xref: /freebsd/lib/msun/src/s_csinh.c (revision 3daee1d6c3783e32a226d145f85a887007f5754b)
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  * Hyperbolic sine of a complex argument z = x + i y.
29  *
30  * sinh(z) = sinh(x+iy)
31  *         = sinh(x) cos(y) + i cosh(x) sin(y).
32  *
33  * Exceptional values are noted in the comments within the source code.
34  * These values and the return value were taken from n1124.pdf.
35  */
36 
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include <complex.h>
41 #include <math.h>
42 
43 #include "math_private.h"
44 
45 double complex
46 csinh(double complex z)
47 {
48 	double x, y;
49 	int32_t hx, hy, ix, iy, lx, ly;
50 
51 	x = creal(z);
52 	y = cimag(z);
53 
54 	EXTRACT_WORDS(hx, lx, x);
55 	EXTRACT_WORDS(hy, ly, y);
56 
57 	ix = 0x7fffffff & hx;
58 	iy = 0x7fffffff & hy;
59 
60 	/* Handle the nearly-non-exceptional cases where x and y are finite. */
61 	if (ix < 0x7ff00000 && iy < 0x7ff00000) {
62 		if ((iy | ly) == 0)
63 			return (cpack(sinh(x), y));
64 		/* XXX We don't handle |x| > DBL_MAX ln(2) yet. */
65 		return (cpack(sinh(x) * cos(y), cosh(x) * sin(y)));
66 	}
67 
68 	/*
69 	 * sinh(+-0 +- I Inf) = sign(d(+-0, dNaN))0 + I dNaN.
70 	 * The sign of 0 in the result is unspecified.  Choice = normally
71 	 * the same as dNaN.  Raise the invalid floating-point exception.
72 	 *
73 	 * sinh(+-0 +- I NaN) = sign(d(+-0, NaN))0 + I d(NaN).
74 	 * The sign of 0 in the result is unspecified.  Choice = normally
75 	 * the same as d(NaN).
76 	 */
77 	if ((ix | lx) == 0 && iy >= 0x7ff00000)
78 		return (cpack(copysign(0, x * (y - y)), y - y));
79 
80 	/*
81 	 * sinh(+-Inf +- I 0) = +-Inf + I (+-)(+-)0.
82 	 *
83 	 * sinh(NaN +- I 0)   = d(NaN) + I +-0.
84 	 */
85 	if ((iy | ly) == 0 && ix >= 0x7ff00000) {
86 		if (((hx & 0xfffff) | lx) == 0)
87 			return (cpack(x, copysign(0, x) * y));
88 		return (cpack(x, copysign(0, y)));
89 	}
90 
91 	/*
92 	 * sinh(x +- I Inf) = dNaN + I dNaN.
93 	 * Raise the invalid floating-point exception for finite nonzero x.
94 	 *
95 	 * sinh(x + I NaN) = d(NaN) + I d(NaN).
96 	 * Optionally raises the invalid floating-point exception for finite
97 	 * nonzero x.  Choice = don't raise (except for signaling NaNs).
98 	 */
99 	if (ix < 0x7ff00000 && iy >= 0x7ff00000)
100 		return (cpack(y - y, x * (y - y)));
101 
102 	/*
103 	 * sinh(+-Inf + I NaN)  = +-Inf + I d(NaN).
104 	 * The sign of Inf in the result is unspecified.  Choice = normally
105 	 * the same as d(NaN).
106 	 *
107 	 * sinh(+-Inf +- I Inf) = +Inf + I dNaN.
108 	 * The sign of Inf in the result is unspecified.  Choice = always +.
109 	 * Raise the invalid floating-point exception.
110 	 *
111 	 * sinh(+-Inf + I y)   = +-Inf cos(y) + I Inf sin(y)
112 	 */
113 	if (ix >= 0x7ff00000 && ((hx & 0xfffff) | lx) == 0) {
114 		if (iy >= 0x7ff00000)
115 			return (cpack(x * x, x * (y - y)));
116 		return (cpack(x * cos(y), INFINITY * sin(y)));
117 	}
118 
119 	/*
120 	 * sinh(NaN + I NaN)  = d(NaN) + I d(NaN).
121 	 *
122 	 * sinh(NaN +- I Inf) = d(NaN) + I d(NaN).
123 	 * Optionally raises the invalid floating-point exception.
124 	 * Choice = raise.
125 	 *
126 	 * sinh(NaN + I y)    = d(NaN) + I d(NaN).
127 	 * Optionally raises the invalid floating-point exception for finite
128 	 * nonzero y.  Choice = don't raise (except for signaling NaNs).
129 	 */
130 	return (cpack((x * x) * (y - y), (x + x) * (y - y)));
131 }
132 
133 double complex
134 csin(double complex z)
135 {
136 
137 	/* csin(z) = -I * csinh(I * z) */
138 	z = csinh(cpack(-cimag(z), creal(z)));
139 	return (cpack(cimag(z), -creal(z)));
140 }
141