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Diffstat (limited to 'math/s_catanf.c')
| -rw-r--r-- | math/s_catanf.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/math/s_catanf.c b/math/s_catanf.c new file mode 100644 index 0000000000..25eec2b1b5 --- /dev/null +++ b/math/s_catanf.c @@ -0,0 +1,87 @@ +/* Return arc tangent of complex float value. + 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__ float +__catanf (__complex__ float x) +{ + __complex__ float res; + int rcls = fpclassify (__real__ x); + int icls = fpclassify (__imag__ x); + + if (rcls <= FP_INFINITE || icls <= FP_INFINITE) + { + if (rcls == FP_INFINITE) + { + __real__ res = __copysignf (M_PI_2, __real__ x); + __imag__ res = __copysignf (0.0, __imag__ x); + } + else if (icls == FP_INFINITE) + { + if (rcls >= FP_ZERO) + __real__ res = __copysignf (M_PI_2, __real__ x); + else + __real__ res = __nanf (""); + __imag__ res = __copysignf (0.0, __imag__ x); + } + else if (icls == FP_ZERO || icls == FP_INFINITE) + { + __real__ res = __nanf (""); + __imag__ res = __copysignf (0.0, __imag__ x); + } + else + { + __real__ res = __nanf (""); + __imag__ res = __nanf (""); + } + } + else if (rcls == FP_ZERO && icls == FP_ZERO) + { + res = x; + } + else + { + float r2, num, den; + + r2 = __real__ x * __real__ x; + + den = 1 - r2 - __imag__ x * __imag__ x; + + __real__ res = 0.5 * __ieee754_atan2f (2.0 * __real__ x, den); + + num = __imag__ x + 1.0; + num = r2 + num * num; + + den = __imag__ x - 1.0; + den = r2 + den * den; + + __imag__ res = 0.25 * __ieee754_logf (num / den); + } + + return res; +} +#ifndef __catanf +weak_alias (__catanf, catanf) +#endif |