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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:
;
;------------------------------------------------------------------------------
.686
.model flat,C
.xmm
.code
;------------------------------------------------------------------------------
; VOID *
; _mem_CopyMem (
; 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, [edi + edx - 1] ; eax <- End of Destination
cmp esi, edi
jae @F
cmp eax, esi ; 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 edi, eax ; edi <- Last byte in Destination
lea esi, [esi + edx - 1] ; esi <- Last byte in Source
std
@CopyBytes:
mov ecx, edx
rep movsb
cld
mov eax, [esp + 12] ; eax <- Destination as return value
ret
InternalMemCopyMem ENDP
END
|
