xref: /illumos-gate/usr/src/lib/libm/common/complex/cproj.c (revision 4c28a617e3922d92a58e813a5b955eb526b9c386)
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 __cproj = cproj
31 
32 /* INDENT OFF */
33 /*
34  * dcomplex cproj(dcomplex z);
35  *
36  * If one of the component of z = (x,y) is an inf, then
37  *	cproj(z) = (+inf, copysign(0,y));
38  * otherwise,
39  *	cproj(z) = z
40  */
41 /* INDENT ON */
42 
43 #include "libm.h"			/* fabs */
44 #include "complex_wrapper.h"
45 
46 static const double zero = 0.0;
47 
48 dcomplex
49 cproj(dcomplex z) {
50 	double x, y;
51 	int ix, iy, hx, hy, lx, ly;
52 
53 	x = D_RE(z);
54 	y = D_IM(z);
55 	hx = HI_WORD(x);
56 	lx = LO_WORD(x);
57 	hy = HI_WORD(y);
58 	ly = LO_WORD(y);
59 	ix = hx & 0x7fffffff;
60 	iy = hy & 0x7fffffff;
61 	if (ISINF(iy, ly)) {
62 		D_RE(z) = fabs(y);
63 		D_IM(z) = hy >= 0 ? zero : -zero;
64 	} else if (ISINF(ix, lx)) {
65 		D_RE(z) = fabs(x);
66 		D_IM(z) = hy >= 0 ? zero : -zero;
67 	}
68 	return (z);
69 }
70