1 files changed, 120 insertions, 0 deletions
diff --git a/libquadmath/math/ctanq.c b/libquadmath/math/ctanq.c
new file mode 100644
index 00000000000..d390511ca20
--- /dev/null
+++ b/libquadmath/math/ctanq.c
@@ -0,0 +1,120 @@
+/* Complex tangent function for complex __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
+ctanq (__complex128 x)
+{
+  __complex128 res;
+
+  if (__builtin_expect (!finiteq (__real__ x) || !finiteq (__imag__ x), 0))
+    {
+      if (__quadmath_isinf_nsq (__imag__ x))
+	{
+	  __real__ res = copysignq (0.0Q, __real__ x);
+	  __imag__ res = copysignq (1.0Q, __imag__ x);
+	}
+      else if (__real__ x == 0.0Q)
+	{
+	  res = x;
+	}
+      else
+	{
+	  __real__ res = nanq ("");
+	  __imag__ res = nanq ("");
+
+#ifdef HAVE_FENV_H
+	  if (__quadmath_isinf_nsq (__real__ x))
+	    feraiseexcept (FE_INVALID);
+#endif
+	}
+    }
+  else
+    {
+      __float128 sinrx, cosrx;
+      __float128 den;
+      const int t = (int) ((FLT128_MAX_EXP - 1) * M_LN2q / 2.0Q);
+      int rcls = fpclassifyq (__real__ x);
+
+      /* tan(x+iy) = (sin(2x) + i*sinh(2y))/(cos(2x) + cosh(2y))
+	 = (sin(x)*cos(x) + i*sinh(y)*cosh(y)/(cos(x)^2 + sinh(y)^2). */
+
+      if (__builtin_expect (rcls != QUADFP_SUBNORMAL, 1))
+	{
+	  sincosq (__real__ x, &sinrx, &cosrx);
+	}
+      else
+	{
+	  sinrx = __real__ x;
+	  cosrx = 1.0Q;
+	}
+
+      if (fabsq (__imag__ x) > t)
+	{
+	  /* Avoid intermediate overflow when the real part of the
+	     result may be subnormal.  Ignoring negligible terms, the
+	     imaginary part is +/- 1, the real part is
+	     sin(x)*cos(x)/sinh(y)^2 = 4*sin(x)*cos(x)/exp(2y).  */
+	  __float128 exp_2t = expq (2 * t);
+
+	  __imag__ res = copysignq (1.0Q, __imag__ x);
+	  __real__ res = 4 * sinrx * cosrx;
+	  __imag__ x = fabsq (__imag__ x);
+	  __imag__ x -= t;
+	  __real__ res /= exp_2t;
+	  if (__imag__ x > t)
+	    {
+	      /* Underflow (original imaginary part of x has absolute
+		 value > 2t).  */
+	      __real__ res /= exp_2t;
+	    }
+	  else
+	    __real__ res /= expq (2 * __imag__ x);
+	}
+      else
+	{
+	  __float128 sinhix, coshix;
+	  if (fabsq (__imag__ x) > FLT128_MIN)
+	    {
+	      sinhix = sinhq (__imag__ x);
+	      coshix = coshq (__imag__ x);
+	    }
+	  else
+	    {
+	      sinhix = __imag__ x;
+	      coshix = 1.0Q;
+	    }
+
+	  if (fabsq (sinhix) > fabsq (cosrx) * FLT128_EPSILON)
+	    den = cosrx * cosrx + sinhix * sinhix;
+	  else
+	    den = cosrx * cosrx;
+	  __real__ res = sinrx * cosrx / den;
+	  __imag__ res = sinhix * coshix / den;
+	}
+    }
+
+  return res;
+}