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1#------------------------------------------------------------------------------
2#
3# Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>
4# This program and the accompanying materials
5# are licensed and made available under the terms and conditions of the BSD License
6# which accompanies this distribution.  The full text of the license may be found at
7# http://opensource.org/licenses/bsd-license.php.
8#
9# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
10# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
11#
12# Module Name:
13#
14#   CopyMem.asm
15#
16# Abstract:
17#
18#   CopyMem function
19#
20# Notes:
21#
22#------------------------------------------------------------------------------
23
24ASM_GLOBAL ASM_PFX(InternalMemCopyMem)
25
26#------------------------------------------------------------------------------
27#  VOID *
28#  EFIAPI
29#  InternalMemCopyMem (
30#    IN VOID   *Destination,
31#    IN VOID   *Source,
32#    IN UINTN  Count
33#    );
34#------------------------------------------------------------------------------
35ASM_PFX(InternalMemCopyMem):
36    push    %esi
37    push    %edi
38    movl    16(%esp), %esi              # esi <- Source
39    movl    12(%esp), %edi              # edi <- Destination
40    movl    20(%esp), %edx              # edx <- Count
41    leal    -1(%esi,%edx,), %eax        # eax <- End of Source
42    cmpl    %edi, %esi
43    jae     L0
44    cmpl    %edi, %eax                  # Overlapped?
45    jae     L_CopyBackward              # Copy backward if overlapped
46L0:
47    xorl    %ecx, %ecx
48    subl    %esi, %ecx
49    andl    $7, %ecx                    # ecx + esi aligns on 8-byte boundary
50    jz      L1
51    cmpl    %edx, %ecx
52    cmova   %edx, %ecx
53    subl    %ecx, %edx                  # edx <- remaining bytes to copy
54    rep
55    movsb
56L1:
57    movl    %edx, %ecx
58    andl    $7, %edx
59    shrl    $3, %ecx                    # ecx <- # of Qwords to copy
60    jz      L_CopyBytes
61    pushl   %eax
62    pushl   %eax
63    movq    %mm0, (%esp)                # save mm0
64L2:
65    movq    (%esi), %mm0
66    movq    %mm0, (%edi)
67    addl    $8, %esi
68    addl    $8, %edi
69    loop    L2
70    movq    (%esp), %mm0                # restore mm0
71    popl    %ecx                        # stack cleanup
72    popl    %ecx                        # stack cleanup
73    jmp     L_CopyBytes
74L_CopyBackward:
75    movl    %eax, %esi                  # esi <- Last byte in Source
76    leal    -1(%edi,%edx,), %edi        # edi <- Last byte in Destination
77    std
78L_CopyBytes:
79    movl    %edx, %ecx
80    rep
81    movsb
82    cld
83    movl    12(%esp), %eax
84    pop     %edi
85    pop     %esi
86    ret
87