Eyck Jentzsch
dcaf5467e8
(http://www.jhauser.us/arithmetic/SoftFloat.html) with RISCV specialization and cmake build
140 lines
5.3 KiB
C
140 lines
5.3 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 The Regents of the University of California.
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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_mul(
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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_mul( *aPtr, *bPtr );
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}
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#else
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void
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extF80M_mul(
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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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uint_fast16_t exp, uiZ64;
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uint64_t uiZ0, sigA, sigB;
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int32_t expZ;
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uint32_t sigProd[4], *extSigZPtr;
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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 (
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(! aSPtr->signif && (expA != 0x7FFF))
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|| (! bSPtr->signif && (expB != 0x7FFF))
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) {
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softfloat_invalidExtF80M( zSPtr );
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return;
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}
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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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*------------------------------------------------------------------------*/
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if ( ! expA ) expA = 1;
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sigA = aSPtr->signif;
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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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if ( ! expB ) expB = 1;
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sigB = bSPtr->signif;
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if ( ! (sigB & UINT64_C( 0x8000000000000000 )) ) {
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if ( ! sigB ) goto zero;
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expB += softfloat_normExtF80SigM( &sigB );
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}
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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expZ = expA + expB - 0x3FFE;
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softfloat_mul64To128M( sigA, sigB, sigProd );
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if ( sigProd[indexWordLo( 4 )] ) sigProd[indexWord( 4, 1 )] |= 1;
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extSigZPtr = &sigProd[indexMultiwordHi( 4, 3 )];
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if ( sigProd[indexWordHi( 4 )] < 0x80000000 ) {
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--expZ;
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softfloat_add96M( extSigZPtr, extSigZPtr, extSigZPtr );
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}
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softfloat_roundPackMToExtF80M(
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signZ, expZ, extSigZPtr, extF80_roundingPrecision, zSPtr );
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return;
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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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