1 files changed, 83 insertions, 0 deletions
diff --git a/newlib/libm/mathfp/s_atan.c b/newlib/libm/mathfp/s_atan.c
new file mode 100644
index 00000000000..b8e633e3dfb
--- /dev/null
+++ b/newlib/libm/mathfp/s_atan.c
@@ -0,0 +1,83 @@
+
+/* @(#)z_atan.c 1.0 98/08/13 */
+
+/*
+FUNCTION
+        <<atan>>, <<atanf>>---arc tangent
+
+INDEX
+   atan
+INDEX
+   atanf
+
+ANSI_SYNOPSIS
+        #include <math.h>
+        double atan(double <[x]>);
+        float atanf(float <[x]>);
+
+TRAD_SYNOPSIS
+        #include <math.h>
+        double atan(<[x]>);
+        double <[x]>;
+
+        float atanf(<[x]>);
+        float <[x]>;
+
+DESCRIPTION
+
+<<atan>> computes the inverse tangent (arc tangent) of the input value.
+
+<<atanf>> is identical to <<atan>>, save that it operates on <<floats>>.
+
+RETURNS
+@ifinfo
+<<atan>> returns a value in radians, in the range of -pi/2 to pi/2.
+@end ifinfo
+@tex
+<<atan>> returns a value in radians, in the range of $-\pi/2$ to $\pi/2$.
+@end tex
+
+PORTABILITY
+<<atan>> is ANSI C.  <<atanf>> is an extension.
+
+*/
+
+/******************************************************************
+ * Arctangent
+ *
+ * Input:
+ *   x - floating point value
+ *
+ * Output:
+ *   arctan of x
+ *
+ * Description:
+ *   This routine returns the arctan of x.
+ *
+ *****************************************************************/
+
+#include "fdlibm.h"
+#include "zmath.h"
+
+#ifndef _DOUBLE_IS_32BITS
+
+double
+_DEFUN (atan, (double),
+        double x)
+{
+  switch (numtest (x))
+    {
+      case NAN:
+        errno = EDOM;
+        return (x);
+      case INF:
+        /* this should check to see if neg NaN or pos NaN... */
+        return (__PI_OVER_TWO);
+      case 0:
+        return (0.0);
+      default:
+        return (atangent (x, 0, 0, 0));
+    }
+}
+
+#endif /* _DOUBLE_IS_32BITS */