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
75
76
77
78
79
80
81
82
83
84
85
86
|
;------------------------------------------------------------------------------
;
; Copyright (c) 2006, Intel Corporation
; All rights reserved. This program and the accompanying materials
; are licensed and made available under the terms and conditions of the BSD License
; which accompanies this distribution. The full text of the license may be found at
; http://opensource.org/licenses/bsd-license.php
;
; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
;
; Module Name:
;
; CopyMem.asm
;
; Abstract:
;
; CopyMem function
;
; Notes:
;
;------------------------------------------------------------------------------
.686
.model flat,C
.xmm
.code
;------------------------------------------------------------------------------
; VOID *
; _mem_CopyMem (
; IN VOID *Destination,
; IN VOID *Source,
; IN UINTN Count
; )
;------------------------------------------------------------------------------
InternalMemCopyMem PROC USES esi edi
mov esi, [esp + 16] ; esi <- Source
mov edi, [esp + 12] ; edi <- Destination
mov edx, [esp + 20] ; edx <- Count
lea eax, [edi + edx - 1] ; eax <- End of Destination
cmp esi, edi
jae @F
cmp eax, esi ; Overlapped?
jae @CopyBackward ; Copy backward if overlapped
@@:
xor ecx, ecx
sub ecx, esi
and ecx, 7 ; ecx + esi aligns on 8-byte boundary
jz @F
cmp ecx, edx
cmova ecx, edx
sub edx, ecx ; edx <- remaining bytes to copy
rep movsb
@@:
mov ecx, edx
and edx, 7
shr ecx, 3 ; ecx <- # of Qwords to copy
jz @CopyBytes
push eax
push eax
movq [esp], mm0 ; save mm0
@@:
movq mm0, [esi]
movntq [edi], mm0
add esi, 8
add edi, 8
loop @B
mfence
movq mm0, [esp] ; restore mm0
pop ecx ; stack cleanup
pop ecx ; stack cleanup
jmp @CopyBytes
@CopyBackward:
mov edi, eax ; edi <- Last byte in Destination
lea esi, [esi + edx - 1] ; esi <- Last byte in Source
std
@CopyBytes:
mov ecx, edx
rep movsb
cld
mov eax, [esp + 12]
ret
InternalMemCopyMem ENDP
END
|
