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: head/lib/msun/src/s_ctanhf.c 284428 2015-06-15 20:47:26Z tijl $");
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 (CMPLXF((x + 0) * (y + 0),
55 y == 0 ? y : (x + 0) * (y + 0)));
56 SET_FLOAT_WORD(x, hx - 0x40000000);
57 return (CMPLXF(x,
58 copysignf(0, isinf(y) ? y : sinf(y) * cosf(y))));
59 }
60
61 if (!isfinite(y))
62 return (CMPLXF(y - y, y - y));
63
64 if (ix >= 0x41300000) { /* |x| >= 11 */
65 float exp_mx = expf(-fabsf(x));
66 return (CMPLXF(copysignf(1, x),
67 4 * sinf(y) * cosf(y) * exp_mx * exp_mx));
68 }
69
70 t = tanf(y);
71 beta = 1.0 + t * t;
72 s = sinhf(x);
73 rho = sqrtf(1 + s * s);
74 denom = 1 + beta * s * s;
75 return (CMPLXF((beta * rho * s) / denom, t / denom));
76 }
77
78 float complex
ctanf(float complex z)79 ctanf(float complex z)
80 {
81
82 z = ctanhf(CMPLXF(cimagf(z), crealf(z)));
83 return (CMPLXF(cimagf(z), crealf(z)));
84 }
85
86