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 "softfloat.h" 42 43void 44 softfloat_roundPackMToF128M( 45 bool sign, int32_t exp, uint32_t *extSigPtr, uint32_t *zWPtr ) 46{ 47 uint_fast8_t roundingMode; 48 bool roundNearEven; 49 uint32_t sigExtra; 50 bool doIncrement, isTiny; 51 static const uint32_t maxSig[4] = 52 INIT_UINTM4( 0x0001FFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF ); 53 uint32_t ui, uj; 54 55 /*------------------------------------------------------------------------ 56 *------------------------------------------------------------------------*/ 57 roundingMode = softfloat_roundingMode; 58 roundNearEven = (roundingMode == softfloat_round_near_even); 59 sigExtra = extSigPtr[indexWordLo( 5 )]; 60 doIncrement = (0x80000000 <= sigExtra); 61 if ( ! roundNearEven && (roundingMode != softfloat_round_near_maxMag) ) { 62 doIncrement = 63 (roundingMode 64 == (sign ? softfloat_round_min : softfloat_round_max)) 65 && sigExtra; 66 } 67 /*------------------------------------------------------------------------ 68 *------------------------------------------------------------------------*/ 69 if ( 0x7FFD <= (uint32_t) exp ) { 70 if ( exp < 0 ) { 71 /*---------------------------------------------------------------- 72 *----------------------------------------------------------------*/ 73 isTiny = 74 (softfloat_detectTininess 75 == softfloat_tininess_beforeRounding) 76 || (exp < -1) 77 || ! doIncrement 78 || (softfloat_compare128M( 79 extSigPtr + indexMultiwordHi( 5, 4 ), maxSig ) 80 < 0); 81 softfloat_shiftRightJam160M( extSigPtr, -exp, extSigPtr ); 82 exp = 0; 83 sigExtra = extSigPtr[indexWordLo( 5 )]; 84 if ( isTiny && sigExtra ) { 85 softfloat_raiseFlags( softfloat_flag_underflow ); 86 } 87 doIncrement = (0x80000000 <= sigExtra); 88 if ( 89 ! roundNearEven 90 && (roundingMode != softfloat_round_near_maxMag) 91 ) { 92 doIncrement = 93 (roundingMode 94 == (sign ? softfloat_round_min : softfloat_round_max)) 95 && sigExtra; 96 } 97 } else if ( 98 (0x7FFD < exp) 99 || ((exp == 0x7FFD) && doIncrement 100 && (softfloat_compare128M( 101 extSigPtr + indexMultiwordHi( 5, 4 ), maxSig ) 102 == 0)) 103 ) { 104 /*---------------------------------------------------------------- 105 *----------------------------------------------------------------*/ 106 softfloat_raiseFlags( 107 softfloat_flag_overflow | softfloat_flag_inexact ); 108 if ( 109 roundNearEven 110 || (roundingMode == softfloat_round_near_maxMag) 111 || (roundingMode 112 == (sign ? softfloat_round_min : softfloat_round_max)) 113 ) { 114 ui = packToF128UI96( sign, 0x7FFF, 0 ); 115 uj = 0; 116 } else { 117 ui = packToF128UI96( sign, 0x7FFE, 0x0000FFFF ); 118 uj = 0xFFFFFFFF; 119 } 120 zWPtr[indexWordHi( 4 )] = ui; 121 zWPtr[indexWord( 4, 2 )] = uj; 122 zWPtr[indexWord( 4, 1 )] = uj; 123 zWPtr[indexWord( 4, 0 )] = uj; 124 return; 125 } 126 } 127 /*------------------------------------------------------------------------ 128 *------------------------------------------------------------------------*/ 129 uj = extSigPtr[indexWord( 5, 1 )]; 130 if ( sigExtra ) { 131 softfloat_raiseFlags( softfloat_flag_inexact ); 132#ifdef SOFTFLOAT_ROUND_ODD 133 if ( roundingMode == softfloat_round_odd ) { 134 uj |= 1; 135 goto noIncrementPackReturn; 136 } 137#endif 138 } 139 if ( doIncrement ) { 140 ++uj; 141 if ( uj ) { 142 if ( ! (sigExtra & 0x7FFFFFFF) && roundNearEven ) uj &= ~1; 143 zWPtr[indexWord( 4, 2 )] = extSigPtr[indexWord( 5, 3 )]; 144 zWPtr[indexWord( 4, 1 )] = extSigPtr[indexWord( 5, 2 )]; 145 zWPtr[indexWord( 4, 0 )] = uj; 146 ui = extSigPtr[indexWordHi( 5 )]; 147 } else { 148 zWPtr[indexWord( 4, 0 )] = uj; 149 ui = extSigPtr[indexWord( 5, 2 )] + 1; 150 zWPtr[indexWord( 4, 1 )] = ui; 151 uj = extSigPtr[indexWord( 5, 3 )]; 152 if ( ui ) { 153 zWPtr[indexWord( 4, 2 )] = uj; 154 ui = extSigPtr[indexWordHi( 5 )]; 155 } else { 156 ++uj; 157 zWPtr[indexWord( 4, 2 )] = uj; 158 ui = extSigPtr[indexWordHi( 5 )]; 159 if ( ! uj ) ++ui; 160 } 161 } 162 } else { 163 noIncrementPackReturn: 164 zWPtr[indexWord( 4, 0 )] = uj; 165 ui = extSigPtr[indexWord( 5, 2 )]; 166 zWPtr[indexWord( 4, 1 )] = ui; 167 uj |= ui; 168 ui = extSigPtr[indexWord( 5, 3 )]; 169 zWPtr[indexWord( 4, 2 )] = ui; 170 uj |= ui; 171 ui = extSigPtr[indexWordHi( 5 )]; 172 uj |= ui; 173 if ( ! uj ) exp = 0; 174 } 175 zWPtr[indexWordHi( 4 )] = packToF128UI96( sign, exp, ui ); 176 177} 178 179