1 2 /*============================================================================ 3 4 This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic 5 Package, Release 3a, by John R. Hauser. 6 7 Copyright 2011, 2012, 2013, 2014 The Regents of the University of California. 8 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 void 45 softfloat_addExtF80M( 46 const struct extFloat80M *aSPtr, 47 const struct extFloat80M *bSPtr, 48 struct extFloat80M *zSPtr, 49 bool negateB 50 ) 51 { 52 uint32_t uiA64; 53 int32_t expA; 54 uint32_t uiB64; 55 int32_t expB; 56 uint32_t uiZ64; 57 bool signZ, signB; 58 const struct extFloat80M *tempSPtr; 59 uint64_t sigZ, sigB; 60 void 61 (*roundPackRoutinePtr)( 62 bool, int32_t, uint32_t *, uint_fast8_t, struct extFloat80M * ); 63 int32_t expDiff; 64 uint32_t extSigX[3], sigZExtra; 65 66 /*------------------------------------------------------------------------ 67 *------------------------------------------------------------------------*/ 68 uiA64 = aSPtr->signExp; 69 expA = expExtF80UI64( uiA64 ); 70 uiB64 = bSPtr->signExp; 71 expB = expExtF80UI64( uiB64 ); 72 /*------------------------------------------------------------------------ 73 *------------------------------------------------------------------------*/ 74 if ( (expA == 0x7FFF) || (expB == 0x7FFF) ) { 75 if ( softfloat_tryPropagateNaNExtF80M( aSPtr, bSPtr, zSPtr ) ) return; 76 uiZ64 = uiA64; 77 if ( expB == 0x7FFF ) { 78 uiZ64 = uiB64 ^ packToExtF80UI64( negateB, 0 ); 79 if ( (expA == 0x7FFF) && (uiZ64 != uiA64) ) { 80 softfloat_invalidExtF80M( zSPtr ); 81 return; 82 } 83 } 84 zSPtr->signExp = uiZ64; 85 zSPtr->signif = UINT64_C( 0x8000000000000000 ); 86 return; 87 } 88 /*------------------------------------------------------------------------ 89 *------------------------------------------------------------------------*/ 90 signZ = signExtF80UI64( uiA64 ); 91 signB = signExtF80UI64( uiB64 ) ^ negateB; 92 negateB = (signZ != signB); 93 if ( expA < expB ) { 94 signZ = signB; 95 expA = expB; 96 expB = expExtF80UI64( uiA64 ); 97 tempSPtr = aSPtr; 98 aSPtr = bSPtr; 99 bSPtr = tempSPtr; 100 } 101 if ( ! expB ) { 102 expB = 1; 103 if ( ! expA ) expA = 1; 104 } 105 sigZ = aSPtr->signif; 106 sigB = bSPtr->signif; 107 /*------------------------------------------------------------------------ 108 *------------------------------------------------------------------------*/ 109 roundPackRoutinePtr = softfloat_roundPackMToExtF80M; 110 expDiff = expA - expB; 111 if ( expDiff ) { 112 /*-------------------------------------------------------------------- 113 *--------------------------------------------------------------------*/ 114 extSigX[indexWord( 3, 2 )] = sigB>>32; 115 extSigX[indexWord( 3, 1 )] = sigB; 116 extSigX[indexWord( 3, 0 )] = 0; 117 softfloat_shiftRightJam96M( extSigX, expDiff, extSigX ); 118 sigB = 119 (uint64_t) extSigX[indexWord( 3, 2 )]<<32 120 | extSigX[indexWord( 3, 1 )]; 121 if ( negateB ) { 122 sigZ -= sigB; 123 sigZExtra = extSigX[indexWordLo( 3 )]; 124 if ( sigZExtra ) { 125 --sigZ; 126 sigZExtra = -sigZExtra; 127 } 128 if ( ! (sigZ & UINT64_C( 0x8000000000000000 )) ) { 129 if ( sigZ & UINT64_C( 0x4000000000000000 ) ) { 130 --expA; 131 sigZ = sigZ<<1 | sigZExtra>>31; 132 sigZExtra <<= 1; 133 } else { 134 roundPackRoutinePtr = softfloat_normRoundPackMToExtF80M; 135 } 136 } 137 } else { 138 sigZ += sigB; 139 if ( sigZ & UINT64_C( 0x8000000000000000 ) ) goto sigZ; 140 sigZExtra = (uint32_t) sigZ<<31 | (extSigX[indexWordLo( 3 )] != 0); 141 goto completeNormAfterAdd; 142 } 143 } else { 144 /*-------------------------------------------------------------------- 145 *--------------------------------------------------------------------*/ 146 sigZExtra = 0; 147 if ( negateB ) { 148 if ( sigZ < sigB ) { 149 signZ = ! signZ; 150 sigZ = sigB - sigZ; 151 } else { 152 sigZ -= sigB; 153 if ( ! sigZ ) { 154 signZ = (softfloat_roundingMode == softfloat_round_min); 155 zSPtr->signExp = packToExtF80UI64( signZ, 0 ); 156 zSPtr->signif = 0; 157 return; 158 } 159 } 160 roundPackRoutinePtr = softfloat_normRoundPackMToExtF80M; 161 } else { 162 sigZ += sigB; 163 if ( sigZ < sigB ) { 164 sigZExtra = (uint32_t) sigZ<<31; 165 completeNormAfterAdd: 166 ++expA; 167 sigZ = UINT64_C( 0x8000000000000000 ) | sigZ>>1; 168 } else { 169 if ( ! (sigZ & UINT64_C( 0x8000000000000000 )) ) { 170 roundPackRoutinePtr = softfloat_normRoundPackMToExtF80M; 171 } 172 } 173 } 174 } 175 extSigX[indexWord( 3, 0 )] = sigZExtra; 176 sigZ: 177 extSigX[indexWord( 3, 2 )] = sigZ>>32; 178 extSigX[indexWord( 3, 1 )] = sigZ; 179 /*------------------------------------------------------------------------ 180 *------------------------------------------------------------------------*/ 181 roundPack: 182 (*roundPackRoutinePtr)( 183 signZ, expA, extSigX, extF80_roundingPrecision, zSPtr ); 184 185 } 186 187