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#include <limits.h>
#include <math.h>
/*******************************************************************************
* *
* The function nearbyint rounds its double argument to integral value *
* according to the current rounding direction and returns the result in *
* double format. This function does not signal inexact. *
* *
********************************************************************************
* *
* This function calls fabs and copysign. *
* *
*******************************************************************************/
static const double twoTo52 = 4503599627370496.0;
libm_hidden_proto(nearbyint)
double nearbyint ( double x )
{
double y;
double OldEnvironment;
y = twoTo52;
asm ("mffs %0" : "=f" (OldEnvironment)); /* get the environement */
if ( fabs ( x ) >= y ) /* huge case is exact */
return x;
if ( x < 0 ) y = -y; /* negative case */
y = ( x + y ) - y; /* force rounding */
if ( y == 0.0 ) /* zero results mirror sign of x */
y = copysign ( y, x );
// restore old flags
asm ("mtfsf 255,%0" : /*NULLOUT*/ : /*IN*/ "f" ( OldEnvironment ));
return ( y );
}
libm_hidden_def(nearbyint)
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