mirror of
https://github.com/urbit/shrub.git
synced 2024-12-18 15:55:00 +03:00
109 lines
3.8 KiB
C
109 lines
3.8 KiB
C
|
|
/*============================================================================
|
|
|
|
This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
|
|
Package, Release 3, by John R. Hauser.
|
|
|
|
Copyright 2011, 2012, 2013, 2014 The Regents of the University of California
|
|
(Regents). All Rights Reserved. Redistribution and use in source and binary
|
|
forms, with or without modification, are permitted provided that the following
|
|
conditions are met:
|
|
|
|
Redistributions of source code must retain the above copyright notice,
|
|
this list of conditions, and the following two paragraphs of disclaimer.
|
|
Redistributions in binary form must reproduce the above copyright notice,
|
|
this list of conditions, and the following two paragraphs of disclaimer in the
|
|
documentation and/or other materials provided with the distribution. Neither
|
|
the name of the Regents nor the names of its contributors may be used to
|
|
endorse or promote products derived from this software without specific prior
|
|
written permission.
|
|
|
|
IN NO EVENT SHALL REGENTS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
|
|
SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING
|
|
OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF REGENTS HAS
|
|
BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
REGENTS SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED
|
|
TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
PURPOSE. THE SOFTWARE AND ACCOMPANYING DOCUMENTATION, IF ANY, PROVIDED
|
|
HEREUNDER IS PROVIDED "AS IS". REGENTS HAS NO OBLIGATION TO PROVIDE
|
|
MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
|
|
|
|
=============================================================================*/
|
|
|
|
#include <stdbool.h>
|
|
#include <stdint.h>
|
|
#include "platform.h"
|
|
#include "internals.h"
|
|
#include "specialize.h"
|
|
|
|
float64_t
|
|
softfloat_addMagsF64( 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_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;
|
|
sigA <<= 9;
|
|
sigB <<= 9;
|
|
if ( ! expDiff ) {
|
|
if ( expA == 0x7FF ) {
|
|
if ( sigA | sigB ) goto propagateNaN;
|
|
uiZ = uiA;
|
|
goto uiZ;
|
|
}
|
|
if ( ! expA ) {
|
|
uiZ =
|
|
packToF64UI(
|
|
signZ, 0, (uiA + uiB) & UINT64_C( 0x7FFFFFFFFFFFFFFF ) );
|
|
goto uiZ;
|
|
}
|
|
expZ = expA;
|
|
sigZ = UINT64_C( 0x4000000000000000 ) + sigA + sigB;
|
|
} else {
|
|
if ( expDiff < 0 ) {
|
|
if ( expB == 0x7FF ) {
|
|
if ( sigB ) goto propagateNaN;
|
|
uiZ = packToF64UI( signZ, 0x7FF, 0 );
|
|
goto uiZ;
|
|
}
|
|
expZ = expB;
|
|
sigA += expA ? UINT64_C( 0x2000000000000000 ) : sigA;
|
|
sigA = softfloat_shiftRightJam64( sigA, -expDiff );
|
|
} else {
|
|
if ( expA == 0x7FF ) {
|
|
if ( sigA ) goto propagateNaN;
|
|
uiZ = uiA;
|
|
goto uiZ;
|
|
}
|
|
expZ = expA;
|
|
sigB += expB ? UINT64_C( 0x2000000000000000 ) : sigB;
|
|
sigB = softfloat_shiftRightJam64( sigB, expDiff );
|
|
}
|
|
sigZ = UINT64_C( 0x2000000000000000 ) + sigA + sigB;
|
|
if ( sigZ < UINT64_C( 0x4000000000000000 ) ) {
|
|
--expZ;
|
|
sigZ <<= 1;
|
|
}
|
|
}
|
|
return softfloat_roundPackToF64( signZ, expZ, sigZ );
|
|
propagateNaN:
|
|
uiZ = softfloat_propagateNaNF64UI( uiA, uiB );
|
|
uiZ:
|
|
uZ.ui = uiZ;
|
|
return uZ.f;
|
|
|
|
}
|
|
|