2: Soft float library routines. 39444 (line 235) 39445 * __satfractdadq: Fixed-point fractional library routines. 39446 (line 1153) 39447 * __satfractdaha2: Fixed-point fractional library routines. 39448 (line 1154) 39449 * __satfractdahq: Fixed-point fractional library routines. 39450 (line 1151) 39451 * __satfractdaqq: Fixed-point fractional library routines. 39452 (line 1150) 39453 * __satfractdasa2: Fixed-point fractional library routines. 39454 (line 1155) 39455 * __satfractdasq: Fixed-point fractional library routines. 39456 (line 1152) 39457 * __satfractdata2: Fixed-point fractional library routines. 39458 (line 1156) 39459 * __satfractdauda: Fixed-point fractional library routines. 39460 (line 1166) 39461 * __satfractdaudq: Fixed-point fractional library routines. 39462 (line 1162) 39463 * __satfractdauha: Fixed-point fractional library routines. 39464 (line 1164) 39465 * __satfractdauhq: Fixed-point fractional library routines. 39466 (line 1159) 39467 * __satfractdauqq: Fixed-point fractional library routines. 39468 (line 1158) 39469 * __satfractdausa: Fixed-point fractional library routines. 39470 (line 1165) 39471 * __satfractdausq: Fixed-point fractional library routines. 39472 (line 1160) 39473 * __satfractdauta: Fixed-point fractional library routines. 39474 (line 1168) 39475 * __satfractdfda: Fixed-point fractional library routines. 39476 (line 1506) 39477 * __satfractdfdq: Fixed-point fractional library routines. 39478 (line 1503) 39479 * __satfractdfha: Fixed-point fractional library routines. 39480 (line 1504) 39481 * __satfractdfhq: Fixed-point fractional library routines. 39482 (line 1501) 39483 * __satfractdfqq: Fixed-point fractional library routines. 39484 (line 1500) 39485 * __satfractdfsa: Fixed-point fractional library routines. 39486 (line 1505) 39487 * __satfractdfsq: Fixed-point fractional library routines. 39488 (line 1502) 39489 * __satfractdfta: Fixed-point fractional library routines. 39490 (line 1507) 39491 * __satfractdfuda: Fixed-point fractional library routines. 39492 (line 1515) 39493 * __satfractdfudq: Fixed-point fractional library routines. 39494 (line 1512) 39495 * __satfractdfuha: Fixed-point fractional library routines. 39496 (line 1513) 39497 * __satfractdfuhq: Fixed-point fractional library routines. 39498 (line 1509) 39499 * __satfractdfuqq: Fixed-point fractional library routines. 39500 (line 1508) 39501 * __satfractdfusa: Fixed-point fractional library routines. 39502 (line 1514) 39503 * __satfractdfusq: Fixed-point fractional library routines. 39504 (line 1510) 39505 * __satfractdfuta: Fixed-point fractional library routines. 39506 (line 1517) 39507 * __satfractdida: Fixed-point fractional library routines. 39508 (line 1456) 39509 * __satfractdidq: Fixed-point fractional library routines. 39510 (line 1453) 39511 * __satfractdiha: Fixed-point fractional library routines. 39512 (line 1454) 39513 * __satfractdihq: Fixed-point fractional library routines. 39514 (line 1451) 39515 * __satfractdiqq: Fixed-point fractional library routines. 39516 (line 1450) 39517 * __satfractdisa: Fixed-point fractional library routines. 39518 (line 1455) 39519 * __satfractdisq: Fixed-point fractional library routines. 39520 (line 1452) 39521 * __satfractdita: Fixed-point fractional library routines. 39522 (line 1457) 39523 * __satfractdiuda: Fixed-point fractional library routines. 39524 (line 1464) 39525 * __satfractdiudq: Fixed-point fractional library routines. 39526 (line 1461) 39527 * __satfractdiuha: Fixed-point fractional library routines. 39528 (line 1462) 39529 * __satfractdiuhq: Fixed-point fractional library routines. 39530 (line 1459) 39531 * __satfractdiuqq: Fixed-point fractional library routines. 39532 (line 1458) 39533 * __satfractdiusa: Fixed-point fractional library routines. 39534 (line 1463) 39535 * __satfractdiusq: Fixed-point fractional library routines. 39536 (line 1460) 39537 * __satfractdiuta: Fixed-point fractional library routines. 39538 (line 1465) 39539 * __satfractdqda: Fixed-point fractional library routines. 39540 (line 1098) 39541 * __satfractdqha: Fixed-point fractional library routines. 39542 (line 1096) 39543 * __satfractdqhq2: Fixed-point fractional library routines. 39544 (line 1094) 39545 * __satfractdqqq2: Fixed-point fractional library routines. 39546 (line 1093) 39547 * __satfractdqsa: Fixed-point fractional library routines. 39548 (line 1097) 39549 * __satfractdqsq2: Fixed-point fractional library routines. 39550 (line 1095) 39551 * __satfractdqta: Fixed-point fractional library routines. 39552 (line 1099) 39553 * __satfractdquda: Fixed-point fractional library routines. 39554 (line 1111) 39555 * __satfractdqudq: Fixed-point fractional library routines. 39556 (line 1106) 39557 * __satfractdquha: Fixed-point fractional library routines. 39558 (line 1108) 39559 * __satfractdquhq: Fixed-point fractional library routines. 39560 (line 1102) 39561 * __satfractdquqq: Fixed-point fractional library routines. 39562 (line 1101) 39563 * __satfractdqusa: Fixed-point fractional library routines. 39564 (line 1109) 39565 * __satfractdqusq: Fixed-point fractional library routines. 39566 (line 1104) 39567 * __satfractdquta: Fixed-point fractional library routines. 39568 (line 1113) 39569 * __satfracthada2: Fixed-point fractional library routines. 39570 (line 1119) 39571 * __satfracthadq: Fixed-point fractional library routines. 39572 (line 1117) 39573 * __satfracthahq: Fixed-point fractional library routines. 39574 (line 1115) 39575 * __satfracthaqq: Fixed-point fractional library routines. 39576 (line 1114) 39577 * __satfracthasa2: Fixed-point fractional library routines. 39578 (line 1118) 39579 * __satfracthasq: Fixed-point fractional library routines. 39580 (line 1116) 39581 * __satfracthata2: Fixed-point fractional library routines. 39582 (line 1120) 39583 * __satfracthauda: Fixed-point fractional library routines. 39584 (line 1132) 39585 * __satfracthaudq: Fixed-point fractional library routines. 39586 (line 1127) 39587 * __satfracthauha: Fixed-point fractional library routines. 39588 (line 1129) 39589 * __satfracthauhq: Fixed-point fractional library routines. 39590 (line 1123) 39591 * __satfracthauqq: Fixed-point fractional library routines. 39592 (line 1122) 39593 * __satfracthausa: Fixed-point fractional library routines. 39594 (line 1130) 39595 * __satfracthausq: Fixed-point fractional library routines. 39596 (line 1125) 39597 * __satfracthauta: Fixed-point fractional library routines. 39598 (line 1134) 39599 * __satfracthida: Fixed-point fractional library routines. 39600 (line 1424) 39601 * __satfracthidq: Fixed-point fractional library routines. 39602 (line 1421) 39603 * __satfracthiha: Fixed-point fractional library routines. 39604 (line 1422) 39605 * __satfracthihq: Fixed-point fractional library routines. 39606 (line 1419) 39607 * __satfracthiqq: Fixed-point fractional library routines. 39608 (line 1418) 39609 * __satfracthisa: Fixed-point fractional library routines. 39610 (line 1423) 39611 * __satfracthisq: Fixed-point fractional library routines. 39612 (line 1420) 39613 * __satfracthita: Fixed-point fractional library routines. 39614 (line 1425) 39615 * __satfracthiuda: Fixed-point fractional library routines. 39616 (line 1432) 39617 * __satfracthiudq: Fixed-point fractional library routines. 39618 (line 1429) 39619 * __satfracthiuha: Fixed-point fractional library routines. 39620 (line 1430) 39621 * __satfracthiuhq: Fixed-point fractional library routines. 39622 (line 1427) 39623 * __satfracthiuqq: Fixed-point fractional library routines. 39624 (line 1426) 39625 * __satfracthiusa: Fixed-point fractional library routines. 39626 (line 1431) 39627 * __satfracthiusq: Fixed-point fractional library routines. 39628 (line 1428) 39629 * __satfracthiuta: Fixed-point fractional library routines. 39630 (line 1433) 39631 * __satfracthqda: Fixed-point fractional library routines. 39632 (line 1064) 39633 * __satfracthqdq2: Fixed-point fractional library routines. 39634 (line 1061) 39635 * __satfracthqha: Fixed-point fractional library routines. 39636 (line 1062) 39637 * __satfracthqqq2: Fixed-point fractional library routines. 39638 (line 1059) 39639 * __satfracthqsa: Fixed-point fractional library routines. 39640 (line 1063) 39641 * __satfracthqsq2: Fixed-point fractional library routines. 39642 (line 1060) 39643 * __satfracthqta: Fixed-point fractional library routines. 39644 (line 1065) 39645 * __satfracthquda: Fixed-point fractional library routines. 39646 (line 1072) 39647 * __satfracthqudq: Fixed-point fractional library routines. 39648 (line 1069) 39649 * __satfracthquha: Fixed-point fractional library routines. 39650 (line 1070) 39651 * __satfracthquhq: Fixed-point fractional library routines. 39652 (line 1067) 39653 * __satfracthquqq: Fixed-point fractional library routines. 39654 (line 1066) 39655 * __satfracthqusa: Fixed-point fractional library routines. 39656 (line 1071) 39657 * __satfracthqusq: Fixed-point fractional library routines. 39658 (line 1068) 39659 * __satfracthquta: Fixed-point fractional library routines. 39660 (line 1073) 39661 * __satfractqida: Fixed-point fractional library routines. 39662 (line 1402) 39663 * __satfractqidq: Fixed-point fractional library routines. 39664 (line 1399) 39665 * __satfractqiha: Fixed-point fractional library routines. 39666 (line 1400) 39667 * __satfractqihq: Fixed-point fractional library routines. 39668 (line 1397) 39669 * __satfractqiqq: Fixed-point fractional library routines. 39670 (line 1396) 39671 * __satfractqisa: Fixed-point fractional library routines. 39672 (line 1401) 39673 * __satfractqisq: Fixed-point fractional library routines. 39674 (line 1398) 39675 * __satfractqita: Fixed-point fractional library routines. 39676 (line 1403) 39677 * __satfractqiuda: Fixed-point fractional library routines. 39678 (line 1415) 39679 * __satfractqiudq: Fixed-point fractional library routines. 39680 (line 1410) 39681 * __satfractqiuha: Fixed-point fractional library routines. 39682 (line 1412) 39683 * __satfractqiuhq: Fixed-point fractional library routines. 39684 (line 1406) 39685 * __satfractqiuqq: Fixed-point fractional library routines. 39686 (line 1405) 39687 * __satfractqiusa: Fixed-point fractional library routines. 39688 (line 1413) 39689 * __satfractqiusq: Fixed-point fractional library routines. 39690 (line 1408) 39691 * __satfractqiuta: Fixed-point fractional library routines. 39692 (line 1417) 39693 * __satfractqqda: Fixed-point fractional library routines. 39694 (line 1043) 39695 * __satfractqqdq2: Fixed-point fractional library routines. 39696 (line 1040) 39697 * __satfractqqha: Fixed-point fractional library routines. 39698 (line 1041) 39699 * __satfractqqhq2: Fixed-point fractional library routines. 39700 (line 1038) 39701 * __satfractqqsa: Fixed-point fractional library routines. 39702 (line 1042) 39703 * __satfractqqsq2: Fixed-point fractional library routines. 39704 (line 1039) 39705 * __satfractqqta: Fixed-point fractional library routines. 39706 (line 1044) 39707 * __satfractqquda: Fixed-point fractional library routines. 39708 (line 1056) 39709 * __satfractqqudq: Fixed-point fractional library routines. 39710 (line 1051) 39711 * __satfractqquha: Fixed-point fractional library routines. 39712 (line 1053) 39713 * __satfractqquhq: Fixed-point fractional library routines. 39714 (line 1047) 39715 * __satfractqquqq: Fixed-point fractional library routines. 39716 (line 1046) 39717 * __satfractqqusa: Fixed-point fractional library routines. 39718 (line 1054) 39719 * __satfractqqusq: Fixed-point fractional library routines. 39720 (line 1049) 39721 * __satfractqquta: Fixed-point fractional library routines. 39722 (line 1058) 39723 * __satfractsada2: Fixed-point fractional library routines. 39724 (line 1140) 39725 * __satfractsadq: Fixed-point fractional library routines. 39726 (line 1138) 39727 * __satfractsaha2: Fixed-point fractional library routines. 39728 (line 1139) 39729 * __satfractsahq: Fixed-point fractional library routines. 39730 (line 1136) 39731 * __satfractsaqq: Fixed-point fractional library routines. 39732 (line 1135) 39733 * __satfractsasq: Fixed-point fractional library routines. 39734 (line 1137) 39735 * __satfractsata2: Fixed-point fractional library routines. 39736 (line 1141) 39737 * __satfractsauda: Fixed-point fractional library routines. 39738 (line 1148) 39739 * __satfractsaudq: Fixed-point fractional library routines. 39740 (line 1145) 39741 * __satfractsauha: Fixed-point fractional library routines. 39742 (line 1146) 39743 * __satfractsauhq: Fixed-point fractional library routines. 39744 (line 1143) 39745 * __satfractsauqq: Fixed-point fractional library routines. 39746 (line 1142) 39747 * __satfractsausa: Fixed-point fractional library routines. 39748 (line 1147) 39749 * __satfractsausq: Fixed-point fractional library routines. 39750 (line 1144) 39751 * __satfractsauta: Fixed-point fractional library routines. 39752 (line 1149) 39753 * __satfractsfda: Fixed-point fractional library routines. 39754 (line 1490) 39755 * __satfractsfdq: Fixed-point fractional library routines. 39756 (line 1487) 39757 * __satfractsfha: Fixed-point fractional library routines. 39758 (line 1488) 39759 * __satfractsfhq: Fixed-point fractional library routines. 39760 (line 1485) 39761 * __satfractsfqq: Fixed-point fractional library routines. 39762 (line 1484) 39763 * __satfractsfsa: Fixed-point fractional library routines. 39764 (line 1489) 39765 * __satfractsfsq: Fixed-point fractional library routines. 39766 (line 1486) 39767 * __satfractsfta: Fixed-point fractional library routines. 39768 (line 1491) 39769 * __satfractsfuda: Fixed-point fractional library routines. 39770 (line 1498) 39771 * __satfractsfudq: Fixed-point fractional library routines. 39772 (line 1495) 39773 * __satfractsfuha: Fixed-point fractional library routines. 39774 (line 1496) 39775 * __satfractsfuhq: Fixed-point fractional library routines. 39776 (line 1493) 39777 * __satfractsfuqq: Fixed-point fractional library routines. 39778 (line 1492) 39779 * __satfractsfusa: Fixed-point fractional library routines. 39780 (line 1497) 39781 * __satfractsfusq: Fixed-point fractional library routines. 39782 (line 1494) 39783 * __satfractsfuta: Fixed-point fractional library routines. 39784 (line 1499) 39785 * __satfractsida: Fixed-point fractional library routines. 39786 (line 1440) 39787 * __satfractsidq: Fixed-point fractional library routines. 39788 (line 1437) 39789 * __satfractsiha: Fixed-point fractional library routines. 39790 (line 1438) 39791 * __satfractsihq: Fixed-point fractional library routines. 39792 (line 1435) 39793 * __satfractsiqq: Fixed-point fractional library routines. 39794 (line 1434) 39795 * __satfractsisa: Fixed-point fractional library routines. 39796 (line 1439) 39797 * __satfractsisq: Fixed-point fractional library routines. 39798 (line 1436) 39799 * __satfractsita: Fixed-point fractional library routines. 39800 (line 1441) 39801 * __satfractsiuda: Fixed-point fractional library routines. 39802 (line 1448) 39803 * __satfractsiudq: Fixed-point fractional library routines. 39804 (line 1445) 39805 * __satfractsiuha: Fixed-point fractional library routines. 39806 (line 1446) 39807 * __satfractsiuhq: Fixed-point fractional library routines. 39808 (line 1443) 39809 * __satfractsiuqq: Fixed-point fractional library routines. 39810 (line 1442) 39811 * __satfractsiusa: Fixed-point fractional library routines. 39812 (line 1447) 39813 * __satfractsiusq: Fixed-point fractional library routines. 39814 (line 1444) 39815 * __satfractsiuta: Fixed-point fractional library routines. 39816 (line 1449) 39817 * __satfractsqda: Fixed-point fractional library routines. 39818 (line 1079) 39819 * __satfractsqdq2: Fixed-point fractional library routines. 39820 (line 1076) 39821 * __satfractsqha: Fixed-point fractional library routines. 39822 (line 1077) 39823 * __satfractsqhq2: Fixed-point fractional library routines. 39824 (line 1075) 39825 * __satfractsqqq2: Fixed-point fractional library routines. 39826 (line 1074) 39827 * __satfractsqsa: Fixed-point fractional library routines. 39828 (line 1078) 39829 * __satfractsqta: Fixed-point fractional library routines. 39830 (line 1080) 39831 * __satfractsquda: Fixed-point fractional library routines. 39832 (line 1090) 39833 * __satfractsqudq: Fixed-point fractional library routines. 39834 (line 1086) 39835 * __satfractsquha: Fixed-point fractional library routines. 39836 (line 1088) 39837 * __satfractsquhq: Fixed-point fractional library routines. 39838 (line 1083) 39839 * __satfractsquqq: Fixed-point fractional library routines. 39840 (line 1082) 39841 * __satfractsqusa: Fixed-point fractional library routines. 39842 (line 1089) 39843 * __satfractsqusq: Fixed-point fractional library routines. 39844 (line 1084) 39845 * __satfractsquta: Fixed-point fractional library routines. 39846 (line 1092) 39847 * __satfracttada2: Fixed-point fractional library routines. 39848 (line 1175) 39849 * __satfracttadq: Fixed-point fractional library routines. 39850 (line 1172) 39851 * __satfracttaha2: Fixed-point fractional library routines. 39852 (line 1173) 39853 * __satfracttahq: Fixed-point fractional library routines. 39854 (line 1170) 39855 * __satfracttaqq: Fixed-point fractional library routines. 39856 (line 1169) 39857 * __satfracttasa2: Fixed-point fractional library routines. 39858 (line 1174) 39859 * __satfracttasq: Fixed-point fractional library routines. 39860 (line 1171) 39861 * __satfracttauda: Fixed-point fractional library routines. 39862 (line 1187) 39863 * __satfracttaudq: Fixed-point fractional library routines. 39864 (line 1182) 39865 * __satfracttauha: Fixed-point fractional library routines. 39866 (line 1184) 39867 * __satfracttauhq: Fixed-point fractional library routines. 39868 (line 1178) 39869 * __satfracttauqq: Fixed-point fractional library routines. 39870 (line 1177) 39871 * __satfracttausa: Fixed-point fractional library routines. 39872 (line 1185) 39873 * __satfracttausq: Fixed-point fractional library routines. 39874 (line 1180) 39875 * __satfracttauta: Fixed-point fractional library routines. 39876 (line 1189) 39877 * __satfracttida: Fixed-point fractional library routines. 39878 (line 1472) 39879 * __satfracttidq: Fixed-point fractional library routines. 39880 (line 1469) 39881 * __satfracttiha: Fixed-point fractional library routines. 39882 (line 1470) 39883 * __satfracttihq: Fixed-point fractional library routines. 39884 (line 1467) 39885 * __satfracttiqq: Fixed-point fractional library routines. 39886 (line 1466) 39887 * __satfracttisa: Fixed-point fractional library routines. 39888 (line 1471) 39889 * __satfracttisq: Fixed-point fractional library routines. 39890 (line 1468) 39891 * __satfracttita: Fixed-point fractional library routines. 39892 (line 1473) 39893 * __satfracttiuda: Fixed-point fractional library routines. 39894 (line 1481) 39895 * __satfracttiudq: Fixed-point fractional library routines. 39896 (line 1478) 39897 * __satfracttiuha: Fixed-point fractional library routines. 39898 (line 1479) 39899 * __satfracttiuhq: Fixed-point fractional library routines. 39900 (line 1475) 39901 * __satfracttiuqq: Fixed-point fractional library routines. 39902 (line 1474) 39903 * __satfracttiusa: Fixed-point fractional library routines. 39904 (line 1480) 39905 * __satfracttiusq: Fixed-point fractional library routines. 39906 (line 1476) 39907 * __satfracttiuta: Fixed-point fractional library routines. 39908 (line 1483) 39909 * __satfractudada: Fixed-point fractional library routines. 39910 (line 1351) 39911 * __satfractudadq: Fixed-point fractional library routines. 39912 (line 1347) 39913 * __satfractudaha: Fixed-point fractional library routines. 39914 (line 1349) 39915 * __satfractudahq: Fixed-point fractional library routines. 39916 (line 1344) 39917 * __satfractudaqq: Fixed-point fractional library routines. 39918 (line 1343) 39919 * __satfractudasa: Fixed-point fractional library routines. 39920 (line 1350) 39921 * __satfractudasq: Fixed-point fractional library routines. 39922 (line 1345) 39923 * __satfractudata: Fixed-point fractional library routines. 39924 (line 1353) 39925 * __satfractudaudq: Fixed-point fractional library routines. 39926 (line 1361) 39927 * __satfractudauha2: Fixed-point fractional library routines. 39928 (line 1363) 39929 * __satfractudauhq: Fixed-point fractional library routines. 39930 (line 1357) 39931 * __satfractudauqq: Fixed-point fractional library routines. 39932 (line 1355) 39933 * __satfractudausa2: Fixed-point fractional library routines. 39934 (line 1365) 39935 * __satfractudausq: Fixed-point fractional library routines. 39936 (line 1359) 39937 * __satfractudauta2: Fixed-point fractional library routines. 39938 (line 1367) 39939 * __satfractudqda: Fixed-point fractional library routines. 39940 (line 1276) 39941 * __satfractudqdq: Fixed-point fractional library routines. 39942 (line 1271) 39943 * __satfractudqha: Fixed-point fractional library routines. 39944 (line 1273) 39945 * __satfractudqhq: Fixed-point fractional library routines. 39946 (line 1267) 39947 * __satfractudqqq: Fixed-point fractional library routines. 39948 (line 1266) 39949 * __satfractudqsa: Fixed-point fractional library routines. 39950 (line 1274) 39951 * __satfractudqsq: Fixed-point fractional library routines. 39952 (line 1269) 39953 * __satfractudqta: Fixed-point fractional library routines. 39954 (line 1278) 39955 * __satfractudquda: Fixed-point fractional library routines. 39956 (line 1290) 39957 * __satfractudquha: Fixed-point fractional library routines. 39958 (line 1286) 39959 * __satfractudquhq2: Fixed-point fractional library routines. 39960 (line 1282) 39961 * __satfractudquqq2: Fixed-point fractional library routines. 39962 (line 1280) 39963 * __satfractudqusa: Fixed-point fractional library routines. 39964 (line 1288) 39965 * __satfractudqusq2: Fixed-point fractional library routines. 39966 (line 1284) 39967 * __satfractudquta: Fixed-point fractional library routines. 39968 (line 1292) 39969 * __satfractuhada: Fixed-point fractional library routines. 39970 (line 1304) 39971 * __satfractuhadq: Fixed-point fractional library routines. 39972 (line 1299) 39973 * __satfractuhaha: Fixed-point fractional library routines. 39974 (line 1301) 39975 * __satfractuhahq: Fixed-point fractional library routines. 39976 (line 1295) 39977 * __satfractuhaqq: Fixed-point fractional library routines. 39978 (line 1294) 39979 * __satfractuhasa: Fixed-point fractional library routines. 39980 (line 1302) 39981 * __satfractuhasq: Fixed-point fractional library routines. 39982 (line 1297) 39983 * __satfractuhata: Fixed-point fractional library routines. 39984 (line 1306) 39985 * __satfractuhauda2: Fixed-point fractional library routines. 39986 (line 1318) 39987 * __satfractuhaudq: Fixed-point fractional library routines. 39988 (line 1314) 39989 * __satfractuhauhq: Fixed-point fractional library routines. 39990 (line 1310) 39991 * __satfractuhauqq: Fixed-point fractional library routines. 39992 (line 1308) 39993 * __satfractuhausa2: Fixed-point fractional library routines. 39994 (line 1316) 39995 * __satfractuhausq: Fixed-point fractional library routines. 39996 (line 1312) 39997 * __satfractuhauta2: Fixed-point fractional library routines. 39998 (line 1320) 39999 * __satfractuhqda: Fixed-point fractional library routines. 40000 (line 1224) 40001 * __satfractuhqdq: Fixed-point fractional library routines. 40002 (line 1221) 40003 * __satfractuhqha: Fixed-point fractional library routines. 40004 (line 1222) 40005 * __satfractuhqhq: Fixed-point fractional library routines. 40006 (line 1219) 40007 * __satfractuhqqq: Fixed-point fractional library routines. 40008 (line 1218) 40009 * __satfractuhqsa: Fixed-point fractional library routines. 40010 (line 1223) 40011 * __satfractuhqsq: Fixed-point fractional library routines. 40012 (line 1220) 40013 * __satfractuhqta: Fixed-point fractional library routines. 40014 (line 1225) 40015 * __satfractuhquda: Fixed-point fractional library routines. 40016 (line 1236) 40017 * __satfractuhqudq2: Fixed-point fractional library routines. 40018 (line 1231) 40019 * __satfractuhquha: Fixed-point fractional library routines. 40020 (line 1233) 40021 * __satfractuhquqq2: Fixed-point fractional library routines. 40022 (line 1227) 40023 * __satfractuhqusa: Fixed-point fractional library routines. 40024 (line 1234) 40025 * __satfractuhqusq2: Fixed-point fractional library routines. 40026 (line 1229) 40027 * __satfractuhquta: Fixed-point fractional library routines. 40028 (line 1238) 40029 * __satfractunsdida: Fixed-point fractional library routines. 40030 (line 1834) 40031 * __satfractunsdidq: Fixed-point fractional library routines. 40032 (line 1831) 40033 * __satfractunsdiha: Fixed-point fractional library routines. 40034 (line 1832) 40035 * __satfractunsdihq: Fixed-point fractional library routines. 40036 (line 1828) 40037 * __satfractunsdiqq: Fixed-point fractional library routines. 40038 (line 1827) 40039 * __satfractunsdisa: Fixed-point fractional library routines. 40040 (line 1833) 40041 * __satfractunsdisq: Fixed-point fractional library routines. 40042 (line 1829) 40043 * __satfractunsdita: Fixed-point fractional library routines. 40044 (line 1836) 40045 * __satfractunsdiuda: Fixed-point fractional library routines. 40046 (line 1850) 40047 * __satfractunsdiudq: Fixed-point fractional library routines. 40048 (line 1844) 40049 * __satfractunsdiuha: Fixed-point fractional library routines. 40050 (line 1846) 40051 * __satfractunsdiuhq: Fixed-point fractional library routines. 40052 (line 1840) 40053 * __satfractunsdiuqq: Fixed-point fractional library routines. 40054 (line 1838) 40055 * __satfractunsdiusa: Fixed-point fractional library routines. 40056 (line 1848) 40057 * __satfractunsdiusq: Fixed-point fractional library routines. 40058 (line 1842) 40059 * __satfractunsdiuta: Fixed-point fractional library routines. 40060 (line 1852) 40061 * __satfractunshida: Fixed-point fractional library routines. 40062 (line 1786) 40063 * __satfractunshidq: Fixed-point fractional library routines. 40064 (line 1783) 40065 * __satfractunshiha: Fixed-point fractional library routines. 40066 (line 1784) 40067 * __satfractunshihq: Fixed-point fractional library routines. 40068 (line 1780) 40069 * __satfractunshiqq: Fixed-point fractional library routines. 40070 (line 1779) 40071 * __satfractunshisa: Fixed-point fractional library routines. 40072 (line 1785) 40073 * __satfractunshisq: Fixed-point fractional library routines. 40074 (line 1781) 40075 * __satfractunshita: Fixed-point fractional library routines. 40076 (line 1788) 40077 * __satfractunshiuda: Fixed-point fractional library routines. 40078 (line 1802) 40079 * __satfractunshiudq: Fixed-point fractional library routines. 40080 (line 1796) 40081 * __satfractunshiuha: Fixed-point fractional library routines. 40082 (line 1798) 40083 * __satfractunshiuhq: Fixed-point fractional library routines. 40084 (line 1792) 40085 * __satfractunshiuqq: Fixed-point fractional library routines. 40086 (line 1790) 40087 * __satfractunshiusa: Fixed-point fractional library routines. 40088 (line 1800) 40089 * __satfractunshiusq: Fixed-point fractional library routines. 40090 (line 1794) 40091 * __satfractunshiuta: Fixed-point fractional library routines. 40092 (line 1804) 40093 * __satfractunsqida: Fixed-point fractional library routines. 40094 (line 1760) 40095 * __satfractunsqidq: Fixed-point fractional library routines. 40096 (line 1757) 40097 * __satfractunsqiha: Fixed-point fractional library routines. 40098 (line 1758) 40099 * __satfractunsqihq: Fixed-point fractional library routines. 40100 (line 1754) 40101 * __satfractunsqiqq: Fixed-point fractional library routines. 40102 (line 1753) 40103 * __satfractunsqisa: Fixed-point fractional library routines. 40104 (line 1759) 40105 * __satfractunsqisq: Fixed-point fractional library routines. 40106 (line 1755) 40107 * __satfractunsqita: Fixed-point fractional library routines. 40108 (line 1762) 40109 * __satfractunsqiuda: Fixed-point fractional library routines. 40110 (line 1776) 40111 * __satfractunsqiudq: Fixed-point fractional library routines. 40112 (line 1770) 40113 * __satfractunsqiuha: Fixed-point fractional library routines. 40114 (line 1772) 40115 * __satfractunsqiuhq: Fixed-point fractional library routines. 40116 (line 1766) 40117 * __satfractunsqiuqq: Fixed-point fractional library routines. 40118 (line 1764) 40119 * __satfractunsqiusa: Fixed-point fractional library routines. 40120 (line 1774) 40121 * __satfractunsqiusq: Fixed-point fractional library routines. 40122 (line 1768) 40123 * __satfractunsqiuta: Fixed-point fractional library routines. 40124 (line 1778) 40125 * __satfractunssida: Fixed-point fractional library routines. 40126 (line 1811) 40127 * __satfractunssidq: Fixed-point fractional library routines. 40128 (line 1808) 40129 * __satfractunssiha: Fixed-point fractional library routines. 40130 (line 1809) 40131 * __satfractunssihq: Fixed-point fractional library routines. 40132 (line 1806) 40133 * __satfractunssiqq: Fixed-point fractional library routines. 40134 (line 1805) 40135 * __satfractunssisa: Fixed-point fractional library routines. 40136 (line 1810) 40137 * __satfractunssisq: Fixed-point fractional library routines. 40138 (line 1807) 40139 * __satfractunssita: Fixed-point fractional library routines. 40140 (line 1812) 40141 * __satfractunssiuda: Fixed-point fractional library routines. 40142 (line 1824) 40143 * __satfractunssiudq: Fixed-point fractional library routines. 40144 (line 1819) 40145 * __satfractunssiuha: Fixed-point fractional library routines. 40146 (line 1821) 40147 * __satfractunssiuhq: Fixed-point fractional library routines. 40148 (line 1815) 40149 * __satfractunssiuqq: Fixed-point fractional library routines. 40150 (line 1814) 40151 * __satfractunssiusa: Fixed-point fractional library routines. 40152 (line 1822) 40153 * __satfractunssiusq: Fixed-point fractional library routines. 40154 (line 1817) 40155 * __satfractunssiuta: Fixed-point fractional library routines. 40156 (line 1826) 40157 * __satfractunstida: Fixed-point fractional library routines. 40158 (line 1864) 40159 * __satfractunstidq: Fixed-point fractional library routines. 40160 (line 1859) 40161 * __satfractunstiha: Fixed-point fractional library routines. 40162 (line 1861) 40163 * __satfractunstihq: Fixed-point fractional library routines. 40164 (line 1855) 40165 * __satfractunstiqq: Fixed-point fractional library routines. 40166 (line 1854) 40167 * __satfractunstisa: Fixed-point fractional library routines. 40168 (line 1862) 40169 * __satfractunstisq: Fixed-point fractional library routines. 40170 (line 1857) 40171 * __satfractunstita: Fixed-point fractional library routines. 40172 (line 1866) 40173 * __satfractunstiuda: Fixed-point fractional library routines. 40174 (line 1880) 40175 * __satfractunstiudq: Fixed-point fractional library routines. 40176 (line 1874) 40177 * __satfractunstiuha: Fixed-point fractional library routines. 40178 (line 1876) 40179 * __satfractunstiuhq: Fixed-point fractional library routines. 40180 (line 1870) 40181 * __satfractunstiuqq: Fixed-point fractional library routines. 40182 (line 1868) 40183 * __satfractunstiusa: Fixed-point fractional library routines. 40184 (line 1878) 40185 * __satfractunstiusq: Fixed-point fractional library routines. 40186 (line 1872) 40187 * __satfractunstiuta: Fixed-point fractional library routines. 40188 (line 1882) 40189 * __satfractuqqda: Fixed-point fractional library routines. 40190 (line 1201) 40191 * __satfractuqqdq: Fixed-point fractional library routines. 40192 (line 1196) 40193 * __satfractuqqha: Fixed-point fractional library routines. 40194 (line 1198) 40195 * __satfractuqqhq: Fixed-point fractional library routines. 40196 (line 1192) 40197 * __satfractuqqqq: Fixed-point fractional library routines. 40198 (line 1191) 40199 * __satfractuqqsa: Fixed-point fractional library routines. 40200 (line 1199) 40201 * __satfractuqqsq: Fixed-point fractional library routines. 40202 (line 1194) 40203 * __satfractuqqta: Fixed-point fractional library routines. 40204 (line 1203) 40205 * __satfractuqquda: Fixed-point fractional library routines. 40206 (line 1215) 40207 * __satfractuqqudq2: Fixed-point fractional library routines. 40208 (line 1209) 40209 * __satfractuqquha: Fixed-point fractional library routines. 40210 (line 1211) 40211 * __satfractuqquhq2: Fixed-point fractional library routines. 40212 (line 1205) 40213 * __satfractuqqusa: Fixed-point fractional library routines. 40214 (line 1213) 40215 * __satfractuqqusq2: Fixed-point fractional library routines. 40216 (line 1207) 40217 * __satfractuqquta: Fixed-point fractional library routines. 40218 (line 1217) 40219 * __satfractusada: Fixed-point fractional library routines. 40220 (line 1327) 40221 * __satfractusadq: Fixed-point fractional library routines. 40222 (line 1324) 40223 * __satfractusaha: Fixed-point fractional library routines. 40224 (line 1325) 40225 * __satfractusahq: Fixed-point fractional library routines. 40226 (line 1322) 40227 * __satfractusaqq: Fixed-point fractional library routines. 40228 (line 1321) 40229 * __satfractusasa: Fixed-point fractional library routines. 40230 (line 1326) 40231 * __satfractusasq: Fixed-point fractional library routines. 40232 (line 1323) 40233 * __satfractusata: Fixed-point fractional library routines. 40234 (line 1328) 40235 * __satfractusauda2: Fixed-point fractional library routines. 40236 (line 1339) 40237 * __satfractusaudq: Fixed-point fractional library routines. 40238 (line 1335) 40239 * __satfractusauha2: Fixed-point fractional library routines. 40240 (line 1337) 40241 * __satfractusauhq: Fixed-point fractional library routines. 40242 (line 1331) 40243 * __satfractusauqq: Fixed-point fractional library routines. 40244 (line 1330) 40245 * __satfractusausq: Fixed-point fractional library routines. 40246 (line 1333) 40247 * __satfractusauta2: Fixed-point fractional library routines. 40248 (line 1341) 40249 * __satfractusqda: Fixed-point fractional library routines. 40250 (line 1248) 40251 * __satfractusqdq: Fixed-point fractional library routines. 40252 (line 1244) 40253 * __satfractusqha: Fixed-point fractional library routines. 40254 (line 1246) 40255 * __satfractusqhq: Fixed-point fractional library routines. 40256 (line 1241) 40257 * __satfractusqqq: Fixed-point fractional library routines. 40258 (line 1240) 40259 * __satfractusqsa: Fixed-point fractional library routines. 40260 (line 1247) 40261 * __satfractusqsq: Fixed-point fractional library routines. 40262 (line 1242) 40263 * __satfractusqta: Fixed-point fractional library routines. 40264 (line 1250) 40265 * __satfractusquda: Fixed-point fractional library routines. 40266 (line 1262) 40267 * __satfractusqudq2: Fixed-point fractional library routines. 40268 (line 1256) 40269 * __satfractusquha: Fixed-point fractional library routines. 40270 (line 1258) 40271 * __satfractusquhq2: Fixed-point fractional library routines. 40272 (line 1254) 40273 * __satfractusquqq2: Fixed-point fractional library routines. 40274 (line 1252) 40275 * __satfractusqusa: Fixed-point fractional library routines. 40276 (line 1260) 40277 * __satfractusquta: Fixed-point fractional library routines. 40278 (line 1264) 40279 * __satfractutada: Fixed-point fractional library routines. 40280 (line 1379) 40281 * __satfractutadq: Fixed-point fractional library routines. 40282 (line 1374) 40283 * __satfractutaha: Fixed-point fractional library routines. 40284 (line 1376) 40285 * __satfractutahq: Fixed-point fractional library routines. 40286 (line 1370) 40287 * __satfractutaqq: Fixed-point fractional library routines. 40288 (line 1369) 40289 * __satfractutasa: Fixed-point fractional library routines. 40290 (line 1377) 40291 * __satfractutasq: Fixed-point fractional library routines. 40292 (line 1372) 40293 * __satfractutata: Fixed-point fractional library routines. 40294 (line 1381) 40295 * __satfractutauda2: Fixed-point fractional library routines. 40296 (line 1395) 40297 * __satfractutaudq: Fixed-point fractional library routines. 40298 (line 1389) 40299 * __satfractutauha2: Fixed-point fractional library routines. 40300 (line 1391) 40301 * __satfractutauhq: Fixed-point fractional library routines. 40302 (line 1385) 40303 * __satfractutauqq: Fixed-point fractional library routines. 40304 (line 1383) 40305 * __satfractutausa2: Fixed-point fractional library routines. 40306 (line 1393) 40307 * __satfractutausq: Fixed-point fractional library routines. 40308 (line 1387) 40309 * __ssaddda3: Fixed-point fractional library routines. 40310 (line 67) 40311 * __ssadddq3: Fixed-point fractional library routines. 40312 (line 63) 40313 * __ssaddha3: Fixed-point fractional library routines. 40314 (line 65) 40315 * __ssaddhq3: Fixed-point fractional library routines. 40316 (line 60) 40317 * __ssaddqq3: Fixed-point fractional library routines. 40318 (line 59) 40319 * __ssaddsa3: Fixed-point fractional library routines. 40320 (line 66) 40321 * __ssaddsq3: Fixed-point fractional library routines. 40322 (line 61) 40323 * __ssaddta3: Fixed-point fractional library routines. 40324 (line 69) 40325 * __ssashlda3: Fixed-point fractional library routines. 40326 (line 402) 40327 * __ssashldq3: Fixed-point fractional library routines. 40328 (line 399) 40329 * __ssashlha3: Fixed-point fractional library routines. 40330 (line 400) 40331 * __ssashlhq3: Fixed-point fractional library routines. 40332 (line 396) 40333 * __ssashlsa3: Fixed-point fractional library routines. 40334 (line 401) 40335 * __ssashlsq3: Fixed-point fractional library routines. 40336 (line 397) 40337 * __ssashlta3: Fixed-point fractional library routines. 40338 (line 404) 40339 * __ssdivda3: Fixed-point fractional library routines. 40340 (line 261) 40341 * __ssdivdq3: Fixed-point fractional library routines. 40342 (line 257) 40343 * __ssdivha3: Fixed-point fractional library routines. 40344 (line 259) 40345 * __ssdivhq3: Fixed-point fractional library routines. 40346 (line 254) 40347 * __ssdivqq3: Fixed-point fractional library routines. 40348 (line 253) 40349 * __ssdivsa3: Fixed-point fractional library routines. 40350 (line 260) 40351 * __ssdivsq3: Fixed-point fractional library routines. 40352 (line 255) 40353 * __ssdivta3: Fixed-point fractional library routines. 40354 (line 263) 40355 * __ssmulda3: Fixed-point fractional library routines. 40356 (line 193) 40357 * __ssmuldq3: Fixed-point fractional library routines. 40358 (line 189) 40359 * __ssmulha3: Fixed-point fractional library routines. 40360 (line 191) 40361 * __ssmulhq3: Fixed-point fractional library routines. 40362 (line 186) 40363 * __ssmulqq3: Fixed-point fractional library routines. 40364 (line 185) 40365 * __ssmulsa3: Fixed-point fractional library routines. 40366 (line 192) 40367 * __ssmulsq3: Fixed-point fractional library routines. 40368 (line 187) 40369 * __ssmulta3: Fixed-point fractional library routines. 40370 (line 195) 40371 * __ssnegda2: Fixed-point fractional library routines. 40372 (line 316) 40373 * __ssnegdq2: Fixed-point fractional library routines. 40374 (line 313) 40375 * __ssnegha2: Fixed-point fractional library routines. 40376 (line 314) 40377 * __ssneghq2: Fixed-point fractional library routines. 40378 (line 311) 40379 * __ssnegqq2: Fixed-point fractional library routines. 40380 (line 310) 40381 * __ssnegsa2: Fixed-point fractional library routines. 40382 (line 315) 40383 * __ssnegsq2: Fixed-point fractional library routines. 40384 (line 312) 40385 * __ssnegta2: Fixed-point fractional library routines. 40386 (line 317) 40387 * __sssubda3: Fixed-point fractional library routines. 40388 (line 129) 40389 * __sssubdq3: Fixed-point fractional library routines. 40390 (line 125) 40391 * __sssubha3: Fixed-point fractional library routines. 40392 (line 127) 40393 * __sssubhq3: Fixed-point fractional library routines. 40394 (line 122) 40395 * __sssubqq3: Fixed-point fractional library routines. 40396 (line 121) 40397 * __sssubsa3: Fixed-point fractional library routines. 40398 (line 128) 40399 * __sssubsq3: Fixed-point fractional library routines. 40400 (line 123) 40401 * __sssubta3: Fixed-point fractional library routines. 40402 (line 131) 40403 * __subda3: Fixed-point fractional library routines. 40404 (line 107) 40405 * __subdf3: Soft float library routines. 40406 (line 31) 40407 * __subdq3: Fixed-point fractional library routines. 40408 (line 95) 40409 * __subha3: Fixed-point fractional library routines. 40410 (line 105) 40411 * __subhq3: Fixed-point fractional library routines. 40412 (line 92) 40413 * __subqq3: Fixed-point fractional library routines. 40414 (line 91) 40415 * __subsa3: Fixed-point fractional library routines. 40416 (line 106) 40417 * __subsf3: Soft float library routines. 40418 (line 30) 40419 * __subsq3: Fixed-point fractional library routines. 40420 (line 93) 40421 * __subta3: Fixed-point fractional library routines. 40422 (line 109) 40423 * __subtf3: Soft float library routines. 40424 (line 33) 40425 * __subuda3: Fixed-point fractional library routines. 40426 (line 115) 40427 * __subudq3: Fixed-point fractional library routines. 40428 (line 103) 40429 * __subuha3: Fixed-point fractional library routines. 40430 (line 111) 40431 * __subuhq3: Fixed-point fractional library routines. 40432 (line 99) 40433 * __subuqq3: Fixed-point fractional library routines. 40434 (line 97) 40435 * __subusa3: Fixed-point fractional library routines. 40436 (line 113) 40437 * __subusq3: Fixed-point fractional library routines. 40438 (line 101) 40439 * __subuta3: Fixed-point fractional library routines. 40440 (line 117) 40441 * __subvdi3: Integer library routines. 40442 (line 123) 40443 * __subvsi3: Integer library routines. 40444 (line 122) 40445 * __subxf3: Soft float library routines. 40446 (line 35) 40447 * __truncdfsf2: Soft float library routines. 40448 (line 76) 40449 * __trunctfdf2: Soft float library routines. 40450 (line 73) 40451 * __trunctfsf2: Soft float library routines. 40452 (line 75) 40453 * __truncxfdf2: Soft float library routines. 40454 (line 72) 40455 * __truncxfsf2: Soft float library routines. 40456 (line 74) 40457 * __ucmpdi2: Integer library routines. 40458 (line 93) 40459 * __ucmpti2: Integer library routines. 40460 (line 95) 40461 * __udivdi3: Integer library routines. 40462 (line 54) 40463 * __udivmoddi3: Integer library routines. 40464 (line 61) 40465 * __udivsi3: Integer library routines. 40466 (line 52) 40467 * __udivti3: Integer library routines. 40468 (line 63) 40469 * __udivuda3: Fixed-point fractional library routines. 40470 (line 246) 40471 * __udivudq3: Fixed-point fractional library routines. 40472 (line 240) 40473 * __udivuha3: Fixed-point fractional library routines. 40474 (line 242) 40475 * __udivuhq3: Fixed-point fractional library routines. 40476 (line 236) 40477 * __udivuqq3: Fixed-point fractional library routines. 40478 (line 234) 40479 * __udivusa3: Fixed-point fractional library routines. 40480 (line 244) 40481 * __udivusq3: Fixed-point fractional library routines. 40482 (line 238) 40483 * __udivuta3: Fixed-point fractional library routines. 40484 (line 248) 40485 * __umoddi3: Integer library routines. 40486 (line 71) 40487 * __umodsi3: Integer library routines. 40488 (line 69) 40489 * __umodti3: Integer library routines. 40490 (line 73) 40491 * __unorddf2: Soft float library routines. 40492 (line 173) 40493 * __unordsf2: Soft float library routines. 40494 (line 172) 40495 * __unordtf2: Soft float library routines. 40496 (line 174) 40497 * __usadduda3: Fixed-point fractional library routines. 40498 (line 85) 40499 * __usaddudq3: Fixed-point fractional library routines. 40500 (line 79) 40501 * __usadduha3: Fixed-point fractional library routines. 40502 (line 81) 40503 * __usadduhq3: Fixed-point fractional library routines. 40504 (line 75) 40505 * __usadduqq3: Fixed-point fractional library routines. 40506 (line 73) 40507 * __usaddusa3: Fixed-point fractional library routines. 40508 (line 83) 40509 * __usaddusq3: Fixed-point fractional library routines. 40510 (line 77) 40511 * __usadduta3: Fixed-point fractional library routines. 40512 (line 87) 40513 * __usashluda3: Fixed-point fractional library routines. 40514 (line 421) 40515 * __usashludq3: Fixed-point fractional library routines. 40516 (line 415) 40517 * __usashluha3: Fixed-point fractional library routines. 40518 (line 417) 40519 * __usashluhq3: Fixed-point fractional library routines. 40520 (line 411) 40521 * __usashluqq3: Fixed-point fractional library routines. 40522 (line 409) 40523 * __usashlusa3: Fixed-point fractional library routines. 40524 (line 419) 40525 * __usashlusq3: Fixed-point fractional library routines. 40526 (line 413) 40527 * __usashluta3: Fixed-point fractional library routines. 40528 (line 423) 40529 * __usdivuda3: Fixed-point fractional library routines. 40530 (line 280) 40531 * __usdivudq3: Fixed-point fractional library routines. 40532 (line 274) 40533 * __usdivuha3: Fixed-point fractional library routines. 40534 (line 276) 40535 * __usdivuhq3: Fixed-point fractional library routines. 40536 (line 270) 40537 * __usdivuqq3: Fixed-point fractional library routines. 40538 (line 268) 40539 * __usdivusa3: Fixed-point fractional library routines. 40540 (line 278) 40541 * __usdivusq3: Fixed-point fractional library routines. 40542 (line 272) 40543 * __usdivuta3: Fixed-point fractional library routines. 40544 (line 282) 40545 * __usmuluda3: Fixed-point fractional library routines. 40546 (line 212) 40547 * __usmuludq3: Fixed-point fractional library routines. 40548 (line 206) 40549 * __usmuluha3: Fixed-point fractional library routines. 40550 (line 208) 40551 * __usmuluhq3: Fixed-point fractional library routines. 40552 (line 202) 40553 * __usmuluqq3: Fixed-point fractional library routines. 40554 (line 200) 40555 * __usmulusa3: Fixed-point fractional library routines. 40556 (line 210) 40557 * __usmulusq3: Fixed-point fractional library routines. 40558 (line 204) 40559 * __usmuluta3: Fixed-point fractional library routines. 40560 (line 214) 40561 * __usneguda2: Fixed-point fractional library routines. 40562 (line 331) 40563 * __usnegudq2: Fixed-point fractional library routines. 40564 (line 326) 40565 * __usneguha2: Fixed-point fractional library routines. 40566 (line 328) 40567 * __usneguhq2: Fixed-point fractional library routines. 40568 (line 322) 40569 * __usneguqq2: Fixed-point fractional library routines. 40570 (line 321) 40571 * __usnegusa2: Fixed-point fractional library routines. 40572 (line 329) 40573 * __usnegusq2: Fixed-point fractional library routines. 40574 (line 324) 40575 * __usneguta2: Fixed-point fractional library routines. 40576 (line 333) 40577 * __ussubuda3: Fixed-point fractional library routines. 40578 (line 148) 40579 * __ussubudq3: Fixed-point fractional library routines. 40580 (line 142) 40581 * __ussubuha3: Fixed-point fractional library routines. 40582 (line 144) 40583 * __ussubuhq3: Fixed-point fractional library routines. 40584 (line 138) 40585 * __ussubuqq3: Fixed-point fractional library routines. 40586 (line 136) 40587 * __ussubusa3: Fixed-point fractional library routines. 40588 (line 146) 40589 * __ussubusq3: Fixed-point fractional library routines. 40590 (line 140) 40591 * __ussubuta3: Fixed-point fractional library routines. 40592 (line 150) 40593 * abort: Portability. (line 21) 40594 * abs: Arithmetic. (line 195) 40595 * abs and attributes: Expressions. (line 64) 40596 * ABS_EXPR: Expression trees. (line 6) 40597 * absence_set: Processor pipeline description. 40598 (line 215) 40599 * absM2 instruction pattern: Standard Names. (line 452) 40600 * absolute value: Arithmetic. (line 195) 40601 * access to operands: Accessors. (line 6) 40602 * access to special operands: Special Accessors. (line 6) 40603 * accessors: Accessors. (line 6) 40604 * ACCUM_TYPE_SIZE: Type Layout. (line 88) 40605 * ACCUMULATE_OUTGOING_ARGS: Stack Arguments. (line 46) 40606 * ACCUMULATE_OUTGOING_ARGS and stack frames: Function Entry. (line 135) 40607 * ADA_LONG_TYPE_SIZE: Type Layout. (line 26) 40608 * Adding a new GIMPLE statement code: Adding a new GIMPLE statement code. 40609 (line 6) 40610 * ADDITIONAL_REGISTER_NAMES: Instruction Output. (line 15) 40611 * addM3 instruction pattern: Standard Names. (line 216) 40612 * addMODEcc instruction pattern: Standard Names. (line 904) 40613 * addr_diff_vec: Side Effects. (line 302) 40614 * addr_diff_vec, length of: Insn Lengths. (line 26) 40615 * ADDR_EXPR: Expression trees. (line 6) 40616 * addr_vec: Side Effects. (line 297) 40617 * addr_vec, length of: Insn Lengths. (line 26) 40618 * address constraints: Simple Constraints. (line 154) 40619 * address_operand <1>: Machine-Independent Predicates. 40620 (line 63) 40621 * address_operand: Simple Constraints. (line 158) 40622 * addressing modes: Addressing Modes. (line 6) 40623 * ADJUST_FIELD_ALIGN: Storage Layout. (line 201) 40624 * ADJUST_INSN_LENGTH: Insn Lengths. (line 35) 40625 * AGGR_INIT_EXPR: Expression trees. (line 6) 40626 * aggregates as return values: Aggregate Return. (line 6) 40627 * alias: Alias analysis. (line 6) 40628 * ALL_COP_ADDITIONAL_REGISTER_NAMES: MIPS Coprocessors. (line 32) 40629 * ALL_REGS: Register Classes. (line 17) 40630 * allocate_stack instruction pattern: Standard Names. (line 1227) 40631 * alternate entry points: Insns. (line 140) 40632 * anchored addresses: Anchored Addresses. (line 6) 40633 * and: Arithmetic. (line 153) 40634 * and and attributes: Expressions. (line 50) 40635 * and, canonicalization of: Insn Canonicalizations. 40636 (line 57) 40637 * andM3 instruction pattern: Standard Names. (line 222) 40638 * annotations: Annotations. (line 6) 40639 * APPLY_RESULT_SIZE: Scalar Return. (line 95) 40640 * ARG_POINTER_CFA_OFFSET: Frame Layout. (line 194) 40641 * ARG_POINTER_REGNUM: Frame Registers. (line 41) 40642 * ARG_POINTER_REGNUM and virtual registers: Regs and Memory. (line 65) 40643 * arg_pointer_rtx: Frame Registers. (line 85) 40644 * ARGS_GROW_DOWNWARD: Frame Layout. (line 35) 40645 * argument passing: Interface. (line 36) 40646 * arguments in registers: Register Arguments. (line 6) 40647 * arguments on stack: Stack Arguments. (line 6) 40648 * arithmetic library: Soft float library routines. 40649 (line 6) 40650 * arithmetic shift: Arithmetic. (line 168) 40651 * arithmetic shift with signed saturation: Arithmetic. (line 168) 40652 * arithmetic shift with unsigned saturation: Arithmetic. (line 168) 40653 * arithmetic, in RTL: Arithmetic. (line 6) 40654 * ARITHMETIC_TYPE_P: Types. (line 76) 40655 * array: Types. (line 6) 40656 * ARRAY_RANGE_REF: Expression trees. (line 6) 40657 * ARRAY_REF: Expression trees. (line 6) 40658 * ARRAY_TYPE: Types. (line 6) 40659 * AS_NEEDS_DASH_FOR_PIPED_INPUT: Driver. (line 151) 40660 * ashift: Arithmetic. (line 168) 40661 * ashift and attributes: Expressions. (line 64) 40662 * ashiftrt: Arithmetic. (line 185) 40663 * ashiftrt and attributes: Expressions. (line 64) 40664 * ashlM3 instruction pattern: Standard Names. (line 431) 40665 * ashrM3 instruction pattern: Standard Names. (line 441) 40666 * ASM_APP_OFF: File Framework. (line 61) 40667 * ASM_APP_ON: File Framework. (line 54) 40668 * ASM_COMMENT_START: File Framework. (line 49) 40669 * ASM_DECLARE_CLASS_REFERENCE: Label Output. (line 436) 40670 * ASM_DECLARE_CONSTANT_NAME: Label Output. (line 128) 40671 * ASM_DECLARE_FUNCTION_NAME: Label Output. (line 87) 40672 * ASM_DECLARE_FUNCTION_SIZE: Label Output. (line 101) 40673 * ASM_DECLARE_OBJECT_NAME: Label Output. (line 114) 40674 * ASM_DECLARE_REGISTER_GLOBAL: Label Output. (line 143) 40675 * ASM_DECLARE_UNRESOLVED_REFERENCE: Label Output. (line 442) 40676 * ASM_FINAL_SPEC: Driver. (line 144) 40677 * ASM_FINISH_DECLARE_OBJECT: Label Output. (line 151) 40678 * ASM_FORMAT_PRIVATE_NAME: Label Output. (line 354) 40679 * asm_fprintf: Instruction Output. (line 123) 40680 * ASM_FPRINTF_EXTENSIONS: Instruction Output. (line 134) 40681 * ASM_GENERATE_INTERNAL_LABEL: Label Output. (line 338) 40682 * asm_input: Side Effects. (line 284) 40683 * asm_input and /v: Flags. (line 94) 40684 * ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX: Exception Handling. (line 82) 40685 * ASM_NO_SKIP_IN_TEXT: Alignment Output. (line 72) 40686 * asm_noperands: Insns. (line 266) 40687 * asm_operands and /v: Flags. (line 94) 40688 * asm_operands, RTL sharing: Sharing. (line 45) 40689 * asm_operands, usage: Assembler. (line 6) 40690 * ASM_OUTPUT_ADDR_DIFF_ELT: Dispatch Tables. (line 9) 40691 * ASM_OUTPUT_ADDR_VEC_ELT: Dispatch Tables. (line 26) 40692 * ASM_OUTPUT_ALIGN: Alignment Output. (line 79) 40693 * ASM_OUTPUT_ALIGN_WITH_NOP: Alignment Output. (line 84) 40694 * ASM_OUTPUT_ALIGNED_BSS: Uninitialized Data. (line 64) 40695 * ASM_OUTPUT_ALIGNED_COMMON: Uninitialized Data. (line 23) 40696 * ASM_OUTPUT_ALIGNED_DECL_COMMON: Uninitialized Data. (line 31) 40697 * ASM_OUTPUT_ALIGNED_DECL_LOCAL: Uninitialized Data. (line 95) 40698 * ASM_OUTPUT_ALIGNED_LOCAL: Uninitialized Data. (line 87) 40699 * ASM_OUTPUT_ASCII: Data Output. (line 50) 40700 * ASM_OUTPUT_BSS: Uninitialized Data. (line 39) 40701 * ASM_OUTPUT_CASE_END: Dispatch Tables. (line 51) 40702 * ASM_OUTPUT_CASE_LABEL: Dispatch Tables. (line 38) 40703 * ASM_OUTPUT_COMMON: Uninitialized Data. (line 10) 40704 * ASM_OUTPUT_DEBUG_LABEL: Label Output. (line 326) 40705 * ASM_OUTPUT_DEF: Label Output. (line 375) 40706 * ASM_OUTPUT_DEF_FROM_DECLS: Label Output. (line 383) 40707 * ASM_OUTPUT_DWARF_DELTA: SDB and DWARF. (line 42) 40708 * ASM_OUTPUT_DWARF_OFFSET: SDB and DWARF. (line 46) 40709 * ASM_OUTPUT_DWARF_PCREL: SDB and DWARF. (line 52) 40710 * ASM_OUTPUT_EXTERNAL: Label Output. (line 264) 40711 * ASM_OUTPUT_FDESC: Data Output. (line 59) 40712 * ASM_OUTPUT_IDENT: File Framework. (line 83) 40713 * ASM_OUTPUT_INTERNAL_LABEL: Label Output. (line 17) 40714 * ASM_OUTPUT_LABEL: Label Output. (line 9) 40715 * ASM_OUTPUT_LABEL_REF: Label Output. (line 299) 40716 * ASM_OUTPUT_LABELREF: Label Output. (line 285) 40717 * ASM_OUTPUT_LOCAL: Uninitialized Data. (line 74) 40718 * ASM_OUTPUT_MAX_SKIP_ALIGN: Alignment Output. (line 88) 40719 * ASM_OUTPUT_MEASURED_SIZE: Label Output. (line 41) 40720 * ASM_OUTPUT_OPCODE: Instruction Output. (line 21) 40721 * ASM_OUTPUT_POOL_EPILOGUE: Data Output. (line 109) 40722 * ASM_OUTPUT_POOL_PROLOGUE: Data Output. (line 72) 40723 * ASM_OUTPUT_REG_POP: Instruction Output. (line 178) 40724 * ASM_OUTPUT_REG_PUSH: Instruction Output. (line 173) 40725 * ASM_OUTPUT_SIZE_DIRECTIVE: Label Output. (line 35) 40726 * ASM_OUTPUT_SKIP: Alignment Output. (line 66) 40727 * ASM_OUTPUT_SOURCE_FILENAME: File Framework. (line 68) 40728 * ASM_OUTPUT_SPECIAL_POOL_ENTRY: Data Output. (line 84) 40729 * ASM_OUTPUT_SYMBOL_REF: Label Output. (line 292) 40730 * ASM_OUTPUT_TYPE_DIRECTIVE: Label Output. (line 77) 40731 * ASM_OUTPUT_WEAK_ALIAS: Label Output. (line 401) 40732 * ASM_OUTPUT_WEAKREF: Label Output. (line 203) 40733 * ASM_PREFERRED_EH_DATA_FORMAT: Exception Handling. (line 67) 40734 * ASM_SPEC: Driver. (line 136) 40735 * ASM_STABD_OP: DBX Options. (line 36) 40736 * ASM_STABN_OP: DBX Options. (line 43) 40737 * ASM_STABS_OP: DBX Options. (line 29) 40738 * ASM_WEAKEN_DECL: Label Output. (line 195) 40739 * ASM_WEAKEN_LABEL: Label Output. (line 182) 40740 * assemble_name: Label Output. (line 8) 40741 * assemble_name_raw: Label Output. (line 16) 40742 * assembler format: File Framework. (line 6) 40743 * assembler instructions in RTL: Assembler. (line 6) 40744 * ASSEMBLER_DIALECT: Instruction Output. (line 146) 40745 * assigning attribute values to insns: Tagging Insns. (line 6) 40746 * assignment operator: Function Basics. (line 6) 40747 * asterisk in template: Output Statement. (line 29) 40748 * atan2M3 instruction pattern: Standard Names. (line 522) 40749 * attr <1>: Tagging Insns. (line 54) 40750 * attr: Expressions. (line 154) 40751 * attr_flag: Expressions. (line 119) 40752 * attribute expressions: Expressions. (line 6) 40753 * attribute specifications: Attr Example. (line 6) 40754 * attribute specifications example: Attr Example. (line 6) 40755 * ATTRIBUTE_ALIGNED_VALUE: Storage Layout. (line 183) 40756 * attributes: Attributes. (line 6) 40757 * attributes, defining: Defining Attributes. 40758 (line 6) 40759 * attributes, target-specific: Target Attributes. (line 6) 40760 * autoincrement addressing, availability: Portability. (line 21) 40761 * autoincrement/decrement addressing: Simple Constraints. (line 30) 40762 * automata_option: Processor pipeline description. 40763 (line 296) 40764 * automaton based pipeline description: Processor pipeline description. 40765 (line 49) 40766 * automaton based scheduler: Processor pipeline description. 40767 (line 6) 40768 * AVOID_CCMODE_COPIES: Values in Registers. 40769 (line 153) 40770 * backslash: Output Template. (line 46) 40771 * barrier: Insns. (line 160) 40772 * barrier and /f: Flags. (line 125) 40773 * barrier and /v: Flags. (line 44) 40774 * BASE_REG_CLASS: Register Classes. (line 107) 40775 * basic block: Basic Blocks. (line 6) 40776 * basic-block.h: Control Flow. (line 6) 40777 * BASIC_BLOCK: Basic Blocks. (line 19) 40778 * basic_block: Basic Blocks. (line 6) 40779 * BB_HEAD, BB_END: Maintaining the CFG. 40780 (line 88) 40781 * bb_seq: GIMPLE sequences. (line 73) 40782 * bCOND instruction pattern: Standard Names. (line 941) 40783 * BIGGEST_ALIGNMENT: Storage Layout. (line 173) 40784 * BIGGEST_FIELD_ALIGNMENT: Storage Layout. (line 194) 40785 * BImode: Machine Modes. (line 22) 40786 * BIND_EXPR: Expression trees. (line 6) 40787 * BINFO_TYPE: Classes. (line 6) 40788 * bit-fields: Bit-Fields. (line 6) 40789 * BIT_AND_EXPR: Expression trees. (line 6) 40790 * BIT_IOR_EXPR: Expression trees. (line 6) 40791 * BIT_NOT_EXPR: Expression trees. (line 6) 40792 * BIT_XOR_EXPR: Expression trees. (line 6) 40793 * BITFIELD_NBYTES_LIMITED: Storage Layout. (line 382) 40794 * BITS_BIG_ENDIAN: Storage Layout. (line 12) 40795 * BITS_BIG_ENDIAN, effect on sign_extract: Bit-Fields. (line 8) 40796 * BITS_PER_UNIT: Storage Layout. (line 52) 40797 * BITS_PER_WORD: Storage Layout. (line 57) 40798 * bitwise complement: Arithmetic. (line 149) 40799 * bitwise exclusive-or: Arithmetic. (line 163) 40800 * bitwise inclusive-or: Arithmetic. (line 158) 40801 * bitwise logical-and: Arithmetic. (line 153) 40802 * BLKmode: Machine Modes. (line 183) 40803 * BLKmode, and function return values: Calls. (line 23) 40804 * block statement iterators <1>: Basic Blocks. (line 68) 40805 * block statement iterators: Maintaining the CFG. 40806 (line 45) 40807 * BLOCK_FOR_INSN, bb_for_stmt: Maintaining the CFG. 40808 (line 40) 40809 * BLOCK_REG_PADDING: Register Arguments. (line 229) 40810 * blockage instruction pattern: Standard Names. (line 1408) 40811 * Blocks: Blocks. (line 6) 40812 * bool <1>: Sections. (line 280) 40813 * bool <2>: Exception Region Output. 40814 (line 60) 40815 * bool: Sections. (line 293) 40816 * BOOL_TYPE_SIZE: Type Layout. (line 44) 40817 * BOOLEAN_TYPE: Types. (line 6) 40818 * branch prediction: Profile information. 40819 (line 24) 40820 * BRANCH_COST: Costs. (line 52) 40821 * break_out_memory_refs: Addressing Modes. (line 130) 40822 * BREAK_STMT: Function Bodies. (line 6) 40823 * bsi_commit_edge_inserts: Maintaining the CFG. 40824 (line 118) 40825 * bsi_end_p: Maintaining the CFG. 40826 (line 60) 40827 * bsi_insert_after: Maintaining the CFG. 40828 (line 72) 40829 * bsi_insert_before: Maintaining the CFG. 40830 (line 78) 40831 * bsi_insert_on_edge: Maintaining the CFG. 40832 (line 118) 40833 * bsi_last: Maintaining the CFG. 40834 (line 56) 40835 * bsi_next: Maintaining the CFG. 40836 (line 64) 40837 * bsi_prev: Maintaining the CFG. 40838 (line 68) 40839 * bsi_remove: Maintaining the CFG. 40840 (line 84) 40841 * bsi_start: Maintaining the CFG. 40842 (line 52) 40843 * BSS_SECTION_ASM_OP: Sections. (line 68) 40844 * bswap: Arithmetic. (line 232) 40845 * btruncM2 instruction pattern: Standard Names. (line 540) 40846 * builtin_longjmp instruction pattern: Standard Names. (line 1313) 40847 * builtin_setjmp_receiver instruction pattern: Standard Names. 40848 (line 1303) 40849 * builtin_setjmp_setup instruction pattern: Standard Names. (line 1292) 40850 * byte_mode: Machine Modes. (line 336) 40851 * BYTES_BIG_ENDIAN: Storage Layout. (line 24) 40852 * BYTES_BIG_ENDIAN, effect on subreg: Regs and Memory. (line 221) 40853 * C statements for assembler output: Output Statement. (line 6) 40854 * C/C++ Internal Representation: Trees. (line 6) 40855 * C99 math functions, implicit usage: Library Calls. (line 76) 40856 * C_COMMON_OVERRIDE_OPTIONS: Run-time Target. (line 114) 40857 * c_register_pragma: Misc. (line 404) 40858 * c_register_pragma_with_expansion: Misc. (line 406) 40859 * call <1>: Side Effects. (line 86) 40860 * call: Flags. (line 234) 40861 * call instruction pattern: Standard Names. (line 974) 40862 * call usage: Calls. (line 10) 40863 * call, in call_insn: Flags. (line 33) 40864 * call, in mem: Flags. (line 99) 40865 * call-clobbered register: Register Basics. (line 46) 40866 * call-saved register: Register Basics. (line 46) 40867 * call-used register: Register Basics. (line 46) 40868 * CALL_EXPR: Expression trees. (line 6) 40869 * call_insn: Insns. (line 95) 40870 * call_insn and /c: Flags. (line 33) 40871 * call_insn and /f: Flags. (line 125) 40872 * call_insn and /i: Flags. (line 24) 40873 * call_insn and /j: Flags. (line 179) 40874 * call_insn and /s: Flags. (line 166) 40875 * call_insn and /u: Flags. (line 19) 40876 * call_insn and /u or /i: Flags. (line 29) 40877 * call_insn and /v: Flags. (line 44) 40878 * CALL_INSN_FUNCTION_USAGE: Insns. (line 101) 40879 * call_pop instruction pattern: Standard Names. (line 1002) 40880 * CALL_POPS_ARGS: Stack Arguments. (line 130) 40881 * CALL_REALLY_USED_REGISTERS: Register Basics. (line 46) 40882 * CALL_USED_REGISTERS: Register Basics. (line 35) 40883 * call_used_regs: Register Basics. (line 59) 40884 * call_value instruction pattern: Standard Names. (line 994) 40885 * call_value_pop instruction pattern: Standard Names. (line 1002) 40886 * CALLER_SAVE_PROFITABLE: Caller Saves. (line 11) 40887 * calling conventions: Stack and Calling. (line 6) 40888 * calling functions in RTL: Calls. (line 6) 40889 * can_create_pseudo_p: Standard Names. (line 75) 40890 * CAN_DEBUG_WITHOUT_FP: Run-time Target. (line 146) 40891 * CAN_ELIMINATE: Elimination. (line 71) 40892 * can_fallthru: Basic Blocks. (line 57) 40893 * canadian: Configure Terms. (line 6) 40894 * CANNOT_CHANGE_MODE_CLASS: Register Classes. (line 481) 40895 * CANNOT_CHANGE_MODE_CLASS and subreg semantics: Regs and Memory. 40896 (line 280) 40897 * canonicalization of instructions: Insn Canonicalizations. 40898 (line 6) 40899 * CANONICALIZE_COMPARISON: Condition Code. (line 84) 40900 * canonicalize_funcptr_for_compare instruction pattern: Standard Names. 40901 (line 1158) 40902 * CASE_USE_BIT_TESTS: Misc. (line 54) 40903 * CASE_VALUES_THRESHOLD: Misc. (line 47) 40904 * CASE_VECTOR_MODE: Misc. (line 27) 40905 * CASE_VECTOR_PC_RELATIVE: Misc. (line 40) 40906 * CASE_VECTOR_SHORTEN_MODE: Misc. (line 31) 40907 * casesi instruction pattern: Standard Names. (line 1082) 40908 * cbranchMODE4 instruction pattern: Standard Names. (line 963) 40909 * cc0: Regs and Memory. (line 307) 40910 * cc0, RTL sharing: Sharing. (line 27) 40911 * cc0_rtx: Regs and Memory. (line 333) 40912 * CC1_SPEC: Driver. (line 118) 40913 * CC1PLUS_SPEC: Driver. (line 126) 40914 * cc_status: Condition Code. (line 8) 40915 * CC_STATUS_MDEP: Condition Code. (line 19) 40916 * CC_STATUS_MDEP_INIT: Condition Code. (line 25) 40917 * CCmode: Machine Modes. (line 176) 40918 * CDImode: Machine Modes. (line 202) 40919 * CEIL_DIV_EXPR: Expression trees. (line 6) 40920 * CEIL_MOD_EXPR: Expression trees. (line 6) 40921 * ceilM2 instruction pattern: Standard Names. (line 556) 40922 * CFA_FRAME_BASE_OFFSET: Frame Layout. (line 226) 40923 * CFG, Control Flow Graph: Control Flow. (line 6) 40924 * cfghooks.h: Maintaining the CFG. 40925 (line 6) 40926 * cgraph_finalize_function: Parsing pass. (line 52) 40927 * chain_circular: GTY Options. (line 196) 40928 * chain_next: GTY Options. (line 196) 40929 * chain_prev: GTY Options. (line 196) 40930 * change_address: Standard Names. (line 47) 40931 * CHANGE_DYNAMIC_TYPE_EXPR: Expression trees. (line 6) 40932 * char <1>: Sections. (line 272) 40933 * char <2>: PCH Target. (line 12) 40934 * char <3>: Misc. (line 693) 40935 * char <4>: GIMPLE_ASM. (line 53) 40936 * char <5>: Misc. (line 908) 40937 * char: PCH Target. (line 27) 40938 * CHAR_TYPE_SIZE: Type Layout. (line 39) 40939 * check_stack instruction pattern: Standard Names. (line 1245) 40940 * CHImode: Machine Modes. (line 202) 40941 * class: Classes. (line 6) 40942 * class definitions, register: Register Classes. (line 6) 40943 * class preference constraints: Class Preferences. (line 6) 40944 * CLASS_LIKELY_SPILLED_P: Register Classes. (line 452) 40945 * CLASS_MAX_NREGS: Register Classes. (line 469) 40946 * CLASS_TYPE_P: Types. (line 80) 40947 * classes of RTX codes: RTL Classes. (line 6) 40948 * CLASSTYPE_DECLARED_CLASS: Classes. (line 6) 40949 * CLASSTYPE_HAS_MUTABLE: Classes. (line 80) 40950 * CLASSTYPE_NON_POD_P: Classes. (line 85) 40951 * CLEANUP_DECL: Function Bodies. (line 6) 40952 * CLEANUP_EXPR: Function Bodies. (line 6) 40953 * CLEANUP_POINT_EXPR: Expression trees. (line 6) 40954 * CLEANUP_STMT: Function Bodies. (line 6) 40955 * Cleanups: Cleanups. (line 6) 40956 * CLEAR_BY_PIECES_P: Costs. (line 130) 40957 * clear_cache instruction pattern: Standard Names. (line 1555) 40958 * CLEAR_INSN_CACHE: Trampolines. (line 100) 40959 * CLEAR_RATIO: Costs. (line 121) 40960 * clobber: Side Effects. (line 100) 40961 * clz: Arithmetic. (line 208) 40962 * CLZ_DEFINED_VALUE_AT_ZERO: Misc. (line 319) 40963 * clzM2 instruction pattern: Standard Names. (line 621) 40964 * cmpM instruction pattern: Standard Names. (line 654) 40965 * cmpmemM instruction pattern: Standard Names. (line 769) 40966 * cmpstrM instruction pattern: Standard Names. (line 750) 40967 * cmpstrnM instruction pattern: Standard Names. (line 738) 40968 * code generation RTL sequences: Expander Definitions. 40969 (line 6) 40970 * code iterators in .md files: Code Iterators. (line 6) 40971 * code_label: Insns. (line 119) 40972 * code_label and /i: Flags. (line 59) 40973 * code_label and /v: Flags. (line 44) 40974 * CODE_LABEL_NUMBER: Insns. (line 119) 40975 * codes, RTL expression: RTL Objects. (line 47) 40976 * COImode: Machine Modes. (line 202) 40977 * COLLECT2_HOST_INITIALIZATION: Host Misc. (line 32) 40978 * COLLECT_EXPORT_LIST: Misc. (line 775) 40979 * COLLECT_SHARED_FINI_FUNC: Macros for Initialization. 40980 (line 44) 40981 * COLLECT_SHARED_INIT_FUNC: Macros for Initialization. 40982 (line 33) 40983 * commit_edge_insertions: Maintaining the CFG. 40984 (line 118) 40985 * compare: Arithmetic. (line 43) 40986 * compare, canonicalization of: Insn Canonicalizations. 40987 (line 37) 40988 * comparison_operator: Machine-Independent Predicates. 40989 (line 111) 40990 * compiler passes and files: Passes. (line 6) 40991 * complement, bitwise: Arithmetic. (line 149) 40992 * COMPLEX_CST: Expression trees. (line 6) 40993 * COMPLEX_EXPR: Expression trees. (line 6) 40994 * COMPLEX_TYPE: Types. (line 6) 40995 * COMPONENT_REF: Expression trees. (line 6) 40996 * Compound Expressions: Compound Expressions. 40997 (line 6) 40998 * Compound Lvalues: Compound Lvalues. (line 6) 40999 * COMPOUND_EXPR: Expression trees. (line 6) 41000 * COMPOUND_LITERAL_EXPR: Expression trees. (line 6) 41001 * COMPOUND_LITERAL_EXPR_DECL: Expression trees. (line 608) 41002 * COMPOUND_LITERAL_EXPR_DECL_STMT: Expression trees. (line 608) 41003 * computed jump: Edges. (line 128) 41004 * computing the length of an insn: Insn Lengths. (line 6) 41005 * concat: Regs and Memory. (line 385) 41006 * concatn: Regs and Memory. (line 391) 41007 * cond: Comparisons. (line 90) 41008 * cond and attributes: Expressions. (line 37) 41009 * cond_exec: Side Effects. (line 248) 41010 * COND_EXPR: Expression trees. (line 6) 41011 * condition code register: Regs and Memory. (line 307) 41012 * condition code status: Condition Code. (line 6) 41013 * condition codes: Comparisons. (line 20) 41014 * conditional execution: Conditional Execution. 41015 (line 6) 41016 * Conditional Expressions: Conditional Expressions. 41017 (line 6) 41018 * CONDITIONAL_REGISTER_USAGE: Register Basics. (line 60) 41019 * conditional_trap instruction pattern: Standard Names. (line 1379) 41020 * conditions, in patterns: Patterns. (line 43) 41021 * configuration file <1>: Filesystem. (line 6) 41022 * configuration file: Host Misc. (line 6) 41023 * configure terms: Configure Terms. (line 6) 41024 * CONJ_EXPR: Expression trees. (line 6) 41025 * const: Constants. (line 99) 41026 * const0_rtx: Constants. (line 16) 41027 * CONST0_RTX: Constants. (line 119) 41028 * CONST1_RTX: Constants. (line 119) 41029 * const1_rtx: Constants. (line 16) 41030 * const2_rtx: Constants. (line 16) 41031 * CONST2_RTX: Constants. (line 119) 41032 * CONST_DECL: Declarations. (line 6) 41033 * const_double: Constants. (line 32) 41034 * const_double, RTL sharing: Sharing. (line 29) 41035 * CONST_DOUBLE_LOW: Constants. (line 39) 41036 * CONST_DOUBLE_OK_FOR_CONSTRAINT_P: Old Constraints. (line 69) 41037 * CONST_DOUBLE_OK_FOR_LETTER_P: Old Constraints. (line 54) 41038 * const_double_operand: Machine-Independent Predicates. 41039 (line 21) 41040 * const_fixed: Constants. (line 52) 41041 * const_int: Constants. (line 8) 41042 * const_int and attribute tests: Expressions. (line 47) 41043 * const_int and attributes: Expressions. (line 10) 41044 * const_int, RTL sharing: Sharing. (line 23) 41045 * const_int_operand: Machine-Independent Predicates. 41046 (line 16) 41047 * CONST_OK_FOR_CONSTRAINT_P: Old Constraints. (line 49) 41048 * CONST_OK_FOR_LETTER_P: Old Constraints. (line 40) 41049 * const_string: Constants. (line 71) 41050 * const_string and attributes: Expressions. (line 20) 41051 * const_true_rtx: Constants. (line 26) 41052 * const_vector: Constants. (line 59) 41053 * const_vector, RTL sharing: Sharing. (line 32) 41054 * constant attributes: Constant Attributes. 41055 (line 6) 41056 * constant definitions: Constant Definitions. 41057 (line 6) 41058 * CONSTANT_ADDRESS_P: Addressing Modes. (line 29) 41059 * CONSTANT_ALIGNMENT: Storage Layout. (line 241) 41060 * CONSTANT_P: Addressing Modes. (line 35) 41061 * CONSTANT_POOL_ADDRESS_P: Flags. (line 10) 41062 * CONSTANT_POOL_BEFORE_FUNCTION: Data Output. (line 64) 41063 * constants in constraints: Simple Constraints. (line 60) 41064 * constm1_rtx: Constants. (line 16) 41065 * constraint modifier characters: Modifiers. (line 6) 41066 * constraint, matching: Simple Constraints. (line 132) 41067 * CONSTRAINT_LEN: Old Constraints. (line 12) 41068 * constraint_num: C Constraint Interface. 41069 (line 38) 41070 * constraint_satisfied_p: C Constraint Interface. 41071 (line 54) 41072 * constraints: Constraints. (line 6) 41073 * constraints, defining: Define Constraints. (line 6) 41074 * constraints, defining, obsolete method: Old Constraints. (line 6) 41075 * constraints, machine specific: Machine Constraints. 41076 (line 6) 41077 * constraints, testing: C Constraint Interface. 41078 (line 6) 41079 * constructor: Function Basics. (line 6) 41080 * CONSTRUCTOR: Expression trees. (line 6) 41081 * constructors, automatic calls: Collect2. (line 15) 41082 * constructors, output of: Initialization. (line 6) 41083 * container: Containers. (line 6) 41084 * CONTINUE_STMT: Function Bodies. (line 6) 41085 * contributors: Contributors. (line 6) 41086 * controlling register usage: Register Basics. (line 76) 41087 * controlling the compilation driver: Driver. (line 6) 41088 * conventions, run-time: Interface. (line 6) 41089 * conversions: Conversions. (line 6) 41090 * CONVERT_EXPR: Expression trees. (line 6) 41091 * copy constructor: Function Basics. (line 6) 41092 * copy_rtx: Addressing Modes. (line 182) 41093 * copy_rtx_if_shared: Sharing. (line 64) 41094 * copysignM3 instruction pattern: Standard Names. (line 602) 41095 * cosM2 instruction pattern: Standard Names. (line 481) 41096 * costs of instructions: Costs. (line 6) 41097 * CP_INTEGRAL_TYPE: Types. (line 72) 41098 * cp_namespace_decls: Namespaces. (line 44) 41099 * CP_TYPE_CONST_NON_VOLATILE_P: Types. (line 45) 41100 * CP_TYPE_CONST_P: Types. (line 36) 41101 * CP_TYPE_QUALS: Types. (line 6) 41102 * CP_TYPE_RESTRICT_P: Types. (line 42) 41103 * CP_TYPE_VOLATILE_P: Types. (line 39) 41104 * CPLUSPLUS_CPP_SPEC: Driver. (line 113) 41105 * CPP_SPEC: Driver. (line 106) 41106 * CQImode: Machine Modes. (line 202) 41107 * cross compilation and floating point: Floating Point. (line 6) 41108 * CRT_CALL_STATIC_FUNCTION: Sections. (line 112) 41109 * CRTSTUFF_T_CFLAGS: Target Fragment. (line 35) 41110 * CRTSTUFF_T_CFLAGS_S: Target Fragment. (line 39) 41111 * CSImode: Machine Modes. (line 202) 41112 * CTImode: Machine Modes. (line 202) 41113 * ctz: Arithmetic. (line 216) 41114 * CTZ_DEFINED_VALUE_AT_ZERO: Misc. (line 320) 41115 * ctzM2 instruction pattern: Standard Names. (line 630) 41116 * CUMULATIVE_ARGS: Register Arguments. (line 127) 41117 * current_function_epilogue_delay_list: Function Entry. (line 181) 41118 * current_function_is_leaf: Leaf Functions. (line 51) 41119 * current_function_outgoing_args_size: Stack Arguments. (line 45) 41120 * current_function_pops_args: Function Entry. (line 106) 41121 * current_function_pretend_args_size: Function Entry. (line 112) 41122 * current_function_uses_only_leaf_regs: Leaf Functions. (line 51) 41123 * current_insn_predicate: Conditional Execution. 41124 (line 26) 41125 * DAmode: Machine Modes. (line 152) 41126 * data bypass: Processor pipeline description. 41127 (line 197) 41128 * data dependence delays: Processor pipeline description. 41129 (line 6) 41130 * Data Dependency Analysis: Dependency analysis. 41131 (line 6) 41132 * data structures: Per-Function Data. (line 6) 41133 * DATA_ALIGNMENT: Storage Layout. (line 228) 41134 * DATA_SECTION_ASM_OP: Sections. (line 53) 41135 * DBR_OUTPUT_SEQEND: Instruction Output. (line 107) 41136 * dbr_sequence_length: Instruction Output. (line 106) 41137 * DBX_BLOCKS_FUNCTION_RELATIVE: DBX Options. (line 103) 41138 * DBX_CONTIN_CHAR: DBX Options. (line 66) 41139 * DBX_CONTIN_LENGTH: DBX Options. (line 56) 41140 * DBX_DEBUGGING_INFO: DBX Options. (line 9) 41141 * DBX_FUNCTION_FIRST: DBX Options. (line 97) 41142 * DBX_LINES_FUNCTION_RELATIVE: DBX Options. (line 109) 41143 * DBX_NO_XREFS: DBX Options. (line 50) 41144 * DBX_OUTPUT_LBRAC: DBX Hooks. (line 9) 41145 * DBX_OUTPUT_MAIN_SOURCE_FILE_END: File Names and DBX. (line 34) 41146 * DBX_OUTPUT_MAIN_SOURCE_FILENAME: File Names and DBX. (line 9) 41147 * DBX_OUTPUT_NFUN: DBX Hooks. (line 18) 41148 * DBX_OUTPUT_NULL_N_SO_AT_MAIN_SOURCE_FILE_END: File Names and DBX. 41149 (line 42) 41150 * DBX_OUTPUT_RBRAC: DBX Hooks. (line 15) 41151 * DBX_OUTPUT_SOURCE_LINE: DBX Hooks. (line 22) 41152 * DBX_REGISTER_NUMBER: All Debuggers. (line 9) 41153 * DBX_REGPARM_STABS_CODE: DBX Options. (line 87) 41154 * DBX_REGPARM_STABS_LETTER: DBX Options. (line 92) 41155 * DBX_STATIC_CONST_VAR_CODE: DBX Options. (line 82) 41156 * DBX_STATIC_STAB_DATA_SECTION: DBX Options. (line 73) 41157 * DBX_TYPE_DECL_STABS_CODE: DBX Options. (line 78) 41158 * DBX_USE_BINCL: DBX Options. (line 115) 41159 * DCmode: Machine Modes. (line 197) 41160 * DDmode: Machine Modes. (line 90) 41161 * De Morgan's law: Insn Canonicalizations. 41162 (line 57) 41163 * dead_or_set_p: define_peephole. (line 65) 41164 * DEBUG_SYMS_TEXT: DBX Options. (line 25) 41165 * DEBUGGER_ARG_OFFSET: All Debuggers. (line 37) 41166 * DEBUGGER_AUTO_OFFSET: All Debuggers. (line 28) 41167 * decimal float library: Decimal float library routines. 41168 (line 6) 41169 * DECL_ALIGN: Declarations. (line 6) 41170 * DECL_ANTICIPATED: Function Basics. (line 48) 41171 * DECL_ARGUMENTS: Function Basics. (line 163) 41172 * DECL_ARRAY_DELETE_OPERATOR_P: Function Basics. (line 184) 41173 * DECL_ARTIFICIAL <1>: Function Basics. (line 6) 41174 * DECL_ARTIFICIAL <2>: Working with declarations. 41175 (line 24) 41176 * DECL_ARTIFICIAL: Function Basics. (line 155) 41177 * DECL_ASSEMBLER_NAME: Function Basics. (line 6) 41178 * DECL_ATTRIBUTES: Attributes. (line 22) 41179 * DECL_BASE_CONSTRUCTOR_P: Function Basics. (line 94) 41180 * DECL_CLASS_SCOPE_P: Working with declarations. 41181 (line 41) 41182 * DECL_COMPLETE_CONSTRUCTOR_P: Function Basics. (line 90) 41183 * DECL_COMPLETE_DESTRUCTOR_P: Function Basics. (line 104) 41184 * DECL_CONST_MEMFUNC_P: Function Basics. (line 77) 41185 * DECL_CONSTRUCTOR_P: Function Basics. (line 83) 41186 * DECL_CONTEXT: Namespaces. (line 26) 41187 * DECL_CONV_FN_P: Function Basics. (line 6) 41188 * DECL_COPY_CONSTRUCTOR_P: Function Basics. (line 98) 41189 * DECL_DESTRUCTOR_P: Function Basics. (line 101) 41190 * DECL_EXTERN_C_FUNCTION_P: Function Basics. (line 52) 41191 * DECL_EXTERNAL <1>: Function Basics. (line 38) 41192 * DECL_EXTERNAL: Declarations. (line 6) 41193 * DECL_FUNCTION_MEMBER_P: Function Basics. (line 67) 41194 * DECL_FUNCTION_SCOPE_P: Working with declarations. 41195 (line 44) 41196 * DECL_FUNCTION_SPECIFIC_OPTIMIZATION: Function Basics. (line 194) 41197 * DECL_FUNCTION_SPECIFIC_TARGET: Function Basics. (line 188) 41198 * DECL_GLOBAL_CTOR_P: Function Basics. (line 114) 41199 * DECL_GLOBAL_DTOR_P: Function Basics. (line 118) 41200 * DECL_INITIAL: Declarations. (line 6) 41201 * DECL_LINKONCE_P: Function Basics. (line 6) 41202 * DECL_LOCAL_FUNCTION_P: Function Basics. (line 44) 41203 * DECL_MAIN_P: Function Basics. (line 7) 41204 * DECL_NAME <1>: Function Basics. (line 6) 41205 * DECL_NAME <2>: Namespaces. (line 15) 41206 * DECL_NAME: Working with declarations. 41207 (line 7) 41208 * DECL_NAMESPACE_ALIAS: Namespaces. (line 30) 41209 * DECL_NAMESPACE_SCOPE_P: Working with declarations. 41210 (line 37) 41211 * DECL_NAMESPACE_STD_P: Namespaces. (line 40) 41212 * DECL_NON_THUNK_FUNCTION_P: Function Basics. (line 144) 41213 * DECL_NONCONVERTING_P: Function Basics. (line 86) 41214 * DECL_NONSTATIC_MEMBER_FUNCTION_P: Function Basics. (line 74) 41215 * DECL_OVERLOADED_OPERATOR_P: Function Basics. (line 108) 41216 * DECL_RESULT: Function Basics. (line 168) 41217 * DECL_SIZE: Declarations. (line 6) 41218 * DECL_STATIC_FUNCTION_P: Function Basics. (line 71) 41219 * DECL_STMT: Function Bodies. (line 6) 41220 * DECL_STMT_DECL: Function Bodies. (line 6) 41221 * DECL_THUNK_P: Function Basics. (line 122) 41222 * DECL_VOLATILE_MEMFUNC_P: Function Basics. (line 80) 41223 * declaration: Declarations. (line 6) 41224 * declarations, RTL: RTL Declarations. (line 6) 41225 * DECLARE_LIBRARY_RENAMES: Library Calls. (line 9) 41226 * decrement_and_branch_until_zero instruction pattern: Standard Names. 41227 (line 1120) 41228 * def_optype_d: Manipulating GIMPLE statements. 41229 (line 94) 41230 * default: GTY Options. (line 82) 41231 * default_file_start: File Framework. (line 9) 41232 * DEFAULT_GDB_EXTENSIONS: DBX Options. (line 18) 41233 * DEFAULT_PCC_STRUCT_RETURN: Aggregate Return. (line 34) 41234 * DEFAULT_SIGNED_CHAR: Type Layout. (line 154) 41235 * define_address_constraint: Define Constraints. (line 107) 41236 * define_asm_attributes: Tagging Insns. (line 73) 41237 * define_attr: Defining Attributes. 41238 (line 6) 41239 * define_automaton: Processor pipeline description. 41240 (line 53) 41241 * define_bypass: Processor pipeline description. 41242 (line 197) 41243 * define_code_attr: Code Iterators. (line 6) 41244 * define_code_iterator: Code Iterators. (line 6) 41245 * define_cond_exec: Conditional Execution. 41246 (line 13) 41247 * define_constants: Constant Definitions. 41248 (line 6) 41249 * define_constraint: Define Constraints. (line 48) 41250 * define_cpu_unit: Processor pipeline description. 41251 (line 68) 41252 * define_delay: Delay Slots. (line 25) 41253 * define_expand: Expander Definitions. 41254 (line 11) 41255 * define_insn: Patterns. (line 6) 41256 * define_insn example: Example. (line 6) 41257 * define_insn_and_split: Insn Splitting. (line 170) 41258 * define_insn_reservation: Processor pipeline description. 41259 (line 106) 41260 * define_memory_constraint: Define Constraints. (line 88) 41261 * define_mode_attr: Substitutions. (line 6) 41262 * define_mode_iterator: Defining Mode Iterators. 41263 (line 6) 41264 * define_peephole: define_peephole. (line 6) 41265 * define_peephole2: define_peephole2. (line 6) 41266 * define_predicate: Defining Predicates. 41267 (line 6) 41268 * define_query_cpu_unit: Processor pipeline description. 41269 (line 90) 41270 * define_register_constraint: Define Constraints. (line 28) 41271 * define_reservation: Processor pipeline description. 41272 (line 186) 41273 * define_special_predicate: Defining Predicates. 41274 (line 6) 41275 * define_split: Insn Splitting. (line 32) 41276 * defining attributes and their values: Defining Attributes. 41277 (line 6) 41278 * defining constraints: Define Constraints. (line 6) 41279 * defining constraints, obsolete method: Old Constraints. (line 6) 41280 * defining jump instruction patterns: Jump Patterns. (line 6) 41281 * defining looping instruction patterns: Looping Patterns. (line 6) 41282 * defining peephole optimizers: Peephole Definitions. 41283 (line 6) 41284 * defining predicates: Defining Predicates. 41285 (line 6) 41286 * defining RTL sequences for code generation: Expander Definitions. 41287 (line 6) 41288 * delay slots, defining: Delay Slots. (line 6) 41289 * DELAY_SLOTS_FOR_EPILOGUE: Function Entry. (line 163) 41290 * deletable: GTY Options. (line 150) 41291 * DELETE_IF_ORDINARY: Filesystem. (line 79) 41292 * Dependent Patterns: Dependent Patterns. (line 6) 41293 * desc: GTY Options. (line 82) 41294 * destructor: Function Basics. (line 6) 41295 * destructors, output of: Initialization. (line 6) 41296 * deterministic finite state automaton: Processor pipeline description. 41297 (line 296) 41298 * DF_SIZE: Type Layout. (line 130) 41299 * DFmode: Machine Modes. (line 73) 41300 * digits in constraint: Simple Constraints. (line 120) 41301 * DImode: Machine Modes. (line 45) 41302 * DIR_SEPARATOR: Filesystem. (line 18) 41303 * DIR_SEPARATOR_2: Filesystem. (line 19) 41304 * directory options .md: Including Patterns. (line 44) 41305 * disabling certain registers: Register Basics. (line 76) 41306 * dispatch table: Dispatch Tables. (line 8) 41307 * div: Arithmetic. (line 111) 41308 * div and attributes: Expressions. (line 64) 41309 * division: Arithmetic. (line 131) 41310 * divM3 instruction pattern: Standard Names. (line 222) 41311 * divmodM4 instruction pattern: Standard Names. (line 411) 41312 * DO_BODY: Function Bodies. (line 6) 41313 * DO_COND: Function Bodies. (line 6) 41314 * DO_STMT: Function Bodies. (line 6) 41315 * DOLLARS_IN_IDENTIFIERS: Misc. (line 496) 41316 * doloop_begin instruction pattern: Standard Names. (line 1151) 41317 * doloop_end instruction pattern: Standard Names. (line 1130) 41318 * DONE: Expander Definitions. 41319 (line 74) 41320 * DONT_USE_BUILTIN_SETJMP: Exception Region Output. 41321 (line 70) 41322 * DOUBLE_TYPE_SIZE: Type Layout. (line 53) 41323 * DQmode: Machine Modes. (line 115) 41324 * driver: Driver. (line 6) 41325 * DRIVER_SELF_SPECS: Driver. (line 71) 41326 * DUMPFILE_FORMAT: Filesystem. (line 67) 41327 * DWARF2_ASM_LINE_DEBUG_INFO: SDB and DWARF. (line 36) 41328 * DWARF2_DEBUGGING_INFO: SDB and DWARF. (line 13) 41329 * DWARF2_FRAME_INFO: SDB and DWARF. (line 30) 41330 * DWARF2_FRAME_REG_OUT: Frame Registers. (line 133) 41331 * DWARF2_UNWIND_INFO: Exception Region Output. 41332 (line 40) 41333 * DWARF_ALT_FRAME_RETURN_COLUMN: Frame Layout. (line 152) 41334 * DWARF_CIE_DATA_ALIGNMENT: Exception Region Output. 41335 (line 75) 41336 * DWARF_FRAME_REGISTERS: Frame Registers. (line 93) 41337 * DWARF_FRAME_REGNUM: Frame Registers. (line 125) 41338 * DWARF_REG_TO_UNWIND_COLUMN: Frame Registers. (line 117) 41339 * DWARF_ZERO_REG: Frame Layout. (line 163) 41340 * DYNAMIC_CHAIN_ADDRESS: Frame Layout. (line 92) 41341 * E in constraint: Simple Constraints. (line 79) 41342 * earlyclobber operand: Modifiers. (line 25) 41343 * edge: Edges. (line 6) 41344 * edge in the flow graph: Edges. (line 6) 41345 * edge iterators: Edges. (line 15) 41346 * edge splitting: Maintaining the CFG. 41347 (line 118) 41348 * EDGE_ABNORMAL: Edges. (line 128) 41349 * EDGE_ABNORMAL, EDGE_ABNORMAL_CALL: Edges. (line 171) 41350 * EDGE_ABNORMAL, EDGE_EH: Edges. (line 96) 41351 * EDGE_ABNORMAL, EDGE_SIBCALL: Edges. (line 122) 41352 * EDGE_FALLTHRU, force_nonfallthru: Edges. (line 86) 41353 * EDOM, implicit usage: Library Calls. (line 58) 41354 * EH_FRAME_IN_DATA_SECTION: Exception Region Output. 41355 (line 20) 41356 * EH_FRAME_SECTION_NAME: Exception Region Output. 41357 (line 10) 41358 * eh_return instruction pattern: Standard Names. (line 1319) 41359 * EH_RETURN_DATA_REGNO: Exception Handling. (line 7) 41360 * EH_RETURN_HANDLER_RTX: Exception Handling. (line 39) 41361 * EH_RETURN_STACKADJ_RTX: Exception Handling. (line 22) 41362 * EH_TABLES_CAN_BE_READ_ONLY: Exception Region Output. 41363 (line 29) 41364 * EH_USES: Function Entry. (line 158) 41365 * ei_edge: Edges. (line 43) 41366 * ei_end_p: Edges. (line 27) 41367 * ei_last: Edges. (line 23) 41368 * ei_next: Edges. (line 35) 41369 * ei_one_before_end_p: Edges. (line 31) 41370 * ei_prev: Edges. (line 39) 41371 * ei_safe_safe: Edges. (line 47) 41372 * ei_start: Edges. (line 19) 41373 * ELIGIBLE_FOR_EPILOGUE_DELAY: Function Entry. (line 169) 41374 * ELIMINABLE_REGS: Elimination. (line 44) 41375 * ELSE_CLAUSE: Function Bodies. (line 6) 41376 * Embedded C: Fixed-point fractional library routines. 41377 (line 6) 41378 * EMIT_MODE_SET: Mode Switching. (line 74) 41379 * Empty Statements: Empty Statements. (line 6) 41380 * EMPTY_CLASS_EXPR: Function Bodies. (line 6) 41381 * EMPTY_FIELD_BOUNDARY: Storage Layout. (line 295) 41382 * Emulated TLS: Emulated TLS. (line 6) 41383 * ENABLE_EXECUTE_STACK: Trampolines. (line 110) 41384 * enabled: Disable Insn Alternatives. 41385 (line 6) 41386 * ENDFILE_SPEC: Driver. (line 218) 41387 * endianness: Portability. (line 21) 41388 * ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR: Basic Blocks. (line 28) 41389 * enum machine_mode: Machine Modes. (line 6) 41390 * enum reg_class: Register Classes. (line 65) 41391 * ENUMERAL_TYPE: Types. (line 6) 41392 * epilogue: Function Entry. (line 6) 41393 * epilogue instruction pattern: Standard Names. (line 1351) 41394 * EPILOGUE_USES: Function Entry. (line 152) 41395 * eq: Comparisons. (line 52) 41396 * eq and attributes: Expressions. (line 64) 41397 * eq_attr: Expressions. (line 85) 41398 * EQ_EXPR: Expression trees. (line 6) 41399 * equal: Comparisons. (line 52) 41400 * errno, implicit usage: Library Calls. (line 70) 41401 * EXACT_DIV_EXPR: Expression trees. (line 6) 41402 * examining SSA_NAMEs: SSA. (line 218) 41403 * exception handling <1>: Edges. (line 96) 41404 * exception handling: Exception Handling. (line 6) 41405 * exception_receiver instruction pattern: Standard Names. (line 1283) 41406 * exclamation point: Multi-Alternative. (line 47) 41407 * exclusion_set: Processor pipeline description. 41408 (line 215) 41409 * exclusive-or, bitwise: Arithmetic. (line 163) 41410 * EXIT_EXPR: Expression trees. (line 6) 41411 * EXIT_IGNORE_STACK: Function Entry. (line 140) 41412 * expander definitions: Expander Definitions. 41413 (line 6) 41414 * expM2 instruction pattern: Standard Names. (line 497) 41415 * expr_list: Insns. (line 505) 41416 * EXPR_STMT: Function Bodies. (line 6) 41417 * EXPR_STMT_EXPR: Function Bodies. (line 6) 41418 * expression: Expression trees. (line 6) 41419 * expression codes: RTL Objects. (line 47) 41420 * extendMN2 instruction pattern: Standard Names. (line 826) 41421 * extensible constraints: Simple Constraints. (line 163) 41422 * EXTRA_ADDRESS_CONSTRAINT: Old Constraints. (line 123) 41423 * EXTRA_CONSTRAINT: Old Constraints. (line 74) 41424 * EXTRA_CONSTRAINT_STR: Old Constraints. (line 95) 41425 * EXTRA_MEMORY_CONSTRAINT: Old Constraints. (line 100) 41426 * EXTRA_SPECS: Driver. (line 245) 41427 * extv instruction pattern: Standard Names. (line 862) 41428 * extzv instruction pattern: Standard Names. (line 877) 41429 * F in constraint: Simple Constraints. (line 84) 41430 * FAIL: Expander Definitions. 41431 (line 80) 41432 * fall-thru: Edges. (line 69) 41433 * FATAL_EXIT_CODE: Host Misc. (line 6) 41434 * FDL, GNU Free Documentation License: GNU Free Documentation License. 41435 (line 6) 41436 * features, optional, in system conventions: Run-time Target. 41437 (line 59) 41438 * ffs: Arithmetic. (line 202) 41439 * ffsM2 instruction pattern: Standard Names. (line 611) 41440 * FIELD_DECL: Declarations. (line 6) 41441 * file_end_indicate_exec_stack: File Framework. (line 41) 41442 * files and passes of the compiler: Passes. (line 6) 41443 * files, generated: Files. (line 6) 41444 * final_absence_set: Processor pipeline description. 41445 (line 215) 41446 * FINAL_PRESCAN_INSN: Instruction Output. (line 46) 41447 * final_presence_set: Processor pipeline description. 41448 (line 215) 41449 * final_scan_insn: Function Entry. (line 181) 41450 * final_sequence: Instruction Output. (line 117) 41451 * FIND_BASE_TERM: Addressing Modes. (line 110) 41452 * FINI_ARRAY_SECTION_ASM_OP: Sections. (line 105) 41453 * FINI_SECTION_ASM_OP: Sections. (line 90) 41454 * finite state automaton minimization: Processor pipeline description. 41455 (line 296) 41456 * FIRST_PARM_OFFSET: Frame Layout. (line 67) 41457 * FIRST_PARM_OFFSET and virtual registers: Regs and Memory. (line 65) 41458 * FIRST_PSEUDO_REGISTER: Register Basics. (line 9) 41459 * FIRST_STACK_REG: Stack Registers. (line 23) 41460 * FIRST_VIRTUAL_REGISTER: Regs and Memory. (line 51) 41461 * fix: Conversions. (line 66) 41462 * FIX_TRUNC_EXPR: Expression trees. (line 6) 41463 * fix_truncMN2 instruction pattern: Standard Names. (line 813) 41464 * fixed register: Register Basics. (line 15) 41465 * fixed-point fractional library: Fixed-point fractional library routines. 41466 (line 6) 41467 * FIXED_CONVERT_EXPR: Expression trees. (line 6) 41468 * FIXED_CST: Expression trees. (line 6) 41469 * FIXED_POINT_TYPE: Types. (line 6) 41470 * FIXED_REGISTERS: Register Basics. (line 15) 41471 * fixed_regs: Register Basics. (line 59) 41472 * fixMN2 instruction pattern: Standard Names. (line 793) 41473 * FIXUNS_TRUNC_LIKE_FIX_TRUNC: Misc. (line 100) 41474 * fixuns_truncMN2 instruction pattern: Standard Names. (line 817) 41475 * fixunsMN2 instruction pattern: Standard Names. (line 802) 41476 * flags in RTL expression: Flags. (line 6) 41477 * float: Conversions. (line 58) 41478 * FLOAT_EXPR: Expression trees. (line 6) 41479 * float_extend: Conversions. (line 33) 41480 * FLOAT_LIB_COMPARE_RETURNS_BOOL: Library Calls. (line 25) 41481 * FLOAT_STORE_FLAG_VALUE: Misc. (line 301) 41482 * float_truncate: Conversions. (line 53) 41483 * FLOAT_TYPE_SIZE: Type Layout. (line 49) 41484 * FLOAT_WORDS_BIG_ENDIAN: Storage Layout. (line 43) 41485 * FLOAT_WORDS_BIG_ENDIAN, (lack of) effect on subreg: Regs and Memory. 41486 (line 226) 41487 * floating point and cross compilation: Floating Point. (line 6) 41488 * Floating Point Emulation: Target Fragment. (line 15) 41489 * floating point emulation library, US Software GOFAST: Library Calls. 41490 (line 44) 41491 * floatMN2 instruction pattern: Standard Names. (line 785) 41492 * floatunsMN2 instruction pattern: Standard Names. (line 789) 41493 * FLOOR_DIV_EXPR: Expression trees. (line 6) 41494 * FLOOR_MOD_EXPR: Expression trees. (line 6) 41495 * floorM2 instruction pattern: Standard Names. (line 532) 41496 * flow-insensitive alias analysis: Alias analysis. (line 6) 41497 * flow-sensitive alias analysis: Alias analysis. (line 6) 41498 * fmodM3 instruction pattern: Standard Names. (line 463) 41499 * FOR_BODY: Function Bodies. (line 6) 41500 * FOR_COND: Function Bodies. (line 6) 41501 * FOR_EXPR: Function Bodies. (line 6) 41502 * FOR_INIT_STMT: Function Bodies. (line 6) 41503 * FOR_STMT: Function Bodies. (line 6) 41504 * FORCE_CODE_SECTION_ALIGN: Sections. (line 136) 41505 * force_reg: Standard Names. (line 36) 41506 * fract_convert: Conversions. (line 82) 41507 * FRACT_TYPE_SIZE: Type Layout. (line 68) 41508 * fractional types: Fixed-point fractional library routines. 41509 (line 6) 41510 * fractMN2 instruction pattern: Standard Names. (line 835) 41511 * fractunsMN2 instruction pattern: Standard Names. (line 850) 41512 * frame layout: Frame Layout. (line 6) 41513 * FRAME_ADDR_RTX: Frame Layout. (line 116) 41514 * FRAME_GROWS_DOWNWARD: Frame Layout. (line 31) 41515 * FRAME_GROWS_DOWNWARD and virtual registers: Regs and Memory. 41516 (line 69) 41517 * FRAME_POINTER_CFA_OFFSET: Frame Layout. (line 212) 41518 * frame_pointer_needed: Function Entry. (line 34) 41519 * FRAME_POINTER_REGNUM: Frame Registers. (line 14) 41520 * FRAME_POINTER_REGNUM and virtual registers: Regs and Memory. 41521 (line 74) 41522 * FRAME_POINTER_REQUIRED: Elimination. (line 9) 41523 * frame_pointer_rtx: Frame Registers. (line 85) 41524 * frame_related: Flags. (line 242) 41525 * frame_related, in insn, call_insn, jump_insn, barrier, and set: Flags. 41526 (line 125) 41527 * frame_related, in mem: Flags. (line 103) 41528 * frame_related, in reg: Flags. (line 112) 41529 * frame_related, in symbol_ref: Flags. (line 183) 41530 * frequency, count, BB_FREQ_BASE: Profile information. 41531 (line 30) 41532 * ftruncM2 instruction pattern: Standard Names. (line 808) 41533 * function: Functions. (line 6) 41534 * function body: Function Bodies. (line 6) 41535 * function call conventions: Interface. (line 6) 41536 * function entry and exit: Function Entry. (line 6) 41537 * function entry point, alternate function entry point: Edges. 41538 (line 180) 41539 * function-call insns: Calls. (line 6) 41540 * FUNCTION_ARG: Register Arguments. (line 11) 41541 * FUNCTION_ARG_ADVANCE: Register Arguments. (line 186) 41542 * FUNCTION_ARG_BOUNDARY: Register Arguments. (line 239) 41543 * FUNCTION_ARG_OFFSET: Register Arguments. (line 197) 41544 * FUNCTION_ARG_PADDING: Register Arguments. (line 204) 41545 * FUNCTION_ARG_REGNO_P: Register Arguments. (line 244) 41546 * FUNCTION_BOUNDARY: Storage Layout. (line 170) 41547 * FUNCTION_DECL: Functions. (line 6) 41548 * FUNCTION_INCOMING_ARG: Register Arguments. (line 68) 41549 * FUNCTION_MODE: Misc. (line 356) 41550 * FUNCTION_OUTGOING_VALUE: Scalar Return. (line 56) 41551 * FUNCTION_PROFILER: Profiling. (line 9) 41552 * FUNCTION_TYPE: Types. (line 6) 41553 * FUNCTION_VALUE: Scalar Return. (line 52) 41554 * FUNCTION_VALUE_REGNO_P: Scalar Return. (line 69) 41555 * functions, leaf: Leaf Functions. (line 6) 41556 * fundamental type: Types. (line 6) 41557 * G in constraint: Simple Constraints. (line 88) 41558 * g in constraint: Simple Constraints. (line 110) 41559 * garbage collector, invocation: Invoking the garbage collector. 41560 (line 6) 41561 * GCC and portability: Portability. (line 6) 41562 * GCC_DRIVER_HOST_INITIALIZATION: Host Misc. (line 36) 41563 * gcov_type: Profile information. 41564 (line 41) 41565 * ge: Comparisons. (line 72) 41566 * ge and attributes: Expressions. (line 64) 41567 * GE_EXPR: Expression trees. (line 6) 41568 * GEN_ERRNO_RTX: Library Calls. (line 71) 41569 * gencodes: RTL passes. (line 18) 41570 * general_operand: Machine-Independent Predicates. 41571 (line 105) 41572 * GENERAL_REGS: Register Classes. (line 23) 41573 * generated files: Files. (line 6) 41574 * generating assembler output: Output Statement. (line 6) 41575 * generating insns: RTL Template. (line 6) 41576 * GENERIC <1>: Parsing pass. (line 6) 41577 * GENERIC <2>: GENERIC. (line 6) 41578 * GENERIC: Gimplification pass. 41579 (line 12) 41580 * generic predicates: Machine-Independent Predicates. 41581 (line 6) 41582 * genflags: RTL passes. (line 18) 41583 * get_attr: Expressions. (line 80) 41584 * get_attr_length: Insn Lengths. (line 46) 41585 * GET_CLASS_NARROWEST_MODE: Machine Modes. (line 333) 41586 * GET_CODE: RTL Objects. (line 47) 41587 * get_frame_size: Elimination. (line 31) 41588 * get_insns: Insns. (line 34) 41589 * get_last_insn: Insns. (line 34) 41590 * GET_MODE: Machine Modes. (line 280) 41591 * GET_MODE_ALIGNMENT: Machine Modes. (line 320) 41592 * GET_MODE_BITSIZE: Machine Modes. (line 304) 41593 * GET_MODE_CLASS: Machine Modes. (line 294) 41594 * GET_MODE_FBIT: Machine Modes. (line 311) 41595 * GET_MODE_IBIT: Machine Modes. (line 307) 41596 * GET_MODE_MASK: Machine Modes. (line 315) 41597 * GET_MODE_NAME: Machine Modes. (line 291) 41598 * GET_MODE_NUNITS: Machine Modes. (line 329) 41599 * GET_MODE_SIZE: Machine Modes. (line 301) 41600 * GET_MODE_UNIT_SIZE: Machine Modes. (line 323) 41601 * GET_MODE_WIDER_MODE: Machine Modes. (line 297) 41602 * GET_RTX_CLASS: RTL Classes. (line 6) 41603 * GET_RTX_FORMAT: RTL Classes. (line 130) 41604 * GET_RTX_LENGTH: RTL Classes. (line 127) 41605 * geu: Comparisons. (line 72) 41606 * geu and attributes: Expressions. (line 64) 41607 * GGC: Type Information. (line 6) 41608 * ggc_collect: Invoking the garbage collector. 41609 (line 6) 41610 * GIMPLE <1>: Gimplification pass. 41611 (line 6) 41612 * GIMPLE <2>: Parsing pass. (line 14) 41613 * GIMPLE: GIMPLE. (line 6) 41614 * GIMPLE Exception Handling: GIMPLE Exception Handling. 41615 (line 6) 41616 * GIMPLE instruction set: GIMPLE instruction set. 41617 (line 6) 41618 * GIMPLE sequences: GIMPLE sequences. (line 6) 41619 * gimple_addresses_taken: Manipulating GIMPLE statements. 41620 (line 90) 41621 * GIMPLE_ASM: GIMPLE_ASM. (line 6) 41622 * gimple_asm_clear_volatile: GIMPLE_ASM. (line 63) 41623 * gimple_asm_clobber_op: GIMPLE_ASM. (line 46) 41624 * gimple_asm_input_op: GIMPLE_ASM. (line 30) 41625 * gimple_asm_output_op: GIMPLE_ASM. (line 38) 41626 * gimple_asm_set_clobber_op: GIMPLE_ASM. (line 50) 41627 * gimple_asm_set_input_op: GIMPLE_ASM. (line 34) 41628 * gimple_asm_set_output_op: GIMPLE_ASM. (line 42) 41629 * gimple_asm_set_volatile: GIMPLE_ASM. (line 60) 41630 * gimple_asm_volatile_p: GIMPLE_ASM. (line 57) 41631 * GIMPLE_ASSIGN: GIMPLE_ASSIGN. (line 6) 41632 * gimple_assign_cast_p: GIMPLE_ASSIGN. (line 89) 41633 * gimple_assign_lhs: GIMPLE_ASSIGN. (line 51) 41634 * gimple_assign_rhs1: GIMPLE_ASSIGN. (line 57) 41635 * gimple_assign_rhs2: GIMPLE_ASSIGN. (line 64) 41636 * gimple_assign_set_lhs: GIMPLE_ASSIGN. (line 71) 41637 * gimple_assign_set_rhs1: GIMPLE_ASSIGN. (line 74) 41638 * gimple_assign_set_rhs2: GIMPLE_ASSIGN. (line 85) 41639 * gimple_bb: Manipulating GIMPLE statements. 41640 (line 18) 41641 * GIMPLE_BIND: GIMPLE_BIND. (line 6) 41642 * gimple_bind_add_seq: GIMPLE_BIND. (line 36) 41643 * gimple_bind_add_stmt: GIMPLE_BIND. (line 32) 41644 * gimple_bind_append_vars: GIMPLE_BIND. (line 19) 41645 * gimple_bind_block: GIMPLE_BIND. (line 40) 41646 * gimple_bind_body: GIMPLE_BIND. (line 23) 41647 * gimple_bind_set_block: GIMPLE_BIND. (line 45) 41648 * gimple_bind_set_body: GIMPLE_BIND. (line 28) 41649 * gimple_bind_set_vars: GIMPLE_BIND. (line 15) 41650 * gimple_bind_vars: GIMPLE_BIND. (line 12) 41651 * gimple_block: Manipulating GIMPLE statements. 41652 (line 21) 41653 * gimple_build_asm: GIMPLE_ASM. (line 8) 41654 * gimple_build_asm_vec: GIMPLE_ASM. (line 17) 41655 * gimple_build_assign: GIMPLE_ASSIGN. (line 7) 41656 * gimple_build_assign_with_ops: GIMPLE_ASSIGN. (line 30) 41657 * gimple_build_bind: GIMPLE_BIND. (line 8) 41658 * gimple_build_call: GIMPLE_CALL. (line 8) 41659 * gimple_build_call_from_tree: GIMPLE_CALL. (line 16) 41660 * gimple_build_call_vec: GIMPLE_CALL. (line 25) 41661 * gimple_build_catch: GIMPLE_CATCH. (line 8) 41662 * gimple_build_cdt: GIMPLE_CHANGE_DYNAMIC_TYPE. 41663 (line 7) 41664 * gimple_build_cond: GIMPLE_COND. (line 8) 41665 * gimple_build_cond_from_tree: GIMPLE_COND. (line 16) 41666 * gimple_build_eh_filter: GIMPLE_EH_FILTER. (line 8) 41667 * gimple_build_goto: GIMPLE_LABEL. (line 18) 41668 * gimple_build_label: GIMPLE_LABEL. (line 7) 41669 * gimple_build_nop: GIMPLE_NOP. (line 7) 41670 * gimple_build_omp_atomic_load: GIMPLE_OMP_ATOMIC_LOAD. 41671 (line 8) 41672 * gimple_build_omp_atomic_store: GIMPLE_OMP_ATOMIC_STORE. 41673 (line 7) 41674 * gimple_build_omp_continue: GIMPLE_OMP_CONTINUE. 41675 (line 8) 41676 * gimple_build_omp_critical: GIMPLE_OMP_CRITICAL. 41677 (line 8) 41678 * gimple_build_omp_for: GIMPLE_OMP_FOR. (line 9) 41679 * gimple_build_omp_master: GIMPLE_OMP_MASTER. (line 7) 41680 * gimple_build_omp_ordered: GIMPLE_OMP_ORDERED. (line 7) 41681 * gimple_build_omp_parallel: GIMPLE_OMP_PARALLEL. 41682 (line 8) 41683 * gimple_build_omp_return: GIMPLE_OMP_RETURN. (line 7) 41684 * gimple_build_omp_section: GIMPLE_OMP_SECTION. (line 7) 41685 * gimple_build_omp_sections: GIMPLE_OMP_SECTIONS. 41686 (line 8) 41687 * gimple_build_omp_sections_switch: GIMPLE_OMP_SECTIONS. 41688 (line 14) 41689 * gimple_build_omp_single: GIMPLE_OMP_SINGLE. (line 8) 41690 * gimple_build_resx: GIMPLE_RESX. (line 7) 41691 * gimple_build_return: GIMPLE_RETURN. (line 7) 41692 * gimple_build_switch: GIMPLE_SWITCH. (line 8) 41693 * gimple_build_switch_vec: GIMPLE_SWITCH. (line 16) 41694 * gimple_build_try: GIMPLE_TRY. (line 8) 41695 * gimple_build_wce: GIMPLE_WITH_CLEANUP_EXPR. 41696 (line 7) 41697 * GIMPLE_CALL: GIMPLE_CALL. (line 6) 41698 * gimple_call_arg: GIMPLE_CALL. (line 66) 41699 * gimple_call_cannot_inline_p: GIMPLE_CALL. (line 91) 41700 * gimple_call_chain: GIMPLE_CALL. (line 57) 41701 * gimple_call_copy_skip_args: GIMPLE_CALL. (line 98) 41702 * gimple_call_fn: GIMPLE_CALL. (line 38) 41703 * gimple_call_fndecl: GIMPLE_CALL. (line 46) 41704 * gimple_call_lhs: GIMPLE_CALL. (line 29) 41705 * gimple_call_mark_uninlinable: GIMPLE_CALL. (line 88) 41706 * gimple_call_noreturn_p: GIMPLE_CALL. (line 94) 41707 * gimple_call_return_type: GIMPLE_CALL. (line 54) 41708 * gimple_call_set_arg: GIMPLE_CALL. (line 76) 41709 * gimple_call_set_chain: GIMPLE_CALL. (line 60) 41710 * gimple_call_set_fn: GIMPLE_CALL. (line 42) 41711 * gimple_call_set_fndecl: GIMPLE_CALL. (line 51) 41712 * gimple_call_set_lhs: GIMPLE_CALL. (line 35) 41713 * gimple_call_set_tail: GIMPLE_CALL. (line 80) 41714 * gimple_call_tail_p: GIMPLE_CALL. (line 85) 41715 * GIMPLE_CATCH: GIMPLE_CATCH. (line 6) 41716 * gimple_catch_handler: GIMPLE_CATCH. (line 20) 41717 * gimple_catch_set_handler: GIMPLE_CATCH. (line 28) 41718 * gimple_catch_set_types: GIMPLE_CATCH. (line 24) 41719 * gimple_catch_types: GIMPLE_CATCH. (line 13) 41720 * gimple_cdt_location: GIMPLE_CHANGE_DYNAMIC_TYPE. 41721 (line 24) 41722 * gimple_cdt_new_type: GIMPLE_CHANGE_DYNAMIC_TYPE. 41723 (line 11) 41724 * gimple_cdt_set_location: GIMPLE_CHANGE_DYNAMIC_TYPE. 41725 (line 32) 41726 * gimple_cdt_set_new_type: GIMPLE_CHANGE_DYNAMIC_TYPE. 41727 (line 20) 41728 * GIMPLE_CHANGE_DYNAMIC_TYPE: GIMPLE_CHANGE_DYNAMIC_TYPE. 41729 (line 6) 41730 * gimple_code: Manipulating GIMPLE statements. 41731 (line 15) 41732 * GIMPLE_COND: GIMPLE_COND. (line 6) 41733 * gimple_cond_false_label: GIMPLE_COND. (line 60) 41734 * gimple_cond_lhs: GIMPLE_COND. (line 30) 41735 * gimple_cond_make_false: GIMPLE_COND. (line 64) 41736 * gimple_cond_make_true: GIMPLE_COND. (line 67) 41737 * gimple_cond_rhs: GIMPLE_COND. (line 38) 41738 * gimple_cond_set_code: GIMPLE_COND. (line 26) 41739 * gimple_cond_set_false_label: GIMPLE_COND. (line 56) 41740 * gimple_cond_set_lhs: GIMPLE_COND. (line 34) 41741 * gimple_cond_set_rhs: GIMPLE_COND. (line 42) 41742 * gimple_cond_set_true_label: GIMPLE_COND. (line 51) 41743 * gimple_cond_true_label: GIMPLE_COND. (line 46) 41744 * gimple_copy: Manipulating GIMPLE statements. 41745 (line 147) 41746 * GIMPLE_EH_FILTER: GIMPLE_EH_FILTER. (line 6) 41747 * gimple_eh_filter_failure: GIMPLE_EH_FILTER. (line 19) 41748 * gimple_eh_filter_must_not_throw: GIMPLE_EH_FILTER. (line 33) 41749 * gimple_eh_filter_set_failure: GIMPLE_EH_FILTER. (line 29) 41750 * gimple_eh_filter_set_must_not_throw: GIMPLE_EH_FILTER. (line 37) 41751 * gimple_eh_filter_set_types: GIMPLE_EH_FILTER. (line 24) 41752 * gimple_eh_filter_types: GIMPLE_EH_FILTER. (line 12) 41753 * gimple_expr_type: Manipulating GIMPLE statements. 41754 (line 24) 41755 * gimple_goto_dest: GIMPLE_LABEL. (line 21) 41756 * gimple_goto_set_dest: GIMPLE_LABEL. (line 24) 41757 * gimple_has_mem_ops: Manipulating GIMPLE statements. 41758 (line 72) 41759 * gimple_has_ops: Manipulating GIMPLE statements. 41760 (line 69) 41761 * gimple_has_volatile_ops: Manipulating GIMPLE statements. 41762 (line 134) 41763 * GIMPLE_LABEL: GIMPLE_LABEL. (line 6) 41764 * gimple_label_label: GIMPLE_LABEL. (line 11) 41765 * gimple_label_set_label: GIMPLE_LABEL. (line 14) 41766 * gimple_loaded_syms: Manipulating GIMPLE statements. 41767 (line 122) 41768 * gimple_locus: Manipulating GIMPLE statements. 41769 (line 42) 41770 * gimple_locus_empty_p: Manipulating GIMPLE statements. 41771 (line 48) 41772 * gimple_modified_p: Manipulating GIMPLE statements. 41773 (line 130) 41774 * gimple_no_warning_p: Manipulating GIMPLE statements. 41775 (line 51) 41776 * GIMPLE_NOP: GIMPLE_NOP. (line 6) 41777 * gimple_nop_p: GIMPLE_NOP. (line 10) 41778 * gimple_num_ops <1>: Logical Operators. (line 76) 41779 * gimple_num_ops: Manipulating GIMPLE statements. 41780 (line 75) 41781 * GIMPLE_OMP_ATOMIC_LOAD: GIMPLE_OMP_ATOMIC_LOAD. 41782 (line 6) 41783 * gimple_omp_atomic_load_lhs: GIMPLE_OMP_ATOMIC_LOAD. 41784 (line 17) 41785 * gimple_omp_atomic_load_rhs: GIMPLE_OMP_ATOMIC_LOAD. 41786 (line 24) 41787 * gimple_omp_atomic_load_set_lhs: GIMPLE_OMP_ATOMIC_LOAD. 41788 (line 14) 41789 * gimple_omp_atomic_load_set_rhs: GIMPLE_OMP_ATOMIC_LOAD. 41790 (line 21) 41791 * GIMPLE_OMP_ATOMIC_STORE: GIMPLE_OMP_ATOMIC_STORE. 41792 (line 6) 41793 * gimple_omp_atomic_store_set_val: GIMPLE_OMP_ATOMIC_STORE. 41794 (line 12) 41795 * gimple_omp_atomic_store_val: GIMPLE_OMP_ATOMIC_STORE. 41796 (line 15) 41797 * gimple_omp_body: GIMPLE_OMP_PARALLEL. 41798 (line 24) 41799 * GIMPLE_OMP_CONTINUE: GIMPLE_OMP_CONTINUE. 41800 (line 6) 41801 * gimple_omp_continue_control_def: GIMPLE_OMP_CONTINUE. 41802 (line 13) 41803 * gimple_omp_continue_control_def_ptr: GIMPLE_OMP_CONTINUE. 41804 (line 17) 41805 * gimple_omp_continue_control_use: GIMPLE_OMP_CONTINUE. 41806 (line 24) 41807 * gimple_omp_continue_control_use_ptr: GIMPLE_OMP_CONTINUE. 41808 (line 28) 41809 * gimple_omp_continue_set_control_def: GIMPLE_OMP_CONTINUE. 41810 (line 20) 41811 * gimple_omp_continue_set_control_use: GIMPLE_OMP_CONTINUE. 41812 (line 31) 41813 * GIMPLE_OMP_CRITICAL: GIMPLE_OMP_CRITICAL. 41814 (line 6) 41815 * gimple_omp_critical_name: GIMPLE_OMP_CRITICAL. 41816 (line 13) 41817 * gimple_omp_critical_set_name: GIMPLE_OMP_CRITICAL. 41818 (line 21) 41819 * GIMPLE_OMP_FOR: GIMPLE_OMP_FOR. (line 6) 41820 * gimple_omp_for_clauses: GIMPLE_OMP_FOR. (line 20) 41821 * gimple_omp_for_final: GIMPLE_OMP_FOR. (line 51) 41822 * gimple_omp_for_incr: GIMPLE_OMP_FOR. (line 61) 41823 * gimple_omp_for_index: GIMPLE_OMP_FOR. (line 31) 41824 * gimple_omp_for_initial: GIMPLE_OMP_FOR. (line 41) 41825 * gimple_omp_for_pre_body: GIMPLE_OMP_FOR. (line 70) 41826 * gimple_omp_for_set_clauses: GIMPLE_OMP_FOR. (line 27) 41827 * gimple_omp_for_set_cond: GIMPLE_OMP_FOR. (line 80) 41828 * gimple_omp_for_set_final: GIMPLE_OMP_FOR. (line 58) 41829 * gimple_omp_for_set_incr: GIMPLE_OMP_FOR. (line 67) 41830 * gimple_omp_for_set_index: GIMPLE_OMP_FOR. (line 38) 41831 * gimple_omp_for_set_initial: GIMPLE_OMP_FOR. (line 48) 41832 * gimple_omp_for_set_pre_body: GIMPLE_OMP_FOR. (line 75) 41833 * GIMPLE_OMP_MASTER: GIMPLE_OMP_MASTER. (line 6) 41834 * GIMPLE_OMP_ORDERED: GIMPLE_OMP_ORDERED. (line 6) 41835 * GIMPLE_OMP_PARALLEL: GIMPLE_OMP_PARALLEL. 41836 (line 6) 41837 * gimple_omp_parallel_child_fn: GIMPLE_OMP_PARALLEL. 41838 (line 42) 41839 * gimple_omp_parallel_clauses: GIMPLE_OMP_PARALLEL. 41840 (line 31) 41841 * gimple_omp_parallel_combined_p: GIMPLE_OMP_PARALLEL. 41842 (line 16) 41843 * gimple_omp_parallel_data_arg: GIMPLE_OMP_PARALLEL. 41844 (line 54) 41845 * gimple_omp_parallel_set_child_fn: GIMPLE_OMP_PARALLEL. 41846 (line 51) 41847 * gimple_omp_parallel_set_clauses: GIMPLE_OMP_PARALLEL. 41848 (line 38) 41849 * gimple_omp_parallel_set_combined_p: GIMPLE_OMP_PARALLEL. 41850 (line 20) 41851 * gimple_omp_parallel_set_data_arg: GIMPLE_OMP_PARALLEL. 41852 (line 62) 41853 * GIMPLE_OMP_RETURN: GIMPLE_OMP_RETURN. (line 6) 41854 * gimple_omp_return_nowait_p: GIMPLE_OMP_RETURN. (line 14) 41855 * gimple_omp_return_set_nowait: GIMPLE_OMP_RETURN. (line 11) 41856 * GIMPLE_OMP_SECTION: GIMPLE_OMP_SECTION. (line 6) 41857 * gimple_omp_section_last_p: GIMPLE_OMP_SECTION. (line 12) 41858 * gimple_omp_section_set_last: GIMPLE_OMP_SECTION. (line 16) 41859 * GIMPLE_OMP_SECTIONS: GIMPLE_OMP_SECTIONS. 41860 (line 6) 41861 * gimple_omp_sections_clauses: GIMPLE_OMP_SECTIONS. 41862 (line 30) 41863 * gimple_omp_sections_control: GIMPLE_OMP_SECTIONS. 41864 (line 17) 41865 * gimple_omp_sections_set_clauses: GIMPLE_OMP_SECTIONS. 41866 (line 37) 41867 * gimple_omp_sections_set_control: GIMPLE_OMP_SECTIONS. 41868 (line 26) 41869 * gimple_omp_set_body: GIMPLE_OMP_PARALLEL. 41870 (line 28) 41871 * GIMPLE_OMP_SINGLE: GIMPLE_OMP_SINGLE. (line 6) 41872 * gimple_omp_single_clauses: GIMPLE_OMP_SINGLE. (line 14) 41873 * gimple_omp_single_set_clauses: GIMPLE_OMP_SINGLE. (line 21) 41874 * gimple_op <1>: Manipulating GIMPLE statements. 41875 (line 81) 41876 * gimple_op: Logical Operators. (line 79) 41877 * GIMPLE_PHI: GIMPLE_PHI. (line 6) 41878 * gimple_phi_capacity: GIMPLE_PHI. (line 10) 41879 * gimple_phi_num_args: GIMPLE_PHI. (line 14) 41880 * gimple_phi_result: GIMPLE_PHI. (line 19) 41881 * gimple_phi_set_arg: GIMPLE_PHI. (line 33) 41882 * gimple_phi_set_result: GIMPLE_PHI. (line 25) 41883 * GIMPLE_RESX: GIMPLE_RESX. (line 6) 41884 * gimple_resx_region: GIMPLE_RESX. (line 13) 41885 * gimple_resx_set_region: GIMPLE_RESX. (line 16) 41886 * GIMPLE_RETURN: GIMPLE_RETURN. (line 6) 41887 * gimple_return_retval: GIMPLE_RETURN. (line 10) 41888 * gimple_return_set_retval: GIMPLE_RETURN. (line 14) 41889 * gimple_rhs_class: GIMPLE_ASSIGN. (line 46) 41890 * gimple_seq_add_seq: GIMPLE sequences. (line 32) 41891 * gimple_seq_add_stmt: GIMPLE sequences. (line 26) 41892 * gimple_seq_alloc: GIMPLE sequences. (line 62) 41893 * gimple_seq_copy: GIMPLE sequences. (line 67) 41894 * gimple_seq_deep_copy: GIMPLE sequences. (line 37) 41895 * gimple_seq_empty_p: GIMPLE sequences. (line 70) 41896 * gimple_seq_first: GIMPLE sequences. (line 44) 41897 * gimple_seq_init: GIMPLE sequences. (line 59) 41898 * gimple_seq_last: GIMPLE sequences. (line 47) 41899 * gimple_seq_reverse: GIMPLE sequences. (line 40) 41900 * gimple_seq_set_first: GIMPLE sequences. (line 55) 41901 * gimple_seq_set_last: GIMPLE sequences. (line 51) 41902 * gimple_seq_singleton_p: GIMPLE sequences. (line 79) 41903 * gimple_set_block: Manipulating GIMPLE statements. 41904 (line 39) 41905 * gimple_set_def_ops: Manipulating GIMPLE statements. 41906 (line 98) 41907 * gimple_set_has_volatile_ops: Manipulating GIMPLE statements. 41908 (line 138) 41909 * gimple_set_locus: Manipulating GIMPLE statements. 41910 (line 45) 41911 * gimple_set_op: Manipulating GIMPLE statements. 41912 (line 87) 41913 * gimple_set_plf: Manipulating GIMPLE statements. 41914 (line 62) 41915 * gimple_set_use_ops: Manipulating GIMPLE statements. 41916 (line 105) 41917 * gimple_set_vdef_ops: Manipulating GIMPLE statements. 41918 (line 119) 41919 * gimple_set_visited: Manipulating GIMPLE statements. 41920 (line 55) 41921 * gimple_set_vuse_ops: Manipulating GIMPLE statements. 41922 (line 112) 41923 * gimple_statement_base: Tuple representation. 41924 (line 14) 41925 * gimple_statement_with_ops: Tuple representation. 41926 (line 96) 41927 * gimple_stored_syms: Manipulating GIMPLE statements. 41928 (line 126) 41929 * GIMPLE_SWITCH: GIMPLE_SWITCH. (line 6) 41930 * gimple_switch_default_label: GIMPLE_SWITCH. (line 46) 41931 * gimple_switch_index: GIMPLE_SWITCH. (line 31) 41932 * gimple_switch_label: GIMPLE_SWITCH. (line 37) 41933 * gimple_switch_num_labels: GIMPLE_SWITCH. (line 22) 41934 * gimple_switch_set_default_label: GIMPLE_SWITCH. (line 50) 41935 * gimple_switch_set_index: GIMPLE_SWITCH. (line 34) 41936 * gimple_switch_set_label: GIMPLE_SWITCH. (line 42) 41937 * gimple_switch_set_num_labels: GIMPLE_SWITCH. (line 27) 41938 * GIMPLE_TRY: GIMPLE_TRY. (line 6) 41939 * gimple_try_catch_is_cleanup: GIMPLE_TRY. (line 20) 41940 * gimple_try_cleanup: GIMPLE_TRY. (line 27) 41941 * gimple_try_eval: GIMPLE_TRY. (line 23) 41942 * gimple_try_flags: GIMPLE_TRY. (line 16) 41943 * gimple_try_set_catch_is_cleanup: GIMPLE_TRY. (line 32) 41944 * gimple_try_set_cleanup: GIMPLE_TRY. (line 41) 41945 * gimple_try_set_eval: GIMPLE_TRY. (line 36) 41946 * gimple_visited_p: Manipulating GIMPLE statements. 41947 (line 58) 41948 * gimple_wce_cleanup: GIMPLE_WITH_CLEANUP_EXPR. 41949 (line 11) 41950 * gimple_wce_cleanup_eh_only: GIMPLE_WITH_CLEANUP_EXPR. 41951 (line 18) 41952 * gimple_wce_set_cleanup: GIMPLE_WITH_CLEANUP_EXPR. 41953 (line 15) 41954 * gimple_wce_set_cleanup_eh_only: GIMPLE_WITH_CLEANUP_EXPR. 41955 (line 22) 41956 * GIMPLE_WITH_CLEANUP_EXPR: GIMPLE_WITH_CLEANUP_EXPR. 41957 (line 6) 41958 * gimplification <1>: Parsing pass. (line 14) 41959 * gimplification: Gimplification pass. 41960 (line 6) 41961 * gimplifier: Parsing pass. (line 14) 41962 * gimplify_assign: GIMPLE_ASSIGN. (line 19) 41963 * gimplify_expr: Gimplification pass. 41964 (line 18) 41965 * gimplify_function_tree: Gimplification pass. 41966 (line 18) 41967 * GLOBAL_INIT_PRIORITY: Function Basics. (line 6) 41968 * global_regs: Register Basics. (line 59) 41969 * GO_IF_LEGITIMATE_ADDRESS: Addressing Modes. (line 48) 41970 * GO_IF_MODE_DEPENDENT_ADDRESS: Addressing Modes. (line 190) 41971 * GOFAST, floating point emulation library: Library Calls. (line 44) 41972 * gofast_maybe_init_libfuncs: Library Calls. (line 44) 41973 * greater than: Comparisons. (line 64) 41974 * gsi_after_labels: Sequence iterators. (line 76) 41975 * gsi_bb: Sequence iterators. (line 83) 41976 * gsi_commit_edge_inserts: Sequence iterators. (line 194) 41977 * gsi_commit_one_edge_insert: Sequence iterators. (line 190) 41978 * gsi_end_p: Sequence iterators. (line 60) 41979 * gsi_for_stmt: Sequence iterators. (line 157) 41980 * gsi_insert_after: Sequence iterators. (line 147) 41981 * gsi_insert_before: Sequence iterators. (line 136) 41982 * gsi_insert_on_edge: Sequence iterators. (line 174) 41983 * gsi_insert_on_edge_immediate: Sequence iterators. (line 185) 41984 * gsi_insert_seq_after: Sequence iterators. (line 154) 41985 * gsi_insert_seq_before: Sequence iterators. (line 143) 41986 * gsi_insert_seq_on_edge: Sequence iterators. (line 179) 41987 * gsi_last: Sequence iterators. (line 50) 41988 * gsi_last_bb: Sequence iterators. (line 56) 41989 * gsi_link_after: Sequence iterators. (line 115) 41990 * gsi_link_before: Sequence iterators. (line 105) 41991 * gsi_link_seq_after: Sequence iterators. (line 110) 41992 * gsi_link_seq_before: Sequence iterators. (line 99) 41993 * gsi_move_after: Sequence iterators. (line 161) 41994 * gsi_move_before: Sequence iterators. (line 166) 41995 * gsi_move_to_bb_end: Sequence iterators. (line 171) 41996 * gsi_next: Sequence iterators. (line 66) 41997 * gsi_one_before_end_p: Sequence iterators. (line 63) 41998 * gsi_prev: Sequence iterators. (line 69) 41999 * gsi_remove: Sequence iterators. (line 90) 42000 * gsi_replace: Sequence iterators. (line 130) 42001 * gsi_seq: Sequence iterators. (line 86) 42002 * gsi_split_seq_after: Sequence iterators. (line 120) 42003 * gsi_split_seq_before: Sequence iterators. (line 125) 42004 * gsi_start: Sequence iterators. (line 40) 42005 * gsi_start_bb: Sequence iterators. (line 46) 42006 * gsi_stmt: Sequence iterators. (line 72) 42007 * gt: Comparisons. (line 60) 42008 * gt and attributes: Expressions. (line 64) 42009 * GT_EXPR: Expression trees. (line 6) 42010 * gtu: Comparisons. (line 64) 42011 * gtu and attributes: Expressions. (line 64) 42012 * GTY: Type Information. (line 6) 42013 * H in constraint: Simple Constraints. (line 88) 42014 * HAmode: Machine Modes. (line 144) 42015 * HANDLE_PRAGMA_PACK_PUSH_POP: Misc. (line 467) 42016 * HANDLE_PRAGMA_PACK_WITH_EXPANSION: Misc. (line 478) 42017 * HANDLE_PRAGMA_PUSH_POP_MACRO: Misc. (line 488) 42018 * HANDLE_SYSV_PRAGMA: Misc. (line 438) 42019 * HANDLER: Function Bodies. (line 6) 42020 * HANDLER_BODY: Function Bodies. (line 6) 42021 * HANDLER_PARMS: Function Bodies. (line 6) 42022 * hard registers: Regs and Memory. (line 9) 42023 * HARD_FRAME_POINTER_REGNUM: Frame Registers. (line 20) 42024 * HARD_REGNO_CALL_PART_CLOBBERED: Register Basics. (line 53) 42025 * HARD_REGNO_CALLER_SAVE_MODE: Caller Saves. (line 20) 42026 * HARD_REGNO_MODE_OK: Values in Registers. 42027 (line 58) 42028 * HARD_REGNO_NREGS: Values in Registers. 42029 (line 11) 42030 * HARD_REGNO_NREGS_HAS_PADDING: Values in Registers. 42031 (line 25) 42032 * HARD_REGNO_NREGS_WITH_PADDING: Values in Registers. 42033 (line 43) 42034 * HARD_REGNO_RENAME_OK: Values in Registers. 42035 (line 119) 42036 * HAS_INIT_SECTION: Macros for Initialization. 42037 (line 19) 42038 * HAS_LONG_COND_BRANCH: Misc. (line 9) 42039 * HAS_LONG_UNCOND_BRANCH: Misc. (line 18) 42040 * HAVE_DOS_BASED_FILE_SYSTEM: Filesystem. (line 11) 42041 * HAVE_POST_DECREMENT: Addressing Modes. (line 12) 42042 * HAVE_POST_INCREMENT: Addressing Modes. (line 11) 42043 * HAVE_POST_MODIFY_DISP: Addressing Modes. (line 18) 42044 * HAVE_POST_MODIFY_REG: Addressing Modes. (line 24) 42045 * HAVE_PRE_DECREMENT: Addressing Modes. (line 10) 42046 * HAVE_PRE_INCREMENT: Addressing Modes. (line 9) 42047 * HAVE_PRE_MODIFY_DISP: Addressing Modes. (line 17) 42048 * HAVE_PRE_MODIFY_REG: Addressing Modes. (line 23) 42049 * HCmode: Machine Modes. (line 197) 42050 * HFmode: Machine Modes. (line 58) 42051 * high: Constants. (line 109) 42052 * HImode: Machine Modes. (line 29) 42053 * HImode, in insn: Insns. (line 231) 42054 * host configuration: Host Config. (line 6) 42055 * host functions: Host Common. (line 6) 42056 * host hooks: Host Common. (line 6) 42057 * host makefile fragment: Host Fragment. (line 6) 42058 * HOST_BIT_BUCKET: Filesystem. (line 51) 42059 * HOST_EXECUTABLE_SUFFIX: Filesystem. (line 45) 42060 * HOST_HOOKS_EXTRA_SIGNALS: Host Common. (line 12) 42061 * HOST_HOOKS_GT_PCH_ALLOC_GRANULARITY: Host Common. (line 45) 42062 * HOST_HOOKS_GT_PCH_USE_ADDRESS: Host Common. (line 26) 42063 * HOST_LACKS_INODE_NUMBERS: Filesystem. (line 89) 42064 * HOST_LONG_LONG_FORMAT: Host Misc. (line 41) 42065 * HOST_OBJECT_SUFFIX: Filesystem. (line 40) 42066 * HOST_WIDE_INT: Anchored Addresses. (line 33) 42067 * HOT_TEXT_SECTION_NAME: Sections. (line 43) 42068 * HQmode: Machine Modes. (line 107) 42069 * I in constraint: Simple Constraints. (line 71) 42070 * i in constraint: Simple Constraints. (line 60) 42071 * identifier: Identifiers. (line 6) 42072 * IDENTIFIER_LENGTH: Identifiers. (line 20) 42073 * IDENTIFIER_NODE: Identifiers. (line 6) 42074 * IDENTIFIER_OPNAME_P: Identifiers. (line 25) 42075 * IDENTIFIER_POINTER: Identifiers. (line 15) 42076 * IDENTIFIER_TYPENAME_P: Identifiers. (line 31) 42077 * IEEE 754-2008: Decimal float library routines. 42078 (line 6) 42079 * IF_COND: Function Bodies. (line 6) 42080 * if_marked: GTY Options. (line 156) 42081 * IF_STMT: Function Bodies. (line 6) 42082 * if_then_else: Comparisons. (line 80) 42083 * if_then_else and attributes: Expressions. (line 32) 42084 * if_then_else usage: Side Effects. (line 56) 42085 * IFCVT_EXTRA_FIELDS: Misc. (line 627) 42086 * IFCVT_INIT_EXTRA_FIELDS: Misc. (line 622) 42087 * IFCVT_MODIFY_CANCEL: Misc. (line 616) 42088 * IFCVT_MODIFY_FINAL: Misc. (line 610) 42089 * IFCVT_MODIFY_INSN: Misc. (line 604) 42090 * IFCVT_MODIFY_MULTIPLE_TESTS: Misc. (line 597) 42091 * IFCVT_MODIFY_TESTS: Misc. (line 586) 42092 * IMAGPART_EXPR: Expression trees. (line 6) 42093 * Immediate Uses: SSA Operands. (line 274) 42094 * immediate_operand: Machine-Independent Predicates. 42095 (line 11) 42096 * IMMEDIATE_PREFIX: Instruction Output. (line 127) 42097 * in_struct: Flags. (line 258) 42098 * in_struct, in code_label and note: Flags. (line 59) 42099 * in_struct, in insn and jump_insn and call_insn: Flags. (line 49) 42100 * in_struct, in insn, jump_insn and call_insn: Flags. (line 166) 42101 * in_struct, in mem: Flags. (line 70) 42102 * in_struct, in subreg: Flags. (line 205) 42103 * include: Including Patterns. (line 6) 42104 * INCLUDE_DEFAULTS: Driver. (line 430) 42105 * inclusive-or, bitwise: Arithmetic. (line 158) 42106 * INCOMING_FRAME_SP_OFFSET: Frame Layout. (line 183) 42107 * INCOMING_REGNO: Register Basics. (line 91) 42108 * INCOMING_RETURN_ADDR_RTX: Frame Layout. (line 139) 42109 * INCOMING_STACK_BOUNDARY: Storage Layout. (line 165) 42110 * INDEX_REG_CLASS: Register Classes. (line 134) 42111 * indirect_jump instruction pattern: Standard Names. (line 1078) 42112 * indirect_operand: Machine-Independent Predicates. 42113 (line 71) 42114 * INDIRECT_REF: Expression trees. (line 6) 42115 * INIT_ARRAY_SECTION_ASM_OP: Sections. (line 98) 42116 * INIT_CUMULATIVE_ARGS: Register Arguments. (line 149) 42117 * INIT_CUMULATIVE_INCOMING_ARGS: Register Arguments. (line 177) 42118 * INIT_CUMULATIVE_LIBCALL_ARGS: Register Arguments. (line 170) 42119 * INIT_ENVIRONMENT: Driver. (line 369) 42120 * INIT_EXPANDERS: Per-Function Data. (line 39) 42121 * INIT_EXPR: Expression trees. (line 6) 42122 * init_machine_status: Per-Function Data. (line 45) 42123 * init_one_libfunc: Library Calls. (line 15) 42124 * INIT_SECTION_ASM_OP <1>: Sections. (line 82) 42125 * INIT_SECTION_ASM_OP: Macros for Initialization. 42126 (line 10) 42127 * INITIAL_ELIMINATION_OFFSET: Elimination. (line 79) 42128 * INITIAL_FRAME_ADDRESS_RTX: Frame Layout. (line 83) 42129 * INITIAL_FRAME_POINTER_OFFSET: Elimination. (line 32) 42130 * initialization routines: Initialization. (line 6) 42131 * INITIALIZE_TRAMPOLINE: Trampolines. (line 55) 42132 * inlining: Target Attributes. (line 86) 42133 * insert_insn_on_edge: Maintaining the CFG. 42134 (line 118) 42135 * insn: Insns. (line 63) 42136 * insn and /f: Flags. (line 125) 42137 * insn and /j: Flags. (line 175) 42138 * insn and /s: Flags. (line 166) 42139 * insn and /u: Flags. (line 39) 42140 * insn and /v: Flags. (line 44) 42141 * insn attributes: Insn Attributes. (line 6) 42142 * insn canonicalization: Insn Canonicalizations. 42143 (line 6) 42144 * insn includes: Including Patterns. (line 6) 42145 * insn lengths, computing: Insn Lengths. (line 6) 42146 * insn splitting: Insn Splitting. (line 6) 42147 * insn-attr.h: Defining Attributes. 42148 (line 24) 42149 * INSN_ANNULLED_BRANCH_P: Flags. (line 39) 42150 * INSN_CODE: Insns. (line 257) 42151 * INSN_DELETED_P: Flags. (line 44) 42152 * INSN_FROM_TARGET_P: Flags. (line 49) 42153 * insn_list: Insns. (line 505) 42154 * INSN_REFERENCES_ARE_DELAYED: Misc. (line 525) 42155 * INSN_SETS_ARE_DELAYED: Misc. (line 514) 42156 * INSN_UID: Insns. (line 23) 42157 * insns: Insns. (line 6) 42158 * insns, generating: RTL Template. (line 6) 42159 * insns, recognizing: RTL Template. (line 6) 42160 * instruction attributes: Insn Attributes. (line 6) 42161 * instruction latency time: Processor pipeline description. 42162 (line 106) 42163 * instruction patterns: Patterns. (line 6) 42164 * instruction splitting: Insn Splitting. (line 6) 42165 * insv instruction pattern: Standard Names. (line 880) 42166 * int <1>: Run-time Target. (line 56) 42167 * int: Manipulating GIMPLE statements. 42168 (line 66) 42169 * INT_TYPE_SIZE: Type Layout. (line 12) 42170 * INTEGER_CST: Expression trees. (line 6) 42171 * INTEGER_TYPE: Types. (line 6) 42172 * Interdependence of Patterns: Dependent Patterns. (line 6) 42173 * interfacing to GCC output: Interface. (line 6) 42174 * interlock delays: Processor pipeline description. 42175 (line 6) 42176 * intermediate representation lowering: Parsing pass. (line 14) 42177 * INTMAX_TYPE: Type Layout. (line 213) 42178 * introduction: Top. (line 6) 42179 * INVOKE__main: Macros for Initialization. 42180 (line 51) 42181 * ior: Arithmetic. (line 158) 42182 * ior and attributes: Expressions. (line 50) 42183 * ior, canonicalization of: Insn Canonicalizations. 42184 (line 57) 42185 * iorM3 instruction pattern: Standard Names. (line 222) 42186 * IRA_COVER_CLASSES: Register Classes. (line 516) 42187 * IRA_HARD_REGNO_ADD_COST_MULTIPLIER: Allocation Order. (line 37) 42188 * IS_ASM_LOGICAL_LINE_SEPARATOR: Data Output. (line 120) 42189 * is_gimple_omp: GIMPLE_OMP_PARALLEL. 42190 (line 65) 42191 * iterators in .md files: Iterators. (line 6) 42192 * IV analysis on GIMPLE: Scalar evolutions. (line 6) 42193 * IV analysis on RTL: loop-iv. (line 6) 42194 * jump: Flags. (line 309) 42195 * jump instruction pattern: Standard Names. (line 969) 42196 * jump instruction patterns: Jump Patterns. (line 6) 42197 * jump instructions and set: Side Effects. (line 56) 42198 * jump, in call_insn: Flags. (line 179) 42199 * jump, in insn: Flags. (line 175) 42200 * jump, in mem: Flags. (line 79) 42201 * JUMP_ALIGN: Alignment Output. (line 9) 42202 * jump_insn: Insns. (line 73) 42203 * jump_insn and /f: Flags. (line 125) 42204 * jump_insn and /s: Flags. (line 49) 42205 * jump_insn and /u: Flags. (line 39) 42206 * jump_insn and /v: Flags. (line 44) 42207 * JUMP_LABEL: Insns. (line 80) 42208 * JUMP_TABLES_IN_TEXT_SECTION: Sections. (line 142) 42209 * Jumps: Jumps. (line 6) 42210 * LABEL_ALIGN: Alignment Output. (line 52) 42211 * LABEL_ALIGN_AFTER_BARRIER: Alignment Output. (line 22) 42212 * LABEL_ALIGN_AFTER_BARRIER_MAX_SKIP: Alignment Output. (line 30) 42213 * LABEL_ALIGN_MAX_SKIP: Alignment Output. (line 62) 42214 * LABEL_ALT_ENTRY_P: Insns. (line 140) 42215 * LABEL_ALTERNATE_NAME: Edges. (line 180) 42216 * LABEL_DECL: Declarations. (line 6) 42217 * LABEL_KIND: Insns. (line 140) 42218 * LABEL_NUSES: Insns. (line 136) 42219 * LABEL_PRESERVE_P: Flags. (line 59) 42220 * label_ref: Constants. (line 86) 42221 * label_ref and /v: Flags. (line 65) 42222 * label_ref, RTL sharing: Sharing. (line 35) 42223 * LABEL_REF_NONLOCAL_P: Flags. (line 65) 42224 * lang_hooks.gimplify_expr: Gimplification pass. 42225 (line 18) 42226 * lang_hooks.parse_file: Parsing pass. (line 6) 42227 * language-independent intermediate representation: Parsing pass. 42228 (line 14) 42229 * large return values: Aggregate Return. (line 6) 42230 * LARGEST_EXPONENT_IS_NORMAL: Storage Layout. (line 469) 42231 * LAST_STACK_REG: Stack Registers. (line 27) 42232 * LAST_VIRTUAL_REGISTER: Regs and Memory. (line 51) 42233 * lceilMN2: Standard Names. (line 597) 42234 * LCSSA: LCSSA. (line 6) 42235 * LD_FINI_SWITCH: Macros for Initialization. 42236 (line 29) 42237 * LD_INIT_SWITCH: Macros for Initialization. 42238 (line 25) 42239 * LDD_SUFFIX: Macros for Initialization. 42240 (line 116) 42241 * le: Comparisons. (line 76) 42242 * le and attributes: Expressions. (line 64) 42243 * LE_EXPR: Expression trees. (line 6) 42244 * leaf functions: Leaf Functions. (line 6) 42245 * leaf_function_p: Standard Names. (line 1040) 42246 * LEAF_REG_REMAP: Leaf Functions. (line 39) 42247 * LEAF_REGISTERS: Leaf Functions. (line 25) 42248 * left rotate: Arithmetic. (line 190) 42249 * left shift: Arithmetic. (line 168) 42250 * LEGITIMATE_CONSTANT_P: Addressing Modes. (line 205) 42251 * LEGITIMATE_PIC_OPERAND_P: PIC. (line 31) 42252 * LEGITIMIZE_ADDRESS: Addressing Modes. (line 122) 42253 * LEGITIMIZE_RELOAD_ADDRESS: Addressing Modes. (line 145) 42254 * length: GTY Options. (line 50) 42255 * less than: Comparisons. (line 68) 42256 * less than or equal: Comparisons. (line 76) 42257 * leu: Comparisons. (line 76) 42258 * leu and attributes: Expressions. (line 64) 42259 * lfloorMN2: Standard Names. (line 592) 42260 * LIB2FUNCS_EXTRA: Target Fragment. (line 11) 42261 * LIB_SPEC: Driver. (line 170) 42262 * LIBCALL_VALUE: Scalar Return. (line 60) 42263 * libgcc.a: Library Calls. (line 6) 42264 * LIBGCC2_CFLAGS: Target Fragment. (line 8) 42265 * LIBGCC2_HAS_DF_MODE: Type Layout. (line 109) 42266 * LIBGCC2_HAS_TF_MODE: Type Layout. (line 123) 42267 * LIBGCC2_HAS_XF_MODE: Type Layout. (line 117) 42268 * LIBGCC2_LONG_DOUBLE_TYPE_SIZE: Type Layout. (line 103) 42269 * LIBGCC2_UNWIND_ATTRIBUTE: Misc. (line 943) 42270 * LIBGCC2_WORDS_BIG_ENDIAN: Storage Layout. (line 36) 42271 * LIBGCC_SPEC: Driver. (line 178) 42272 * library subroutine names: Library Calls. (line 6) 42273 * LIBRARY_PATH_ENV: Misc. (line 565) 42274 * LIMIT_RELOAD_CLASS: Register Classes. (line 239) 42275 * Linear loop transformations framework: Lambda. (line 6) 42276 * LINK_COMMAND_SPEC: Driver. (line 299) 42277 * LINK_EH_SPEC: Driver. (line 205) 42278 * LINK_ELIMINATE_DUPLICATE_LDIRECTORIES: Driver. (line 309) 42279 * LINK_GCC_C_SEQUENCE_SPEC: Driver. (line 295) 42280 * LINK_LIBGCC_SPECIAL_1: Driver. (line 290) 42281 * LINK_SPEC: Driver. (line 163) 42282 * linkage: Function Basics. (line 6) 42283 * list: Containers. (line 6) 42284 * Liveness representation: Liveness information. 42285 (line 6) 42286 * lo_sum: Arithmetic. (line 24) 42287 * load address instruction: Simple Constraints. (line 154) 42288 * LOAD_EXTEND_OP: Misc. (line 69) 42289 * load_multiple instruction pattern: Standard Names. (line 137) 42290 * LOCAL_ALIGNMENT: Storage Layout. (line 254) 42291 * LOCAL_CLASS_P: Classes. (line 68) 42292 * LOCAL_DECL_ALIGNMENT: Storage Layout. (line 278) 42293 * LOCAL_INCLUDE_DIR: Driver. (line 376) 42294 * LOCAL_LABEL_PREFIX: Instruction Output. (line 125) 42295 * LOCAL_REGNO: Register Basics. (line 105) 42296 * LOG_LINKS: Insns. (line 276) 42297 * Logical Operators: Logical Operators. (line 6) 42298 * logical-and, bitwise: Arithmetic. (line 153) 42299 * logM2 instruction pattern: Standard Names. (line 505) 42300 * LONG_ACCUM_TYPE_SIZE: Type Layout. (line 93) 42301 * LONG_DOUBLE_TYPE_SIZE: Type Layout. (line 58) 42302 * LONG_FRACT_TYPE_SIZE: Type Layout. (line 73) 42303 * LONG_LONG_ACCUM_TYPE_SIZE: Type Layout. (line 98) 42304 * LONG_LONG_FRACT_TYPE_SIZE: Type Layout. (line 78) 42305 * LONG_LONG_TYPE_SIZE: Type Layout. (line 33) 42306 * LONG_TYPE_SIZE: Type Layout. (line 22) 42307 * longjmp and automatic variables: Interface. (line 52) 42308 * Loop analysis: Loop representation. 42309 (line 6) 42310 * Loop manipulation: Loop manipulation. (line 6) 42311 * Loop querying: Loop querying. (line 6) 42312 * Loop representation: Loop representation. 42313 (line 6) 42314 * Loop-closed SSA form: LCSSA. (line 6) 42315 * LOOP_ALIGN: Alignment Output. (line 35) 42316 * LOOP_ALIGN_MAX_SKIP: Alignment Output. (line 48) 42317 * LOOP_EXPR: Expression trees. (line 6) 42318 * looping instruction patterns: Looping Patterns. (line 6) 42319 * lowering, language-dependent intermediate representation: Parsing pass. 42320 (line 14) 42321 * lrintMN2: Standard Names. (line 582) 42322 * lroundMN2: Standard Names. (line 587) 42323 * LSHIFT_EXPR: Expression trees. (line 6) 42324 * lshiftrt: Arithmetic. (line 185) 42325 * lshiftrt and attributes: Expressions. (line 64) 42326 * lshrM3 instruction pattern: Standard Names. (line 441) 42327 * lt: Comparisons. (line 68) 42328 * lt and attributes: Expressions. (line 64) 42329 * LT_EXPR: Expression trees. (line 6) 42330 * LTGT_EXPR: Expression trees. (line 6) 42331 * ltu: Comparisons. (line 68) 42332 * m in constraint: Simple Constraints. (line 17) 42333 * machine attributes: Target Attributes. (line 6) 42334 * machine description macros: Target Macros. (line 6) 42335 * machine descriptions: Machine Desc. (line 6) 42336 * machine mode conversions: Conversions. (line 6) 42337 * machine modes: Machine Modes. (line 6) 42338 * machine specific constraints: Machine Constraints. 42339 (line 6) 42340 * machine-independent predicates: Machine-Independent Predicates. 42341 (line 6) 42342 * machine_mode: Condition Code. (line 157) 42343 * macros, target description: Target Macros. (line 6) 42344 * maddMN4 instruction pattern: Standard Names. (line 364) 42345 * MAKE_DECL_ONE_ONLY: Label Output. (line 218) 42346 * make_phi_node: GIMPLE_PHI. (line 7) 42347 * make_safe_from: Expander Definitions. 42348 (line 148) 42349 * makefile fragment: Fragments. (line 6) 42350 * makefile targets: Makefile. (line 6) 42351 * MALLOC_ABI_ALIGNMENT: Storage Layout. (line 179) 42352 * Manipulating GIMPLE statements: Manipulating GIMPLE statements. 42353 (line 6) 42354 * mark_hook: GTY Options. (line 171) 42355 * marking roots: GGC Roots. (line 6) 42356 * MASK_RETURN_ADDR: Exception Region Output. 42357 (line 35) 42358 * match_dup <1>: define_peephole2. (line 28) 42359 * match_dup: RTL Template. (line 73) 42360 * match_dup and attributes: Insn Lengths. (line 16) 42361 * match_op_dup: RTL Template. (line 163) 42362 * match_operand: RTL Template. (line 16) 42363 * match_operand and attributes: Expressions. (line 55) 42364 * match_operator: RTL Template. (line 95) 42365 * match_par_dup: RTL Template. (line 219) 42366 * match_parallel: RTL Template. (line 172) 42367 * match_scratch <1>: RTL Template. (line 58) 42368 * match_scratch: define_peephole2. (line 28) 42369 * matching constraint: Simple Constraints. (line 132) 42370 * matching operands: Output Template. (line 49) 42371 * math library: Soft float library routines. 42372 (line 6) 42373 * math, in RTL: Arithmetic. (line 6) 42374 * MATH_LIBRARY: Misc. (line 558) 42375 * matherr: Library Calls. (line 58) 42376 * MAX_BITS_PER_WORD: Storage Layout. (line 61) 42377 * MAX_CONDITIONAL_EXECUTE: Misc. (line 580) 42378 * MAX_FIXED_MODE_SIZE: Storage Layout. (line 420) 42379 * MAX_MOVE_MAX: Misc. (line 120) 42380 * MAX_OFILE_ALIGNMENT: Storage Layout. (line 216) 42381 * MAX_REGS_PER_ADDRESS: Addressing Modes. (line 42) 42382 * MAX_STACK_ALIGNMENT: Storage Layout. (line 209) 42383 * maxM3 instruction pattern: Standard Names. (line 234) 42384 * may_trap_p, tree_could_trap_p: Edges. (line 115) 42385 * maybe_undef: GTY Options. (line 179) 42386 * mcount: Profiling. (line 12) 42387 * MD_CAN_REDIRECT_BRANCH: Misc. (line 705) 42388 * MD_EXEC_PREFIX: Driver. (line 330) 42389 * MD_FALLBACK_FRAME_STATE_FOR: Exception Handling. (line 98) 42390 * MD_HANDLE_UNWABI: Exception Handling. (line 118) 42391 * MD_STARTFILE_PREFIX: Driver. (line 358) 42392 * MD_STARTFILE_PREFIX_1: Driver. (line 364) 42393 * MD_UNWIND_SUPPORT: Exception Handling. (line 94) 42394 * mem: Regs and Memory. (line 374) 42395 * mem and /c: Flags. (line 99) 42396 * mem and /f: Flags. (line 103) 42397 * mem and /i: Flags. (line 85) 42398 * mem and /j: Flags. (line 79) 42399 * mem and /s: Flags. (line 70) 42400 * mem and /u: Flags. (line 152) 42401 * mem and /v: Flags. (line 94) 42402 * mem, RTL sharing: Sharing. (line 40) 42403 * MEM_ALIAS_SET: Special Accessors. (line 9) 42404 * MEM_ALIGN: Special Accessors. (line 36) 42405 * MEM_EXPR: Special Accessors. (line 20) 42406 * MEM_IN_STRUCT_P: Flags. (line 70) 42407 * MEM_KEEP_ALIAS_SET_P: Flags. (line 79) 42408 * MEM_NOTRAP_P: Flags. (line 99) 42409 * MEM_OFFSET: Special Accessors. (line 28) 42410 * MEM_POINTER: Flags. (line 103) 42411 * MEM_READONLY_P: Flags. (line 152) 42412 * MEM_SCALAR_P: Flags. (line 85) 42413 * MEM_SIZE: Special Accessors. (line 31) 42414 * MEM_VOLATILE_P: Flags. (line 94) 42415 * MEMBER_TYPE_FORCES_BLK: Storage Layout. (line 400) 42416 * memory reference, nonoffsettable: Simple Constraints. (line 246) 42417 * memory references in constraints: Simple Constraints. (line 17) 42418 * memory_barrier instruction pattern: Standard Names. (line 1413) 42419 * MEMORY_MOVE_COST: Costs. (line 29) 42420 * memory_operand: Machine-Independent Predicates. 42421 (line 58) 42422 * METHOD_TYPE: Types. (line 6) 42423 * MIN_UNITS_PER_WORD: Storage Layout. (line 71) 42424 * MINIMUM_ALIGNMENT: Storage Layout. (line 288) 42425 * MINIMUM_ATOMIC_ALIGNMENT: Storage Layout. (line 187) 42426 * minM3 instruction pattern: Standard Names. (line 234) 42427 * minus: Arithmetic. (line 36) 42428 * minus and attributes: Expressions. (line 64) 42429 * minus, canonicalization of: Insn Canonicalizations. 42430 (line 27) 42431 * MINUS_EXPR: Expression trees. (line 6) 42432 * MIPS coprocessor-definition macros: MIPS Coprocessors. (line 6) 42433 * mod: Arithmetic. (line 131) 42434 * mod and attributes: Expressions. (line 64) 42435 * mode classes: Machine Modes. (line 219) 42436 * mode iterators in .md files: Mode Iterators. (line 6) 42437 * mode switching: Mode Switching. (line 6) 42438 * MODE_ACCUM: Machine Modes. (line 249) 42439 * MODE_AFTER: Mode Switching. (line 49) 42440 * MODE_BASE_REG_CLASS: Register Classes. (line 112) 42441 * MODE_BASE_REG_REG_CLASS: Register Classes. (line 118) 42442 * MODE_CC: Machine Modes. (line 268) 42443 * MODE_CODE_BASE_REG_CLASS: Register Classes. (line 125) 42444 * MODE_COMPLEX_FLOAT: Machine Modes. (line 260) 42445 * MODE_COMPLEX_INT: Machine Modes. (line 257) 42446 * MODE_DECIMAL_FLOAT: Machine Modes. (line 237) 42447 * MODE_ENTRY: Mode Switching. (line 54) 42448 * MODE_EXIT: Mode Switching. (line 60) 42449 * MODE_FLOAT: Machine Modes. (line 233) 42450 * MODE_FRACT: Machine Modes. (line 241) 42451 * MODE_FUNCTION: Machine Modes. (line 264) 42452 * MODE_INT: Machine Modes. (line 225) 42453 * MODE_NEEDED: Mode Switching. (line 42) 42454 * MODE_PARTIAL_INT: Machine Modes. (line 229) 42455 * MODE_PRIORITY_TO_MODE: Mode Switching. (line 66) 42456 * MODE_RANDOM: Machine Modes. (line 273) 42457 * MODE_UACCUM: Machine Modes. (line 253) 42458 * MODE_UFRACT: Machine Modes. (line 245) 42459 * MODES_TIEABLE_P: Values in Registers. 42460 (line 129) 42461 * modifiers in constraints: Modifiers. (line 6) 42462 * MODIFY_EXPR: Expression trees. (line 6) 42463 * MODIFY_JNI_METHOD_CALL: Misc. (line 782) 42464 * MODIFY_TARGET_NAME: Driver. (line 385) 42465 * modM3 instruction pattern: Standard Names. (line 222) 42466 * modulo scheduling: RTL passes. (line 140) 42467 * MOVE_BY_PIECES_P: Costs. (line 110) 42468 * MOVE_MAX: Misc. (line 115) 42469 * MOVE_MAX_PIECES: Costs. (line 116) 42470 * MOVE_RATIO: Costs. (line 97) 42471 * movM instruction pattern: Standard Names. (line 11) 42472 * movmemM instruction pattern: Standard Names. (line 672) 42473 * movmisalignM instruction pattern: Standard Names. (line 126) 42474 * movMODEcc instruction pattern: Standard Names. (line 891) 42475 * movstr instruction pattern: Standard Names. (line 707) 42476 * movstrictM instruction pattern: Standard Names. (line 120) 42477 * msubMN4 instruction pattern: Standard Names. (line 387) 42478 * mulhisi3 instruction pattern: Standard Names. (line 340) 42479 * mulM3 instruction pattern: Standard Names. (line 222) 42480 * mulqihi3 instruction pattern: Standard Names. (line 344) 42481 * mulsidi3 instruction pattern: Standard Names. (line 344) 42482 * mult: Arithmetic. (line 92) 42483 * mult and attributes: Expressions. (line 64) 42484 * mult, canonicalization of: Insn Canonicalizations. 42485 (line 27) 42486 * MULT_EXPR: Expression trees. (line 6) 42487 * MULTILIB_DEFAULTS: Driver. (line 315) 42488 * MULTILIB_DIRNAMES: Target Fragment. (line 64) 42489 * MULTILIB_EXCEPTIONS: Target Fragment. (line 84) 42490 * MULTILIB_EXTRA_OPTS: Target Fragment. (line 96) 42491 * MULTILIB_MATCHES: Target Fragment. (line 77) 42492 * MULTILIB_OPTIONS: Target Fragment. (line 44) 42493 * multiple alternative constraints: Multi-Alternative. (line 6) 42494 * MULTIPLE_SYMBOL_SPACES: Misc. (line 538) 42495 * multiplication: Arithmetic. (line 92) 42496 * multiplication with signed saturation: Arithmetic. (line 92) 42497 * multiplication with unsigned saturation: Arithmetic. (line 92) 42498 * MUST_USE_SJLJ_EXCEPTIONS: Exception Region Output. 42499 (line 64) 42500 * n in constraint: Simple Constraints. (line 65) 42501 * N_REG_CLASSES: Register Classes. (line 76) 42502 * name: Identifiers. (line 6) 42503 * named patterns and conditions: Patterns. (line 47) 42504 * names, pattern: Standard Names. (line 6) 42505 * namespace: Namespaces. (line 6) 42506 * namespace, class, scope: Scopes. (line 6) 42507 * NAMESPACE_DECL <1>: Namespaces. (line 6) 42508 * NAMESPACE_DECL: Declarations. (line 6) 42509 * NATIVE_SYSTEM_HEADER_DIR: Target Fragment. (line 103) 42510 * ne: Comparisons. (line 56) 42511 * ne and attributes: Expressions. (line 64) 42512 * NE_EXPR: Expression trees. (line 6) 42513 * nearbyintM2 instruction pattern: Standard Names. (line 564) 42514 * neg: Arithmetic. (line 81) 42515 * neg and attributes: Expressions. (line 64) 42516 * neg, canonicalization of: Insn Canonicalizations. 42517 (line 27) 42518 * NEGATE_EXPR: Expression trees. (line 6) 42519 * negation: Arithmetic. (line 81) 42520 * negation with signed saturation: Arithmetic. (line 81) 42521 * negation with unsigned saturation: Arithmetic. (line 81) 42522 * negM2 instruction pattern: Standard Names. (line 449) 42523 * nested functions, trampolines for: Trampolines. (line 6) 42524 * nested_ptr: GTY Options. (line 186) 42525 * next_bb, prev_bb, FOR_EACH_BB: Basic Blocks. (line 10) 42526 * next_cc0_user: Jump Patterns. (line 64) 42527 * NEXT_INSN: Insns. (line 30) 42528 * NEXT_OBJC_RUNTIME: Library Calls. (line 94) 42529 * nil: RTL Objects. (line 73) 42530 * NO_DBX_BNSYM_ENSYM: DBX Hooks. (line 39) 42531 * NO_DBX_FUNCTION_END: DBX Hooks. (line 33) 42532 * NO_DBX_GCC_MARKER: File Names and DBX. (line 28) 42533 * NO_DBX_MAIN_SOURCE_DIRECTORY: File Names and DBX. (line 23) 42534 * NO_DOLLAR_IN_LABEL: Misc. (line 502) 42535 * NO_DOT_IN_LABEL: Misc. (line 508) 42536 * NO_FUNCTION_CSE: Costs. (line 200) 42537 * NO_IMPLICIT_EXTERN_C: Misc. (line 376) 42538 * NO_PROFILE_COUNTERS: Profiling. (line 28) 42539 * NO_REGS: Register Classes. (line 17) 42540 * NON_LVALUE_EXPR: Expression trees. (line 6) 42541 * nondeterministic finite state automaton: Processor pipeline description. 42542 (line 296) 42543 * nonimmediate_operand: Machine-Independent Predicates. 42544 (line 101) 42545 * nonlocal goto handler: Edges. (line 171) 42546 * nonlocal_goto instruction pattern: Standard Names. (line 1255) 42547 * nonlocal_goto_receiver instruction pattern: Standard Names. 42548 (line 1272) 42549 * nonmemory_operand: Machine-Independent Predicates. 42550 (line 97) 42551 * nonoffsettable memory reference: Simple Constraints. (line 246) 42552 * nop instruction pattern: Standard Names. (line 1073) 42553 * NOP_EXPR: Expression trees. (line 6) 42554 * normal predicates: Predicates. (line 31) 42555 * not: Arithmetic. (line 149) 42556 * not and attributes: Expressions. (line 50) 42557 * not equal: Comparisons. (line 56) 42558 * not, canonicalization of: Insn Canonicalizations. 42559 (line 27) 42560 * note: Insns. (line 168) 42561 * note and /i: Flags. (line 59) 42562 * note and /v: Flags. (line 44) 42563 * NOTE_INSN_BASIC_BLOCK, CODE_LABEL, notes: Basic Blocks. (line 41) 42564 * NOTE_INSN_BLOCK_BEG: Insns. (line 193) 42565 * NOTE_INSN_BLOCK_END: Insns. (line 193) 42566 * NOTE_INSN_DELETED: Insns. (line 183) 42567 * NOTE_INSN_DELETED_LABEL: Insns. (line 188) 42568 * NOTE_INSN_EH_REGION_BEG: Insns. (line 199) 42569 * NOTE_INSN_EH_REGION_END: Insns. (line 199) 42570 * NOTE_INSN_FUNCTION_BEG: Insns. (line 223) 42571 * NOTE_INSN_LOOP_BEG: Insns. (line 207) 42572 * NOTE_INSN_LOOP_CONT: Insns. (line 213) 42573 * NOTE_INSN_LOOP_END: Insns. (line 207) 42574 * NOTE_INSN_LOOP_VTOP: Insns. (line 217) 42575 * NOTE_LINE_NUMBER: Insns. (line 168) 42576 * NOTE_SOURCE_FILE: Insns. (line 168) 42577 * NOTICE_UPDATE_CC: Condition Code. (line 33) 42578 * NUM_MACHINE_MODES: Machine Modes. (line 286) 42579 * NUM_MODES_FOR_MODE_SWITCHING: Mode Switching. (line 30) 42580 * Number of iterations analysis: Number of iterations. 42581 (line 6) 42582 * o in constraint: Simple Constraints. (line 23) 42583 * OBJC_GEN_METHOD_LABEL: Label Output. (line 411) 42584 * OBJC_JBLEN: Misc. (line 938) 42585 * OBJECT_FORMAT_COFF: Macros for Initialization. 42586 (line 97) 42587 * OFFSET_TYPE: Types. (line 6) 42588 * offsettable address: Simple Constraints. (line 23) 42589 * OImode: Machine Modes. (line 51) 42590 * Omega a solver for linear programming problems: Omega. (line 6) 42591 * OMP_ATOMIC: Expression trees. (line 6) 42592 * OMP_CLAUSE: Expression trees. (line 6) 42593 * OMP_CONTINUE: Expression trees. (line 6) 42594 * OMP_CRITICAL: Expression trees. (line 6) 42595 * OMP_FOR: Expression trees. (line 6) 42596 * OMP_MASTER: Expression trees. (line 6) 42597 * OMP_ORDERED: Expression trees. (line 6) 42598 * OMP_PARALLEL: Expression trees. (line 6) 42599 * OMP_RETURN: Expression trees. (line 6) 42600 * OMP_SECTION: Expression trees. (line 6) 42601 * OMP_SECTIONS: Expression trees. (line 6) 42602 * OMP_SINGLE: Expression trees. (line 6) 42603 * one_cmplM2 instruction pattern: Standard Names. (line 651) 42604 * operand access: Accessors. (line 6) 42605 * Operand Access Routines: SSA Operands. (line 119) 42606 * operand constraints: Constraints. (line 6) 42607 * Operand Iterators: SSA Operands. (line 119) 42608 * operand predicates: Predicates. (line 6) 42609 * operand substitution: Output Template. (line 6) 42610 * operands <1>: SSA Operands. (line 6) 42611 * operands: Patterns. (line 53) 42612 * Operands: Operands. (line 6) 42613 * operator predicates: Predicates. (line 6) 42614 * optc-gen.awk: Options. (line 6) 42615 * Optimization infrastructure for GIMPLE: Tree SSA. (line 6) 42616 * OPTIMIZATION_OPTIONS: Run-time Target. (line 120) 42617 * OPTIMIZE_MODE_SWITCHING: Mode Switching. (line 9) 42618 * option specification files: Options. (line 6) 42619 * OPTION_DEFAULT_SPECS: Driver. (line 88) 42620 * optional hardware or system features: Run-time Target. (line 59) 42621 * options, directory search: Including Patterns. (line 44) 42622 * order of register allocation: Allocation Order. (line 6) 42623 * ORDER_REGS_FOR_LOCAL_ALLOC: Allocation Order. (line 23) 42624 * ORDERED_EXPR: Expression trees. (line 6) 42625 * Ordering of Patterns: Pattern Ordering. (line 6) 42626 * ORIGINAL_REGNO: Special Accessors. (line 40) 42627 * other register constraints: Simple Constraints. (line 163) 42628 * OUTGOING_REG_PARM_STACK_SPACE: Stack Arguments. (line 71) 42629 * OUTGOING_REGNO: Register Basics. (line 98) 42630 * output of assembler code: File Framework. (line 6) 42631 * output statements: Output Statement. (line 6) 42632 * output templates: Output Template. (line 6) 42633 * OUTPUT_ADDR_CONST_EXTRA: Data Output. (line 39) 42634 * output_asm_insn: Output Statement. (line 53) 42635 * OUTPUT_QUOTED_STRING: File Framework. (line 76) 42636 * OVERLOAD: Functions. (line 6) 42637 * OVERRIDE_ABI_FORMAT: Register Arguments. (line 140) 42638 * OVERRIDE_OPTIONS: Run-time Target. (line 104) 42639 * OVL_CURRENT: Functions. (line 6) 42640 * OVL_NEXT: Functions. (line 6) 42641 * p in constraint: Simple Constraints. (line 154) 42642 * PAD_VARARGS_DOWN: Register Arguments. (line 221) 42643 * parallel: Side Effects. (line 204) 42644 * param_is: GTY Options. (line 114) 42645 * parameters, c++ abi: C++ ABI. (line 6) 42646 * parameters, miscellaneous: Misc. (line 6) 42647 * parameters, precompiled headers: PCH Target. (line 6) 42648 * paramN_is: GTY Options. (line 132) 42649 * parity: Arithmetic. (line 228) 42650 * parityM2 instruction pattern: Standard Names. (line 645) 42651 * PARM_BOUNDARY: Storage Layout. (line 144) 42652 * PARM_DECL: Declarations. (line 6) 42653 * PARSE_LDD_OUTPUT: Macros for Initialization. 42654 (line 121) 42655 * passes and files of the compiler: Passes. (line 6) 42656 * passing arguments: Interface. (line 36) 42657 * PATH_SEPARATOR: Filesystem. (line 31) 42658 * PATTERN: Insns. (line 247) 42659 * pattern conditions: Patterns. (line 43) 42660 * pattern names: Standard Names. (line 6) 42661 * Pattern Ordering: Pattern Ordering. (line 6) 42662 * patterns: Patterns. (line 6) 42663 * pc: Regs and Memory. (line 361) 42664 * pc and attributes: Insn Lengths. (line 20) 42665 * pc, RTL sharing: Sharing. (line 25) 42666 * PC_REGNUM: Register Basics. (line 112) 42667 * pc_rtx: Regs and Memory. (line 366) 42668 * PCC_BITFIELD_TYPE_MATTERS: Storage Layout. (line 314) 42669 * PCC_STATIC_STRUCT_RETURN: Aggregate Return. (line 64) 42670 * PDImode: Machine Modes. (line 40) 42671 * peephole optimization, RTL representation: Side Effects. (line 238) 42672 * peephole optimizer definitions: Peephole Definitions. 42673 (line 6) 42674 * per-function data: Per-Function Data. (line 6) 42675 * percent sign: Output Template. (line 6) 42676 * PHI nodes: SSA. (line 31) 42677 * phi_arg_d: GIMPLE_PHI. (line 28) 42678 * PHI_ARG_DEF: SSA. (line 71) 42679 * PHI_ARG_EDGE: SSA. (line 68) 42680 * PHI_ARG_ELT: SSA. (line 63) 42681 * PHI_NUM_ARGS: SSA. (line 59) 42682 * PHI_RESULT: SSA. (line 56) 42683 * PIC: PIC. (line 6) 42684 * PIC_OFFSET_TABLE_REG_CALL_CLOBBERED: PIC. (line 26) 42685 * PIC_OFFSET_TABLE_REGNUM: PIC. (line 16) 42686 * pipeline hazard recognizer: Processor pipeline description. 42687 (line 6) 42688 * Plugins: Plugins. (line 6) 42689 * plus: Arithmetic. (line 14) 42690 * plus and attributes: Expressions. (line 64) 42691 * plus, canonicalization of: Insn Canonicalizations. 42692 (line 27) 42693 * PLUS_EXPR: Expression trees. (line 6) 42694 * Pmode: Misc. (line 344) 42695 * pmode_register_operand: Machine-Independent Predicates. 42696 (line 35) 42697 * pointer: Types. (line 6) 42698 * POINTER_PLUS_EXPR: Expression trees. (line 6) 42699 * POINTER_SIZE: Storage Layout. (line 83) 42700 * POINTER_TYPE: Types. (line 6) 42701 * POINTERS_EXTEND_UNSIGNED: Storage Layout. (line 89) 42702 * pop_operand: Machine-Independent Predicates. 42703 (line 88) 42704 * popcount: Arithmetic. (line 224) 42705 * popcountM2 instruction pattern: Standard Names. (line 639) 42706 * portability: Portability. (line 6) 42707 * position independent code: PIC. (line 6) 42708 * post_dec: Incdec. (line 25) 42709 * post_inc: Incdec. (line 30) 42710 * post_modify: Incdec. (line 33) 42711 * POSTDECREMENT_EXPR: Expression trees. (line 6) 42712 * POSTINCREMENT_EXPR: Expression trees. (line 6) 42713 * POWI_MAX_MULTS: Misc. (line 836) 42714 * powM3 instruction pattern: Standard Names. (line 513) 42715 * pragma: Misc. (line 487) 42716 * pre_dec: Incdec. (line 8) 42717 * PRE_GCC3_DWARF_FRAME_REGISTERS: Frame Registers. (line 110) 42718 * pre_inc: Incdec. (line 22) 42719 * pre_modify: Incdec. (line 51) 42720 * PREDECREMENT_EXPR: Expression trees. (line 6) 42721 * predefined macros: Run-time Target. (line 6) 42722 * predicates: Predicates. (line 6) 42723 * predicates and machine modes: Predicates. (line 31) 42724 * predication: Conditional Execution. 42725 (line 6) 42726 * predict.def: Profile information. 42727 (line 24) 42728 * PREFERRED_DEBUGGING_TYPE: All Debuggers. (line 42) 42729 * PREFERRED_OUTPUT_RELOAD_CLASS: Register Classes. (line 231) 42730 * PREFERRED_RELOAD_CLASS: Register Classes. (line 196) 42731 * PREFERRED_STACK_BOUNDARY: Storage Layout. (line 158) 42732 * prefetch: Side Effects. (line 312) 42733 * prefetch instruction pattern: Standard Names. (line 1392) 42734 * PREINCREMENT_EXPR: Expression trees. (line 6) 42735 * presence_set: Processor pipeline description. 42736 (line 215) 42737 * preserving SSA form: SSA. (line 76) 42738 * preserving virtual SSA form: SSA. (line 186) 42739 * prev_active_insn: define_peephole. (line 60) 42740 * prev_cc0_setter: Jump Patterns. (line 64) 42741 * PREV_INSN: Insns. (line 26) 42742 * PRINT_OPERAND: Instruction Output. (line 68) 42743 * PRINT_OPERAND_ADDRESS: Instruction Output. (line 96) 42744 * PRINT_OPERAND_PUNCT_VALID_P: Instruction Output. (line 89) 42745 * processor functional units: Processor pipeline description. 42746 (line 68) 42747 * processor pipeline description: Processor pipeline description. 42748 (line 6) 42749 * product: Arithmetic. (line 92) 42750 * profile feedback: Profile information. 42751 (line 14) 42752 * profile representation: Profile information. 42753 (line 6) 42754 * PROFILE_BEFORE_PROLOGUE: Profiling. (line 35) 42755 * PROFILE_HOOK: Profiling. (line 23) 42756 * profiling, code generation: Profiling. (line 6) 42757 * program counter: Regs and Memory. (line 362) 42758 * prologue: Function Entry. (line 6) 42759 * prologue instruction pattern: Standard Names. (line 1338) 42760 * PROMOTE_FUNCTION_MODE: Storage Layout. (line 123) 42761 * PROMOTE_MODE: Storage Layout. (line 100) 42762 * pseudo registers: Regs and Memory. (line 9) 42763 * PSImode: Machine Modes. (line 32) 42764 * PTRDIFF_TYPE: Type Layout. (line 184) 42765 * PTRMEM_CST: Expression trees. (line 6) 42766 * PTRMEM_CST_CLASS: Expression trees. (line 6) 42767 * PTRMEM_CST_MEMBER: Expression trees. (line 6) 42768 * purge_dead_edges <1>: Maintaining the CFG. 42769 (line 93) 42770 * purge_dead_edges: Edges. (line 104) 42771 * push address instruction: Simple Constraints. (line 154) 42772 * PUSH_ARGS: Stack Arguments. (line 18) 42773 * PUSH_ARGS_REVERSED: Stack Arguments. (line 26) 42774 * push_operand: Machine-Independent Predicates. 42775 (line 81) 42776 * push_reload: Addressing Modes. (line 169) 42777 * PUSH_ROUNDING: Stack Arguments. (line 32) 42778 * pushM1 instruction pattern: Standard Names. (line 209) 42779 * PUT_CODE: RTL Objects. (line 47) 42780 * PUT_MODE: Machine Modes. (line 283) 42781 * PUT_REG_NOTE_KIND: Insns. (line 309) 42782 * PUT_SDB_: SDB and DWARF. (line 63) 42783 * QCmode: Machine Modes. (line 197) 42784 * QFmode: Machine Modes. (line 54) 42785 * QImode: Machine Modes. (line 25) 42786 * QImode, in insn: Insns. (line 231) 42787 * QQmode: Machine Modes. (line 103) 42788 * qualified type: Types. (line 6) 42789 * querying function unit reservations: Processor pipeline description. 42790 (line 90) 42791 * question mark: Multi-Alternative. (line 41) 42792 * quotient: Arithmetic. (line 111) 42793 * r in constraint: Simple Constraints. (line 56) 42794 * RANGE_TEST_NON_SHORT_CIRCUIT: Costs. (line 204) 42795 * RDIV_EXPR: Expression trees. (line 6) 42796 * READONLY_DATA_SECTION_ASM_OP: Sections. (line 63) 42797 * real operands: SSA Operands. (line 6) 42798 * REAL_ARITHMETIC: Floating Point. (line 66) 42799 * REAL_CST: Expression trees. (line 6) 42800 * REAL_LIBGCC_SPEC: Driver. (line 187) 42801 * REAL_NM_FILE_NAME: Macros for Initialization. 42802 (line 106) 42803 * REAL_TYPE: Types. (line 6) 42804 * REAL_VALUE_ABS: Floating Point. (line 82) 42805 * REAL_VALUE_ATOF: Floating Point. (line 50) 42806 * REAL_VALUE_FIX: Floating Point. (line 41) 42807 * REAL_VALUE_FROM_INT: Floating Point. (line 99) 42808 * REAL_VALUE_ISINF: Floating Point. (line 59) 42809 * REAL_VALUE_ISNAN: Floating Point. (line 62) 42810 * REAL_VALUE_NEGATE: Floating Point. (line 79) 42811 * REAL_VALUE_NEGATIVE: Floating Point. (line 56) 42812 * REAL_VALUE_TO_INT: Floating Point. (line 93) 42813 * REAL_VALUE_TO_TARGET_DECIMAL128: Data Output. (line 144) 42814 * REAL_VALUE_TO_TARGET_DECIMAL32: Data Output. (line 142) 42815 * REAL_VALUE_TO_TARGET_DECIMAL64: Data Output. (line 143) 42816 * REAL_VALUE_TO_TARGET_DOUBLE: Data Output. (line 140) 42817 * REAL_VALUE_TO_TARGET_LONG_DOUBLE: Data Output. (line 141) 42818 * REAL_VALUE_TO_TARGET_SINGLE: Data Output. (line 139) 42819 * REAL_VALUE_TRUNCATE: Floating Point. (line 86) 42820 * REAL_VALUE_TYPE: Floating Point. (line 26) 42821 * REAL_VALUE_UNSIGNED_FIX: Floating Point. (line 45) 42822 * REAL_VALUES_EQUAL: Floating Point. (line 32) 42823 * REAL_VALUES_LESS: Floating Point. (line 38) 42824 * REALPART_EXPR: Expression trees. (line 6) 42825 * recog_data.operand: Instruction Output. (line 39) 42826 * recognizing insns: RTL Template. (line 6) 42827 * RECORD_TYPE <1>: Classes. (line 6) 42828 * RECORD_TYPE: Types. (line 6) 42829 * redirect_edge_and_branch: Profile information. 42830 (line 71) 42831 * redirect_edge_and_branch, redirect_jump: Maintaining the CFG. 42832 (line 103) 42833 * reduc_smax_M instruction pattern: Standard Names. (line 240) 42834 * reduc_smin_M instruction pattern: Standard Names. (line 240) 42835 * reduc_splus_M instruction pattern: Standard Names. (line 252) 42836 * reduc_umax_M instruction pattern: Standard Names. (line 246) 42837 * reduc_umin_M instruction pattern: Standard Names. (line 246) 42838 * reduc_uplus_M instruction pattern: Standard Names. (line 258) 42839 * reference: Types. (line 6) 42840 * REFERENCE_TYPE: Types. (line 6) 42841 * reg: Regs and Memory. (line 9) 42842 * reg and /f: Flags. (line 112) 42843 * reg and /i: Flags. (line 107) 42844 * reg and /v: Flags. (line 116) 42845 * reg, RTL sharing: Sharing. (line 17) 42846 * REG_ALLOC_ORDER: Allocation Order. (line 9) 42847 * REG_BR_PRED: Insns. (line 491) 42848 * REG_BR_PROB: Insns. (line 485) 42849 * REG_BR_PROB_BASE, BB_FREQ_BASE, count: Profile information. 42850 (line 82) 42851 * REG_BR_PROB_BASE, EDGE_FREQUENCY: Profile information. 42852 (line 52) 42853 * REG_CC_SETTER: Insns. (line 456) 42854 * REG_CC_USER: Insns. (line 456) 42855 * reg_class_contents: Register Basics. (line 59) 42856 * REG_CLASS_CONTENTS: Register Classes. (line 86) 42857 * REG_CLASS_FROM_CONSTRAINT: Old Constraints. (line 35) 42858 * REG_CLASS_FROM_LETTER: Old Constraints. (line 27) 42859 * REG_CLASS_NAMES: Register Classes. (line 81) 42860 * REG_CROSSING_JUMP: Insns. (line 368) 42861 * REG_DEAD: Insns. (line 320) 42862 * REG_DEAD, REG_UNUSED: Liveness information. 42863 (line 32) 42864 * REG_DEP_ANTI: Insns. (line 478) 42865 * REG_DEP_OUTPUT: Insns. (line 474) 42866 * REG_DEP_TRUE: Insns. (line 471) 42867 * REG_EH_REGION, EDGE_ABNORMAL_CALL: Edges. (line 110) 42868 * REG_EQUAL: Insns. (line 384) 42869 * REG_EQUIV: Insns. (line 384) 42870 * REG_EXPR: Special Accessors. (line 46) 42871 * REG_FRAME_RELATED_EXPR: Insns. (line 497) 42872 * REG_FUNCTION_VALUE_P: Flags. (line 107) 42873 * REG_INC: Insns. (line 336) 42874 * reg_label and /v: Flags. (line 65) 42875 * REG_LABEL_OPERAND: Insns. (line 350) 42876 * REG_LABEL_TARGET: Insns. (line 359) 42877 * reg_names <1>: Instruction Output. (line 80) 42878 * reg_names: Register Basics. (line 59) 42879 * REG_NONNEG: Insns. (line 342) 42880 * REG_NOTE_KIND: Insns. (line 309) 42881 * REG_NOTES: Insns. (line 283) 42882 * REG_OFFSET: Special Accessors. (line 50) 42883 * REG_OK_STRICT: Addressing Modes. (line 67) 42884 * REG_PARM_STACK_SPACE: Stack Arguments. (line 56) 42885 * REG_PARM_STACK_SPACE, and FUNCTION_ARG: Register Arguments. 42886 (line 52) 42887 * REG_POINTER: Flags. (line 112) 42888 * REG_SETJMP: Insns. (line 378) 42889 * REG_UNUSED: Insns. (line 329) 42890 * REG_USERVAR_P: Flags. (line 116) 42891 * regclass_for_constraint: C Constraint Interface. 42892 (line 60) 42893 * register allocation order: Allocation Order. (line 6) 42894 * register class definitions: Register Classes. (line 6) 42895 * register class preference constraints: Class Preferences. (line 6) 42896 * register pairs: Values in Registers. 42897 (line 69) 42898 * Register Transfer Language (RTL): RTL. (line 6) 42899 * register usage: Registers. (line 6) 42900 * REGISTER_MOVE_COST: Costs. (line 10) 42901 * REGISTER_NAMES: Instruction Output. (line 9) 42902 * register_operand: Machine-Independent Predicates. 42903 (line 30) 42904 * REGISTER_PREFIX: Instruction Output. (line 124) 42905 * REGISTER_TARGET_PRAGMAS: Misc. (line 382) 42906 * registers arguments: Register Arguments. (line 6) 42907 * registers in constraints: Simple Constraints. (line 56) 42908 * REGMODE_NATURAL_SIZE: Values in Registers. 42909 (line 50) 42910 * REGNO_MODE_CODE_OK_FOR_BASE_P: Register Classes. (line 170) 42911 * REGNO_MODE_OK_FOR_BASE_P: Register Classes. (line 146) 42912 * REGNO_MODE_OK_FOR_REG_BASE_P: Register Classes. (line 157) 42913 * REGNO_OK_FOR_BASE_P: Register Classes. (line 140) 42914 * REGNO_OK_FOR_INDEX_P: Register Classes. (line 181) 42915 * REGNO_REG_CLASS: Register Classes. (line 101) 42916 * regs_ever_live: Function Entry. (line 21) 42917 * regular expressions: Processor pipeline description. 42918 (line 6) 42919 * relative costs: Costs. (line 6) 42920 * RELATIVE_PREFIX_NOT_LINKDIR: Driver. (line 325) 42921 * reload_completed: Standard Names. (line 1040) 42922 * reload_in instruction pattern: Standard Names. (line 99) 42923 * reload_in_progress: Standard Names. (line 57) 42924 * reload_out instruction pattern: Standard Names. (line 99) 42925 * reloading: RTL passes. (line 191) 42926 * remainder: Arithmetic. (line 131) 42927 * remainderM3 instruction pattern: Standard Names. (line 472) 42928 * reorder: GTY Options. (line 210) 42929 * representation of RTL: RTL. (line 6) 42930 * reservation delays: Processor pipeline description. 42931 (line 6) 42932 * rest_of_decl_compilation: Parsing pass. (line 52) 42933 * rest_of_type_compilation: Parsing pass. (line 52) 42934 * restore_stack_block instruction pattern: Standard Names. (line 1174) 42935 * restore_stack_function instruction pattern: Standard Names. 42936 (line 1174) 42937 * restore_stack_nonlocal instruction pattern: Standard Names. 42938 (line 1174) 42939 * RESULT_DECL: Declarations. (line 6) 42940 * return: Side Effects. (line 72) 42941 * return instruction pattern: Standard Names. (line 1027) 42942 * return values in registers: Scalar Return. (line 6) 42943 * RETURN_ADDR_IN_PREVIOUS_FRAME: Frame Layout. (line 135) 42944 * RETURN_ADDR_OFFSET: Exception Handling. (line 60) 42945 * RETURN_ADDR_RTX: Frame Layout. (line 124) 42946 * RETURN_ADDRESS_POINTER_REGNUM: Frame Registers. (line 51) 42947 * RETURN_EXPR: Function Bodies. (line 6) 42948 * RETURN_POPS_ARGS: Stack Arguments. (line 90) 42949 * RETURN_STMT: Function Bodies. (line 6) 42950 * return_val: Flags. (line 294) 42951 * return_val, in call_insn: Flags. (line 24) 42952 * return_val, in mem: Flags. (line 85) 42953 * return_val, in reg: Flags. (line 107) 42954 * return_val, in symbol_ref: Flags. (line 220) 42955 * returning aggregate values: Aggregate Return. (line 6) 42956 * returning structures and unions: Interface. (line 10) 42957 * reverse probability: Profile information. 42958 (line 66) 42959 * REVERSE_CONDEXEC_PREDICATES_P: Condition Code. (line 129) 42960 * REVERSE_CONDITION: Condition Code. (line 116) 42961 * REVERSIBLE_CC_MODE: Condition Code. (line 102) 42962 * right rotate: Arithmetic. (line 190) 42963 * right shift: Arithmetic. (line 185) 42964 * rintM2 instruction pattern: Standard Names. (line 572) 42965 * RISC: Processor pipeline description. 42966 (line 6) 42967 * roots, marking: GGC Roots. (line 6) 42968 * rotate: Arithmetic. (line 190) 42969 * rotatert: Arithmetic. (line 190) 42970 * rotlM3 instruction pattern: Standard Names. (line 441) 42971 * rotrM3 instruction pattern: Standard Names. (line 441) 42972 * ROUND_DIV_EXPR: Expression trees. (line 6) 42973 * ROUND_MOD_EXPR: Expression trees. (line 6) 42974 * ROUND_TOWARDS_ZERO: Storage Layout. (line 460) 42975 * ROUND_TYPE_ALIGN: Storage Layout. (line 411) 42976 * roundM2 instruction pattern: Standard Names. (line 548) 42977 * RSHIFT_EXPR: Expression trees. (line 6) 42978 * RTL addition: Arithmetic. (line 14) 42979 * RTL addition with signed saturation: Arithmetic. (line 14) 42980 * RTL addition with unsigned saturation: Arithmetic. (line 14) 42981 * RTL classes: RTL Classes. (line 6) 42982 * RTL comparison: Arithmetic. (line 43) 42983 * RTL comparison operations: Comparisons. (line 6) 42984 * RTL constant expression types: Constants. (line 6) 42985 * RTL constants: Constants. (line 6) 42986 * RTL declarations: RTL Declarations. (line 6) 42987 * RTL difference: Arithmetic. (line 36) 42988 * RTL expression: RTL Objects. (line 6) 42989 * RTL expressions for arithmetic: Arithmetic. (line 6) 42990 * RTL format: RTL Classes. (line 71) 42991 * RTL format characters: RTL Classes. (line 76) 42992 * RTL function-call insns: Calls. (line 6) 42993 * RTL insn template: RTL Template. (line 6) 42994 * RTL integers: RTL Objects. (line 6) 42995 * RTL memory expressions: Regs and Memory. (line 6) 42996 * RTL object types: RTL Objects. (line 6) 42997 * RTL postdecrement: Incdec. (line 6) 42998 * RTL postincrement: Incdec. (line 6) 42999 * RTL predecrement: Incdec. (line 6) 43000 * RTL preincrement: Incdec. (line 6) 43001 * RTL register expressions: Regs and Memory. (line 6) 43002 * RTL representation: RTL. (line 6) 43003 * RTL side effect expressions: Side Effects. (line 6) 43004 * RTL strings: RTL Objects. (line 6) 43005 * RTL structure sharing assumptions: Sharing. (line 6) 43006 * RTL subtraction: Arithmetic. (line 36) 43007 * RTL subtraction with signed saturation: Arithmetic. (line 36) 43008 * RTL subtraction with unsigned saturation: Arithmetic. (line 36) 43009 * RTL sum: Arithmetic. (line 14) 43010 * RTL vectors: RTL Objects. (line 6) 43011 * RTL_CONST_CALL_P: Flags. (line 19) 43012 * RTL_CONST_OR_PURE_CALL_P: Flags. (line 29) 43013 * RTL_LOOPING_CONST_OR_PURE_CALL_P: Flags. (line 33) 43014 * RTL_PURE_CALL_P: Flags. (line 24) 43015 * RTX (See RTL): RTL Objects. (line 6) 43016 * RTX codes, classes of: RTL Classes. (line 6) 43017 * RTX_FRAME_RELATED_P: Flags. (line 125) 43018 * run-time conventions: Interface. (line 6) 43019 * run-time target specification: Run-time Target. (line 6) 43020 * s in constraint: Simple Constraints. (line 92) 43021 * same_type_p: Types. (line 148) 43022 * SAmode: Machine Modes. (line 148) 43023 * sat_fract: Conversions. (line 90) 43024 * satfractMN2 instruction pattern: Standard Names. (line 843) 43025 * satfractunsMN2 instruction pattern: Standard Names. (line 856) 43026 * satisfies_constraint_: C Constraint Interface. 43027 (line 47) 43028 * SAVE_EXPR: Expression trees. (line 6) 43029 * save_stack_block instruction pattern: Standard Names. (line 1174) 43030 * save_stack_function instruction pattern: Standard Names. (line 1174) 43031 * save_stack_nonlocal instruction pattern: Standard Names. (line 1174) 43032 * SBSS_SECTION_ASM_OP: Sections. (line 77) 43033 * Scalar evolutions: Scalar evolutions. (line 6) 43034 * scalars, returned as values: Scalar Return. (line 6) 43035 * SCHED_GROUP_P: Flags. (line 166) 43036 * SCmode: Machine Modes. (line 197) 43037 * sCOND instruction pattern: Standard Names. (line 911) 43038 * scratch: Regs and Memory. (line 298) 43039 * scratch operands: Regs and Memory. (line 298) 43040 * scratch, RTL sharing: Sharing. (line 35) 43041 * scratch_operand: Machine-Independent Predicates. 43042 (line 50) 43043 * SDATA_SECTION_ASM_OP: Sections. (line 58) 43044 * SDB_ALLOW_FORWARD_REFERENCES: SDB and DWARF. (line 81) 43045 * SDB_ALLOW_UNKNOWN_REFERENCES: SDB and DWARF. (line 76) 43046 * SDB_DEBUGGING_INFO: SDB and DWARF. (line 9) 43047 * SDB_DELIM: SDB and DWARF. (line 69) 43048 * SDB_OUTPUT_SOURCE_LINE: SDB and DWARF. (line 86) 43049 * SDmode: Machine Modes. (line 85) 43050 * sdot_prodM instruction pattern: Standard Names. (line 264) 43051 * search options: Including Patterns. (line 44) 43052 * SECONDARY_INPUT_RELOAD_CLASS: Register Classes. (line 335) 43053 * SECONDARY_MEMORY_NEEDED: Register Classes. (line 391) 43054 * SECONDARY_MEMORY_NEEDED_MODE: Register Classes. (line 410) 43055 * SECONDARY_MEMORY_NEEDED_RTX: Register Classes. (line 401) 43056 * SECONDARY_OUTPUT_RELOAD_CLASS: Register Classes. (line 336) 43057 * SECONDARY_RELOAD_CLASS: Register Classes. (line 334) 43058 * SELECT_CC_MODE: Condition Code. (line 68) 43059 * sequence: Side Effects. (line 254) 43060 * Sequence iterators: Sequence iterators. (line 6) 43061 * set: Side Effects. (line 15) 43062 * set and /f: Flags. (line 125) 43063 * SET_ASM_OP: Label Output. (line 378) 43064 * set_attr: Tagging Insns. (line 31) 43065 * set_attr_alternative: Tagging Insns. (line 49) 43066 * set_bb_seq: GIMPLE sequences. (line 76) 43067 * SET_BY_PIECES_P: Costs. (line 145) 43068 * SET_DEST: Side Effects. (line 69) 43069 * SET_IS_RETURN_P: Flags. (line 175) 43070 * SET_LABEL_KIND: Insns. (line 140) 43071 * set_optab_libfunc: Library Calls. (line 15) 43072 * SET_RATIO: Costs. (line 136) 43073 * SET_SRC: Side Effects. (line 69) 43074 * SET_TYPE_STRUCTURAL_EQUALITY: Types. (line 143) 43075 * setmemM instruction pattern: Standard Names. (line 715) 43076 * SETUP_FRAME_ADDRESSES: Frame Layout. (line 102) 43077 * SF_SIZE: Type Layout. (line 129) 43078 * SFmode: Machine Modes. (line 66) 43079 * sharing of RTL components: Sharing. (line 6) 43080 * shift: Arithmetic. (line 168) 43081 * SHIFT_COUNT_TRUNCATED: Misc. (line 127) 43082 * SHLIB_SUFFIX: Macros for Initialization. 43083 (line 129) 43084 * SHORT_ACCUM_TYPE_SIZE: Type Layout. (line 83) 43085 * SHORT_FRACT_TYPE_SIZE: Type Layout. (line 63) 43086 * SHORT_IMMEDIATES_SIGN_EXTEND: Misc. (line 96) 43087 * SHORT_TYPE_SIZE: Type Layout. (line 16) 43088 * sibcall_epilogue instruction pattern: Standard Names. (line 1364) 43089 * sibling call: Edges. (line 122) 43090 * SIBLING_CALL_P: Flags. (line 179) 43091 * sign_extend: Conversions. (line 23) 43092 * sign_extract: Bit-Fields. (line 8) 43093 * sign_extract, canonicalization of: Insn Canonicalizations. 43094 (line 96) 43095 * signed division: Arithmetic. (line 111) 43096 * signed division with signed saturation: Arithmetic. (line 111) 43097 * signed maximum: Arithmetic. (line 136) 43098 * signed minimum: Arithmetic. (line 136) 43099 * SImode: Machine Modes. (line 37) 43100 * simple constraints: Simple Constraints. (line 6) 43101 * sincos math function, implicit usage: Library Calls. (line 84) 43102 * sinM2 instruction pattern: Standard Names. (line 489) 43103 * SIZE_ASM_OP: Label Output. (line 23) 43104 * SIZE_TYPE: Type Layout. (line 168) 43105 * skip: GTY Options. (line 77) 43106 * SLOW_BYTE_ACCESS: Costs. (line 66) 43107 * SLOW_UNALIGNED_ACCESS: Costs. (line 81) 43108 * SMALL_REGISTER_CLASSES: Register Classes. (line 433) 43109 * smax: Arithmetic. (line 136) 43110 * smin: Arithmetic. (line 136) 43111 * sms, swing, software pipelining: RTL passes. (line 140) 43112 * smulM3_highpart instruction pattern: Standard Names. (line 356) 43113 * soft float library: Soft float library routines. 43114 (line 6) 43115 * special: GTY Options. (line 230) 43116 * special predicates: Predicates. (line 31) 43117 * SPECS: Target Fragment. (line 108) 43118 * speed of instructions: Costs. (line 6) 43119 * split_block: Maintaining the CFG. 43120 (line 110) 43121 * splitting instructions: Insn Splitting. (line 6) 43122 * SQmode: Machine Modes. (line 111) 43123 * sqrt: Arithmetic. (line 198) 43124 * sqrtM2 instruction pattern: Standard Names. (line 455) 43125 * square root: Arithmetic. (line 198) 43126 * ss_ashift: Arithmetic. (line 168) 43127 * ss_div: Arithmetic. (line 111) 43128 * ss_minus: Arithmetic. (line 36) 43129 * ss_mult: Arithmetic. (line 92) 43130 * ss_neg: Arithmetic. (line 81) 43131 * ss_plus: Arithmetic. (line 14) 43132 * ss_truncate: Conversions. (line 43) 43133 * SSA: SSA. (line 6) 43134 * SSA_NAME_DEF_STMT: SSA. (line 221) 43135 * SSA_NAME_VERSION: SSA. (line 226) 43136 * ssaddM3 instruction pattern: Standard Names. (line 222) 43137 * ssashlM3 instruction pattern: Standard Names. (line 431) 43138 * ssdivM3 instruction pattern: Standard Names. (line 222) 43139 * ssmaddMN4 instruction pattern: Standard Names. (line 379) 43140 * ssmsubMN4 instruction pattern: Standard Names. (line 403) 43141 * ssmulM3 instruction pattern: Standard Names. (line 222) 43142 * ssnegM2 instruction pattern: Standard Names. (line 449) 43143 * sssubM3 instruction pattern: Standard Names. (line 222) 43144 * ssum_widenM3 instruction pattern: Standard Names. (line 274) 43145 * stack arguments: Stack Arguments. (line 6) 43146 * stack frame layout: Frame Layout. (line 6) 43147 * stack smashing protection: Stack Smashing Protection. 43148 (line 6) 43149 * STACK_ALIGNMENT_NEEDED: Frame Layout. (line 48) 43150 * STACK_BOUNDARY: Storage Layout. (line 150) 43151 * STACK_CHECK_BUILTIN: Stack Checking. (line 32) 43152 * STACK_CHECK_FIXED_FRAME_SIZE: Stack Checking. (line 77) 43153 * STACK_CHECK_MAX_FRAME_SIZE: Stack Checking. (line 68) 43154 * STACK_CHECK_MAX_VAR_SIZE: Stack Checking. (line 84) 43155 * STACK_CHECK_PROBE_INTERVAL: Stack Checking. (line 46) 43156 * STACK_CHECK_PROBE_LOAD: Stack Checking. (line 53) 43157 * STACK_CHECK_PROTECT: Stack Checking. (line 59) 43158 * STACK_CHECK_STATIC_BUILTIN: Stack Checking. (line 39) 43159 * STACK_DYNAMIC_OFFSET: Frame Layout. (line 75) 43160 * STACK_DYNAMIC_OFFSET and virtual registers: Regs and Memory. 43161 (line 83) 43162 * STACK_GROWS_DOWNWARD: Frame Layout. (line 9) 43163 * STACK_PARMS_IN_REG_PARM_AREA: Stack Arguments. (line 81) 43164 * STACK_POINTER_OFFSET: Frame Layout. (line 58) 43165 * STACK_POINTER_OFFSET and virtual registers: Regs and Memory. 43166 (line 93) 43167 * STACK_POINTER_REGNUM: Frame Registers. (line 9) 43168 * STACK_POINTER_REGNUM and virtual registers: Regs and Memory. 43169 (line 83) 43170 * stack_pointer_rtx: Frame Registers. (line 85) 43171 * stack_protect_set instruction pattern: Standard Names. (line 1536) 43172 * stack_protect_test instruction pattern: Standard Names. (line 1546) 43173 * STACK_PUSH_CODE: Frame Layout. (line 17) 43174 * STACK_REGS: Stack Registers. (line 20) 43175 * STACK_SAVEAREA_MODE: Storage Layout. (line 427) 43176 * STACK_SIZE_MODE: Storage Layout. (line 439) 43177 * STACK_SLOT_ALIGNMENT: Storage Layout. (line 265) 43178 * standard pattern names: Standard Names. (line 6) 43179 * STANDARD_INCLUDE_COMPONENT: Driver. (line 425) 43180 * STANDARD_INCLUDE_DIR: Driver. (line 417) 43181 * STANDARD_STARTFILE_PREFIX: Driver. (line 337) 43182 * STANDARD_STARTFILE_PREFIX_1: Driver. (line 344) 43183 * STANDARD_STARTFILE_PREFIX_2: Driver. (line 351) 43184 * STARTFILE_SPEC: Driver. (line 210) 43185 * STARTING_FRAME_OFFSET: Frame Layout. (line 39) 43186 * STARTING_FRAME_OFFSET and virtual registers: Regs and Memory. 43187 (line 74) 43188 * Statement and operand traversals: Statement and operand traversals. 43189 (line 6) 43190 * Statement Sequences: Statement Sequences. 43191 (line 6) 43192 * Statements: Statements. (line 6) 43193 * statements: Function Bodies. (line 6) 43194 * Static profile estimation: Profile information. 43195 (line 24) 43196 * static single assignment: SSA. (line 6) 43197 * STATIC_CHAIN: Frame Registers. (line 77) 43198 * STATIC_CHAIN_INCOMING: Frame Registers. (line 78) 43199 * STATIC_CHAIN_INCOMING_REGNUM: Frame Registers. (line 64) 43200 * STATIC_CHAIN_REGNUM: Frame Registers. (line 63) 43201 * stdarg.h and register arguments: Register Arguments. (line 47) 43202 * STDC_0_IN_SYSTEM_HEADERS: Misc. (line 365) 43203 * STMT_EXPR: Expression trees. (line 6) 43204 * STMT_IS_FULL_EXPR_P: Function Bodies. (line 22) 43205 * storage layout: Storage Layout. (line 6) 43206 * STORE_BY_PIECES_P: Costs. (line 152) 43207 * STORE_FLAG_VALUE: Misc. (line 216) 43208 * store_multiple instruction pattern: Standard Names. (line 160) 43209 * strcpy: Storage Layout. (line 235) 43210 * STRICT_ALIGNMENT: Storage Layout. (line 309) 43211 * strict_low_part: RTL Declarations. (line 9) 43212 * strict_memory_address_p: Addressing Modes. (line 179) 43213 * STRING_CST: Expression trees. (line 6) 43214 * STRING_POOL_ADDRESS_P: Flags. (line 183) 43215 * strlenM instruction pattern: Standard Names. (line 778) 43216 * structure value address: Aggregate Return. (line 6) 43217 * STRUCTURE_SIZE_BOUNDARY: Storage Layout. (line 301) 43218 * structures, returning: Interface. (line 10) 43219 * subM3 instruction pattern: Standard Names. (line 222) 43220 * SUBOBJECT: Function Bodies. (line 6) 43221 * SUBOBJECT_CLEANUP: Function Bodies. (line 6) 43222 * subreg: Regs and Memory. (line 97) 43223 * subreg and /s: Flags. (line 205) 43224 * subreg and /u: Flags. (line 198) 43225 * subreg and /u and /v: Flags. (line 188) 43226 * subreg, in strict_low_part: RTL Declarations. (line 9) 43227 * SUBREG_BYTE: Regs and Memory. (line 289) 43228 * SUBREG_PROMOTED_UNSIGNED_P: Flags. (line 188) 43229 * SUBREG_PROMOTED_UNSIGNED_SET: Flags. (line 198) 43230 * SUBREG_PROMOTED_VAR_P: Flags. (line 205) 43231 * SUBREG_REG: Regs and Memory. (line 289) 43232 * SUCCESS_EXIT_CODE: Host Misc. (line 12) 43233 * SUPPORTS_INIT_PRIORITY: Macros for Initialization. 43234 (line 58) 43235 * SUPPORTS_ONE_ONLY: Label Output. (line 227) 43236 * SUPPORTS_WEAK: Label Output. (line 208) 43237 * SWITCH_BODY: Function Bodies. (line 6) 43238 * SWITCH_COND: Function Bodies. (line 6) 43239 * SWITCH_CURTAILS_COMPILATION: Driver. (line 33) 43240 * SWITCH_STMT: Function Bodies. (line 6) 43241 * SWITCH_TAKES_ARG: Driver. (line 9) 43242 * SWITCHES_NEED_SPACES: Driver. (line 47) 43243 * SYMBOL_FLAG_ANCHOR: Special Accessors. (line 106) 43244 * SYMBOL_FLAG_EXTERNAL: Special Accessors. (line 88) 43245 * SYMBOL_FLAG_FUNCTION: Special Accessors. (line 81) 43246 * SYMBOL_FLAG_HAS_BLOCK_INFO: Special Accessors. (line 102) 43247 * SYMBOL_FLAG_LOCAL: Special Accessors. (line 84) 43248 * SYMBOL_FLAG_SMALL: Special Accessors. (line 93) 43249 * SYMBOL_FLAG_TLS_SHIFT: Special Accessors. (line 97) 43250 * symbol_ref: Constants. (line 76) 43251 * symbol_ref and /f: Flags. (line 183) 43252 * symbol_ref and /i: Flags. (line 220) 43253 * symbol_ref and /u: Flags. (line 10) 43254 * symbol_ref and /v: Flags. (line 224) 43255 * symbol_ref, RTL sharing: Sharing. (line 20) 43256 * SYMBOL_REF_ANCHOR_P: Special Accessors. (line 106) 43257 * SYMBOL_REF_BLOCK: Special Accessors. (line 119) 43258 * SYMBOL_REF_BLOCK_OFFSET: Special Accessors. (line 124) 43259 * SYMBOL_REF_CONSTANT: Special Accessors. (line 67) 43260 * SYMBOL_REF_DATA: Special Accessors. (line 71) 43261 * SYMBOL_REF_DECL: Special Accessors. (line 55) 43262 * SYMBOL_REF_EXTERNAL_P: Special Accessors. (line 88) 43263 * SYMBOL_REF_FLAG: Flags. (line 224) 43264 * SYMBOL_REF_FLAG, in TARGET_ENCODE_SECTION_INFO: Sections. (line 259) 43265 * SYMBOL_REF_FLAGS: Special Accessors. (line 75) 43266 * SYMBOL_REF_FUNCTION_P: Special Accessors. (line 81) 43267 * SYMBOL_REF_HAS_BLOCK_INFO_P: Special Accessors. (line 102) 43268 * SYMBOL_REF_LOCAL_P: Special Accessors. (line 84) 43269 * SYMBOL_REF_SMALL_P: Special Accessors. (line 93) 43270 * SYMBOL_REF_TLS_MODEL: Special Accessors. (line 97) 43271 * SYMBOL_REF_USED: Flags. (line 215) 43272 * SYMBOL_REF_WEAK: Flags. (line 220) 43273 * symbolic label: Sharing. (line 20) 43274 * sync_addMODE instruction pattern: Standard Names. (line 1450) 43275 * sync_andMODE instruction pattern: Standard Names. (line 1450) 43276 * sync_compare_and_swap_ccMODE instruction pattern: Standard Names. 43277 (line 1437) 43278 * sync_compare_and_swapMODE instruction pattern: Standard Names. 43279 (line 1419) 43280 * sync_iorMODE instruction pattern: Standard Names. (line 1450) 43281 * sync_lock_releaseMODE instruction pattern: Standard Names. (line 1517) 43282 * sync_lock_test_and_setMODE instruction pattern: Standard Names. 43283 (line 1491) 43284 * sync_nandMODE instruction pattern: Standard Names. (line 1450) 43285 * sync_new_addMODE instruction pattern: Standard Names. (line 1484) 43286 * sync_new_andMODE instruction pattern: Standard Names. (line 1484) 43287 * sync_new_iorMODE instruction pattern: Standard Names. (line 1484) 43288 * sync_new_nandMODE instruction pattern: Standard Names. (line 1484) 43289 * sync_new_subMODE instruction pattern: Standard Names. (line 1484) 43290 * sync_new_xorMODE instruction pattern: Standard Names. (line 1484) 43291 * sync_old_addMODE instruction pattern: Standard Names. (line 1467) 43292 * sync_old_andMODE instruction pattern: Standard Names. (line 1467) 43293 * sync_old_iorMODE instruction pattern: Standard Names. (line 1467) 43294 * sync_old_nandMODE instruction pattern: Standard Names. (line 1467) 43295 * sync_old_subMODE instruction pattern: Standard Names. (line 1467) 43296 * sync_old_xorMODE instruction pattern: Standard Names. (line 1467) 43297 * sync_subMODE instruction pattern: Standard Names. (line 1450) 43298 * sync_xorMODE instruction pattern: Standard Names. (line 1450) 43299 * SYSROOT_HEADERS_SUFFIX_SPEC: Driver. (line 239) 43300 * SYSROOT_SUFFIX_SPEC: Driver. (line 234) 43301 * SYSTEM_INCLUDE_DIR: Driver. (line 408) 43302 * t-TARGET: Target Fragment. (line 6) 43303 * table jump: Basic Blocks. (line 57) 43304 * tablejump instruction pattern: Standard Names. (line 1102) 43305 * tag: GTY Options. (line 82) 43306 * tagging insns: Tagging Insns. (line 6) 43307 * tail calls: Tail Calls. (line 6) 43308 * TAmode: Machine Modes. (line 156) 43309 * target attributes: Target Attributes. (line 6) 43310 * target description macros: Target Macros. (line 6) 43311 * target functions: Target Structure. (line 6) 43312 * target hooks: Target Structure. (line 6) 43313 * target makefile fragment: Target Fragment. (line 6) 43314 * target specifications: Run-time Target. (line 6) 43315 * TARGET_ADDRESS_COST: Costs. (line 236) 43316 * TARGET_ALIGN_ANON_BITFIELD: Storage Layout. (line 386) 43317 * TARGET_ALLOCATE_INITIAL_VALUE: Misc. (line 720) 43318 * TARGET_ALLOCATE_STACK_SLOTS_FOR_ARGS: Misc. (line 959) 43319 * TARGET_ARG_PARTIAL_BYTES: Register Arguments. (line 83) 43320 * TARGET_ARM_EABI_UNWINDER: Exception Region Output. 43321 (line 113) 43322 * TARGET_ASM_ALIGNED_DI_OP: Data Output. (line 10) 43323 * TARGET_ASM_ALIGNED_HI_OP: Data Output. (line 8) 43324 * TARGET_ASM_ALIGNED_SI_OP: Data Output. (line 9) 43325 * TARGET_ASM_ALIGNED_TI_OP: Data Output. (line 11) 43326 * TARGET_ASM_ASSEMBLE_VISIBILITY: Label Output. (line 239) 43327 * TARGET_ASM_BYTE_OP: Data Output. (line 7) 43328 * TARGET_ASM_CAN_OUTPUT_MI_THUNK: Function Entry. (line 237) 43329 * TARGET_ASM_CLOSE_PAREN: Data Output. (line 130) 43330 * TARGET_ASM_CONSTRUCTOR: Macros for Initialization. 43331 (line 69) 43332 * TARGET_ASM_DESTRUCTOR: Macros for Initialization. 43333 (line 83) 43334 * TARGET_ASM_EMIT_EXCEPT_TABLE_LABEL: Dispatch Tables. (line 74) 43335 * TARGET_ASM_EMIT_UNWIND_LABEL: Dispatch Tables. (line 63) 43336 * TARGET_ASM_EXTERNAL_LIBCALL: Label Output. (line 274) 43337 * TARGET_ASM_FILE_END: File Framework. (line 37) 43338 * TARGET_ASM_FILE_START: File Framework. (line 9) 43339 * TARGET_ASM_FILE_START_APP_OFF: File Framework. (line 17) 43340 * TARGET_ASM_FILE_START_FILE_DIRECTIVE: File Framework. (line 31) 43341 * TARGET_ASM_FUNCTION_BEGIN_EPILOGUE: Function Entry. (line 61) 43342 * TARGET_ASM_FUNCTION_END_PROLOGUE: Function Entry. (line 55) 43343 * TARGET_ASM_FUNCTION_EPILOGUE: Function Entry. (line 68) 43344 * TARGET_ASM_FUNCTION_EPILOGUE and trampolines: Trampolines. (line 70) 43345 * TARGET_ASM_FUNCTION_PROLOGUE: Function Entry. (line 11) 43346 * TARGET_ASM_FUNCTION_PROLOGUE and trampolines: Trampolines. (line 70) 43347 * TARGET_ASM_FUNCTION_RODATA_SECTION: Sections. (line 206) 43348 * TARGET_ASM_GLOBALIZE_DECL_NAME: Label Output. (line 174) 43349 * TARGET_ASM_GLOBALIZE_LABEL: Label Output. (line 165) 43350 * TARGET_ASM_INIT_SECTIONS: Sections. (line 151) 43351 * TARGET_ASM_INTEGER: Data Output. (line 27) 43352 * TARGET_ASM_INTERNAL_LABEL: Label Output. (line 309) 43353 * TARGET_ASM_MARK_DECL_PRESERVED: Label Output. (line 280) 43354 * TARGET_ASM_NAMED_SECTION: File Framework. (line 89) 43355 * TARGET_ASM_OPEN_PAREN: Data Output. (line 129) 43356 * TARGET_ASM_OUTPUT_ANCHOR: Anchored Addresses. (line 44) 43357 * TARGET_ASM_OUTPUT_DWARF_DTPREL: SDB and DWARF. (line 58) 43358 * TARGET_ASM_OUTPUT_MI_THUNK: Function Entry. (line 195) 43359 * TARGET_ASM_RECORD_GCC_SWITCHES: File Framework. (line 122) 43360 * TARGET_ASM_RECORD_GCC_SWITCHES_SECTION: File Framework. (line 166) 43361 * TARGET_ASM_SELECT_RTX_SECTION: Sections. (line 214) 43362 * TARGET_ASM_SELECT_SECTION: Sections. (line 172) 43363 * TARGET_ASM_TTYPE: Exception Region Output. 43364 (line 107) 43365 * TARGET_ASM_UNALIGNED_DI_OP: Data Output. (line 14) 43366 * TARGET_ASM_UNALIGNED_HI_OP: Data Output. (line 12) 43367 * TARGET_ASM_UNALIGNED_SI_OP: Data Output. (line 13) 43368 * TARGET_ASM_UNALIGNED_TI_OP: Data Output. (line 15) 43369 * TARGET_ASM_UNIQUE_SECTION: Sections. (line 193) 43370 * TARGET_ATTRIBUTE_TABLE: Target Attributes. (line 11) 43371 * TARGET_BINDS_LOCAL_P: Sections. (line 284) 43372 * TARGET_BRANCH_TARGET_REGISTER_CALLEE_SAVED: Misc. (line 816) 43373 * TARGET_BRANCH_TARGET_REGISTER_CLASS: Misc. (line 808) 43374 * TARGET_BUILD_BUILTIN_VA_LIST: Register Arguments. (line 264) 43375 * TARGET_BUILTIN_RECIPROCAL: Addressing Modes. (line 240) 43376 * TARGET_BUILTIN_SETJMP_FRAME_VALUE: Frame Layout. (line 109) 43377 * TARGET_C99_FUNCTIONS: Library Calls. (line 77) 43378 * TARGET_CALLEE_COPIES: Register Arguments. (line 115) 43379 * TARGET_CAN_INLINE_P: Target Attributes. (line 126) 43380 * TARGET_CANNOT_FORCE_CONST_MEM: Addressing Modes. (line 221) 43381 * TARGET_CANNOT_MODIFY_JUMPS_P: Misc. (line 795) 43382 * TARGET_CANONICAL_VA_LIST_TYPE: Register Arguments. (line 273) 43383 * TARGET_COMMUTATIVE_P: Misc. (line 713) 43384 * TARGET_COMP_TYPE_ATTRIBUTES: Target Attributes. (line 19) 43385 * TARGET_CPU_CPP_BUILTINS: Run-time Target. (line 9) 43386 * TARGET_CXX_ADJUST_CLASS_AT_DEFINITION: C++ ABI. (line 87) 43387 * TARGET_CXX_CDTOR_RETURNS_THIS: C++ ABI. (line 38) 43388 * TARGET_CXX_CLASS_DATA_ALWAYS_COMDAT: C++ ABI. (line 62) 43389 * TARGET_CXX_COOKIE_HAS_SIZE: C++ ABI. (line 25) 43390 * TARGET_CXX_DETERMINE_CLASS_DATA_VISIBILITY: C++ ABI. (line 54) 43391 * TARGET_CXX_GET_COOKIE_SIZE: C++ ABI. (line 18) 43392 * TARGET_CXX_GUARD_MASK_BIT: C++ ABI. (line 12) 43393 * TARGET_CXX_GUARD_TYPE: C++ ABI. (line 7) 43394 * TARGET_CXX_IMPORT_EXPORT_CLASS: C++ ABI. (line 30) 43395 * TARGET_CXX_KEY_METHOD_MAY_BE_INLINE: C++ ABI. (line 43) 43396 * TARGET_CXX_LIBRARY_RTTI_COMDAT: C++ ABI. (line 69) 43397 * TARGET_CXX_USE_AEABI_ATEXIT: C++ ABI. (line 74) 43398 * TARGET_CXX_USE_ATEXIT_FOR_CXA_ATEXIT: C++ ABI. (line 80) 43399 * TARGET_DECIMAL_FLOAT_SUPPORTED_P: Storage Layout. (line 513) 43400 * TARGET_DECLSPEC: Target Attributes. (line 64) 43401 * TARGET_DEFAULT_PACK_STRUCT: Misc. (line 482) 43402 * TARGET_DEFAULT_SHORT_ENUMS: Type Layout. (line 160) 43403 * TARGET_DEFERRED_OUTPUT_DEFS: Label Output. (line 393) 43404 * TARGET_DELEGITIMIZE_ADDRESS: Addressing Modes. (line 212) 43405 * TARGET_DLLIMPORT_DECL_ATTRIBUTES: Target Attributes. (line 47) 43406 * TARGET_DWARF_CALLING_CONVENTION: SDB and DWARF. (line 18) 43407 * TARGET_DWARF_HANDLE_FRAME_UNSPEC: Frame Layout. (line 172) 43408 * TARGET_DWARF_REGISTER_SPAN: Exception Region Output. 43409 (line 90) 43410 * TARGET_EDOM: Library Calls. (line 59) 43411 * TARGET_EMUTLS_DEBUG_FORM_TLS_ADDRESS: Emulated TLS. (line 68) 43412 * TARGET_EMUTLS_GET_ADDRESS: Emulated TLS. (line 19) 43413 * TARGET_EMUTLS_REGISTER_COMMON: Emulated TLS. (line 24) 43414 * TARGET_EMUTLS_TMPL_PREFIX: Emulated TLS. (line 45) 43415 * TARGET_EMUTLS_TMPL_SECTION: Emulated TLS. (line 36) 43416 * TARGET_EMUTLS_VAR_ALIGN_FIXED: Emulated TLS. (line 63) 43417 * TARGET_EMUTLS_VAR_FIELDS: Emulated TLS. (line 49) 43418 * TARGET_EMUTLS_VAR_INIT: Emulated TLS. (line 57) 43419 * TARGET_EMUTLS_VAR_PREFIX: Emulated TLS. (line 41) 43420 * TARGET_EMUTLS_VAR_SECTION: Emulated TLS. (line 31) 43421 * TARGET_ENCODE_SECTION_INFO: Sections. (line 235) 43422 * TARGET_ENCODE_SECTION_INFO and address validation: Addressing Modes. 43423 (line 91) 43424 * TARGET_ENCODE_SECTION_INFO usage: Instruction Output. (line 100) 43425 * TARGET_ENUM_VA_LIST: Scalar Return. (line 84) 43426 * TARGET_EXECUTABLE_SUFFIX: Misc. (line 769) 43427 * TARGET_EXPAND_BUILTIN: Misc. (line 665) 43428 * TARGET_EXPAND_BUILTIN_SAVEREGS: Varargs. (line 92) 43429 * TARGET_EXPAND_TO_RTL_HOOK: Storage Layout. (line 519) 43430 * TARGET_EXPR: Expression trees. (line 6) 43431 * TARGET_EXTRA_INCLUDES: Misc. (line 847) 43432 * TARGET_EXTRA_LIVE_ON_ENTRY: Tail Calls. (line 21) 43433 * TARGET_EXTRA_PRE_INCLUDES: Misc. (line 854) 43434 * TARGET_FIXED_CONDITION_CODE_REGS: Condition Code. (line 142) 43435 * TARGET_FIXED_POINT_SUPPORTED_P: Storage Layout. (line 516) 43436 * target_flags: Run-time Target. (line 52) 43437 * TARGET_FLT_EVAL_METHOD: Type Layout. (line 141) 43438 * TARGET_FN_ABI_VA_LIST: Register Arguments. (line 268) 43439 * TARGET_FOLD_BUILTIN: Misc. (line 685) 43440 * TARGET_FORMAT_TYPES: Misc. (line 874) 43441 * TARGET_FUNCTION_ATTRIBUTE_INLINABLE_P: Target Attributes. (line 86) 43442 * TARGET_FUNCTION_OK_FOR_SIBCALL: Tail Calls. (line 8) 43443 * TARGET_FUNCTION_VALUE: Scalar Return. (line 11) 43444 * TARGET_GET_DRAP_RTX: Misc. (line 954) 43445 * TARGET_GIMPLIFY_VA_ARG_EXPR: Register Arguments. (line 279) 43446 * TARGET_HANDLE_C_OPTION: Run-time Target. (line 78) 43447 * TARGET_HANDLE_OPTION: Run-time Target. (line 61) 43448 * TARGET_HARD_REGNO_SCRATCH_OK: Values in Registers. 43449 (line 144) 43450 * TARGET_HAS_SINCOS: Library Calls. (line 85) 43451 * TARGET_HAVE_CONDITIONAL_EXECUTION: Misc. (line 830) 43452 * TARGET_HAVE_CTORS_DTORS: Macros for Initialization. 43453 (line 64) 43454 * TARGET_HAVE_NAMED_SECTIONS: File Framework. (line 99) 43455 * TARGET_HAVE_SWITCHABLE_BSS_SECTIONS: File Framework. (line 103) 43456 * TARGET_HELP: Run-time Target. (line 140) 43457 * TARGET_IN_SMALL_DATA_P: Sections. (line 276) 43458 * TARGET_INIT_BUILTINS: Misc. (line 647) 43459 * TARGET_INIT_DWARF_REG_SIZES_EXTRA: Exception Region Output. 43460 (line 99) 43461 * TARGET_INIT_LIBFUNCS: Library Calls. (line 16) 43462 * TARGET_INSERT_ATTRIBUTES: Target Attributes. (line 73) 43463 * TARGET_INSTANTIATE_DECLS: Storage Layout. (line 527) 43464 * TARGET_INVALID_BINARY_OP: Misc. (line 927) 43465 * TARGET_INVALID_CONVERSION: Misc. (line 914) 43466 * TARGET_INVALID_UNARY_OP: Misc. (line 920) 43467 * TARGET_IRA_COVER_CLASSES: Register Classes. (line 496) 43468 * TARGET_LIB_INT_CMP_BIASED: Library Calls. (line 35) 43469 * TARGET_LIBGCC_CMP_RETURN_MODE: Storage Layout. (line 448) 43470 * TARGET_LIBGCC_SDATA_SECTION: Sections. (line 123) 43471 * TARGET_LIBGCC_SHIFT_COUNT_MODE: Storage Layout. (line 454) 43472 * TARGET_MACHINE_DEPENDENT_REORG: Misc. (line 632) 43473 * TARGET_MANGLE_DECL_ASSEMBLER_NAME: Sections. (line 225) 43474 * TARGET_MANGLE_TYPE: Storage Layout. (line 531) 43475 * TARGET_MD_ASM_CLOBBERS: Misc. (line 548) 43476 * TARGET_MEM_CONSTRAINT: Addressing Modes. (line 100) 43477 * TARGET_MEM_REF: Expression trees. (line 6) 43478 * TARGET_MERGE_DECL_ATTRIBUTES: Target Attributes. (line 39) 43479 * TARGET_MERGE_TYPE_ATTRIBUTES: Target Attributes. (line 31) 43480 * TARGET_MIN_DIVISIONS_FOR_RECIP_MUL: Misc. (line 106) 43481 * TARGET_MODE_REP_EXTENDED: Misc. (line 191) 43482 * TARGET_MS_BITFIELD_LAYOUT_P: Storage Layout. (line 486) 43483 * TARGET_MUST_PASS_IN_STACK: Register Arguments. (line 62) 43484 * TARGET_MUST_PASS_IN_STACK, and FUNCTION_ARG: Register Arguments. 43485 (line 52) 43486 * TARGET_N_FORMAT_TYPES: Misc. (line 879) 43487 * TARGET_NARROW_VOLATILE_BITFIELD: Storage Layout. (line 392) 43488 * TARGET_OBJECT_SUFFIX: Misc. (line 764) 43489 * TARGET_OBJFMT_CPP_BUILTINS: Run-time Target. (line 46) 43490 * TARGET_OPTF: Misc. (line 861) 43491 * TARGET_OPTION_PRAGMA_PARSE: Target Attributes. (line 120) 43492 * TARGET_OPTION_PRINT: Target Attributes. (line 115) 43493 * TARGET_OPTION_RESTORE: Target Attributes. (line 110) 43494 * TARGET_OPTION_SAVE: Target Attributes. (line 104) 43495 * TARGET_OPTION_TRANSLATE_TABLE: Driver. (line 53) 43496 * TARGET_OS_CPP_BUILTINS: Run-time Target. (line 42) 43497 * TARGET_OVERRIDES_FORMAT_ATTRIBUTES: Misc. (line 883) 43498 * TARGET_OVERRIDES_FORMAT_ATTRIBUTES_COUNT: Misc. (line 889) 43499 * TARGET_OVERRIDES_FORMAT_INIT: Misc. (line 893) 43500 * TARGET_PASS_BY_REFERENCE: Register Arguments. (line 103) 43501 * TARGET_POSIX_IO: Misc. (line 572) 43502 * TARGET_PRETEND_OUTGOING_VARARGS_NAMED: Varargs. (line 152) 43503 * TARGET_PROMOTE_FUNCTION_ARGS: Storage Layout. (line 131) 43504 * TARGET_PROMOTE_FUNCTION_RETURN: Storage Layout. (line 136) 43505 * TARGET_PROMOTE_PROTOTYPES: Stack Arguments. (line 11) 43506 * TARGET_PTRMEMFUNC_VBIT_LOCATION: Type Layout. (line 235) 43507 * TARGET_RELAXED_ORDERING: Misc. (line 898) 43508 * TARGET_RESOLVE_OVERLOADED_BUILTIN: Misc. (line 675) 43509 * TARGET_RETURN_IN_MEMORY: Aggregate Return. (line 16) 43510 * TARGET_RETURN_IN_MSB: Scalar Return. (line 100) 43511 * TARGET_RTX_COSTS: Costs. (line 210) 43512 * TARGET_SCALAR_MODE_SUPPORTED_P: Register Arguments. (line 291) 43513 * TARGET_SCHED_ADJUST_COST: Scheduling. (line 37) 43514 * TARGET_SCHED_ADJUST_PRIORITY: Scheduling. (line 52) 43515 * TARGET_SCHED_CLEAR_SCHED_CONTEXT: Scheduling. (line 283) 43516 * TARGET_SCHED_DEPENDENCIES_EVALUATION_HOOK: Scheduling. (line 89) 43517 * TARGET_SCHED_DFA_NEW_CYCLE: Scheduling. (line 205) 43518 * TARGET_SCHED_DFA_POST_CYCLE_ADVANCE: Scheduling. (line 160) 43519 * TARGET_SCHED_DFA_POST_CYCLE_INSN: Scheduling. (line 144) 43520 * TARGET_SCHED_DFA_PRE_CYCLE_ADVANCE: Scheduling. (line 153) 43521 * TARGET_SCHED_DFA_PRE_CYCLE_INSN: Scheduling. (line 132) 43522 * TARGET_SCHED_FINISH: Scheduling. (line 109) 43523 * TARGET_SCHED_FINISH_GLOBAL: Scheduling. (line 126) 43524 * TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD: Scheduling. 43525 (line 168) 43526 * TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD_GUARD: Scheduling. 43527 (line 196) 43528 * TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD_GUARD_SPEC: Scheduling. 43529 (line 321) 43530 * TARGET_SCHED_FREE_SCHED_CONTEXT: Scheduling. (line 287) 43531 * TARGET_SCHED_GEN_CHECK: Scheduling. (line 309) 43532 * TARGET_SCHED_H_I_D_EXTENDED: Scheduling. (line 241) 43533 * TARGET_SCHED_INIT: Scheduling. (line 99) 43534 * TARGET_SCHED_INIT_DFA_POST_CYCLE_INSN: Scheduling. (line 149) 43535 * TARGET_SCHED_INIT_DFA_PRE_CYCLE_INSN: Scheduling. (line 141) 43536 * TARGET_SCHED_INIT_GLOBAL: Scheduling. (line 118) 43537 * TARGET_SCHED_INIT_SCHED_CONTEXT: Scheduling. (line 273) 43538 * TARGET_SCHED_IS_COSTLY_DEPENDENCE: Scheduling. (line 219) 43539 * TARGET_SCHED_ISSUE_RATE: Scheduling. (line 12) 43540 * TARGET_SCHED_NEEDS_BLOCK_P: Scheduling. (line 302) 43541 * TARGET_SCHED_REORDER: Scheduling. (line 60) 43542 * TARGET_SCHED_REORDER2: Scheduling. (line 77) 43543 * TARGET_SCHED_SET_SCHED_CONTEXT: Scheduling. (line 279) 43544 * TARGET_SCHED_SET_SCHED_FLAGS: Scheduling. (line 332) 43545 * TARGET_SCHED_SMS_RES_MII: Scheduling. (line 343) 43546 * TARGET_SCHED_SPECULATE_INSN: Scheduling. (line 291) 43547 * TARGET_SCHED_VARIABLE_ISSUE: Scheduling. (line 24) 43548 * TARGET_SECONDARY_RELOAD: Register Classes. (line 257) 43549 * TARGET_SECTION_TYPE_FLAGS: File Framework. (line 109) 43550 * TARGET_SET_CURRENT_FUNCTION: Misc. (line 747) 43551 * TARGET_SET_DEFAULT_TYPE_ATTRIBUTES: Target Attributes. (line 26) 43552 * TARGET_SETUP_INCOMING_VARARGS: Varargs. (line 101) 43553 * TARGET_SHIFT_TRUNCATION_MASK: Misc. (line 154) 43554 * TARGET_SPLIT_COMPLEX_ARG: Register Arguments. (line 252) 43555 * TARGET_STACK_PROTECT_FAIL: Stack Smashing Protection. 43556 (line 17) 43557 * TARGET_STACK_PROTECT_GUARD: Stack Smashing Protection. 43558 (line 7) 43559 * TARGET_STRICT_ARGUMENT_NAMING: Varargs. (line 137) 43560 * TARGET_STRUCT_VALUE_RTX: Aggregate Return. (line 44) 43561 * TARGET_UNSPEC_MAY_TRAP_P: Misc. (line 739) 43562 * TARGET_UNWIND_EMIT: Dispatch Tables. (line 81) 43563 * TARGET_UNWIND_INFO: Exception Region Output. 43564 (line 56) 43565 * TARGET_UPDATE_STACK_BOUNDARY: Misc. (line 950) 43566 * TARGET_USE_ANCHORS_FOR_SYMBOL_P: Anchored Addresses. (line 55) 43567 * TARGET_USE_BLOCKS_FOR_CONSTANT_P: Addressing Modes. (line 233) 43568 * TARGET_USE_JCR_SECTION: Misc. (line 932) 43569 * TARGET_USE_LOCAL_THUNK_ALIAS_P: Misc. (line 867) 43570 * TARGET_USES_WEAK_UNWIND_INFO: Exception Handling. (line 129) 43571 * TARGET_VALID_DLLIMPORT_ATTRIBUTE_P: Target Attributes. (line 59) 43572 * TARGET_VALID_OPTION_ATTRIBUTE_P: Target Attributes. (line 93) 43573 * TARGET_VALID_POINTER_MODE: Register Arguments. (line 285) 43574 * TARGET_VECTOR_MODE_SUPPORTED_P: Register Arguments. (line 303) 43575 * TARGET_VECTOR_OPAQUE_P: Storage Layout. (line 479) 43576 * TARGET_VECTORIZE_BUILTIN_CONVERSION: Addressing Modes. (line 300) 43577 * TARGET_VECTORIZE_BUILTIN_MASK_FOR_LOAD: Addressing Modes. (line 249) 43578 * TARGET_VECTORIZE_BUILTIN_MUL_WIDEN_EVEN: Addressing Modes. (line 275) 43579 * TARGET_VECTORIZE_BUILTIN_MUL_WIDEN_ODD: Addressing Modes. (line 287) 43580 * TARGET_VECTORIZE_BUILTIN_VECTORIZED_FUNCTION: Addressing Modes. 43581 (line 315) 43582 * TARGET_VERSION: Run-time Target. (line 91) 43583 * TARGET_VTABLE_DATA_ENTRY_DISTANCE: Type Layout. (line 288) 43584 * TARGET_VTABLE_ENTRY_ALIGN: Type Layout. (line 282) 43585 * TARGET_VTABLE_USES_DESCRIPTORS: Type Layout. (line 271) 43586 * TARGET_WEAK_NOT_IN_ARCHIVE_TOC: Label Output. (line 245) 43587 * targetm: Target Structure. (line 7) 43588 * targets, makefile: Makefile. (line 6) 43589 * TCmode: Machine Modes. (line 197) 43590 * TDmode: Machine Modes. (line 94) 43591 * TEMPLATE_DECL: Declarations. (line 6) 43592 * Temporaries: Temporaries. (line 6) 43593 * termination routines: Initialization. (line 6) 43594 * testing constraints: C Constraint Interface. 43595 (line 6) 43596 * TEXT_SECTION_ASM_OP: Sections. (line 38) 43597 * TF_SIZE: Type Layout. (line 132) 43598 * TFmode: Machine Modes. (line 98) 43599 * THEN_CLAUSE: Function Bodies. (line 6) 43600 * THREAD_MODEL_SPEC: Driver. (line 225) 43601 * THROW_EXPR: Expression trees. (line 6) 43602 * THUNK_DECL: Declarations. (line 6) 43603 * THUNK_DELTA: Declarations. (line 6) 43604 * TImode: Machine Modes. (line 48) 43605 * TImode, in insn: Insns. (line 231) 43606 * tm.h macros: Target Macros. (line 6) 43607 * TQFmode: Machine Modes. (line 62) 43608 * TQmode: Machine Modes. (line 119) 43609 * TRAMPOLINE_ADJUST_ADDRESS: Trampolines. (line 62) 43610 * TRAMPOLINE_ALIGNMENT: Trampolines. (line 49) 43611 * TRAMPOLINE_SECTION: Trampolines. (line 40) 43612 * TRAMPOLINE_SIZE: Trampolines. (line 45) 43613 * TRAMPOLINE_TEMPLATE: Trampolines. (line 29) 43614 * trampolines for nested functions: Trampolines. (line 6) 43615 * TRANSFER_FROM_TRAMPOLINE: Trampolines. (line 124) 43616 * trap instruction pattern: Standard Names. (line 1374) 43617 * tree <1>: Macros and Functions. 43618 (line 6) 43619 * tree: Tree overview. (line 6) 43620 * Tree SSA: Tree SSA. (line 6) 43621 * tree_code <1>: GIMPLE_COND. (line 21) 43622 * tree_code <2>: Manipulating GIMPLE statements. 43623 (line 31) 43624 * tree_code <3>: GIMPLE_ASSIGN. (line 41) 43625 * tree_code: GIMPLE_OMP_FOR. (line 83) 43626 * TREE_CODE: Tree overview. (line 6) 43627 * TREE_FILENAME: Working with declarations. 43628 (line 14) 43629 * tree_int_cst_equal: Expression trees. (line 6) 43630 * TREE_INT_CST_HIGH: Expression trees. (line 6) 43631 * TREE_INT_CST_LOW: Expression trees. (line 6) 43632 * tree_int_cst_lt: Expression trees. (line 6) 43633 * TREE_LINENO: Working with declarations. 43634 (line 20) 43635 * TREE_LIST: Containers. (line 6) 43636 * TREE_OPERAND: Expression trees. (line 6) 43637 * TREE_PUBLIC: Function Basics. (line 41) 43638 * TREE_PURPOSE: Containers. (line 6) 43639 * TREE_STRING_LENGTH: Expression trees. (line 6) 43640 * TREE_STRING_POINTER: Expression trees. (line 6) 43641 * TREE_TYPE <1>: Working with declarations. 43642 (line 11) 43643 * TREE_TYPE <2>: Expression trees. (line 17) 43644 * TREE_TYPE <3>: Types. (line 6) 43645 * TREE_TYPE <4>: Expression trees. (line 6) 43646 * TREE_TYPE: Function Basics. (line 171) 43647 * TREE_VALUE: Containers. (line 6) 43648 * TREE_VEC: Containers. (line 6) 43649 * TREE_VEC_ELT: Containers. (line 6) 43650 * TREE_VEC_LENGTH: Containers. (line 6) 43651 * Trees: Trees. (line 6) 43652 * TRULY_NOOP_TRUNCATION: Misc. (line 177) 43653 * TRUNC_DIV_EXPR: Expression trees. (line 6) 43654 * TRUNC_MOD_EXPR: Expression trees. (line 6) 43655 * truncate: Conversions. (line 38) 43656 * truncMN2 instruction pattern: Standard Names. (line 821) 43657 * TRUTH_AND_EXPR: Expression trees. (line 6) 43658 * TRUTH_ANDIF_EXPR: Expression trees. (line 6) 43659 * TRUTH_NOT_EXPR: Expression trees. (line 6) 43660 * TRUTH_OR_EXPR: Expression trees. (line 6) 43661 * TRUTH_ORIF_EXPR: Expression trees. (line 6) 43662 * TRUTH_XOR_EXPR: Expression trees. (line 6) 43663 * TRY_BLOCK: Function Bodies. (line 6) 43664 * TRY_HANDLERS: Function Bodies. (line 6) 43665 * TRY_STMTS: Function Bodies. (line 6) 43666 * tstM instruction pattern: Standard Names. (line 661) 43667 * Tuple specific accessors: Tuple specific accessors. 43668 (line 6) 43669 * tuples: Tuple representation. 43670 (line 6) 43671 * type: Types. (line 6) 43672 * type declaration: Declarations. (line 6) 43673 * TYPE_ALIGN: Types. (line 6) 43674 * TYPE_ARG_TYPES: Types. (line 6) 43675 * TYPE_ASM_OP: Label Output. (line 55) 43676 * TYPE_ATTRIBUTES: Attributes. (line 25) 43677 * TYPE_BINFO: Classes. (line 6) 43678 * TYPE_BUILT_IN: Types. (line 83) 43679 * TYPE_CANONICAL: Types. (line 6) 43680 * TYPE_CONTEXT: Types. (line 6) 43681 * TYPE_DECL: Declarations. (line 6) 43682 * TYPE_FIELDS <1>: Classes. (line 6) 43683 * TYPE_FIELDS: Types. (line 6) 43684 * TYPE_HAS_ARRAY_NEW_OPERATOR: Classes. (line 91) 43685 * TYPE_HAS_DEFAULT_CONSTRUCTOR: Classes. (line 76) 43686 * TYPE_HAS_MUTABLE_P: Classes. (line 81) 43687 * TYPE_HAS_NEW_OPERATOR: Classes. (line 88) 43688 * TYPE_MAIN_VARIANT: Types. (line 6) 43689 * TYPE_MAX_VALUE: Types. (line 6) 43690 * TYPE_METHOD_BASETYPE: Types. (line 6) 43691 * TYPE_METHODS: Classes. (line 6) 43692 * TYPE_MIN_VALUE: Types. (line 6) 43693 * TYPE_NAME: Types. (line 6) 43694 * TYPE_NOTHROW_P: Function Basics. (line 180) 43695 * TYPE_OFFSET_BASETYPE: Types. (line 6) 43696 * TYPE_OPERAND_FMT: Label Output. (line 66) 43697 * TYPE_OVERLOADS_ARRAY_REF: Classes. (line 99) 43698 * TYPE_OVERLOADS_ARROW: Classes. (line 102) 43699 * TYPE_OVERLOADS_CALL_EXPR: Classes. (line 95) 43700 * TYPE_POLYMORPHIC_P: Classes. (line 72) 43701 * TYPE_PRECISION: Types. (line 6) 43702 * TYPE_PTR_P: Types. (line 89) 43703 * TYPE_PTRFN_P: Types. (line 93) 43704 * TYPE_PTRMEM_P: Types. (line 86) 43705 * TYPE_PTROB_P: Types. (line 96) 43706 * TYPE_PTROBV_P: Types. (line 6) 43707 * TYPE_QUAL_CONST: Types. (line 6) 43708 * TYPE_QUAL_RESTRICT: Types. (line 6) 43709 * TYPE_QUAL_VOLATILE: Types. (line 6) 43710 * TYPE_RAISES_EXCEPTIONS: Function Basics. (line 175) 43711 * TYPE_SIZE: Types. (line 6) 43712 * TYPE_STRUCTURAL_EQUALITY_P: Types. (line 6) 43713 * TYPE_UNQUALIFIED: Types. (line 6) 43714 * TYPE_VFIELD: Classes. (line 6) 43715 * TYPENAME_TYPE: Types. (line 6) 43716 * TYPENAME_TYPE_FULLNAME: Types. (line 6) 43717 * TYPEOF_TYPE: Types. (line 6) 43718 * UDAmode: Machine Modes. (line 168) 43719 * udiv: Arithmetic. (line 125) 43720 * udivM3 instruction pattern: Standard Names. (line 222) 43721 * udivmodM4 instruction pattern: Standard Names. (line 428) 43722 * udot_prodM instruction pattern: Standard Names. (line 265) 43723 * UDQmode: Machine Modes. (line 136) 43724 * UHAmode: Machine Modes. (line 160) 43725 * UHQmode: Machine Modes. (line 128) 43726 * UINTMAX_TYPE: Type Layout. (line 224) 43727 * umaddMN4 instruction pattern: Standard Names. (line 375) 43728 * umax: Arithmetic. (line 144) 43729 * umaxM3 instruction pattern: Standard Names. (line 222) 43730 * umin: Arithmetic. (line 144) 43731 * uminM3 instruction pattern: Standard Names. (line 222) 43732 * umod: Arithmetic. (line 131) 43733 * umodM3 instruction pattern: Standard Names. (line 222) 43734 * umsubMN4 instruction pattern: Standard Names. (line 399) 43735 * umulhisi3 instruction pattern: Standard Names. (line 347) 43736 * umulM3_highpart instruction pattern: Standard Names. (line 361) 43737 * umulqihi3 instruction pattern: Standard Names. (line 347) 43738 * umulsidi3 instruction pattern: Standard Names. (line 347) 43739 * unchanging: Flags. (line 319) 43740 * unchanging, in call_insn: Flags. (line 19) 43741 * unchanging, in jump_insn, call_insn and insn: Flags. (line 39) 43742 * unchanging, in mem: Flags. (line 152) 43743 * unchanging, in subreg: Flags. (line 198) 43744 * unchanging, in symbol_ref: Flags. (line 10) 43745 * UNEQ_EXPR: Expression trees. (line 6) 43746 * UNGE_EXPR: Expression trees. (line 6) 43747 * UNGT_EXPR: Expression trees. (line 6) 43748 * UNION_TYPE <1>: Classes. (line 6) 43749 * UNION_TYPE: Types. (line 6) 43750 * unions, returning: Interface. (line 10) 43751 * UNITS_PER_SIMD_WORD: Storage Layout. (line 77) 43752 * UNITS_PER_WORD: Storage Layout. (line 67) 43753 * UNKNOWN_TYPE: Types. (line 6) 43754 * UNLE_EXPR: Expression trees. (line 6) 43755 * UNLIKELY_EXECUTED_TEXT_SECTION_NAME: Sections. (line 49) 43756 * UNLT_EXPR: Expression trees. (line 6) 43757 * UNORDERED_EXPR: Expression trees. (line 6) 43758 * unshare_all_rtl: Sharing. (line 58) 43759 * unsigned division: Arithmetic. (line 125) 43760 * unsigned division with unsigned saturation: Arithmetic. (line 125) 43761 * unsigned greater than: Comparisons. (line 72) 43762 * unsigned less than: Comparisons. (line 68) 43763 * unsigned minimum and maximum: Arithmetic. (line 144) 43764 * unsigned_fix: Conversions. (line 77) 43765 * unsigned_float: Conversions. (line 62) 43766 * unsigned_fract_convert: Conversions. (line 97) 43767 * unsigned_sat_fract: Conversions. (line 103) 43768 * unspec: Side Effects. (line 287) 43769 * unspec_volatile: Side Effects. (line 287) 43770 * untyped_call instruction pattern: Standard Names. (line 1012) 43771 * untyped_return instruction pattern: Standard Names. (line 1062) 43772 * UPDATE_PATH_HOST_CANONICALIZE (PATH): Filesystem. (line 59) 43773 * update_ssa: SSA. (line 76) 43774 * update_stmt <1>: Manipulating GIMPLE statements. 43775 (line 141) 43776 * update_stmt: SSA Operands. (line 6) 43777 * update_stmt_if_modified: Manipulating GIMPLE statements. 43778 (line 144) 43779 * UQQmode: Machine Modes. (line 123) 43780 * US Software GOFAST, floating point emulation library: Library Calls. 43781 (line 44) 43782 * us_ashift: Arithmetic. (line 168) 43783 * us_minus: Arithmetic. (line 36) 43784 * us_mult: Arithmetic. (line 92) 43785 * us_neg: Arithmetic. (line 81) 43786 * us_plus: Arithmetic. (line 14) 43787 * US_SOFTWARE_GOFAST: Library Calls. (line 45) 43788 * us_truncate: Conversions. (line 48) 43789 * usaddM3 instruction pattern: Standard Names. (line 222) 43790 * USAmode: Machine Modes. (line 164) 43791 * usashlM3 instruction pattern: Standard Names. (line 431) 43792 * usdivM3 instruction pattern: Standard Names. (line 222) 43793 * use: Side Effects. (line 162) 43794 * USE_C_ALLOCA: Host Misc. (line 19) 43795 * USE_LD_AS_NEEDED: Driver. (line 198) 43796 * USE_LOAD_POST_DECREMENT: Costs. (line 165) 43797 * USE_LOAD_POST_INCREMENT: Costs. (line 160) 43798 * USE_LOAD_PRE_DECREMENT: Costs. (line 175) 43799 * USE_LOAD_PRE_INCREMENT: Costs. (line 170) 43800 * use_optype_d: Manipulating GIMPLE statements. 43801 (line 101) 43802 * use_param: GTY Options. (line 114) 43803 * use_paramN: GTY Options. (line 132) 43804 * use_params: GTY Options. (line 140) 43805 * USE_SELECT_SECTION_FOR_FUNCTIONS: Sections. (line 185) 43806 * USE_STORE_POST_DECREMENT: Costs. (line 185) 43807 * USE_STORE_POST_INCREMENT: Costs. (line 180) 43808 * USE_STORE_PRE_DECREMENT: Costs. (line 195) 43809 * USE_STORE_PRE_INCREMENT: Costs. (line 190) 43810 * used: Flags. (line 337) 43811 * used, in symbol_ref: Flags. (line 215) 43812 * USER_LABEL_PREFIX: Instruction Output. (line 126) 43813 * USING_DECL: Declarations. (line 6) 43814 * USING_STMT: Function Bodies. (line 6) 43815 * usmaddMN4 instruction pattern: Standard Names. (line 383) 43816 * usmsubMN4 instruction pattern: Standard Names. (line 407) 43817 * usmulhisi3 instruction pattern: Standard Names. (line 351) 43818 * usmulM3 instruction pattern: Standard Names. (line 222) 43819 * usmulqihi3 instruction pattern: Standard Names. (line 351) 43820 * usmulsidi3 instruction pattern: Standard Names. (line 351) 43821 * usnegM2 instruction pattern: Standard Names. (line 449) 43822 * USQmode: Machine Modes. (line 132) 43823 * ussubM3 instruction pattern: Standard Names. (line 222) 43824 * usum_widenM3 instruction pattern: Standard Names. (line 275) 43825 * UTAmode: Machine Modes. (line 172) 43826 * UTQmode: Machine Modes. (line 140) 43827 * V in constraint: Simple Constraints. (line 43) 43828 * VA_ARG_EXPR: Expression trees. (line 6) 43829 * values, returned by functions: Scalar Return. (line 6) 43830 * VAR_DECL <1>: Declarations. (line 6) 43831 * VAR_DECL: Expression trees. (line 6) 43832 * varargs implementation: Varargs. (line 6) 43833 * variable: Declarations. (line 6) 43834 * vashlM3 instruction pattern: Standard Names. (line 445) 43835 * vashrM3 instruction pattern: Standard Names. (line 445) 43836 * vec_concat: Vector Operations. (line 25) 43837 * vec_duplicate: Vector Operations. (line 30) 43838 * VEC_EXTRACT_EVEN_EXPR: Expression trees. (line 6) 43839 * vec_extract_evenM instruction pattern: Standard Names. (line 176) 43840 * VEC_EXTRACT_ODD_EXPR: Expression trees. (line 6) 43841 * vec_extract_oddM instruction pattern: Standard Names. (line 183) 43842 * vec_extractM instruction pattern: Standard Names. (line 171) 43843 * vec_initM instruction pattern: Standard Names. (line 204) 43844 * VEC_INTERLEAVE_HIGH_EXPR: Expression trees. (line 6) 43845 * vec_interleave_highM instruction pattern: Standard Names. (line 190) 43846 * VEC_INTERLEAVE_LOW_EXPR: Expression trees. (line 6) 43847 * vec_interleave_lowM instruction pattern: Standard Names. (line 197) 43848 * VEC_LSHIFT_EXPR: Expression trees. (line 6) 43849 * vec_merge: Vector Operations. (line 11) 43850 * VEC_PACK_FIX_TRUNC_EXPR: Expression trees. (line 6) 43851 * VEC_PACK_SAT_EXPR: Expression trees. (line 6) 43852 * vec_pack_sfix_trunc_M instruction pattern: Standard Names. (line 302) 43853 * vec_pack_ssat_M instruction pattern: Standard Names. (line 295) 43854 * VEC_PACK_TRUNC_EXPR: Expression trees. (line 6) 43855 * vec_pack_trunc_M instruction pattern: Standard Names. (line 288) 43856 * vec_pack_ufix_trunc_M instruction pattern: Standard Names. (line 302) 43857 * vec_pack_usat_M instruction pattern: Standard Names. (line 295) 43858 * VEC_RSHIFT_EXPR: Expression trees. (line 6) 43859 * vec_select: Vector Operations. (line 19) 43860 * vec_setM instruction pattern: Standard Names. (line 166) 43861 * vec_shl_M instruction pattern: Standard Names. (line 282) 43862 * vec_shr_M instruction pattern: Standard Names. (line 282) 43863 * VEC_UNPACK_FLOAT_HI_EXPR: Expression trees. (line 6) 43864 * VEC_UNPACK_FLOAT_LO_EXPR: Expression trees. (line 6) 43865 * VEC_UNPACK_HI_EXPR: Expression trees. (line 6) 43866 * VEC_UNPACK_LO_EXPR: Expression trees. (line 6) 43867 * vec_unpacks_float_hi_M instruction pattern: Standard Names. 43868 (line 324) 43869 * vec_unpacks_float_lo_M instruction pattern: Standard Names. 43870 (line 324) 43871 * vec_unpacks_hi_M instruction pattern: Standard Names. (line 309) 43872 * vec_unpacks_lo_M instruction pattern: Standard Names. (line 309) 43873 * vec_unpacku_float_hi_M instruction pattern: Standard Names. 43874 (line 324) 43875 * vec_unpacku_float_lo_M instruction pattern: Standard Names. 43876 (line 324) 43877 * vec_unpacku_hi_M instruction pattern: Standard Names. (line 317) 43878 * vec_unpacku_lo_M instruction pattern: Standard Names. (line 317) 43879 * VEC_WIDEN_MULT_HI_EXPR: Expression trees. (line 6) 43880 * VEC_WIDEN_MULT_LO_EXPR: Expression trees. (line 6) 43881 * vec_widen_smult_hi_M instruction pattern: Standard Names. (line 333) 43882 * vec_widen_smult_lo_M instruction pattern: Standard Names. (line 333) 43883 * vec_widen_umult_hi_M instruction pattern: Standard Names. (line 333) 43884 * vec_widen_umult_lo__M instruction pattern: Standard Names. (line 333) 43885 * vector: Containers. (line 6) 43886 * vector operations: Vector Operations. (line 6) 43887 * VECTOR_CST: Expression trees. (line 6) 43888 * VECTOR_STORE_FLAG_VALUE: Misc. (line 308) 43889 * virtual operands: SSA Operands. (line 6) 43890 * VIRTUAL_INCOMING_ARGS_REGNUM: Regs and Memory. (line 59) 43891 * VIRTUAL_OUTGOING_ARGS_REGNUM: Regs and Memory. (line 87) 43892 * VIRTUAL_STACK_DYNAMIC_REGNUM: Regs and Memory. (line 78) 43893 * VIRTUAL_STACK_VARS_REGNUM: Regs and Memory. (line 69) 43894 * VLIW: Processor pipeline description. 43895 (line 6) 43896 * vlshrM3 instruction pattern: Standard Names. (line 445) 43897 * VMS: Filesystem. (line 37) 43898 * VMS_DEBUGGING_INFO: VMS Debug. (line 9) 43899 * VOID_TYPE: Types. (line 6) 43900 * VOIDmode: Machine Modes. (line 190) 43901 * volatil: Flags. (line 351) 43902 * volatil, in insn, call_insn, jump_insn, code_label, barrier, and note: Flags. 43903 (line 44) 43904 * volatil, in label_ref and reg_label: Flags. (line 65) 43905 * volatil, in mem, asm_operands, and asm_input: Flags. (line 94) 43906 * volatil, in reg: Flags. (line 116) 43907 * volatil, in subreg: Flags. (line 188) 43908 * volatil, in symbol_ref: Flags. (line 224) 43909 * volatile memory references: Flags. (line 352) 43910 * voptype_d: Manipulating GIMPLE statements. 43911 (line 115) 43912 * voting between constraint alternatives: Class Preferences. (line 6) 43913 * vrotlM3 instruction pattern: Standard Names. (line 445) 43914 * vrotrM3 instruction pattern: Standard Names. (line 445) 43915 * walk_dominator_tree: SSA. (line 256) 43916 * walk_gimple_op: Statement and operand traversals. 43917 (line 32) 43918 * walk_gimple_seq: Statement and operand traversals. 43919 (line 50) 43920 * walk_gimple_stmt: Statement and operand traversals. 43921 (line 13) 43922 * walk_use_def_chains: SSA. (line 232) 43923 * WCHAR_TYPE: Type Layout. (line 192) 43924 * WCHAR_TYPE_SIZE: Type Layout. (line 200) 43925 * which_alternative: Output Statement. (line 59) 43926 * WHILE_BODY: Function Bodies. (line 6) 43927 * WHILE_COND: Function Bodies. (line 6) 43928 * WHILE_STMT: Function Bodies. (line 6) 43929 * WIDEST_HARDWARE_FP_SIZE: Type Layout. (line 147) 43930 * WINT_TYPE: Type Layout. (line 205) 43931 * word_mode: Machine Modes. (line 336) 43932 * WORD_REGISTER_OPERATIONS: Misc. (line 63) 43933 * WORD_SWITCH_TAKES_ARG: Driver. (line 20) 43934 * WORDS_BIG_ENDIAN: Storage Layout. (line 29) 43935 * WORDS_BIG_ENDIAN, effect on subreg: Regs and Memory. (line 217) 43936 * X in constraint: Simple Constraints. (line 114) 43937 * x-HOST: Host Fragment. (line 6) 43938 * XCmode: Machine Modes. (line 197) 43939 * XCOFF_DEBUGGING_INFO: DBX Options. (line 13) 43940 * XEXP: Accessors. (line 6) 43941 * XF_SIZE: Type Layout. (line 131) 43942 * XFmode: Machine Modes. (line 79) 43943 * XINT: Accessors. (line 6) 43944 * xm-MACHINE.h <1>: Filesystem. (line 6) 43945 * xm-MACHINE.h: Host Misc. (line 6) 43946 * xor: Arithmetic. (line 163) 43947 * xor, canonicalization of: Insn Canonicalizations. 43948 (line 84) 43949 * xorM3 instruction pattern: Standard Names. (line 222) 43950 * XSTR: Accessors. (line 6) 43951 * XVEC: Accessors. (line 41) 43952 * XVECEXP: Accessors. (line 48) 43953 * XVECLEN: Accessors. (line 44) 43954 * XWINT: Accessors. (line 6) 43955 * zero_extend: Conversions. (line 28) 43956 * zero_extendMN2 instruction pattern: Standard Names. (line 831) 43957 * zero_extract: Bit-Fields. (line 30) 43958 * zero_extract, canonicalization of: Insn Canonicalizations. 43959 (line 96) 43960 43961 43962 43963 Tag Table: 43964 Node: Top2076 43965 Node: Contributing5159 43966 Node: Portability5900 43967 Node: Interface7688 43968 Node: Libgcc10728 43969 Node: Integer library routines12569 43970 Node: Soft float library routines19408 43971 Node: Decimal float library routines31345 43972 Node: Fixed-point fractional library routines47102 43973 Node: Exception handling routines147500 43974 Node: Miscellaneous routines148607 43975 Node: Languages148990 43976 Node: Source Tree150537 43977 Node: Configure Terms151156 43978 Node: Top Level154114 43979 Node: gcc Directory156884 43980 Node: Subdirectories157853 43981 Node: Configuration159703 43982 Node: Config Fragments160423 43983 Node: System Config161652 43984 Node: Configuration Files162588 43985 Node: Build165163 43986 Node: Makefile165575 43987 Ref: Makefile-Footnote-1172293 43988 Ref: Makefile-Footnote-2172438 43989 Node: Library Files172510 43990 Node: Headers173072 43991 Node: Documentation175155 43992 Node: Texinfo Manuals176014 43993 Node: Man Page Generation178352 43994 Node: Miscellaneous Docs180267 43995 Node: Front End181566 43996 Node: Front End Directory185267 43997 Node: Front End Config190457 43998 Node: Back End193371 43999 Node: Testsuites197048 44000 Node: Test Idioms197912 44001 Node: Test Directives201313 44002 Node: Ada Tests213377 44003 Node: C Tests214669 44004 Node: libgcj Tests219024 44005 Node: gcov Testing220156 44006 Node: profopt Testing223140 44007 Node: compat Testing224583 44008 Node: Torture Tests228827 44009 Node: Options230459 44010 Node: Option file format230900 44011 Node: Option properties233649 44012 Node: Passes239705 44013 Node: Parsing pass240447 44014 Node: Gimplification pass243975 44015 Node: Pass manager245802 44016 Node: Tree-SSA passes247285 44017 Node: RTL passes269116 44018 Node: Trees281701 44019 Node: Deficiencies284427 44020 Node: Tree overview284664 44021 Node: Macros and Functions288787 44022 Node: Identifiers288933 44023 Node: Containers290458 44024 Node: Types291613 44025 Node: Scopes307316 44026 Node: Namespaces308078 44027 Node: Classes310890 44028 Node: Declarations315647 44029 Node: Working with declarations316142 44030 Node: Internal structure322599 44031 Node: Current structure hierarchy322981 44032 Node: Adding new DECL node types325073 44033 Node: Functions329144 44034 Node: Function Basics331547 44035 Node: Function Bodies339277 44036 Node: Attributes350519 44037 Node: Expression trees351760 44038 Node: RTL394369 44039 Node: RTL Objects396468 44040 Node: RTL Classes400342 44041 Node: Accessors405294 44042 Node: Special Accessors407688 44043 Node: Flags412906 44044 Node: Machine Modes428774 44045 Node: Constants441090 44046 Node: Regs and Memory447119 44047 Node: Arithmetic465020 44048 Node: Comparisons474540 44049 Node: Bit-Fields478832 44050 Node: Vector Operations480384 44051 Node: Conversions482010 44052 Node: RTL Declarations486508 44053 Node: Side Effects487329 44054 Node: Incdec503652 44055 Node: Assembler506987 44056 Node: Insns508519 44057 Node: Calls532408 44058 Node: Sharing535001 44059 Node: Reading RTL538111 44060 Node: GENERIC539101 44061 Node: Statements540738 44062 Node: Blocks541183 44063 Node: Statement Sequences542436 44064 Node: Empty Statements542769 44065 Node: Jumps543343 44066 Node: Cleanups543996 44067 Node: GIMPLE545749 44068 Node: Tuple representation549370 44069 Node: GIMPLE instruction set558025 44070 Node: GIMPLE Exception Handling559693 44071 Node: Temporaries561608 44072 Ref: Temporaries-Footnote-1562927 44073 Node: Operands562990 44074 Node: Compound Expressions563764 44075 Node: Compound Lvalues563998 44076 Node: Conditional Expressions564764 44077 Node: Logical Operators565434 44078 Node: Manipulating GIMPLE statements571525 44079 Node: Tuple specific accessors577453 44080 Node: `GIMPLE_ASM'578286 44081 Node: `GIMPLE_ASSIGN'580891 44082 Node: `GIMPLE_BIND'584837 44083 Node: `GIMPLE_CALL'586644 44084 Node: `GIMPLE_CATCH'590903 44085 Node: `GIMPLE_CHANGE_DYNAMIC_TYPE'592061 44086 Node: `GIMPLE_COND'593394 44087 Node: `GIMPLE_EH_FILTER'596200 44088 Node: `GIMPLE_LABEL'597686 44089 Node: `GIMPLE_NOP'598661 44090 Node: `GIMPLE_OMP_ATOMIC_LOAD'599030 44091 Node: `GIMPLE_OMP_ATOMIC_STORE'599940 44092 Node: `GIMPLE_OMP_CONTINUE'600579 44093 Node: `GIMPLE_OMP_CRITICAL'601929 44094 Node: `GIMPLE_OMP_FOR'602865 44095 Node: `GIMPLE_OMP_MASTER'606375 44096 Node: `GIMPLE_OMP_ORDERED'606758 44097 Node: `GIMPLE_OMP_PARALLEL'607158 44098 Node: `GIMPLE_OMP_RETURN'609927 44099 Node: `GIMPLE_OMP_SECTION'610577 44100 Node: `GIMPLE_OMP_SECTIONS'611243 44101 Node: `GIMPLE_OMP_SINGLE'612847 44102 Node: `GIMPLE_PHI'613783 44103 Node: `GIMPLE_RESX'615196 44104 Node: `GIMPLE_RETURN'615915 44105 Node: `GIMPLE_SWITCH'616483 44106 Node: `GIMPLE_TRY'618613 44107 Node: `GIMPLE_WITH_CLEANUP_EXPR'620403 44108 Node: GIMPLE sequences621286 44109 Node: Sequence iterators624492 44110 Node: Adding a new GIMPLE statement code632947 44111 Node: Statement and operand traversals634227 44112 Node: Tree SSA636837 44113 Node: Annotations638566 44114 Node: SSA Operands639092 44115 Node: SSA653623 44116 Node: Alias analysis665914 44117 Node: Loop Analysis and Representation673370 44118 Node: Loop representation674551 44119 Node: Loop querying681471 44120 Node: Loop manipulation684304 44121 Node: LCSSA686672 44122 Node: Scalar evolutions688744 44123 Node: loop-iv691988 44124 Node: Number of iterations693914 44125 Node: Dependency analysis696723 44126 Node: Lambda703091 44127 Node: Omega704761 44128 Node: Control Flow706326 44129 Node: Basic Blocks707326 44130 Node: Edges711894 44131 Node: Profile information720456 44132 Node: Maintaining the CFG725142 44133 Node: Liveness information732024 44134 Node: Machine Desc734151 44135 Node: Overview736619 44136 Node: Patterns738660 44137 Node: Example742098 44138 Node: RTL Template743533 44139 Node: Output Template754188 44140 Node: Output Statement758154 44141 Node: Predicates762116 44142 Node: Machine-Independent Predicates765034 44143 Node: Defining Predicates769666 44144 Node: Constraints775631 44145 Node: Simple Constraints776879 44146 Node: Multi-Alternative789085 44147 Node: Class Preferences791926 44148 Node: Modifiers792818 44149 Node: Machine Constraints796950 44150 Node: Disable Insn Alternatives829673 44151 Node: Define Constraints832566 44152 Node: C Constraint Interface839346 44153 Node: Standard Names842987 44154 Ref: shift patterns861915 44155 Ref: prologue instruction pattern902933 44156 Ref: epilogue instruction pattern903426 44157 Node: Pattern Ordering912969 44158 Node: Dependent Patterns914205 44159 Node: Jump Patterns917019 44160 Node: Looping Patterns922715 44161 Node: Insn Canonicalizations927443 44162 Node: Expander Definitions931827 44163 Node: Insn Splitting939945 44164 Node: Including Patterns949548 44165 Node: Peephole Definitions951328 44166 Node: define_peephole952581 44167 Node: define_peephole2958912 44168 Node: Insn Attributes961979 44169 Node: Defining Attributes963085 44170 Node: Expressions965605 44171 Node: Tagging Insns972207 44172 Node: Attr Example976560 44173 Node: Insn Lengths978934 44174 Node: Constant Attributes981993 44175 Node: Delay Slots983162 44176 Node: Processor pipeline description986386 44177 Ref: Processor pipeline description-Footnote-11003752 44178 Node: Conditional Execution1004074 44179 Node: Constant Definitions1006927 44180 Node: Iterators1008522 44181 Node: Mode Iterators1008969 44182 Node: Defining Mode Iterators1009947 44183 Node: Substitutions1011441 44184 Node: Examples1013682 44185 Node: Code Iterators1015130 44186 Node: Target Macros1017387 44187 Node: Target Structure1020410 44188 Node: Driver1021679 44189 Node: Run-time Target1045360 44190 Node: Per-Function Data1052484 44191 Node: Storage Layout1055247 44192 Node: Type Layout1080661 44193 Node: Registers1093618 44194 Node: Register Basics1094592 44195 Node: Allocation Order1100159 44196 Node: Values in Registers1102180 44197 Node: Leaf Functions1109669 44198 Node: Stack Registers1112527 44199 Node: Register Classes1113643 44200 Node: Old Constraints1140355 44201 Node: Stack and Calling1147506 44202 Node: Frame Layout1148040 44203 Node: Exception Handling1158886 44204 Node: Stack Checking1165264 44205 Node: Frame Registers1169651 44206 Node: Elimination1176257 44207 Node: Stack Arguments1180288 44208 Node: Register Arguments1187091 44209 Node: Scalar Return1202544 44210 Node: Aggregate Return1208090 44211 Node: Caller Saves1211749 44212 Node: Function Entry1212927 44213 Node: Profiling1225542 44214 Node: Tail Calls1227241 44215 Node: Stack Smashing Protection1228608 44216 Node: Varargs1229720 44217 Node: Trampolines1237680 44218 Node: Library Calls1244346 44219 Node: Addressing Modes1249196 44220 Node: Anchored Addresses1265114 44221 Node: Condition Code1267775 44222 Node: Costs1276064 44223 Node: Scheduling1289163 44224 Node: Sections1307724 44225 Node: PIC1322374 44226 Node: Assembler Format1324364 44227 Node: File Framework1325502 44228 Ref: TARGET_HAVE_SWITCHABLE_BSS_SECTIONS1330408 44229 Node: Data Output1333674 44230 Node: Uninitialized Data1341433 44231 Node: Label Output1346504 44232 Node: Initialization1368171 44233 Node: Macros for Initialization1374133 44234 Node: Instruction Output1380585 44235 Node: Dispatch Tables1389579 44236 Node: Exception Region Output1393374 44237 Node: Alignment Output1399134 44238 Node: Debugging Info1403297 44239 Node: All Debuggers1403967 44240 Node: DBX Options1406822 44241 Node: DBX Hooks1412271 44242 Node: File Names and DBX1414197 44243 Node: SDB and DWARF1416308 44244 Node: VMS Debug1420300 44245 Node: Floating Point1420870 44246 Node: Mode Switching1425693 44247 Node: Target Attributes1429619 44248 Node: Emulated TLS1436383 44249 Node: MIPS Coprocessors1439773 44250 Node: PCH Target1441342 44251 Node: C++ ABI1442863 44252 Node: Misc1447482 44253 Ref: TARGET_SHIFT_TRUNCATION_MASK1454853 44254 Node: Host Config1496108 44255 Node: Host Common1497176 44256 Node: Filesystem1499555 44257 Node: Host Misc1503670 44258 Node: Fragments1505809 44259 Node: Target Fragment1507004 44260 Node: Host Fragment1512894 44261 Node: Collect21513134 44262 Node: Header Dirs1515677 44263 Node: Type Information1517100 44264 Node: GTY Options1519391 44265 Node: GGC Roots1530071 44266 Node: Files1530791 44267 Node: Invoking the garbage collector1533541 44268 Node: Plugins1534594 44269 Node: Funding1544959 44270 Node: GNU Project1547446 44271 Node: Copying1548095 44272 Node: GNU Free Documentation License1585626 44273 Node: Contributors1608035 44274 Node: Option Index1644365 44275 Node: Concept Index1644950 44276 44277 End Tag Table 44278
