148 lines
5.9 KiB
C++
148 lines
5.9 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 <stdio.h>
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#include <stdint.h>
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#include <86box/86box.h>
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#include "../cpu.h"
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#include "internals.h"
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#include "softfloat.h"
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/*----------------------------------------------------------------------------
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| Compare between two extended precision floating point numbers. Returns
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| 'float_relation_equal' if the operands are equal, 'float_relation_less' if
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| the value 'a' is less than the corresponding value `b',
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| 'float_relation_greater' if the value 'a' is greater than the corresponding
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| value `b', or 'float_relation_unordered' otherwise.
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*----------------------------------------------------------------------------*/
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int extF80_compare(extFloat80_t a, extFloat80_t b, int quiet, 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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uint16_t uiB64;
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uint64_t uiB0;
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bool signB;
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int32_t expB;
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uint64_t sigB;
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struct exp32_sig64 normExpSig;
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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softfloat_class_t aClass = extF80_class(a);
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softfloat_class_t bClass = extF80_class(b);
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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if (fpu_type < FPU_287XL) {
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if ((aClass == softfloat_positive_inf) && (bClass == softfloat_negative_inf))
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{
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return softfloat_relation_equal;
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}
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if ((aClass == softfloat_negative_inf) && (bClass == softfloat_positive_inf))
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{
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return softfloat_relation_equal;
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}
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}
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if (aClass == softfloat_SNaN || bClass == softfloat_SNaN)
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{
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/* unsupported reported as SNaN */
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softfloat_raiseFlags(status, softfloat_flag_invalid);
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return softfloat_relation_unordered;
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}
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if (aClass == softfloat_QNaN || bClass == softfloat_QNaN) {
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if (! quiet) softfloat_raiseFlags(status, softfloat_flag_invalid);
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return softfloat_relation_unordered;
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}
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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if (aClass == softfloat_denormal || bClass == softfloat_denormal) {
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softfloat_raiseFlags(status, softfloat_flag_denormal);
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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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uiB64 = b.signExp;
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uiB0 = b.signif;
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signB = signExtF80UI64(uiB64);
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expB = expExtF80UI64(uiB64);
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sigB = uiB0;
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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if (aClass == softfloat_zero) {
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if (bClass == softfloat_zero) return softfloat_relation_equal;
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return signB ? softfloat_relation_greater : softfloat_relation_less;
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}
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if (bClass == softfloat_zero || signA != signB) {
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return signA ? softfloat_relation_less : softfloat_relation_greater;
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}
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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if (aClass == softfloat_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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if (bClass == softfloat_denormal) {
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normExpSig = softfloat_normSubnormalExtF80Sig(sigB);
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expB += normExpSig.exp + 1;
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sigB = normExpSig.sig;
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}
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if (expA == expB && sigA == sigB)
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return softfloat_relation_equal;
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int less_than =
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signA ? ((expB < expA) || ((expB == expA) && (sigB < sigA)))
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: ((expA < expB) || ((expA == expB) && (sigA < sigB)));
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if (less_than) return softfloat_relation_less;
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return softfloat_relation_greater;
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}
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