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/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
/*
* rint(x)
* Return x rounded to integral value according to the prevailing
* rounding mode.
* Method:
* Using floating addition.
* Exception:
* Inexact flag raised if x not equal to rint(x).
*/
#include <math.h>
#include <math_private.h>
#include <libm-alias-double.h>
static const double
TWO52[2]={
4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */
-4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */
};
double
__rint(double x)
{
int64_t i0,sx;
int32_t j0;
EXTRACT_WORDS64(i0,x);
sx = (i0>>63)&1;
j0 = ((i0>>52)&0x7ff)-0x3ff;
if(j0<52) {
if(j0<0) {
double w = TWO52[sx]+x;
double t = w-TWO52[sx];
EXTRACT_WORDS64(i0,t);
INSERT_WORDS64(t,(i0&UINT64_C(0x7fffffffffffffff))|(sx<<63));
return t;
}
} else {
if(j0==0x400) return x+x; /* inf or NaN */
else return x; /* x is integral */
}
double w = TWO52[sx]+x;
return w-TWO52[sx];
}
#ifndef __rint
libm_alias_double (__rint, rint)
#endif
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