glibc/sysdeps/ieee754/ldbl-96/s_llrintl.c
Joseph Myers 688903eb3e Update copyright dates with scripts/update-copyrights.
* All files with FSF copyright notices: Update copyright dates
	using scripts/update-copyrights.
	* locale/programs/charmap-kw.h: Regenerated.
	* locale/programs/locfile-kw.h: Likewise.
2018-01-01 00:32:25 +00:00

93 lines
2.4 KiB
C

/* Round argument to nearest integral value according to current rounding
direction.
Copyright (C) 1997-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <fenv.h>
#include <limits.h>
#include <math.h>
#include <math_private.h>
#include <libm-alias-ldouble.h>
static const long double two63[2] =
{
9.223372036854775808000000e+18, /* 0x403E, 0x00000000, 0x00000000 */
-9.223372036854775808000000e+18 /* 0xC03E, 0x00000000, 0x00000000 */
};
long long int
__llrintl (long double x)
{
int32_t se,j0;
uint32_t i0, i1;
long long int result;
long double w;
long double t;
int sx;
GET_LDOUBLE_WORDS (se, i0, i1, x);
sx = (se >> 15) & 1;
j0 = (se & 0x7fff) - 0x3fff;
if (j0 < (int32_t) (8 * sizeof (long long int)) - 1)
{
if (j0 >= 63)
result = (((long long int) i0 << 32) | i1) << (j0 - 63);
else
{
#if defined FE_INVALID || defined FE_INEXACT
/* X < LLONG_MAX + 1 implied by J0 < 63. */
if (x > (long double) LLONG_MAX)
{
/* In the event of overflow we must raise the "invalid"
exception, but not "inexact". */
t = __nearbyintl (x);
feraiseexcept (t == LLONG_MAX ? FE_INEXACT : FE_INVALID);
}
else
#endif
{
w = two63[sx] + x;
t = w - two63[sx];
}
GET_LDOUBLE_WORDS (se, i0, i1, t);
j0 = (se & 0x7fff) - 0x3fff;
if (j0 < 0)
result = 0;
else if (j0 <= 31)
result = i0 >> (31 - j0);
else
result = ((long long int) i0 << (j0 - 31)) | (i1 >> (63 - j0));
}
}
else
{
/* The number is too large. It is left implementation defined
what happens. */
return (long long int) x;
}
return sx ? -result : result;
}
libm_alias_ldouble (__llrint, llrint)