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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     .386
     25     .model  flat,C
     26     .code
     27 
     28 ;------------------------------------------------------------------------------
     29 ;  VOID *
     30 ;  InternalMemCopyMem (
     31 ;    IN VOID   *Destination,
     32 ;    IN VOID   *Source,
     33 ;    IN UINTN  Count
     34 ;    )
     35 ;------------------------------------------------------------------------------
     36 InternalMemCopyMem  PROC    USES    esi edi
     37     mov     esi, [esp+16]                ; esi <- Source
     38     mov     edi, [esp+12]                ; edi <- Destination
     39     mov     edx, [esp+20]                ; edx <- Count
     40     cmp     esi, edi
     41     je      @CopyDone
     42     cmp     edx, 0
     43     je      @CopyDone
     44     lea     eax, [esi + edx - 1]         ; eax <- End of Source
     45     cmp     esi, edi
     46     jae     @CopyBytes
     47     cmp     eax, edi
     48     jb      @CopyBytes                   ; Copy backward if overlapped
     49     mov     esi, eax                     ; esi <- End of Source
     50     lea     edi, [edi + edx - 1]         ; edi <- End of Destination
     51     std
     52 @CopyBytes:
     53     mov     ecx, edx
     54     rep     movsb                        ; Copy bytes backward
     55     cld
     56 @CopyDone:
     57     mov     eax, [esp + 12]             ; eax <- Destination as return value
     58     ret
     59 InternalMemCopyMem  ENDP
     60 
     61     END
     62