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Diffstat (limited to 'source/s_roundPackToI32.c')
-rw-r--r-- | source/s_roundPackToI32.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/source/s_roundPackToI32.c b/source/s_roundPackToI32.c new file mode 100644 index 0000000..e07dd00 --- /dev/null +++ b/source/s_roundPackToI32.c @@ -0,0 +1,76 @@ + +/*============================================================================ + +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_fast32_t + softfloat_roundPackToI32( + bool sign, uint_fast64_t sig, uint_fast8_t roundingMode, bool exact ) +{ + bool roundNearEven; + uint_fast8_t roundIncrement, roundBits; + uint_fast32_t sig32; + union { uint32_t ui; int32_t i; } uZ; + int_fast32_t z; + + roundNearEven = (roundingMode == softfloat_round_near_even); + roundIncrement = 0x40; + if ( ! roundNearEven && (roundingMode != softfloat_round_near_maxMag) ) { + roundIncrement = + (roundingMode + == (sign ? softfloat_round_min : softfloat_round_max)) + ? 0x7F + : 0; + } + roundBits = sig & 0x7F; + sig += roundIncrement; + if ( sig & UINT64_C( 0xFFFFFF8000000000 ) ) goto invalid; + sig32 = sig>>7; + sig32 &= ~(! (roundBits ^ 0x40) & roundNearEven); + uZ.ui = sign ? -sig32 : sig32; + z = uZ.i; + if ( z && ((z < 0) ^ sign) ) goto invalid; + if ( exact && roundBits ) { + softfloat_exceptionFlags |= softfloat_flag_inexact; + } + return z; + invalid: + softfloat_raiseFlags( softfloat_flag_invalid ); + return sign ? -0x7FFFFFFF - 1 : 0x7FFFFFFF; + +} + |