xref: /openbmc/linux/arch/arc/lib/strcmp-archs.S (revision 9cfc5c90)
1/*
2 * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8
9#include <linux/linkage.h>
10
11ENTRY(strcmp)
12	or	r2, r0, r1
13	bmsk_s	r2, r2, 1
14	brne	r2, 0, @.Lcharloop
15
16;;; s1 and s2 are word aligned
17	ld.ab	r2, [r0, 4]
18
19	mov_s	r12, 0x01010101
20	ror	r11, r12
21	.align  4
22.LwordLoop:
23	ld.ab	r3, [r1, 4]
24	;; Detect NULL char in str1
25	sub	r4, r2, r12
26	ld.ab	r5, [r0, 4]
27	bic	r4, r4, r2
28	and	r4, r4, r11
29	brne.d.nt	r4, 0, .LfoundNULL
30	;; Check if the read locations are the same
31	cmp	r2, r3
32	beq.d	.LwordLoop
33	mov.eq	r2, r5
34
35	;; A match is found, spot it out
36#ifdef __LITTLE_ENDIAN__
37	swape	r3, r3
38	mov_s	r0, 1
39	swape	r2, r2
40#else
41	mov_s	r0, 1
42#endif
43	cmp_s	r2, r3
44	j_s.d	[blink]
45	bset.lo	r0, r0, 31
46
47	.align 4
48.LfoundNULL:
49#ifdef __BIG_ENDIAN__
50	swape	r4, r4
51	swape	r2, r2
52	swape	r3, r3
53#endif
54	;; Find null byte
55	ffs	r0, r4
56	bmsk	r2, r2, r0
57	bmsk	r3, r3, r0
58	swape	r2, r2
59	swape	r3, r3
60	;; make the return value
61	sub.f	r0, r2, r3
62	mov.hi	r0, 1
63	j_s.d	[blink]
64	bset.lo	r0, r0, 31
65
66	.align 4
67.Lcharloop:
68	ldb.ab	r2, [r0, 1]
69	ldb.ab	r3, [r1, 1]
70	nop
71	breq	r2, 0, .Lcmpend
72	breq	r2, r3, .Lcharloop
73
74	.align 4
75.Lcmpend:
76	j_s.d	[blink]
77	sub	r0, r2, r3
78END(strcmp)
79