1 Compiler-RT 2 ================================ 3 4 This directory and its subdirectories contain source code for the compiler 5 support routines. 6 7 Compiler-RT is open source software. You may freely distribute it under the 8 terms of the license agreement found in LICENSE.txt. 9 10 ================================ 11 12 This is a replacement library for libgcc. Each function is contained 13 in its own file. Each function has a corresponding unit test under 14 test/Unit. 15 16 A rudimentary script to test each file is in the file called 17 test/Unit/test. 18 19 Here is the specification for this library: 20 21 http://gcc.gnu.org/onlinedocs/gccint/Libgcc.html#Libgcc 22 23 Here is a synopsis of the contents of this library: 24 25 typedef int si_int; 26 typedef unsigned su_int; 27 28 typedef long long di_int; 29 typedef unsigned long long du_int; 30 31 // Integral bit manipulation 32 33 di_int __ashldi3(di_int a, si_int b); // a << b 34 ti_int __ashlti3(ti_int a, si_int b); // a << b 35 36 di_int __ashrdi3(di_int a, si_int b); // a >> b arithmetic (sign fill) 37 ti_int __ashrti3(ti_int a, si_int b); // a >> b arithmetic (sign fill) 38 di_int __lshrdi3(di_int a, si_int b); // a >> b logical (zero fill) 39 ti_int __lshrti3(ti_int a, si_int b); // a >> b logical (zero fill) 40 41 si_int __clzsi2(si_int a); // count leading zeros 42 si_int __clzdi2(di_int a); // count leading zeros 43 si_int __clzti2(ti_int a); // count leading zeros 44 si_int __ctzsi2(si_int a); // count trailing zeros 45 si_int __ctzdi2(di_int a); // count trailing zeros 46 si_int __ctzti2(ti_int a); // count trailing zeros 47 48 si_int __ffsdi2(di_int a); // find least significant 1 bit 49 si_int __ffsti2(ti_int a); // find least significant 1 bit 50 51 si_int __paritysi2(si_int a); // bit parity 52 si_int __paritydi2(di_int a); // bit parity 53 si_int __parityti2(ti_int a); // bit parity 54 55 si_int __popcountsi2(si_int a); // bit population 56 si_int __popcountdi2(di_int a); // bit population 57 si_int __popcountti2(ti_int a); // bit population 58 59 uint32_t __bswapsi2(uint32_t a); // a byteswapped, arm only 60 uint64_t __bswapdi2(uint64_t a); // a byteswapped, arm only 61 62 // Integral arithmetic 63 64 di_int __negdi2 (di_int a); // -a 65 ti_int __negti2 (ti_int a); // -a 66 di_int __muldi3 (di_int a, di_int b); // a * b 67 ti_int __multi3 (ti_int a, ti_int b); // a * b 68 si_int __divsi3 (si_int a, si_int b); // a / b signed 69 di_int __divdi3 (di_int a, di_int b); // a / b signed 70 ti_int __divti3 (ti_int a, ti_int b); // a / b signed 71 su_int __udivsi3 (su_int n, su_int d); // a / b unsigned 72 du_int __udivdi3 (du_int a, du_int b); // a / b unsigned 73 tu_int __udivti3 (tu_int a, tu_int b); // a / b unsigned 74 si_int __modsi3 (si_int a, si_int b); // a % b signed 75 di_int __moddi3 (di_int a, di_int b); // a % b signed 76 ti_int __modti3 (ti_int a, ti_int b); // a % b signed 77 su_int __umodsi3 (su_int a, su_int b); // a % b unsigned 78 du_int __umoddi3 (du_int a, du_int b); // a % b unsigned 79 tu_int __umodti3 (tu_int a, tu_int b); // a % b unsigned 80 du_int __udivmoddi4(du_int a, du_int b, du_int* rem); // a / b, *rem = a % b 81 tu_int __udivmodti4(tu_int a, tu_int b, tu_int* rem); // a / b, *rem = a % b 82 83 // Integral arithmetic with trapping overflow 84 85 si_int __absvsi2(si_int a); // abs(a) 86 di_int __absvdi2(di_int a); // abs(a) 87 ti_int __absvti2(ti_int a); // abs(a) 88 89 si_int __negvsi2(si_int a); // -a 90 di_int __negvdi2(di_int a); // -a 91 ti_int __negvti2(ti_int a); // -a 92 93 si_int __addvsi3(si_int a, si_int b); // a + b 94 di_int __addvdi3(di_int a, di_int b); // a + b 95 ti_int __addvti3(ti_int a, ti_int b); // a + b 96 97 si_int __subvsi3(si_int a, si_int b); // a - b 98 di_int __subvdi3(di_int a, di_int b); // a - b 99 ti_int __subvti3(ti_int a, ti_int b); // a - b 100 101 si_int __mulvsi3(si_int a, si_int b); // a * b 102 di_int __mulvdi3(di_int a, di_int b); // a * b 103 ti_int __mulvti3(ti_int a, ti_int b); // a * b 104 105 // Integral comparison: a < b -> 0 106 // a == b -> 1 107 // a > b -> 2 108 109 si_int __cmpdi2 (di_int a, di_int b); 110 si_int __cmpti2 (ti_int a, ti_int b); 111 si_int __ucmpdi2(du_int a, du_int b); 112 si_int __ucmpti2(tu_int a, tu_int b); 113 114 // Integral / floating point conversion 115 116 di_int __fixsfdi( float a); 117 di_int __fixdfdi( double a); 118 di_int __fixxfdi(long double a); 119 120 ti_int __fixsfti( float a); 121 ti_int __fixdfti( double a); 122 ti_int __fixxfti(long double a); 123 uint64_t __fixtfdi(long double input); // ppc only, doesn't match documentation 124 125 su_int __fixunssfsi( float a); 126 su_int __fixunsdfsi( double a); 127 su_int __fixunsxfsi(long double a); 128 129 du_int __fixunssfdi( float a); 130 du_int __fixunsdfdi( double a); 131 du_int __fixunsxfdi(long double a); 132 133 tu_int __fixunssfti( float a); 134 tu_int __fixunsdfti( double a); 135 tu_int __fixunsxfti(long double a); 136 uint64_t __fixunstfdi(long double input); // ppc only 137 138 float __floatdisf(di_int a); 139 double __floatdidf(di_int a); 140 long double __floatdixf(di_int a); 141 long double __floatditf(int64_t a); // ppc only 142 143 float __floattisf(ti_int a); 144 double __floattidf(ti_int a); 145 long double __floattixf(ti_int a); 146 147 float __floatundisf(du_int a); 148 double __floatundidf(du_int a); 149 long double __floatundixf(du_int a); 150 long double __floatunditf(uint64_t a); // ppc only 151 152 float __floatuntisf(tu_int a); 153 double __floatuntidf(tu_int a); 154 long double __floatuntixf(tu_int a); 155 156 // Floating point raised to integer power 157 158 float __powisf2( float a, si_int b); // a ^ b 159 double __powidf2( double a, si_int b); // a ^ b 160 long double __powixf2(long double a, si_int b); // a ^ b 161 long double __powitf2(long double a, si_int b); // ppc only, a ^ b 162 163 // Complex arithmetic 164 165 // (a + ib) * (c + id) 166 167 float _Complex __mulsc3( float a, float b, float c, float d); 168 double _Complex __muldc3(double a, double b, double c, double d); 169 long double _Complex __mulxc3(long double a, long double b, 170 long double c, long double d); 171 long double _Complex __multc3(long double a, long double b, 172 long double c, long double d); // ppc only 173 174 // (a + ib) / (c + id) 175 176 float _Complex __divsc3( float a, float b, float c, float d); 177 double _Complex __divdc3(double a, double b, double c, double d); 178 long double _Complex __divxc3(long double a, long double b, 179 long double c, long double d); 180 long double _Complex __divtc3(long double a, long double b, 181 long double c, long double d); // ppc only 182 183 184 // Runtime support 185 186 // __clear_cache() is used to tell process that new instructions have been 187 // written to an address range. Necessary on processors that do not have 188 // a unified instuction and data cache. 189 void __clear_cache(void* start, void* end); 190 191 // __enable_execute_stack() is used with nested functions when a trampoline 192 // function is written onto the stack and that page range needs to be made 193 // executable. 194 void __enable_execute_stack(void* addr); 195 196 // __gcc_personality_v0() is normally only called by the system unwinder. 197 // C code (as opposed to C++) normally does not need a personality function 198 // because there are no catch clauses or destructors to be run. But there 199 // is a C language extension __attribute__((cleanup(func))) which marks local 200 // variables as needing the cleanup function "func" to be run when the 201 // variable goes out of scope. That includes when an exception is thrown, 202 // so a personality handler is needed. 203 _Unwind_Reason_Code __gcc_personality_v0(int version, _Unwind_Action actions, 204 uint64_t exceptionClass, struct _Unwind_Exception* exceptionObject, 205 _Unwind_Context_t context); 206 207 // for use with some implementations of assert() in <assert.h> 208 void __eprintf(const char* format, const char* assertion_expression, 209 const char* line, const char* file); 210 211 212 213 // Power PC specific functions 214 215 // There is no C interface to the saveFP/restFP functions. They are helper 216 // functions called by the prolog and epilog of functions that need to save 217 // a number of non-volatile float point registers. 218 saveFP 219 restFP 220 221 // PowerPC has a standard template for trampoline functions. This function 222 // generates a custom trampoline function with the specific realFunc 223 // and localsPtr values. 224 void __trampoline_setup(uint32_t* trampOnStack, int trampSizeAllocated, 225 const void* realFunc, void* localsPtr); 226 227 // adds two 128-bit double-double precision values ( x + y ) 228 long double __gcc_qadd(long double x, long double y); 229 230 // subtracts two 128-bit double-double precision values ( x - y ) 231 long double __gcc_qsub(long double x, long double y); 232 233 // multiples two 128-bit double-double precision values ( x * y ) 234 long double __gcc_qmul(long double x, long double y); 235 236 // divides two 128-bit double-double precision values ( x / y ) 237 long double __gcc_qdiv(long double a, long double b); 238 239 240 // ARM specific functions 241 242 // There is no C interface to the switch* functions. These helper functions 243 // are only needed by Thumb1 code for efficient switch table generation. 244 switch16 245 switch32 246 switch8 247 switchu8 248 249 // There is no C interface to the *_vfp_d8_d15_regs functions. There are 250 // called in the prolog and epilog of Thumb1 functions. When the C++ ABI use 251 // SJLJ for exceptions, each function with a catch clause or destuctors needs 252 // to save and restore all registers in it prolog and epliog. But there is 253 // no way to access vector and high float registers from thumb1 code, so the 254 // compiler must add call outs to these helper functions in the prolog and 255 // epilog. 256 restore_vfp_d8_d15_regs 257 save_vfp_d8_d15_regs 258 259 260 // Note: long ago ARM processors did not have floating point hardware support. 261 // Floating point was done in software and floating point parameters were 262 // passed in integer registers. When hardware support was added for floating 263 // point, new *vfp functions were added to do the same operations but with 264 // floating point parameters in floating point registers. 265 266 267 // Undocumented functions 268 269 float __addsf3vfp(float a, float b); // Appears to return a + b 270 double __adddf3vfp(double a, double b); // Appears to return a + b 271 float __divsf3vfp(float a, float b); // Appears to return a / b 272 double __divdf3vfp(double a, double b); // Appears to return a / b 273 int __eqsf2vfp(float a, float b); // Appears to return one 274 // iff a == b and neither is NaN. 275 int __eqdf2vfp(double a, double b); // Appears to return one 276 // iff a == b and neither is NaN. 277 double __extendsfdf2vfp(float a); // Appears to convert from 278 // float to double. 279 int __fixdfsivfp(double a); // Appears to convert from 280 // double to int. 281 int __fixsfsivfp(float a); // Appears to convert from 282 // float to int. 283 unsigned int __fixunssfsivfp(float a); // Appears to convert from 284 // float to unsigned int. 285 unsigned int __fixunsdfsivfp(double a); // Appears to convert from 286 // double to unsigned int. 287 double __floatsidfvfp(int a); // Appears to convert from 288 // int to double. 289 float __floatsisfvfp(int a); // Appears to convert from 290 // int to float. 291 double __floatunssidfvfp(unsigned int a); // Appears to convert from 292 // unisgned int to double. 293 float __floatunssisfvfp(unsigned int a); // Appears to convert from 294 // unisgned int to float. 295 int __gedf2vfp(double a, double b); // Appears to return __gedf2 296 // (a >= b) 297 int __gesf2vfp(float a, float b); // Appears to return __gesf2 298 // (a >= b) 299 int __gtdf2vfp(double a, double b); // Appears to return __gtdf2 300 // (a > b) 301 int __gtsf2vfp(float a, float b); // Appears to return __gtsf2 302 // (a > b) 303 int __ledf2vfp(double a, double b); // Appears to return __ledf2 304 // (a <= b) 305 int __lesf2vfp(float a, float b); // Appears to return __lesf2 306 // (a <= b) 307 int __ltdf2vfp(double a, double b); // Appears to return __ltdf2 308 // (a < b) 309 int __ltsf2vfp(float a, float b); // Appears to return __ltsf2 310 // (a < b) 311 double __muldf3vfp(double a, double b); // Appears to return a * b 312 float __mulsf3vfp(float a, float b); // Appears to return a * b 313 int __nedf2vfp(double a, double b); // Appears to return __nedf2 314 // (a != b) 315 double __negdf2vfp(double a); // Appears to return -a 316 float __negsf2vfp(float a); // Appears to return -a 317 float __negsf2vfp(float a); // Appears to return -a 318 double __subdf3vfp(double a, double b); // Appears to return a - b 319 float __subsf3vfp(float a, float b); // Appears to return a - b 320 float __truncdfsf2vfp(double a); // Appears to convert from 321 // double to float. 322 int __unorddf2vfp(double a, double b); // Appears to return __unorddf2 323 int __unordsf2vfp(float a, float b); // Appears to return __unordsf2 324 325 326 Preconditions are listed for each function at the definition when there are any. 327 Any preconditions reflect the specification at 328 http://gcc.gnu.org/onlinedocs/gccint/Libgcc.html#Libgcc. 329 330 Assumptions are listed in "int_lib.h", and in individual files. Where possible 331 assumptions are checked at compile time. 332
