strcpy.S revision 50476 
1/*
2 * Copyright (c) 1993 Winning Strategies, Inc.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *      This product includes software developed by Winning Strategies, Inc.
16 * 4. The name of the author may not be used to endorse or promote products
17 *    derived from this software withough specific prior written permission
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 *
30 * $FreeBSD: head/lib/libc/i386/string/strcpy.S 50476 1999-08-28 00:22:10Z peter $
31 */
32
33#if defined(LIBC_RCS) && !defined(lint)
34	.text
35        .asciz "$FreeBSD: head/lib/libc/i386/string/strcpy.S 50476 1999-08-28 00:22:10Z peter $"
36#endif /* LIBC_RCS and not lint */
37
38#include "DEFS.h"
39
40/*
41 * strcpy (dst, src)
42 *	copy the string src to dst.
43 *
44 * Written by:
45 *	J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc.
46 */
47
48/*
49 * I've unrolled the loop eight times: large enough to make a
50 * significant difference, and small enough not to totally trash the
51 * cashe.
52 */
53
54ENTRY(strcpy)
55	movl	4(%esp),%ecx		/* dst address */
56	movl	8(%esp),%edx		/* src address */
57	pushl	%ecx			/* push dst address */
58
59	.align 2,0x90
60L1:	movb	(%edx),%al		/* unroll loop, but not too much */
61	movb	%al,(%ecx)
62	testb	%al,%al
63	je	L2
64	movb	1(%edx),%al
65	movb	%al,1(%ecx)
66	testb	%al,%al
67	je	L2
68	movb	2(%edx),%al
69	movb	%al,2(%ecx)
70	testb	%al,%al
71	je	L2
72	movb	3(%edx),%al
73	movb	%al,3(%ecx)
74	testb	%al,%al
75	je	L2
76	movb	4(%edx),%al
77	movb	%al,4(%ecx)
78	testb	%al,%al
79	je	L2
80	movb	5(%edx),%al
81	movb	%al,5(%ecx)
82	testb	%al,%al
83	je	L2
84	movb	6(%edx),%al
85	movb	%al,6(%ecx)
86	testb	%al,%al
87	je	L2
88	movb	7(%edx),%al
89	movb	%al,7(%ecx)
90	addl	$8,%edx
91	addl	$8,%ecx
92	testb	%al,%al
93	jne	L1
94L2:	popl	%eax			/* pop dst address */
95	ret
96