xref: /linux/arch/csky/abiv2/strlen.S (revision 3eb66e91a25497065c5322b1268cbc3953642227)
1*c5af58b7SGuo Ren/* SPDX-License-Identifier: GPL-2.0 */
2*c5af58b7SGuo Ren// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3*c5af58b7SGuo Ren
4*c5af58b7SGuo Ren#include <linux/linkage.h>
5*c5af58b7SGuo Ren#include "sysdep.h"
6*c5af58b7SGuo Ren
7*c5af58b7SGuo RenENTRY(strlen)
8*c5af58b7SGuo Ren	/* Check if the start addr is aligned.  */
9*c5af58b7SGuo Ren	mov	r3, r0
10*c5af58b7SGuo Ren	andi	r1, r0, 3
11*c5af58b7SGuo Ren	movi	r2, 4
12*c5af58b7SGuo Ren	movi	r0, 0
13*c5af58b7SGuo Ren	bnez	r1, .L_start_not_aligned
14*c5af58b7SGuo Ren
15*c5af58b7SGuo Ren	LABLE_ALIGN
16*c5af58b7SGuo Ren.L_start_addr_aligned:
17*c5af58b7SGuo Ren	/* Check if all the bytes in the word are not zero.  */
18*c5af58b7SGuo Ren	ldw	r1, (r3)
19*c5af58b7SGuo Ren	tstnbz	r1
20*c5af58b7SGuo Ren	bf	.L_string_tail
21*c5af58b7SGuo Ren
22*c5af58b7SGuo Ren	ldw	r1, (r3, 4)
23*c5af58b7SGuo Ren	addi	r0, 4
24*c5af58b7SGuo Ren	tstnbz	r1
25*c5af58b7SGuo Ren	bf	.L_string_tail
26*c5af58b7SGuo Ren
27*c5af58b7SGuo Ren	ldw	r1, (r3, 8)
28*c5af58b7SGuo Ren	addi	r0, 4
29*c5af58b7SGuo Ren	tstnbz	r1
30*c5af58b7SGuo Ren	bf	.L_string_tail
31*c5af58b7SGuo Ren
32*c5af58b7SGuo Ren	ldw	r1, (r3, 12)
33*c5af58b7SGuo Ren	addi	r0, 4
34*c5af58b7SGuo Ren	tstnbz	r1
35*c5af58b7SGuo Ren	bf	.L_string_tail
36*c5af58b7SGuo Ren
37*c5af58b7SGuo Ren	ldw	r1, (r3, 16)
38*c5af58b7SGuo Ren	addi	r0, 4
39*c5af58b7SGuo Ren	tstnbz	r1
40*c5af58b7SGuo Ren	bf	.L_string_tail
41*c5af58b7SGuo Ren
42*c5af58b7SGuo Ren	ldw	r1, (r3, 20)
43*c5af58b7SGuo Ren	addi	r0, 4
44*c5af58b7SGuo Ren	tstnbz	r1
45*c5af58b7SGuo Ren	bf	.L_string_tail
46*c5af58b7SGuo Ren
47*c5af58b7SGuo Ren	ldw	r1, (r3, 24)
48*c5af58b7SGuo Ren	addi	r0, 4
49*c5af58b7SGuo Ren	tstnbz	r1
50*c5af58b7SGuo Ren	bf	.L_string_tail
51*c5af58b7SGuo Ren
52*c5af58b7SGuo Ren	ldw	r1, (r3, 28)
53*c5af58b7SGuo Ren	addi	r0, 4
54*c5af58b7SGuo Ren	tstnbz	r1
55*c5af58b7SGuo Ren	bf	.L_string_tail
56*c5af58b7SGuo Ren
57*c5af58b7SGuo Ren	addi	r0, 4
58*c5af58b7SGuo Ren	addi	r3, 32
59*c5af58b7SGuo Ren	br	.L_start_addr_aligned
60*c5af58b7SGuo Ren
61*c5af58b7SGuo Ren.L_string_tail:
62*c5af58b7SGuo Ren# ifdef __CSKYBE__
63*c5af58b7SGuo Ren	xtrb0	r3, r1
64*c5af58b7SGuo Ren	bez	r3, .L_return
65*c5af58b7SGuo Ren	addi	r0, 1
66*c5af58b7SGuo Ren	xtrb1	r3, r1
67*c5af58b7SGuo Ren	bez	r3, .L_return
68*c5af58b7SGuo Ren	addi	r0, 1
69*c5af58b7SGuo Ren	xtrb2	r3, r1
70*c5af58b7SGuo Ren	bez	r3, .L_return
71*c5af58b7SGuo Ren	addi	r0, 1
72*c5af58b7SGuo Ren# else
73*c5af58b7SGuo Ren	xtrb3	r3, r1
74*c5af58b7SGuo Ren	bez	r3, .L_return
75*c5af58b7SGuo Ren	addi	r0, 1
76*c5af58b7SGuo Ren	xtrb2	r3, r1
77*c5af58b7SGuo Ren	bez	r3, .L_return
78*c5af58b7SGuo Ren	addi	r0, 1
79*c5af58b7SGuo Ren	xtrb1	r3, r1
80*c5af58b7SGuo Ren	bez	r3, .L_return
81*c5af58b7SGuo Ren	addi	r0, 1
82*c5af58b7SGuo Ren# endif	/* !__CSKYBE__ */
83*c5af58b7SGuo Ren
84*c5af58b7SGuo Ren.L_return:
85*c5af58b7SGuo Ren	rts
86*c5af58b7SGuo Ren
87*c5af58b7SGuo Ren.L_start_not_aligned:
88*c5af58b7SGuo Ren	sub	r2, r2, r1
89*c5af58b7SGuo Ren.L_start_not_aligned_loop:
90*c5af58b7SGuo Ren	ldb	r1, (r3)
91*c5af58b7SGuo Ren	PRE_BNEZAD (r2)
92*c5af58b7SGuo Ren	addi	r3, 1
93*c5af58b7SGuo Ren	bez	r1, .L_return
94*c5af58b7SGuo Ren	addi	r0, 1
95*c5af58b7SGuo Ren	BNEZAD (r2, .L_start_not_aligned_loop)
96*c5af58b7SGuo Ren	br	.L_start_addr_aligned
97*c5af58b7SGuo RenENDPROC(strlen)
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