s_ccoshf.c revision 331722 
1/*-
2 * Copyright (c) 2005 Bruce D. Evans and Steven G. Kargl
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 * Float version of ccosh().  See s_ccosh.c for details.
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: stable/11/lib/msun/src/s_ccoshf.c 331722 2018-03-29 02:50:57Z eadler $");
33
34#include <complex.h>
35#include <math.h>
36
37#include "math_private.h"
38
39static const float huge = 0x1p127;
40
41float complex
42ccoshf(float complex z)
43{
44	float x, y, h;
45	int32_t hx, hy, ix, iy;
46
47	x = crealf(z);
48	y = cimagf(z);
49
50	GET_FLOAT_WORD(hx, x);
51	GET_FLOAT_WORD(hy, y);
52
53	ix = 0x7fffffff & hx;
54	iy = 0x7fffffff & hy;
55
56	if (ix < 0x7f800000 && iy < 0x7f800000) {
57		if (iy == 0)
58			return (CMPLXF(coshf(x), x * y));
59		if (ix < 0x41100000)	/* |x| < 9: normal case */
60			return (CMPLXF(coshf(x) * cosf(y), sinhf(x) * sinf(y)));
61
62		/* |x| >= 9, so cosh(x) ~= exp(|x|) */
63		if (ix < 0x42b17218) {
64			/* x < 88.7: expf(|x|) won't overflow */
65			h = expf(fabsf(x)) * 0.5F;
66			return (CMPLXF(h * cosf(y), copysignf(h, x) * sinf(y)));
67		} else if (ix < 0x4340b1e7) {
68			/* x < 192.7: scale to avoid overflow */
69			z = __ldexp_cexpf(CMPLXF(fabsf(x), y), -1);
70			return (CMPLXF(crealf(z), cimagf(z) * copysignf(1, x)));
71		} else {
72			/* x >= 192.7: the result always overflows */
73			h = huge * x;
74			return (CMPLXF(h * h * cosf(y), h * sinf(y)));
75		}
76	}
77
78	if (ix == 0)			/* && iy >= 0x7f800000 */
79		return (CMPLXF(y - y, x * copysignf(0, y)));
80
81	if (iy == 0)			/* && ix >= 0x7f800000 */
82		return (CMPLXF(x * x, copysignf(0, x) * y));
83
84	if (ix < 0x7f800000)		/* && iy >= 0x7f800000 */
85		return (CMPLXF(y - y, x * (y - y)));
86
87	if (ix == 0x7f800000) {
88		if (iy >= 0x7f800000)
89			return (CMPLXF(INFINITY, x * (y - y)));
90		return (CMPLXF(INFINITY * cosf(y), x * sinf(y)));
91	}
92
93	return (CMPLXF((x * x) * (y - y), (x + x) * (y - y)));
94}
95
96float complex
97ccosf(float complex z)
98{
99
100	return (ccoshf(CMPLXF(-cimagf(z), crealf(z))));
101}
102