blob: 30ea5db7ccbf9f16fe46958833336698193d8089 [file] [log] [blame]
/* Round double value to long int.
Copyright (C) 1997, 2004, 2009 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. */
#define llround __hidden_llround
#define __llround __hidden___llround
#include <math.h>
#include "math_private.h"
long int
__lround (double x)
{
int32_t j0;
int64_t i0;
long int result;
int sign;
EXTRACT_WORDS64 (i0, x);
j0 = ((i0 >> 52) & 0x7ff) - 0x3ff;
sign = i0 < 0 ? -1 : 1;
i0 &= UINT64_C(0xfffffffffffff);
i0 |= UINT64_C(0x10000000000000);
if (j0 < (int32_t) (8 * sizeof (long int)) - 1)
{
if (j0 < 0)
return j0 < -1 ? 0 : sign;
else if (j0 >= 52)
result = i0 << (j0 - 52);
else
{
i0 += UINT64_C(0x8000000000000) >> j0;
result = i0 >> (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
/* long long has the same width as long on 64-bit machines. */
#undef llround
#undef __llround
strong_alias (__lround, __llround)
weak_alias (__lround, llround)
#ifdef NO_LONG_DOUBLE
strong_alias (__lround, __llroundl)
weak_alias (__lround, llroundl)
#endif