mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-05 03:01:05 +00:00
92 lines
2.2 KiB
C
92 lines
2.2 KiB
C
/* s_rintl.c -- long double version of s_rint.c.
|
|
* Conversion to long double by Ulrich Drepper,
|
|
* Cygnus Support, drepper@cygnus.com.
|
|
*/
|
|
|
|
/*
|
|
* ====================================================
|
|
* 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"
|
|
|
|
#ifdef __STDC__
|
|
static const long double
|
|
#else
|
|
static long double
|
|
#endif
|
|
TWO63[2]={
|
|
9.223372036854775808000000e+18, /* 0x403E, 0x00000000, 0x00000000 */
|
|
-9.223372036854775808000000e+18 /* 0xC03E, 0x00000000, 0x00000000 */
|
|
};
|
|
|
|
#ifdef __STDC__
|
|
long double __rintl(long double x)
|
|
#else
|
|
long double __rintl(x)
|
|
long double x;
|
|
#endif
|
|
{
|
|
int32_t se,j0,sx;
|
|
u_int32_t i,i0,i1;
|
|
long double w,t;
|
|
GET_LDOUBLE_WORDS(se,i0,i1,x);
|
|
sx = (se>>15)&1;
|
|
j0 = (se&0x7fff)-0x3fff;
|
|
if(j0<31) {
|
|
if(j0<0) {
|
|
if(((se&0x7fff)|i0|i1)==0) return x;
|
|
i1 |= i0;
|
|
i0 &= 0xe0000000;
|
|
i0 |= (i1|-i1)&0x80000000;
|
|
SET_LDOUBLE_MSW(x,i0);
|
|
w = TWO63[sx]+x;
|
|
t = w-TWO63[sx];
|
|
GET_LDOUBLE_EXP(i0,t);
|
|
SET_LDOUBLE_EXP(t,(i0&0x7fff)|(sx<<15));
|
|
return t;
|
|
} else {
|
|
i = (0x7fffffff)>>j0;
|
|
if(((i0&i)|i1)==0) return x; /* x is integral */
|
|
i>>=1;
|
|
if(((i0&i)|i1)!=0) {
|
|
if(j0==30) i1 = 0x40000000; else
|
|
i0 = (i0&(~i))|((0x20000000)>>j0);
|
|
}
|
|
}
|
|
} else if (j0>62) {
|
|
if(j0==0x4000) return x+x; /* inf or NaN */
|
|
else return x; /* x is integral */
|
|
} else {
|
|
i = ((u_int32_t)(0xffffffff))>>(j0-31);
|
|
if((i1&i)==0) return x; /* x is integral */
|
|
i>>=1;
|
|
if((i1&i)!=0) i1 = (i1&(~i))|((0x40000000)>>(j0-31));
|
|
}
|
|
SET_LDOUBLE_WORDS(x,se,i0,i1);
|
|
w = TWO63[sx]+x;
|
|
return w-TWO63[sx];
|
|
}
|
|
weak_alias (__rintl, rintl)
|