* sysdeps/generic/s_ctanh.c (__ctanh): Handle case of zero den better.

	* sysdeps/generic/s_ctanhf.c (__ctanhf): Likewise.
	* sysdeps/generic/s_ctanhl.c (__ctanhl): Likewise.

3 files changed, 32 insertions, 6 deletions

diff --git a/ChangeLog b/ChangeLog
index 866427fd4d..6c5daeee62 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2005-07-07  Ulrich Drepper  <drepper@redhat.com>
+
+	* sysdeps/generic/s_ctanh.c (__ctanh): Handle case of zero den better.
+	* sysdeps/generic/s_ctanhf.c (__ctanhf): Likewise.
+	* sysdeps/generic/s_ctanhl.c (__ctanhl): Likewise.
+
 2005-04-13  H.J. Lu  <hongjiu.lu@intel.com>
 
 	[BZ #974]
diff --git a/sysdeps/generic/s_ctanh.c b/sysdeps/generic/s_ctanh.c
index 971cd9040c..fe38dae291 100644
--- a/sysdeps/generic/s_ctanh.c
+++ b/sysdeps/generic/s_ctanh.c
@@ -1,5 +1,5 @@
 /* Complex hyperbole tangent for double.
-   Copyright (C) 1997 Free Software Foundation, Inc.
+   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.
 
@@ -61,8 +61,18 @@ __ctanh (__complex__ double x)
 
       den = (__ieee754_cosh (2.0 * __real__ x) + cos2ix);
 
-      __real__ res = __ieee754_sinh (2.0 * __real__ x) / den;
-      __imag__ res = sin2ix / den;
+      if (den == 0.0)
+	{
+	  __complex__ double ez = __cexp (x);
+	  __complex__ double emz = __cexp (-x);
+
+	  res = (ez - emz) / (ez + emz);
+	}
+      else
+	{
+	  __real__ res = __ieee754_sinh (2.0 * __real__ x) / den;
+	  __imag__ res = sin2ix / den;
+	}
     }
 
   return res;
diff --git a/sysdeps/generic/s_ctanhf.c b/sysdeps/generic/s_ctanhf.c
index cfcabab36a..c331dbaabb 100644
--- a/sysdeps/generic/s_ctanhf.c
+++ b/sysdeps/generic/s_ctanhf.c
@@ -1,5 +1,5 @@
 /* Complex hyperbole tangent for float.
-   Copyright (C) 1997 Free Software Foundation, Inc.
+   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.
 
@@ -61,8 +61,18 @@ __ctanhf (__complex__ float x)
 
       den = (__ieee754_coshf (2.0 * __real__ x) + cos2ix);
 
-      __real__ res = __ieee754_sinhf (2.0 * __real__ x) / den;
-      __imag__ res = sin2ix / den;
+      if (den == 0.0f)
+	{
+	  __complex__ float ez = __cexpf (x);
+	  __complex__ float emz = __cexpf (-x);
+
+	  res = (ez - emz) / (ez + emz);
+	}
+      else
+	{
+	  __real__ res = __ieee754_sinhf (2.0 * __real__ x) / den;
+	  __imag__ res = sin2ix / den;
+	}
     }
 
   return res;