;------------------------------------------------------------------------------

;

; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>

; 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:

;

;------------------------------------------------------------------------------

.686

.model flat,C

.xmm

.code

;------------------------------------------------------------------------------

; VOID *

; InternalMemCopyMem (

; IN VOID *Destination,

; IN VOID *Source,

; IN UINTN Count

; );

;------------------------------------------------------------------------------

InternalMemCopyMem PROC USES esi edi

mov esi, [esp + 16] ; esi <- Source

mov edi, [esp + 12] ; edi <- Destination

mov edx, [esp + 20] ; edx <- Count

lea eax, [esi + edx - 1] ; eax <- End of Source

cmp esi, edi

jae @F

cmp eax, edi ; Overlapped?

jae @CopyBackward ; Copy backward if overlapped

@@:

xor ecx, ecx

sub ecx, edi

and ecx, 15 ; ecx + edi aligns on 16-byte boundary

jz @F

cmp ecx, edx

cmova ecx, edx

sub edx, ecx ; edx <- remaining bytes to copy

rep movsb

@@:

mov ecx, edx

and edx, 15

shr ecx, 4 ; ecx <- # of DQwords to copy

jz @CopyBytes

add esp, -16

movdqu [esp], xmm0 ; save xmm0

@@:

movdqu xmm0, [esi] ; esi may not be 16-bytes aligned

movntdq [edi], xmm0 ; edi should be 16-bytes aligned

add esi, 16

add edi, 16

loop @B

mfence

movdqu xmm0, [esp] ; restore xmm0

add esp, 16 ; stack cleanup

jmp @CopyBytes

@CopyBackward:

mov esi, eax ; esi <- Last byte in Source

lea edi, [edi + edx - 1] ; edi <- Last byte in Destination

std

@CopyBytes:

mov ecx, edx

rep movsb

cld

mov eax, [esp + 12] ; eax <- Destination as return value

ret

InternalMemCopyMem ENDP

END