1 ;------------------------------------------------------------------------------ 2 ; 3 ; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR> 4 ; This program and the accompanying materials 5 ; are licensed and made available under the terms and conditions of the BSD License 6 ; which accompanies this distribution. The full text of the license may be found at 7 ; http://opensource.org/licenses/bsd-license.php. 8 ; 9 ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 10 ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 11 ; 12 ; Module Name: 13 ; 14 ; CopyMem.Asm 15 ; 16 ; Abstract: 17 ; 18 ; CopyMem function 19 ; 20 ; Notes: 21 ; 22 ;------------------------------------------------------------------------------ 23 24 .code 25 26 ;------------------------------------------------------------------------------ 27 ; VOID * 28 ; EFIAPI 29 ; InternalMemCopyMem ( 30 ; IN VOID *Destination, 31 ; IN VOID *Source, 32 ; IN UINTN Count 33 ; ) 34 ;------------------------------------------------------------------------------ 35 InternalMemCopyMem PROC USES rsi rdi 36 mov rsi, rdx ; rsi <- Source 37 mov rdi, rcx ; rdi <- Destination 38 lea r9, [rsi + r8 - 1] ; r9 <- End of Source 39 cmp rsi, rdi 40 mov rax, rdi ; rax <- Destination as return value 41 jae @F 42 cmp r9, rdi 43 jae @CopyBackward ; Copy backward if overlapped 44 @@: 45 mov rcx, r8 46 and r8, 7 47 shr rcx, 3 48 rep movsq ; Copy as many Qwords as possible 49 jmp @CopyBytes 50 @CopyBackward: 51 mov rsi, r9 ; rsi <- End of Source 52 lea rdi, [rdi + r8 - 1] ; esi <- End of Destination 53 std ; set direction flag 54 @CopyBytes: 55 mov rcx, r8 56 rep movsb ; Copy bytes backward 57 cld 58 ret 59 InternalMemCopyMem ENDP 60 61 END 62
