1 2/*============================================================================ 3 4This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic 5Package, Release 3e, by John R. Hauser. 6 7Copyright 2011, 2012, 2013, 2014, 2017 The Regents of the University of 8California. All rights reserved. 9 10Redistribution and use in source and binary forms, with or without 11modification, 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 24THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS", AND ANY 25EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 26WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE 27DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY 28DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 29(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 30LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 31ON 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 33SOFTWARE, 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 46void 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 61void 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_raiseFlags( 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#ifdef SOFTFLOAT_ROUND_ODD 114 case softfloat_round_odd: 115 goto mag1; 116#endif 117 } 118 uiZ64 = signUI64; 119 sigZ = 0; 120 goto uiZ; 121 mag1: 122 uiZ64 = signUI64 | 0x3FFF; 123 sigZ = UINT64_C( 0x8000000000000000 ); 124 goto uiZ; 125 } 126 /*------------------------------------------------------------------------ 127 *------------------------------------------------------------------------*/ 128 if ( 0x403E <= exp ) { 129 if ( exp == 0x7FFF ) { 130 if ( sigA & UINT64_C( 0x7FFFFFFFFFFFFFFF ) ) { 131 softfloat_propagateNaNExtF80M( aSPtr, 0, zSPtr ); 132 return; 133 } 134 sigZ = UINT64_C( 0x8000000000000000 ); 135 } else { 136 sigZ = sigA; 137 } 138 uiZ64 = signUI64 | exp; 139 goto uiZ; 140 } 141 /*------------------------------------------------------------------------ 142 *------------------------------------------------------------------------*/ 143 uiZ64 = signUI64 | exp; 144 lastBitMask = (uint64_t) 1<<(0x403E - exp); 145 roundBitsMask = lastBitMask - 1; 146 sigZ = sigA; 147 if ( roundingMode == softfloat_round_near_maxMag ) { 148 sigZ += lastBitMask>>1; 149 } else if ( roundingMode == softfloat_round_near_even ) { 150 sigZ += lastBitMask>>1; 151 if ( !(sigZ & roundBitsMask) ) sigZ &= ~lastBitMask; 152 } else if ( 153 roundingMode == (signUI64 ? softfloat_round_min : softfloat_round_max) 154 ) { 155 sigZ += roundBitsMask; 156 } 157 sigZ &= ~roundBitsMask; 158 if ( !sigZ ) { 159 ++uiZ64; 160 sigZ = UINT64_C( 0x8000000000000000 ); 161 } 162 if ( sigZ != sigA ) { 163#ifdef SOFTFLOAT_ROUND_ODD 164 if ( roundingMode == softfloat_round_odd ) sigZ |= lastBitMask; 165#endif 166 if ( exact ) softfloat_raiseFlags( softfloat_flag_inexact ); 167 } 168 uiZ: 169 zSPtr->signExp = uiZ64; 170 zSPtr->signif = sigZ; 171 return; 172 173} 174 175#endif 176 177