1 /*-
2 * Copyright (c) 2011 David Schultz
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice unmodified, this list of conditions, and the following
10 * disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 /*
28 * Hyperbolic tangent of a complex argument z. See s_ctanh.c for details.
29 */
30
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33
34 #include <complex.h>
35 #include <math.h>
36
37 #include "math_private.h"
38
39 float complex
ctanhf(float complex z)40 ctanhf(float complex z)
41 {
42 float x, y;
43 float t, beta, s, rho, denom;
44 uint32_t hx, ix;
45
46 x = crealf(z);
47 y = cimagf(z);
48
49 GET_FLOAT_WORD(hx, x);
50 ix = hx & 0x7fffffff;
51
52 if (ix >= 0x7f800000) {
53 if (ix & 0x7fffff)
54 return (cpackf(x, (y == 0 ? y : x * y)));
55 SET_FLOAT_WORD(x, hx - 0x40000000);
56 return (cpackf(x,
57 copysignf(0, isinf(y) ? y : sinf(y) * cosf(y))));
58 }
59
60 if (!isfinite(y))
61 return (cpackf(y - y, y - y));
62
63 if (ix >= 0x41300000) { /* x >= 11 */
64 float exp_mx = expf(-fabsf(x));
65 return (cpackf(copysignf(1, x),
66 4 * sinf(y) * cosf(y) * exp_mx * exp_mx));
67 }
68
69 t = tanf(y);
70 beta = 1.0 + t * t;
71 s = sinhf(x);
72 rho = sqrtf(1 + s * s);
73 denom = 1 + beta * s * s;
74 return (cpackf((beta * rho * s) / denom, t / denom));
75 }
76
77 float complex
ctanf(float complex z)78 ctanf(float complex z)
79 {
80
81 z = ctanhf(cpackf(-cimagf(z), crealf(z)));
82 return (cpackf(cimagf(z), -crealf(z)));
83 }
84
85