X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fatanl.c;h=88284a67195a329847da18f2f75a57d1a12fd30b;hb=96f023c5e537dd4afbdb294de7065f65effe3eb2;hp=16c8dc12bf0fad59fa2ac93d3687ad2e18587ab6;hpb=e1123c2f4fedae90435426a82a05cf2e3233e97d;p=gnulib.git

diff --git a/lib/atanl.c b/lib/atanl.c
index 16c8dc12b..88284a671 100644
--- a/lib/atanl.c
+++ b/lib/atanl.c
@@ -1,9 +1,9 @@
 /* Copyright 2001 by Stephen L. Moshier <moshier@na-net.ornl.gov>
 
-   This program is free software; you can redistribute it and/or modify
+   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.
+   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
@@ -11,18 +11,28 @@
    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.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <config.h>
 
 /* Specification.  */
 #include <math.h>
 
-/*							s_atanl.c
+#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)
  *
  *
@@ -64,7 +74,6 @@
  *
  */
 
-
 /* arctan(k/8), k = 0, ..., 82 */
 static const long double atantbl[84] = {
   0.0000000000000000000000000000000000000000E0L,
@@ -178,19 +187,19 @@ atanl (long double x)
   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)
@@ -204,7 +213,7 @@ atanl (long double x)
   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;
@@ -225,3 +234,5 @@ atanl (long double x)
   else
     return u;
 }
+
+#endif