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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:
#
#------------------------------------------------------------------------------
.globl ASM_PFX(InternalMemCopyMem)
#------------------------------------------------------------------------------
# VOID *
# EFIAPI
# InternalMemCopyMem (
# IN VOID *Destination,
# IN VOID *Source,
# IN UINTN Count
# );
#------------------------------------------------------------------------------
ASM_PFX(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(%esi,%edx,), %eax # eax <- End of Source
cmpl %edi, %esi
jae L0
cmpl %edi, %eax # Overlapped?
jae L_CopyBackward # Copy backward if overlapped
L0:
xorl %ecx, %ecx
subl %esi, %ecx
andl $7, %ecx # ecx + esi aligns on 8-byte boundary
jz L1
cmpl %edx, %ecx
cmova %edx, %ecx
subl %ecx, %edx # edx <- remaining bytes to copy
rep
movsb
L1:
movl %edx, %ecx
andl $7, %edx
shrl $3, %ecx # ecx <- # of Qwords to copy
jz L_CopyBytes
pushl %eax
pushl %eax
movq %mm0, (%esp) # save mm0
L2:
movq (%esi), %mm0
movq %mm0, (%edi)
addl $8, %esi
addl $8, %edi
loop L2
movq (%esp), %mm0 # restore mm0
popl %ecx # stack cleanup
popl %ecx # stack cleanup
jmp L_CopyBytes
L_CopyBackward:
movl %eax, %esi # esi <- Last byte in Source
leal -1(%edi,%edx,), %edi # edi <- Last byte in Destination
std
L_CopyBytes:
movl %edx, %ecx
rep
movsb
cld
movl 12(%esp), %eax
pop %edi
pop %esi
ret
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