mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-22 13:00:06 +00:00
127 lines
3.3 KiB
C
127 lines
3.3 KiB
C
/* Round argument to nearest integral value according to current rounding
|
|
direction.
|
|
Copyright (C) 1997-2024 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
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
|
|
<https://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 int
|
|
__lrintl (long double x)
|
|
{
|
|
int32_t se,j0;
|
|
uint32_t i0, i1;
|
|
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 < 31)
|
|
{
|
|
#if defined FE_INVALID || defined FE_INEXACT
|
|
/* X < LONG_MAX + 1 implied by J0 < 31. */
|
|
if (sizeof (long int) == 4
|
|
&& x > (long double) LONG_MAX)
|
|
{
|
|
/* In the event of overflow we must raise the "invalid"
|
|
exception, but not "inexact". */
|
|
t = __nearbyintl (x);
|
|
feraiseexcept (t == LONG_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;
|
|
|
|
result = (j0 < 0 ? 0 : i0 >> (31 - j0));
|
|
}
|
|
else if (j0 < (int32_t) (8 * sizeof (long int)) - 1)
|
|
{
|
|
if (j0 >= 63)
|
|
result = ((long int) i0 << (j0 - 31)) | (i1 << (j0 - 63));
|
|
else
|
|
{
|
|
#if defined FE_INVALID || defined FE_INEXACT
|
|
/* X < LONG_MAX + 1 implied by J0 < 63. */
|
|
if (sizeof (long int) == 8
|
|
&& x > (long double) LONG_MAX)
|
|
{
|
|
/* In the event of overflow we must raise the "invalid"
|
|
exception, but not "inexact". */
|
|
t = __nearbyintl (x);
|
|
feraiseexcept (t == LONG_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 == 31)
|
|
result = (long int) i0;
|
|
else
|
|
result = ((long int) i0 << (j0 - 31)) | (i1 >> (63 - j0));
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* The number is too large. Unless it rounds to LONG_MIN,
|
|
FE_INVALID must be raised and the return value is
|
|
unspecified. */
|
|
#if defined FE_INVALID || defined FE_INEXACT
|
|
if (sizeof (long int) == 4
|
|
&& x < (long double) LONG_MIN
|
|
&& x > (long double) LONG_MIN - 1.0L)
|
|
{
|
|
/* If truncation produces LONG_MIN, the cast will not raise
|
|
the exception, but may raise "inexact". */
|
|
t = __nearbyintl (x);
|
|
feraiseexcept (t == LONG_MIN ? FE_INEXACT : FE_INVALID);
|
|
return LONG_MIN;
|
|
}
|
|
#endif
|
|
return (long int) x;
|
|
}
|
|
|
|
return sx ? -result : result;
|
|
}
|
|
|
|
libm_alias_ldouble (__lrint, lrint)
|