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Diffstat (limited to 'source/f64_to_i64.c')
| -rw-r--r-- | source/f64_to_i64.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/source/f64_to_i64.c b/source/f64_to_i64.c new file mode 100644 index 0000000..12ac88b --- /dev/null +++ b/source/f64_to_i64.c @@ -0,0 +1,104 @@ + +/*============================================================================ + +This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic +Package, Release 3, by John R. Hauser. + +Copyright 2011, 2012, 2013, 2014 The Regents of the University of California +(Regents). All Rights Reserved. Redistribution and use in source and binary +forms, with or without modification, are permitted provided that the following +conditions are met: + +Redistributions of source code must retain the above copyright notice, +this list of conditions, and the following two paragraphs of disclaimer. +Redistributions in binary form must reproduce the above copyright notice, +this list of conditions, and the following two paragraphs of disclaimer in the +documentation and/or other materials provided with the distribution. Neither +the name of the Regents nor the names of its contributors may be used to +endorse or promote products derived from this software without specific prior +written permission. + +IN NO EVENT SHALL REGENTS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, +SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING +OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF REGENTS HAS +BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +REGENTS SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED +TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR +PURPOSE. THE SOFTWARE AND ACCOMPANYING DOCUMENTATION, IF ANY, PROVIDED +HEREUNDER IS PROVIDED "AS IS". REGENTS HAS NO OBLIGATION TO PROVIDE +MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. + +=============================================================================*/ + +#include <stdbool.h> +#include <stdint.h> +#include "platform.h" +#include "internals.h" +#include "softfloat.h" + +int_fast64_t f64_to_i64( float64_t a, uint_fast8_t roundingMode, bool exact ) +{ + union ui64_f64 uA; + uint_fast64_t uiA; + bool sign; + int_fast16_t exp; + uint_fast64_t sig; + int_fast16_t shiftCount; +#ifdef SOFTFLOAT_FAST_INT64 + struct uint64_extra sigExtra; +#else + uint32_t extSig[3]; +#endif + + uA.f = a; + uiA = uA.ui; + sign = signF64UI( uiA ); + exp = expF64UI( uiA ); + sig = fracF64UI( uiA ); + if ( exp ) sig |= UINT64_C( 0x0010000000000000 ); + shiftCount = 0x433 - exp; +#ifdef SOFTFLOAT_FAST_INT64 + if ( shiftCount <= 0 ) { + if ( shiftCount < -11 ) { + softfloat_raiseFlags( softfloat_flag_invalid ); + return + ! sign + || ((exp == 0x7FF) + && (sig != UINT64_C( 0x0010000000000000 ))) + ? INT64_C( 0x7FFFFFFFFFFFFFFF ) + : -INT64_C( 0x7FFFFFFFFFFFFFFF ) - 1; + } + sigExtra.v = sig<<-shiftCount; + sigExtra.extra = 0; + } else { + sigExtra = softfloat_shiftRightJam64Extra( sig, 0, shiftCount ); + } + return + softfloat_roundPackToI64( + sign, sigExtra.v, sigExtra.extra, roundingMode, exact ); +#else + extSig[indexWord( 3, 0 )] = 0; + if ( shiftCount <= 0 ) { + if ( shiftCount < -11 ) { + softfloat_raiseFlags( softfloat_flag_invalid ); + return + ! sign + || ((exp == 0x7FF) + && (sig != UINT64_C( 0x0010000000000000 ))) + ? INT64_C( 0x7FFFFFFFFFFFFFFF ) + : -INT64_C( 0x7FFFFFFFFFFFFFFF ) - 1; + } + sig <<= -shiftCount; + extSig[indexWord( 3, 2 )] = sig>>32; + extSig[indexWord( 3, 1 )] = sig; + } else { + extSig[indexWord( 3, 2 )] = sig>>32; + extSig[indexWord( 3, 1 )] = sig; + softfloat_shiftRightJam96M( extSig, shiftCount, extSig ); + } + return softfloat_roundPackMToI64( sign, extSig, roundingMode, exact ); +#endif + +} + |