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88 lines
3.2 KiB
C
88 lines
3.2 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 The Regents of the University of California
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(Regents). All Rights Reserved. Redistribution and use in source and binary
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forms, with or without modification, are permitted provided that the following
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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 f32_to_i64( float32_t a, uint_fast8_t roundingMode, bool exact )
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{
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union ui32_f32 uA;
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uint_fast32_t uiA;
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bool sign;
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int_fast16_t exp;
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uint_fast32_t sig;
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int_fast16_t shiftCount;
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#ifdef SOFTFLOAT_FAST_INT64
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uint_fast64_t sig64, extra;
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struct uint64_extra sig64Extra;
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#else
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uint32_t extSig[3];
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#endif
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uA.f = a;
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uiA = uA.ui;
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sign = signF32UI( uiA );
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exp = expF32UI( uiA );
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sig = fracF32UI( uiA );
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shiftCount = 0xBE - exp;
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if ( shiftCount < 0 ) {
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softfloat_raiseFlags( softfloat_flag_invalid );
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if ( ! sign || ((exp == 0xFF) && sig) ) {
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return INT64_C( 0x7FFFFFFFFFFFFFFF );
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}
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return -INT64_C( 0x7FFFFFFFFFFFFFFF ) - 1;
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}
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if ( exp ) sig |= 0x00800000;
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#ifdef SOFTFLOAT_FAST_INT64
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sig64 = (uint_fast64_t) sig<<40;
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extra = 0;
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if ( shiftCount ) {
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sig64Extra = softfloat_shiftRightJam64Extra( sig64, 0, shiftCount );
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sig64 = sig64Extra.v;
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extra = sig64Extra.extra;
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}
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return softfloat_roundPackToI64( sign, sig64, extra, roundingMode, exact );
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#else
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extSig[indexWord( 3, 2 )] = sig<<8;
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extSig[indexWord( 3, 1 )] = 0;
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extSig[indexWord( 3, 0 )] = 0;
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if ( shiftCount ) softfloat_shiftRightJam96M( extSig, shiftCount, extSig );
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return softfloat_roundPackMToI64( sign, extSig, roundingMode, exact );
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#endif
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}
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