mirror of
git://sourceware.org/git/glibc.git
synced 2024-12-21 04:31:04 +08:00
45 lines
1.6 KiB
C
45 lines
1.6 KiB
C
/* Compute x * y + z as ternary operation.
|
|
Copyright (C) 2011-2013 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by David Flaherty <flaherty@linux.vnet.ibm.com>.
|
|
|
|
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>
|
|
|
|
long double
|
|
__fmal (long double x, long double y, long double z)
|
|
{
|
|
/* An IBM long double 128 is really just 2 IEEE64 doubles, and in
|
|
* the case of inf/nan only the first double counts. So we use the
|
|
* (double) cast to avoid any data movement. */
|
|
if ((finite ((double)x) && finite ((double)y)) && isinf ((double)z))
|
|
return (z);
|
|
|
|
/* If z is zero and x are y are nonzero, compute the result
|
|
as x * y to avoid the wrong sign of a zero result if x * y
|
|
underflows to 0. */
|
|
if (z == 0 && x != 0 && y != 0)
|
|
return x * y;
|
|
|
|
return (x * y) + z;
|
|
}
|
|
#ifdef IS_IN_libm
|
|
long_double_symbol (libm, __fmal, fmal);
|
|
#else
|
|
long_double_symbol (libc, __fmal, fmal);
|
|
#endif
|