xref: /titanic_41/usr/src/lib/libc/port/gen/lmath.c (revision fa9e4066f08beec538e775443c5be79dd423fcab)
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 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*	Copyright (c) 1988 AT&T	*/
30 /*	  All Rights Reserved	*/
31 
32 
33 /*
34  * This set of routines used to be implemented mostly in assembler.
35  *
36  * Since the purpose they have is now rather vestigial, and 64-bit
37  * machines can do operations on 64-bit quantities pretty efficiently,
38  * a C implementation seems quite adequate and much more maintainable.
39  */
40 
41 #pragma weak ladd = _ladd
42 #pragma weak lsub = _lsub
43 #pragma weak lshiftl = _lshiftl
44 #pragma weak lsign = _lsign
45 #pragma weak lmul = _lmul
46 
47 #include "synonyms.h"
48 #include <sys/types.h>
49 #include <sys/dl.h>
50 
51 typedef union {
52 	long	xword;
53 	dl_t	dl;
54 } dlx_t;
55 
56 dl_t
57 ladd(dl_t lop, dl_t rop)
58 {
59 	dlx_t r;
60 	/* LINTED pointer cast may result in improper alignment */
61 	r.xword = *(long *)&lop + *(long *)&rop;
62 	return (r.dl);
63 }
64 
65 dl_t
66 lshiftl(dl_t op, int cnt)
67 {
68 	dlx_t r;
69 	if (cnt < 0)
70 		/* LINTED pointer cast may result in improper alignment */
71 		r.xword = (long)(*(ulong_t *)&op >> (-cnt));
72 	else
73 		/* LINTED pointer cast may result in improper alignment */
74 		r.xword = *(long *)&op << cnt;
75 	return (r.dl);
76 }
77 
78 int
79 lsign(dl_t op)
80 {
81 	/* LINTED pointer cast may result in improper alignment */
82 	return ((*(long *)&op) >> 63);
83 }
84 
85 dl_t
86 lsub(dl_t lop, dl_t rop)
87 {
88 	dlx_t r;
89 	/* LINTED pointer cast may result in improper alignment */
90 	r.xword = *(long *)&lop - *(long *)&rop;
91 	return (r.dl);
92 }
93 
94 dl_t
95 lmul(dl_t lop, dl_t rop)
96 {
97 	dlx_t r;
98 	/* LINTED pointer cast may result in improper alignment */
99 	r.xword = *(long *)&lop * *(long *)&rop;
100 	return (r.dl);
101 }
102