* include/arpa/nameser.h: Also optimize NS_PUT16 and NS_PUT32.
[glibc.git] / math / s_clog10.c
blob62c2ca724a03cc584a22c270d465e6d0a90ff920
1 /* Compute complex base 10 logarithm.
2 Copyright (C) 1997 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, write to the Free
18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
19 02111-1307 USA. */
21 #include <complex.h>
22 #include <math.h>
24 #include "math_private.h"
27 __complex__ double
28 __clog10 (__complex__ double x)
30 __complex__ double result;
31 int rcls = fpclassify (__real__ x);
32 int icls = fpclassify (__imag__ x);
34 if (rcls == FP_ZERO && icls == FP_ZERO)
36 /* Real and imaginary part are 0.0. */
37 __imag__ result = signbit (__real__ x) ? M_PI : 0.0;
38 __imag__ result = __copysign (__imag__ result, __imag__ x);
39 /* Yes, the following line raises an exception. */
40 __real__ result = -1.0 / fabs (__real__ x);
42 else if (rcls != FP_NAN && icls != FP_NAN)
44 /* Neither real nor imaginary part is NaN. */
45 __real__ result = __ieee754_log10 (__ieee754_hypot (__real__ x,
46 __imag__ x));
47 __imag__ result = M_LOG10E * __ieee754_atan2 (__imag__ x, __real__ x);
49 else
51 __imag__ result = __nan ("");
52 if (rcls == FP_INFINITE || icls == FP_INFINITE)
53 /* Real or imaginary part is infinite. */
54 __real__ result = HUGE_VAL;
55 else
56 __real__ result = __nan ("");
59 return result;
61 weak_alias (__clog10, clog10)
62 #ifdef NO_LONG_DOUBLE
63 strong_alias (__clog10, __clog10l)
64 weak_alias (__clog10, clog10l)
65 #endif