1 /* Complex tangent function for long double. IBM extended format version.
2 Copyright (C) 1997,2005,2006 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
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.
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.
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
24 #include <math_ldbl_opt.h>
26 #include "math_private.h"
29 __complex__
long double
30 __ctanl (__complex__
long double x
)
32 __complex__
long double res
;
34 if (!isfinite (__real__ x
) || !isfinite (__imag__ x
))
36 if (__isinfl (__imag__ x
))
38 __real__ res
= __copysignl (0.0, __real__ x
);
39 __imag__ res
= __copysignl (1.0, __imag__ x
);
41 else if (__real__ x
== 0.0)
47 __real__ res
= __nanl ("");
48 __imag__ res
= __nanl ("");
51 if (__isinfl (__real__ x
))
52 feraiseexcept (FE_INVALID
);
58 long double sin2rx
, cos2rx
;
61 __sincosl (2.0 * __real__ x
, &sin2rx
, &cos2rx
);
63 den
= cos2rx
+ __ieee754_coshl (2.0 * __imag__ x
);
68 __complex__
long double ez
= __cexpl (1.0i
* x
);
69 __complex__
long double emz
= __cexpl (-1.0i
* x
);
71 res
= (ez
- emz
) / (ez
+ emz
) * -1.0i
;
75 __real__ res
= sin2rx
/ den
;
76 __imag__ res
= __ieee754_sinhl (2.0 * __imag__ x
) / den
;
78 /* __gcc_qmul does not respect -0.0 so we need the following fixup. */
79 if ((__real__ res
== 0.0) && (__real__ x
== 0.0))
80 __real__ res
= __real__ x
;
82 if ((__real__ res
== 0.0) && (__imag__ x
== 0.0))
83 __imag__ res
= __imag__ x
;
88 long_double_symbol (libm
, __ctanl
, ctanl
);