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#include <stdbool.h>
#include <stdint.h>
#include "platform.h"
#include "internals.h"
#include "specialize.h"
#include "softfloat.h"
float64_t f64_roundToInt( float64_t a, int_fast8_t roundingMode, bool exact )
{
union ui64_f64 uA;
uint_fast64_t uiA;
int_fast16_t expA;
uint_fast64_t uiZ;
bool signA;
uint_fast64_t lastBitMask, roundBitsMask;
union ui64_f64 uZ;
uA.f = a;
uiA = uA.ui;
expA = expF64UI( uiA );
if ( 0x433 <= expA ) {
if ( ( expA == 0x7FF ) && fracF64UI( uiA ) ) {
uiZ = softfloat_propagateNaNF64UI( uiA, 0 );
goto uiZ;
}
return a;
}
if ( expA <= 0x3FE ) {
if ( ! ( uiA & UINT64_C( 0x7FFFFFFFFFFFFFFF ) ) ) return a;
if ( exact ) softfloat_exceptionFlags |= softfloat_flag_inexact;
signA = signF64UI( uiA );
switch ( roundingMode ) {
case softfloat_round_nearest_even:
if ( ( expA == 0x3FE ) && fracF64UI( uiA ) ) {
uiZ = packToF64UI( signA, 0x3FF, 0 );
goto uiZ;
}
break;
case softfloat_round_min:
uiZ = signA ? UINT64_C( 0xBFF0000000000000 ) : 0;
goto uiZ;
case softfloat_round_max:
uiZ =
signA ? UINT64_C( 0x8000000000000000 )
: UINT64_C( 0x3FF0000000000000 );
goto uiZ;
case softfloat_round_nearest_maxMag:
if ( expA == 0x3FE ) {
uiZ = packToF64UI( signA, 0x3FF, 0 );
goto uiZ;
}
break;
}
uiZ = packToF64UI( signA, 0, 0 );
goto uiZ;
}
lastBitMask = (uint_fast64_t) 1<<( 0x433 - expA );
roundBitsMask = lastBitMask - 1;
uiZ = uiA;
if ( roundingMode == softfloat_round_nearest_maxMag ) {
uiZ += lastBitMask>>1;
} else if ( roundingMode == softfloat_round_nearest_even ) {
uiZ += lastBitMask>>1;
if ( ! ( uiZ & roundBitsMask ) ) uiZ &= ~ lastBitMask;
} else if ( roundingMode != softfloat_round_minMag ) {
if ( signF64UI( uiZ ) ^ ( roundingMode == softfloat_round_max ) ) {
uiZ += roundBitsMask;
}
}
uiZ &= ~ roundBitsMask;
if ( exact && ( uiZ != uiA ) ) {
softfloat_exceptionFlags |= softfloat_flag_inexact;
}
uiZ:
uZ.ui = uiZ;
return uZ.f;
}
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