1 /* $NetBSD: catanl.c,v 1.1 2014/10/10 00:48:18 christos Exp $ */
2
3 /*-
4 * Copyright (c) 2007 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software written by Stephen L. Moshier.
8 * It is redistributed by the NetBSD Foundation by permission of the author.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <complex.h>
33 #include <math.h>
34 #include "cephes_subrl.h"
35
36 #ifdef _HAVE_LONG_DOUBLE_MATH
37
38 #ifdef __weak_alias
__weak_alias(catanl,_catanl)39 __weak_alias(catanl, _catanl)
40 #endif
41
42 long double complex
43 catanl(long double complex z)
44 {
45 long double complex w;
46 long double a, t, x, x2, y;
47
48 x = creall(z);
49 y = cimagl(z);
50
51 if ((x == 0.0L) && (y > 1.0L))
52 goto ovrf;
53
54 x2 = x * x;
55 a = 1.0L - x2 - (y * y);
56 if (a == 0.0L)
57 goto ovrf;
58
59 t = 0.5L * atan2l(2.0L * x, a);
60 w = _redupil(t);
61
62 t = y - 1.0L;
63 a = x2 + (t * t);
64 if (a == 0.0L)
65 goto ovrf;
66
67 t = y + 1.0L;
68 a = (x2 + (t * t))/a;
69 w = w + (0.25L * logl(a)) * (long double complex) I;
70 return w;
71
72 ovrf:
73 #if 0
74 mtherr ("catanl", OVERFLOW);
75 #endif
76 w = HUGE_VALL + HUGE_VALL * (long double complex) I;
77 return w;
78 }
79
80 #endif
81
