mirror of
https://github.com/openhwgroup/cvw
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181 lines
6.4 KiB
C
181 lines
6.4 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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float32_t f32_div( float32_t a, float32_t b )
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{
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union ui32_f32 uA;
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uint_fast32_t uiA;
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bool signA;
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int_fast16_t expA;
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uint_fast32_t sigA;
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union ui32_f32 uB;
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uint_fast32_t uiB;
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bool signB;
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int_fast16_t expB;
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uint_fast32_t sigB;
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bool signZ;
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struct exp16_sig32 normExpSig;
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int_fast16_t expZ;
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#ifdef SOFTFLOAT_FAST_DIV64TO32
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uint_fast64_t sig64A;
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uint_fast32_t sigZ;
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#else
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uint_fast32_t sigZ;
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uint_fast64_t rem;
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#endif
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uint_fast32_t uiZ;
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union ui32_f32 uZ;
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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uA.f = a;
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uiA = uA.ui;
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signA = signF32UI( uiA );
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expA = expF32UI( uiA );
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sigA = fracF32UI( uiA );
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uB.f = b;
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uiB = uB.ui;
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signB = signF32UI( uiB );
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expB = expF32UI( uiB );
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sigB = fracF32UI( uiB );
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signZ = signA ^ signB;
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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if ( expA == 0xFF ) {
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if ( sigA ) goto propagateNaN;
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if ( expB == 0xFF ) {
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if ( sigB ) goto propagateNaN;
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goto invalid;
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}
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goto infinity;
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}
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if ( expB == 0xFF ) {
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if ( sigB ) goto propagateNaN;
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goto zero;
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}
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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if ( ! expB ) {
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if ( ! sigB ) {
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if ( ! (expA | 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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normExpSig = softfloat_normSubnormalF32Sig( sigB );
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expB = normExpSig.exp;
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sigB = normExpSig.sig;
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}
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if ( ! expA ) {
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if ( ! sigA ) goto zero;
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normExpSig = softfloat_normSubnormalF32Sig( sigA );
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expA = normExpSig.exp;
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sigA = normExpSig.sig;
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}
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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expZ = expA - expB + 0x7E;
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sigA |= 0x00800000;
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sigB |= 0x00800000;
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#ifdef SOFTFLOAT_FAST_DIV64TO32
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if ( sigA < sigB ) {
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--expZ;
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sig64A = (uint_fast64_t) sigA<<31;
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} else {
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sig64A = (uint_fast64_t) sigA<<30;
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}
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sigZ = sig64A / sigB;
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if ( ! (sigZ & 0x3F) ) sigZ |= ((uint_fast64_t) sigB * sigZ != sig64A);
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#else
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if ( sigA < sigB ) {
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--expZ;
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sigA <<= 8;
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} else {
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sigA <<= 7;
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}
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sigB <<= 8;
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sigZ = ((uint_fast64_t) sigA * softfloat_approxRecip32_1( sigB ))>>32;
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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sigZ += 2;
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if ( (sigZ & 0x3F) < 2 ) {
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sigZ &= ~3;
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#ifdef SOFTFLOAT_FAST_INT64
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rem = ((uint_fast64_t) sigA<<31) - (uint_fast64_t) sigZ * sigB;
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#else
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rem = ((uint_fast64_t) sigA<<32) - (uint_fast64_t) (sigZ<<1) * sigB;
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#endif
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if ( rem & UINT64_C( 0x8000000000000000 ) ) {
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sigZ -= 4;
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} else {
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if ( rem ) sigZ |= 1;
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}
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}
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#endif
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return softfloat_roundPackToF32( signZ, expZ, sigZ );
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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propagateNaN:
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uiZ = softfloat_propagateNaNF32UI( uiA, uiB );
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goto uiZ;
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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invalid:
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softfloat_raiseFlags( softfloat_flag_invalid );
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uiZ = defaultNaNF32UI;
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goto uiZ;
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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infinity:
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uiZ = packToF32UI( signZ, 0xFF, 0 );
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goto uiZ;
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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zero:
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uiZ = packToF32UI( signZ, 0, 0 );
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uiZ:
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uZ.ui = uiZ;
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return uZ.f;
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}
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