| |
| /*============================================================================ |
| |
| This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic |
| Package, Release 3d, by John R. Hauser. |
| |
| Copyright 2011, 2012, 2013, 2014, 2017 The Regents of the University of |
| California. All rights reserved. |
| |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions are met: |
| |
| 1. Redistributions of source code must retain the above copyright notice, |
| this list of conditions, and the following disclaimer. |
| |
| 2. Redistributions in binary form must reproduce the above copyright notice, |
| this list of conditions, and the following disclaimer in the documentation |
| and/or other materials provided with the distribution. |
| |
| 3. Neither the name of the University nor the names of its contributors may |
| be used to endorse or promote products derived from this software without |
| specific prior written permission. |
| |
| THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS", AND ANY |
| EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE |
| DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY |
| DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| =============================================================================*/ |
| |
| #include <stdbool.h> |
| #include <stdint.h> |
| #include "platform.h" |
| #include "internals.h" |
| #include "specialize.h" |
| #include "softfloat.h" |
| |
| float64_t f64_roundToInt( float64_t a, uint_fast8_t roundingMode, bool exact ) |
| { |
| union ui64_f64 uA; |
| uint_fast64_t uiA; |
| int_fast16_t exp; |
| uint_fast64_t uiZ, lastBitMask, roundBitsMask; |
| union ui64_f64 uZ; |
| |
| /*------------------------------------------------------------------------ |
| *------------------------------------------------------------------------*/ |
| uA.f = a; |
| uiA = uA.ui; |
| exp = expF64UI( uiA ); |
| /*------------------------------------------------------------------------ |
| *------------------------------------------------------------------------*/ |
| if ( exp <= 0x3FE ) { |
| if ( ! (uiA & UINT64_C( 0x7FFFFFFFFFFFFFFF )) ) return a; |
| if ( exact ) softfloat_exceptionFlags |= softfloat_flag_inexact; |
| uiZ = uiA & packToF64UI( 1, 0, 0 ); |
| switch ( roundingMode ) { |
| case softfloat_round_near_even: |
| if ( ! fracF64UI( uiA ) ) break; |
| case softfloat_round_near_maxMag: |
| if ( exp == 0x3FE ) uiZ |= packToF64UI( 0, 0x3FF, 0 ); |
| break; |
| case softfloat_round_min: |
| if ( uiZ ) uiZ = packToF64UI( 1, 0x3FF, 0 ); |
| break; |
| case softfloat_round_max: |
| if ( ! uiZ ) uiZ = packToF64UI( 0, 0x3FF, 0 ); |
| break; |
| } |
| goto uiZ; |
| } |
| /*------------------------------------------------------------------------ |
| *------------------------------------------------------------------------*/ |
| if ( 0x433 <= exp ) { |
| if ( (exp == 0x7FF) && fracF64UI( uiA ) ) { |
| uiZ = softfloat_propagateNaNF64UI( uiA, 0 ); |
| goto uiZ; |
| } |
| return a; |
| } |
| /*------------------------------------------------------------------------ |
| *------------------------------------------------------------------------*/ |
| uiZ = uiA; |
| lastBitMask = (uint_fast64_t) 1<<(0x433 - 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 |
| == (signF64UI( uiZ ) ? softfloat_round_min : softfloat_round_max) |
| ) { |
| uiZ += roundBitsMask; |
| } |
| uiZ &= ~roundBitsMask; |
| if ( exact && (uiZ != uiA) ) { |
| softfloat_exceptionFlags |= softfloat_flag_inexact; |
| } |
| uiZ: |
| uZ.ui = uiZ; |
| return uZ.f; |
| |
| } |
| |