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Diffstat (limited to 'source/s_roundPackMToF128M.c')
| -rw-r--r-- | source/s_roundPackMToF128M.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/source/s_roundPackMToF128M.c b/source/s_roundPackMToF128M.c new file mode 100644 index 0000000..e7a2329 --- /dev/null +++ b/source/s_roundPackMToF128M.c @@ -0,0 +1,156 @@ + +/*============================================================================ + +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" + +void + softfloat_roundPackMToF128M( + bool sign, int32_t exp, uint32_t *extSigPtr, uint32_t *zWPtr ) +{ + uint_fast8_t roundingMode; + bool roundNearEven; + uint32_t sigExtra; + bool doIncrement, isTiny; + static const uint32_t maxSig[4] = + INIT_UINTM4( 0x0001FFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF ); + uint32_t ui, uj; + + roundingMode = softfloat_roundingMode; + roundNearEven = (roundingMode == softfloat_round_near_even); + sigExtra = extSigPtr[indexWordLo( 5 )]; + doIncrement = (0x80000000 <= sigExtra); + if ( ! roundNearEven && (roundingMode != softfloat_round_near_maxMag) ) { + doIncrement = + (roundingMode + == (sign ? softfloat_round_min : softfloat_round_max)) + && sigExtra; + } + if ( 0x7FFD <= (uint32_t) exp ) { + if ( exp < 0 ) { + isTiny = + (softfloat_detectTininess + == softfloat_tininess_beforeRounding) + || (exp < -1) + || ! doIncrement + || (softfloat_compare128M( + extSigPtr + indexMultiwordHi( 5, 4 ), maxSig ) + < 0); + softfloat_shiftRightJam160M( extSigPtr, -exp, extSigPtr ); + exp = 0; + sigExtra = extSigPtr[indexWordLo( 5 )]; + if ( isTiny && sigExtra ) { + softfloat_raiseFlags( softfloat_flag_underflow ); + } + doIncrement = (0x80000000 <= sigExtra); + if ( + ! roundNearEven + && (roundingMode != softfloat_round_near_maxMag) + ) { + doIncrement = + (roundingMode + == (sign ? softfloat_round_min : softfloat_round_max)) + && sigExtra; + } + } else if ( + (0x7FFD < exp) + || ((exp == 0x7FFD) && doIncrement + && (softfloat_compare128M( + extSigPtr + indexMultiwordHi( 5, 4 ), maxSig ) + == 0)) + ) { + softfloat_raiseFlags( + softfloat_flag_overflow | softfloat_flag_inexact ); + if ( + roundNearEven + || (roundingMode == softfloat_round_near_maxMag) + || (roundingMode + == (sign ? softfloat_round_min : softfloat_round_max)) + ) { + ui = packToF128UI96( sign, 0x7FFF, 0 ); + uj = 0; + } else { + ui = packToF128UI96( sign, 0x7FFE, 0x0000FFFF ); + uj = 0xFFFFFFFF; + } + zWPtr[indexWordHi( 4 )] = ui; + zWPtr[indexWord( 4, 2 )] = uj; + zWPtr[indexWord( 4, 1 )] = uj; + zWPtr[indexWord( 4, 0 )] = uj; + return; + } + } + if ( sigExtra ) softfloat_exceptionFlags |= softfloat_flag_inexact; + uj = extSigPtr[indexWord( 5, 1 )]; + if ( doIncrement ) { + ++uj; + if ( uj ) { + if ( ! (sigExtra & 0x7FFFFFFF) && roundNearEven ) uj &= ~1; + zWPtr[indexWord( 4, 2 )] = extSigPtr[indexWord( 5, 3 )]; + zWPtr[indexWord( 4, 1 )] = extSigPtr[indexWord( 5, 2 )]; + zWPtr[indexWord( 4, 0 )] = uj; + ui = extSigPtr[indexWordHi( 5 )]; + } else { + zWPtr[indexWord( 4, 0 )] = uj; + ui = extSigPtr[indexWord( 5, 2 )] + 1; + zWPtr[indexWord( 4, 1 )] = ui; + uj = extSigPtr[indexWord( 5, 3 )]; + if ( ui ) { + zWPtr[indexWord( 4, 2 )] = uj; + ui = extSigPtr[indexWordHi( 5 )]; + } else { + ++uj; + zWPtr[indexWord( 4, 2 )] = uj; + ui = extSigPtr[indexWordHi( 5 )]; + if ( ! uj ) ++ui; + } + } + } else { + zWPtr[indexWord( 4, 0 )] = uj; + ui = extSigPtr[indexWord( 5, 2 )]; + zWPtr[indexWord( 4, 1 )] = ui; + uj |= ui; + ui = extSigPtr[indexWord( 5, 3 )]; + zWPtr[indexWord( 4, 2 )] = ui; + uj |= ui; + ui = extSigPtr[indexWordHi( 5 )]; + uj |= ui; + if ( ! uj ) exp = 0; + } + zWPtr[indexWordHi( 4 )] = packToF128UI96( sign, exp, ui ); + +} + |