projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| dfd2257a UD |
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. | |
| 5 | ||
| 6 | The GNU C Library is free software; you can redistribute it and/or | |
| 41bdb6e2 AJ |
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. | |
| dfd2257a UD |
10 | |
| 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 | |
| 41bdb6e2 | 14 | Lesser General Public License for more details. |
| dfd2257a | 15 | |
| 41bdb6e2 AJ |
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. */ | |
| dfd2257a UD |
20 | |
| 21 | #include <complex.h> | |
| 22 | #include <math.h> | |
| 23 | ||
| 24 | #include "math_private.h" | |
| 25 | ||
| 26 | ||
| 27 | __complex__ double | |
| 28 | __clog10 (__complex__ double x) | |
| 29 | { | |
| 30 | __complex__ double result; | |
| 31 | int rcls = fpclassify (__real__ x); | |
| 32 | int icls = fpclassify (__imag__ x); | |
| 33 | ||
| 34 | if (rcls == FP_ZERO && icls == FP_ZERO) | |
| 35 | { | |
| 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); | |
| 41 | } | |
| 42 | else if (rcls != FP_NAN && icls != FP_NAN) | |
| 43 | { | |
| 44 | /* Neither real nor imaginary part is NaN. */ | |
| 45 | __real__ result = __ieee754_log10 (__ieee754_hypot (__real__ x, | |
| 46 | __imag__ x)); | |
| bd355af0 | 47 | __imag__ result = M_LOG10E * __ieee754_atan2 (__imag__ x, __real__ x); |
| dfd2257a UD |
48 | } |
| 49 | else | |
| 50 | { | |
| 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 (""); | |
| 57 | } | |
| 58 | ||
| 59 | return result; | |
| 60 | } | |
| 61 | weak_alias (__clog10, clog10) | |
| 62 | #ifdef NO_LONG_DOUBLE | |
| 63 | strong_alias (__clog10, __clog10l) | |
| 64 | weak_alias (__clog10, clog10l) | |
| 65 | #endif |