xref: /freebsd/lib/msun/src/s_csinhf.c (revision 8df8b2d3e51d1b816201d8a1fe8bc29fe192e562)
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 csinh().  See s_csinh.c for details.
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include <complex.h>
37 #include <math.h>
38 
39 #include "math_private.h"
40 
41 static const float huge = 0x1p127;
42 
43 float complex
44 csinhf(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(sinhf(x), y));
61 		if (ix < 0x41100000)	/* |x| < 9: normal case */
62 			return (CMPLXF(sinhf(x) * cosf(y), coshf(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(copysignf(h, x) * cosf(y), h * 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) * copysignf(1, x), cimagf(z)));
73 		} else {
74 			/* x >= 192.7: the result always overflows */
75 			h = huge * x;
76 			return (CMPLXF(h * cosf(y), h * h * sinf(y)));
77 		}
78 	}
79 
80 	if (ix == 0)			/* && iy >= 0x7f800000 */
81 		return (CMPLXF(x, y - y));
82 
83 	if (iy == 0)			/* && ix >= 0x7f800000 */
84 		return (CMPLXF(x + x, y));
85 
86 	if (ix < 0x7f800000)		/* && iy >= 0x7f800000 */
87 		return (CMPLXF(y - y, y - y));
88 
89 	if (ix == 0x7f800000) {
90 		if (iy >= 0x7f800000)
91 			return (CMPLXF(x, y - y));
92 		return (CMPLXF(x * cosf(y), INFINITY * sinf(y)));
93 	}
94 
95 	return (CMPLXF(((long double)x + x) * (y - y),
96 	    ((long double)x * x) * (y - y)));
97 }
98 
99 float complex
100 csinf(float complex z)
101 {
102 
103 	z = csinhf(CMPLXF(cimagf(z), crealf(z)));
104 	return (CMPLXF(cimagf(z), crealf(z)));
105 }
106