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diff --git a/math/s_clog10.c b/math/s_clog10.c
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+/* Compute complex base 10 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
+__clog10 (__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_log10 (__ieee754_hypot (__real__ x,
+ __imag__ x));
+ __imag__ result = M_LOG10E * __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 (__clog10, clog10)
+#ifdef NO_LONG_DOUBLE
+strong_alias (__clog10, __clog10l)
+weak_alias (__clog10, clog10l)
+#endif