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;------------------------------------------------------------------------------
;
; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>
; SPDX-License-Identifier: BSD-2-Clause-Patent
;
; Module Name:
;
; SetMem.nasm
;
; Abstract:
;
; SetMem function
;
; Notes:
;
;------------------------------------------------------------------------------
DEFAULT REL
SECTION .text
;------------------------------------------------------------------------------
; VOID *
; InternalMemSetMem (
; IN VOID *Buffer,
; IN UINTN Count,
; IN UINT8 Value
; )
;------------------------------------------------------------------------------
global ASM_PFX(InternalMemSetMem)
ASM_PFX(InternalMemSetMem):
push rdi
mov rdi, rcx ; rdi <- Buffer
mov al, r8b ; al <- Value
mov r9, rdi ; r9 <- Buffer as return value
xor rcx, rcx
sub rcx, rdi
and rcx, 15 ; rcx + rdi aligns on 16-byte boundary
jz .0
cmp rcx, rdx
cmova rcx, rdx
sub rdx, rcx
rep stosb
.0:
mov rcx, rdx
and rdx, 15
shr rcx, 4
jz @SetBytes
mov ah, al ; ax <- Value repeats twice
movdqa [rsp + 0x10], xmm0 ; save xmm0
movd xmm0, eax ; xmm0[0..16] <- Value repeats twice
pshuflw xmm0, xmm0, 0 ; xmm0[0..63] <- Value repeats 8 times
movlhps xmm0, xmm0 ; xmm0 <- Value repeats 16 times
.1:
movntdq [rdi], xmm0 ; rdi should be 16-byte aligned
add rdi, 16
loop .1
mfence
movdqa xmm0, [rsp + 0x10] ; restore xmm0
@SetBytes:
mov ecx, edx ; high 32 bits of rcx are always zero
rep stosb
mov rax, r9 ; rax <- Return value
pop rdi
ret
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