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