mirror of
https://github.com/ilyakooo0/urbit.git
synced 2024-12-18 20:31:40 +03:00
142 lines
5.5 KiB
C
142 lines
5.5 KiB
C
|
|
/*============================================================================
|
|
|
|
This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
|
|
Package, Release 3c, by John R. Hauser.
|
|
|
|
Copyright 2011, 2012, 2013, 2014, 2015, 2016 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
|
|
softfloat_subMagsF64( uint_fast64_t uiA, uint_fast64_t uiB, bool signZ )
|
|
{
|
|
int_fast16_t expA;
|
|
uint_fast64_t sigA;
|
|
int_fast16_t expB;
|
|
uint_fast64_t sigB;
|
|
int_fast16_t expDiff;
|
|
uint_fast64_t uiZ;
|
|
int_fast64_t sigDiff;
|
|
int_fast8_t shiftDist;
|
|
int_fast16_t expZ;
|
|
uint_fast64_t sigZ;
|
|
union ui64_f64 uZ;
|
|
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
expA = expF64UI( uiA );
|
|
sigA = fracF64UI( uiA );
|
|
expB = expF64UI( uiB );
|
|
sigB = fracF64UI( uiB );
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
expDiff = expA - expB;
|
|
if ( ! expDiff ) {
|
|
/*--------------------------------------------------------------------
|
|
*--------------------------------------------------------------------*/
|
|
if ( expA == 0x7FF ) {
|
|
if ( sigA | sigB ) goto propagateNaN;
|
|
softfloat_raiseFlags( softfloat_flag_invalid );
|
|
uiZ = defaultNaNF64UI;
|
|
goto uiZ;
|
|
}
|
|
sigDiff = sigA - sigB;
|
|
if ( ! sigDiff ) {
|
|
uiZ =
|
|
packToF64UI(
|
|
(softfloat_roundingMode == softfloat_round_min), 0, 0 );
|
|
goto uiZ;
|
|
}
|
|
if ( expA ) --expA;
|
|
if ( sigDiff < 0 ) {
|
|
signZ = ! signZ;
|
|
sigDiff = -sigDiff;
|
|
}
|
|
shiftDist = softfloat_countLeadingZeros64( sigDiff ) - 11;
|
|
expZ = expA - shiftDist;
|
|
if ( expZ < 0 ) {
|
|
shiftDist = expA;
|
|
expZ = 0;
|
|
}
|
|
uiZ = packToF64UI( signZ, expZ, sigDiff<<shiftDist );
|
|
goto uiZ;
|
|
} else {
|
|
/*--------------------------------------------------------------------
|
|
*--------------------------------------------------------------------*/
|
|
sigA <<= 10;
|
|
sigB <<= 10;
|
|
if ( expDiff < 0 ) {
|
|
/*----------------------------------------------------------------
|
|
*----------------------------------------------------------------*/
|
|
signZ = ! signZ;
|
|
if ( expB == 0x7FF ) {
|
|
if ( sigB ) goto propagateNaN;
|
|
uiZ = packToF64UI( signZ, 0x7FF, 0 );
|
|
goto uiZ;
|
|
}
|
|
sigA += expA ? UINT64_C( 0x4000000000000000 ) : sigA;
|
|
sigA = softfloat_shiftRightJam64( sigA, -expDiff );
|
|
sigB |= UINT64_C( 0x4000000000000000 );
|
|
expZ = expB;
|
|
sigZ = sigB - sigA;
|
|
} else {
|
|
/*----------------------------------------------------------------
|
|
*----------------------------------------------------------------*/
|
|
if ( expA == 0x7FF ) {
|
|
if ( sigA ) goto propagateNaN;
|
|
uiZ = uiA;
|
|
goto uiZ;
|
|
}
|
|
sigB += expB ? UINT64_C( 0x4000000000000000 ) : sigB;
|
|
sigB = softfloat_shiftRightJam64( sigB, expDiff );
|
|
sigA |= UINT64_C( 0x4000000000000000 );
|
|
expZ = expA;
|
|
sigZ = sigA - sigB;
|
|
}
|
|
return softfloat_normRoundPackToF64( signZ, expZ - 1, sigZ );
|
|
}
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
propagateNaN:
|
|
uiZ = softfloat_propagateNaNF64UI( uiA, uiB );
|
|
uiZ:
|
|
uZ.ui = uiZ;
|
|
return uZ.f;
|
|
|
|
}
|
|
|