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#------------------------------------------------------------------------------
#
# Copyright (c) 2006, Intel Corporation
# All rights reserved. This program and the accompanying materials
# are licensed and made available under the terms and conditions of the BSD License
# which accompanies this distribution. The full text of the license may be found at
# http://opensource.org/licenses/bsd-license.php
#
# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
#
# Module Name:
#
# CopyMem.Asm
#
# Abstract:
#
# CopyMem function
#
# Notes:
#
#------------------------------------------------------------------------------
.386:
.code:
.global _InternalMemCopyMem
_InternalMemCopyMem:
push %esi
push %edi
movl 16(%esp),%esi # esi <- Source
movl 12(%esp),%edi # edi <- Destination
movl 20(%esp),%edx # edx <- Count
leal -1(%edi,%edx),%eax # eax <- End of Destination
cmpl %edi,%esi
jae L0
cmpl %esi,%eax
jae @CopyBackward # Copy backward if overlapped
L0:
movl %edx,%ecx
andl $3,%edx
shrl $2,%ecx
rep
movsl # Copy as many Dwords as possible
jmp @CopyBytes
@CopyBackward:
movl %eax,%edi # edi <- End of Destination
leal -1(%esi,%edx),%esi # esi <- End of Source
std
@CopyBytes:
movl %edx,%ecx
rep
movsb # Copy bytes backward
cld
movl 12(%esp),%eax # eax <- Destination as return value
pop %edi
pop %esi
ret
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