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diff --git a/lib/builtins/README.txt b/lib/builtins/README.txt new file mode 100644 index 000000000..1c08e7415 --- /dev/null +++ b/lib/builtins/README.txt @@ -0,0 +1,343 @@ +Compiler-RT +================================ + +This directory and its subdirectories contain source code for the compiler +support routines. + +Compiler-RT is open source software. You may freely distribute it under the +terms of the license agreement found in LICENSE.txt. + +================================ + +This is a replacement library for libgcc. Each function is contained +in its own file. Each function has a corresponding unit test under +test/Unit. + +A rudimentary script to test each file is in the file called +test/Unit/test. + +Here is the specification for this library: + +http://gcc.gnu.org/onlinedocs/gccint/Libgcc.html#Libgcc + +Here is a synopsis of the contents of this library: + +typedef int si_int; +typedef unsigned su_int; + +typedef long long di_int; +typedef unsigned long long du_int; + +// Integral bit manipulation + +di_int __ashldi3(di_int a, si_int b); // a << b +ti_int __ashlti3(ti_int a, si_int b); // a << b + +di_int __ashrdi3(di_int a, si_int b); // a >> b arithmetic (sign fill) +ti_int __ashrti3(ti_int a, si_int b); // a >> b arithmetic (sign fill) +di_int __lshrdi3(di_int a, si_int b); // a >> b logical (zero fill) +ti_int __lshrti3(ti_int a, si_int b); // a >> b logical (zero fill) + +si_int __clzsi2(si_int a); // count leading zeros +si_int __clzdi2(di_int a); // count leading zeros +si_int __clzti2(ti_int a); // count leading zeros +si_int __ctzsi2(si_int a); // count trailing zeros +si_int __ctzdi2(di_int a); // count trailing zeros +si_int __ctzti2(ti_int a); // count trailing zeros + +si_int __ffsdi2(di_int a); // find least significant 1 bit +si_int __ffsti2(ti_int a); // find least significant 1 bit + +si_int __paritysi2(si_int a); // bit parity +si_int __paritydi2(di_int a); // bit parity +si_int __parityti2(ti_int a); // bit parity + +si_int __popcountsi2(si_int a); // bit population +si_int __popcountdi2(di_int a); // bit population +si_int __popcountti2(ti_int a); // bit population + +uint32_t __bswapsi2(uint32_t a); // a byteswapped, arm only +uint64_t __bswapdi2(uint64_t a); // a byteswapped, arm only + +// Integral arithmetic + +di_int __negdi2 (di_int a); // -a +ti_int __negti2 (ti_int a); // -a +di_int __muldi3 (di_int a, di_int b); // a * b +ti_int __multi3 (ti_int a, ti_int b); // a * b +si_int __divsi3 (si_int a, si_int b); // a / b signed +di_int __divdi3 (di_int a, di_int b); // a / b signed +ti_int __divti3 (ti_int a, ti_int b); // a / b signed +su_int __udivsi3 (su_int n, su_int d); // a / b unsigned +du_int __udivdi3 (du_int a, du_int b); // a / b unsigned +tu_int __udivti3 (tu_int a, tu_int b); // a / b unsigned +si_int __modsi3 (si_int a, si_int b); // a % b signed +di_int __moddi3 (di_int a, di_int b); // a % b signed +ti_int __modti3 (ti_int a, ti_int b); // a % b signed +su_int __umodsi3 (su_int a, su_int b); // a % b unsigned +du_int __umoddi3 (du_int a, du_int b); // a % b unsigned +tu_int __umodti3 (tu_int a, tu_int b); // a % b unsigned +du_int __udivmoddi4(du_int a, du_int b, du_int* rem); // a / b, *rem = a % b unsigned +tu_int __udivmodti4(tu_int a, tu_int b, tu_int* rem); // a / b, *rem = a % b unsigned +su_int __udivmodsi4(su_int a, su_int b, su_int* rem); // a / b, *rem = a % b unsigned +si_int __divmodsi4(si_int a, si_int b, si_int* rem); // a / b, *rem = a % b signed + + + +// Integral arithmetic with trapping overflow + +si_int __absvsi2(si_int a); // abs(a) +di_int __absvdi2(di_int a); // abs(a) +ti_int __absvti2(ti_int a); // abs(a) + +si_int __negvsi2(si_int a); // -a +di_int __negvdi2(di_int a); // -a +ti_int __negvti2(ti_int a); // -a + +si_int __addvsi3(si_int a, si_int b); // a + b +di_int __addvdi3(di_int a, di_int b); // a + b +ti_int __addvti3(ti_int a, ti_int b); // a + b + +si_int __subvsi3(si_int a, si_int b); // a - b +di_int __subvdi3(di_int a, di_int b); // a - b +ti_int __subvti3(ti_int a, ti_int b); // a - b + +si_int __mulvsi3(si_int a, si_int b); // a * b +di_int __mulvdi3(di_int a, di_int b); // a * b +ti_int __mulvti3(ti_int a, ti_int b); // a * b + + +// Integral arithmetic which returns if overflow + +si_int __mulosi4(si_int a, si_int b, int* overflow); // a * b, overflow set to one if result not in signed range +di_int __mulodi4(di_int a, di_int b, int* overflow); // a * b, overflow set to one if result not in signed range +ti_int __muloti4(ti_int a, ti_int b, int* overflow); // a * b, overflow set to + one if result not in signed range + + +// Integral comparison: a < b -> 0 +// a == b -> 1 +// a > b -> 2 + +si_int __cmpdi2 (di_int a, di_int b); +si_int __cmpti2 (ti_int a, ti_int b); +si_int __ucmpdi2(du_int a, du_int b); +si_int __ucmpti2(tu_int a, tu_int b); + +// Integral / floating point conversion + +di_int __fixsfdi( float a); +di_int __fixdfdi( double a); +di_int __fixxfdi(long double a); + +ti_int __fixsfti( float a); +ti_int __fixdfti( double a); +ti_int __fixxfti(long double a); +uint64_t __fixtfdi(long double input); // ppc only, doesn't match documentation + +su_int __fixunssfsi( float a); +su_int __fixunsdfsi( double a); +su_int __fixunsxfsi(long double a); + +du_int __fixunssfdi( float a); +du_int __fixunsdfdi( double a); +du_int __fixunsxfdi(long double a); + +tu_int __fixunssfti( float a); +tu_int __fixunsdfti( double a); +tu_int __fixunsxfti(long double a); +uint64_t __fixunstfdi(long double input); // ppc only + +float __floatdisf(di_int a); +double __floatdidf(di_int a); +long double __floatdixf(di_int a); +long double __floatditf(int64_t a); // ppc only + +float __floattisf(ti_int a); +double __floattidf(ti_int a); +long double __floattixf(ti_int a); + +float __floatundisf(du_int a); +double __floatundidf(du_int a); +long double __floatundixf(du_int a); +long double __floatunditf(uint64_t a); // ppc only + +float __floatuntisf(tu_int a); +double __floatuntidf(tu_int a); +long double __floatuntixf(tu_int a); + +// Floating point raised to integer power + +float __powisf2( float a, si_int b); // a ^ b +double __powidf2( double a, si_int b); // a ^ b +long double __powixf2(long double a, si_int b); // a ^ b +long double __powitf2(long double a, si_int b); // ppc only, a ^ b + +// Complex arithmetic + +// (a + ib) * (c + id) + + float _Complex __mulsc3( float a, float b, float c, float d); + double _Complex __muldc3(double a, double b, double c, double d); +long double _Complex __mulxc3(long double a, long double b, + long double c, long double d); +long double _Complex __multc3(long double a, long double b, + long double c, long double d); // ppc only + +// (a + ib) / (c + id) + + float _Complex __divsc3( float a, float b, float c, float d); + double _Complex __divdc3(double a, double b, double c, double d); +long double _Complex __divxc3(long double a, long double b, + long double c, long double d); +long double _Complex __divtc3(long double a, long double b, + long double c, long double d); // ppc only + + +// Runtime support + +// __clear_cache() is used to tell process that new instructions have been +// written to an address range. Necessary on processors that do not have +// a unified instruction and data cache. +void __clear_cache(void* start, void* end); + +// __enable_execute_stack() is used with nested functions when a trampoline +// function is written onto the stack and that page range needs to be made +// executable. +void __enable_execute_stack(void* addr); + +// __gcc_personality_v0() is normally only called by the system unwinder. +// C code (as opposed to C++) normally does not need a personality function +// because there are no catch clauses or destructors to be run. But there +// is a C language extension __attribute__((cleanup(func))) which marks local +// variables as needing the cleanup function "func" to be run when the +// variable goes out of scope. That includes when an exception is thrown, +// so a personality handler is needed. +_Unwind_Reason_Code __gcc_personality_v0(int version, _Unwind_Action actions, + uint64_t exceptionClass, struct _Unwind_Exception* exceptionObject, + _Unwind_Context_t context); + +// for use with some implementations of assert() in <assert.h> +void __eprintf(const char* format, const char* assertion_expression, + const char* line, const char* file); + + + +// Power PC specific functions + +// There is no C interface to the saveFP/restFP functions. They are helper +// functions called by the prolog and epilog of functions that need to save +// a number of non-volatile float point registers. +saveFP +restFP + +// PowerPC has a standard template for trampoline functions. This function +// generates a custom trampoline function with the specific realFunc +// and localsPtr values. +void __trampoline_setup(uint32_t* trampOnStack, int trampSizeAllocated, + const void* realFunc, void* localsPtr); + +// adds two 128-bit double-double precision values ( x + y ) +long double __gcc_qadd(long double x, long double y); + +// subtracts two 128-bit double-double precision values ( x - y ) +long double __gcc_qsub(long double x, long double y); + +// multiples two 128-bit double-double precision values ( x * y ) +long double __gcc_qmul(long double x, long double y); + +// divides two 128-bit double-double precision values ( x / y ) +long double __gcc_qdiv(long double a, long double b); + + +// ARM specific functions + +// There is no C interface to the switch* functions. These helper functions +// are only needed by Thumb1 code for efficient switch table generation. +switch16 +switch32 +switch8 +switchu8 + +// There is no C interface to the *_vfp_d8_d15_regs functions. There are +// called in the prolog and epilog of Thumb1 functions. When the C++ ABI use +// SJLJ for exceptions, each function with a catch clause or destuctors needs +// to save and restore all registers in it prolog and epliog. But there is +// no way to access vector and high float registers from thumb1 code, so the +// compiler must add call outs to these helper functions in the prolog and +// epilog. +restore_vfp_d8_d15_regs +save_vfp_d8_d15_regs + + +// Note: long ago ARM processors did not have floating point hardware support. +// Floating point was done in software and floating point parameters were +// passed in integer registers. When hardware support was added for floating +// point, new *vfp functions were added to do the same operations but with +// floating point parameters in floating point registers. + +// Undocumented functions + +float __addsf3vfp(float a, float b); // Appears to return a + b +double __adddf3vfp(double a, double b); // Appears to return a + b +float __divsf3vfp(float a, float b); // Appears to return a / b +double __divdf3vfp(double a, double b); // Appears to return a / b +int __eqsf2vfp(float a, float b); // Appears to return one + // iff a == b and neither is NaN. +int __eqdf2vfp(double a, double b); // Appears to return one + // iff a == b and neither is NaN. +double __extendsfdf2vfp(float a); // Appears to convert from + // float to double. +int __fixdfsivfp(double a); // Appears to convert from + // double to int. +int __fixsfsivfp(float a); // Appears to convert from + // float to int. +unsigned int __fixunssfsivfp(float a); // Appears to convert from + // float to unsigned int. +unsigned int __fixunsdfsivfp(double a); // Appears to convert from + // double to unsigned int. +double __floatsidfvfp(int a); // Appears to convert from + // int to double. +float __floatsisfvfp(int a); // Appears to convert from + // int to float. +double __floatunssidfvfp(unsigned int a); // Appears to convert from + // unisgned int to double. +float __floatunssisfvfp(unsigned int a); // Appears to convert from + // unisgned int to float. +int __gedf2vfp(double a, double b); // Appears to return __gedf2 + // (a >= b) +int __gesf2vfp(float a, float b); // Appears to return __gesf2 + // (a >= b) +int __gtdf2vfp(double a, double b); // Appears to return __gtdf2 + // (a > b) +int __gtsf2vfp(float a, float b); // Appears to return __gtsf2 + // (a > b) +int __ledf2vfp(double a, double b); // Appears to return __ledf2 + // (a <= b) +int __lesf2vfp(float a, float b); // Appears to return __lesf2 + // (a <= b) +int __ltdf2vfp(double a, double b); // Appears to return __ltdf2 + // (a < b) +int __ltsf2vfp(float a, float b); // Appears to return __ltsf2 + // (a < b) +double __muldf3vfp(double a, double b); // Appears to return a * b +float __mulsf3vfp(float a, float b); // Appears to return a * b +int __nedf2vfp(double a, double b); // Appears to return __nedf2 + // (a != b) +double __negdf2vfp(double a); // Appears to return -a +float __negsf2vfp(float a); // Appears to return -a +float __negsf2vfp(float a); // Appears to return -a +double __subdf3vfp(double a, double b); // Appears to return a - b +float __subsf3vfp(float a, float b); // Appears to return a - b +float __truncdfsf2vfp(double a); // Appears to convert from + // double to float. +int __unorddf2vfp(double a, double b); // Appears to return __unorddf2 +int __unordsf2vfp(float a, float b); // Appears to return __unordsf2 + + +Preconditions are listed for each function at the definition when there are any. +Any preconditions reflect the specification at +http://gcc.gnu.org/onlinedocs/gccint/Libgcc.html#Libgcc. + +Assumptions are listed in "int_lib.h", and in individual files. Where possible +assumptions are checked at compile time. |