1 // SPDX-License-Identifier: BSD-3-Clause 2 3 /*============================================================================ 4 5 This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic 6 Package, Release 3a, by John R. Hauser. 7 8 Copyright 2011, 2012, 2013, 2014 The Regents of the University of California. 9 All rights reserved. 10 11 Redistribution and use in source and binary forms, with or without 12 modification, are permitted provided that the following conditions are met: 13 14 1. Redistributions of source code must retain the above copyright notice, 15 this list of conditions, and the following disclaimer. 16 17 2. Redistributions in binary form must reproduce the above copyright notice, 18 this list of conditions, and the following disclaimer in the documentation 19 and/or other materials provided with the distribution. 20 21 3. Neither the name of the University nor the names of its contributors may 22 be used to endorse or promote products derived from this software without 23 specific prior written permission. 24 25 THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS", AND ANY 26 EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 27 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE 28 DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY 29 DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 30 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 31 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 32 ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 33 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 34 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 35 36 =============================================================================*/ 37 38 #include <stdbool.h> 39 #include <stdint.h> 40 #include "platform.h" 41 #include "internals.h" 42 #include "specialize.h" 43 #include "softfloat.h" 44 45 #ifdef SOFTFLOAT_FAST_INT64 46 47 void f128M_roundToInt(const float128_t * aPtr,uint_fast8_t roundingMode,bool exact,float128_t * zPtr)48 f128M_roundToInt( 49 const float128_t *aPtr, 50 uint_fast8_t roundingMode, 51 bool exact, 52 float128_t *zPtr 53 ) 54 { 55 56 *zPtr = f128_roundToInt( *aPtr, roundingMode, exact ); 57 58 } 59 60 #else 61 62 void f128M_roundToInt(const float128_t * aPtr,uint_fast8_t roundingMode,bool exact,float128_t * zPtr)63 f128M_roundToInt( 64 const float128_t *aPtr, 65 uint_fast8_t roundingMode, 66 bool exact, 67 float128_t *zPtr 68 ) 69 { 70 const uint32_t *aWPtr; 71 uint32_t *zWPtr; 72 uint32_t ui96; 73 int32_t exp; 74 uint32_t sigExtra; 75 bool sign; 76 uint_fast8_t bitPos; 77 bool roundNear; 78 unsigned int index, lastIndex; 79 bool extra; 80 uint32_t wordA, bit, wordZ; 81 uint_fast8_t carry; 82 uint32_t extrasMask; 83 84 /*------------------------------------------------------------------------ 85 *------------------------------------------------------------------------*/ 86 aWPtr = (const uint32_t *) aPtr; 87 zWPtr = (uint32_t *) zPtr; 88 /*------------------------------------------------------------------------ 89 *------------------------------------------------------------------------*/ 90 ui96 = aWPtr[indexWordHi( 4 )]; 91 exp = expF128UI96( ui96 ); 92 /*------------------------------------------------------------------------ 93 *------------------------------------------------------------------------*/ 94 if ( exp < 0x3FFF ) { 95 zWPtr[indexWord( 4, 2 )] = 0; 96 zWPtr[indexWord( 4, 1 )] = 0; 97 zWPtr[indexWord( 4, 0 )] = 0; 98 sigExtra = aWPtr[indexWord( 4, 2 )]; 99 if ( ! sigExtra ) { 100 sigExtra = aWPtr[indexWord( 4, 1 )] | aWPtr[indexWord( 4, 0 )]; 101 } 102 if ( ! sigExtra && ! (ui96 & 0x7FFFFFFF) ) goto ui96; 103 if ( exact ) softfloat_exceptionFlags |= softfloat_flag_inexact; 104 sign = signF128UI96( ui96 ); 105 switch ( roundingMode ) { 106 case softfloat_round_near_even: 107 if ( ! fracF128UI96( ui96 ) && ! sigExtra ) break; 108 case softfloat_round_near_maxMag: 109 if ( exp == 0x3FFE ) goto mag1; 110 break; 111 case softfloat_round_min: 112 if ( sign ) goto mag1; 113 break; 114 case softfloat_round_max: 115 if ( ! sign ) goto mag1; 116 break; 117 } 118 ui96 = packToF128UI96( sign, 0, 0 ); 119 goto ui96; 120 mag1: 121 ui96 = packToF128UI96( sign, 0x3FFF, 0 ); 122 goto ui96; 123 } 124 /*------------------------------------------------------------------------ 125 *------------------------------------------------------------------------*/ 126 if ( 0x406F <= exp ) { 127 if ( 128 (exp == 0x7FFF) 129 && (fracF128UI96( ui96 ) 130 || (aWPtr[indexWord( 4, 2 )] | aWPtr[indexWord( 4, 1 )] 131 | aWPtr[indexWord( 4, 0 )])) 132 ) { 133 softfloat_propagateNaNF128M( aWPtr, 0, zWPtr ); 134 return; 135 } 136 zWPtr[indexWord( 4, 2 )] = aWPtr[indexWord( 4, 2 )]; 137 zWPtr[indexWord( 4, 1 )] = aWPtr[indexWord( 4, 1 )]; 138 zWPtr[indexWord( 4, 0 )] = aWPtr[indexWord( 4, 0 )]; 139 goto ui96; 140 } 141 /*------------------------------------------------------------------------ 142 *------------------------------------------------------------------------*/ 143 bitPos = 0x406F - exp; 144 roundNear = 145 (roundingMode == softfloat_round_near_maxMag) 146 || (roundingMode == softfloat_round_near_even); 147 bitPos -= roundNear; 148 index = indexWordLo( 4 ); 149 lastIndex = indexWordHi( 4 ); 150 extra = 0; 151 for (;;) { 152 wordA = aWPtr[index]; 153 if ( bitPos < 32 ) break; 154 if ( wordA ) extra = 1; 155 zWPtr[index] = 0; 156 index += wordIncr; 157 bitPos -= 32; 158 } 159 bit = (uint32_t) 1<<bitPos; 160 if ( roundNear ) { 161 wordZ = wordA + bit; 162 carry = (wordZ < wordA); 163 bit <<= 1; 164 extrasMask = bit - 1; 165 if ( 166 (roundingMode == softfloat_round_near_even) 167 && ! extra && ! (wordZ & extrasMask) 168 ) { 169 if ( ! bit ) { 170 zWPtr[index] = wordZ; 171 index += wordIncr; 172 wordZ = aWPtr[index] + carry; 173 carry &= ! wordZ; 174 zWPtr[index] = wordZ & ~1; 175 goto propagateCarry; 176 } 177 wordZ &= ~bit; 178 } 179 } else { 180 extrasMask = bit - 1; 181 wordZ = wordA; 182 carry = 0; 183 if ( 184 (roundingMode != softfloat_round_minMag) 185 && (signF128UI96( ui96 ) ^ (roundingMode == softfloat_round_max)) 186 ) { 187 if ( extra || (wordA & extrasMask) ) { 188 wordZ += bit; 189 carry = (wordZ < wordA); 190 } 191 } 192 } 193 wordZ &= ~extrasMask; 194 zWPtr[index] = wordZ; 195 propagateCarry: 196 while ( index != lastIndex ) { 197 index += wordIncr; 198 wordZ = aWPtr[index] + carry; 199 zWPtr[index] = wordZ; 200 carry &= ! wordZ; 201 } 202 /*------------------------------------------------------------------------ 203 *------------------------------------------------------------------------*/ 204 if ( exact && (softfloat_compare128M( aWPtr, zWPtr ) != 0) ) { 205 softfloat_exceptionFlags |= softfloat_flag_inexact; 206 } 207 return; 208 /*------------------------------------------------------------------------ 209 *------------------------------------------------------------------------*/ 210 ui96: 211 zWPtr[indexWordHi( 4 )] = ui96; 212 213 } 214 215 #endif 216 217