MdePkg/Library/BaseMemoryLibSse2/X64/ZeroMem.asm

   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.asm
  15 ;
  16 ; Abstract:
  17 ;
  18 ;   ZeroMem function
  19 ;
  20 ; Notes:
  21 ;
  22 ;------------------------------------------------------------------------------
  23
  24     .code
  25
  26 ;------------------------------------------------------------------------------
  27 ;  VOID *
  28 ;  InternalMemZeroMem (
  29 ;    IN VOID   *Buffer,
  30 ;    IN UINTN  Count
  31 ;    )
  32 ;------------------------------------------------------------------------------
  33 InternalMemZeroMem  PROC    USES    rdi
  34     mov     rdi, rcx
  35     xor     rcx, rcx
  36     xor     eax, eax
  37     sub     rcx, rdi
  38     and     rcx, 15
  39     mov     r8, rdi
  40     jz      @F
  41     cmp     rcx, rdx
  42     cmova   rcx, rdx
  43     sub     rdx, rcx
  44     rep     stosb
  45 @@:
  46     mov     rcx, rdx
  47     and     edx, 15
  48     shr     rcx, 4
  49     jz      @ZeroBytes
  50     pxor    xmm0, xmm0
  51 @@:
  52     movntdq [rdi], xmm0                 ; rdi should be 16-byte aligned
  53     add     rdi, 16
  54     loop    @B
  55     mfence
  56 @ZeroBytes:
  57     mov     ecx, edx
  58     rep     stosb
  59     mov     rax, r8
  60     ret
  61 InternalMemZeroMem  ENDP
  62
  63     END