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195 lines
7.1 KiB
C
195 lines
7.1 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 3c, 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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#ifdef SOFTFLOAT_FAST_INT64
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void
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extF80M_div(
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const extFloat80_t *aPtr, const extFloat80_t *bPtr, extFloat80_t *zPtr )
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{
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*zPtr = extF80_div( *aPtr, *bPtr );
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}
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#else
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void
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extF80M_div(
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const extFloat80_t *aPtr, const extFloat80_t *bPtr, extFloat80_t *zPtr )
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{
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const struct extFloat80M *aSPtr, *bSPtr;
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struct extFloat80M *zSPtr;
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uint_fast16_t uiA64;
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int32_t expA;
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uint_fast16_t uiB64;
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int32_t expB;
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bool signZ;
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uint64_t sigA, x64;
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int32_t expZ;
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int shiftDist;
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uint32_t y[3], recip32, sigB[3];
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int ix;
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uint32_t q, qs[2];
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uint_fast16_t uiZ64;
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uint64_t uiZ0;
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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aSPtr = (const struct extFloat80M *) aPtr;
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bSPtr = (const struct extFloat80M *) bPtr;
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zSPtr = (struct extFloat80M *) zPtr;
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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uiA64 = aSPtr->signExp;
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expA = expExtF80UI64( uiA64 );
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uiB64 = bSPtr->signExp;
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expB = expExtF80UI64( uiB64 );
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signZ = signExtF80UI64( uiA64 ) ^ signExtF80UI64( uiB64 );
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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if ( (expA == 0x7FFF) || (expB == 0x7FFF) ) {
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if ( softfloat_tryPropagateNaNExtF80M( aSPtr, bSPtr, zSPtr ) ) return;
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if ( expA == 0x7FFF ) {
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if ( expB == 0x7FFF ) goto invalid;
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goto infinity;
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}
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goto zero;
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}
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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sigA = aSPtr->signif;
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x64 = bSPtr->signif;
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if ( ! expB ) expB = 1;
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if ( ! (x64 & UINT64_C( 0x8000000000000000 )) ) {
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if ( ! x64 ) {
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if ( ! sigA ) goto invalid;
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softfloat_raiseFlags( softfloat_flag_infinite );
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goto infinity;
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}
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expB += softfloat_normExtF80SigM( &x64 );
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}
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if ( ! expA ) expA = 1;
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if ( ! (sigA & UINT64_C( 0x8000000000000000 )) ) {
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if ( ! sigA ) goto zero;
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expA += softfloat_normExtF80SigM( &sigA );
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}
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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expZ = expA - expB + 0x3FFF;
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shiftDist = 29;
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if ( sigA < x64 ) {
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--expZ;
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shiftDist = 30;
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}
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softfloat_shortShiftLeft64To96M( sigA, shiftDist, y );
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recip32 = softfloat_approxRecip32_1( x64>>32 );
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sigB[indexWord( 3, 0 )] = (uint32_t) x64<<30;
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x64 >>= 2;
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sigB[indexWord( 3, 2 )] = x64>>32;
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sigB[indexWord( 3, 1 )] = x64;
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ix = 2;
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for (;;) {
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x64 = (uint64_t) y[indexWordHi( 3 )] * recip32;
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q = (x64 + 0x80000000)>>32;
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--ix;
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if ( ix < 0 ) break;
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softfloat_remStep96MBy32( y, 29, sigB, q, y );
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if ( y[indexWordHi( 3 )] & 0x80000000 ) {
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--q;
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softfloat_add96M( y, sigB, y );
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}
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qs[ix] = q;
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}
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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if ( ((q + 1) & 0x3FFFFF) < 2 ) {
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softfloat_remStep96MBy32( y, 29, sigB, q, y );
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if ( y[indexWordHi( 3 )] & 0x80000000 ) {
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--q;
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softfloat_add96M( y, sigB, y );
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} else if ( softfloat_compare96M( sigB, y ) <= 0 ) {
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++q;
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softfloat_sub96M( y, sigB, y );
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}
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if (
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y[indexWordLo( 3 )] || y[indexWord( 3, 1 )] || y[indexWord( 3, 2 )]
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) {
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q |= 1;
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}
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}
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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x64 = (uint64_t) q<<9;
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y[indexWord( 3, 0 )] = x64;
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x64 = ((uint64_t) qs[0]<<6) + (x64>>32);
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y[indexWord( 3, 1 )] = x64;
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y[indexWord( 3, 2 )] = (qs[1]<<3) + (x64>>32);
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softfloat_roundPackMToExtF80M(
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signZ, expZ, y, extF80_roundingPrecision, zSPtr );
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return;
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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invalid:
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softfloat_invalidExtF80M( zSPtr );
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return;
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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infinity:
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uiZ64 = packToExtF80UI64( signZ, 0x7FFF );
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uiZ0 = UINT64_C( 0x8000000000000000 );
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goto uiZ;
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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zero:
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uiZ64 = packToExtF80UI64( signZ, 0 );
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uiZ0 = 0;
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uiZ:
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zSPtr->signExp = uiZ64;
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zSPtr->signif = uiZ0;
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}
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#endif
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