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diff --git a/sysdeps/libm-ieee754/s_clog.c b/sysdeps/libm-ieee754/s_clog.c
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+/* 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 Library General Public License as
+ published by the Free Software Foundation; either version 2 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
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. 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;
+
+ if (__real__ x == 0.0 && __imag__ x == 0.0)
+ {
+ __imag__ result = signbit (__real__ x) ? M_PI : 0.0;
+ if (signbit (__imag__ x))
+ __imag__ result = __copysign (__imag__ result, -1.0);
+ /* Yes, the following line raises an exception. */
+ __real__ result = -1.0 / fabs (__real__ x);
+ }
+ else if (!__isnan (__real__ x) && !__isnan (__imag__ x))
+ {
+ __real__ result = __ieee754_log (__ieee754_hypot (__real__ x,
+ __imag__ x));
+ __imag__ result = __ieee754_atan2 (__imag__ x, __real__ x);
+ }
+ else
+ {
+ __imag__ result = __nan ("");
+ if (__isinf (__real__ x) || __isinf (__imag__ x))
+ __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