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
|
;------------------------------------------------------------------------------
;
; 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:
;
;------------------------------------------------------------------------------
.code
InternalMemCopyMem PROC USES rsi rdi
mov rsi, rdx ; rsi <- Source
mov rdi, rcx ; rdi <- Destination
lea r9, [rdi + r8 - 1] ; r9 <- End of Destination
cmp rsi, rdi
mov rax, rdi ; rax <- Destination as return value
jae @F
cmp r9, rsi
jae @CopyBackward ; Copy backward if overlapped
@@:
xor rcx, rcx
sub rcx, rsi
and rcx, 7 ; rcx + rsi aligns on 8-byte boundary
jz @F
cmp rcx, r8
cmova rcx, r8
sub r8, rcx ; r8 <- remaining bytes to copy
rep movsb
@@:
mov rcx, r8
and r8, 7
shr rcx, 3 ; rcx <- # of Qwords to copy
jz @CopyBytes
DB 49h, 0fh, 7eh, 0c2h ; movq r10, mm0 ; save mm0
@@:
DB 48h, 0fh, 6fh, 06h ; movq mm0, [rsi]
DB 48h, 0fh, 0e7h, 07h ; movntq [rdi], mm0
add rsi, 8
add rdi, 8
loop @B
mfence
DB 49h, 0fh, 6eh, 0c2h ; movq mm0, r10 ; restore mm0
jmp @CopyBytes
@CopyBackward:
mov rdi, r9 ; rdi <- End of Destination
lea rsi, [rsi + r8 - 1] ; rsi <- End of Source
std ; set direction flag
@CopyBytes:
mov rcx, r8
rep movsb ; Copy bytes backward
cld
ret
InternalMemCopyMem ENDP
END
|
