1 /* $NetBSD: ctanl.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 "../src/namespace.h"
33 #include <complex.h>
34 #include <math.h>
35 #include <float.h>
36 #include "cephes_subrl.h"
37 
38 #define MAXNUM LDBL_MAX
39 
40 long double complex
ctanl(long double complex z)41 ctanl(long double complex z)
42 {
43 	long double complex w;
44 	long double d;
45 
46 	d = cosl(2.0L * creall(z)) + coshl(2.0L * cimagl(z));
47 
48 	if (fabsl(d) < 0.25L)
49 		d = _ctansl(z);
50 
51 	if (d == 0.0L) {
52 		/* mtherr ("ctan", OVERFLOW); */
53 		w = MAXNUM + MAXNUM * I;
54 		return w;
55 	}
56 
57 	w = sinl(2.0L * creall(z)) / d + (sinhl(2.0L * cimagl(z)) / d) * I;
58 	return w;
59 }
60