MdePkg/Library/BaseMemoryLibMmx/X64/ZeroMem.nasm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>
   4 ; SPDX-License-Identifier: BSD-2-Clause-Patent
   5 ;
   6 ; Module Name:
   7 ;
   8 ;   ZeroMem.nasm
   9 ;
  10 ; Abstract:
  11 ;
  12 ;   ZeroMem function
  13 ;
  14 ; Notes:
  15 ;
  16 ;------------------------------------------------------------------------------
  17
  18     DEFAULT REL
  19     SECTION .text
  20
  21 ;------------------------------------------------------------------------------
  22 ;  VOID *
  23 ;  InternalMemZeroMem (
  24 ;    IN VOID   *Buffer,
  25 ;    IN UINTN  Count
  26 ;    );
  27 ;------------------------------------------------------------------------------
  28 global ASM_PFX(InternalMemZeroMem)
  29 ASM_PFX(InternalMemZeroMem):
  30     push    rdi
  31     mov     rdi, rcx
  32     mov     rcx, rdx
  33     mov     r8, rdi
  34     and     edx, 7
  35     shr     rcx, 3
  36     jz      @ZeroBytes
  37     DB      0xf, 0xef, 0xc0             ; pxor mm0, mm0
  38 .0:
  39     DB      0xf, 0xe7, 7                ; movntq [rdi], mm0
  40     add     rdi, 8
  41     loop    .0
  42     DB      0xf, 0xae, 0xf0             ; mfence
  43 @ZeroBytes:
  44     xor     eax, eax
  45     mov     ecx, edx
  46     rep     stosb
  47     mov     rax, r8
  48     pop     rdi
  49     ret
  50