mirror of
git://sourceware.org/git/glibc.git
synced 2024-11-27 03:41:23 +08:00
63 lines
1.6 KiB
C
63 lines
1.6 KiB
C
/* s_rintl.c -- long double version of s_rint.c.
|
|
* Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
|
|
*/
|
|
|
|
/*
|
|
* ====================================================
|
|
* 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.
|
|
* ====================================================
|
|
*/
|
|
|
|
#if defined(LIBM_SCCS) && !defined(lint)
|
|
static char rcsid[] = "$NetBSD: $";
|
|
#endif
|
|
|
|
/*
|
|
* rintl(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 rintl(x).
|
|
*/
|
|
|
|
#include <math.h>
|
|
#include <math_private.h>
|
|
|
|
static const long double
|
|
TWO112[2]={
|
|
5.19229685853482762853049632922009600E+33L, /* 0x406F000000000000, 0 */
|
|
-5.19229685853482762853049632922009600E+33L /* 0xC06F000000000000, 0 */
|
|
};
|
|
|
|
long double __rintl(long double x)
|
|
{
|
|
int64_t i0,j0,sx;
|
|
u_int64_t i1 __attribute__ ((unused));
|
|
long double w,t;
|
|
GET_LDOUBLE_WORDS64(i0,i1,x);
|
|
sx = (((u_int64_t)i0)>>63);
|
|
j0 = ((i0>>48)&0x7fff)-0x3fff;
|
|
if(j0<112) {
|
|
if(j0<0) {
|
|
w = TWO112[sx]+x;
|
|
t = w-TWO112[sx];
|
|
GET_LDOUBLE_MSW64(i0,t);
|
|
SET_LDOUBLE_MSW64(t,(i0&0x7fffffffffffffffLL)|(sx<<63));
|
|
return t;
|
|
}
|
|
} else {
|
|
if(j0==0x4000) return x+x; /* inf or NaN */
|
|
else return x; /* x is integral */
|
|
}
|
|
w = TWO112[sx]+x;
|
|
return w-TWO112[sx];
|
|
}
|
|
weak_alias (__rintl, rintl)
|