102 lines
3.9 KiB
C
102 lines
3.9 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, 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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/*----------------------------------------------------------------------------
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| Extracts the fractional portion of single-precision floating-point value `a',
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| and returns the result as a single-precision floating-point value. The
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| fractional results are precise. The operation is performed according to the
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| IEC/IEEE Standard for Binary Floating-Point Arithmetic.
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*----------------------------------------------------------------------------*/
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float32 f32_frc(float32 a, struct softfloat_status_t *status)
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{
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int roundingMode = softfloat_getRoundingMode(status);
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bool signA;
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int16_t expA;
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uint32_t sigA;
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uint32_t lastBitMask;
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uint32_t roundBitsMask;
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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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if (expA == 0xFF) {
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if (sigA) return softfloat_propagateNaNF32UI(a, 0, status);
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softfloat_raiseFlags(status, softfloat_flag_invalid);
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return defaultNaNF32UI;
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}
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if (expA >= 0x96) {
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return packToF32UI(roundingMode == softfloat_round_down, 0, 0);
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}
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if (expA < 0x7F) {
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if (! expA) {
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if (! sigA || softfloat_denormalsAreZeros(status))
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return packToF32UI(roundingMode == softfloat_round_down, 0, 0);
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softfloat_raiseFlags(status, softfloat_flag_denormal);
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if (! softfloat_isMaskedException(status, softfloat_flag_underflow))
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softfloat_raiseFlags(status, softfloat_flag_underflow);
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if (softfloat_flushUnderflowToZero(status)) {
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softfloat_raiseFlags(status, softfloat_flag_underflow | softfloat_flag_inexact);
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return packToF32UI(signA, 0, 0);
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}
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}
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return a;
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}
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lastBitMask = 1 << (0x96 - expA);
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roundBitsMask = lastBitMask - 1;
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sigA &= roundBitsMask;
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sigA <<= 7;
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expA--;
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if (! sigA)
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return packToF32UI(roundingMode == softfloat_round_down, 0, 0);
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return softfloat_normRoundPackToF32(signA, expA, sigA, status);
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}
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