1 /* origin: FreeBSD /usr/src/lib/msun/src/s_ctanhf.c */
3 * Copyright (c) 2011 David Schultz
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice unmodified, this list of conditions, and the following
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 * Hyperbolic tangent of a complex argument z. See s_ctanh.c for details.
33 float complex ctanhf(float complex z)
36 float t, beta, s, rho, denom;
42 GET_FLOAT_WORD(hx, x);
45 if (ix >= 0x7f800000) {
47 return cpackf(x, (y == 0 ? y : x * y));
48 SET_FLOAT_WORD(x, hx - 0x40000000);
49 return cpackf(x, copysignf(0, isinf(y) ? y : sinf(y) * cosf(y)));
53 return cpackf(y - y, y - y);
55 if (ix >= 0x41300000) { /* x >= 11 */
56 float exp_mx = expf(-fabsf(x));
57 return cpackf(copysignf(1, x), 4 * sinf(y) * cosf(y) * exp_mx * exp_mx);
63 rho = sqrtf(1 + s * s);
64 denom = 1 + beta * s * s;
65 return cpackf((beta * rho * s) / denom, t / denom);