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Diffstat (limited to 'contrib/llvm-project/compiler-rt/lib/builtins/fp_compare_impl.inc')
-rw-r--r-- | contrib/llvm-project/compiler-rt/lib/builtins/fp_compare_impl.inc | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/contrib/llvm-project/compiler-rt/lib/builtins/fp_compare_impl.inc b/contrib/llvm-project/compiler-rt/lib/builtins/fp_compare_impl.inc new file mode 100644 index 000000000000..a9a4f6fbf5df --- /dev/null +++ b/contrib/llvm-project/compiler-rt/lib/builtins/fp_compare_impl.inc @@ -0,0 +1,119 @@ +//===-- lib/fp_compare_impl.inc - Floating-point comparison -------*- C -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#include "fp_lib.h" + +// GCC uses long (at least for x86_64) as the return type of the comparison +// functions. We need to ensure that the return value is sign-extended in the +// same way as GCC expects (since otherwise GCC-generated __builtin_isinf +// returns true for finite 128-bit floating-point numbers). +#ifdef __aarch64__ +// AArch64 GCC overrides libgcc_cmp_return to use int instead of long. +typedef int CMP_RESULT; +#elif __SIZEOF_POINTER__ == 8 && __SIZEOF_LONG__ == 4 +// LLP64 ABIs use long long instead of long. +typedef long long CMP_RESULT; +#elif __AVR__ +// AVR uses a single byte for the return value. +typedef char CMP_RESULT; +#else +// Otherwise the comparison functions return long. +typedef long CMP_RESULT; +#endif + +#if !defined(__clang__) && defined(__GNUC__) +// GCC uses a special __libgcc_cmp_return__ mode to define the return type, so +// check that we are ABI-compatible when compiling the builtins with GCC. +typedef int GCC_CMP_RESULT __attribute__((__mode__(__libgcc_cmp_return__))); +_Static_assert(sizeof(GCC_CMP_RESULT) == sizeof(CMP_RESULT), + "SOFTFP ABI not compatible with GCC"); +#endif + +enum { + LE_LESS = -1, + LE_EQUAL = 0, + LE_GREATER = 1, + LE_UNORDERED = 1, +}; + +static inline CMP_RESULT __leXf2__(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; + } else { + // 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). + if (aInt > bInt) + return LE_LESS; + else if (aInt == bInt) + return LE_EQUAL; + else + return LE_GREATER; + } +} + +enum { + GE_LESS = -1, + GE_EQUAL = 0, + GE_GREATER = 1, + GE_UNORDERED = -1 // Note: different from LE_UNORDERED +}; + +static inline CMP_RESULT __geXf2__(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; + } +} + +static inline CMP_RESULT __unordXf2__(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; +} |