mirror of https://github.com/acidanthera/audk.git
79 lines
2.1 KiB
C
79 lines
2.1 KiB
C
/*++
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Copyright (c) 2007, Intel Corporation
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All rights reserved. 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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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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Module Name:
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EfiCopyMemRep4.c
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Abstract:
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This is the code that uses rep movsd CopyMem service
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--*/
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#include "Tiano.h"
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VOID
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EfiCommonLibCopyMem (
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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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Routine Description:
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Copy Length bytes from Source to Destination.
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Arguments:
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Destination - Target of copy
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Source - Place to copy from
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Length - Number of bytes to copy
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Returns:
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None
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--*/
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{
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__asm {
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mov esi, Source ; esi <- Source
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mov edi, Destination ; edi <- Destination
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mov edx, Count ; edx <- Count
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cmp esi, edi
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je _CopyDone
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cmp edx, 0
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je _CopyDone
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lea eax, [esi + edx - 1] ; eax <- End of Source
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cmp esi, edi
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jae _CopyDWord
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cmp eax, edi
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jae _CopyBackward ; Copy backward if overlapped
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_CopyDWord:
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mov ecx, edx
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and edx, 3
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shr ecx, 2
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rep movsd ; Copy as many Dwords as possible
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jmp _CopyBytes
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_CopyBackward:
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mov esi, eax ; esi <- End of Source
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lea edi, [edi + edx - 1] ; edi <- End of Destination
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std
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_CopyBytes:
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mov ecx, edx
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rep movsb ; Copy bytes backward
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cld
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_CopyDone:
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}
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} |