--- /dev/null	Sat May 10 12:09:23 2014
+++ new/usr/src/lib/libm/common/complex/ctanh.c	Sat May 10 12:09:23 2014
@@ -0,0 +1,176 @@
+/*
+ * 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 ctanh = __ctanh
+
+/* INDENT OFF */
+/*
+ * dcomplex ctanh(dcomplex z);
+ *
+ *            tanh x  + i tan y      sinh 2x  +  i sin 2y
+ * ctanh z = --------------------- = --------------------
+ *           1 + i tanh(x)tan(y)       cosh 2x + cos 2y
+ *
+ * For |x| >= prec/2 (14,28,34,60 for single, double, double extended, quad),
+ * we use
+ *
+ *                         1   2x                              2 sin 2y
+ *    cosh 2x = sinh 2x = --- e    and hence  ctanh z = 1 + i -----------;
+ *                         2                                       2x
+ *                                                                e
+ *
+ * otherwise, to avoid cancellation, for |x| < prec/2,
+ *                              2x     2
+ *                            (e   - 1)        2       2
+ *    cosh 2x + cos 2y = 1 + ------------ + cos y - sin y
+ *                                 2x
+ *                              2 e
+ *
+ *                        1    2x     2  -2x         2
+ *                     = --- (e   - 1)  e     + 2 cos y
+ *                        2
+ * and
+ *
+ *                  [            2x      ]
+ *               1  [  2x       e   - 1  ]
+ *    sinh 2x = --- [ e  - 1 + --------- ]
+ *               2  [               2x   ]
+ *                  [              e     ]
+ *                                             2x
+ * Implementation notes:  let t = expm1(2x) = e   - 1, then
+ *
+ *                     1    [  t*t         2  ]              1    [      t  ]
+ * cosh 2x + cos 2y = --- * [ ----- + 4 cos y ];  sinh 2x = --- * [ t + --- ]
+ *                     2    [  t+1            ]              2    [     t+1 ]
+ *
+ * Hence,
+ *
+ *
+ *                        t*t+2t                  [4(t+1)(cos y)]*(sin y)
+ *    ctanh z = --------------------------- + i --------------------------
+ *               t*t+[4(t+1)(cos y)](cos y)     t*t+[4(t+1)(cos y)](cos y)
+ *
+ * EXCEPTION (conform to ISO/IEC 9899:1999(E)):
+ *      ctanh(0,0)=(0,0)
+ *      ctanh(x,inf) = (NaN,NaN) for finite x
+ *      ctanh(x,NaN) = (NaN,NaN) for finite x
+ *      ctanh(inf,y) = 1+ i*0*sin(2y) for positive-signed finite y
+ *      ctanh(inf,inf) = (1, +-0)
+ *      ctanh(inf,NaN) = (1, +-0)
+ *      ctanh(NaN,0) = (NaN,0)
+ *      ctanh(NaN,y) = (NaN,NaN) for non-zero y
+ *      ctanh(NaN,NaN) = (NaN,NaN)
+ */
+/* INDENT ON */
+
+#include "libm.h"		/* exp/expm1/fabs/sin/tanh/sincos */
+#include "complex_wrapper.h"
+
+static const double four = 4.0, two = 2.0, one = 1.0, zero = 0.0;
+
+dcomplex
+ctanh(dcomplex z) {
+	double t, r, v, u, x, y, S, C;
+	int hx, ix, lx, hy, iy, ly;
+	dcomplex ans;
+
+	x = D_RE(z);
+	y = D_IM(z);
+	hx = HI_WORD(x);
+	lx = LO_WORD(x);
+	ix = hx & 0x7fffffff;
+	hy = HI_WORD(y);
+	ly = LO_WORD(y);
+	iy = hy & 0x7fffffff;
+	x = fabs(x);
+	y = fabs(y);
+
+	if ((iy | ly) == 0) {	/* ctanh(x,0) = (x,0) for x = 0 or NaN */
+		D_RE(ans) = tanh(x);
+		D_IM(ans) = zero;
+	} else if (iy >= 0x7ff00000) {	/* y is inf or NaN */
+		if (ix < 0x7ff00000)	/* catanh(finite x,inf/nan) is nan */
+			D_RE(ans) = D_IM(ans) = y - y;
+		else if (((ix - 0x7ff00000) | lx) == 0) {	/* x is inf */
+			D_RE(ans) = one;
+			D_IM(ans) = zero;
+		} else {
+			D_RE(ans) = x + y;
+			D_IM(ans) = y - y;
+		}
+	} else if (ix >= 0x403c0000) {
+		/*
+		 * |x| > 28 = prec/2 (14,28,34,60)
+		 * ctanh z ~ 1 + i (sin2y)/(exp(2x))
+		 */
+		D_RE(ans) = one;
+		if (iy < 0x7fe00000)	/* t = sin(2y) */
+			S = sin(y + y);
+		else {
+			(void) sincos(y, &S, &C);
+			S = (S + S) * C;
+		}
+		if (ix >= 0x7fe00000) {	/* |x| > max/2 */
+			if (ix >= 0x7ff00000) {	/* |x| is inf or NaN */
+				if (((ix - 0x7ff00000) | lx) != 0)
+					D_RE(ans) = D_IM(ans) = x + y;
+								/* x is NaN */
+				else
+					D_IM(ans) = zero * S;	/* x is inf */
+			} else
+				D_IM(ans) = S * exp(-x);	/* underflow */
+		} else
+			D_IM(ans) = (S + S) * exp(-(x + x));
+							/* 2 sin 2y / exp(2x) */
+	} else {
+		/* INDENT OFF */
+		/*
+		 *                        t*t+2t
+		 *    ctanh z = --------------------------- +
+		 *               t*t+[4(t+1)(cos y)](cos y)
+		 *
+		 *                  [4(t+1)(cos y)]*(sin y)
+		 *              i --------------------------
+		 *                t*t+[4(t+1)(cos y)](cos y)
+		 */
+		/* INDENT ON */
+		(void) sincos(y, &S, &C);
+		t = expm1(x + x);
+		r = (four * C) * (t + one);
+		u = t * t;
+		v = one / (u + r * C);
+		D_RE(ans) = (u + two * t) * v;
+		D_IM(ans) = (r * S) * v;
+	}
+	if (hx < 0)
+		D_RE(ans) = -D_RE(ans);
+	if (hy < 0)
+		D_IM(ans) = -D_IM(ans);
+	return (ans);
+}
