1 /* Complex hyperbole tangent for double. 2 Copyright (C) 1997 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. 5 6 The GNU C Library is free software; you can redistribute it and/or 7 modify it under the terms of the GNU Lesser General Public 8 License as published by the Free Software Foundation; either 9 version 2.1 of the License, or (at your option) any later version. 10 11 The GNU C Library is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 Lesser General Public License for more details. 15 16 You should have received a copy of the GNU Lesser General Public 17 License along with the GNU C Library; if not, write to the Free 18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 19 02111-1307 USA. */ 20 21 #include <complex.h> 22 #include <fenv.h> 23 #include <math.h> 24 25 #include "math_private.h" 26 27 28 __complex__ double 29 __ctanh (__complex__ double x) 30 { 31 __complex__ double res; 32 33 if (!isfinite (__real__ x) || !isfinite (__imag__ x)) 34 { 35 if (__isinf (__real__ x)) 36 { 37 __real__ res = copysign (1.0, __real__ x); 38 __imag__ res = copysign (0.0, __imag__ x); 39 } 40 else if (__imag__ x == 0.0) 41 { 42 res = x; 43 } 44 else 45 { 46 __real__ res = nan (""); 47 __imag__ res = nan (""); 48 49 #ifdef FE_INVALID 50 if (__isinf (__imag__ x)) 51 feraiseexcept (FE_INVALID); 52 #endif 53 } 54 } 55 else 56 { 57 double sin2ix, cos2ix; 58 double den; 59 60 sincos (2.0 * __imag__ x, &sin2ix, &cos2ix); 61 62 den = (cosh (2.0 * __real__ x) + cos2ix); 63 64 __real__ res = sinh (2.0 * __real__ x) / den; 65 __imag__ res = sin2ix / den; 66 } 67 68 return res; 69 } 70 weak_alias (__ctanh, ctanh) 71 #ifdef NO_LONG_DOUBLE 72 strong_alias (__ctanh, __ctanhl) 73 weak_alias (__ctanh, ctanhl) 74 #endif 75