1 files changed, 95 insertions, 0 deletions
diff --git a/math/s_cacosh.c b/math/s_cacosh.c
new file mode 100644
index 0000000..ada7ca5
--- /dev/null
+++ b/math/s_cacosh.c
@@ -0,0 +1,95 @@
+/* Return arc hyperbole cosine for double value.
+   Copyright (C) 1997, 2006 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 <math.h>
+
+
+__complex__ double
+__cacosh (__complex__ double x)
+{
+  __complex__ double res;
+  int rcls = fpclassify (__real__ x);
+  int icls = fpclassify (__imag__ x);
+
+  if (rcls <= FP_INFINITE || icls <= FP_INFINITE)
+    {
+      if (icls == FP_INFINITE)
+	{
+	  __real__ res = HUGE_VAL;
+
+	  if (rcls == FP_NAN)
+	    __imag__ res = __nan ("");
+	  else
+	    __imag__ res = __copysign ((rcls == FP_INFINITE
+					? (__real__ x < 0.0
+					   ? M_PI - M_PI_4 : M_PI_4)
+					: M_PI_2), __imag__ x);
+	}
+      else if (rcls == FP_INFINITE)
+	{
+	  __real__ res = HUGE_VAL;
+
+	  if (icls >= FP_ZERO)
+	    __imag__ res = __copysign (signbit (__real__ x) ? M_PI : 0.0,
+				       __imag__ x);
+	  else
+	    __imag__ res = __nan ("");
+	}
+      else
+	{
+	  __real__ res = __nan ("");
+	  __imag__ res = __nan ("");
+	}
+    }
+  else if (rcls == FP_ZERO && icls == FP_ZERO)
+    {
+      __real__ res = 0.0;
+      __imag__ res = __copysign (M_PI_2, __imag__ x);
+    }
+  else
+    {
+      __complex__ double y;
+
+      __real__ y = (__real__ x - __imag__ x) * (__real__ x + __imag__ x) - 1.0;
+      __imag__ y = 2.0 * __real__ x * __imag__ x;
+
+      y = __csqrt (y);
+
+      if (__real__ x < 0.0)
+	y = -y;
+
+      __real__ y += __real__ x;
+      __imag__ y += __imag__ x;
+
+      res = __clog (y);
+
+      /* We have to use the positive branch.  */
+      if (__real__ res < 0.0)
+	res = -res;
+    }
+
+  return res;
+}
+weak_alias (__cacosh, cacosh)
+#ifdef NO_LONG_DOUBLE
+strong_alias (__cacosh, __cacoshl)
+weak_alias (__cacosh, cacoshl)
+#endif