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.c 15 16 Abstract: 17 18 This is the code that uses rep movsd CopyMem service 19 20 --*/ 21 22 #include "Tiano.h" 23 24 VOID 25 EfiCommonLibCopyMem ( 26 IN VOID *Destination, 27 IN VOID *Source, 28 IN UINTN Count 29 ) 30 /*++ 31 32 Routine Description: 33 34 Copy Length bytes from Source to Destination. 35 36 Arguments: 37 38 Destination - Target of copy 39 40 Source - Place to copy from 41 42 Length - Number of bytes to copy 43 44 Returns: 45 46 None 47 48 --*/ 49 { 50 __asm { 51 mov esi, Source ; esi <- Source 52 mov edi, Destination ; edi <- Destination 53 mov edx, Count ; edx <- Count 54 cmp esi, edi 55 je _CopyDone 56 cmp edx, 0 57 je _CopyDone 58 lea eax, [esi + edx - 1] ; eax <- End of Source 59 cmp esi, edi 60 jae _CopyDWord 61 cmp eax, edi 62 jae _CopyBackward ; Copy backward if overlapped 63 _CopyDWord: 64 mov ecx, edx 65 and edx, 3 66 shr ecx, 2 67 rep movsd ; Copy as many Dwords as possible 68 jmp _CopyBytes 69 _CopyBackward: 70 mov esi, eax ; esi <- End of Source 71 lea edi, [edi + edx - 1] ; edi <- End of Destination 72 std 73 _CopyBytes: 74 mov ecx, edx 75 rep movsb ; Copy bytes backward 76 cld 77 _CopyDone: 78 } 79 } 80
