xref: /illumos-gate/usr/src/lib/libm/common/complex/cexpl.c (revision 08855964b9970604433f7b19dcd71cf5af5e5f14)
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 /*
23  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
24  */
25 /*
26  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  */
29 
30 #pragma weak __cexpl = cexpl
31 
32 #include "libm.h"		/* expl/isinfl/iszerol/scalbnl/sincosl */
33 #include "complex_wrapper.h"
34 
35 extern int isinfl(long double);
36 extern int iszerol(long double);
37 
38 /* INDENT OFF */
39 static const long double zero = 0.0L;
40 /* INDENT ON */
41 
42 ldcomplex
43 cexpl(ldcomplex z) {
44 	ldcomplex ans;
45 	long double x, y, t, c, s;
46 	int n, ix, iy, hx, hy;
47 
48 	x = LD_RE(z);
49 	y = LD_IM(z);
50 	hx = HI_XWORD(x);
51 	hy = HI_XWORD(y);
52 	ix = hx & 0x7fffffff;
53 	iy = hy & 0x7fffffff;
54 	if (iszerol(y)) {	/* y = 0 */
55 		LD_RE(ans) = expl(x);
56 		LD_IM(ans) = y;
57 	} else if (isinfl(x)) {	/* x is +-inf */
58 		if (hx < 0) {
59 			if (iy >= 0x7fff0000) {
60 				LD_RE(ans) = zero;
61 				LD_IM(ans) = zero;
62 			} else {
63 				sincosl(y, &s, &c);
64 				LD_RE(ans) = zero * c;
65 				LD_IM(ans) = zero * s;
66 			}
67 		} else {
68 			if (iy >= 0x7fff0000) {
69 				LD_RE(ans) = x;
70 				LD_IM(ans) = y - y;
71 			} else {
72 				(void) sincosl(y, &s, &c);
73 				LD_RE(ans) = x * c;
74 				LD_IM(ans) = x * s;
75 			}
76 		}
77 	} else {
78 		(void) sincosl(y, &s, &c);
79 		if (ix >= 0x400C62E4) {	/* |x| > 11356.52... ~ log(2**16384) */
80 			t = __k_cexpl(x, &n);
81 			LD_RE(ans) = scalbnl(t * c, n);
82 			LD_IM(ans) = scalbnl(t * s, n);
83 		} else {
84 			t = expl(x);
85 			LD_RE(ans) = t * c;
86 			LD_IM(ans) = t * s;
87 		}
88 	}
89 	return (ans);
90 }
91