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 extFloat80_t softfloat_addMagsExtF80(uint_fast16_t uiA64,uint_fast64_t uiA0,uint_fast16_t uiB64,uint_fast64_t uiB0,bool signZ)46 softfloat_addMagsExtF80( 47 uint_fast16_t uiA64, 48 uint_fast64_t uiA0, 49 uint_fast16_t uiB64, 50 uint_fast64_t uiB0, 51 bool signZ 52 ) 53 { 54 int_fast32_t expA; 55 uint_fast64_t sigA; 56 int_fast32_t expB; 57 uint_fast64_t sigB; 58 int_fast32_t expDiff; 59 uint_fast16_t uiZ64; 60 uint_fast64_t uiZ0, sigZ, sigZExtra; 61 struct exp32_sig64 normExpSig; 62 int_fast32_t expZ; 63 struct uint64_extra sig64Extra; 64 struct uint128 uiZ; 65 union { struct extFloat80M s; extFloat80_t f; } uZ; 66 67 /*------------------------------------------------------------------------ 68 *------------------------------------------------------------------------*/ 69 expA = expExtF80UI64( uiA64 ); 70 sigA = uiA0; 71 expB = expExtF80UI64( uiB64 ); 72 sigB = uiB0; 73 /*------------------------------------------------------------------------ 74 *------------------------------------------------------------------------*/ 75 expDiff = expA - expB; 76 if ( ! expDiff ) { 77 if ( expA == 0x7FFF ) { 78 if ( (sigA | sigB) & UINT64_C( 0x7FFFFFFFFFFFFFFF ) ) { 79 goto propagateNaN; 80 } 81 uiZ64 = uiA64; 82 uiZ0 = uiA0; 83 goto uiZ; 84 } 85 sigZ = sigA + sigB; 86 sigZExtra = 0; 87 if ( ! expA ) { 88 normExpSig = softfloat_normSubnormalExtF80Sig( sigZ ); 89 expZ = normExpSig.exp + 1; 90 sigZ = normExpSig.sig; 91 goto roundAndPack; 92 } 93 expZ = expA; 94 goto shiftRight1; 95 } 96 /*------------------------------------------------------------------------ 97 *------------------------------------------------------------------------*/ 98 if ( expDiff < 0 ) { 99 if ( expB == 0x7FFF ) { 100 if ( sigB & UINT64_C( 0x7FFFFFFFFFFFFFFF ) ) goto propagateNaN; 101 uiZ64 = packToExtF80UI64( signZ, 0x7FFF ); 102 uiZ0 = uiB0; 103 goto uiZ; 104 } 105 expZ = expB; 106 if ( ! expA ) { 107 ++expDiff; 108 sigZExtra = 0; 109 if ( ! expDiff ) goto newlyAligned; 110 } 111 sig64Extra = softfloat_shiftRightJam64Extra( sigA, 0, -expDiff ); 112 sigA = sig64Extra.v; 113 sigZExtra = sig64Extra.extra; 114 } else { 115 if ( expA == 0x7FFF ) { 116 if ( sigA & UINT64_C( 0x7FFFFFFFFFFFFFFF ) ) goto propagateNaN; 117 uiZ64 = uiA64; 118 uiZ0 = uiA0; 119 goto uiZ; 120 } 121 expZ = expA; 122 if ( ! expB ) { 123 --expDiff; 124 sigZExtra = 0; 125 if ( ! expDiff ) goto newlyAligned; 126 } 127 sig64Extra = softfloat_shiftRightJam64Extra( sigB, 0, expDiff ); 128 sigB = sig64Extra.v; 129 sigZExtra = sig64Extra.extra; 130 } 131 newlyAligned: 132 sigZ = sigA + sigB; 133 if ( sigZ & UINT64_C( 0x8000000000000000 ) ) goto roundAndPack; 134 /*------------------------------------------------------------------------ 135 *------------------------------------------------------------------------*/ 136 shiftRight1: 137 sig64Extra = softfloat_shortShiftRightJam64Extra( sigZ, sigZExtra, 1 ); 138 sigZ = sig64Extra.v | UINT64_C( 0x8000000000000000 ); 139 sigZExtra = sig64Extra.extra; 140 ++expZ; 141 roundAndPack: 142 return 143 softfloat_roundPackToExtF80( 144 signZ, expZ, sigZ, sigZExtra, extF80_roundingPrecision ); 145 /*------------------------------------------------------------------------ 146 *------------------------------------------------------------------------*/ 147 propagateNaN: 148 uiZ = softfloat_propagateNaNExtF80UI( uiA64, uiA0, uiB64, uiB0 ); 149 uiZ64 = uiZ.v64; 150 uiZ0 = uiZ.v0; 151 uiZ: 152 uZ.s.signExp = uiZ64; 153 uZ.s.signif = uiZ0; 154 return uZ.f; 155 156 } 157 158