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84 lines
3.1 KiB
C
84 lines
3.1 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 3, by John R. Hauser.
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Copyright 2011, 2012, 2013, 2014, 2015 The Regents of the University of
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California (Regents). All Rights Reserved. Redistribution and use in source
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and binary forms, with or without modification, are permitted provided that
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the following conditions are met:
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Redistributions of source code must retain the above copyright notice,
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this list of conditions, and the following two paragraphs of disclaimer.
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Redistributions in binary form must reproduce the above copyright notice,
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this list of conditions, and the following two paragraphs of disclaimer in the
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documentation and/or other materials provided with the distribution. Neither
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the name of the Regents nor the names of its contributors may be used to
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endorse or promote products derived from this software without specific prior
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written permission.
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IN NO EVENT SHALL REGENTS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
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SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING
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OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF REGENTS HAS
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BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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REGENTS SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED
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TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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PURPOSE. THE SOFTWARE AND ACCOMPANYING DOCUMENTATION, IF ANY, PROVIDED
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HEREUNDER IS PROVIDED "AS IS". REGENTS HAS NO OBLIGATION TO PROVIDE
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MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
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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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int_fast64_t
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softfloat_roundPackToI64(
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bool sign,
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uint_fast64_t sig,
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uint_fast64_t sigExtra,
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uint_fast8_t roundingMode,
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bool exact
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)
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{
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bool roundNearEven, doIncrement;
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union { uint64_t ui; int64_t i; } uZ;
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int_fast64_t z;
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roundNearEven = (roundingMode == softfloat_round_near_even);
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doIncrement = (UINT64_C( 0x8000000000000000 ) <= sigExtra);
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if ( ! roundNearEven && (roundingMode != softfloat_round_near_maxMag) ) {
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doIncrement =
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(roundingMode
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== (sign ? softfloat_round_min : softfloat_round_max))
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&& sigExtra;
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}
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if ( doIncrement ) {
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++sig;
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if ( ! sig ) goto invalid;
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sig &=
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~(uint_fast64_t)
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(! (sigExtra & UINT64_C( 0x7FFFFFFFFFFFFFFF ))
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& roundNearEven);
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}
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uZ.ui = sign ? -sig : sig;
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z = uZ.i;
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if ( z && ((z < 0) ^ sign) ) goto invalid;
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if ( exact && sigExtra ) {
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softfloat_exceptionFlags |= softfloat_flag_inexact;
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}
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return z;
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invalid:
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softfloat_raiseFlags( softfloat_flag_invalid );
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return
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sign ? -INT64_C( 0x7FFFFFFFFFFFFFFF ) - 1
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: INT64_C( 0x7FFFFFFFFFFFFFFF );
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}
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