1
|
/*
|
2
|
* linux/arch/arm/lib/memset.S
|
3
|
*
|
4
|
* Copyright (C) 1995-2000 Russell King
|
5
|
*
|
6
|
* This program is free software; you can redistribute it and/or modify
|
7
|
* it under the terms of the GNU General Public License version 2 as
|
8
|
* published by the Free Software Foundation.
|
9
|
*
|
10
|
* ASM optimised string functions
|
11
|
*/
|
12
|
#include <asm/linkage.h>
|
13
|
#include <asm/assembler.h>
|
14
|
|
15
|
.text
|
16
|
.align 5
|
17
|
.word 0
|
18
|
|
19
|
1: subs r2, r2, #4 @ 1 do we have enough
|
20
|
blt 5f @ 1 bytes to align with?
|
21
|
cmp r3, #2 @ 1
|
22
|
strltb r1, [r0], #1 @ 1
|
23
|
strleb r1, [r0], #1 @ 1
|
24
|
strb r1, [r0], #1 @ 1
|
25
|
add r2, r2, r3 @ 1 (r2 = r2 - (4 - r3))
|
26
|
/*
|
27
|
* The pointer is now aligned and the length is adjusted. Try doing the
|
28
|
* memzero again.
|
29
|
*/
|
30
|
|
31
|
ENTRY(memset)
|
32
|
ands r3, r0, #3 @ 1 unaligned?
|
33
|
bne 1b @ 1
|
34
|
/*
|
35
|
* we know that the pointer in r0 is aligned to a word boundary.
|
36
|
*/
|
37
|
orr r1, r1, r1, lsl #8
|
38
|
orr r1, r1, r1, lsl #16
|
39
|
mov r3, r1
|
40
|
cmp r2, #16
|
41
|
blt 4f
|
42
|
/*
|
43
|
* We need an extra register for this loop - save the return address and
|
44
|
* use the LR
|
45
|
*/
|
46
|
str lr, [sp, #-4]!
|
47
|
mov ip, r1
|
48
|
mov lr, r1
|
49
|
|
50
|
2: subs r2, r2, #64
|
51
|
stmgeia r0!, {r1, r3, ip, lr} @ 64 bytes at a time.
|
52
|
stmgeia r0!, {r1, r3, ip, lr}
|
53
|
stmgeia r0!, {r1, r3, ip, lr}
|
54
|
stmgeia r0!, {r1, r3, ip, lr}
|
55
|
bgt 2b
|
56
|
LOADREGS(eqfd, sp!, {pc}) @ Now <64 bytes to go.
|
57
|
/*
|
58
|
* No need to correct the count; we're only testing bits from now on
|
59
|
*/
|
60
|
tst r2, #32
|
61
|
stmneia r0!, {r1, r3, ip, lr}
|
62
|
stmneia r0!, {r1, r3, ip, lr}
|
63
|
tst r2, #16
|
64
|
stmneia r0!, {r1, r3, ip, lr}
|
65
|
ldr lr, [sp], #4
|
66
|
|
67
|
4: tst r2, #8
|
68
|
stmneia r0!, {r1, r3}
|
69
|
tst r2, #4
|
70
|
strne r1, [r0], #4
|
71
|
/*
|
72
|
* When we get here, we've got less than 4 bytes to zero. We
|
73
|
* may have an unaligned pointer as well.
|
74
|
*/
|
75
|
5: tst r2, #2
|
76
|
strneb r1, [r0], #1
|
77
|
strneb r1, [r0], #1
|
78
|
tst r2, #1
|
79
|
strneb r1, [r0], #1
|
80
|
RETINSTR(mov,pc,lr)
|