94 lines
3.6 KiB
C
94 lines
3.6 KiB
C
|
|
||
|
|
/*============================================================================
|
||
|
|
|
||
|
|
This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
|
||
|
|
Package, Release 3e, by John R. Hauser.
|
||
|
|
|
||
|
|
Copyright 2011, 2012, 2013, 2014, 2015, 2016, 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"
|
||
|
|
|
||
|
|
uint_fast32_t
|
||
|
|
softfloat_roundToUI32(
|
||
|
|
bool sign, uint_fast64_t sig, uint_fast8_t roundingMode, bool exact )
|
||
|
|
{
|
||
|
|
uint_fast16_t roundIncrement, roundBits;
|
||
|
|
uint_fast32_t z;
|
||
|
|
|
||
|
|
/*------------------------------------------------------------------------
|
||
|
|
*------------------------------------------------------------------------*/
|
||
|
|
roundIncrement = 0x800;
|
||
|
|
if (
|
||
|
|
(roundingMode != softfloat_round_near_maxMag)
|
||
|
|
&& (roundingMode != softfloat_round_near_even)
|
||
|
|
) {
|
||
|
|
roundIncrement = 0;
|
||
|
|
if ( sign ) {
|
||
|
|
if ( !sig ) return 0;
|
||
|
|
if ( roundingMode == softfloat_round_min ) goto invalid;
|
||
|
|
#ifdef SOFTFLOAT_ROUND_ODD
|
||
|
|
if ( roundingMode == softfloat_round_odd ) goto invalid;
|
||
|
|
#endif
|
||
|
|
} else {
|
||
|
|
if ( roundingMode == softfloat_round_max ) roundIncrement = 0xFFF;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
roundBits = sig & 0xFFF;
|
||
|
|
sig += roundIncrement;
|
||
|
|
if ( sig & UINT64_C( 0xFFFFF00000000000 ) ) goto invalid;
|
||
|
|
z = sig>>12;
|
||
|
|
if (
|
||
|
|
(roundBits == 0x800) && (roundingMode == softfloat_round_near_even)
|
||
|
|
) {
|
||
|
|
z &= ~(uint_fast32_t) 1;
|
||
|
|
}
|
||
|
|
if ( sign && z ) goto invalid;
|
||
|
|
if ( roundBits ) {
|
||
|
|
#ifdef SOFTFLOAT_ROUND_ODD
|
||
|
|
if ( roundingMode == softfloat_round_odd ) z |= 1;
|
||
|
|
#endif
|
||
|
|
if ( exact ) softfloat_exceptionFlags |= softfloat_flag_inexact;
|
||
|
|
}
|
||
|
|
return z;
|
||
|
|
/*------------------------------------------------------------------------
|
||
|
|
*------------------------------------------------------------------------*/
|
||
|
|
invalid:
|
||
|
|
softfloat_raiseFlags( softfloat_flag_invalid );
|
||
|
|
return sign ? ui32_fromNegOverflow : ui32_fromPosOverflow;
|
||
|
|
|
||
|
|
}
|
||
|
|
|