/* Return arc hyperbole tangent for 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 Library General Public License as published by the Free Software Foundation; either version 2 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 Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with the GNU C Library; see the file COPYING.LIB. 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 __catanhf (__complex__ float x) { __complex__ float res; int rcls = fpclassify (__real__ x); int icls = fpclassify (__imag__ x); if (rcls <= FP_INFINITE || icls <= FP_INFINITE) { if (icls == FP_INFINITE) { __real__ res = __copysignf (0.0, __real__ x); __imag__ res = __copysignf (M_PI_2, __imag__ x); } else if (rcls == FP_INFINITE || rcls == FP_ZERO) { __real__ res = __copysignf (0.0, __real__ x); if (icls >= FP_ZERO) __imag__ res = __copysignf (M_PI_2, __imag__ x); else __imag__ res = __nanf (""); } else { __real__ res = __nanf (""); __imag__ res = __nanf (""); } } else if (rcls == FP_ZERO && icls == FP_ZERO) { res = x; } else { float 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_logf (num) - __ieee754_logf (den)); den = 1 - __real__ x * __real__ x - i2; __imag__ res = 0.5 * __ieee754_atan2f (2.0 * __imag__ x, den); } return res; } weak_alias (__catanhf, catanhf)