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105 lines
3.9 KiB
C
105 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 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 f64_to_i64( float64_t a, uint_fast8_t roundingMode, bool exact )
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{
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union ui64_f64 uA;
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uint_fast64_t uiA;
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bool sign;
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int_fast16_t exp;
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uint_fast64_t sig;
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int_fast16_t shiftCount;
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#ifdef SOFTFLOAT_FAST_INT64
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struct uint64_extra sigExtra;
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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 = signF64UI( uiA );
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exp = expF64UI( uiA );
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sig = fracF64UI( uiA );
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if ( exp ) sig |= UINT64_C( 0x0010000000000000 );
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shiftCount = 0x433 - exp;
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#ifdef SOFTFLOAT_FAST_INT64
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if ( shiftCount <= 0 ) {
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if ( shiftCount < -11 ) {
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softfloat_raiseFlags( softfloat_flag_invalid );
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return
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! sign
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|| ((exp == 0x7FF)
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&& (sig != UINT64_C( 0x0010000000000000 )))
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? INT64_C( 0x7FFFFFFFFFFFFFFF )
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: -INT64_C( 0x7FFFFFFFFFFFFFFF ) - 1;
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}
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sigExtra.v = sig<<-shiftCount;
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sigExtra.extra = 0;
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} else {
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sigExtra = softfloat_shiftRightJam64Extra( sig, 0, shiftCount );
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}
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return
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softfloat_roundPackToI64(
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sign, sigExtra.v, sigExtra.extra, roundingMode, exact );
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#else
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extSig[indexWord( 3, 0 )] = 0;
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if ( shiftCount <= 0 ) {
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if ( shiftCount < -11 ) {
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softfloat_raiseFlags( softfloat_flag_invalid );
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return
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! sign
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|| ((exp == 0x7FF)
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&& (sig != UINT64_C( 0x0010000000000000 )))
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? INT64_C( 0x7FFFFFFFFFFFFFFF )
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: -INT64_C( 0x7FFFFFFFFFFFFFFF ) - 1;
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}
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sig <<= -shiftCount;
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extSig[indexWord( 3, 2 )] = sig>>32;
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extSig[indexWord( 3, 1 )] = sig;
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} else {
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extSig[indexWord( 3, 2 )] = sig>>32;
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extSig[indexWord( 3, 1 )] = sig;
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softfloat_shiftRightJam96M( extSig, shiftCount, extSig );
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}
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return softfloat_roundPackMToI64( sign, extSig, roundingMode, exact );
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#endif
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}
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