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Diffstat (limited to 'source/s_mulAddF32.c')
| -rw-r--r-- | source/s_mulAddF32.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/source/s_mulAddF32.c b/source/s_mulAddF32.c new file mode 100644 index 0000000..01d6fb1 --- /dev/null +++ b/source/s_mulAddF32.c @@ -0,0 +1,201 @@ + +/*============================================================================ + +This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic +Package, Release 3, by John R. Hauser. + +Copyright 2011, 2012, 2013, 2014 The Regents of the University of California +(Regents). All Rights Reserved. Redistribution and use in source and binary +forms, with or without modification, are permitted provided that the following +conditions are met: + +Redistributions of source code must retain the above copyright notice, +this list of conditions, and the following two paragraphs of disclaimer. +Redistributions in binary form must reproduce the above copyright notice, +this list of conditions, and the following two paragraphs of disclaimer in the +documentation and/or other materials provided with the distribution. Neither +the name of the Regents nor the names of its contributors may be used to +endorse or promote products derived from this software without specific prior +written permission. + +IN NO EVENT SHALL REGENTS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, +SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING +OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF REGENTS HAS +BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +REGENTS SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED +TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR +PURPOSE. THE SOFTWARE AND ACCOMPANYING DOCUMENTATION, IF ANY, PROVIDED +HEREUNDER IS PROVIDED "AS IS". REGENTS HAS NO OBLIGATION TO PROVIDE +MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. + +=============================================================================*/ + +#include <stdbool.h> +#include <stdint.h> +#include "platform.h" +#include "internals.h" +#include "specialize.h" +#include "softfloat.h" + +float32_t + softfloat_mulAddF32( + uint_fast32_t uiA, uint_fast32_t uiB, uint_fast32_t uiC, uint_fast8_t op ) +{ + bool signA; + int_fast16_t expA; + uint_fast32_t sigA; + bool signB; + int_fast16_t expB; + uint_fast32_t sigB; + bool signC; + int_fast16_t expC; + uint_fast32_t sigC; + bool signProd; + uint_fast32_t magBits, uiZ; + struct exp16_sig32 normExpSig; + int_fast16_t expProd; + uint_fast64_t sigProd; + bool signZ; + int_fast16_t expZ; + uint_fast32_t sigZ; + int_fast16_t expDiff; + uint_fast64_t sig64Z, sig64C; + int_fast8_t shiftCount; + union ui32_f32 uZ; + + signA = signF32UI( uiA ); + expA = expF32UI( uiA ); + sigA = fracF32UI( uiA ); + signB = signF32UI( uiB ); + expB = expF32UI( uiB ); + sigB = fracF32UI( uiB ); + signC = signF32UI( uiC ) ^ (op == softfloat_mulAdd_subC); + expC = expF32UI( uiC ); + sigC = fracF32UI( uiC ); + signProd = signA ^ signB ^ (op == softfloat_mulAdd_subProd); + if ( expA == 0xFF ) { + if ( sigA || ((expB == 0xFF) && sigB) ) goto propagateNaN_ABC; + magBits = expB | sigB; + goto infProdArg; + } + if ( expB == 0xFF ) { + if ( sigB ) goto propagateNaN_ABC; + magBits = expA | sigA; + goto infProdArg; + } + if ( expC == 0xFF ) { + if ( sigC ) { + uiZ = 0; + goto propagateNaN_ZC; + } + uiZ = uiC; + goto uiZ; + } + if ( ! expA ) { + if ( ! sigA ) goto zeroProd; + normExpSig = softfloat_normSubnormalF32Sig( sigA ); + expA = normExpSig.exp; + sigA = normExpSig.sig; + } + if ( ! expB ) { + if ( ! sigB ) goto zeroProd; + normExpSig = softfloat_normSubnormalF32Sig( sigB ); + expB = normExpSig.exp; + sigB = normExpSig.sig; + } + expProd = expA + expB - 0x7E; + sigA = (sigA | 0x00800000)<<7; + sigB = (sigB | 0x00800000)<<7; + sigProd = (uint_fast64_t) sigA * sigB; + if ( sigProd < UINT64_C( 0x2000000000000000 ) ) { + --expProd; + sigProd <<= 1; + } + signZ = signProd; + if ( ! expC ) { + if ( ! sigC ) { + expZ = expProd - 1; + sigZ = softfloat_shortShiftRightJam64( sigProd, 31 ); + goto roundPack; + } + normExpSig = softfloat_normSubnormalF32Sig( sigC ); + expC = normExpSig.exp; + sigC = normExpSig.sig; + } + sigC = (sigC | 0x00800000)<<6; + expDiff = expProd - expC; + if ( signProd == signC ) { + if ( expDiff <= 0 ) { + expZ = expC; + sigZ = sigC + softfloat_shiftRightJam64( sigProd, 32 - expDiff ); + } else { + expZ = expProd; + sig64Z = + sigProd + + softfloat_shiftRightJam64( + (uint_fast64_t) sigC<<32, expDiff ); + sigZ = softfloat_shortShiftRightJam64( sig64Z, 32 ); + } + if ( sigZ < 0x40000000 ) { + --expZ; + sigZ <<= 1; + } + } else { + sig64C = (uint_fast64_t) sigC<<32; + if ( expDiff < 0 ) { + signZ = signC; + expZ = expC; + sig64Z = sig64C - softfloat_shiftRightJam64( sigProd, -expDiff ); + } else if ( ! expDiff ) { + expZ = expProd; + sig64Z = sigProd - sig64C; + if ( ! sig64Z ) goto completeCancellation; + if ( sig64Z & UINT64_C( 0x8000000000000000 ) ) { + signZ ^= 1; + sig64Z = -sig64Z; + } + } else { + expZ = expProd; + sig64Z = sigProd - softfloat_shiftRightJam64( sig64C, expDiff ); + } + shiftCount = softfloat_countLeadingZeros64( sig64Z ) - 1; + expZ -= shiftCount; + shiftCount -= 32; + if ( shiftCount < 0 ) { + sigZ = softfloat_shortShiftRightJam64( sig64Z, -shiftCount ); + } else { + sigZ = (uint_fast32_t) sig64Z<<shiftCount; + } + } + roundPack: + return softfloat_roundPackToF32( signZ, expZ, sigZ ); + propagateNaN_ABC: + uiZ = softfloat_propagateNaNF32UI( uiA, uiB ); + goto propagateNaN_ZC; + infProdArg: + if ( magBits ) { + uiZ = packToF32UI( signProd, 0xFF, 0 ); + if ( expC != 0xFF ) goto uiZ; + if ( sigC ) goto propagateNaN_ZC; + if ( signProd == signC ) goto uiZ; + } + invalid: + softfloat_raiseFlags( softfloat_flag_invalid ); + uiZ = defaultNaNF32UI; + propagateNaN_ZC: + uiZ = softfloat_propagateNaNF32UI( uiZ, uiC ); + goto uiZ; + zeroProd: + uiZ = uiC; + if ( ! (expC | sigC) && (signProd != signC) ) { + completeCancellation: + uiZ = + packToF32UI( softfloat_roundingMode == softfloat_round_min, 0, 0 ); + } + uiZ: + uZ.ui = uiZ; + return uZ.f; + +} + |