-/* s_atanl.c
+/* Copyright 2001 by Stephen L. Moshier <moshier@na-net.ornl.gov>
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program 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 General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include <config.h>
+
+/* Specification. */
+#include <math.h>
+
+#if HAVE_SAME_LONG_DOUBLE_AS_DOUBLE
+
+long double
+atanl (long double x)
+{
+ return atan (x);
+}
+
+#else
+
+/* Code based on glibc/sysdeps/ieee754/ldbl-128/s_atanl.c. */
+
+/* s_atanl.c
*
- * Inverse circular tangent for 128-bit long double precision
+ * Inverse circular tangent for 128-bit long double precision
* (arctangent)
*
*
*
*/
-/* Copyright 2001 by Stephen L. Moshier <moshier@na-net.ornl.gov>
-
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2, or (at your option)
- any later version.
-
- This program 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 General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program; see the file COPYING.
- If not, write to the Free Software Foundation,
- 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
-
-#include "mathl.h"
-
-#include <math.h>
-
/* arctan(k/8), k = 0, ..., 82 */
static const long double atantbl[84] = {
0.0000000000000000000000000000000000000000E0L,
int k, sign;
long double t, u, p, q;
- sign = x < 0.0;
-
/* Check for zero or NaN. */
- if (x != x || x == 0.0)
+ if (isnanl (x) || x == 0.0)
return x + x;
+ sign = x < 0.0;
+
if (x + x == x)
{
/* Infinity. */
if (sign)
- return -atantbl[83];
+ return -atantbl[83];
else
- return atantbl[83];
+ return atantbl[83];
}
if (sign)
else
{
/* Index of nearest table element.
- Roundoff to integer is asymmetrical to avoid cancellation when t < 0
+ Roundoff to integer is asymmetrical to avoid cancellation when t < 0
(cf. fdlibm). */
k = 8.0 * x + 0.25;
u = 0.125 * k;
else
return u;
}
+
+#endif