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
24    .686
25    .model  flat,C
26    .mmx
27    .code
28
29;------------------------------------------------------------------------------
30;  VOID *
31;  EFIAPI
32;  InternalMemCopyMem (
33;    IN VOID   *Destination,
34;    IN VOID   *Source,
35;    IN UINTN  Count
36;    );
37;------------------------------------------------------------------------------
38InternalMemCopyMem  PROC    USES    esi edi
39    mov     esi, [esp + 16]             ; esi <- Source
40    mov     edi, [esp + 12]             ; edi <- Destination
41    mov     edx, [esp + 20]             ; edx <- Count
42    lea     eax, [esi + edx - 1]        ; eax <- End of Source
43    cmp     esi, edi
44    jae     @F
45    cmp     eax, edi                    ; Overlapped?
46    jae     @CopyBackward               ; Copy backward if overlapped
47@@:
48    mov     ecx, edx
49    and     edx, 7
50    shr     ecx, 3                      ; ecx <- # of Qwords to copy
51    jz      @CopyBytes
52    push    eax
53    push    eax
54    movq    [esp], mm0                  ; save mm0
55@@:
56    movq    mm0, [esi]
57    movq    [edi], mm0
58    add     esi, 8
59    add     edi, 8
60    loop    @B
61    movq    mm0, [esp]                  ; restore mm0
62    pop     ecx                         ; stack cleanup
63    pop     ecx                         ; stack cleanup
64    jmp     @CopyBytes
65@CopyBackward:
66    mov     esi, eax                    ; esi <- Last byte in Source
67    lea     edi, [edi + edx - 1]        ; edi <- Last byte in Destination
68    std
69@CopyBytes:
70    mov     ecx, edx
71    rep     movsb
72    cld
73    mov     eax, [esp + 12]
74    ret
75InternalMemCopyMem  ENDP
76
77    END
78