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

;------------------------------------------------------------------------------
;
; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>
; SPDX-License-Identifier: BSD-2-Clause-Patent
;
; Module Name:
;
;   ZeroMem.Asm
;
; 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
    push    rcx
    xor     rax, rax
    mov     rdi, rcx
    mov     rcx, rdx
    shr     rcx, 3
    and     rdx, 7
    rep     stosq
    mov     ecx, edx
    rep     stosb
    pop     rax
    pop     rdi
    ret