mirror of
https://github.com/urbit/shrub.git
synced 2024-12-25 04:52:06 +03:00
148 lines
5.4 KiB
C
148 lines
5.4 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"
|
|
#include "softfloat.h"
|
|
|
|
float64_t f64_mul( float64_t a, float64_t b )
|
|
{
|
|
union ui64_f64 uA;
|
|
uint_fast64_t uiA;
|
|
bool signA;
|
|
int_fast16_t expA;
|
|
uint_fast64_t sigA;
|
|
union ui64_f64 uB;
|
|
uint_fast64_t uiB;
|
|
bool signB;
|
|
int_fast16_t expB;
|
|
uint_fast64_t sigB;
|
|
bool signZ;
|
|
uint_fast64_t magBits;
|
|
struct exp16_sig64 normExpSig;
|
|
int_fast16_t expZ;
|
|
#ifdef SOFTFLOAT_FAST_INT64
|
|
struct uint128 sig128Z;
|
|
#else
|
|
uint32_t sig128Z[4];
|
|
#endif
|
|
uint_fast64_t sigZ, uiZ;
|
|
union ui64_f64 uZ;
|
|
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
uA.f = a;
|
|
uiA = uA.ui;
|
|
signA = signF64UI( uiA );
|
|
expA = expF64UI( uiA );
|
|
sigA = fracF64UI( uiA );
|
|
uB.f = b;
|
|
uiB = uB.ui;
|
|
signB = signF64UI( uiB );
|
|
expB = expF64UI( uiB );
|
|
sigB = fracF64UI( uiB );
|
|
signZ = signA ^ signB;
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
if ( expA == 0x7FF ) {
|
|
if ( sigA || ((expB == 0x7FF) && sigB) ) goto propagateNaN;
|
|
magBits = expB | sigB;
|
|
goto infArg;
|
|
}
|
|
if ( expB == 0x7FF ) {
|
|
if ( sigB ) goto propagateNaN;
|
|
magBits = expA | sigA;
|
|
goto infArg;
|
|
}
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
if ( ! expA ) {
|
|
if ( ! sigA ) goto zero;
|
|
normExpSig = softfloat_normSubnormalF64Sig( sigA );
|
|
expA = normExpSig.exp;
|
|
sigA = normExpSig.sig;
|
|
}
|
|
if ( ! expB ) {
|
|
if ( ! sigB ) goto zero;
|
|
normExpSig = softfloat_normSubnormalF64Sig( sigB );
|
|
expB = normExpSig.exp;
|
|
sigB = normExpSig.sig;
|
|
}
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
expZ = expA + expB - 0x3FF;
|
|
sigA = (sigA | UINT64_C( 0x0010000000000000 ))<<10;
|
|
sigB = (sigB | UINT64_C( 0x0010000000000000 ))<<11;
|
|
#ifdef SOFTFLOAT_FAST_INT64
|
|
sig128Z = softfloat_mul64To128( sigA, sigB );
|
|
sigZ = sig128Z.v64 | (sig128Z.v0 != 0);
|
|
#else
|
|
softfloat_mul64To128M( sigA, sigB, sig128Z );
|
|
sigZ =
|
|
(uint64_t) sig128Z[indexWord( 4, 3 )]<<32 | sig128Z[indexWord( 4, 2 )];
|
|
if ( sig128Z[indexWord( 4, 1 )] || sig128Z[indexWord( 4, 0 )] ) sigZ |= 1;
|
|
#endif
|
|
if ( sigZ < UINT64_C( 0x4000000000000000 ) ) {
|
|
--expZ;
|
|
sigZ <<= 1;
|
|
}
|
|
return softfloat_roundPackToF64( signZ, expZ, sigZ );
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
propagateNaN:
|
|
uiZ = softfloat_propagateNaNF64UI( uiA, uiB );
|
|
goto uiZ;
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
infArg:
|
|
if ( ! magBits ) {
|
|
softfloat_raiseFlags( softfloat_flag_invalid );
|
|
uiZ = defaultNaNF64UI;
|
|
} else {
|
|
uiZ = packToF64UI( signZ, 0x7FF, 0 );
|
|
}
|
|
goto uiZ;
|
|
/*------------------------------------------------------------------------
|
|
*------------------------------------------------------------------------*/
|
|
zero:
|
|
uiZ = packToF64UI( signZ, 0, 0 );
|
|
uiZ:
|
|
uZ.ui = uiZ;
|
|
return uZ.f;
|
|
|
|
}
|
|
|