1 files changed, 66 insertions, 0 deletions
diff --git a/src/complex/ctanhf.c b/src/complex/ctanhf.c
new file mode 100644
index 00000000..7d746134
--- /dev/null
+++ b/src/complex/ctanhf.c
@@ -0,0 +1,66 @@
+/* origin: FreeBSD /usr/src/lib/msun/src/s_ctanhf.c */
+/*-
+ * Copyright (c) 2011 David Schultz
+ * All rights reserved.
+ *
+ * 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 unmodified, 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 AUTHOR ``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 AUTHOR 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.
+ */
+/*
+ * Hyperbolic tangent of a complex argument z.  See s_ctanh.c for details.
+ */
+
+#include "libm.h"
+
+float complex ctanhf(float complex z)
+{
+	float x, y;
+	float t, beta, s, rho, denom;
+	uint32_t hx, ix;
+
+	x = crealf(z);
+	y = cimagf(z);
+
+	GET_FLOAT_WORD(hx, x);
+	ix = hx & 0x7fffffff;
+
+	if (ix >= 0x7f800000) {
+		if (ix & 0x7fffff)
+			return cpackf(x, (y == 0 ? y : x * y));
+		SET_FLOAT_WORD(x, hx - 0x40000000);
+		return cpackf(x, copysignf(0, isinf(y) ? y : sinf(y) * cosf(y)));
+	}
+
+	if (!isfinite(y))
+		return cpackf(y - y, y - y);
+
+	if (ix >= 0x41300000) { /* x >= 11 */
+		float exp_mx = expf(-fabsf(x));
+		return cpackf(copysignf(1, x), 4 * sinf(y) * cosf(y) * exp_mx * exp_mx);
+	}
+
+	t = tanf(y);
+	beta = 1.0 + t * t;
+	s = sinhf(x);
+	rho = sqrtf(1 + s * s);
+	denom = 1 + beta * s * s;
+	return cpackf((beta * rho * s) / denom, t / denom);
+}