MdePkg/Library/BaseMemoryLibMmx/X64/ZeroMem.nasm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>
   4 ; This program and the accompanying materials
   5 ; are licensed and made available under the terms and conditions of the BSD License
   6 ; which accompanies this distribution.  The full text of the license may be found at
   7 ; http://opensource.org/licenses/bsd-license.php.
   8 ;
   9 ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11 ;
  12 ; Module Name:
  13 ;
  14 ;   ZeroMem.nasm
  15 ;
  16 ; Abstract:
  17 ;
  18 ;   ZeroMem function
  19 ;
  20 ; Notes:
  21 ;
  22 ;------------------------------------------------------------------------------
  23
  24     DEFAULT REL
  25     SECTION .text
  26
  27 ;------------------------------------------------------------------------------
  28 ;  VOID *
  29 ;  InternalMemZeroMem (
  30 ;    IN VOID   *Buffer,
  31 ;    IN UINTN  Count
  32 ;    );
  33 ;------------------------------------------------------------------------------
  34 global ASM_PFX(InternalMemZeroMem)
  35 ASM_PFX(InternalMemZeroMem):
  36     push    rdi
  37     mov     rdi, rcx
  38     mov     rcx, rdx
  39     mov     r8, rdi
  40     and     edx, 7
  41     shr     rcx, 3
  42     jz      @ZeroBytes
  43     DB      0xf, 0xef, 0xc0             ; pxor mm0, mm0
  44 .0:
  45     DB      0xf, 0xe7, 7                ; movntq [rdi], mm0
  46     add     rdi, 8
  47     loop    .0
  48     DB      0xf, 0xae, 0xf0             ; mfence
  49 @ZeroBytes:
  50     xor     eax, eax
  51     mov     ecx, edx
  52     rep     stosb
  53     mov     rax, r8
  54     pop     rdi
  55     ret
  56