mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-23 13:30:06 +00:00
688903eb3e
* All files with FSF copyright notices: Update copyright dates using scripts/update-copyrights. * locale/programs/charmap-kw.h: Regenerated. * locale/programs/locfile-kw.h: Likewise.
111 lines
2.7 KiB
C
111 lines
2.7 KiB
C
/* Round double value to long int.
|
|
Copyright (C) 1997-2018 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 <fenv.h>
|
|
#include <limits.h>
|
|
#include <math.h>
|
|
|
|
#include <math_private.h>
|
|
#include <libm-alias-double.h>
|
|
#include <fix-fp-int-convert-overflow.h>
|
|
|
|
|
|
long int
|
|
__lround (double x)
|
|
{
|
|
int32_t j0;
|
|
uint32_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)) | ((long int) i1 << (j0 - 52));
|
|
else
|
|
{
|
|
uint32_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));
|
|
#ifdef FE_INVALID
|
|
if (sizeof (long int) == 4
|
|
&& sign == 1
|
|
&& result == LONG_MIN)
|
|
/* Rounding brought the value out of range. */
|
|
feraiseexcept (FE_INVALID);
|
|
#endif
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* The number is too large. Unless it rounds to LONG_MIN,
|
|
FE_INVALID must be raised and the return value is
|
|
unspecified. */
|
|
#ifdef FE_INVALID
|
|
if (FIX_DBL_LONG_CONVERT_OVERFLOW
|
|
&& !(sign == -1
|
|
&& (sizeof (long int) == 4
|
|
? x > (double) LONG_MIN - 0.5
|
|
: x >= (double) LONG_MIN)))
|
|
{
|
|
feraiseexcept (FE_INVALID);
|
|
return sign == 1 ? LONG_MAX : LONG_MIN;
|
|
}
|
|
else if (!FIX_DBL_LONG_CONVERT_OVERFLOW
|
|
&& sizeof (long int) == 4
|
|
&& x <= (double) LONG_MIN - 0.5)
|
|
{
|
|
/* If truncation produces LONG_MIN, the cast will not raise
|
|
the exception, but may raise "inexact". */
|
|
feraiseexcept (FE_INVALID);
|
|
return LONG_MIN;
|
|
}
|
|
#endif
|
|
return (long int) x;
|
|
}
|
|
|
|
return sign * result;
|
|
}
|
|
|
|
libm_alias_double (__lround, lround)
|