X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fatanl.c;h=3f8bda4c62391452acf9c48dd54ae8569510d943;hb=72c48440c1f459e2659270598b771c69e9c08994;hp=2959e0bb5cf83a44d2c862cf1c45074c5f592cc4;hpb=5657b2536d242966c41c268b9ab4fe8df727bb13;p=gnulib.git

diff --git a/lib/atanl.c b/lib/atanl.c
index 2959e0bb5..3f8bda4c6 100644
--- a/lib/atanl.c
+++ b/lib/atanl.c
@@ -1,3 +1,25 @@
+/* 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 <config.h>
+
+/* Specification.  */
+#include <math.h>
+
 /*							s_atanl.c
  *
  *	Inverse circular tangent for 128-bit long double precision
@@ -42,11 +64,7 @@
  *
  */
 
-/* Copyright 2001 by Stephen L. Moshier <moshier@na-net.ornl.gov>  */
-
-#include "mathl.h"
-
-#include <math.h>
+#include "isnanl.h"
 
 /* arctan(k/8), k = 0, ..., 82 */
 static const long double atantbl[84] = {
@@ -161,19 +179,25 @@ atanl (long double x)
   int k, sign;
   long double t, u, p, q;
 
-  sign = (x < 0) ? -1 : 1;
-
   /* Check for zero or NaN.  */
-  if (x != x || x == 0.0)
+  if (isnanl (x) || x == 0.0)
     return x + x;
 
-  /* Check for infinity.  */
+  sign = x < 0.0;
+
   if (x + x == x)
-    return sign * atantbl[83];
+    {
+      /* Infinity. */
+      if (sign)
+	return -atantbl[83];
+      else
+	return atantbl[83];
+    }
 
-  x *= sign;
+  if (sign)
+      x = -x;
 
-  if (x >= 10.25) /* 10.25 */
+  if (x >= 10.25)
     {
       k = 83;
       t = -1.0/x;
@@ -196,5 +220,9 @@ atanl (long double x)
   u = t * u * p / q  +  t;
 
   /* arctan x = arctan u  +  arctan t */
-  return sign * (atantbl[k] + u);
+  u = atantbl[k] + u;
+  if (sign)
+    return (-u);
+  else
+    return u;
 }