xref: /OK3568_Linux_fs/kernel/arch/csky/abiv2/strlen.S (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun/* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3*4882a593Smuzhiyun
4*4882a593Smuzhiyun#include <linux/linkage.h>
5*4882a593Smuzhiyun#include "sysdep.h"
6*4882a593Smuzhiyun
7*4882a593SmuzhiyunENTRY(strlen)
8*4882a593Smuzhiyun	/* Check if the start addr is aligned.  */
9*4882a593Smuzhiyun	mov	r3, r0
10*4882a593Smuzhiyun	andi	r1, r0, 3
11*4882a593Smuzhiyun	movi	r2, 4
12*4882a593Smuzhiyun	movi	r0, 0
13*4882a593Smuzhiyun	bnez	r1, .L_start_not_aligned
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun	LABLE_ALIGN
16*4882a593Smuzhiyun.L_start_addr_aligned:
17*4882a593Smuzhiyun	/* Check if all the bytes in the word are not zero.  */
18*4882a593Smuzhiyun	ldw	r1, (r3)
19*4882a593Smuzhiyun	tstnbz	r1
20*4882a593Smuzhiyun	bf	.L_string_tail
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun	ldw	r1, (r3, 4)
23*4882a593Smuzhiyun	addi	r0, 4
24*4882a593Smuzhiyun	tstnbz	r1
25*4882a593Smuzhiyun	bf	.L_string_tail
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun	ldw	r1, (r3, 8)
28*4882a593Smuzhiyun	addi	r0, 4
29*4882a593Smuzhiyun	tstnbz	r1
30*4882a593Smuzhiyun	bf	.L_string_tail
31*4882a593Smuzhiyun
32*4882a593Smuzhiyun	ldw	r1, (r3, 12)
33*4882a593Smuzhiyun	addi	r0, 4
34*4882a593Smuzhiyun	tstnbz	r1
35*4882a593Smuzhiyun	bf	.L_string_tail
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun	ldw	r1, (r3, 16)
38*4882a593Smuzhiyun	addi	r0, 4
39*4882a593Smuzhiyun	tstnbz	r1
40*4882a593Smuzhiyun	bf	.L_string_tail
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun	ldw	r1, (r3, 20)
43*4882a593Smuzhiyun	addi	r0, 4
44*4882a593Smuzhiyun	tstnbz	r1
45*4882a593Smuzhiyun	bf	.L_string_tail
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun	ldw	r1, (r3, 24)
48*4882a593Smuzhiyun	addi	r0, 4
49*4882a593Smuzhiyun	tstnbz	r1
50*4882a593Smuzhiyun	bf	.L_string_tail
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun	ldw	r1, (r3, 28)
53*4882a593Smuzhiyun	addi	r0, 4
54*4882a593Smuzhiyun	tstnbz	r1
55*4882a593Smuzhiyun	bf	.L_string_tail
56*4882a593Smuzhiyun
57*4882a593Smuzhiyun	addi	r0, 4
58*4882a593Smuzhiyun	addi	r3, 32
59*4882a593Smuzhiyun	br	.L_start_addr_aligned
60*4882a593Smuzhiyun
61*4882a593Smuzhiyun.L_string_tail:
62*4882a593Smuzhiyun# ifdef __CSKYBE__
63*4882a593Smuzhiyun	xtrb0	r3, r1
64*4882a593Smuzhiyun	bez	r3, .L_return
65*4882a593Smuzhiyun	addi	r0, 1
66*4882a593Smuzhiyun	xtrb1	r3, r1
67*4882a593Smuzhiyun	bez	r3, .L_return
68*4882a593Smuzhiyun	addi	r0, 1
69*4882a593Smuzhiyun	xtrb2	r3, r1
70*4882a593Smuzhiyun	bez	r3, .L_return
71*4882a593Smuzhiyun	addi	r0, 1
72*4882a593Smuzhiyun# else
73*4882a593Smuzhiyun	xtrb3	r3, r1
74*4882a593Smuzhiyun	bez	r3, .L_return
75*4882a593Smuzhiyun	addi	r0, 1
76*4882a593Smuzhiyun	xtrb2	r3, r1
77*4882a593Smuzhiyun	bez	r3, .L_return
78*4882a593Smuzhiyun	addi	r0, 1
79*4882a593Smuzhiyun	xtrb1	r3, r1
80*4882a593Smuzhiyun	bez	r3, .L_return
81*4882a593Smuzhiyun	addi	r0, 1
82*4882a593Smuzhiyun# endif	/* !__CSKYBE__ */
83*4882a593Smuzhiyun
84*4882a593Smuzhiyun.L_return:
85*4882a593Smuzhiyun	rts
86*4882a593Smuzhiyun
87*4882a593Smuzhiyun.L_start_not_aligned:
88*4882a593Smuzhiyun	sub	r2, r2, r1
89*4882a593Smuzhiyun.L_start_not_aligned_loop:
90*4882a593Smuzhiyun	ldb	r1, (r3)
91*4882a593Smuzhiyun	PRE_BNEZAD (r2)
92*4882a593Smuzhiyun	addi	r3, 1
93*4882a593Smuzhiyun	bez	r1, .L_return
94*4882a593Smuzhiyun	addi	r0, 1
95*4882a593Smuzhiyun	BNEZAD (r2, .L_start_not_aligned_loop)
96*4882a593Smuzhiyun	br	.L_start_addr_aligned
97*4882a593SmuzhiyunENDPROC(strlen)
98