98 lines
4.2 KiB
C++
98 lines
4.2 KiB
C++
/*============================================================================
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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 <stdint.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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/*----------------------------------------------------------------------------
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| Separate the source extended double-precision floating point value `a'
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| into its exponent and significand, store the significant back to the
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| 'a' and return the exponent. The operation performed is a superset of
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| the IEC/IEEE recommended logb(x) function.
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*----------------------------------------------------------------------------*/
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extFloat80_t extF80_extract(extFloat80_t *a, struct softfloat_status_t *status)
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{
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uint16_t uiA64;
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uint64_t uiA0;
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bool signA;
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int32_t expA;
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uint64_t sigA;
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struct exp32_sig64 normExpSig;
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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// handle unsupported extended double-precision floating encodings
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if (extF80_isUnsupported(*a)) {
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softfloat_raiseFlags(status, softfloat_flag_invalid);
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*a = packToExtF80_twoargs(defaultNaNExtF80UI64, defaultNaNExtF80UI0);
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return *a;
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}
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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uiA64 = a->signExp;
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uiA0 = a->signif;
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signA = signExtF80UI64(uiA64);
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expA = expExtF80UI64(uiA64);
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sigA = uiA0;
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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if (expA == 0x7FFF) {
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if (sigA<<1) {
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*a = softfloat_propagateNaNExtF80UI(uiA64, uiA0, 0, 0, status);
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return *a;
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}
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return packToExtF80(0, 0x7FFF, BX_CONST64(0x8000000000000000));
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}
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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if (! expA) {
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if (! sigA) {
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softfloat_raiseFlags(status, softfloat_flag_divbyzero);
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*a = packToExtF80(signA, 0, 0);
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return packToExtF80(1, 0x7FFF, BX_CONST64(0x8000000000000000));
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}
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softfloat_raiseFlags(status, softfloat_flag_denormal);
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normExpSig = softfloat_normSubnormalExtF80Sig(sigA);
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expA = normExpSig.exp + 1;
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sigA = normExpSig.sig;
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}
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*a = packToExtF80(signA, 0x3FFF, sigA);
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return i32_to_extF80(expA - 0x3FFF);
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}
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