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/* Round double value to long int.
Copyright (C) 1997, 2004 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <math.h>
#include "math_private.h"
libm_hidden_proto(lround)
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;
if (j0 == 20)
result = (long int) i0;
else
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;
}
libm_hidden_def(lround)
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