MdePkg/Library/BaseMemoryLibSse2/Ia32/ZeroMem.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:
;
;------------------------------------------------------------------------------

    SECTION .text

;------------------------------------------------------------------------------
;  VOID *
;  EFIAPI
;  InternalMemZeroMem (
;    IN VOID   *Buffer,
;    IN UINTN  Count
;    );
;------------------------------------------------------------------------------
global ASM_PFX(InternalMemZeroMem)
ASM_PFX(InternalMemZeroMem):
    push    edi
    mov     edi, [esp + 8]
    mov     edx, [esp + 12]
    xor     ecx, ecx
    sub     ecx, edi
    xor     eax, eax
    and     ecx, 63
    jz      .0
    cmp     ecx, edx
    cmova   ecx, edx
    sub     edx, ecx
    rep     stosb
.0:
    mov     ecx, edx
    and     edx, 63
    shr     ecx, 6
    jz      @ZeroBytes
    pxor    xmm0, xmm0
.1:
    movntdq [edi], xmm0
    movntdq [edi + 16], xmm0
    movntdq [edi + 32], xmm0
    movntdq [edi + 48], xmm0
    add     edi, 64
    loop    .1
    mfence
@ZeroBytes:
    mov     ecx, edx
    rep     stosb
    mov     eax, [esp + 8]
    pop     edi
    ret