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

;

; 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:

;

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

.code

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

; VOID *

; EFIAPI

; InternalMemCopyMem (

; IN VOID *Destination,

; IN VOID *Source,

; IN UINTN Count

; )

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

InternalMemCopyMem PROC USES rsi rdi

mov rsi, rdx ; rsi <- Source

mov rdi, rcx ; rdi <- Destination

lea r9, [rsi + r8 - 1] ; r9 <- End of Source

cmp rsi, rdi

mov rax, rdi ; rax <- Destination as return value

jae @F

cmp r9, rdi

jae @CopyBackward ; Copy backward if overlapped

@@:

mov rcx, r8

and r8, 7

shr rcx, 3

rep movsq ; Copy as many Qwords as possible

jmp @CopyBytes

@CopyBackward:

mov rsi, r9 ; rsi <- End of Source

lea rdi, [rdi + r8 - 1] ; esi <- End of Destination

std ; set direction flag

@CopyBytes:

mov rcx, r8

rep movsb ; Copy bytes backward

cld

ret

InternalMemCopyMem ENDP

END