;------------------------------------------------------------------------------ | |
; | |
; 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 |