MdePkg/Library/BaseMemoryLibOptPei/Ia32/CopyMem.S File Reference
Detailed Description
#------------------------------------------------------------------------------
#
# Copyright (c) 2006 - 2008, 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.S
#
# Abstract:
#
# CopyMem function
#
# Notes:
#
#------------------------------------------------------------------------------
ASM_GLOBAL
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
cmpl esi, edi
je L_CopyDone
cmpl $0, edx
je L_CopyDone
leal -1(esi, edx), eax # eax <- End of Source
cmpl edi, esi
jae L_CopyBytes
cmpl edi, eax
jb L_CopyBytes # Copy backward if overlapped
movl eax, esi # esi <- End of Source
leal -1(edi, edx), edi # edi <- End of Destination
std
L_CopyBytes:
movl edx, ecx
rep
movsb # Copy bytes backward
cld
L_CopyDone:
movl 12(esp), eax # eax <- Destination as return value
pop edi
pop esi
ret