mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-26 12:41:05 +00:00
88 lines
2.2 KiB
C
88 lines
2.2 KiB
C
/* Round to int long double floating-point values.
|
|
IBM extended format long double version.
|
|
Copyright (C) 2006-2017 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
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/>. */
|
|
|
|
/* This has been coded in assembler because GCC makes such a mess of it
|
|
when it's coded in C. */
|
|
|
|
#include <math.h>
|
|
#include <math_ldbl_opt.h>
|
|
#include <float.h>
|
|
#include <ieee754.h>
|
|
|
|
|
|
long double
|
|
__roundl (long double x)
|
|
{
|
|
double xh, xl, hi, lo;
|
|
|
|
ldbl_unpack (x, &xh, &xl);
|
|
|
|
/* Return Inf, Nan, +/-0 unchanged. */
|
|
if (__builtin_expect (xh != 0.0
|
|
&& __builtin_isless (__builtin_fabs (xh),
|
|
__builtin_inf ()), 1))
|
|
{
|
|
hi = __round (xh);
|
|
if (hi != xh)
|
|
{
|
|
/* The high part is not an integer; the low part only
|
|
affects the result if the high part is exactly half way
|
|
between two integers and the low part is nonzero with the
|
|
opposite sign. */
|
|
if (fabs (hi - xh) == 0.5)
|
|
{
|
|
if (xh > 0 && xl < 0)
|
|
xh = hi - 1;
|
|
else if (xh < 0 && xl > 0)
|
|
xh = hi + 1;
|
|
else
|
|
xh = hi;
|
|
}
|
|
else
|
|
xh = hi;
|
|
xl = 0;
|
|
}
|
|
else
|
|
{
|
|
/* The high part is a nonzero integer. */
|
|
lo = __round (xl);
|
|
if (fabs (lo - xl) == 0.5)
|
|
{
|
|
if (xh > 0 && xl < 0)
|
|
xl = lo + 1;
|
|
else if (xh < 0 && lo > 0)
|
|
xl = lo - 1;
|
|
else
|
|
xl = lo;
|
|
}
|
|
else
|
|
xl = lo;
|
|
xh = hi;
|
|
ldbl_canonicalize_int (&xh, &xl);
|
|
}
|
|
}
|
|
else
|
|
/* Quiet signaling NaN arguments. */
|
|
xh += xh;
|
|
|
|
return ldbl_pack (xh, xl);
|
|
}
|
|
|
|
long_double_symbol (libm, __roundl, roundl);
|