Eyck Jentzsch
dcaf5467e8
(http://www.jhauser.us/arithmetic/SoftFloat.html) with RISCV specialization and cmake build
383 lines
15 KiB
C
383 lines
15 KiB
C
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/*============================================================================
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This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
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Package, Release 3e, by John R. Hauser.
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Copyright 2011, 2012, 2013, 2014, 2015, 2016 The Regents of the University of
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California. All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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1. Redistributions of source code must retain the above copyright notice,
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this list of conditions, and the following disclaimer.
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2. Redistributions in binary form must reproduce the above copyright notice,
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this list of conditions, and the following disclaimer in the documentation
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and/or other materials provided with the distribution.
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3. Neither the name of the University nor the names of its contributors may
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be used to endorse or promote products derived from this software without
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specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS", AND ANY
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EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE
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DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
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DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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=============================================================================*/
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#include <stdbool.h>
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#include <stdint.h>
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#include "platform.h"
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#include "internals.h"
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#include "specialize.h"
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#include "softfloat.h"
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void
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softfloat_mulAddF128M(
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const uint32_t *aWPtr,
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const uint32_t *bWPtr,
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const uint32_t *cWPtr,
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uint32_t *zWPtr,
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uint_fast8_t op
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)
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{
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uint32_t uiA96;
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int32_t expA;
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uint32_t uiB96;
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int32_t expB;
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uint32_t uiC96;
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bool signC;
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int32_t expC;
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bool signProd, prodIsInfinite;
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uint32_t *ptr, uiZ96, sigA[4];
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uint_fast8_t shiftDist;
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uint32_t sigX[5];
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int32_t expProd;
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uint32_t sigProd[8], wordSig;
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bool doSub;
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uint_fast8_t
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(*addCarryMRoutinePtr)(
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uint_fast8_t,
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const uint32_t *,
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const uint32_t *,
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uint_fast8_t,
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uint32_t *
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);
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int32_t expDiff;
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bool signZ;
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int32_t expZ;
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uint32_t *extSigPtr;
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uint_fast8_t carry;
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void (*roundPackRoutinePtr)( bool, int32_t, uint32_t *, uint32_t * );
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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uiA96 = aWPtr[indexWordHi( 4 )];
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expA = expF128UI96( uiA96 );
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uiB96 = bWPtr[indexWordHi( 4 )];
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expB = expF128UI96( uiB96 );
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uiC96 = cWPtr[indexWordHi( 4 )];
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signC = signF128UI96( uiC96 ) ^ (op == softfloat_mulAdd_subC);
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expC = expF128UI96( uiC96 );
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signProd =
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signF128UI96( uiA96 ) ^ signF128UI96( uiB96 )
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^ (op == softfloat_mulAdd_subProd);
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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prodIsInfinite = false;
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if ( (expA == 0x7FFF) || (expB == 0x7FFF) ) {
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if ( softfloat_tryPropagateNaNF128M( aWPtr, bWPtr, zWPtr ) ) {
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goto propagateNaN_ZC;
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}
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ptr = (uint32_t *) aWPtr;
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if ( ! (uint32_t) (uiA96<<1) ) goto possibleInvalidProd;
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if ( ! (uint32_t) (uiB96<<1) ) {
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ptr = (uint32_t *) bWPtr;
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possibleInvalidProd:
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if (
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! (ptr[indexWord( 4, 2 )] | ptr[indexWord( 4, 1 )]
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| ptr[indexWord( 4, 0 )])
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) {
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goto invalid;
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}
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}
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prodIsInfinite = true;
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}
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if ( expC == 0x7FFF ) {
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if (
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fracF128UI96( uiC96 )
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|| (cWPtr[indexWord( 4, 2 )] | cWPtr[indexWord( 4, 1 )]
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| cWPtr[indexWord( 4, 0 )])
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) {
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zWPtr[indexWordHi( 4 )] = 0;
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goto propagateNaN_ZC;
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}
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if ( prodIsInfinite && (signProd != signC) ) goto invalid;
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goto copyC;
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}
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if ( prodIsInfinite ) {
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uiZ96 = packToF128UI96( signProd, 0x7FFF, 0 );
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goto uiZ;
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}
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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if ( expA ) {
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sigA[indexWordHi( 4 )] = fracF128UI96( uiA96 ) | 0x00010000;
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sigA[indexWord( 4, 2 )] = aWPtr[indexWord( 4, 2 )];
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sigA[indexWord( 4, 1 )] = aWPtr[indexWord( 4, 1 )];
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sigA[indexWord( 4, 0 )] = aWPtr[indexWord( 4, 0 )];
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} else {
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expA = softfloat_shiftNormSigF128M( aWPtr, 0, sigA );
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if ( expA == -128 ) goto zeroProd;
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}
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if ( expB ) {
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sigX[indexWordHi( 4 )] = fracF128UI96( uiB96 ) | 0x00010000;
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sigX[indexWord( 4, 2 )] = bWPtr[indexWord( 4, 2 )];
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sigX[indexWord( 4, 1 )] = bWPtr[indexWord( 4, 1 )];
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sigX[indexWord( 4, 0 )] = bWPtr[indexWord( 4, 0 )];
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} else {
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expB = softfloat_shiftNormSigF128M( bWPtr, 0, sigX );
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if ( expB == -128 ) goto zeroProd;
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}
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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expProd = expA + expB - 0x3FF0;
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softfloat_mul128MTo256M( sigA, sigX, sigProd );
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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wordSig = fracF128UI96( uiC96 );
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if ( expC ) {
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--expC;
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wordSig |= 0x00010000;
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}
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sigX[indexWordHi( 5 )] = wordSig;
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sigX[indexWord( 5, 3 )] = cWPtr[indexWord( 4, 2 )];
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sigX[indexWord( 5, 2 )] = cWPtr[indexWord( 4, 1 )];
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sigX[indexWord( 5, 1 )] = cWPtr[indexWord( 4, 0 )];
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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doSub = (signProd != signC);
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addCarryMRoutinePtr =
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doSub ? softfloat_addComplCarryM : softfloat_addCarryM;
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expDiff = expProd - expC;
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if ( expDiff <= 0 ) {
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/*--------------------------------------------------------------------
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*--------------------------------------------------------------------*/
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signZ = signC;
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expZ = expC;
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if (
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sigProd[indexWord( 8, 2 )]
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|| (sigProd[indexWord( 8, 1 )] | sigProd[indexWord( 8, 0 )])
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) {
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sigProd[indexWord( 8, 3 )] |= 1;
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}
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extSigPtr = &sigProd[indexMultiwordHi( 8, 5 )];
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if ( expDiff ) {
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softfloat_shiftRightJam160M( extSigPtr, -expDiff, extSigPtr );
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}
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carry = 0;
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if ( doSub ) {
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wordSig = extSigPtr[indexWordLo( 5 )];
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extSigPtr[indexWordLo( 5 )] = -wordSig;
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carry = ! wordSig;
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}
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(*addCarryMRoutinePtr)(
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4,
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&sigX[indexMultiwordHi( 5, 4 )],
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extSigPtr + indexMultiwordHi( 5, 4 ),
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carry,
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extSigPtr + indexMultiwordHi( 5, 4 )
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);
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wordSig = extSigPtr[indexWordHi( 5 )];
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if ( ! expZ ) {
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if ( wordSig & 0x80000000 ) {
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signZ = ! signZ;
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softfloat_negX160M( extSigPtr );
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wordSig = extSigPtr[indexWordHi( 5 )];
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}
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goto checkCancellation;
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}
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if ( wordSig < 0x00010000 ) {
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--expZ;
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softfloat_add160M( extSigPtr, extSigPtr, extSigPtr );
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goto roundPack;
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}
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goto extSigReady_noCancellation;
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} else {
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/*--------------------------------------------------------------------
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*--------------------------------------------------------------------*/
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signZ = signProd;
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expZ = expProd;
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sigX[indexWordLo( 5 )] = 0;
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expDiff -= 128;
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if ( 0 <= expDiff ) {
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/*----------------------------------------------------------------
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*----------------------------------------------------------------*/
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if ( expDiff ) softfloat_shiftRightJam160M( sigX, expDiff, sigX );
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wordSig = sigX[indexWordLo( 5 )];
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carry = 0;
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if ( doSub ) {
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carry = ! wordSig;
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wordSig = -wordSig;
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}
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carry =
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(*addCarryMRoutinePtr)(
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4,
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&sigProd[indexMultiwordLo( 8, 4 )],
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&sigX[indexMultiwordHi( 5, 4 )],
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carry,
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&sigProd[indexMultiwordLo( 8, 4 )]
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);
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sigProd[indexWord( 8, 2 )] |= wordSig;
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ptr = &sigProd[indexWord( 8, 4 )];
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} else {
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/*----------------------------------------------------------------
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*----------------------------------------------------------------*/
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shiftDist = expDiff & 31;
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if ( shiftDist ) {
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softfloat_shortShiftRight160M( sigX, shiftDist, sigX );
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}
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expDiff >>= 5;
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extSigPtr =
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&sigProd[indexMultiwordLo( 8, 5 )] - wordIncr
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+ expDiff * -wordIncr;
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carry =
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(*addCarryMRoutinePtr)( 5, extSigPtr, sigX, doSub, extSigPtr );
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if ( expDiff == -4 ) {
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/*------------------------------------------------------------
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*------------------------------------------------------------*/
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wordSig = sigProd[indexWordHi( 8 )];
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if ( wordSig & 0x80000000 ) {
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signZ = ! signZ;
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softfloat_negX256M( sigProd );
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wordSig = sigProd[indexWordHi( 8 )];
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}
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/*------------------------------------------------------------
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*------------------------------------------------------------*/
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if ( wordSig ) goto expProdBigger_noWordShift;
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wordSig = sigProd[indexWord( 8, 6 )];
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if ( 0x00040000 <= wordSig ) goto expProdBigger_noWordShift;
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expZ -= 32;
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extSigPtr = &sigProd[indexMultiwordHi( 8, 5 )] - wordIncr;
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for (;;) {
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if ( wordSig ) break;
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wordSig = extSigPtr[indexWord( 5, 3 )];
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if ( 0x00040000 <= wordSig ) break;
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expZ -= 32;
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extSigPtr -= wordIncr;
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if ( extSigPtr == &sigProd[indexMultiwordLo( 8, 5 )] ) {
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goto checkCancellation;
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}
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}
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/*------------------------------------------------------------
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*------------------------------------------------------------*/
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ptr = extSigPtr + indexWordLo( 5 );
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do {
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ptr -= wordIncr;
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if ( *ptr ) {
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extSigPtr[indexWordLo( 5 )] |= 1;
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break;
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}
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} while ( ptr != &sigProd[indexWordLo( 8 )] );
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wordSig = extSigPtr[indexWordHi( 5 )];
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goto extSigReady;
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}
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ptr = extSigPtr + indexWordHi( 5 ) + wordIncr;
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}
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/*--------------------------------------------------------------------
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*--------------------------------------------------------------------*/
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if ( carry != doSub ) {
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if ( doSub ) {
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do {
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wordSig = *ptr;
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*ptr = wordSig - 1;
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ptr += wordIncr;
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} while ( ! wordSig );
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} else {
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do {
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wordSig = *ptr + 1;
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*ptr = wordSig;
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ptr += wordIncr;
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} while ( ! wordSig );
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}
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}
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/*--------------------------------------------------------------------
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*--------------------------------------------------------------------*/
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expProdBigger_noWordShift:
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if (
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sigProd[indexWord( 8, 2 )]
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|| (sigProd[indexWord( 8, 1 )] | sigProd[indexWord( 8, 0 )])
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) {
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sigProd[indexWord( 8, 3 )] |= 1;
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}
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extSigPtr = &sigProd[indexMultiwordHi( 8, 5 )];
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wordSig = extSigPtr[indexWordHi( 5 )];
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}
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extSigReady:
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roundPackRoutinePtr = softfloat_normRoundPackMToF128M;
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if ( wordSig < 0x00010000 ) goto doRoundPack;
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extSigReady_noCancellation:
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if ( 0x00020000 <= wordSig ) {
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++expZ;
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softfloat_shortShiftRightJam160M( extSigPtr, 1, extSigPtr );
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}
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roundPack:
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roundPackRoutinePtr = softfloat_roundPackMToF128M;
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doRoundPack:
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(*roundPackRoutinePtr)( signZ, expZ, extSigPtr, zWPtr );
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return;
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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invalid:
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softfloat_invalidF128M( zWPtr );
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propagateNaN_ZC:
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softfloat_propagateNaNF128M( zWPtr, cWPtr, zWPtr );
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return;
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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zeroProd:
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if (
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! (uint32_t) (uiC96<<1) && (signProd != signC)
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&& ! cWPtr[indexWord( 4, 2 )]
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&& ! (cWPtr[indexWord( 4, 1 )] | cWPtr[indexWord( 4, 0 )])
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) {
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goto completeCancellation;
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}
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copyC:
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zWPtr[indexWordHi( 4 )] = uiC96;
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zWPtr[indexWord( 4, 2 )] = cWPtr[indexWord( 4, 2 )];
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zWPtr[indexWord( 4, 1 )] = cWPtr[indexWord( 4, 1 )];
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zWPtr[indexWord( 4, 0 )] = cWPtr[indexWord( 4, 0 )];
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return;
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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checkCancellation:
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if (
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wordSig
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|| (extSigPtr[indexWord( 5, 3 )] | extSigPtr[indexWord( 5, 2 )])
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|| (extSigPtr[indexWord( 5, 1 )] | extSigPtr[indexWord( 5, 0 )])
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) {
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goto extSigReady;
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}
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completeCancellation:
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uiZ96 =
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packToF128UI96(
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(softfloat_roundingMode == softfloat_round_min), 0, 0 );
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uiZ:
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zWPtr[indexWordHi( 4 )] = uiZ96;
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zWPtr[indexWord( 4, 2 )] = 0;
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zWPtr[indexWord( 4, 1 )] = 0;
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zWPtr[indexWord( 4, 0 )] = 0;
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}
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