179 lines
7.2 KiB
C
179 lines
7.2 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, 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 "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;
|
|
}
|
|
}
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
uj = extSigPtr[indexWord( 5, 1 )];
|
|
if ( sigExtra ) {
|
|
softfloat_exceptionFlags |= softfloat_flag_inexact;
|
|
#ifdef SOFTFLOAT_ROUND_ODD
|
|
if ( roundingMode == softfloat_round_odd ) {
|
|
uj |= 1;
|
|
goto noIncrementPackReturn;
|
|
}
|
|
#endif
|
|
}
|
|
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 {
|
|
noIncrementPackReturn:
|
|
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 );
|
|
|
|
}
|
|
|