llvm-capstone/compiler-rt

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
tu_int __udivmodti4(tu_int a, tu_int b, tu_int* rem);  // a / b, *rem = a % b

//  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 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

// Undocumented functions

float  __addsf3vfp(float a, float b);   // arm only.  Appears to return a + b
double __adddf3vfp(double a, double b); // arm only.  Appears to return a + b
float  __divsf3vfp(float a, float b);   // arm only.  Appears to return a / b
double __divdf3vfp(double a, double b); // arm only.  Appears to return a / b
int    __eqsf2vfp(float a, float b);    // arm only.  Appears to return  one
                                        //     iff a == b and neither is NaN.
int    __eqdf2vfp(double a, double b);  // arm only.  Appears to return  one
                                        //     iff a == b and neither is NaN.
double __extendsfdf2vfp(float a);       // arm only.  Appears to convert from
                                        //     float to double.
int    __fixdfsivfp(double a);          // arm only.  Appears to convert from
                                        //     double to int.
int    __fixsfsivfp(float a);           // arm only.  Appears to convert from
                                        //     float to int.
unsigned int __fixunssfsivfp(float a);  // arm only.  Appears to convert from
                                        //     float to unsigned int.
unsigned int __fixunsdfsivfp(double a); // arm only.  Appears to convert from
                                        //     double to unsigned int.
double __floatsidfvfp(int a);           // arm only.  Appears to convert from
                                        //     int to double.
float __floatsisfvfp(int a);            // arm only.  Appears to convert from
                                        //     int to float.
double __floatunssidfvfp(unsigned int a); // arm only. Appears to convert from
                                        //     unisgned int to double.
float __floatunssisfvfp(unsigned int a); // arm only.  Appears to convert from
                                        //     unisgned int to float.
long double __gcc_qadd(long double x, long double y);  // ppc only.  Appears to
                                        //     return x + y.
long double __gcc_qdiv(long double a, long double b);  // ppc only.  Appears to
                                        //     return x / y.
long double __gcc_qmul(long double x, long double y);  // ppc only.  Appears to
                                        //     return x * y.
long double __gcc_qsub(long double x, long double y);  // ppc only.  Appears to
                                        //     return x - y.
int __gedf2vfp(double a, double b);     // arm only.  Appears to return __gedf2
                                        //     (a >= b)
int __gesf2vfp(float a, float b);       // arm only.  Appears to return __gesf2
                                        //     (a >= b)
int __gtdf2vfp(double a, double b);     // arm only.  Appears to return __gtdf2
                                        //     (a > b)
int __gtsf2vfp(float a, float b);       // arm only.  Appears to return __gtsf2
                                        //     (a > b)
int __ledf2vfp(double a, double b);     // arm only.  Appears to return __ledf2
                                        //     (a <= b)
int __lesf2vfp(float a, float b);       // arm only.  Appears to return __lesf2
                                        //     (a <= b)
int __ltdf2vfp(double a, double b);     // arm only.  Appears to return __ltdf2
                                        //     (a < b)
int __ltsf2vfp(float a, float b);       // arm only.  Appears to return __ltsf2
                                        //     (a < b)
double __muldf3vfp(double a, double b); // arm only.  Appears to return a * b
float __mulsf3vfp(float a, float b);    // arm only.  Appears to return a * b
int __nedf2vfp(double a, double b);     // arm only.  Appears to return __nedf2
                                        //     (a != b)
double __negdf2vfp(double a);           // arm only.  Appears to return -a
float __negsf2vfp(float a);             // arm only.  Appears to return -a
float __negsf2vfp(float a);             // arm only.  Appears to return -a
double __subdf3vfp(double a, double b); // arm only.  Appears to return a - b
float __subsf3vfp(float a, float b);    // arm only.  Appears to return a - b
float __truncdfsf2vfp(double a);        // arm only.  Appears to convert from
                                        //     double to float.
int __unorddf2vfp(double a, double b);  // arm only.  Appears to return
                                        //     __unorddf2
int __unordsf2vfp(float a, float b);    // arm only.  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.