memmove.S revision 21673 
1/*-
2 * Copyright (c) 1990 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *	This product includes software developed by the University of
18 *	California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 *	$FreeBSD: head/lib/libc/i386/string/memmove.S 21673 1997-01-14 07:20:47Z jkh $
36 */
37
38#if defined(LIBC_RCS) && !defined(lint)
39	.text
40        .asciz "$FreeBSD: head/lib/libc/i386/string/memmove.S 21673 1997-01-14 07:20:47Z jkh $"
41#endif /* LIBC_RCS and not lint */
42
43#include "DEFS.h"
44
45	/*
46	 * (ov)bcopy (src,dst,cnt)
47	 *  ws@tools.de     (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
48	 */
49
50ALTENTRY(memcpy)
51ENTRY(memmove)
52	pushl	%esi
53	pushl	%edi
54	movl	12(%esp),%edi
55	movl	16(%esp),%esi
56	movl	20(%esp),%ecx
57	movl	%edi,%eax
58	subl	%esi,%eax
59	cmpl	%ecx,%eax
60	jb	1f
61	cld			/* nope, copy forwards. */
62	shrl	$2,%ecx		/* copy by words */
63	rep
64	movsl
65	movl	20(%esp),%ecx
66	andl	$3,%ecx		/* any bytes left? */
67	rep
68	movsb
69	movl	12(%esp),%eax
70	popl	%edi
71	popl	%esi
72	ret
731:
74	addl	%ecx,%edi	/* copy backwards. */
75	addl	%ecx,%esi
76	decl	%edi
77	decl	%esi
78	andl	$3,%ecx		/* any fractional bytes? */
79	std
80	rep
81	movsb
82	movl	20(%esp),%ecx	/* copy remainder by words */
83	shrl	$2,%ecx
84	subl	$3,%esi
85	subl	$3,%edi
86	rep
87	movsl
88	movl	12(%esp),%eax
89	popl	%edi
90	popl	%esi
91	cld
92	ret
93