| |
| /*============================================================================ |
| |
| 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" |
| |
| float32_t f32_roundToInt( float32_t a, uint_fast8_t roundingMode, bool exact ) |
| { |
| union ui32_f32 uA; |
| uint_fast32_t uiA; |
| int_fast16_t exp; |
| uint_fast32_t uiZ, lastBitMask, roundBitsMask; |
| union ui32_f32 uZ; |
| |
| /*------------------------------------------------------------------------ |
| *------------------------------------------------------------------------*/ |
| uA.f = a; |
| uiA = uA.ui; |
| exp = expF32UI( uiA ); |
| /*------------------------------------------------------------------------ |
| *------------------------------------------------------------------------*/ |
| if ( exp <= 0x7E ) { |
| if ( ! (uint32_t) (uiA<<1) ) return a; |
| if ( exact ) softfloat_exceptionFlags |= softfloat_flag_inexact; |
| uiZ = uiA & packToF32UI( 1, 0, 0 ); |
| switch ( roundingMode ) { |
| case softfloat_round_near_even: |
| if ( ! fracF32UI( uiA ) ) break; |
| case softfloat_round_near_maxMag: |
| if ( exp == 0x7E ) uiZ |= packToF32UI( 0, 0x7F, 0 ); |
| break; |
| case softfloat_round_min: |
| if ( uiZ ) uiZ = packToF32UI( 1, 0x7F, 0 ); |
| break; |
| case softfloat_round_max: |
| if ( ! uiZ ) uiZ = packToF32UI( 0, 0x7F, 0 ); |
| break; |
| } |
| goto uiZ; |
| } |
| /*------------------------------------------------------------------------ |
| *------------------------------------------------------------------------*/ |
| if ( 0x96 <= exp ) { |
| if ( (exp == 0xFF) && fracF32UI( uiA ) ) { |
| uiZ = softfloat_propagateNaNF32UI( uiA, 0 ); |
| goto uiZ; |
| } |
| return a; |
| } |
| /*------------------------------------------------------------------------ |
| *------------------------------------------------------------------------*/ |
| uiZ = uiA; |
| lastBitMask = (uint_fast32_t) 1<<(0x96 - exp); |
| roundBitsMask = lastBitMask - 1; |
| if ( roundingMode == softfloat_round_near_maxMag ) { |
| uiZ += lastBitMask>>1; |
| } else if ( roundingMode == softfloat_round_near_even ) { |
| uiZ += lastBitMask>>1; |
| if ( ! (uiZ & roundBitsMask) ) uiZ &= ~lastBitMask; |
| } else if ( roundingMode != softfloat_round_minMag ) { |
| if ( signF32UI( uiZ ) ^ (roundingMode == softfloat_round_max) ) { |
| uiZ += roundBitsMask; |
| } |
| } |
| uiZ &= ~roundBitsMask; |
| if ( exact && (uiZ != uiA) ) { |
| softfloat_exceptionFlags |= softfloat_flag_inexact; |
| } |
| uiZ: |
| uZ.ui = uiZ; |
| return uZ.f; |
| |
| } |
| |