mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-26 20:51:11 +00:00
101 lines
2.2 KiB
C
101 lines
2.2 KiB
C
/* Round long double to integer away from zero.
|
|
Copyright (C) 1997, 2007, 2011 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 <math.h>
|
|
|
|
#include <math_private.h>
|
|
|
|
|
|
static const long double huge = 1.0e4930L;
|
|
|
|
|
|
long double
|
|
__roundl (long double x)
|
|
{
|
|
int32_t j0;
|
|
u_int32_t se, i1, i0;
|
|
|
|
GET_LDOUBLE_WORDS (se, i0, i1, x);
|
|
j0 = (se & 0x7fff) - 0x3fff;
|
|
if (j0 < 31)
|
|
{
|
|
if (j0 < 0)
|
|
{
|
|
math_force_eval (huge + x);
|
|
se &= 0x8000;
|
|
i0 = i1 = 0;
|
|
if (j0 == -1)
|
|
{
|
|
se |= 0x3fff;
|
|
i0 = 0x80000000;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
u_int32_t i = 0x7fffffff >> j0;
|
|
if (((i0 & i) | i1) == 0)
|
|
/* X is integral. */
|
|
return x;
|
|
|
|
/* Raise inexact if x != 0. */
|
|
math_force_eval (huge + x);
|
|
u_int32_t j = i0 + (0x40000000 >> j0);
|
|
if (j < i0)
|
|
se += 1;
|
|
i0 = (j & ~i) | 0x80000000;
|
|
i1 = 0;
|
|
}
|
|
}
|
|
else if (j0 > 62)
|
|
{
|
|
if (j0 == 0x4000)
|
|
/* Inf or NaN. */
|
|
return x + x;
|
|
else
|
|
return x;
|
|
}
|
|
else
|
|
{
|
|
u_int32_t i = 0xffffffff >> (j0 - 31);
|
|
if ((i1 & i) == 0)
|
|
/* X is integral. */
|
|
return x;
|
|
|
|
math_force_eval (huge + x);
|
|
/* Raise inexact if x != 0. */
|
|
u_int32_t j = i1 + (1 << (62 - j0));
|
|
if (j < i1)
|
|
{
|
|
u_int32_t k = i0 + 1;
|
|
if (k < i0)
|
|
{
|
|
se += 1;
|
|
k |= 0x80000000;
|
|
}
|
|
i0 = k;
|
|
}
|
|
i1 = j;
|
|
i1 &= ~i;
|
|
}
|
|
|
|
SET_LDOUBLE_WORDS (x, se, i0, i1);
|
|
return x;
|
|
}
|
|
weak_alias (__roundl, roundl)
|