xref: /OK3568_Linux_fs/u-boot/arch/arc/lib/strlen.S (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1/*
2 * Copyright (C) 2004, 2007-2010, 2011-2014 Synopsys, Inc. All rights reserved.
3 *
4 * SPDX-License-Identifier:	GPL-2.0+
5 */
6
7.global strlen
8.align 4
9strlen:
10	or	%r3, %r0, 7
11	ld	%r2, [%r3, -7]
12	ld.a	%r6, [%r3, -3]
13	mov	%r4, 0x01010101
14	/* uses long immediate */
15#ifdef __LITTLE_ENDIAN__
16	asl_s	%r1, %r0, 3
17	btst_s	%r0, 2
18	asl	%r7, %r4, %r1
19	ror	%r5, %r4
20	sub	%r1, %r2, %r7
21	bic_s	%r1, %r1, %r2
22	mov.eq	%r7, %r4
23	sub	%r12, %r6, %r7
24	bic	%r12, %r12, %r6
25	or.eq	%r12, %r12, %r1
26	and	%r12, %r12, %r5
27	brne	%r12, 0, .Learly_end
28#else /* __BIG_ENDIAN__ */
29	ror	%r5, %r4
30	btst_s	%r0, 2
31	mov_s	%r1, 31
32	sub3	%r7, %r1, %r0
33	sub	%r1, %r2, %r4
34	bic_s	%r1, %r1, %r2
35	bmsk	%r1, %r1, %r7
36	sub	%r12, %r6, %r4
37	bic	%r12, %r12, %r6
38	bmsk.ne	%r12, %r12, %r7
39	or.eq	%r12, %r12, %r1
40	and	%r12, %r12, %r5
41	brne	%r12, 0, .Learly_end
42#endif /* _ENDIAN__ */
43
44.Loop:
45	ld_s	%r2, [%r3, 4]
46	ld.a	%r6, [%r3, 8]
47	/* stall for load result */
48	sub	%r1, %r2, %r4
49	bic_s	%r1, %r1, %r2
50	sub	%r12, %r6, %r4
51	bic	%r12, %r12, %r6
52	or	%r12, %r12, %r1
53	and	%r12, %r12, %r5
54	breq	%r12, 0, .Loop
55.Lend:
56	and.f	%r1, %r1, %r5
57	sub.ne	%r3, %r3, 4
58	mov.eq	%r1, %r12
59#ifdef __LITTLE_ENDIAN__
60	sub_s	%r2, %r1, 1
61	bic_s	%r2, %r2, %r1
62	norm	%r1, %r2
63	sub_s	%r0, %r0, 3
64	lsr_s	%r1, %r1, 3
65	sub	%r0, %r3, %r0
66	j_s.d	[%blink]
67	sub	%r0, %r0, %r1
68#else /* __BIG_ENDIAN__ */
69	lsr_s	%r1, %r1, 7
70	mov.eq	%r2, %r6
71	bic_s	%r1, %r1, %r2
72	norm	%r1, %r1
73	sub	%r0, %r3, %r0
74	lsr_s	%r1, %r1, 3
75	j_s.d	[%blink]
76	add	%r0, %r0, %r1
77#endif /* _ENDIAN */
78.Learly_end:
79	b.d	.Lend
80	sub_s.ne %r1, %r1, %r1
81