Index: lib/builtins/comparetf2.c =================================================================== --- /dev/null +++ lib/builtins/comparetf2.c @@ -0,0 +1,136 @@ +//===-- lib/comparetf2.c - Quad-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-float comparison routines: +// +// __eqtf2 __getf2 __unordtf2 +// __letf2 __gttf2 +// __lttf2 +// __netf2 +// +// 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: +// +// __letf2(a,b) returns -1 if a < b +// 0 if a == b +// 1 if a > b +// 1 if either a or b is NaN +// +// __getf2(a,b) returns -1 if a < b +// 0 if a == b +// 1 if a > b +// -1 if either a or b is NaN +// +// __unordtf2(a,b) returns 0 if both a and b are numbers +// 1 if either a or b is NaN +// +// Note that __letf2( ) and __getf2( ) are identical except in their handling of +// NaN values. +// +//===----------------------------------------------------------------------===// + +// __uint128_t is undefined in 32-bit machine toolchain +#if defined(__SIZEOF_INT128__) && __SIZEOF_INT128__ == 16 + +#define QUAD_PRECISION +#include "fp_lib.h" + +enum LE_RESULT { + LE_LESS = -1, + LE_EQUAL = 0, + LE_GREATER = 1, + LE_UNORDERED = 1 +}; + +enum LE_RESULT __letf2(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 floating-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; + } +} + +enum GE_RESULT { + GE_LESS = -1, + GE_EQUAL = 0, + GE_GREATER = 1, + GE_UNORDERED = -1 // Note: different from LE_UNORDERED +}; + +enum GE_RESULT __getf2(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; + } +} + +int __unordtf2(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 preceeding routines. + +enum LE_RESULT __eqtf2(fp_t a, fp_t b) { + return __letf2(a, b); +} + +enum LE_RESULT __lttf2(fp_t a, fp_t b) { + return __letf2(a, b); +} + +enum LE_RESULT __netf2(fp_t a, fp_t b) { + return __letf2(a, b); +} + +enum GE_RESULT __gttf2(fp_t a, fp_t b) { + return __getf2(a, b); +} + +#endif