;------------------------------------------------------------------------------ ; ; 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: ; ; EfiCopyMemRep4.asm ; ; Abstract: ; ; CopyMem function ; ; Notes: ; ;------------------------------------------------------------------------------ .code ;------------------------------------------------------------------------------ ; VOID ; EfiCommonLibCopyMem ( ; OUT VOID *Destination, ; IN VOID *Source, ; IN UINTN Count ; ); ;------------------------------------------------------------------------------ EfiCommonLibCopyMem PROC USES rsi rdi cmp rdx, rcx ; if Source == Destination, do nothing je @CopyMemDone cmp r8, 0 ; if Count == 0, do nothing je @CopyMemDone mov rsi, rdx ; rsi <- Source mov rdi, rcx ; rdi <- Destination lea r9, [rsi + r8 - 1] ; r9 <- End of Source cmp rsi, rdi jae @F cmp r9, rdi jae @CopyBackward ; Copy backward if overlapped @@: mov rcx, r8 and r8, 3 shr rcx, 2 rep movsd ; Copy as many Dwords 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 @CopyMemDone: ret EfiCommonLibCopyMem ENDP END