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
87
88
89
90
|
#------------------------------------------------------------------------------
#
# 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
# )
#------------------------------------------------------------------------------
.global _InternalMemCopyMem
_InternalMemCopyMem:
push %esi
push %edi
movl 16(%esp), %esi # esi <- Source
movl 12(%esp), %edi # edi <- Destination
movl 20(%esp), %edx # edx <- Count
leal -1(%edi,%edx,), %eax # eax <- End of Destination
cmpl %edi, %esi
jae L0
cmpl %esi, %eax # Overlapped?
jae @CopyBackward # Copy backward if overlapped
L0:
xorl %ecx, %ecx
subl %esi, %ecx
andl $7, %ecx # ecx + esi aligns on 8-byte boundary
jz L1
cmpl %edx, %ecx
cmova %edx, %ecx
subl %ecx, %edx # edx <- remaining bytes to copy
rep
movsb
L1:
movl %edx, %ecx
andl $7, %edx
shrl $3, %ecx # ecx <- # of Qwords to copy
jz @CopyBytes
pushl %eax
pushl %eax
movq %mm0, (%esp) # save mm0
L2:
movq (%esi), %mm0
movntq %mm0, (%edi)
addl $8, %esi
addl $8, %edi
loop L2
mfence
movq (%esp), %mm0 # restore mm0
popl %ecx # stack cleanup
popl %ecx # stack cleanup
jmp @CopyBytes
@CopyBackward:
movl %eax, %edi # edi <- Last byte in Destination
leal -1(%esi,%edx,), %esi # esi <- Last byte in Source
std
@CopyBytes:
movl %edx, %ecx
rep
movsb
cld
movl 12(%esp), %eax
pop %edi
pop %esi
ret
|
