audk/MdePkg/Library/BaseMemoryLibMmx/X64/ZeroMem.nasm

51 lines
1.2 KiB
NASM

;------------------------------------------------------------------------------
;
; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>
; SPDX-License-Identifier: BSD-2-Clause-Patent
;
; Module Name:
;
; ZeroMem.nasm
;
; Abstract:
;
; ZeroMem function
;
; Notes:
;
;------------------------------------------------------------------------------
DEFAULT REL
SECTION .text
;------------------------------------------------------------------------------
; VOID *
; InternalMemZeroMem (
; IN VOID *Buffer,
; IN UINTN Count
; );
;------------------------------------------------------------------------------
global ASM_PFX(InternalMemZeroMem)
ASM_PFX(InternalMemZeroMem):
push rdi
mov rdi, rcx
mov rcx, rdx
mov r8, rdi
and edx, 7
shr rcx, 3
jz @ZeroBytes
DB 0xf, 0xef, 0xc0 ; pxor mm0, mm0
.0:
DB 0xf, 0xe7, 7 ; movntq [rdi], mm0
add rdi, 8
loop .0
DB 0xf, 0xae, 0xf0 ; mfence
@ZeroBytes:
xor eax, eax
mov ecx, edx
rep stosb
mov rax, r8
pop rdi
ret