135 lines
4.6 KiB
C
135 lines
4.6 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 <stdbool.h>
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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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float32 f32_range(float32 a, float32 b, bool is_max, bool is_abs, int sign_ctrl, struct softfloat_status_t *status)
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{
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bool signA;
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int16_t expA;
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uint32_t sigA;
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bool signB;
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int16_t expB;
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uint32_t sigB;
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bool aIsNaN, bIsNaN;
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uint32_t z;
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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signA = signF32UI(a);
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expA = expF32UI(a);
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sigA = fracF32UI(a);
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signB = signF32UI(b);
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expB = expF32UI(b);
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sigB = fracF32UI(b);
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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if (softfloat_isSigNaNF32UI(a)) {
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return softfloat_propagateNaNF32UI(a, 0, status);
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}
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if (softfloat_isSigNaNF32UI(b)) {
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return softfloat_propagateNaNF32UI(b, 0, status);
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}
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aIsNaN = isNaNF32UI(a);
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bIsNaN = isNaNF32UI(b);
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/*------------------------------------------------------------------------
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*------------------------------------------------------------------------*/
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if (! expA && sigA) {
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if (softfloat_denormalsAreZeros(status)) {
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a = packToF32UI(signA, 0, 0);
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}
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else if (! bIsNaN) {
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softfloat_raiseFlags(status, softfloat_flag_denormal);
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}
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}
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if (! expB && sigB) {
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if (softfloat_denormalsAreZeros(status)) {
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b = packToF32UI(signB, 0, 0);
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}
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else if (! aIsNaN) {
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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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*------------------------------------------------------------------------*/
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if (bIsNaN) {
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z = a;
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}
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else if (aIsNaN) {
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z = b;
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}
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else if (signA != signB && ! is_abs) {
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if (! is_max) {
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z = signA ? a : b;
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} else {
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z = signA ? b : a;
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}
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} else {
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float32 tmp_a = a, tmp_b = b;
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if (is_abs) {
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tmp_a = tmp_a & ~0x80000000; // clear the sign bit
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tmp_b = tmp_b & ~0x80000000;
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signA = 0;
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}
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if (! is_max) {
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z = (signA ^ (tmp_a < tmp_b)) ? a : b;
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} else {
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z = (signA ^ (tmp_a < tmp_b)) ? b : a;
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}
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}
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switch(sign_ctrl) {
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case 0:
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z = (z & ~0x80000000) | (a & 0x80000000); // keep sign of a
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break;
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case 1:
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break; // preserve sign of compare result
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case 2:
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z = z & ~0x80000000; // zero out the sign bit
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break;
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case 3:
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z = z | 0x80000000; // set the sign bit
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break;
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}
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return z;
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}
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