1//===-- lib/comparetf2.c - Quad-precision comparisons -------------*- C -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is dual licensed under the MIT and the University of Illinois Open 6// Source Licenses. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// // This file implements the following soft-float comparison routines: 11// 12// __eqtf2 __getf2 __unordtf2 13// __letf2 __gttf2 14// __lttf2 15// __netf2 16// 17// The semantics of the routines grouped in each column are identical, so there 18// is a single implementation for each, and wrappers to provide the other names. 19// 20// The main routines behave as follows: 21// 22// __letf2(a,b) returns -1 if a < b 23// 0 if a == b 24// 1 if a > b 25// 1 if either a or b is NaN 26// 27// __getf2(a,b) returns -1 if a < b 28// 0 if a == b 29// 1 if a > b 30// -1 if either a or b is NaN 31// 32// __unordtf2(a,b) returns 0 if both a and b are numbers 33// 1 if either a or b is NaN 34// 35// Note that __letf2( ) and __getf2( ) are identical except in their handling of 36// NaN values. 37// 38//===----------------------------------------------------------------------===// 39 40#define QUAD_PRECISION 41#include "fp_lib.h" 42 43#if defined(CRT_HAS_128BIT) && defined(CRT_LDBL_128BIT) 44enum LE_RESULT { 45 LE_LESS = -1, 46 LE_EQUAL = 0, 47 LE_GREATER = 1, 48 LE_UNORDERED = 1 49}; 50 51COMPILER_RT_ABI enum LE_RESULT __letf2(fp_t a, fp_t b) { 52 53 const srep_t aInt = toRep(a); 54 const srep_t bInt = toRep(b); 55 const rep_t aAbs = aInt & absMask; 56 const rep_t bAbs = bInt & absMask; 57 58 // If either a or b is NaN, they are unordered. 59 if (aAbs > infRep || bAbs > infRep) return LE_UNORDERED; 60 61 // If a and b are both zeros, they are equal. 62 if ((aAbs | bAbs) == 0) return LE_EQUAL; 63 64 // If at least one of a and b is positive, we get the same result comparing 65 // a and b as signed integers as we would with a floating-point compare. 66 if ((aInt & bInt) >= 0) { 67 if (aInt < bInt) return LE_LESS; 68 else if (aInt == bInt) return LE_EQUAL; 69 else return LE_GREATER; 70 } 71 else { 72 // Otherwise, both are negative, so we need to flip the sense of the 73 // comparison to get the correct result. (This assumes a twos- or ones- 74 // complement integer representation; if integers are represented in a 75 // sign-magnitude representation, then this flip is incorrect). 76 if (aInt > bInt) return LE_LESS; 77 else if (aInt == bInt) return LE_EQUAL; 78 else return LE_GREATER; 79 } 80} 81 82#if defined(__ELF__) 83// Alias for libgcc compatibility 84FNALIAS(__cmptf2, __letf2); 85#endif 86 87enum GE_RESULT { 88 GE_LESS = -1, 89 GE_EQUAL = 0, 90 GE_GREATER = 1, 91 GE_UNORDERED = -1 // Note: different from LE_UNORDERED 92}; 93 94COMPILER_RT_ABI enum GE_RESULT __getf2(fp_t a, fp_t b) { 95 96 const srep_t aInt = toRep(a); 97 const srep_t bInt = toRep(b); 98 const rep_t aAbs = aInt & absMask; 99 const rep_t bAbs = bInt & absMask; 100 101 if (aAbs > infRep || bAbs > infRep) return GE_UNORDERED; 102 if ((aAbs | bAbs) == 0) return GE_EQUAL; 103 if ((aInt & bInt) >= 0) { 104 if (aInt < bInt) return GE_LESS; 105 else if (aInt == bInt) return GE_EQUAL; 106 else return GE_GREATER; 107 } else { 108 if (aInt > bInt) return GE_LESS; 109 else if (aInt == bInt) return GE_EQUAL; 110 else return GE_GREATER; 111 } 112} 113 114COMPILER_RT_ABI int __unordtf2(fp_t a, fp_t b) { 115 const rep_t aAbs = toRep(a) & absMask; 116 const rep_t bAbs = toRep(b) & absMask; 117 return aAbs > infRep || bAbs > infRep; 118} 119 120// The following are alternative names for the preceding routines. 121 122COMPILER_RT_ABI enum LE_RESULT __eqtf2(fp_t a, fp_t b) { 123 return __letf2(a, b); 124} 125 126COMPILER_RT_ABI enum LE_RESULT __lttf2(fp_t a, fp_t b) { 127 return __letf2(a, b); 128} 129 130COMPILER_RT_ABI enum LE_RESULT __netf2(fp_t a, fp_t b) { 131 return __letf2(a, b); 132} 133 134COMPILER_RT_ABI enum GE_RESULT __gttf2(fp_t a, fp_t b) { 135 return __getf2(a, b); 136} 137 138#endif 139