strcat.S revision 5790 
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 *	$Id: strcat.S,v 1.1 1994/08/05 01:18:32 wollman Exp $
31 */
32
33#if defined(LIBC_RCS) && !defined(lint)
34	.text
35        .asciz "$Id: strcat.S,v 1.1 1994/08/05 01:18:32 wollman Exp $"
36#endif /* LIBC_RCS and not lint */
37
38#include "DEFS.h"
39
40/*
41 * strcat(s, append)
42 *	append a copy of the null-terminated string "append" to the end
43 *	of the null-terminated string s, then add a terminating `\0'.
44 *
45 * Written by:
46 *	J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc.
47 */
48
49/*
50 * I've unrolled the loop eight times: large enough to make a
51 * significant difference, and small enough not to totally trash the
52 * cashe.
53 */
54
55ENTRY(strcat)
56	pushl	%edi			/* save edi */
57	movl	8(%esp),%edi		/* dst address */
58	movl	12(%esp),%edx		/* src address */
59	pushl	%edi			/* push destination address */
60
61	cld				/* set search forward */
62	xorl	%eax,%eax		/* set search for null terminator */
63	movl	$-1,%ecx		/* set search for lots of characters */
64	repne				/* search! */
65	scasb
66
67	leal	-1(%edi),%ecx		/* correct dst address */
68
69	.align 2,0x90
70L1:	movb	(%edx),%al		/* unroll loop, but not too much */
71	movb	%al,(%ecx)
72	testb	%al,%al
73	je	L2
74	movb	1(%edx),%al
75	movb	%al,1(%ecx)
76	testb	%al,%al
77	je	L2
78	movb	2(%edx),%al
79	movb	%al,2(%ecx)
80	testb	%al,%al
81	je	L2
82	movb	3(%edx),%al
83	movb	%al,3(%ecx)
84	testb	%al,%al
85	je	L2
86	movb	4(%edx),%al
87	movb	%al,4(%ecx)
88	testb	%al,%al
89	je	L2
90	movb	5(%edx),%al
91	movb	%al,5(%ecx)
92	testb	%al,%al
93	je	L2
94	movb	6(%edx),%al
95	movb	%al,6(%ecx)
96	testb	%al,%al
97	je	L2
98	movb	7(%edx),%al
99	movb	%al,7(%ecx)
100	addl	$8,%edx
101	addl	$8,%ecx
102	testb	%al,%al
103	jne	L1
104L2:	popl	%eax			/* pop destination address */
105	popl	%edi			/* restore edi */
106	ret
107