1 files changed, 81 insertions, 0 deletions
diff --git a/newlib/libm/complex/catan.c b/newlib/libm/complex/catan.c
new file mode 100644
index 000000000..9e29b128e
--- /dev/null
+++ b/newlib/libm/complex/catan.c
@@ -0,0 +1,81 @@
+/* $NetBSD: catan.c,v 1.1 2007/08/20 16:01:32 drochner Exp $ */
+
+/*-
+ * Copyright (c) 2007 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software written by Stephen L. Moshier.
+ * It is redistributed by the NetBSD Foundation by permission of the author.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * imported and modified include for newlib 2010/10/03 
+ * Marco Atzeri <marco_atzeri@yahoo.it>
+ */
+
+#include <complex.h>
+#include <math.h>
+#include "cephes_subr.h"
+
+#ifdef __weak_alias
+__weak_alias(catan, _catan)
+#endif
+
+#define MAXNUM 1.0e308
+
+double complex
+catan(double complex z)
+{
+	double complex w;
+	double a, t, x, x2, y;
+
+	x = creal(z);
+	y = cimag(z);
+
+	if ((x == 0.0) && (y > 1.0))
+		goto ovrf;
+
+	x2 = x * x;
+	a = 1.0 - x2 - (y * y);
+	if (a == 0.0)
+		goto ovrf;
+
+	t = 0.5 * atan2(2.0 * x, a);
+	w = _redupi(t);
+
+	t = y - 1.0;
+	a = x2 + (t * t);
+	if (a == 0.0)
+		goto ovrf;
+
+	t = y + 1.0;
+	a = (x2 + (t * t))/a;
+	w = w + (0.25 * log(a)) * I;
+	return w;
+
+ovrf:
+#if 0
+	mtherr ("catan", OVERFLOW);
+#endif
+	w = MAXNUM + MAXNUM * I;
+	return w;
+}