--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libquadmath/math/ctanhq.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,120 @@
+/* Complex hyperbole tangent for __float128.
+   Copyright (C) 1997-2012 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include "quadmath-imp.h"
+
+#ifdef HAVE_FENV_H
+# include <fenv.h>
+#endif
+
+
+__complex128
+ctanhq (__complex128 x)
+{
+  __complex128 res;
+
+  if (__builtin_expect (!finiteq (__real__ x) || !finiteq (__imag__ x), 0))
+    {
+      if (__quadmath_isinf_nsq (__real__ x))
+	{
+	  __real__ res = copysignq (1.0Q, __real__ x);
+	  __imag__ res = copysignq (0.0Q, __imag__ x);
+	}
+      else if (__imag__ x == 0.0Q)
+	{
+	  res = x;
+	}
+      else
+	{
+	  __real__ res = nanq ("");
+	  __imag__ res = nanq ("");
+
+#ifdef HAVE_FENV_H
+	  if (__quadmath_isinf_nsq (__imag__ x))
+	    feraiseexcept (FE_INVALID);
+#endif
+	}
+    }
+  else
+    {
+      __float128 sinix, cosix;
+      __float128 den;
+      const int t = (int) ((FLT128_MAX_EXP - 1) * M_LN2q / 2);
+      int icls = fpclassifyq (__imag__ x);
+
+      /* tanh(x+iy) = (sinh(2x) + i*sin(2y))/(cosh(2x) + cos(2y))
+	 = (sinh(x)*cosh(x) + i*sin(y)*cos(y))/(sinh(x)^2 + cos(y)^2).  */
+
+      if (__builtin_expect (icls != QUADFP_SUBNORMAL, 1))
+	{
+	  sincosq (__imag__ x, &sinix, &cosix);
+	}
+      else
+	{
+	  sinix = __imag__ x;
+	  cosix = 1.0Q;
+	}
+
+      if (fabsq (__real__ x) > t)
+	{
+	  /* Avoid intermediate overflow when the imaginary part of
+	     the result may be subnormal.  Ignoring negligible terms,
+	     the real part is +/- 1, the imaginary part is
+	     sin(y)*cos(y)/sinh(x)^2 = 4*sin(y)*cos(y)/exp(2x).  */
+	  __float128 exp_2t = expq (2 * t);
+
+	  __real__ res = copysignq (1.0, __real__ x);
+	  __imag__ res = 4 * sinix * cosix;
+	  __real__ x = fabsq (__real__ x);
+	  __real__ x -= t;
+	  __imag__ res /= exp_2t;
+	  if (__real__ x > t)
+	    {
+	      /* Underflow (original real part of x has absolute value
+		 > 2t).  */
+	      __imag__ res /= exp_2t;
+	    }
+	  else
+	    __imag__ res /= expq (2 * __real__ x);
+	}
+      else
+	{
+	  __float128 sinhrx, coshrx;
+	  if (fabsq (__real__ x) > FLT128_MIN)
+	    {
+	      sinhrx = sinhq (__real__ x);
+	      coshrx = coshq (__real__ x);
+	    }
+	  else
+	    {
+	      sinhrx = __real__ x;
+	      coshrx = 1.0Q;
+	    }
+
+	  if (fabsq (sinhrx) > fabsq (cosix) * FLT128_EPSILON)
+	    den = sinhrx * sinhrx + cosix * cosix;
+	  else
+	    den = cosix * cosix;
+	  __real__ res = sinhrx * coshrx / den;
+	  __imag__ res = sinix * cosix / den;
+	}
+    }
+
+  return res;
+}