| |
| /*============================================================================ |
| |
| 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 ); |
| |
| } |
| |