121 lines
4.7 KiB
C
121 lines
4.7 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, 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"
|
||
|
|
|
||
|
|
float16_t f16_roundToInt( float16_t a, uint_fast8_t roundingMode, bool exact )
|
||
|
|
{
|
||
|
|
union ui16_f16 uA;
|
||
|
|
uint_fast16_t uiA;
|
||
|
|
int_fast8_t exp;
|
||
|
|
uint_fast16_t uiZ, lastBitMask, roundBitsMask;
|
||
|
|
union ui16_f16 uZ;
|
||
|
|
|
||
|
|
/*------------------------------------------------------------------------
|
||
|
|
*------------------------------------------------------------------------*/
|
||
|
|
uA.f = a;
|
||
|
|
uiA = uA.ui;
|
||
|
|
exp = expF16UI( uiA );
|
||
|
|
/*------------------------------------------------------------------------
|
||
|
|
*------------------------------------------------------------------------*/
|
||
|
|
if ( exp <= 0xE ) {
|
||
|
|
if ( !(uint16_t) (uiA<<1) ) return a;
|
||
|
|
if ( exact ) softfloat_exceptionFlags |= softfloat_flag_inexact;
|
||
|
|
uiZ = uiA & packToF16UI( 1, 0, 0 );
|
||
|
|
switch ( roundingMode ) {
|
||
|
|
case softfloat_round_near_even:
|
||
|
|
if ( !fracF16UI( uiA ) ) break;
|
||
|
|
case softfloat_round_near_maxMag:
|
||
|
|
if ( exp == 0xE ) uiZ |= packToF16UI( 0, 0xF, 0 );
|
||
|
|
break;
|
||
|
|
case softfloat_round_min:
|
||
|
|
if ( uiZ ) uiZ = packToF16UI( 1, 0xF, 0 );
|
||
|
|
break;
|
||
|
|
case softfloat_round_max:
|
||
|
|
if ( !uiZ ) uiZ = packToF16UI( 0, 0xF, 0 );
|
||
|
|
break;
|
||
|
|
#ifdef SOFTFLOAT_ROUND_ODD
|
||
|
|
case softfloat_round_odd:
|
||
|
|
uiZ |= packToF16UI( 0, 0xF, 0 );
|
||
|
|
break;
|
||
|
|
#endif
|
||
|
|
}
|
||
|
|
goto uiZ;
|
||
|
|
}
|
||
|
|
/*------------------------------------------------------------------------
|
||
|
|
*------------------------------------------------------------------------*/
|
||
|
|
if ( 0x19 <= exp ) {
|
||
|
|
if ( (exp == 0x1F) && fracF16UI( uiA ) ) {
|
||
|
|
uiZ = softfloat_propagateNaNF16UI( uiA, 0 );
|
||
|
|
goto uiZ;
|
||
|
|
}
|
||
|
|
return a;
|
||
|
|
}
|
||
|
|
/*------------------------------------------------------------------------
|
||
|
|
*------------------------------------------------------------------------*/
|
||
|
|
uiZ = uiA;
|
||
|
|
lastBitMask = (uint_fast16_t) 1<<(0x19 - 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
|
||
|
|
== (signF16UI( uiZ ) ? softfloat_round_min : softfloat_round_max)
|
||
|
|
) {
|
||
|
|
uiZ += roundBitsMask;
|
||
|
|
}
|
||
|
|
uiZ &= ~roundBitsMask;
|
||
|
|
if ( uiZ != uiA ) {
|
||
|
|
#ifdef SOFTFLOAT_ROUND_ODD
|
||
|
|
if ( roundingMode == softfloat_round_odd ) uiZ |= lastBitMask;
|
||
|
|
#endif
|
||
|
|
if ( exact ) softfloat_exceptionFlags |= softfloat_flag_inexact;
|
||
|
|
}
|
||
|
|
uiZ:
|
||
|
|
uZ.ui = uiZ;
|
||
|
|
return uZ.f;
|
||
|
|
|
||
|
|
}
|
||
|
|
|