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
|
/*
* ====================================================
* Copyright (C) 1998 by Cygnus Solutions. All rights reserved.
*
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
#include "i386mach.h"
.global SYM (memmove)
SYM (memmove):
pushl ebp
movl esp,ebp
pushl esi
pushl edi
pushl ebx
movl 8(ebp),edi
movl 16(ebp),ecx
movl 12(ebp),esi
/* check for destructive overlap (src < dst && dst < src + length) */
cld
cmpl edi,esi
jae .L2
leal -1(ecx,esi),ebx
cmpl ebx,edi
ja .L2
/* destructive overlap, must copy backwards...do it a byte at a time since it is uncommon */
decl edi
movl ebx,esi
addl ecx,edi
std
jmp BYTEMOVE
.L2:
#ifndef __OPTIMIZE_SIZE__
/* non-destructive overlap so we can try and move 4 bytes at a time */
movl esi,eax
orl edi,eax
testb $3,al
jne BYTEMOVE
shrl $2,ecx
rep
movsl
/* calculate any remainder bytes after moving doublewords */
movl 16(ebp),ecx
andl $3,ecx
#endif /* not __OPTIMIZE_SIZE__ */
/* move any unaligned bytes or remainder bytes, one at a time */
BYTEMOVE:
rep
movsb
movl 8(ebp),eax
leal -12(ebp),esp
popl ebx
popl edi
popl esi
leave
ret
|
