ubuntu-buildroot/output/build/glibc-2.36-81-g4f4d7a13edfd.../sysdeps/ieee754/ldbl-128/s_rintl.c

76 lines
1.8 KiB
C

/* s_rintl.c -- long double version of s_rint.c.
*/
/*
* ====================================================
* 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).
*/
#define NO_MATH_REDIRECT
#include <math.h>
#include <math_private.h>
#include <libm-alias-ldouble.h>
#include <math-use-builtins.h>
_Float128
__rintl (_Float128 x)
{
#if USE_RINTL_BUILTIN
return __builtin_rintl (x);
#else
/* Use generic implementation. */
static const _Float128
TWO112[2] = {
5.19229685853482762853049632922009600E+33L, /* 0x406F000000000000, 0 */
-5.19229685853482762853049632922009600E+33L /* 0xC06F000000000000, 0 */
};
int64_t i0, j0, sx;
uint64_t i1 __attribute__ ((unused));
_Float128 w, t;
GET_LDOUBLE_WORDS64 (i0, i1, x);
sx = (((uint64_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];
#endif /* ! USE_RINTL_BUILTIN */
}
libm_alias_ldouble (__rint, rint)