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 .code 25 26 ;------------------------------------------------------------------------------ 27 ; VOID * 28 ; memset ( 29 ; OUT VOID *Buffer, --> rcx 30 ; IN UINT8 Value, --> rdx 31 ; IN UINTN Length --> r8 32 ; ); 33 ;------------------------------------------------------------------------------ 34 memset PROC USES rdi 35 mov rax, rcx 36 cmp r8, 0 ; if Size == 0, do nothing 37 je @SetDone 38 mov rax, rdx ; rdx <-> r8 39 mov rdx, r8 ; rdx <- Length 40 mov r8, rax ; r8 <- Value 41 42 mov rdi, rcx ; rdi <- Buffer 43 mov al, r8b ; al <- Value 44 mov r9, rdi ; r9 <- Buffer as return value 45 xor rcx, rcx 46 sub rcx, rdi 47 and rcx, 15 ; rcx + rdi aligns on 16-byte boundary 48 jz @F 49 cmp rcx, rdx 50 cmova rcx, rdx 51 sub rdx, rcx 52 rep stosb 53 @@: 54 mov rcx, rdx 55 and rdx, 15 56 shr rcx, 4 57 jz @SetBytes 58 mov ah, al ; ax <- Value repeats twice 59 movd xmm0, eax ; xmm0[0..16] <- Value repeats twice 60 pshuflw xmm0, xmm0, 0 ; xmm0[0..63] <- Value repeats 8 times 61 movlhps xmm0, xmm0 ; xmm0 <- Value repeats 16 times 62 @@: 63 movdqa [rdi], xmm0 ; rdi should be 16-byte aligned 64 add rdi, 16 65 loop @B 66 @SetBytes: 67 mov ecx, edx ; high 32 bits of rcx are always zero 68 rep stosb 69 mov rax, r9 ; rax <- Return value 70 @SetDone: 71 ret 72 memset ENDP 73 74 END 75
