1 /* Return arc hyperbole tangent for float value.
2 Copyright (C) 1997-2013 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, see
18 <http://www.gnu.org/licenses/>. */
22 #include <math_private.h>
26 __catanhf (__complex__ float x)
28 __complex__ float res;
29 int rcls = fpclassify (__real__ x);
30 int icls = fpclassify (__imag__ x);
32 if (__builtin_expect (rcls <= FP_INFINITE || icls <= FP_INFINITE, 0))
34 if (icls == FP_INFINITE)
36 __real__ res = __copysignf (0.0, __real__ x);
37 __imag__ res = __copysignf (M_PI_2, __imag__ x);
39 else if (rcls == FP_INFINITE || rcls == FP_ZERO)
41 __real__ res = __copysignf (0.0, __real__ x);
43 __imag__ res = __copysignf (M_PI_2, __imag__ x);
45 __imag__ res = __nanf ("");
49 __real__ res = __nanf ("");
50 __imag__ res = __nanf ("");
53 else if (__builtin_expect (rcls == FP_ZERO && icls == FP_ZERO, 0))
59 float i2 = __imag__ x * __imag__ x;
61 float num = 1.0f + __real__ x;
64 float den = 1.0f - __real__ x;
69 __real__ res = 0.25f * __ieee754_logf (f);
72 num = 4.0f * __real__ x;
73 __real__ res = 0.25f * __log1pf (num / den);
76 den = 1 - __real__ x * __real__ x - i2;
78 __imag__ res = 0.5f * __ieee754_atan2f (2.0f * __imag__ x, den);
84 weak_alias (__catanhf, catanhf)