diff options
Diffstat (limited to 'math/s_catanhl.c')
| -rw-r--r-- | math/s_catanhl.c | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/math/s_catanhl.c b/math/s_catanhl.c new file mode 100644 index 0000000000..c3fb0ce5ff --- /dev/null +++ b/math/s_catanhl.c @@ -0,0 +1,80 @@ +/* Return arc hyperbole tangent for long double value. + 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 +__catanhl (__complex__ long double x) +{ + __complex__ long double res; + int rcls = fpclassify (__real__ x); + int icls = fpclassify (__imag__ x); + + if (rcls <= FP_INFINITE || icls <= FP_INFINITE) + { + if (icls == FP_INFINITE) + { + __real__ res = __copysignl (0.0, __real__ x); + __imag__ res = __copysignl (M_PI_2l, __imag__ x); + } + else if (rcls == FP_INFINITE || rcls == FP_ZERO) + { + __real__ res = __copysignl (0.0, __real__ x); + if (icls >= FP_ZERO) + __imag__ res = __copysignl (M_PI_2l, __imag__ x); + else + __imag__ res = __nanl (""); + } + else + { + __real__ res = __nanl (""); + __imag__ res = __nanl (""); + } + } + else if (rcls == FP_ZERO && icls == FP_ZERO) + { + res = x; + } + else + { + long double i2, num, den; + + i2 = __imag__ x * __imag__ x; + + num = 1.0 + __real__ x; + num = i2 + num * num; + + den = 1.0 - __real__ x; + den = i2 + den * den; + + __real__ res = 0.25 * (__ieee754_logl (num) - __ieee754_logl (den)); + + den = 1 - __real__ x * __real__ x - i2; + + __imag__ res = 0.5 * __ieee754_atan2l (2.0 * __imag__ x, den); + } + + return res; +} +weak_alias (__catanhl, catanhl) |