llvm-project/compiler-rt/lib/builtins/comparesf2.c

154 lines
4.3 KiB
C

//===-- lib/comparesf2.c - Single-precision comparisons -----------*- C -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the following soft-fp_t comparison routines:
//
// __eqsf2 __gesf2 __unordsf2
// __lesf2 __gtsf2
// __ltsf2
// __nesf2
//
// The semantics of the routines grouped in each column are identical, so there
// is a single implementation for each, and wrappers to provide the other names.
//
// The main routines behave as follows:
//
// __lesf2(a,b) returns -1 if a < b
// 0 if a == b
// 1 if a > b
// 1 if either a or b is NaN
//
// __gesf2(a,b) returns -1 if a < b
// 0 if a == b
// 1 if a > b
// -1 if either a or b is NaN
//
// __unordsf2(a,b) returns 0 if both a and b are numbers
// 1 if either a or b is NaN
//
// Note that __lesf2( ) and __gesf2( ) are identical except in their handling of
// NaN values.
//
//===----------------------------------------------------------------------===//
#define SINGLE_PRECISION
#include "fp_lib.h"
enum LE_RESULT {
LE_LESS = -1,
LE_EQUAL = 0,
LE_GREATER = 1,
LE_UNORDERED = 1
};
COMPILER_RT_ABI enum LE_RESULT
__lesf2(fp_t a, fp_t b) {
const srep_t aInt = toRep(a);
const srep_t bInt = toRep(b);
const rep_t aAbs = aInt & absMask;
const rep_t bAbs = bInt & absMask;
// If either a or b is NaN, they are unordered.
if (aAbs > infRep || bAbs > infRep) return LE_UNORDERED;
// If a and b are both zeros, they are equal.
if ((aAbs | bAbs) == 0) return LE_EQUAL;
// If at least one of a and b is positive, we get the same result comparing
// a and b as signed integers as we would with a fp_ting-point compare.
if ((aInt & bInt) >= 0) {
if (aInt < bInt) return LE_LESS;
else if (aInt == bInt) return LE_EQUAL;
else return LE_GREATER;
}
// Otherwise, both are negative, so we need to flip the sense of the
// comparison to get the correct result. (This assumes a twos- or ones-
// complement integer representation; if integers are represented in a
// sign-magnitude representation, then this flip is incorrect).
else {
if (aInt > bInt) return LE_LESS;
else if (aInt == bInt) return LE_EQUAL;
else return LE_GREATER;
}
}
#if defined(__ELF__)
// Alias for libgcc compatibility
FNALIAS(__cmpsf2, __lesf2);
#endif
enum GE_RESULT {
GE_LESS = -1,
GE_EQUAL = 0,
GE_GREATER = 1,
GE_UNORDERED = -1 // Note: different from LE_UNORDERED
};
COMPILER_RT_ABI enum GE_RESULT
__gesf2(fp_t a, fp_t b) {
const srep_t aInt = toRep(a);
const srep_t bInt = toRep(b);
const rep_t aAbs = aInt & absMask;
const rep_t bAbs = bInt & absMask;
if (aAbs > infRep || bAbs > infRep) return GE_UNORDERED;
if ((aAbs | bAbs) == 0) return GE_EQUAL;
if ((aInt & bInt) >= 0) {
if (aInt < bInt) return GE_LESS;
else if (aInt == bInt) return GE_EQUAL;
else return GE_GREATER;
} else {
if (aInt > bInt) return GE_LESS;
else if (aInt == bInt) return GE_EQUAL;
else return GE_GREATER;
}
}
COMPILER_RT_ABI int
__unordsf2(fp_t a, fp_t b) {
const rep_t aAbs = toRep(a) & absMask;
const rep_t bAbs = toRep(b) & absMask;
return aAbs > infRep || bAbs > infRep;
}
// The following are alternative names for the preceding routines.
COMPILER_RT_ABI enum LE_RESULT
__eqsf2(fp_t a, fp_t b) {
return __lesf2(a, b);
}
COMPILER_RT_ABI enum LE_RESULT
__ltsf2(fp_t a, fp_t b) {
return __lesf2(a, b);
}
COMPILER_RT_ABI enum LE_RESULT
__nesf2(fp_t a, fp_t b) {
return __lesf2(a, b);
}
COMPILER_RT_ABI enum GE_RESULT
__gtsf2(fp_t a, fp_t b) {
return __gesf2(a, b);
}
#if defined(__ARM_EABI__)
#if defined(COMPILER_RT_ARMHF_TARGET)
AEABI_RTABI int __aeabi_fcmpun(fp_t a, fp_t b) {
return __unordsf2(a, b);
}
#else
AEABI_RTABI int __aeabi_fcmpun(fp_t a, fp_t b) COMPILER_RT_ALIAS(__unordsf2);
#endif
#endif