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71 lines
2.7 KiB
C
71 lines
2.7 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 3c, 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 "platform.h"
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#include "internals.h"
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#include "softfloat.h"
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float16_t i64_to_f16( int64_t a )
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{
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bool sign;
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uint_fast64_t absA;
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int_fast8_t shiftDist;
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union ui16_f16 u;
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uint_fast16_t sig;
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sign = (a < 0);
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absA = sign ? -(uint_fast64_t) a : (uint_fast64_t) a;
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shiftDist = softfloat_countLeadingZeros64( absA ) - 53;
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if ( 0 <= shiftDist ) {
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u.ui =
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a ? packToF16UI(
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sign, 0x18 - shiftDist, (uint_fast16_t) absA<<shiftDist )
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: 0;
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return u.f;
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} else {
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shiftDist += 4;
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sig =
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(shiftDist < 0)
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? softfloat_shortShiftRightJam64( absA, -shiftDist )
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: (uint_fast16_t) absA<<shiftDist;
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return softfloat_roundPackToF16( sign, 0x1C - shiftDist, sig );
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}
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}
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