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 extFloat80_t 45 softfloat_addMagsExtF80( 46 uint_fast16_t uiA64, 47 uint_fast64_t uiA0, 48 uint_fast16_t uiB64, 49 uint_fast64_t uiB0, 50 bool signZ 51 ) 52 { 53 int_fast32_t expA; 54 uint_fast64_t sigA; 55 int_fast32_t expB; 56 uint_fast64_t sigB; 57 int_fast32_t expDiff; 58 uint_fast16_t uiZ64; 59 uint_fast64_t uiZ0, sigZ, sigZExtra; 60 struct exp32_sig64 normExpSig; 61 int_fast32_t expZ; 62 struct uint64_extra sig64Extra; 63 struct uint128 uiZ; 64 union { struct extFloat80M s; extFloat80_t f; } uZ; 65 66 /*------------------------------------------------------------------------ 67 *------------------------------------------------------------------------*/ 68 expA = expExtF80UI64( uiA64 ); 69 sigA = uiA0; 70 expB = expExtF80UI64( uiB64 ); 71 sigB = uiB0; 72 /*------------------------------------------------------------------------ 73 *------------------------------------------------------------------------*/ 74 expDiff = expA - expB; 75 if ( ! expDiff ) { 76 if ( expA == 0x7FFF ) { 77 if ( (sigA | sigB) & UINT64_C( 0x7FFFFFFFFFFFFFFF ) ) { 78 goto propagateNaN; 79 } 80 uiZ64 = uiA64; 81 uiZ0 = uiA0; 82 goto uiZ; 83 } 84 sigZ = sigA + sigB; 85 sigZExtra = 0; 86 if ( ! expA ) { 87 normExpSig = softfloat_normSubnormalExtF80Sig( sigZ ); 88 expZ = normExpSig.exp + 1; 89 sigZ = normExpSig.sig; 90 goto roundAndPack; 91 } 92 expZ = expA; 93 goto shiftRight1; 94 } 95 /*------------------------------------------------------------------------ 96 *------------------------------------------------------------------------*/ 97 if ( expDiff < 0 ) { 98 if ( expB == 0x7FFF ) { 99 if ( sigB & UINT64_C( 0x7FFFFFFFFFFFFFFF ) ) goto propagateNaN; 100 uiZ64 = packToExtF80UI64( signZ, 0x7FFF ); 101 uiZ0 = uiB0; 102 goto uiZ; 103 } 104 expZ = expB; 105 if ( ! expA ) { 106 ++expDiff; 107 sigZExtra = 0; 108 if ( ! expDiff ) goto newlyAligned; 109 } 110 sig64Extra = softfloat_shiftRightJam64Extra( sigA, 0, -expDiff ); 111 sigA = sig64Extra.v; 112 sigZExtra = sig64Extra.extra; 113 } else { 114 if ( expA == 0x7FFF ) { 115 if ( sigA & UINT64_C( 0x7FFFFFFFFFFFFFFF ) ) goto propagateNaN; 116 uiZ64 = uiA64; 117 uiZ0 = uiA0; 118 goto uiZ; 119 } 120 expZ = expA; 121 if ( ! expB ) { 122 --expDiff; 123 sigZExtra = 0; 124 if ( ! expDiff ) goto newlyAligned; 125 } 126 sig64Extra = softfloat_shiftRightJam64Extra( sigB, 0, expDiff ); 127 sigB = sig64Extra.v; 128 sigZExtra = sig64Extra.extra; 129 } 130 newlyAligned: 131 sigZ = sigA + sigB; 132 if ( sigZ & UINT64_C( 0x8000000000000000 ) ) goto roundAndPack; 133 /*------------------------------------------------------------------------ 134 *------------------------------------------------------------------------*/ 135 shiftRight1: 136 sig64Extra = softfloat_shortShiftRightJam64Extra( sigZ, sigZExtra, 1 ); 137 sigZ = sig64Extra.v | UINT64_C( 0x8000000000000000 ); 138 sigZExtra = sig64Extra.extra; 139 ++expZ; 140 roundAndPack: 141 return 142 softfloat_roundPackToExtF80( 143 signZ, expZ, sigZ, sigZExtra, extF80_roundingPrecision ); 144 /*------------------------------------------------------------------------ 145 *------------------------------------------------------------------------*/ 146 propagateNaN: 147 uiZ = softfloat_propagateNaNExtF80UI( uiA64, uiA0, uiB64, uiB0 ); 148 uiZ64 = uiZ.v64; 149 uiZ0 = uiZ.v0; 150 uiZ: 151 uZ.s.signExp = uiZ64; 152 uZ.s.signif = uiZ0; 153 return uZ.f; 154 155 } 156 157