1 2 /*============================================================================ 3 4 This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic 5 Package, Release 3a, by John R. Hauser. 6 7 Copyright 2011, 2012, 2013, 2014 The Regents of the University of California. 8 All rights reserved. 9 10 Redistribution and use in source and binary forms, with or without 11 modification, are permitted provided that the following conditions are met: 12 13 1. Redistributions of source code must retain the above copyright notice, 14 this list of conditions, and the following disclaimer. 15 16 2. Redistributions in binary form must reproduce the above copyright notice, 17 this list of conditions, and the following disclaimer in the documentation 18 and/or other materials provided with the distribution. 19 20 3. Neither the name of the University nor the names of its contributors may 21 be used to endorse or promote products derived from this software without 22 specific prior written permission. 23 24 THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS", AND ANY 25 EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 26 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE 27 DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY 28 DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 29 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 30 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 31 ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 32 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 33 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34 35 =============================================================================*/ 36 37 #include <stdbool.h> 38 #include <stdint.h> 39 #include "platform.h" 40 #include "internals.h" 41 #include "specialize.h" 42 #include "softfloat.h" 43 44 #ifdef SOFTFLOAT_FAST_INT64 45 46 void 47 extF80M_roundToInt( 48 const extFloat80_t *aPtr, 49 uint_fast8_t roundingMode, 50 bool exact, 51 extFloat80_t *zPtr 52 ) 53 { 54 55 *zPtr = extF80_roundToInt( *aPtr, roundingMode, exact ); 56 57 } 58 59 #else 60 61 void 62 extF80M_roundToInt( 63 const extFloat80_t *aPtr, 64 uint_fast8_t roundingMode, 65 bool exact, 66 extFloat80_t *zPtr 67 ) 68 { 69 const struct extFloat80M *aSPtr; 70 struct extFloat80M *zSPtr; 71 uint_fast16_t uiA64, signUI64; 72 int32_t exp; 73 uint64_t sigA; 74 uint_fast16_t uiZ64; 75 uint64_t sigZ, lastBitMask, roundBitsMask; 76 77 /*------------------------------------------------------------------------ 78 *------------------------------------------------------------------------*/ 79 aSPtr = (const struct extFloat80M *) aPtr; 80 zSPtr = (struct extFloat80M *) zPtr; 81 /*------------------------------------------------------------------------ 82 *------------------------------------------------------------------------*/ 83 uiA64 = aSPtr->signExp; 84 signUI64 = uiA64 & packToExtF80UI64( 1, 0 ); 85 exp = expExtF80UI64( uiA64 ); 86 sigA = aSPtr->signif; 87 /*------------------------------------------------------------------------ 88 *------------------------------------------------------------------------*/ 89 if ( ! (sigA & UINT64_C( 0x8000000000000000 )) && (exp != 0x7FFF) ) { 90 if ( ! sigA ) { 91 uiZ64 = signUI64; 92 sigZ = 0; 93 goto uiZ; 94 } 95 exp += softfloat_normExtF80SigM( &sigA ); 96 } 97 /*------------------------------------------------------------------------ 98 *------------------------------------------------------------------------*/ 99 if ( exp <= 0x3FFE ) { 100 if ( exact ) softfloat_exceptionFlags |= softfloat_flag_inexact; 101 switch ( roundingMode ) { 102 case softfloat_round_near_even: 103 if ( ! (sigA & UINT64_C( 0x7FFFFFFFFFFFFFFF )) ) break; 104 case softfloat_round_near_maxMag: 105 if ( exp == 0x3FFE ) goto mag1; 106 break; 107 case softfloat_round_min: 108 if ( signUI64 ) goto mag1; 109 break; 110 case softfloat_round_max: 111 if ( ! signUI64 ) goto mag1; 112 break; 113 } 114 uiZ64 = signUI64; 115 sigZ = 0; 116 goto uiZ; 117 mag1: 118 uiZ64 = signUI64 | 0x3FFF; 119 sigZ = UINT64_C( 0x8000000000000000 ); 120 goto uiZ; 121 } 122 /*------------------------------------------------------------------------ 123 *------------------------------------------------------------------------*/ 124 if ( 0x403E <= exp ) { 125 if ( exp == 0x7FFF ) { 126 if ( sigA & UINT64_C( 0x7FFFFFFFFFFFFFFF ) ) { 127 softfloat_propagateNaNExtF80M( aSPtr, 0, zSPtr ); 128 return; 129 } 130 sigZ = UINT64_C( 0x8000000000000000 ); 131 } else { 132 sigZ = sigA; 133 } 134 uiZ64 = signUI64 | exp; 135 goto uiZ; 136 } 137 /*------------------------------------------------------------------------ 138 *------------------------------------------------------------------------*/ 139 uiZ64 = signUI64 | exp; 140 lastBitMask = (uint64_t) 1<<(0x403E - exp); 141 roundBitsMask = lastBitMask - 1; 142 sigZ = sigA; 143 if ( roundingMode == softfloat_round_near_maxMag ) { 144 sigZ += lastBitMask>>1; 145 } else if ( roundingMode == softfloat_round_near_even ) { 146 sigZ += lastBitMask>>1; 147 if ( ! (sigZ & roundBitsMask) ) sigZ &= ~lastBitMask; 148 } else if ( roundingMode != softfloat_round_minMag ) { 149 if ( (signUI64 != 0) ^ (roundingMode == softfloat_round_max) ) { 150 sigZ += roundBitsMask; 151 } 152 } 153 sigZ &= ~roundBitsMask; 154 if ( ! sigZ ) { 155 ++uiZ64; 156 sigZ = UINT64_C( 0x8000000000000000 ); 157 } 158 if ( exact && (sigZ != sigA) ) { 159 softfloat_exceptionFlags |= softfloat_flag_inexact; 160 } 161 uiZ: 162 zSPtr->signExp = uiZ64; 163 zSPtr->signif = sigZ; 164 return; 165 166 } 167 168 #endif 169 170