diff options
Diffstat (limited to 'math/s_clogl.c')
| -rw-r--r-- | math/s_clogl.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/math/s_clogl.c b/math/s_clogl.c new file mode 100644 index 0000000000..43118f768c --- /dev/null +++ b/math/s_clogl.c @@ -0,0 +1,61 @@ +/* Compute complex natural logarithm. + Copyright (C) 1997, 1998 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__ long double +__clogl (__complex__ long double x) +{ + __complex__ long 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_PIl : 0.0; + __imag__ result = __copysignl (__imag__ result, __imag__ x); + /* Yes, the following line raises an exception. */ + __real__ result = -1.0 / fabsl (__real__ x); + } + else if (rcls != FP_NAN && icls != FP_NAN) + { + /* Neither real nor imaginary part is NaN. */ + __real__ result = __ieee754_logl (__ieee754_hypotl (__real__ x, + __imag__ x)); + __imag__ result = __ieee754_atan2l (__imag__ x, __real__ x); + } + else + { + __imag__ result = __nanl (""); + if (rcls == FP_INFINITE || icls == FP_INFINITE) + /* Real or imaginary part is infinite. */ + __real__ result = HUGE_VALL; + else + __real__ result = __nanl (""); + } + + return result; +} +weak_alias (__clogl, clogl) |