xref: /illumos-gate/usr/src/lib/libc/i386/fp/_D_cplx_lr_div.c (revision 915894ef19890baaed00080f85f6b69e225cda98)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*
28  * _D_cplx_lr_div(z, w) returns z / w computed by the textbook
29  * formula without regard to exceptions or special cases.
30  *
31  * This code is intended to be used only when CX_LIMITED_RANGE is
32  * ON; otherwise use _D_cplx_div.
33  */
34 
35 #if !defined(i386) && !defined(__i386) && !defined(__amd64)
36 #error This code is for x86 only
37 #endif
38 
39 double _Complex
40 _D_cplx_lr_div(double _Complex z, double _Complex w)
41 {
42 	double _Complex	v = 0;
43 	long double	a, b, c, d, r;
44 
45 	/* LINTED alignment */
46 	a = ((double *)&z)[0];
47 	/* LINTED alignment */
48 	b = ((double *)&z)[1];
49 	/* LINTED alignment */
50 	c = ((double *)&w)[0];
51 	/* LINTED alignment */
52 	d = ((double *)&w)[1];
53 	r = 1.0f / (c * c + d * d);
54 	/* LINTED alignment */
55 	((double *)&v)[0] = (double)((a * c + b * d) * r);
56 	/* LINTED alignment */
57 	((double *)&v)[1] = (double)((b * c - a * d) * r);
58 	return (v);
59 }
60