xref: /illumos-gate/usr/src/lib/libm/common/complex/ccoshf.c (revision 22028508fd28d36ff74dc02c5774a8ba1f0db045)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
23  */
24 /*
25  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
26  * Use is subject to license terms.
27  */
28 
29 #pragma weak __ccoshf = ccoshf
30 
31 #include "libm.h"
32 #include "complex_wrapper.h"
33 
34 #if defined(__i386) && !defined(__amd64)
35 extern int __swapRP(int);
36 #endif
37 
38 static const float zero = 0.0F, half = 0.5F;
39 
40 fcomplex
41 ccoshf(fcomplex z) {
42 	float		t, x, y, S, C;
43 	double		w;
44 	int		hx, ix, hy, iy, n;
45 	fcomplex	ans;
46 
47 	x = F_RE(z);
48 	y = F_IM(z);
49 	hx = THE_WORD(x);
50 	ix = hx & 0x7fffffff;
51 	hy = THE_WORD(y);
52 	iy = hy & 0x7fffffff;
53 	x = fabsf(x);
54 	y = fabsf(y);
55 
56 	sincosf(y, &S, &C);
57 	if (ix >= 0x41600000) {	/* |x| > 14 = prec/2 (14,28,34,60) */
58 		if (ix >= 0x42B171AA) {	/* |x| > 88.722... ~ log(2**128) */
59 			if (ix >= 0x7f800000) {	/* |x| is inf or NaN */
60 				if (iy == 0) {
61 					F_RE(ans) = x;
62 					F_IM(ans) = y;
63 				} else if (iy >= 0x7f800000) {
64 					F_RE(ans) = x;
65 					F_IM(ans) = x - y;
66 				} else {
67 					F_RE(ans) = C * x;
68 					F_IM(ans) = S * x;
69 				}
70 			} else {
71 #if defined(__i386) && !defined(__amd64)
72 				int	rp = __swapRP(fp_extended);
73 #endif
74 				/* return (C, S) * exp(x) / 2 */
75 				w = __k_cexp((double)x, &n);
76 				F_RE(ans) = (float)scalbn(C * w, n - 1);
77 				F_IM(ans) = (float)scalbn(S * w, n - 1);
78 #if defined(__i386) && !defined(__amd64)
79 				if (rp != fp_extended)
80 					(void) __swapRP(rp);
81 #endif
82 			}
83 		} else {
84 			t = expf(x) * half;
85 			F_RE(ans) = C * t;
86 			F_IM(ans) = S * t;
87 		}
88 	} else {
89 		if (ix == 0) {	/* x = 0, return (C,0) */
90 			F_RE(ans) = C;
91 			F_IM(ans) = zero;
92 		} else {
93 			F_RE(ans) = C * coshf(x);
94 			F_IM(ans) = S * sinhf(x);
95 		}
96 	}
97 	if ((hx ^ hy) < 0)
98 		F_IM(ans) = -F_IM(ans);
99 	return (ans);
100 }
101