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 <- Last byte of Source 39 cmp rsi, rdi 40 mov rax, rdi ; rax <- Destination as return value 41 jae @F ; Copy forward if Source > Destination 42 cmp r9, rdi ; Overlapped? 43 jae @CopyBackward ; Copy backward if overlapped 44 @@: 45 xor rcx, rcx 46 sub rcx, rdi ; rcx <- -rdi 47 and rcx, 15 ; rcx + rsi should be 16 bytes aligned 48 jz @F ; skip if rcx == 0 49 cmp rcx, r8 50 cmova rcx, r8 51 sub r8, rcx 52 rep movsb 53 @@: 54 mov rcx, r8 55 and r8, 15 56 shr rcx, 4 ; rcx <- # of DQwords to copy 57 jz @CopyBytes 58 movdqa [rsp + 18h], xmm0 ; save xmm0 on stack 59 @@: 60 movdqu xmm0, [rsi] ; rsi may not be 16-byte aligned 61 movntdq [rdi], xmm0 ; rdi should be 16-byte aligned 62 add rsi, 16 63 add rdi, 16 64 loop @B 65 mfence 66 movdqa xmm0, [rsp + 18h] ; restore xmm0 67 jmp @CopyBytes ; copy remaining bytes 68 @CopyBackward: 69 mov rsi, r9 ; rsi <- Last byte of Source 70 lea rdi, [rdi + r8 - 1] ; rdi <- Last byte of Destination 71 std 72 @CopyBytes: 73 mov rcx, r8 74 rep movsb 75 cld 76 ret 77 InternalMemCopyMem ENDP 78 79 END 80
