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/* 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)))
{
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
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