xref: /titanic_41/usr/src/lib/libc/port/gen/lmath.c (revision 7257d1b4d25bfac0c802847390e98a464fd787ac)
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 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	  All Rights Reserved	*/
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 /*
33  * This set of routines used to be implemented mostly in assembler.
34  *
35  * Since the purpose they have is now rather vestigial, and 64-bit
36  * machines can do operations on 64-bit quantities pretty efficiently,
37  * a C implementation seems quite adequate and much more maintainable.
38  */
39 
40 #include "lint.h"
41 #include <sys/types.h>
42 #include <sys/dl.h>
43 
44 typedef union {
45 	long	xword;
46 	dl_t	dl;
47 } dlx_t;
48 
49 dl_t
ladd(dl_t lop,dl_t rop)50 ladd(dl_t lop, dl_t rop)
51 {
52 	dlx_t r;
53 	/* LINTED pointer cast may result in improper alignment */
54 	r.xword = *(long *)&lop + *(long *)&rop;
55 	return (r.dl);
56 }
57 
58 dl_t
lshiftl(dl_t op,int cnt)59 lshiftl(dl_t op, int cnt)
60 {
61 	dlx_t r;
62 	if (cnt < 0)
63 		/* LINTED pointer cast may result in improper alignment */
64 		r.xword = (long)(*(ulong_t *)&op >> (-cnt));
65 	else
66 		/* LINTED pointer cast may result in improper alignment */
67 		r.xword = *(long *)&op << cnt;
68 	return (r.dl);
69 }
70 
71 int
lsign(dl_t op)72 lsign(dl_t op)
73 {
74 	/* LINTED pointer cast may result in improper alignment */
75 	return ((*(long *)&op) >> 63);
76 }
77 
78 dl_t
lsub(dl_t lop,dl_t rop)79 lsub(dl_t lop, dl_t rop)
80 {
81 	dlx_t r;
82 	/* LINTED pointer cast may result in improper alignment */
83 	r.xword = *(long *)&lop - *(long *)&rop;
84 	return (r.dl);
85 }
86 
87 dl_t
lmul(dl_t lop,dl_t rop)88 lmul(dl_t lop, dl_t rop)
89 {
90 	dlx_t r;
91 	/* LINTED pointer cast may result in improper alignment */
92 	r.xword = *(long *)&lop * *(long *)&rop;
93 	return (r.dl);
94 }
95