mirror of https://github.com/acidanthera/audk.git
71 lines
2.0 KiB
NASM
71 lines
2.0 KiB
NASM
;------------------------------------------------------------------------------
|
|
;
|
|
; Copyright (c) 2007, 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:
|
|
;
|
|
; memcpy function
|
|
;
|
|
; Notes:
|
|
;
|
|
;------------------------------------------------------------------------------
|
|
|
|
.686
|
|
.model flat,C
|
|
.mmx
|
|
.code
|
|
|
|
;------------------------------------------------------------------------------
|
|
; VOID *
|
|
; memcpy (
|
|
; IN VOID *Destination,
|
|
; IN VOID *Source,
|
|
; IN UINTN Count
|
|
; );
|
|
;------------------------------------------------------------------------------
|
|
memcpy PROC USES esi edi
|
|
mov esi, [esp + 16] ; esi <- Source
|
|
mov edi, [esp + 12] ; edi <- Destination
|
|
mov edx, [esp + 20] ; edx <- Count
|
|
cmp esi, edi
|
|
je @CopyDone
|
|
cmp edx, 0
|
|
je @CopyDone
|
|
lea eax, [esi + edx - 1] ; eax <- End of Source
|
|
cmp esi, edi
|
|
jae @F
|
|
cmp eax, edi
|
|
jae @CopyBackward ; Copy backward if overlapped
|
|
@@:
|
|
mov ecx, edx
|
|
and edx, 3
|
|
shr ecx, 2
|
|
rep movsd ; Copy as many Dwords as possible
|
|
jmp @CopyBytes
|
|
@CopyBackward:
|
|
mov esi, eax ; esi <- End of Source
|
|
lea edi, [edi + edx - 1] ; edi <- End of Destination
|
|
std
|
|
@CopyBytes:
|
|
mov ecx, edx
|
|
rep movsb ; Copy bytes backward
|
|
cld
|
|
@CopyDone:
|
|
mov eax, [esp + 12]
|
|
ret
|
|
|
|
memcpy ENDP
|
|
|
|
END
|