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 ; SetMem.asm 15 ; 16 ; Abstract: 17 ; 18 ; memset function 19 ; 20 ; Notes: 21 ; 22 ;------------------------------------------------------------------------------ 23 24 .686 25 .model flat,C 26 .xmm 27 .code 28 29 ;------------------------------------------------------------------------------ 30 ; VOID * 31 ; memset ( 32 ; OUT VOID *Buffer, 33 ; IN UINT8 Value, 34 ; IN UINTN Count 35 ; ) 36 ;------------------------------------------------------------------------------ 37 memset PROC USES edi 38 mov edx, [esp + 16] ; edx <- Count 39 cmp edx, 0 ; if Count == 0, do nothing 40 je @SetDone 41 mov edi, [esp + 8] ; edi <- Buffer 42 mov al, [esp + 12] ; al <- Value 43 xor ecx, ecx 44 sub ecx, edi 45 and ecx, 15 ; ecx + edi aligns on 16-byte boundary 46 jz @F 47 cmp ecx, edx 48 cmova ecx, edx 49 sub edx, ecx 50 rep stosb 51 @@: 52 mov ecx, edx 53 and edx, 15 54 shr ecx, 4 ; ecx <- # of DQwords to set 55 jz @SetBytes 56 mov ah, al ; ax <- Value | (Value << 8) 57 add esp, -16 58 movd xmm0, eax 59 pshuflw xmm0, xmm0, 0 ; xmm0[0..63] <- Value repeats 8 times 60 movlhps xmm0, xmm0 ; xmm0 <- Value repeats 16 times 61 @@: 62 movdqa [edi], xmm0 ; edi should be 16-byte aligned 63 add edi, 16 64 loop @B 65 add esp, 16 ; stack cleanup 66 @SetBytes: 67 mov ecx, edx 68 rep stosb 69 @SetDone: 70 mov eax, [esp + 8] ; eax <- Buffer as return value 71 ret 72 memset ENDP 73 74 END 75
