1 ;------------------------------------------------------------------------------
3 ; Copyright (c) 2007, Intel Corporation
4 ; All rights reserved. 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
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.
22 ;------------------------------------------------------------------------------
26 ;------------------------------------------------------------------------------
29 ; OUT VOID *DestinationBuffer,
30 ; IN CONST VOID *SourceBuffer,
33 ;------------------------------------------------------------------------------
34 memcpy PROC USES rsi rdi
35 mov rax, rcx ; rax <- Destination as return value
36 cmp rdx, rcx ; if Source == Destination, do nothing
38 cmp r8, 0 ; if Count == 0, do nothing
40 mov rsi, rdx ; rsi <- Source
41 mov rdi, rcx ; rdi <- Destination
42 lea r9, [rsi + r8 - 1] ; r9 <- End of Source
46 jae @CopyBackward ; Copy backward if overlapped
50 shr rcx, 3 ; rcx <- # of Qwords to copy
52 DB 49h, 0fh, 7eh, 0c2h ; movd r10, mm0 (Save mm0 in r10)
54 DB 0fh, 6fh, 06h ; movd mm0, [rsi]
55 DB 48h, 0fh, 7eh, 07h ; movd [rdi], mm0
59 DB 49h, 0fh, 6eh, 0c2h ; movd mm0, r10 (Restore mm0)
62 mov rsi, r9 ; rsi <- End of Source
63 lea rdi, [rdi + r8 - 1] ; rdi <- End of Destination
64 std ; set direction flag
67 rep movsb ; Copy bytes backward