aboutsummaryrefslogtreecommitdiff
path: root/arch/arc/lib/strlen.S
blob: 666e22c0d541bf43a6de94bc87ede8f871a34997 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
/*
 * Copyright (C) 2004, 2007-2010, 2011-2014 Synopsys, Inc. All rights reserved.
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

.global strlen
.align 4
strlen:
	or	%r3, %r0, 7
	ld	%r2, [%r3, -7]
	ld.a	%r6, [%r3, -3]
	mov	%r4, 0x01010101
	/* uses long immediate */
#ifdef __LITTLE_ENDIAN__
	asl_s	%r1, %r0, 3
	btst_s	%r0, 2
	asl	%r7, %r4, %r1
	ror	%r5, %r4
	sub	%r1, %r2, %r7
	bic_s	%r1, %r1, %r2
	mov.eq	%r7, %r4
	sub	%r12, %r6, %r7
	bic	%r12, %r12, %r6
	or.eq	%r12, %r12, %r1
	and	%r12, %r12, %r5
	brne	%r12, 0, .Learly_end
#else /* __BIG_ENDIAN__ */
	ror	%r5, %r4
	btst_s	%r0, 2
	mov_s	%r1, 31
	sub3	%r7, %r1, %r0
	sub	%r1, %r2, %r4
	bic_s	%r1, %r1, %r2
	bmsk	%r1, %r1, %r7
	sub	%r12, %r6, %r4
	bic	%r12, %r12, %r6
	bmsk.ne	%r12, %r12, %r7
	or.eq	%r12, %r12, %r1
	and	%r12, %r12, %r5
	brne	%r12, 0, .Learly_end
#endif /* _ENDIAN__ */

.Loop:
	ld_s	%r2, [%r3, 4]
	ld.a	%r6, [%r3, 8]
	/* stall for load result */
	sub	%r1, %r2, %r4
	bic_s	%r1, %r1, %r2
	sub	%r12, %r6, %r4
	bic	%r12, %r12, %r6
	or	%r12, %r12, %r1
	and	%r12, %r12, %r5
	breq	%r12, 0, .Loop
.Lend:
	and.f	%r1, %r1, %r5
	sub.ne	%r3, %r3, 4
	mov.eq	%r1, %r12
#ifdef __LITTLE_ENDIAN__
	sub_s	%r2, %r1, 1
	bic_s	%r2, %r2, %r1
	norm	%r1, %r2
	sub_s	%r0, %r0, 3
	lsr_s	%r1, %r1, 3
	sub	%r0, %r3, %r0
	j_s.d	[%blink]
	sub	%r0, %r0, %r1
#else /* __BIG_ENDIAN__ */
	lsr_s	%r1, %r1, 7
	mov.eq	%r2, %r6
	bic_s	%r1, %r1, %r2
	norm	%r1, %r1
	sub	%r0, %r3, %r0
	lsr_s	%r1, %r1, 3
	j_s.d	[%blink]
	add	%r0, %r0, %r1
#endif /* _ENDIAN */
.Learly_end:
	b.d	.Lend
	sub_s.ne %r1, %r1, %r1