mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-26 23:10:06 +00:00
79 lines
2.0 KiB
C
79 lines
2.0 KiB
C
/* Round double value to long int.
|
|
Copyright (C) 1997 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 Library General Public License as
|
|
published by the Free Software Foundation; either version 2 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
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with the GNU C Library; see the file COPYING.LIB. If not,
|
|
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|
Boston, MA 02111-1307, USA. */
|
|
|
|
#include <math.h>
|
|
|
|
#include "math_private.h"
|
|
|
|
|
|
long int
|
|
__lround (double x)
|
|
{
|
|
int32_t j0;
|
|
u_int32_t i1, i0;
|
|
long int result;
|
|
int sign;
|
|
|
|
EXTRACT_WORDS (i0, i1, x);
|
|
j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
|
|
sign = (i0 & 0x80000000) != 0 ? -1 : 1;
|
|
i0 &= 0xfffff;
|
|
i0 |= 0x100000;
|
|
|
|
if (j0 < 20)
|
|
{
|
|
if (j0 < 0)
|
|
return j0 < -1 ? 0 : sign;
|
|
else
|
|
{
|
|
i0 += 0x80000 >> j0;
|
|
|
|
result = i0 >> (20 - j0);
|
|
}
|
|
}
|
|
else if (j0 < (int32_t) (8 * sizeof (long int)) - 1)
|
|
{
|
|
if (j0 >= 52)
|
|
result = ((long int) i0 << (j0 - 20)) | (i1 << (j0 - 52));
|
|
else
|
|
{
|
|
u_int32_t j = i1 + (0x80000000 >> (j0 - 20));
|
|
if (j < i1)
|
|
++i0;
|
|
|
|
result = ((long int) i0 << (j0 - 20)) | (j >> (52 - j0));
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* The number is too large. It is left implementation defined
|
|
what happens. */
|
|
return (long int) x;
|
|
}
|
|
|
|
return sign * result;
|
|
}
|
|
|
|
weak_alias (__lround, lround)
|
|
#ifdef NO_LONG_DOUBLE
|
|
strong_alias (__lround, __lroundl)
|
|
weak_alias (__lround, lroundl)
|
|
#endif
|