1 2 /*============================================================================ 3 4 This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic 5 Package, Release 3e, by John R. Hauser. 6 7 Copyright 2011, 2012, 2013, 2014, 2015, 2016 The Regents of the University of 8 California. 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 extF80M_div(const extFloat80_t * aPtr,const extFloat80_t * bPtr,extFloat80_t * zPtr)47 extF80M_div( 48 const extFloat80_t *aPtr, const extFloat80_t *bPtr, extFloat80_t *zPtr ) 49 { 50 51 *zPtr = extF80_div( *aPtr, *bPtr ); 52 53 } 54 55 #else 56 57 void extF80M_div(const extFloat80_t * aPtr,const extFloat80_t * bPtr,extFloat80_t * zPtr)58 extF80M_div( 59 const extFloat80_t *aPtr, const extFloat80_t *bPtr, extFloat80_t *zPtr ) 60 { 61 const struct extFloat80M *aSPtr, *bSPtr; 62 struct extFloat80M *zSPtr; 63 uint_fast16_t uiA64; 64 int32_t expA; 65 uint_fast16_t uiB64; 66 int32_t expB; 67 bool signZ; 68 uint64_t sigA, x64; 69 int32_t expZ; 70 int shiftDist; 71 uint32_t y[3], recip32, sigB[3]; 72 int ix; 73 uint32_t q, qs[2]; 74 uint_fast16_t uiZ64; 75 uint64_t uiZ0; 76 77 /*------------------------------------------------------------------------ 78 *------------------------------------------------------------------------*/ 79 aSPtr = (const struct extFloat80M *) aPtr; 80 bSPtr = (const struct extFloat80M *) bPtr; 81 zSPtr = (struct extFloat80M *) zPtr; 82 /*------------------------------------------------------------------------ 83 *------------------------------------------------------------------------*/ 84 uiA64 = aSPtr->signExp; 85 expA = expExtF80UI64( uiA64 ); 86 uiB64 = bSPtr->signExp; 87 expB = expExtF80UI64( uiB64 ); 88 signZ = signExtF80UI64( uiA64 ) ^ signExtF80UI64( uiB64 ); 89 /*------------------------------------------------------------------------ 90 *------------------------------------------------------------------------*/ 91 if ( (expA == 0x7FFF) || (expB == 0x7FFF) ) { 92 if ( softfloat_tryPropagateNaNExtF80M( aSPtr, bSPtr, zSPtr ) ) return; 93 if ( expA == 0x7FFF ) { 94 if ( expB == 0x7FFF ) goto invalid; 95 goto infinity; 96 } 97 goto zero; 98 } 99 /*------------------------------------------------------------------------ 100 *------------------------------------------------------------------------*/ 101 sigA = aSPtr->signif; 102 x64 = bSPtr->signif; 103 if ( ! expB ) expB = 1; 104 if ( ! (x64 & UINT64_C( 0x8000000000000000 )) ) { 105 if ( ! x64 ) { 106 if ( ! sigA ) goto invalid; 107 softfloat_raiseFlags( softfloat_flag_infinite ); 108 goto infinity; 109 } 110 expB += softfloat_normExtF80SigM( &x64 ); 111 } 112 if ( ! expA ) expA = 1; 113 if ( ! (sigA & UINT64_C( 0x8000000000000000 )) ) { 114 if ( ! sigA ) goto zero; 115 expA += softfloat_normExtF80SigM( &sigA ); 116 } 117 /*------------------------------------------------------------------------ 118 *------------------------------------------------------------------------*/ 119 expZ = expA - expB + 0x3FFF; 120 shiftDist = 29; 121 if ( sigA < x64 ) { 122 --expZ; 123 shiftDist = 30; 124 } 125 softfloat_shortShiftLeft64To96M( sigA, shiftDist, y ); 126 recip32 = softfloat_approxRecip32_1( x64>>32 ); 127 sigB[indexWord( 3, 0 )] = (uint32_t) x64<<30; 128 x64 >>= 2; 129 sigB[indexWord( 3, 2 )] = x64>>32; 130 sigB[indexWord( 3, 1 )] = x64; 131 ix = 2; 132 for (;;) { 133 x64 = (uint64_t) y[indexWordHi( 3 )] * recip32; 134 q = (x64 + 0x80000000)>>32; 135 --ix; 136 if ( ix < 0 ) break; 137 softfloat_remStep96MBy32( y, 29, sigB, q, y ); 138 if ( y[indexWordHi( 3 )] & 0x80000000 ) { 139 --q; 140 softfloat_add96M( y, sigB, y ); 141 } 142 qs[ix] = q; 143 } 144 /*------------------------------------------------------------------------ 145 *------------------------------------------------------------------------*/ 146 if ( ((q + 1) & 0x3FFFFF) < 2 ) { 147 softfloat_remStep96MBy32( y, 29, sigB, q, y ); 148 if ( y[indexWordHi( 3 )] & 0x80000000 ) { 149 --q; 150 softfloat_add96M( y, sigB, y ); 151 } else if ( softfloat_compare96M( sigB, y ) <= 0 ) { 152 ++q; 153 softfloat_sub96M( y, sigB, y ); 154 } 155 if ( 156 y[indexWordLo( 3 )] || y[indexWord( 3, 1 )] || y[indexWord( 3, 2 )] 157 ) { 158 q |= 1; 159 } 160 } 161 /*------------------------------------------------------------------------ 162 *------------------------------------------------------------------------*/ 163 x64 = (uint64_t) q<<9; 164 y[indexWord( 3, 0 )] = x64; 165 x64 = ((uint64_t) qs[0]<<6) + (x64>>32); 166 y[indexWord( 3, 1 )] = x64; 167 y[indexWord( 3, 2 )] = (qs[1]<<3) + (x64>>32); 168 softfloat_roundPackMToExtF80M( 169 signZ, expZ, y, extF80_roundingPrecision, zSPtr ); 170 return; 171 /*------------------------------------------------------------------------ 172 *------------------------------------------------------------------------*/ 173 invalid: 174 softfloat_invalidExtF80M( zSPtr ); 175 return; 176 /*------------------------------------------------------------------------ 177 *------------------------------------------------------------------------*/ 178 infinity: 179 uiZ64 = packToExtF80UI64( signZ, 0x7FFF ); 180 uiZ0 = UINT64_C( 0x8000000000000000 ); 181 goto uiZ; 182 /*------------------------------------------------------------------------ 183 *------------------------------------------------------------------------*/ 184 zero: 185 uiZ64 = packToExtF80UI64( signZ, 0 ); 186 uiZ0 = 0; 187 uiZ: 188 zSPtr->signExp = uiZ64; 189 zSPtr->signif = uiZ0; 190 191 } 192 193 #endif 194 195