| /* Complex tangent function for long double. |
| Copyright (C) 1997, 2005 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 <fenv.h> |
| #include <math.h> |
| |
| #include "math_private.h" |
| |
| |
| __complex__ long double |
| __ctanl (__complex__ long double x) |
| { |
| __complex__ long double res; |
| |
| if (!isfinite (__real__ x) || !isfinite (__imag__ x)) |
| { |
| if (__isinfl (__imag__ x)) |
| { |
| __real__ res = __copysignl (0.0, __real__ x); |
| __imag__ res = __copysignl (1.0, __imag__ x); |
| } |
| else if (__real__ x == 0.0) |
| { |
| res = x; |
| } |
| else |
| { |
| __real__ res = __nanl (""); |
| __imag__ res = __nanl (""); |
| |
| #ifdef FE_INVALID |
| if (__isinfl (__real__ x)) |
| feraiseexcept (FE_INVALID); |
| #endif |
| } |
| } |
| else |
| { |
| long double sin2rx, cos2rx; |
| long double den; |
| |
| __sincosl (2.0 * __real__ x, &sin2rx, &cos2rx); |
| |
| den = cos2rx + __ieee754_coshl (2.0 * __imag__ x); |
| |
| |
| if (den == 0.0) |
| { |
| __complex__ long double ez = __cexpl (1.0i * x); |
| __complex__ long double emz = __cexpl (-1.0i * x); |
| |
| res = (ez - emz) / (ez + emz) * -1.0i; |
| } |
| else |
| { |
| __real__ res = sin2rx / den; |
| __imag__ res = __ieee754_sinhl (2.0 * __imag__ x) / den; |
| } |
| } |
| |
| return res; |
| } |
| weak_alias (__ctanl, ctanl) |