s_ccoshf.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2005 Bruce D. Evans and Steven G. Kargl
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 * Float version of ccosh().  See s_ccosh.c for details.
31 */
32
33#include <sys/cdefs.h>
34__FBSDID("$FreeBSD: stable/11/lib/msun/src/s_ccoshf.c 330897 2018-03-14 03:19:51Z eadler $");
35
36#include <complex.h>
37#include <math.h>
38
39#include "math_private.h"
40
41static const float huge = 0x1p127;
42
43float complex
44ccoshf(float complex z)
45{
46	float x, y, h;
47	int32_t hx, hy, ix, iy;
48
49	x = crealf(z);
50	y = cimagf(z);
51
52	GET_FLOAT_WORD(hx, x);
53	GET_FLOAT_WORD(hy, y);
54
55	ix = 0x7fffffff & hx;
56	iy = 0x7fffffff & hy;
57
58	if (ix < 0x7f800000 && iy < 0x7f800000) {
59		if (iy == 0)
60			return (CMPLXF(coshf(x), x * y));
61		if (ix < 0x41100000)	/* |x| < 9: normal case */
62			return (CMPLXF(coshf(x) * cosf(y), sinhf(x) * sinf(y)));
63
64		/* |x| >= 9, so cosh(x) ~= exp(|x|) */
65		if (ix < 0x42b17218) {
66			/* x < 88.7: expf(|x|) won't overflow */
67			h = expf(fabsf(x)) * 0.5F;
68			return (CMPLXF(h * cosf(y), copysignf(h, x) * sinf(y)));
69		} else if (ix < 0x4340b1e7) {
70			/* x < 192.7: scale to avoid overflow */
71			z = __ldexp_cexpf(CMPLXF(fabsf(x), y), -1);
72			return (CMPLXF(crealf(z), cimagf(z) * copysignf(1, x)));
73		} else {
74			/* x >= 192.7: the result always overflows */
75			h = huge * x;
76			return (CMPLXF(h * h * cosf(y), h * sinf(y)));
77		}
78	}
79
80	if (ix == 0)			/* && iy >= 0x7f800000 */
81		return (CMPLXF(y - y, x * copysignf(0, y)));
82
83	if (iy == 0)			/* && ix >= 0x7f800000 */
84		return (CMPLXF(x * x, copysignf(0, x) * y));
85
86	if (ix < 0x7f800000)		/* && iy >= 0x7f800000 */
87		return (CMPLXF(y - y, x * (y - y)));
88
89	if (ix == 0x7f800000) {
90		if (iy >= 0x7f800000)
91			return (CMPLXF(INFINITY, x * (y - y)));
92		return (CMPLXF(INFINITY * cosf(y), x * sinf(y)));
93	}
94
95	return (CMPLXF((x * x) * (y - y), (x + x) * (y - y)));
96}
97
98float complex
99ccosf(float complex z)
100{
101
102	return (ccoshf(CMPLXF(-cimagf(z), crealf(z))));
103}
104