README.txt revision 225736
1204076SpjdCompiler-RT 2204076Spjd================================ 3219351Spjd 4204076SpjdThis directory and its subdirectories contain source code for the compiler 5204076Spjdsupport routines. 6204076Spjd 7204076SpjdCompiler-RT is open source software. You may freely distribute it under the 8204076Spjdterms of the license agreement found in LICENSE.txt. 9204076Spjd 10204076Spjd================================ 11204076Spjd 12204076SpjdThis is a replacement library for libgcc. Each function is contained 13204076Spjdin its own file. Each function has a corresponding unit test under 14204076Spjdtest/Unit. 15204076Spjd 16204076SpjdA rudimentary script to test each file is in the file called 17204076Spjdtest/Unit/test. 18204076Spjd 19204076SpjdHere is the specification for this library: 20204076Spjd 21204076Spjdhttp://gcc.gnu.org/onlinedocs/gccint/Libgcc.html#Libgcc 22204076Spjd 23204076SpjdHere is a synopsis of the contents of this library: 24204076Spjd 25204076Spjdtypedef int si_int; 26204076Spjdtypedef unsigned su_int; 27204076Spjd 28204076Spjdtypedef long long di_int; 29204076Spjdtypedef unsigned long long du_int; 30204076Spjd 31204076Spjd// Integral bit manipulation 32204076Spjd 33204076Spjddi_int __ashldi3(di_int a, si_int b); // a << b 34204076Spjdti_int __ashlti3(ti_int a, si_int b); // a << b 35204076Spjd 36204076Spjddi_int __ashrdi3(di_int a, si_int b); // a >> b arithmetic (sign fill) 37204076Spjdti_int __ashrti3(ti_int a, si_int b); // a >> b arithmetic (sign fill) 38204076Spjddi_int __lshrdi3(di_int a, si_int b); // a >> b logical (zero fill) 39204076Spjdti_int __lshrti3(ti_int a, si_int b); // a >> b logical (zero fill) 40204076Spjd 41204076Spjdsi_int __clzsi2(si_int a); // count leading zeros 42204076Spjdsi_int __clzdi2(di_int a); // count leading zeros 43204076Spjdsi_int __clzti2(ti_int a); // count leading zeros 44204076Spjdsi_int __ctzsi2(si_int a); // count trailing zeros 45219351Spjdsi_int __ctzdi2(di_int a); // count trailing zeros 46219351Spjdsi_int __ctzti2(ti_int a); // count trailing zeros 47219351Spjd 48219354Spjdsi_int __ffsdi2(di_int a); // find least significant 1 bit 49204076Spjdsi_int __ffsti2(ti_int a); // find least significant 1 bit 50204076Spjd 51204076Spjdsi_int __paritysi2(si_int a); // bit parity 52204076Spjdsi_int __paritydi2(di_int a); // bit parity 53204076Spjdsi_int __parityti2(ti_int a); // bit parity 54204076Spjd 55204076Spjdsi_int __popcountsi2(si_int a); // bit population 56204076Spjdsi_int __popcountdi2(di_int a); // bit population 57204076Spjdsi_int __popcountti2(ti_int a); // bit population 58212033Spjd 59212033Spjduint32_t __bswapsi2(uint32_t a); // a byteswapped, arm only 60212033Spjduint64_t __bswapdi2(uint64_t a); // a byteswapped, arm only 61212033Spjd 62204076Spjd// Integral arithmetic 63204076Spjd 64204076Spjddi_int __negdi2 (di_int a); // -a 65204076Spjdti_int __negti2 (ti_int a); // -a 66204076Spjddi_int __muldi3 (di_int a, di_int b); // a * b 67204076Spjdti_int __multi3 (ti_int a, ti_int b); // a * b 68204076Spjdsi_int __divsi3 (si_int a, si_int b); // a / b signed 69204076Spjddi_int __divdi3 (di_int a, di_int b); // a / b signed 70219354Spjdti_int __divti3 (ti_int a, ti_int b); // a / b signed 71221078Strocinysu_int __udivsi3 (su_int n, su_int d); // a / b unsigned 72204076Spjddu_int __udivdi3 (du_int a, du_int b); // a / b unsigned 73221078Strocinytu_int __udivti3 (tu_int a, tu_int b); // a / b unsigned 74204076Spjdsi_int __modsi3 (si_int a, si_int b); // a % b signed 75204076Spjddi_int __moddi3 (di_int a, di_int b); // a % b signed 76204076Spjdti_int __modti3 (ti_int a, ti_int b); // a % b signed 77204076Spjdsu_int __umodsi3 (su_int a, su_int b); // a % b unsigned 78204076Spjddu_int __umoddi3 (du_int a, du_int b); // a % b unsigned 79204076Spjdtu_int __umodti3 (tu_int a, tu_int b); // a % b unsigned 80204076Spjddu_int __udivmoddi4(du_int a, du_int b, du_int* rem); // a / b, *rem = a % b unsigned 81204076Spjdtu_int __udivmodti4(tu_int a, tu_int b, tu_int* rem); // a / b, *rem = a % b unsigned 82212033Spjdsu_int __udivmodsi4(su_int a, su_int b, su_int* rem); // a / b, *rem = a % b unsigned 83204076Spjdsi_int __divmodsi4(si_int a, si_int b, si_int* rem); // a / b, *rem = a % b signed 84204076Spjd 85204076Spjd 86204076Spjd 87204076Spjd// Integral arithmetic with trapping overflow 88204076Spjd 89204076Spjdsi_int __absvsi2(si_int a); // abs(a) 90204076Spjddi_int __absvdi2(di_int a); // abs(a) 91204076Spjdti_int __absvti2(ti_int a); // abs(a) 92204076Spjd 93204076Spjdsi_int __negvsi2(si_int a); // -a 94204076Spjddi_int __negvdi2(di_int a); // -a 95204076Spjdti_int __negvti2(ti_int a); // -a 96204076Spjd 97204076Spjdsi_int __addvsi3(si_int a, si_int b); // a + b 98204076Spjddi_int __addvdi3(di_int a, di_int b); // a + b 99204076Spjdti_int __addvti3(ti_int a, ti_int b); // a + b 100204076Spjd 101219351Spjdsi_int __subvsi3(si_int a, si_int b); // a - b 102204076Spjddi_int __subvdi3(di_int a, di_int b); // a - b 103204076Spjdti_int __subvti3(ti_int a, ti_int b); // a - b 104204076Spjd 105204076Spjdsi_int __mulvsi3(si_int a, si_int b); // a * b 106204076Spjddi_int __mulvdi3(di_int a, di_int b); // a * b 107204076Spjdti_int __mulvti3(ti_int a, ti_int b); // a * b 108204076Spjd 109204076Spjd// Integral comparison: a < b -> 0 110204076Spjd// a == b -> 1 111204076Spjd// a > b -> 2 112204076Spjd 113204076Spjdsi_int __cmpdi2 (di_int a, di_int b); 114204076Spjdsi_int __cmpti2 (ti_int a, ti_int b); 115246922Spjdsi_int __ucmpdi2(du_int a, du_int b); 116204076Spjdsi_int __ucmpti2(tu_int a, tu_int b); 117229945Spjd 118204076Spjd// Integral / floating point conversion 119204076Spjd 120204076Spjddi_int __fixsfdi( float a); 121229945Spjddi_int __fixdfdi( double a); 122204076Spjddi_int __fixxfdi(long double a); 123229945Spjd 124204076Spjdti_int __fixsfti( float a); 125204076Spjdti_int __fixdfti( double a); 126204076Spjdti_int __fixxfti(long double a); 127204076Spjduint64_t __fixtfdi(long double input); // ppc only, doesn't match documentation 128204076Spjd 129204076Spjdsu_int __fixunssfsi( float a); 130204076Spjdsu_int __fixunsdfsi( double a); 131204076Spjdsu_int __fixunsxfsi(long double a); 132204076Spjd 133204076Spjddu_int __fixunssfdi( float a); 134212033Spjddu_int __fixunsdfdi( double a); 135204076Spjddu_int __fixunsxfdi(long double a); 136204076Spjd 137204076Spjdtu_int __fixunssfti( float a); 138204076Spjdtu_int __fixunsdfti( double a); 139204076Spjdtu_int __fixunsxfti(long double a); 140204076Spjduint64_t __fixunstfdi(long double input); // ppc only 141204076Spjd 142204076Spjdfloat __floatdisf(di_int a); 143204076Spjddouble __floatdidf(di_int a); 144229945Spjdlong double __floatdixf(di_int a); 145204076Spjdlong double __floatditf(int64_t a); // ppc only 146204076Spjd 147246922Spjdfloat __floattisf(ti_int a); 148204076Spjddouble __floattidf(ti_int a); 149204076Spjdlong double __floattixf(ti_int a); 150204076Spjd 151204076Spjdfloat __floatundisf(du_int a); 152204076Spjddouble __floatundidf(du_int a); 153204076Spjdlong double __floatundixf(du_int a); 154204076Spjdlong double __floatunditf(uint64_t a); // ppc only 155204076Spjd 156204076Spjdfloat __floatuntisf(tu_int a); 157229945Spjddouble __floatuntidf(tu_int a); 158204076Spjdlong double __floatuntixf(tu_int a); 159204076Spjd 160225787Spjd// Floating point raised to integer power 161229945Spjd 162204076Spjdfloat __powisf2( float a, si_int b); // a ^ b 163204076Spjddouble __powidf2( double a, si_int b); // a ^ b 164204076Spjdlong double __powixf2(long double a, si_int b); // a ^ b 165204076Spjdlong double __powitf2(long double a, si_int b); // ppc only, a ^ b 166204076Spjd 167204076Spjd// Complex arithmetic 168204076Spjd 169204076Spjd// (a + ib) * (c + id) 170209175Spjd 171204076Spjd float _Complex __mulsc3( float a, float b, float c, float d); 172204076Spjd double _Complex __muldc3(double a, double b, double c, double d); 173204076Spjdlong double _Complex __mulxc3(long double a, long double b, 174204076Spjd long double c, long double d); 175204076Spjdlong double _Complex __multc3(long double a, long double b, 176212033Spjd long double c, long double d); // ppc only 177204076Spjd 178204076Spjd// (a + ib) / (c + id) 179204076Spjd 180204076Spjd float _Complex __divsc3( float a, float b, float c, float d); 181204076Spjd double _Complex __divdc3(double a, double b, double c, double d); 182204076Spjdlong double _Complex __divxc3(long double a, long double b, 183204076Spjd long double c, long double d); 184204076Spjdlong double _Complex __divtc3(long double a, long double b, 185225787Spjd long double c, long double d); // ppc only 186225787Spjd 187204076Spjd 188204076Spjd// Runtime support 189204076Spjd 190204076Spjd// __clear_cache() is used to tell process that new instructions have been 191204076Spjd// written to an address range. Necessary on processors that do not have 192204076Spjd// a unified instuction and data cache. 193220522Strocinyvoid __clear_cache(void* start, void* end); 194220522Strociny 195220522Strociny// __enable_execute_stack() is used with nested functions when a trampoline 196220522Strociny// function is written onto the stack and that page range needs to be made 197204076Spjd// executable. 198220522Strocinyvoid __enable_execute_stack(void* addr); 199229945Spjd 200204076Spjd// __gcc_personality_v0() is normally only called by the system unwinder. 201204076Spjd// C code (as opposed to C++) normally does not need a personality function 202204076Spjd// because there are no catch clauses or destructors to be run. But there 203204076Spjd// is a C language extension __attribute__((cleanup(func))) which marks local 204204076Spjd// variables as needing the cleanup function "func" to be run when the 205204076Spjd// variable goes out of scope. That includes when an exception is thrown, 206204076Spjd// so a personality handler is needed. 207204076Spjd_Unwind_Reason_Code __gcc_personality_v0(int version, _Unwind_Action actions, 208204076Spjd uint64_t exceptionClass, struct _Unwind_Exception* exceptionObject, 209219351Spjd _Unwind_Context_t context); 210219351Spjd 211204076Spjd// for use with some implementations of assert() in <assert.h> 212219351Spjdvoid __eprintf(const char* format, const char* assertion_expression, 213204076Spjd const char* line, const char* file); 214204076Spjd 215204076Spjd 216204076Spjd 217204076Spjd// Power PC specific functions 218204076Spjd 219204076Spjd// There is no C interface to the saveFP/restFP functions. They are helper 220204076Spjd// functions called by the prolog and epilog of functions that need to save 221204076Spjd// a number of non-volatile float point registers. 222204076SpjdsaveFP 223restFP 224 225// PowerPC has a standard template for trampoline functions. This function 226// generates a custom trampoline function with the specific realFunc 227// and localsPtr values. 228void __trampoline_setup(uint32_t* trampOnStack, int trampSizeAllocated, 229 const void* realFunc, void* localsPtr); 230 231// adds two 128-bit double-double precision values ( x + y ) 232long double __gcc_qadd(long double x, long double y); 233 234// subtracts two 128-bit double-double precision values ( x - y ) 235long double __gcc_qsub(long double x, long double y); 236 237// multiples two 128-bit double-double precision values ( x * y ) 238long double __gcc_qmul(long double x, long double y); 239 240// divides two 128-bit double-double precision values ( x / y ) 241long double __gcc_qdiv(long double a, long double b); 242 243 244// ARM specific functions 245 246// There is no C interface to the switch* functions. These helper functions 247// are only needed by Thumb1 code for efficient switch table generation. 248switch16 249switch32 250switch8 251switchu8 252 253// There is no C interface to the *_vfp_d8_d15_regs functions. There are 254// called in the prolog and epilog of Thumb1 functions. When the C++ ABI use 255// SJLJ for exceptions, each function with a catch clause or destuctors needs 256// to save and restore all registers in it prolog and epliog. But there is 257// no way to access vector and high float registers from thumb1 code, so the 258// compiler must add call outs to these helper functions in the prolog and 259// epilog. 260restore_vfp_d8_d15_regs 261save_vfp_d8_d15_regs 262 263 264// Note: long ago ARM processors did not have floating point hardware support. 265// Floating point was done in software and floating point parameters were 266// passed in integer registers. When hardware support was added for floating 267// point, new *vfp functions were added to do the same operations but with 268// floating point parameters in floating point registers. 269 270// Undocumented functions 271 272float __addsf3vfp(float a, float b); // Appears to return a + b 273double __adddf3vfp(double a, double b); // Appears to return a + b 274float __divsf3vfp(float a, float b); // Appears to return a / b 275double __divdf3vfp(double a, double b); // Appears to return a / b 276int __eqsf2vfp(float a, float b); // Appears to return one 277 // iff a == b and neither is NaN. 278int __eqdf2vfp(double a, double b); // Appears to return one 279 // iff a == b and neither is NaN. 280double __extendsfdf2vfp(float a); // Appears to convert from 281 // float to double. 282int __fixdfsivfp(double a); // Appears to convert from 283 // double to int. 284int __fixsfsivfp(float a); // Appears to convert from 285 // float to int. 286unsigned int __fixunssfsivfp(float a); // Appears to convert from 287 // float to unsigned int. 288unsigned int __fixunsdfsivfp(double a); // Appears to convert from 289 // double to unsigned int. 290double __floatsidfvfp(int a); // Appears to convert from 291 // int to double. 292float __floatsisfvfp(int a); // Appears to convert from 293 // int to float. 294double __floatunssidfvfp(unsigned int a); // Appears to convert from 295 // unisgned int to double. 296float __floatunssisfvfp(unsigned int a); // Appears to convert from 297 // unisgned int to float. 298int __gedf2vfp(double a, double b); // Appears to return __gedf2 299 // (a >= b) 300int __gesf2vfp(float a, float b); // Appears to return __gesf2 301 // (a >= b) 302int __gtdf2vfp(double a, double b); // Appears to return __gtdf2 303 // (a > b) 304int __gtsf2vfp(float a, float b); // Appears to return __gtsf2 305 // (a > b) 306int __ledf2vfp(double a, double b); // Appears to return __ledf2 307 // (a <= b) 308int __lesf2vfp(float a, float b); // Appears to return __lesf2 309 // (a <= b) 310int __ltdf2vfp(double a, double b); // Appears to return __ltdf2 311 // (a < b) 312int __ltsf2vfp(float a, float b); // Appears to return __ltsf2 313 // (a < b) 314double __muldf3vfp(double a, double b); // Appears to return a * b 315float __mulsf3vfp(float a, float b); // Appears to return a * b 316int __nedf2vfp(double a, double b); // Appears to return __nedf2 317 // (a != b) 318double __negdf2vfp(double a); // Appears to return -a 319float __negsf2vfp(float a); // Appears to return -a 320float __negsf2vfp(float a); // Appears to return -a 321double __subdf3vfp(double a, double b); // Appears to return a - b 322float __subsf3vfp(float a, float b); // Appears to return a - b 323float __truncdfsf2vfp(double a); // Appears to convert from 324 // double to float. 325int __unorddf2vfp(double a, double b); // Appears to return __unorddf2 326int __unordsf2vfp(float a, float b); // Appears to return __unordsf2 327 328 329Preconditions are listed for each function at the definition when there are any. 330Any preconditions reflect the specification at 331http://gcc.gnu.org/onlinedocs/gccint/Libgcc.html#Libgcc. 332 333Assumptions are listed in "int_lib.h", and in individual files. Where possible 334assumptions are checked at compile time. 335