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 without 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
31#include <machine/asm.h>
32__FBSDID("$FreeBSD$");
33
34/*
35 * strcmp(s1, s2)
36 *	return an integer greater than, equal to, or less than 0,
37 *	according as string s1 is greater than, equal to, or less
38 *	than the string s2.
39 *
40 * %eax - pointer to s1
41 * %edx - pointer to s2
42 *
43 * Written by:
44 *	J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc.
45 */
46
47/*
48 * I've unrolled the loop eight times: large enough to make a
49 * significant difference, and small enough not to totally trash the
50 * cache.
51 */
52
53ENTRY(strcmp)
54	movl	0x04(%esp),%eax
55	movl	0x08(%esp),%edx
56	jmp	L2			/* Jump into the loop! */
57
58	.align	2,0x90
59L1:	incl	%eax
60	incl	%edx
61L2:	movb	(%eax),%cl
62	testb	%cl,%cl
63	je	L3
64	cmpb	%cl,(%edx)
65	jne	L3
66	incl	%eax
67	incl	%edx
68	movb	(%eax),%cl
69	testb	%cl,%cl
70	je	L3
71	cmpb	%cl,(%edx)
72	jne	L3
73	incl	%eax
74	incl	%edx
75	movb	(%eax),%cl
76	testb	%cl,%cl
77	je	L3
78	cmpb	%cl,(%edx)
79	jne	L3
80	incl	%eax
81	incl	%edx
82	movb	(%eax),%cl
83	testb	%cl,%cl
84	je	L3
85	cmpb	%cl,(%edx)
86	jne	L3
87	incl	%eax
88	incl	%edx
89	movb	(%eax),%cl
90	testb	%cl,%cl
91	je	L3
92	cmpb	%cl,(%edx)
93	jne	L3
94	incl	%eax
95	incl	%edx
96	movb	(%eax),%cl
97	testb	%cl,%cl
98	je	L3
99	cmpb	%cl,(%edx)
100	jne	L3
101	incl	%eax
102	incl	%edx
103	movb	(%eax),%cl
104	testb	%cl,%cl
105	je	L3
106	cmpb	%cl,(%edx)
107	jne	L3
108	incl	%eax
109	incl	%edx
110	movb	(%eax),%cl
111	testb	%cl,%cl
112	je	L3
113	cmpb	%cl,(%edx)
114	je	L1
115	.align 2, 0x90
116L3:     movzbl  (%eax),%eax             /* unsigned comparison */
117	movzbl  (%edx),%edx
118	subl	%edx,%eax
119	ret
120END(strcmp)
121
122	.section .note.GNU-stack,"",%progbits
123