1 files changed, 90 insertions, 0 deletions
diff --git a/usr/src/lib/libm/common/C/cosh.c b/usr/src/lib/libm/common/C/cosh.c
new file mode 100644
index 0000000000..91573149e6
--- /dev/null
+++ b/usr/src/lib/libm/common/C/cosh.c
@@ -0,0 +1,90 @@
+/*
+ * 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 2005 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#pragma weak cosh = __cosh
+
+/* INDENT OFF */
+/*
+ * cosh(x)
+ * Code originated from 4.3bsd.
+ * Modified by K.C. Ng for SUN 4.0 libm.
+ * Method :
+ *	1. Replace x by |x| (cosh(x) = cosh(-x)).
+ *	2.
+ *                                       [ exp(x) - 1 ]^2
+ *  0        <= x <= 0.3465  :  cosh(x) := 1 + -------------------
+ *								      2*exp(x)
+ *
+ *		                                   exp(x) +  1/exp(x)
+ *  0.3465   <= x <= 22      :  cosh(x) := -------------------
+ *								           2
+ *  22       <= x <= lnovft  :  cosh(x) := exp(x)/2
+ *  lnovft   <= x <  INF     :  cosh(x) := scalbn(exp(x-1024*ln2),1023)
+ *
+ *	Note: .3465 is a number near one half of ln2.
+ *
+ * Special cases:
+ *	cosh(x) is |x| if x is +INF, -INF, or NaN.
+ *	only cosh(0)=1 is exact for finite x.
+ */
+/* INDENT ON */
+
+#include "libm.h"
+
+static const double
+	ln2 = 6.93147180559945286227e-01,
+	ln2hi = 6.93147180369123816490e-01,
+	ln2lo = 1.90821492927058770002e-10,
+	lnovft = 7.09782712893383973096e+02;
+
+double
+cosh(double x) {
+	double t, w;
+
+	w = fabs(x);
+	if (!finite(w))
+		return (w * w);
+	if (w < 0.3465) {
+		t = expm1(w);
+		w = 1.0 + t;
+		if (w != 1.0)
+			w = 1.0 + (t * t) / (w + w);
+		return (w);
+	} else if (w < 22.0) {
+		t = exp(w);
+		return (0.5 * (t + 1.0 / t));
+	} else if (w <= lnovft) {
+		return (0.5 * exp(w));
+	} else {
+		w = (w - 1024 * ln2hi) - 1024 * ln2lo;
+		if (w >= ln2)
+			return (_SVID_libm_err(x, x, 5));
+		else
+			return (scalbn(exp(w), 1023));
+	}
+}