xref: /haiku/src/system/libroot/posix/glibc/arch/generic/s_ctanhf.c (revision 7749d0bb0c358a3279b1b9cc76d8376e900130a5)
1 /* Complex hyperbole tangent for float.
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__ float
29 __ctanhf (__complex__ float x)
30 {
31   __complex__ float res;
32 
33   if (!isfinite (__real__ x) || !isfinite (__imag__ x))
34     {
35       if (__isinff (__real__ x))
36 	{
37 	  __real__ res = __copysignf (1.0, __real__ x);
38 	  __imag__ res = __copysignf (0.0, __imag__ x);
39 	}
40       else if (__imag__ x == 0.0)
41 	{
42 	  res = x;
43 	}
44       else
45 	{
46 	  __real__ res = __nanf ("");
47 	  __imag__ res = __nanf ("");
48 
49 #ifdef FE_INVALID
50 	  if (__isinff (__imag__ x))
51 	    feraiseexcept (FE_INVALID);
52 #endif
53 	}
54     }
55   else
56     {
57       float sin2ix, cos2ix;
58       float den;
59 
60       __sincosf (2.0 * __imag__ x, &sin2ix, &cos2ix);
61 
62       den = (__ieee754_coshf (2.0 * __real__ x) + cos2ix);
63 
64       __real__ res = __ieee754_sinhf (2.0 * __real__ x) / den;
65       __imag__ res = sin2ix / den;
66     }
67 
68   return res;
69 }
70 #ifndef __ctanhf
71 weak_alias (__ctanhf, ctanhf)
72 #endif
73