1 files changed, 65 insertions, 0 deletions
diff --git a/math/s_clog.c b/math/s_clog.c
new file mode 100644
index 0000000000..f796024b47
--- /dev/null
+++ b/math/s_clog.c
@@ -0,0 +1,65 @@
+/* Compute complex natural logarithm.
+   Copyright (C) 1997 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>
+
+#include "math_private.h"
+
+
+__complex__ double
+__clog (__complex__ double x)
+{
+  __complex__ double result;
+  int rcls = fpclassify (__real__ x);
+  int icls = fpclassify (__imag__ x);
+
+  if (rcls == FP_ZERO && icls == FP_ZERO)
+    {
+      /* Real and imaginary part are 0.0.  */
+      __imag__ result = signbit (__real__ x) ? M_PI : 0.0;
+      __imag__ result = __copysign (__imag__ result, __imag__ x);
+      /* Yes, the following line raises an exception.  */
+      __real__ result = -1.0 / fabs (__real__ x);
+    }
+  else if (rcls != FP_NAN && icls != FP_NAN)
+    {
+      /* Neither real nor imaginary part is NaN.  */
+      __real__ result = __ieee754_log (__ieee754_hypot (__real__ x,
+							__imag__ x));
+      __imag__ result = __ieee754_atan2 (__imag__ x, __real__ x);
+    }
+  else
+    {
+      __imag__ result = __nan ("");
+      if (rcls == FP_INFINITE || icls == FP_INFINITE)
+	/* Real or imaginary part is infinite.  */
+	__real__ result = HUGE_VAL;
+      else
+	__real__ result = __nan ("");
+    }
+
+  return result;
+}
+weak_alias (__clog, clog)
+#ifdef NO_LONG_DOUBLE
+strong_alias (__clog, __clogl)
+weak_alias (__clog, clogl)
+#endif