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Diffstat (limited to 'source/f128M_roundToInt.c')
| -rw-r--r-- | source/f128M_roundToInt.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/source/f128M_roundToInt.c b/source/f128M_roundToInt.c new file mode 100644 index 0000000..39c4f4a --- /dev/null +++ b/source/f128M_roundToInt.c @@ -0,0 +1,212 @@ + +/*============================================================================ + +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 "specialize.h" +#include "softfloat.h" + +#ifdef SOFTFLOAT_FAST_INT64 + +void + f128M_roundToInt( + const float128_t *aPtr, + uint_fast8_t roundingMode, + bool exact, + float128_t *zPtr + ) +{ + + *zPtr = f128_roundToInt( *aPtr, roundingMode, exact ); + +} + +#else + +void + f128M_roundToInt( + const float128_t *aPtr, + uint_fast8_t roundingMode, + bool exact, + float128_t *zPtr + ) +{ + const uint32_t *aWPtr; + uint32_t *zWPtr; + uint32_t ui96; + int32_t exp; + uint32_t sigExtra; + bool sign; + uint_fast8_t bitPos; + bool roundNear; + unsigned int index, lastIndex; + bool extra; + uint32_t wordA, bit, wordZ; + uint_fast8_t carry; + uint32_t extrasMask; + + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + aWPtr = (const uint32_t *) aPtr; + zWPtr = (uint32_t *) zPtr; + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + ui96 = aWPtr[indexWordHi( 4 )]; + exp = expF128UI96( ui96 ); + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( exp < 0x3FFF ) { + zWPtr[indexWord( 4, 2 )] = 0; + zWPtr[indexWord( 4, 1 )] = 0; + zWPtr[indexWord( 4, 0 )] = 0; + sigExtra = aWPtr[indexWord( 4, 2 )]; + if ( ! sigExtra ) { + sigExtra = aWPtr[indexWord( 4, 1 )] | aWPtr[indexWord( 4, 0 )]; + } + if ( ! sigExtra && ! (ui96 & 0x7FFFFFFF) ) goto ui96; + if ( exact ) softfloat_exceptionFlags |= softfloat_flag_inexact; + sign = signF128UI96( ui96 ); + switch ( roundingMode ) { + case softfloat_round_near_even: + if ( ! fracF128UI96( ui96 ) && ! sigExtra ) break; + case softfloat_round_near_maxMag: + if ( exp == 0x3FFE ) goto mag1; + break; + case softfloat_round_min: + if ( sign ) goto mag1; + break; + case softfloat_round_max: + if ( ! sign ) goto mag1; + break; + } + ui96 = packToF128UI96( sign, 0, 0 ); + goto ui96; + mag1: + ui96 = packToF128UI96( sign, 0x3FFF, 0 ); + goto ui96; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( 0x406F <= exp ) { + if ( + (exp == 0x7FFF) + && (fracF128UI96( ui96 ) + || (aWPtr[indexWord( 4, 2 )] | aWPtr[indexWord( 4, 1 )] + | aWPtr[indexWord( 4, 0 )])) + ) { + softfloat_propagateNaNF128M( aWPtr, 0, zWPtr ); + return; + } + zWPtr[indexWord( 4, 2 )] = aWPtr[indexWord( 4, 2 )]; + zWPtr[indexWord( 4, 1 )] = aWPtr[indexWord( 4, 1 )]; + zWPtr[indexWord( 4, 0 )] = aWPtr[indexWord( 4, 0 )]; + goto ui96; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + bitPos = 0x406F - exp; + roundNear = + (roundingMode == softfloat_round_near_maxMag) + || (roundingMode == softfloat_round_near_even); + bitPos -= roundNear; + index = indexWordLo( 4 ); + lastIndex = indexWordHi( 4 ); + extra = 0; + for (;;) { + wordA = aWPtr[index]; + if ( bitPos < 32 ) break; + if ( wordA ) extra = 1; + zWPtr[index] = 0; + index += wordIncr; + bitPos -= 32; + } + bit = (uint32_t) 1<<bitPos; + if ( roundNear ) { + wordZ = wordA + bit; + carry = (wordZ < wordA); + bit <<= 1; + extrasMask = bit - 1; + if ( + (roundingMode == softfloat_round_near_even) + && ! extra && ! (wordZ & extrasMask) + ) { + if ( ! bit ) { + zWPtr[index] = wordZ; + index += wordIncr; + wordZ = aWPtr[index] + carry; + carry &= ! wordZ; + zWPtr[index] = wordZ & ~1; + goto propagateCarry; + } + wordZ &= ~bit; + } + } else { + extrasMask = bit - 1; + wordZ = wordA; + carry = 0; + if ( + (roundingMode != softfloat_round_minMag) + && (signF128UI96( ui96 ) ^ (roundingMode == softfloat_round_max)) + ) { + if ( extra || (wordA & extrasMask) ) { + wordZ += bit; + carry = (wordZ < wordA); + } + } + } + wordZ &= ~extrasMask; + zWPtr[index] = wordZ; + propagateCarry: + while ( index != lastIndex ) { + index += wordIncr; + wordZ = aWPtr[index] + carry; + zWPtr[index] = wordZ; + carry &= ! wordZ; + } + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + if ( exact && (softfloat_compare128M( aWPtr, zWPtr ) != 0) ) { + softfloat_exceptionFlags |= softfloat_flag_inexact; + } + return; + /*------------------------------------------------------------------------ + *------------------------------------------------------------------------*/ + ui96: + zWPtr[indexWordHi( 4 )] = ui96; + +} + +#endif + |