xref: /titanic_50/usr/src/lib/libc/i386/gen/lshiftl.s (revision da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0)
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	.ident	"%Z%%M%	%I%	%E% SMI"
28
29	.file	"%M%"
30
31/ Shift a double long value.
32
33#include <sys/asm_linkage.h>
34
35	ANSI_PRAGMA_WEAK(lshiftl,function)
36
37#include "SYS.h"
38
39	.set	arg,8
40	.set	cnt,16
41	.set	ans,0
42
43	ENTRY(lshiftl)
44	popl	%eax
45	xchgl	%eax,0(%esp)
46
47	pushl	%eax
48	movl	arg(%esp),%eax
49	movl	arg+4(%esp),%edx
50	movl	cnt(%esp),%ecx
51	orl	%ecx,%ecx
52	jz	.lshiftld
53	jns	.lshiftlp
54
55/ We are doing a negative (right) shift
56
57	negl	%ecx
58
59.lshiftln:
60	sarl	$1,%edx
61	rcrl	$1,%eax
62	loop	.lshiftln
63	jmp	.lshiftld
64
65/ We are doing a positive (left) shift
66
67.lshiftlp:
68	shll	$1,%eax
69	rcll	$1,%edx
70	loop	.lshiftlp
71
72/ We are done.
73
74.lshiftld:
75	movl	%eax,%ecx
76	popl	%eax
77	movl	%ecx,ans(%eax)
78	movl	%edx,ans+4(%eax)
79
80	ret
81	SET_SIZE(lshiftl)
82