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Viewing changes to src/VBox/Devices/EFI/Firmware/MdePkg/Library/BaseMemoryLibRepStr/X64/CopyMem.asm

  • Committer: Package Import Robot
  • Author(s): Gianfranco Costamagna
  • Date: 2016-02-23 14:28:26 UTC
  • Revision ID: package-import@ubuntu.com-20160223142826-bdu69el2z6wa2a44
Tags: upstream-4.3.36-dfsg
Import upstream version 4.3.36-dfsg

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src/VBox/Devices/EFI/Firmware/MdePkg/Library/BaseMemoryLibRepStr/X64/CopyMem.asm
 
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;------------------------------------------------------------------------------
 
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;
 
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; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>
 
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; This program and the accompanying materials
 
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; are licensed and made available under the terms and conditions of the BSD License
 
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; which accompanies this distribution.  The full text of the license may be found at
 
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; http://opensource.org/licenses/bsd-license.php.
 
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;
 
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; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
 
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; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 
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;
 
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; Module Name:
 
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;
 
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;   CopyMem.Asm
 
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;
 
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; Abstract:
 
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;
 
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;   CopyMem function
 
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;
 
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; Notes:
 
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;
 
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;------------------------------------------------------------------------------
 
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    .code
 
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;------------------------------------------------------------------------------
 
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;  VOID *
 
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;  EFIAPI
 
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;  InternalMemCopyMem (
 
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;    IN VOID   *Destination,
 
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;    IN VOID   *Source,
 
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;    IN UINTN  Count
 
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;    )
 
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;------------------------------------------------------------------------------
 
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InternalMemCopyMem  PROC    USES    rsi rdi
 
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    mov     rsi, rdx                    ; rsi <- Source
 
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    mov     rdi, rcx                    ; rdi <- Destination
 
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    lea     r9, [rsi + r8 - 1]          ; r9 <- End of Source
 
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    cmp     rsi, rdi
 
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    mov     rax, rdi                    ; rax <- Destination as return value
 
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    jae     @F
 
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    cmp     r9, rdi
 
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    jae     @CopyBackward               ; Copy backward if overlapped
 
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@@:
 
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    mov     rcx, r8
 
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    and     r8, 7
 
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    shr     rcx, 3
 
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    rep     movsq                       ; Copy as many Qwords as possible
 
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    jmp     @CopyBytes
 
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@CopyBackward:
 
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    mov     rsi, r9                     ; rsi <- End of Source
 
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    lea     rdi, [rdi + r8 - 1]         ; esi <- End of Destination
 
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    std                                 ; set direction flag
 
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@CopyBytes:
 
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    mov     rcx, r8
 
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    rep     movsb                       ; Copy bytes backward
 
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    cld
 
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    ret
 
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InternalMemCopyMem  ENDP
 
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    END