1;------------------------------------------------------------------------------ 2; 3; Copyright (c) 2007, 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; EfiCopyMemRep4.asm 15; 16; Abstract: 17; 18; CopyMem function 19; 20; Notes: 21; 22;------------------------------------------------------------------------------ 23 24 .code 25 26;------------------------------------------------------------------------------ 27; VOID 28; EfiCommonLibCopyMem ( 29; OUT VOID *Destination, 30; IN VOID *Source, 31; IN UINTN Count 32; ); 33;------------------------------------------------------------------------------ 34EfiCommonLibCopyMem PROC USES rsi rdi 35 cmp rdx, rcx ; if Source == Destination, do nothing 36 je @CopyMemDone 37 cmp r8, 0 ; if Count == 0, do nothing 38 je @CopyMemDone 39 mov rsi, rdx ; rsi <- Source 40 mov rdi, rcx ; rdi <- Destination 41 lea r9, [rsi + r8 - 1] ; r9 <- End of Source 42 cmp rsi, rdi 43 jae @F 44 cmp r9, rdi 45 jae @CopyBackward ; Copy backward if overlapped 46@@: 47 mov rcx, r8 48 and r8, 3 49 shr rcx, 2 50 rep movsd ; Copy as many Dwords as possible 51 jmp @CopyBytes 52@CopyBackward: 53 mov rsi, r9 ; rsi <- End of Source 54 lea rdi, [rdi + r8 - 1] ; esi <- End of Destination 55 std ; set direction flag 56@CopyBytes: 57 mov rcx, r8 58 rep movsb ; Copy bytes backward 59 cld 60@CopyMemDone: 61 ret 62EfiCommonLibCopyMem ENDP 63 64 END 65 66