1 /* This file contains the definitions and documentation for the 2 tree codes used in GCC. 3 Copyright (C) 1987, 1988, 1993, 1995, 1997, 1998, 2000, 2001, 2004, 2005, 4 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. 5 6 This file is part of GCC. 7 8 GCC is free software; you can redistribute it and/or modify it under 9 the terms of the GNU General Public License as published by the Free 10 Software Foundation; either version 3, or (at your option) any later 11 version. 12 13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14 WARRANTY; without even the implied warranty of MERCHANTABILITY or 15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16 for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with GCC; see the file COPYING3. If not see 20 <http://www.gnu.org/licenses/>. */ 21 22 23 /* For tcc_references, tcc_expression, tcc_comparison, tcc_unary, 24 tcc_binary, and tcc_statement nodes, which use struct tree_exp, the 25 4th element is the number of argument slots to allocate. This 26 determines the size of the tree node object. Other nodes use 27 different structures, and the size is determined by the tree_union 28 member structure; the 4th element should be zero. Languages that 29 define language-specific tcc_exceptional or tcc_constant codes must 30 define the tree_size langhook to say how big they are. 31 32 These tree codes have been sorted so that the macros in tree.h that 33 check for various tree codes are optimized into range checks. This 34 gives a measurable performance improvement. When adding a new 35 code, consider its placement in relation to the other codes. */ 36 37 /* Any erroneous construct is parsed into a node of this type. 38 This type of node is accepted without complaint in all contexts 39 by later parsing activities, to avoid multiple error messages 40 for one error. 41 No fields in these nodes are used except the TREE_CODE. */ 42 DEFTREECODE (ERROR_MARK, "error_mark", tcc_exceptional, 0) 43 44 /* Used to represent a name (such as, in the DECL_NAME of a decl node). 45 Internally it looks like a STRING_CST node. 46 There is only one IDENTIFIER_NODE ever made for any particular name. 47 Use `get_identifier' to get it (or create it, the first time). */ 48 DEFTREECODE (IDENTIFIER_NODE, "identifier_node", tcc_exceptional, 0) 49 50 /* Has the TREE_VALUE and TREE_PURPOSE fields. */ 51 /* These nodes are made into lists by chaining through the 52 TREE_CHAIN field. The elements of the list live in the 53 TREE_VALUE fields, while TREE_PURPOSE fields are occasionally 54 used as well to get the effect of Lisp association lists. */ 55 DEFTREECODE (TREE_LIST, "tree_list", tcc_exceptional, 0) 56 57 /* These nodes contain an array of tree nodes. */ 58 DEFTREECODE (TREE_VEC, "tree_vec", tcc_exceptional, 0) 59 60 /* A symbol binding block. These are arranged in a tree, 61 where the BLOCK_SUBBLOCKS field contains a chain of subblocks 62 chained through the BLOCK_CHAIN field. 63 BLOCK_SUPERCONTEXT points to the parent block. 64 For a block which represents the outermost scope of a function, it 65 points to the FUNCTION_DECL node. 66 BLOCK_VARS points to a chain of decl nodes. 67 BLOCK_CHAIN points to the next BLOCK at the same level. 68 BLOCK_ABSTRACT_ORIGIN points to the original (abstract) tree node which 69 this block is an instance of, or else is NULL to indicate that this 70 block is not an instance of anything else. When non-NULL, the value 71 could either point to another BLOCK node or it could point to a 72 FUNCTION_DECL node (e.g. in the case of a block representing the 73 outermost scope of a particular inlining of a function). 74 BLOCK_ABSTRACT is nonzero if the block represents an abstract 75 instance of a block (i.e. one which is nested within an abstract 76 instance of an inline function). 77 TREE_ASM_WRITTEN is nonzero if the block was actually referenced 78 in the generated assembly. */ 79 DEFTREECODE (BLOCK, "block", tcc_exceptional, 0) 80 81 /* Each data type is represented by a tree node whose code is one of 83 the following: */ 84 /* Each node that represents a data type has a component TYPE_SIZE 85 containing a tree that is an expression for the size in bits. 86 The TYPE_MODE contains the machine mode for values of this type. 87 The TYPE_POINTER_TO field contains a type for a pointer to this type, 88 or zero if no such has been created yet. 89 The TYPE_NEXT_VARIANT field is used to chain together types 90 that are variants made by type modifiers such as "const" and "volatile". 91 The TYPE_MAIN_VARIANT field, in any member of such a chain, 92 points to the start of the chain. 93 The TYPE_NAME field contains info on the name used in the program 94 for this type (for GDB symbol table output). It is either a 95 TYPE_DECL node, for types that are typedefs, or an IDENTIFIER_NODE 96 in the case of structs, unions or enums that are known with a tag, 97 or zero for types that have no special name. 98 The TYPE_CONTEXT for any sort of type which could have a name or 99 which could have named members (e.g. tagged types in C/C++) will 100 point to the node which represents the scope of the given type, or 101 will be NULL_TREE if the type has "file scope". For most types, this 102 will point to a BLOCK node or a FUNCTION_DECL node, but it could also 103 point to a FUNCTION_TYPE node (for types whose scope is limited to the 104 formal parameter list of some function type specification) or it 105 could point to a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE node 106 (for C++ "member" types). 107 For non-tagged-types, TYPE_CONTEXT need not be set to anything in 108 particular, since any type which is of some type category (e.g. 109 an array type or a function type) which cannot either have a name 110 itself or have named members doesn't really have a "scope" per se. 111 The TREE_CHAIN field is used as a forward-references to names for 112 ENUMERAL_TYPE, RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE nodes; 113 see below. */ 114 115 /* The ordering of the following codes is optimized for the checking 116 macros in tree.h. Changing the order will degrade the speed of the 117 compiler. OFFSET_TYPE, ENUMERAL_TYPE, BOOLEAN_TYPE, INTEGER_TYPE, 118 REAL_TYPE, POINTER_TYPE. */ 119 120 /* An offset is a pointer relative to an object. 121 The TREE_TYPE field is the type of the object at the offset. 122 The TYPE_OFFSET_BASETYPE points to the node for the type of object 123 that the offset is relative to. */ 124 DEFTREECODE (OFFSET_TYPE, "offset_type", tcc_type, 0) 125 126 /* C enums. The type node looks just like an INTEGER_TYPE node. 127 The symbols for the values of the enum type are defined by 128 CONST_DECL nodes, but the type does not point to them; 129 however, the TYPE_VALUES is a list in which each element's TREE_PURPOSE 130 is a name and the TREE_VALUE is the value (an INTEGER_CST node). */ 131 /* A forward reference `enum foo' when no enum named foo is defined yet 132 has zero (a null pointer) in its TYPE_SIZE. The tag name is in 133 the TYPE_NAME field. If the type is later defined, the normal 134 fields are filled in. 135 RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE forward refs are 136 treated similarly. */ 137 DEFTREECODE (ENUMERAL_TYPE, "enumeral_type", tcc_type, 0) 138 139 /* Boolean type (true or false are the only values). Looks like an 140 INTEGRAL_TYPE. */ 141 DEFTREECODE (BOOLEAN_TYPE, "boolean_type", tcc_type, 0) 142 143 /* Integer types in all languages, including char in C. 144 Also used for sub-ranges of other discrete types. 145 Has components TYPE_MIN_VALUE, TYPE_MAX_VALUE (expressions, inclusive) 146 and TYPE_PRECISION (number of bits used by this type). 147 In the case of a subrange type in Pascal, the TREE_TYPE 148 of this will point at the supertype (another INTEGER_TYPE, 149 or an ENUMERAL_TYPE or BOOLEAN_TYPE). 150 Otherwise, the TREE_TYPE is zero. */ 151 DEFTREECODE (INTEGER_TYPE, "integer_type", tcc_type, 0) 152 153 /* C's float and double. Different floating types are distinguished 154 by machine mode and by the TYPE_SIZE and the TYPE_PRECISION. */ 155 DEFTREECODE (REAL_TYPE, "real_type", tcc_type, 0) 156 157 /* The ordering of the following codes is optimized for the checking 158 macros in tree.h. Changing the order will degrade the speed of the 159 compiler. POINTER_TYPE, REFERENCE_TYPE. Note that this range 160 overlaps the previous range of ordered types. */ 161 162 /* All pointer-to-x types have code POINTER_TYPE. 163 The TREE_TYPE points to the node for the type pointed to. */ 164 DEFTREECODE (POINTER_TYPE, "pointer_type", tcc_type, 0) 165 166 /* A reference is like a pointer except that it is coerced 167 automatically to the value it points to. Used in C++. */ 168 DEFTREECODE (REFERENCE_TYPE, "reference_type", tcc_type, 0) 169 170 /* The C++ decltype(nullptr) type. */ 171 DEFTREECODE (NULLPTR_TYPE, "nullptr_type", tcc_type, 0) 172 173 /* _Fract and _Accum types in Embedded-C. Different fixed-point types 174 are distinguished by machine mode and by the TYPE_SIZE and the 175 TYPE_PRECISION. */ 176 DEFTREECODE (FIXED_POINT_TYPE, "fixed_point_type", tcc_type, 0) 177 178 /* The ordering of the following codes is optimized for the checking 179 macros in tree.h. Changing the order will degrade the speed of the 180 compiler. COMPLEX_TYPE, VECTOR_TYPE, ARRAY_TYPE. */ 181 182 /* Complex number types. The TREE_TYPE field is the data type 183 of the real and imaginary parts. It must be of scalar 184 arithmetic type, not including pointer type. */ 185 DEFTREECODE (COMPLEX_TYPE, "complex_type", tcc_type, 0) 186 187 /* Vector types. The TREE_TYPE field is the data type of the vector 188 elements. The TYPE_PRECISION field is the number of subparts of 189 the vector. */ 190 DEFTREECODE (VECTOR_TYPE, "vector_type", tcc_type, 0) 191 192 /* The ordering of the following codes is optimized for the checking 193 macros in tree.h. Changing the order will degrade the speed of the 194 compiler. ARRAY_TYPE, RECORD_TYPE, UNION_TYPE, QUAL_UNION_TYPE. 195 Note that this range overlaps the previous range. */ 196 197 /* Types of arrays. Special fields: 198 TREE_TYPE Type of an array element. 199 TYPE_DOMAIN Type to index by. 200 Its range of values specifies the array length. 201 The field TYPE_POINTER_TO (TREE_TYPE (array_type)) is always nonzero 202 and holds the type to coerce a value of that array type to in C. 203 TYPE_STRING_FLAG indicates a string (in contrast to an array of chars) 204 in languages (such as Chill) that make a distinction. */ 205 /* Array types in C or Pascal */ 206 DEFTREECODE (ARRAY_TYPE, "array_type", tcc_type, 0) 207 208 /* Struct in C, or record in Pascal. */ 209 /* Special fields: 210 TYPE_FIELDS chain of FIELD_DECLs for the fields of the struct, 211 and VAR_DECLs, TYPE_DECLs and CONST_DECLs for record-scope variables, 212 types and enumerators. 213 A few may need to be added for Pascal. */ 214 /* See the comment above, before ENUMERAL_TYPE, for how 215 forward references to struct tags are handled in C. */ 216 DEFTREECODE (RECORD_TYPE, "record_type", tcc_type, 0) 217 218 /* Union in C. Like a struct, except that the offsets of the fields 219 will all be zero. */ 220 /* See the comment above, before ENUMERAL_TYPE, for how 221 forward references to union tags are handled in C. */ 222 DEFTREECODE (UNION_TYPE, "union_type", tcc_type, 0) /* C union type */ 223 224 /* Similar to UNION_TYPE, except that the expressions in DECL_QUALIFIER 225 in each FIELD_DECL determine what the union contains. The first 226 field whose DECL_QUALIFIER expression is true is deemed to occupy 227 the union. */ 228 DEFTREECODE (QUAL_UNION_TYPE, "qual_union_type", tcc_type, 0) 229 230 /* The ordering of the following codes is optimized for the checking 231 macros in tree.h. Changing the order will degrade the speed of the 232 compiler. VOID_TYPE, FUNCTION_TYPE, METHOD_TYPE. */ 233 234 /* The void type in C */ 235 DEFTREECODE (VOID_TYPE, "void_type", tcc_type, 0) 236 237 /* Type of functions. Special fields: 238 TREE_TYPE type of value returned. 239 TYPE_ARG_TYPES list of types of arguments expected. 240 this list is made of TREE_LIST nodes. 241 Types of "Procedures" in languages where they are different from functions 242 have code FUNCTION_TYPE also, but then TREE_TYPE is zero or void type. */ 243 DEFTREECODE (FUNCTION_TYPE, "function_type", tcc_type, 0) 244 245 /* METHOD_TYPE is the type of a function which takes an extra first 246 argument for "self", which is not present in the declared argument list. 247 The TREE_TYPE is the return type of the method. The TYPE_METHOD_BASETYPE 248 is the type of "self". TYPE_ARG_TYPES is the real argument list, which 249 includes the hidden argument for "self". */ 250 DEFTREECODE (METHOD_TYPE, "method_type", tcc_type, 0) 251 252 /* This is a language-specific kind of type. 253 Its meaning is defined by the language front end. 254 layout_type does not know how to lay this out, 255 so the front-end must do so manually. */ 256 DEFTREECODE (LANG_TYPE, "lang_type", tcc_type, 0) 257 258 /* Expressions */ 260 261 /* First, the constants. */ 262 263 /* Contents are in TREE_INT_CST_LOW and TREE_INT_CST_HIGH fields, 264 32 bits each, giving us a 64 bit constant capability. INTEGER_CST 265 nodes can be shared, and therefore should be considered read only. 266 They should be copied, before setting a flag such as TREE_OVERFLOW. 267 If an INTEGER_CST has TREE_OVERFLOW already set, it is known to be unique. 268 INTEGER_CST nodes are created for the integral types, for pointer 269 types and for vector and float types in some circumstances. */ 270 DEFTREECODE (INTEGER_CST, "integer_cst", tcc_constant, 0) 271 272 /* Contents are in TREE_REAL_CST field. */ 273 DEFTREECODE (REAL_CST, "real_cst", tcc_constant, 0) 274 275 /* Contents are in TREE_FIXED_CST field. */ 276 DEFTREECODE (FIXED_CST, "fixed_cst", tcc_constant, 0) 277 278 /* Contents are in TREE_REALPART and TREE_IMAGPART fields, 279 whose contents are other constant nodes. */ 280 DEFTREECODE (COMPLEX_CST, "complex_cst", tcc_constant, 0) 281 282 /* Contents are in TREE_VECTOR_CST_ELTS field. */ 283 DEFTREECODE (VECTOR_CST, "vector_cst", tcc_constant, 0) 284 285 /* Contents are TREE_STRING_LENGTH and the actual contents of the string. */ 286 DEFTREECODE (STRING_CST, "string_cst", tcc_constant, 0) 287 288 /* Declarations. All references to names are represented as ..._DECL 289 nodes. The decls in one binding context are chained through the 290 TREE_CHAIN field. Each DECL has a DECL_NAME field which contains 291 an IDENTIFIER_NODE. (Some decls, most often labels, may have zero 292 as the DECL_NAME). DECL_CONTEXT points to the node representing 293 the context in which this declaration has its scope. For 294 FIELD_DECLs, this is the RECORD_TYPE, UNION_TYPE, or 295 QUAL_UNION_TYPE node that the field is a member of. For VAR_DECL, 296 PARM_DECL, FUNCTION_DECL, LABEL_DECL, and CONST_DECL nodes, this 297 points to either the FUNCTION_DECL for the containing function, the 298 RECORD_TYPE or UNION_TYPE for the containing type, or NULL_TREE or 299 a TRANSLATION_UNIT_DECL if the given decl has "file scope". 300 DECL_ABSTRACT_ORIGIN, if non-NULL, points to the original (abstract) 301 ..._DECL node of which this decl is an (inlined or template expanded) 302 instance. 303 The TREE_TYPE field holds the data type of the object, when relevant. 304 LABEL_DECLs have no data type. For TYPE_DECL, the TREE_TYPE field 305 contents are the type whose name is being declared. 306 The DECL_ALIGN, DECL_SIZE, 307 and DECL_MODE fields exist in decl nodes just as in type nodes. 308 They are unused in LABEL_DECL, TYPE_DECL and CONST_DECL nodes. 309 310 DECL_FIELD_BIT_OFFSET holds an integer number of bits offset for 311 the location. DECL_VOFFSET holds an expression for a variable 312 offset; it is to be multiplied by DECL_VOFFSET_UNIT (an integer). 313 These fields are relevant only in FIELD_DECLs and PARM_DECLs. 314 315 DECL_INITIAL holds the value to initialize a variable to, 316 or the value of a constant. For a function, it holds the body 317 (a node of type BLOCK representing the function's binding contour 318 and whose body contains the function's statements.) For a LABEL_DECL 319 in C, it is a flag, nonzero if the label's definition has been seen. 320 321 PARM_DECLs use a special field: 322 DECL_ARG_TYPE is the type in which the argument is actually 323 passed, which may be different from its type within the function. 324 325 FUNCTION_DECLs use four special fields: 326 DECL_ARGUMENTS holds a chain of PARM_DECL nodes for the arguments. 327 DECL_RESULT holds a RESULT_DECL node for the value of a function. 328 The DECL_RTL field is 0 for a function that returns no value. 329 (C functions returning void have zero here.) 330 The TREE_TYPE field is the type in which the result is actually 331 returned. This is usually the same as the return type of the 332 FUNCTION_DECL, but it may be a wider integer type because of 333 promotion. 334 DECL_FUNCTION_CODE is a code number that is nonzero for 335 built-in functions. Its value is an enum built_in_function 336 that says which built-in function it is. 337 338 DECL_SOURCE_FILE holds a filename string and DECL_SOURCE_LINE 339 holds a line number. In some cases these can be the location of 340 a reference, if no definition has been seen. 341 342 DECL_ABSTRACT is nonzero if the decl represents an abstract instance 343 of a decl (i.e. one which is nested within an abstract instance of a 344 inline function. */ 345 346 DEFTREECODE (FUNCTION_DECL, "function_decl", tcc_declaration, 0) 347 DEFTREECODE (LABEL_DECL, "label_decl", tcc_declaration, 0) 348 /* The ordering of the following codes is optimized for the checking 349 macros in tree.h. Changing the order will degrade the speed of the 350 compiler. FIELD_DECL, VAR_DECL, CONST_DECL, PARM_DECL, 351 TYPE_DECL. */ 352 DEFTREECODE (FIELD_DECL, "field_decl", tcc_declaration, 0) 353 DEFTREECODE (VAR_DECL, "var_decl", tcc_declaration, 0) 354 DEFTREECODE (CONST_DECL, "const_decl", tcc_declaration, 0) 355 DEFTREECODE (PARM_DECL, "parm_decl", tcc_declaration, 0) 356 DEFTREECODE (TYPE_DECL, "type_decl", tcc_declaration, 0) 357 DEFTREECODE (RESULT_DECL, "result_decl", tcc_declaration, 0) 358 359 /* A "declaration" of a debug temporary. It should only appear in 360 DEBUG stmts. */ 361 DEFTREECODE (DEBUG_EXPR_DECL, "debug_expr_decl", tcc_declaration, 0) 362 363 /* A namespace declaration. Namespaces appear in DECL_CONTEXT of other 364 _DECLs, providing a hierarchy of names. */ 365 DEFTREECODE (NAMESPACE_DECL, "namespace_decl", tcc_declaration, 0) 366 367 /* A declaration import. 368 The C++ FE uses this to represent a using-directive; eg: 369 "using namespace foo". 370 But it could be used to represent any declaration import construct. 371 Whenever a declaration import appears in a lexical block, the BLOCK node 372 representing that lexical block in GIMPLE will contain an IMPORTED_DECL 373 node, linked via BLOCK_VARS accessor of the said BLOCK. 374 For a given NODE which code is IMPORTED_DECL, 375 IMPORTED_DECL_ASSOCIATED_DECL (NODE) accesses the imported declaration. */ 376 DEFTREECODE (IMPORTED_DECL, "imported_decl", tcc_declaration, 0) 377 378 /* A translation unit. This is not technically a declaration, since it 379 can't be looked up, but it's close enough. */ 380 DEFTREECODE (TRANSLATION_UNIT_DECL, "translation_unit_decl",\ 381 tcc_declaration, 0) 382 383 /* References to storage. */ 385 386 /* The ordering of the following codes is optimized for the classification 387 in handled_component_p. Keep them in a consecutive group. */ 388 389 /* Value is structure or union component. 390 Operand 0 is the structure or union (an expression). 391 Operand 1 is the field (a node of type FIELD_DECL). 392 Operand 2, if present, is the value of DECL_FIELD_OFFSET, measured 393 in units of DECL_OFFSET_ALIGN / BITS_PER_UNIT. */ 394 DEFTREECODE (COMPONENT_REF, "component_ref", tcc_reference, 3) 395 396 /* Reference to a group of bits within an object. Similar to COMPONENT_REF 397 except the position is given explicitly rather than via a FIELD_DECL. 398 Operand 0 is the structure or union expression; 399 operand 1 is a tree giving the constant number of bits being referenced; 400 operand 2 is a tree giving the constant position of the first referenced bit. 401 The result type width has to match the number of bits referenced. 402 If the result type is integral, its signedness specifies how it is extended 403 to its mode width. */ 404 DEFTREECODE (BIT_FIELD_REF, "bit_field_ref", tcc_reference, 3) 405 406 /* Used only on an operand of complex type, these return 407 a value of the corresponding component type. */ 408 DEFTREECODE (REALPART_EXPR, "realpart_expr", tcc_reference, 1) 409 DEFTREECODE (IMAGPART_EXPR, "imagpart_expr", tcc_reference, 1) 410 411 /* Array indexing. 412 Operand 0 is the array; operand 1 is a (single) array index. 413 Operand 2, if present, is a copy of TYPE_MIN_VALUE of the index. 414 Operand 3, if present, is the element size, measured in units of 415 the alignment of the element type. */ 416 DEFTREECODE (ARRAY_REF, "array_ref", tcc_reference, 4) 417 418 /* Likewise, except that the result is a range ("slice") of the array. The 419 starting index of the resulting array is taken from operand 1 and the size 420 of the range is taken from the type of the expression. */ 421 DEFTREECODE (ARRAY_RANGE_REF, "array_range_ref", tcc_reference, 4) 422 423 /* C unary `*' or Pascal `^'. One operand, an expression for a pointer. */ 424 DEFTREECODE (INDIRECT_REF, "indirect_ref", tcc_reference, 1) 425 426 /* Used to represent lookup in a virtual method table which is dependent on 427 the runtime type of an object. Operands are: 428 OBJ_TYPE_REF_EXPR: An expression that evaluates the value to use. 429 OBJ_TYPE_REF_OBJECT: Is the object on whose behalf the lookup is 430 being performed. Through this the optimizers may be able to statically 431 determine the dynamic type of the object. 432 OBJ_TYPE_REF_TOKEN: An integer index to the virtual method table. */ 433 DEFTREECODE (OBJ_TYPE_REF, "obj_type_ref", tcc_expression, 3) 434 435 /* Constructor: return an aggregate value made from specified components. 436 In C, this is used only for structure and array initializers. 437 The operand is a sequence of component values made out of a VEC of 438 struct constructor_elt. 439 440 For ARRAY_TYPE: 441 The field INDEX of each constructor_elt is the corresponding index. 442 If the index is a RANGE_EXPR, it is a short-hand for many nodes, 443 one for each index in the range. (If the corresponding field VALUE 444 has side-effects, they are evaluated once for each element. Wrap the 445 value in a SAVE_EXPR if you want to evaluate side effects only once.) 446 447 For RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE: 448 The field INDEX of each node is a FIELD_DECL. */ 449 DEFTREECODE (CONSTRUCTOR, "constructor", tcc_exceptional, 0) 450 451 /* The expression types are mostly straightforward, with the fourth argument 452 of DEFTREECODE saying how many operands there are. 453 Unless otherwise specified, the operands are expressions and the 454 types of all the operands and the expression must all be the same. */ 455 456 /* Contains two expressions to compute, one followed by the other. 457 the first value is ignored. The second one's value is used. The 458 type of the first expression need not agree with the other types. */ 459 DEFTREECODE (COMPOUND_EXPR, "compound_expr", tcc_expression, 2) 460 461 /* Assignment expression. Operand 0 is the what to set; 1, the new value. */ 462 DEFTREECODE (MODIFY_EXPR, "modify_expr", tcc_expression, 2) 463 464 /* Initialization expression. Operand 0 is the variable to initialize; 465 Operand 1 is the initializer. This differs from MODIFY_EXPR in that any 466 reference to the referent of operand 0 within operand 1 is undefined. */ 467 DEFTREECODE (INIT_EXPR, "init_expr", tcc_expression, 2) 468 469 /* For TARGET_EXPR, operand 0 is the target of an initialization, 470 operand 1 is the initializer for the target, which may be void 471 if simply expanding it initializes the target. 472 operand 2 is the cleanup for this node, if any. 473 operand 3 is the saved initializer after this node has been 474 expanded once; this is so we can re-expand the tree later. */ 475 DEFTREECODE (TARGET_EXPR, "target_expr", tcc_expression, 4) 476 477 /* Conditional expression ( ... ? ... : ... in C). 478 Operand 0 is the condition. 479 Operand 1 is the then-value. 480 Operand 2 is the else-value. 481 Operand 0 may be of any type. 482 Operand 1 must have the same type as the entire expression, unless 483 it unconditionally throws an exception, in which case it should 484 have VOID_TYPE. The same constraints apply to operand 2. The 485 condition in operand 0 must be of integral type. 486 487 In cfg gimple, if you do not have a selection expression, operands 488 1 and 2 are NULL. The operands are then taken from the cfg edges. */ 489 DEFTREECODE (COND_EXPR, "cond_expr", tcc_expression, 3) 490 491 /* Vector conditional expression. It is like COND_EXPR, but with 492 vector operands. 493 494 A = VEC_COND_EXPR ( X < Y, B, C) 495 496 means 497 498 for (i=0; i<N; i++) 499 A[i] = X[i] < Y[i] ? B[i] : C[i]; 500 */ 501 DEFTREECODE (VEC_COND_EXPR, "vec_cond_expr", tcc_expression, 3) 502 503 /* Declare local variables, including making RTL and allocating space. 504 BIND_EXPR_VARS is a chain of VAR_DECL nodes for the variables. 505 BIND_EXPR_BODY is the body, the expression to be computed using 506 the variables. The value of operand 1 becomes that of the BIND_EXPR. 507 BIND_EXPR_BLOCK is the BLOCK that corresponds to these bindings 508 for debugging purposes. If this BIND_EXPR is actually expanded, 509 that sets the TREE_USED flag in the BLOCK. 510 511 The BIND_EXPR is not responsible for informing parsers 512 about these variables. If the body is coming from the input file, 513 then the code that creates the BIND_EXPR is also responsible for 514 informing the parser of the variables. 515 516 If the BIND_EXPR is ever expanded, its TREE_USED flag is set. 517 This tells the code for debugging symbol tables not to ignore the BIND_EXPR. 518 If the BIND_EXPR should be output for debugging but will not be expanded, 519 set the TREE_USED flag by hand. 520 521 In order for the BIND_EXPR to be known at all, the code that creates it 522 must also install it as a subblock in the tree of BLOCK 523 nodes for the function. */ 524 DEFTREECODE (BIND_EXPR, "bind_expr", tcc_expression, 3) 525 526 /* Function call. CALL_EXPRs are represented by variably-sized expression 527 nodes. There are at least three fixed operands. Operand 0 is an 528 INTEGER_CST node containing the total operand count, the number of 529 arguments plus 3. Operand 1 is the function, while operand 2 is 530 is static chain argument, or NULL. The remaining operands are the 531 arguments to the call. */ 532 DEFTREECODE (CALL_EXPR, "call_expr", tcc_vl_exp, 3) 533 534 /* Specify a value to compute along with its corresponding cleanup. 535 Operand 0 is the cleanup expression. 536 The cleanup is executed by the first enclosing CLEANUP_POINT_EXPR, 537 which must exist. This differs from TRY_CATCH_EXPR in that operand 1 538 is always evaluated when cleanups are run. */ 539 DEFTREECODE (WITH_CLEANUP_EXPR, "with_cleanup_expr", tcc_expression, 1) 540 541 /* Specify a cleanup point. 542 Operand 0 is an expression that may have cleanups. If it does, those 543 cleanups are executed after the expression is expanded. 544 545 Note that if the expression is a reference to storage, it is forced out 546 of memory before the cleanups are run. This is necessary to handle 547 cases where the cleanups modify the storage referenced; in the 548 expression 't.i', if 't' is a struct with an integer member 'i' and a 549 cleanup which modifies 'i', the value of the expression depends on 550 whether the cleanup is run before or after 't.i' is evaluated. When 551 expand_expr is run on 't.i', it returns a MEM. This is not good enough; 552 the value of 't.i' must be forced out of memory. 553 554 As a consequence, the operand of a CLEANUP_POINT_EXPR must not have 555 BLKmode, because it will not be forced out of memory. */ 556 DEFTREECODE (CLEANUP_POINT_EXPR, "cleanup_point_expr", tcc_expression, 1) 557 558 /* The following code is used in languages that have types where some 559 field in an object of the type contains a value that is used in the 560 computation of another field's offset or size and/or the size of the 561 type. The positions and/or sizes of fields can vary from object to 562 object of the same type or even for one and the same object within 563 its scope. 564 565 Record types with discriminants in Ada or schema types in Pascal are 566 examples of such types. This mechanism is also used to create "fat 567 pointers" for unconstrained array types in Ada; the fat pointer is a 568 structure one of whose fields is a pointer to the actual array type 569 and the other field is a pointer to a template, which is a structure 570 containing the bounds of the array. The bounds in the type pointed 571 to by the first field in the fat pointer refer to the values in the 572 template. 573 574 When you wish to construct such a type you need "self-references" 575 that allow you to reference the object having this type from the 576 TYPE node, i.e. without having a variable instantiating this type. 577 578 Such a "self-references" is done using a PLACEHOLDER_EXPR. This is 579 a node that will later be replaced with the object being referenced. 580 Its type is that of the object and selects which object to use from 581 a chain of references (see below). No other slots are used in the 582 PLACEHOLDER_EXPR. 583 584 For example, if your type FOO is a RECORD_TYPE with a field BAR, 585 and you need the value of <variable>.BAR to calculate TYPE_SIZE 586 (FOO), just substitute <variable> above with a PLACEHOLDER_EXPR 587 whose TREE_TYPE is FOO. Then construct your COMPONENT_REF with 588 the PLACEHOLDER_EXPR as the first operand (which has the correct 589 type). Later, when the size is needed in the program, the back-end 590 will find this PLACEHOLDER_EXPR and generate code to calculate the 591 actual size at run-time. In the following, we describe how this 592 calculation is done. 593 594 When we wish to evaluate a size or offset, we check whether it contains a 595 PLACEHOLDER_EXPR. If it does, we call substitute_placeholder_in_expr 596 passing both that tree and an expression within which the object may be 597 found. The latter expression is the object itself in the simple case of 598 an Ada record with discriminant, but it can be the array in the case of an 599 unconstrained array. 600 601 In the latter case, we need the fat pointer, because the bounds of 602 the array can only be accessed from it. However, we rely here on the 603 fact that the expression for the array contains the dereference of 604 the fat pointer that obtained the array pointer. */ 605 606 /* Denotes a record to later be substituted before evaluating this expression. 607 The type of this expression is used to find the record to replace it. */ 608 DEFTREECODE (PLACEHOLDER_EXPR, "placeholder_expr", tcc_exceptional, 0) 609 610 /* Simple arithmetic. */ 611 DEFTREECODE (PLUS_EXPR, "plus_expr", tcc_binary, 2) 612 DEFTREECODE (MINUS_EXPR, "minus_expr", tcc_binary, 2) 613 DEFTREECODE (MULT_EXPR, "mult_expr", tcc_binary, 2) 614 615 /* Pointer addition. The first operand is always a pointer and the 616 second operand is an integer of type sizetype. */ 617 DEFTREECODE (POINTER_PLUS_EXPR, "pointer_plus_expr", tcc_binary, 2) 618 619 /* Division for integer result that rounds the quotient toward zero. */ 620 DEFTREECODE (TRUNC_DIV_EXPR, "trunc_div_expr", tcc_binary, 2) 621 622 /* Division for integer result that rounds the quotient toward infinity. */ 623 DEFTREECODE (CEIL_DIV_EXPR, "ceil_div_expr", tcc_binary, 2) 624 625 /* Division for integer result that rounds toward minus infinity. */ 626 DEFTREECODE (FLOOR_DIV_EXPR, "floor_div_expr", tcc_binary, 2) 627 628 /* Division for integer result that rounds toward nearest integer. */ 629 DEFTREECODE (ROUND_DIV_EXPR, "round_div_expr", tcc_binary, 2) 630 631 /* Four kinds of remainder that go with the four kinds of division. */ 632 DEFTREECODE (TRUNC_MOD_EXPR, "trunc_mod_expr", tcc_binary, 2) 633 DEFTREECODE (CEIL_MOD_EXPR, "ceil_mod_expr", tcc_binary, 2) 634 DEFTREECODE (FLOOR_MOD_EXPR, "floor_mod_expr", tcc_binary, 2) 635 DEFTREECODE (ROUND_MOD_EXPR, "round_mod_expr", tcc_binary, 2) 636 637 /* Division for real result. */ 638 DEFTREECODE (RDIV_EXPR, "rdiv_expr", tcc_binary, 2) 639 640 /* Division which is not supposed to need rounding. 641 Used for pointer subtraction in C. */ 642 DEFTREECODE (EXACT_DIV_EXPR, "exact_div_expr", tcc_binary, 2) 643 644 /* Conversion of real to fixed point by truncation. */ 645 DEFTREECODE (FIX_TRUNC_EXPR, "fix_trunc_expr", tcc_unary, 1) 646 647 /* Conversion of an integer to a real. */ 648 DEFTREECODE (FLOAT_EXPR, "float_expr", tcc_unary, 1) 649 650 /* Unary negation. */ 651 DEFTREECODE (NEGATE_EXPR, "negate_expr", tcc_unary, 1) 652 653 /* Minimum and maximum values. When used with floating point, if both 654 operands are zeros, or if either operand is NaN, then it is unspecified 655 which of the two operands is returned as the result. */ 656 DEFTREECODE (MIN_EXPR, "min_expr", tcc_binary, 2) 657 DEFTREECODE (MAX_EXPR, "max_expr", tcc_binary, 2) 658 659 /* Represents the absolute value of the operand. 660 661 An ABS_EXPR must have either an INTEGER_TYPE or a REAL_TYPE. The 662 operand of the ABS_EXPR must have the same type. */ 663 DEFTREECODE (ABS_EXPR, "abs_expr", tcc_unary, 1) 664 665 /* Shift operations for shift and rotate. 666 Shift means logical shift if done on an 667 unsigned type, arithmetic shift if done on a signed type. 668 The second operand is the number of bits to 669 shift by; it need not be the same type as the first operand and result. 670 Note that the result is undefined if the second operand is larger 671 than or equal to the first operand's type size. 672 673 The first operand of a shift can have either an integer or a 674 (non-integer) fixed-point type. We follow the ISO/IEC TR 18037:2004 675 semantics for the latter. 676 677 Rotates are defined for integer types only. */ 678 DEFTREECODE (LSHIFT_EXPR, "lshift_expr", tcc_binary, 2) 679 DEFTREECODE (RSHIFT_EXPR, "rshift_expr", tcc_binary, 2) 680 DEFTREECODE (LROTATE_EXPR, "lrotate_expr", tcc_binary, 2) 681 DEFTREECODE (RROTATE_EXPR, "rrotate_expr", tcc_binary, 2) 682 683 /* Bitwise operations. Operands have same mode as result. */ 684 DEFTREECODE (BIT_IOR_EXPR, "bit_ior_expr", tcc_binary, 2) 685 DEFTREECODE (BIT_XOR_EXPR, "bit_xor_expr", tcc_binary, 2) 686 DEFTREECODE (BIT_AND_EXPR, "bit_and_expr", tcc_binary, 2) 687 DEFTREECODE (BIT_NOT_EXPR, "bit_not_expr", tcc_unary, 1) 688 689 /* ANDIF and ORIF allow the second operand not to be computed if the 690 value of the expression is determined from the first operand. AND, 691 OR, and XOR always compute the second operand whether its value is 692 needed or not (for side effects). The operand may have 693 BOOLEAN_TYPE or INTEGER_TYPE. In either case, the argument will be 694 either zero or one. For example, a TRUTH_NOT_EXPR will never have 695 an INTEGER_TYPE VAR_DECL as its argument; instead, a NE_EXPR will be 696 used to compare the VAR_DECL to zero, thereby obtaining a node with 697 value zero or one. */ 698 DEFTREECODE (TRUTH_ANDIF_EXPR, "truth_andif_expr", tcc_expression, 2) 699 DEFTREECODE (TRUTH_ORIF_EXPR, "truth_orif_expr", tcc_expression, 2) 700 DEFTREECODE (TRUTH_AND_EXPR, "truth_and_expr", tcc_expression, 2) 701 DEFTREECODE (TRUTH_OR_EXPR, "truth_or_expr", tcc_expression, 2) 702 DEFTREECODE (TRUTH_XOR_EXPR, "truth_xor_expr", tcc_expression, 2) 703 DEFTREECODE (TRUTH_NOT_EXPR, "truth_not_expr", tcc_expression, 1) 704 705 /* Relational operators. 706 `EQ_EXPR' and `NE_EXPR' are allowed for any types. 707 The others are allowed only for integer (or pointer or enumeral) 708 or real types. 709 In all cases the operands will have the same type, 710 and the value is always the type used by the language for booleans. */ 711 DEFTREECODE (LT_EXPR, "lt_expr", tcc_comparison, 2) 712 DEFTREECODE (LE_EXPR, "le_expr", tcc_comparison, 2) 713 DEFTREECODE (GT_EXPR, "gt_expr", tcc_comparison, 2) 714 DEFTREECODE (GE_EXPR, "ge_expr", tcc_comparison, 2) 715 DEFTREECODE (EQ_EXPR, "eq_expr", tcc_comparison, 2) 716 DEFTREECODE (NE_EXPR, "ne_expr", tcc_comparison, 2) 717 718 /* Additional relational operators for floating point unordered. */ 719 DEFTREECODE (UNORDERED_EXPR, "unordered_expr", tcc_comparison, 2) 720 DEFTREECODE (ORDERED_EXPR, "ordered_expr", tcc_comparison, 2) 721 722 /* These are equivalent to unordered or ... */ 723 DEFTREECODE (UNLT_EXPR, "unlt_expr", tcc_comparison, 2) 724 DEFTREECODE (UNLE_EXPR, "unle_expr", tcc_comparison, 2) 725 DEFTREECODE (UNGT_EXPR, "ungt_expr", tcc_comparison, 2) 726 DEFTREECODE (UNGE_EXPR, "unge_expr", tcc_comparison, 2) 727 DEFTREECODE (UNEQ_EXPR, "uneq_expr", tcc_comparison, 2) 728 729 /* This is the reverse of uneq_expr. */ 730 DEFTREECODE (LTGT_EXPR, "ltgt_expr", tcc_comparison, 2) 731 732 DEFTREECODE (RANGE_EXPR, "range_expr", tcc_binary, 2) 733 734 /* Represents a re-association barrier for floating point expressions 735 like explicit parenthesis in fortran. */ 736 DEFTREECODE (PAREN_EXPR, "paren_expr", tcc_unary, 1) 737 738 /* Represents a conversion of type of a value. 739 All conversions, including implicit ones, must be 740 represented by CONVERT_EXPR or NOP_EXPR nodes. */ 741 DEFTREECODE (CONVERT_EXPR, "convert_expr", tcc_unary, 1) 742 743 /* Conversion of a pointer value to a pointer to a different 744 address space. */ 745 DEFTREECODE (ADDR_SPACE_CONVERT_EXPR, "addr_space_convert_expr", tcc_unary, 1) 746 747 /* Conversion of a fixed-point value to an integer, a real, or a fixed-point 748 value. Or conversion of a fixed-point value from an integer, a real, or 749 a fixed-point value. */ 750 DEFTREECODE (FIXED_CONVERT_EXPR, "fixed_convert_expr", tcc_unary, 1) 751 752 /* Represents a conversion expected to require no code to be generated. */ 753 DEFTREECODE (NOP_EXPR, "nop_expr", tcc_unary, 1) 754 755 /* Value is same as argument, but guaranteed not an lvalue. */ 756 DEFTREECODE (NON_LVALUE_EXPR, "non_lvalue_expr", tcc_unary, 1) 757 758 /* Represents viewing something of one type as being of a second type. 759 This corresponds to an "Unchecked Conversion" in Ada and roughly to 760 the idiom *(type2 *)&X in C. The only operand is the value to be 761 viewed as being of another type. It is undefined if the type of the 762 input and of the expression have different sizes. 763 764 This code may also be used within the LHS of a MODIFY_EXPR, in which 765 case no actual data motion may occur. TREE_ADDRESSABLE will be set in 766 this case and GCC must abort if it could not do the operation without 767 generating insns. */ 768 DEFTREECODE (VIEW_CONVERT_EXPR, "view_convert_expr", tcc_reference, 1) 769 770 /* A COMPOUND_LITERAL_EXPR represents a literal that is placed in a DECL. The 771 COMPOUND_LITERAL_EXPR_DECL_EXPR is the a DECL_EXPR containing the decl 772 for the anonymous object represented by the COMPOUND_LITERAL; 773 the DECL_INITIAL of that decl is the CONSTRUCTOR that initializes 774 the compound literal. */ 775 DEFTREECODE (COMPOUND_LITERAL_EXPR, "compound_literal_expr", tcc_expression, 1) 776 777 /* Represents something we computed once and will use multiple times. 778 First operand is that expression. After it is evaluated once, it 779 will be replaced by the temporary variable that holds the value. */ 780 DEFTREECODE (SAVE_EXPR, "save_expr", tcc_expression, 1) 781 782 /* & in C. Value is the address at which the operand's value resides. 783 Operand may have any mode. Result mode is Pmode. */ 784 DEFTREECODE (ADDR_EXPR, "addr_expr", tcc_expression, 1) 785 786 /* Operand0 is a function constant; result is part N of a function 787 descriptor of type ptr_mode. */ 788 DEFTREECODE (FDESC_EXPR, "fdesc_expr", tcc_expression, 2) 789 790 /* Given two real or integer operands of the same type, 791 returns a complex value of the corresponding complex type. */ 792 DEFTREECODE (COMPLEX_EXPR, "complex_expr", tcc_binary, 2) 793 794 /* Complex conjugate of operand. Used only on complex types. */ 795 DEFTREECODE (CONJ_EXPR, "conj_expr", tcc_unary, 1) 796 797 /* Nodes for ++ and -- in C. 798 The second arg is how much to increment or decrement by. 799 For a pointer, it would be the size of the object pointed to. */ 800 DEFTREECODE (PREDECREMENT_EXPR, "predecrement_expr", tcc_expression, 2) 801 DEFTREECODE (PREINCREMENT_EXPR, "preincrement_expr", tcc_expression, 2) 802 DEFTREECODE (POSTDECREMENT_EXPR, "postdecrement_expr", tcc_expression, 2) 803 DEFTREECODE (POSTINCREMENT_EXPR, "postincrement_expr", tcc_expression, 2) 804 805 /* Used to implement `va_arg'. */ 806 DEFTREECODE (VA_ARG_EXPR, "va_arg_expr", tcc_expression, 1) 807 808 /* Evaluate operand 1. If and only if an exception is thrown during 809 the evaluation of operand 1, evaluate operand 2. 810 811 This differs from TRY_FINALLY_EXPR in that operand 2 is not evaluated 812 on a normal or jump exit, only on an exception. */ 813 DEFTREECODE (TRY_CATCH_EXPR, "try_catch_expr", tcc_statement, 2) 814 815 /* Evaluate the first operand. 816 The second operand is a cleanup expression which is evaluated 817 on any exit (normal, exception, or jump out) from this expression. */ 818 DEFTREECODE (TRY_FINALLY_EXPR, "try_finally", tcc_statement, 2) 819 820 /* These types of expressions have no useful value, 822 and always have side effects. */ 823 824 /* Used to represent a local declaration. The operand is DECL_EXPR_DECL. */ 825 DEFTREECODE (DECL_EXPR, "decl_expr", tcc_statement, 1) 826 827 /* A label definition, encapsulated as a statement. 828 Operand 0 is the LABEL_DECL node for the label that appears here. 829 The type should be void and the value should be ignored. */ 830 DEFTREECODE (LABEL_EXPR, "label_expr", tcc_statement, 1) 831 832 /* GOTO. Operand 0 is a LABEL_DECL node or an expression. 833 The type should be void and the value should be ignored. */ 834 DEFTREECODE (GOTO_EXPR, "goto_expr", tcc_statement, 1) 835 836 /* RETURN. Evaluates operand 0, then returns from the current function. 837 Presumably that operand is an assignment that stores into the 838 RESULT_DECL that hold the value to be returned. 839 The operand may be null. 840 The type should be void and the value should be ignored. */ 841 DEFTREECODE (RETURN_EXPR, "return_expr", tcc_statement, 1) 842 843 /* Exit the inner most loop conditionally. Operand 0 is the condition. 844 The type should be void and the value should be ignored. */ 845 DEFTREECODE (EXIT_EXPR, "exit_expr", tcc_statement, 1) 846 847 /* A loop. Operand 0 is the body of the loop. 848 It must contain an EXIT_EXPR or is an infinite loop. 849 The type should be void and the value should be ignored. */ 850 DEFTREECODE (LOOP_EXPR, "loop_expr", tcc_statement, 1) 851 852 /* Switch expression. 853 854 TREE_TYPE is the original type of the condition, before any 855 language required type conversions. It may be NULL, in which case 856 the original type and final types are assumed to be the same. 857 858 Operand 0 is the expression used to perform the branch, 859 Operand 1 is the body of the switch, which probably contains 860 CASE_LABEL_EXPRs. It may also be NULL, in which case operand 2 861 must not be NULL. 862 Operand 2 is either NULL_TREE or a TREE_VEC of the CASE_LABEL_EXPRs 863 of all the cases. */ 864 DEFTREECODE (SWITCH_EXPR, "switch_expr", tcc_statement, 3) 865 866 /* Used to represent a case label. The operands are CASE_LOW and 867 CASE_HIGH, respectively. If CASE_LOW is NULL_TREE, the label is a 868 'default' label. If CASE_HIGH is NULL_TREE, the label is a normal case 869 label. CASE_LABEL is the corresponding LABEL_DECL. */ 870 DEFTREECODE (CASE_LABEL_EXPR, "case_label_expr", tcc_statement, 3) 871 872 /* Used to represent an inline assembly statement. ASM_STRING returns a 873 STRING_CST for the instruction (e.g., "mov x, y"). ASM_OUTPUTS, 874 ASM_INPUTS, and ASM_CLOBBERS represent the outputs, inputs, and clobbers 875 for the statement. ASM_LABELS, if present, indicates various destinations 876 for the asm; labels cannot be combined with outputs. */ 877 DEFTREECODE (ASM_EXPR, "asm_expr", tcc_statement, 5) 878 879 /* Variable references for SSA analysis. New SSA names are created every 880 time a variable is assigned a new value. The SSA builder uses SSA_NAME 881 nodes to implement SSA versioning. */ 882 DEFTREECODE (SSA_NAME, "ssa_name", tcc_exceptional, 0) 883 884 /* Used to represent a typed exception handler. CATCH_TYPES is the type (or 885 list of types) handled, and CATCH_BODY is the code for the handler. */ 886 DEFTREECODE (CATCH_EXPR, "catch_expr", tcc_statement, 2) 887 888 /* Used to represent an exception specification. EH_FILTER_TYPES is a list 889 of allowed types, and EH_FILTER_FAILURE is an expression to evaluate on 890 failure. EH_FILTER_MUST_NOT_THROW controls which range type to use when 891 expanding. */ 892 DEFTREECODE (EH_FILTER_EXPR, "eh_filter_expr", tcc_statement, 2) 893 894 /* Node used for describing a property that is known at compile 895 time. */ 896 DEFTREECODE (SCEV_KNOWN, "scev_known", tcc_expression, 0) 897 898 /* Node used for describing a property that is not known at compile 899 time. */ 900 DEFTREECODE (SCEV_NOT_KNOWN, "scev_not_known", tcc_expression, 0) 901 902 /* Polynomial chains of recurrences. 903 Under the form: cr = {CHREC_LEFT (cr), +, CHREC_RIGHT (cr)}. */ 904 DEFTREECODE (POLYNOMIAL_CHREC, "polynomial_chrec", tcc_expression, 3) 905 906 /* Used to chain children of container statements together. 907 Use the interface in tree-iterator.h to access this node. */ 908 DEFTREECODE (STATEMENT_LIST, "statement_list", tcc_exceptional, 0) 909 910 /* Predicate assertion. Artificial expression generated by the optimizers 911 to keep track of predicate values. This expression may only appear on 912 the RHS of assignments. 913 914 Given X = ASSERT_EXPR <Y, EXPR>, the optimizers can infer 915 two things: 916 917 1- X is a copy of Y. 918 2- EXPR is a conditional expression and is known to be true. 919 920 Valid and to be expected forms of conditional expressions are 921 valid GIMPLE conditional expressions (as defined by is_gimple_condexpr) 922 and conditional expressions with the first operand being a 923 PLUS_EXPR with a variable possibly wrapped in a NOP_EXPR first 924 operand and an integer constant second operand. 925 926 The type of the expression is the same as Y. */ 927 DEFTREECODE (ASSERT_EXPR, "assert_expr", tcc_expression, 2) 928 929 /* Base class information. Holds information about a class as a 930 baseclass of itself or another class. */ 931 DEFTREECODE (TREE_BINFO, "tree_binfo", tcc_exceptional, 0) 932 933 /* Records the size for an expression of variable size type. This is 934 for use in contexts in which we are accessing the entire object, 935 such as for a function call, or block copy. 936 Operand 0 is the real expression. 937 Operand 1 is the size of the type in the expression. */ 938 DEFTREECODE (WITH_SIZE_EXPR, "with_size_expr", tcc_expression, 2) 939 940 /* Extract elements from two input vectors Operand 0 and Operand 1 941 size VS, according to the offset OFF defined by Operand 2 as 942 follows: 943 If OFF > 0, the last VS - OFF elements of vector OP0 are concatenated to 944 the first OFF elements of the vector OP1. 945 If OFF == 0, then the returned vector is OP1. 946 On different targets OFF may take different forms; It can be an address, in 947 which case its low log2(VS)-1 bits define the offset, or it can be a mask 948 generated by the builtin targetm.vectorize.mask_for_load_builtin_decl. */ 949 DEFTREECODE (REALIGN_LOAD_EXPR, "realign_load", tcc_expression, 3) 950 951 /* Low-level memory addressing. Operands are BASE (address of static or 952 global variable or register), OFFSET (integer constant), 953 INDEX (register), STEP (integer constant), INDEX2 (register), 954 The corresponding address is BASE + STEP * INDEX + INDEX2 + OFFSET. 955 Only variations and values valid on the target are allowed. 956 957 The type of STEP, INDEX and INDEX2 is sizetype. 958 959 The type of BASE is a pointer type. If BASE is not an address of 960 a static or global variable INDEX2 will be NULL. 961 962 The type of OFFSET is a pointer type and determines TBAA the same as 963 the constant offset operand in MEM_REF. */ 964 965 DEFTREECODE (TARGET_MEM_REF, "target_mem_ref", tcc_reference, 5) 966 967 /* Memory addressing. Operands are a pointer and a tree constant integer 968 byte offset of the pointer type that when dereferenced yields the 969 type of the base object the pointer points into and which is used for 970 TBAA purposes. 971 The type of the MEM_REF is the type the bytes at the memory location 972 are interpreted as. 973 MEM_REF <p, c> is equivalent to ((typeof(c))p)->x... where x... is a 974 chain of component references offsetting p by c. */ 975 DEFTREECODE (MEM_REF, "mem_ref", tcc_reference, 2) 976 977 /* The ordering of the codes between OMP_PARALLEL and OMP_CRITICAL is 978 exposed to TREE_RANGE_CHECK. */ 979 /* OpenMP - #pragma omp parallel [clause1 ... clauseN] 980 Operand 0: OMP_PARALLEL_BODY: Code to be executed by all threads. 981 Operand 1: OMP_PARALLEL_CLAUSES: List of clauses. */ 982 983 DEFTREECODE (OMP_PARALLEL, "omp_parallel", tcc_statement, 2) 984 985 /* OpenMP - #pragma omp task [clause1 ... clauseN] 986 Operand 0: OMP_TASK_BODY: Code to be executed by all threads. 987 Operand 1: OMP_TASK_CLAUSES: List of clauses. */ 988 989 DEFTREECODE (OMP_TASK, "omp_task", tcc_statement, 2) 990 991 /* OpenMP - #pragma omp for [clause1 ... clauseN] 992 Operand 0: OMP_FOR_BODY: Loop body. 993 Operand 1: OMP_FOR_CLAUSES: List of clauses. 994 Operand 2: OMP_FOR_INIT: Initialization code of the form 995 VAR = N1. 996 Operand 3: OMP_FOR_COND: Loop conditional expression of the form 997 VAR { <, >, <=, >= } N2. 998 Operand 4: OMP_FOR_INCR: Loop index increment of the form 999 VAR { +=, -= } INCR. 1000 Operand 5: OMP_FOR_PRE_BODY: Filled by the gimplifier with things 1001 from INIT, COND, and INCR that are technically part of the 1002 OMP_FOR structured block, but are evaluated before the loop 1003 body begins. 1004 1005 VAR must be an integer or pointer variable, which is implicitly thread 1006 private. N1, N2 and INCR are required to be loop invariant integer 1007 expressions that are evaluated without any synchronization. 1008 The evaluation order, frequency of evaluation and side-effects are 1009 unspecified by the standard. */ 1010 DEFTREECODE (OMP_FOR, "omp_for", tcc_statement, 6) 1011 1012 /* OpenMP - #pragma omp sections [clause1 ... clauseN] 1013 Operand 0: OMP_SECTIONS_BODY: Sections body. 1014 Operand 1: OMP_SECTIONS_CLAUSES: List of clauses. */ 1015 DEFTREECODE (OMP_SECTIONS, "omp_sections", tcc_statement, 2) 1016 1017 /* OpenMP - #pragma omp single 1018 Operand 0: OMP_SINGLE_BODY: Single section body. 1019 Operand 1: OMP_SINGLE_CLAUSES: List of clauses. */ 1020 DEFTREECODE (OMP_SINGLE, "omp_single", tcc_statement, 2) 1021 1022 /* OpenMP - #pragma omp section 1023 Operand 0: OMP_SECTION_BODY: Section body. */ 1024 DEFTREECODE (OMP_SECTION, "omp_section", tcc_statement, 1) 1025 1026 /* OpenMP - #pragma omp master 1027 Operand 0: OMP_MASTER_BODY: Master section body. */ 1028 DEFTREECODE (OMP_MASTER, "omp_master", tcc_statement, 1) 1029 1030 /* OpenMP - #pragma omp ordered 1031 Operand 0: OMP_ORDERED_BODY: Master section body. */ 1032 DEFTREECODE (OMP_ORDERED, "omp_ordered", tcc_statement, 1) 1033 1034 /* OpenMP - #pragma omp critical [name] 1035 Operand 0: OMP_CRITICAL_BODY: Critical section body. 1036 Operand 1: OMP_CRITICAL_NAME: Identifier for critical section. */ 1037 DEFTREECODE (OMP_CRITICAL, "omp_critical", tcc_statement, 2) 1038 1039 /* OpenMP - #pragma omp atomic 1040 Operand 0: The address at which the atomic operation is to be performed. 1041 This address should be stabilized with save_expr. 1042 Operand 1: The expression to evaluate. When the old value of the object 1043 at the address is used in the expression, it should appear as if 1044 build_fold_indirect_ref of the address. */ 1045 DEFTREECODE (OMP_ATOMIC, "omp_atomic", tcc_statement, 2) 1046 1047 /* OpenMP clauses. */ 1048 DEFTREECODE (OMP_CLAUSE, "omp_clause", tcc_exceptional, 0) 1049 1050 /* Reduction operations. 1051 Operations that take a vector of elements and "reduce" it to a scalar 1052 result (e.g. summing the elements of the vector, finding the minimum over 1053 the vector elements, etc). 1054 Operand 0 is a vector; the first element in the vector has the result. 1055 Operand 1 is a vector. */ 1056 DEFTREECODE (REDUC_MAX_EXPR, "reduc_max_expr", tcc_unary, 1) 1057 DEFTREECODE (REDUC_MIN_EXPR, "reduc_min_expr", tcc_unary, 1) 1058 DEFTREECODE (REDUC_PLUS_EXPR, "reduc_plus_expr", tcc_unary, 1) 1059 1060 /* Widening dot-product. 1061 The first two arguments are of type t1. 1062 The third argument and the result are of type t2, such that t2 is at least 1063 twice the size of t1. DOT_PROD_EXPR(arg1,arg2,arg3) is equivalent to: 1064 tmp = WIDEN_MULT_EXPR(arg1, arg2); 1065 arg3 = PLUS_EXPR (tmp, arg3); 1066 or: 1067 tmp = WIDEN_MULT_EXPR(arg1, arg2); 1068 arg3 = WIDEN_SUM_EXPR (tmp, arg3); */ 1069 DEFTREECODE (DOT_PROD_EXPR, "dot_prod_expr", tcc_expression, 3) 1070 1071 /* Widening summation. 1072 The first argument is of type t1. 1073 The second argument is of type t2, such that t2 is at least twice 1074 the size of t1. The type of the entire expression is also t2. 1075 WIDEN_SUM_EXPR is equivalent to first widening (promoting) 1076 the first argument from type t1 to type t2, and then summing it 1077 with the second argument. */ 1078 DEFTREECODE (WIDEN_SUM_EXPR, "widen_sum_expr", tcc_binary, 2) 1079 1080 /* Widening multiplication. 1081 The two arguments are of type t1. 1082 The result is of type t2, such that t2 is at least twice 1083 the size of t1. WIDEN_MULT_EXPR is equivalent to first widening (promoting) 1084 the arguments from type t1 to type t2, and then multiplying them. */ 1085 DEFTREECODE (WIDEN_MULT_EXPR, "widen_mult_expr", tcc_binary, 2) 1086 1087 /* Widening multiply-accumulate. 1088 The first two arguments are of type t1. 1089 The third argument and the result are of type t2, such as t2 is at least 1090 twice the size of t1. t1 and t2 must be integral or fixed-point types. 1091 The expression is equivalent to a WIDEN_MULT_EXPR operation 1092 of the first two operands followed by an add or subtract of the third 1093 operand. */ 1094 DEFTREECODE (WIDEN_MULT_PLUS_EXPR, "widen_mult_plus_expr", tcc_expression, 3) 1095 /* This is like the above, except in the final expression the multiply result 1096 is subtracted from t3. */ 1097 DEFTREECODE (WIDEN_MULT_MINUS_EXPR, "widen_mult_minus_expr", tcc_expression, 3) 1098 1099 /* Fused multiply-add. 1100 All operands and the result are of the same type. No intermediate 1101 rounding is performed after multiplying operand one with operand two 1102 before adding operand three. */ 1103 DEFTREECODE (FMA_EXPR, "fma_expr", tcc_expression, 3) 1104 1105 /* Whole vector left/right shift in bits. 1106 Operand 0 is a vector to be shifted. 1107 Operand 1 is an integer shift amount in bits. */ 1108 DEFTREECODE (VEC_LSHIFT_EXPR, "vec_lshift_expr", tcc_binary, 2) 1109 DEFTREECODE (VEC_RSHIFT_EXPR, "vec_rshift_expr", tcc_binary, 2) 1110 1111 /* Widening vector multiplication. 1113 The two operands are vectors with N elements of size S. Multiplying the 1114 elements of the two vectors will result in N products of size 2*S. 1115 VEC_WIDEN_MULT_HI_EXPR computes the N/2 high products. 1116 VEC_WIDEN_MULT_LO_EXPR computes the N/2 low products. */ 1117 DEFTREECODE (VEC_WIDEN_MULT_HI_EXPR, "widen_mult_hi_expr", tcc_binary, 2) 1118 DEFTREECODE (VEC_WIDEN_MULT_LO_EXPR, "widen_mult_lo_expr", tcc_binary, 2) 1119 1120 /* Unpack (extract and promote/widen) the high/low elements of the input 1121 vector into the output vector. The input vector has twice as many 1122 elements as the output vector, that are half the size of the elements 1123 of the output vector. This is used to support type promotion. */ 1124 DEFTREECODE (VEC_UNPACK_HI_EXPR, "vec_unpack_hi_expr", tcc_unary, 1) 1125 DEFTREECODE (VEC_UNPACK_LO_EXPR, "vec_unpack_lo_expr", tcc_unary, 1) 1126 1127 /* Unpack (extract) the high/low elements of the input vector, convert 1128 fixed point values to floating point and widen elements into the 1129 output vector. The input vector has twice as many elements as the output 1130 vector, that are half the size of the elements of the output vector. */ 1131 DEFTREECODE (VEC_UNPACK_FLOAT_HI_EXPR, "vec_unpack_float_hi_expr", tcc_unary, 1) 1132 DEFTREECODE (VEC_UNPACK_FLOAT_LO_EXPR, "vec_unpack_float_lo_expr", tcc_unary, 1) 1133 1134 /* Pack (demote/narrow and merge) the elements of the two input vectors 1135 into the output vector using truncation/saturation. 1136 The elements of the input vectors are twice the size of the elements of the 1137 output vector. This is used to support type demotion. */ 1138 DEFTREECODE (VEC_PACK_TRUNC_EXPR, "vec_pack_trunc_expr", tcc_binary, 2) 1139 DEFTREECODE (VEC_PACK_SAT_EXPR, "vec_pack_sat_expr", tcc_binary, 2) 1140 1141 /* Convert floating point values of the two input vectors to integer 1142 and pack (narrow and merge) the elements into the output vector. The 1143 elements of the input vector are twice the size of the elements of 1144 the output vector. */ 1145 DEFTREECODE (VEC_PACK_FIX_TRUNC_EXPR, "vec_pack_fix_trunc_expr", tcc_binary, 2) 1146 1147 /* Extract even/odd fields from vectors. */ 1148 DEFTREECODE (VEC_EXTRACT_EVEN_EXPR, "vec_extracteven_expr", tcc_binary, 2) 1149 DEFTREECODE (VEC_EXTRACT_ODD_EXPR, "vec_extractodd_expr", tcc_binary, 2) 1150 1151 /* Merge input vectors interleaving their fields. */ 1152 DEFTREECODE (VEC_INTERLEAVE_HIGH_EXPR, "vec_interleavehigh_expr", tcc_binary, 2) 1153 DEFTREECODE (VEC_INTERLEAVE_LOW_EXPR, "vec_interleavelow_expr", tcc_binary, 2) 1154 1155 /* PREDICT_EXPR. Specify hint for branch prediction. The 1156 PREDICT_EXPR_PREDICTOR specify predictor and PREDICT_EXPR_OUTCOME the 1157 outcome (0 for not taken and 1 for taken). Once the profile is guessed 1158 all conditional branches leading to execution paths executing the 1159 PREDICT_EXPR will get predicted by the specified predictor. */ 1160 DEFTREECODE (PREDICT_EXPR, "predict_expr", tcc_expression, 1) 1161 1162 /* OPTIMIZATION_NODE. Node to store the optimization options. */ 1163 DEFTREECODE (OPTIMIZATION_NODE, "optimization_node", tcc_exceptional, 0) 1164 1165 /* TARGET_OPTION_NODE. Node to store the target specific options. */ 1166 DEFTREECODE (TARGET_OPTION_NODE, "target_option_node", tcc_exceptional, 0) 1167 1168 /* 1169 Local variables: 1170 mode:c 1171 End: 1172 */ 1173
