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// See LICENSE.SoftFloat for license details.
#include <stdbool.h>
#include <stdint.h>
#include "platform.h"
#include "primitives.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;
struct uint128 sigZ128;
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;
sigZ128 = softfloat_mul64To128( sigA, sigB );
sigZ = sigZ128.v64 | ( sigZ128.v0 != 0 );
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;
}
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