glibc/sysdeps/ieee754/ldbl-128ibm/s_truncl.c

63 lines
1.7 KiB
C

/* Truncate (toward zero) 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/>. */
#include <math.h>
#include <math_ldbl_opt.h>
#include <float.h>
#include <ieee754.h>
long double
__truncl (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 = __trunc (xh);
if (hi != xh)
{
/* The high part is not an integer; the low part does not
affect the result. */
xh = hi;
xl = 0;
}
else
{
/* The high part is a nonzero integer. */
lo = xh > 0 ? __floor (xl) : __ceil (xl);
xh = hi;
xl = lo;
ldbl_canonicalize_int (&xh, &xl);
}
}
else
/* Quiet signaling NaN arguments. */
xh += xh;
return ldbl_pack (xh, xl);
}
long_double_symbol (libm, __truncl, truncl);