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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
24    .code
25
26;------------------------------------------------------------------------------
27; VOID *
28; EFIAPI
29; InternalMemCopyMem (
30;   OUT     VOID                      *DestinationBuffer,
31;   IN      CONST VOID                *SourceBuffer,
32;   IN      UINTN                     Length
33;   );
34;------------------------------------------------------------------------------
35InternalMemCopyMem  PROC    USES    rsi rdi
36    mov     rsi, rdx                    ; rsi <- Source
37    mov     rdi, rcx                    ; rdi <- Destination
38    lea     r9, [rsi + r8 - 1]          ; r9 <- End of Source
39    cmp     rsi, rdi
40    mov     rax, rdi                    ; rax <- Destination as return value
41    jae     @F
42    cmp     r9, rdi
43    jae     @CopyBackward               ; Copy backward if overlapped
44@@:
45    mov     rcx, r8
46    and     r8, 7
47    shr     rcx, 3                      ; rcx <- # of Qwords to copy
48    jz      @CopyBytes
49    DB      49h, 0fh, 7eh, 0c2h         ; movd r10, mm0 (Save mm0 in r10)
50@@:
51    DB      0fh, 6fh, 06h               ; movd mm0, [rsi]
52    DB      0fh, 0e7h, 07h              ; movntq [rdi], mm0
53    add     rsi, 8
54    add     rdi, 8
55    loop    @B
56    mfence
57    DB      49h, 0fh, 6eh, 0c2h         ; movd mm0, r10 (Restore mm0)
58    jmp     @CopyBytes
59@CopyBackward:
60    mov     rsi, r9                     ; rsi <- End of Source
61    lea     rdi, [rdi + r8 - 1]         ; rdi <- End of Destination
62    std                                 ; set direction flag
63@CopyBytes:
64    mov     rcx, r8
65    rep     movsb                       ; Copy bytes backward
66    cld
67    ret
68InternalMemCopyMem  ENDP
69
70    END
71