Update.
[glibc.git] / sysdeps / libm-ieee754 / s_clog10f.c
blobbc4094b8baf68ead8107a084b82c33d0a378d049
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 Library General Public License as
8 published by the Free Software Foundation; either version 2 of the
9 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 Library General Public License for more details.
16 You should have received a copy of the GNU Library General Public
17 License along with the GNU C Library; see the file COPYING.LIB. If not,
18 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
21 #include <complex.h>
22 #include <math.h>
24 #include "math_private.h"
27 __complex__ float
28 __clog10f (__complex__ float x)
30 __complex__ float 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 = __copysignf (__imag__ result, __imag__ x);
39 /* Yes, the following line raises an exception. */
40 __real__ result = -1.0 / fabsf (__real__ x);
42 else if (rcls != FP_NAN && icls != FP_NAN)
44 /* Neither real nor imaginary part is NaN. */
45 __real__ result = __ieee754_log10f (__ieee754_hypotf (__real__ x,
46 __imag__ x));
47 __imag__ result = M_LOG10E * __ieee754_atan2f (__imag__ x, __real__ x);
49 else
51 __imag__ result = __nanf ("");
52 if (rcls == FP_INFINITE || icls == FP_INFINITE)
53 /* Real or imaginary part is infinite. */
54 __real__ result = HUGE_VALF;
55 else
56 __real__ result = __nanf ("");
59 return result;
61 weak_alias (__clog10f, clog10f)