1 files changed, 74 insertions, 0 deletions
diff --git a/usr/src/lib/libm/common/LD/atanhl.c b/usr/src/lib/libm/common/LD/atanhl.c
new file mode 100644
index 0000000000..d7b6d67e26
--- /dev/null
+++ b/usr/src/lib/libm/common/LD/atanhl.c
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+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
+ */
+/*
+ * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#pragma weak atanhl = __atanhl
+
+#include "libm.h"
+#include "libm_synonyms.h"
+
+#define GENERIC	long double
+#define	ATANH 	atanhl
+
+/* ATANH(x)
+ *                  1              2x                          x
+ *	ATANH(x) = --- * LOG(1 + -------) = 0.5 * LOG1P(2 * --------)
+ *                  2             1 - x                      1 - x
+ * Note: to guarantee ATANH(-x) = -ATANH(x), we use
+ *                 sign(x)             |x|  
+ *	ATANH(x) = ------- * LOG1P(2*-------).
+ *                    2              1 - |x|
+ *
+ * Special cases:
+ *	ATANH(x) is NaN if |x| > 1 with signal;
+ *	ATANH(NaN) is that NaN with no signal;
+ *	ATANH(+-1) is +-INF with signal.
+ *
+ */
+
+#define	FABS 	fabsl
+#define	LOG1P 	log1pl
+#define	COPYSIGN 	copysignl
+
+
+extern GENERIC 	FABS(),LOG1P(),COPYSIGN();
+
+static GENERIC
+zero	= (GENERIC) 0.0,
+half 	= (GENERIC) 0.5,
+one	= (GENERIC) 1.0;
+
+GENERIC ATANH(x)
+GENERIC x;
+{	
+	GENERIC t;
+	t = FABS(x);
+	if (t == one) return x/zero;
+	t = t/(one-t);
+	return COPYSIGN(half,x)*LOG1P(t+t);
+}