1//===-- lib/comparedf2.c - Double-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// __eqdf2 __gedf2 __unorddf2 13// __ledf2 __gtdf2 14// __ltdf2 15// __nedf2 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// __ledf2(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// __gedf2(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// __unorddf2(a,b) returns 0 if both a and b are numbers 33// 1 if either a or b is NaN 34// 35// Note that __ledf2( ) and __gedf2( ) are identical except in their handling of 36// NaN values. 37// 38//===----------------------------------------------------------------------===// 39 40#define DOUBLE_PRECISION 41#include "fp_lib.h" 42 43enum LE_RESULT { 44 LE_LESS = -1, 45 LE_EQUAL = 0, 46 LE_GREATER = 1, 47 LE_UNORDERED = 1 48}; 49 50COMPILER_RT_ABI enum LE_RESULT 51__ledf2(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 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 else { 77 if (aInt > bInt) return LE_LESS; 78 else if (aInt == bInt) return LE_EQUAL; 79 else return LE_GREATER; 80 } 81} 82 83#if defined(__ELF__) 84// Alias for libgcc compatibility 85FNALIAS(__cmpdf2, __ledf2); 86#endif 87 88enum GE_RESULT { 89 GE_LESS = -1, 90 GE_EQUAL = 0, 91 GE_GREATER = 1, 92 GE_UNORDERED = -1 // Note: different from LE_UNORDERED 93}; 94 95COMPILER_RT_ABI enum GE_RESULT 96__gedf2(fp_t a, fp_t b) { 97 98 const srep_t aInt = toRep(a); 99 const srep_t bInt = toRep(b); 100 const rep_t aAbs = aInt & absMask; 101 const rep_t bAbs = bInt & absMask; 102 103 if (aAbs > infRep || bAbs > infRep) return GE_UNORDERED; 104 if ((aAbs | bAbs) == 0) return GE_EQUAL; 105 if ((aInt & bInt) >= 0) { 106 if (aInt < bInt) return GE_LESS; 107 else if (aInt == bInt) return GE_EQUAL; 108 else return GE_GREATER; 109 } else { 110 if (aInt > bInt) return GE_LESS; 111 else if (aInt == bInt) return GE_EQUAL; 112 else return GE_GREATER; 113 } 114} 115 116ARM_EABI_FNALIAS(dcmpun, unorddf2) 117 118COMPILER_RT_ABI int 119__unorddf2(fp_t a, fp_t b) { 120 const rep_t aAbs = toRep(a) & absMask; 121 const rep_t bAbs = toRep(b) & absMask; 122 return aAbs > infRep || bAbs > infRep; 123} 124 125// The following are alternative names for the preceding routines. 126 127COMPILER_RT_ABI enum LE_RESULT 128__eqdf2(fp_t a, fp_t b) { 129 return __ledf2(a, b); 130} 131 132COMPILER_RT_ABI enum LE_RESULT 133__ltdf2(fp_t a, fp_t b) { 134 return __ledf2(a, b); 135} 136 137COMPILER_RT_ABI enum LE_RESULT 138__nedf2(fp_t a, fp_t b) { 139 return __ledf2(a, b); 140} 141 142COMPILER_RT_ABI enum GE_RESULT 143__gtdf2(fp_t a, fp_t b) { 144 return __gedf2(a, b); 145} 146 147