1/*	$OpenBSD: strcat.S,v 1.8 2005/08/07 11:30:38 espie Exp $ */
2/*
3 * Written by J.T. Conklin <jtc@netbsd.org>.
4 * Public domain.
5 */
6
7#include <private/bionic_asm.h>
8
9#if defined(APIWARN)
10#APP
11	.section .gnu.warning.strcat
12	.ascii "warning: strcat() is almost always misused, please use strlcat()"
13#NO_APP
14#endif
15
16/*
17 * NOTE: I've unrolled the loop eight times: large enough to make a
18 * significant difference, and small enough not to totally trash the
19 * cache.
20 */
21
22ENTRY(strcat)
23	pushl	%edi			/* save edi */
24	movl	8(%esp),%edi		/* dst address */
25	movl	12(%esp),%edx		/* src address */
26	pushl	%edi			/* push destination address */
27
28	cld				/* set search forward */
29	xorl	%eax,%eax		/* set search for null terminator */
30	movl	$-1,%ecx		/* set search for lots of characters */
31	repne				/* search! */
32	scasb
33
34	leal	-1(%edi),%ecx		/* correct dst address */
35
36	.align 2,0x90
37L1:	movb	(%edx),%al		/* unroll loop, but not too much */
38	movb	%al,(%ecx)
39	testb	%al,%al
40	jz	L2
41	movb	1(%edx),%al
42	movb	%al,1(%ecx)
43	testb	%al,%al
44	jz	L2
45	movb	2(%edx),%al
46	movb	%al,2(%ecx)
47	testb	%al,%al
48	jz	L2
49	movb	3(%edx),%al
50	movb	%al,3(%ecx)
51	testb	%al,%al
52	jz	L2
53	movb	4(%edx),%al
54	movb	%al,4(%ecx)
55	testb	%al,%al
56	jz	L2
57	movb	5(%edx),%al
58	movb	%al,5(%ecx)
59	testb	%al,%al
60	jz	L2
61	movb	6(%edx),%al
62	movb	%al,6(%ecx)
63	testb	%al,%al
64	jz	L2
65	movb	7(%edx),%al
66	movb	%al,7(%ecx)
67	addl	$8,%edx
68	addl	$8,%ecx
69	testb	%al,%al
70	jnz	L1
71L2:	popl	%eax			/* pop destination address */
72	popl	%edi			/* restore edi */
73	ret
74END(strcat)
75