1/* origin: FreeBSD /usr/src/lib/msun/src/s_csinhf.c */
2/*-
3 * Copyright (c) 2005 Bruce D. Evans and Steven G. Kargl
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice unmodified, this list of conditions, and the following
11 *    disclaimer.
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.
15 *
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
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27/*
28 * Hyperbolic sine of a complex argument z.  See s_csinh.c for details.
29 */
30
31#include "libm.h"
32
33static const float huge = 0x1p127;
34
35float complex csinhf(float complex z)
36{
37	float x, y, h;
38	int32_t hx, hy, ix, iy;
39
40	x = crealf(z);
41	y = cimagf(z);
42
43	GET_FLOAT_WORD(hx, x);
44	GET_FLOAT_WORD(hy, y);
45
46	ix = 0x7fffffff & hx;
47	iy = 0x7fffffff & hy;
48
49	if (ix < 0x7f800000 && iy < 0x7f800000) {
50		if (iy == 0)
51			return CMPLXF(sinhf(x), y);
52		if (ix < 0x41100000)    /* small x: normal case */
53			return CMPLXF(sinhf(x) * cosf(y), coshf(x) * sinf(y));
54
55		/* |x| >= 9, so cosh(x) ~= exp(|x|) */
56		if (ix < 0x42b17218) {
57			/* x < 88.7: expf(|x|) won't overflow */
58			h = expf(fabsf(x)) * 0.5f;
59			return CMPLXF(copysignf(h, x) * cosf(y), h * sinf(y));
60		} else if (ix < 0x4340b1e7) {
61			/* x < 192.7: scale to avoid overflow */
62			z = __ldexp_cexpf(CMPLXF(fabsf(x), y), -1);
63			return CMPLXF(crealf(z) * copysignf(1, x), cimagf(z));
64		} else {
65			/* x >= 192.7: the result always overflows */
66			h = huge * x;
67			return CMPLXF(h * cosf(y), h * h * sinf(y));
68		}
69	}
70
71	if (ix == 0 && iy >= 0x7f800000)
72		return CMPLXF(copysignf(0, x * (y - y)), y - y);
73
74	if (iy == 0 && ix >= 0x7f800000) {
75		if ((hx & 0x7fffff) == 0)
76			return CMPLXF(x, y);
77		return CMPLXF(x, copysignf(0, y));
78	}
79
80	if (ix < 0x7f800000 && iy >= 0x7f800000)
81		return CMPLXF(y - y, x * (y - y));
82
83	if (ix >= 0x7f800000 && (hx & 0x7fffff) == 0) {
84		if (iy >= 0x7f800000)
85			return CMPLXF(x * x, x * (y - y));
86		return CMPLXF(x * cosf(y), INFINITY * sinf(y));
87	}
88
89	return CMPLXF((x * x) * (y - y), (x + x) * (y - y));
90}
91