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_rem(const float128_t * aPtr,const float128_t * bPtr,float128_t * zPtr)48 f128M_rem( const float128_t *aPtr, const float128_t *bPtr, float128_t *zPtr ) 49 { 50 51 *zPtr = f128_rem( *aPtr, *bPtr ); 52 53 } 54 55 #else 56 57 void f128M_rem(const float128_t * aPtr,const float128_t * bPtr,float128_t * zPtr)58 f128M_rem( const float128_t *aPtr, const float128_t *bPtr, float128_t *zPtr ) 59 { 60 const uint32_t *aWPtr, *bWPtr; 61 uint32_t *zWPtr, uiA96; 62 int32_t expA, expB; 63 uint32_t x[4], rem1[5], *remPtr; 64 bool signRem; 65 int32_t expDiff; 66 uint32_t q, recip32; 67 uint64_t q64; 68 uint32_t rem2[5], *altRemPtr, *newRemPtr, wordMeanRem; 69 70 /*------------------------------------------------------------------------ 71 *------------------------------------------------------------------------*/ 72 aWPtr = (const uint32_t *) aPtr; 73 bWPtr = (const uint32_t *) bPtr; 74 zWPtr = (uint32_t *) zPtr; 75 /*------------------------------------------------------------------------ 76 *------------------------------------------------------------------------*/ 77 uiA96 = aWPtr[indexWordHi( 4 )]; 78 expA = expF128UI96( uiA96 ); 79 expB = expF128UI96( bWPtr[indexWordHi( 4 )] ); 80 /*------------------------------------------------------------------------ 81 *------------------------------------------------------------------------*/ 82 if ( (expA == 0x7FFF) || (expB == 0x7FFF) ) { 83 if ( softfloat_tryPropagateNaNF128M( aWPtr, bWPtr, zWPtr ) ) return; 84 if ( expA == 0x7FFF ) goto invalid; 85 goto copyA; 86 } 87 /*------------------------------------------------------------------------ 88 *------------------------------------------------------------------------*/ 89 if ( expA < expB - 1 ) goto copyA; 90 /*------------------------------------------------------------------------ 91 *------------------------------------------------------------------------*/ 92 expB = softfloat_shiftNormSigF128M( bWPtr, 13, x ); 93 if ( expB == -128 ) goto invalid; 94 remPtr = &rem1[indexMultiwordLo( 5, 4 )]; 95 expA = softfloat_shiftNormSigF128M( aWPtr, 13, remPtr ); 96 if ( expA == -128 ) goto copyA; 97 signRem = signF128UI96( uiA96 ); 98 /*------------------------------------------------------------------------ 99 *------------------------------------------------------------------------*/ 100 expDiff = expA - expB; 101 if ( expDiff < 1 ) { 102 if ( expDiff < -1 ) goto copyA; 103 if ( expDiff ) { 104 --expB; 105 softfloat_add128M( x, x, x ); 106 q = 0; 107 } else { 108 q = (softfloat_compare128M( x, remPtr ) <= 0); 109 if ( q ) softfloat_sub128M( remPtr, x, remPtr ); 110 } 111 } else { 112 recip32 = 113 softfloat_approxRecip32_1( 114 ((uint64_t) x[indexWord( 4, 3 )]<<32 | x[indexWord( 4, 2 )]) 115 >>30 116 ); 117 expDiff -= 30; 118 for (;;) { 119 q64 = (uint64_t) remPtr[indexWordHi( 4 )] * recip32; 120 if ( expDiff < 0 ) break; 121 q = (q64 + 0x80000000)>>32; 122 softfloat_remStep128MBy32( remPtr, 29, x, q, remPtr ); 123 if ( remPtr[indexWordHi( 4 )] & 0x80000000 ) { 124 softfloat_add128M( remPtr, x, remPtr ); 125 } 126 expDiff -= 29; 127 } 128 /*-------------------------------------------------------------------- 129 | (`expDiff' cannot be less than -29 here.) 130 *--------------------------------------------------------------------*/ 131 q = (uint32_t) (q64>>32)>>(~expDiff & 31); 132 softfloat_remStep128MBy32( remPtr, expDiff + 30, x, q, remPtr ); 133 if ( remPtr[indexWordHi( 4 )] & 0x80000000 ) { 134 altRemPtr = &rem2[indexMultiwordLo( 5, 4 )]; 135 softfloat_add128M( remPtr, x, altRemPtr ); 136 goto selectRem; 137 } 138 } 139 /*------------------------------------------------------------------------ 140 *------------------------------------------------------------------------*/ 141 altRemPtr = &rem2[indexMultiwordLo( 5, 4 )]; 142 do { 143 ++q; 144 newRemPtr = altRemPtr; 145 softfloat_sub128M( remPtr, x, newRemPtr ); 146 altRemPtr = remPtr; 147 remPtr = newRemPtr; 148 } while ( ! (remPtr[indexWordHi( 4 )] & 0x80000000) ); 149 selectRem: 150 softfloat_add128M( remPtr, altRemPtr, x ); 151 wordMeanRem = x[indexWordHi( 4 )]; 152 if ( 153 (wordMeanRem & 0x80000000) 154 || (! wordMeanRem && (q & 1) && ! x[indexWord( 4, 0 )] 155 && ! (x[indexWord( 4, 2 )] | x[indexWord( 4, 1 )])) 156 ) { 157 remPtr = altRemPtr; 158 } 159 if ( remPtr[indexWordHi( 4 )] & 0x80000000 ) { 160 signRem = ! signRem; 161 softfloat_negX128M( remPtr ); 162 } 163 remPtr -= indexMultiwordLo( 5, 4 ); 164 remPtr[indexWordHi( 5 )] = 0; 165 softfloat_normRoundPackMToF128M( signRem, expB + 18, remPtr, zWPtr ); 166 return; 167 /*------------------------------------------------------------------------ 168 *------------------------------------------------------------------------*/ 169 invalid: 170 softfloat_invalidF128M( zWPtr ); 171 return; 172 /*------------------------------------------------------------------------ 173 *------------------------------------------------------------------------*/ 174 copyA: 175 zWPtr[indexWordHi( 4 )] = uiA96; 176 zWPtr[indexWord( 4, 2 )] = aWPtr[indexWord( 4, 2 )]; 177 zWPtr[indexWord( 4, 1 )] = aWPtr[indexWord( 4, 1 )]; 178 zWPtr[indexWord( 4, 0 )] = aWPtr[indexWord( 4, 0 )]; 179 180 } 181 182 #endif 183 184