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+/* Complex tangent function for long double.
+ Copyright (C) 1997, 2005 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <complex.h>
+#include <fenv.h>
+#include <math.h>
+
+#include "math_private.h"
+
+
+__complex__ long double
+__ctanl (__complex__ long double x)
+{
+ __complex__ long double res;
+
+ if (!isfinite (__real__ x) || !isfinite (__imag__ x))
+ {
+ if (__isinfl (__imag__ x))
+ {
+ __real__ res = __copysignl (0.0, __real__ x);
+ __imag__ res = __copysignl (1.0, __imag__ x);
+ }
+ else if (__real__ x == 0.0)
+ {
+ res = x;
+ }
+ else
+ {
+ __real__ res = __nanl ("");
+ __imag__ res = __nanl ("");
+
+#ifdef FE_INVALID
+ if (__isinfl (__real__ x))
+ feraiseexcept (FE_INVALID);
+#endif
+ }
+ }
+ else
+ {
+ long double sin2rx, cos2rx;
+ long double den;
+
+ __sincosl (2.0 * __real__ x, &sin2rx, &cos2rx);
+
+ den = cos2rx + __ieee754_coshl (2.0 * __imag__ x);
+
+
+ if (den == 0.0)
+ {
+ __complex__ long double ez = __cexpl (1.0i * x);
+ __complex__ long double emz = __cexpl (-1.0i * x);
+
+ res = (ez - emz) / (ez + emz) * -1.0i;
+ }
+ else
+ {
+ __real__ res = sin2rx / den;
+ __imag__ res = __ieee754_sinhl (2.0 * __imag__ x) / den;
+ }
+ }
+
+ return res;
+}
+weak_alias (__ctanl, ctanl)