MdePkg/Library/BaseMemoryLibMmx/Ia32/ZeroMem.s

   1 #------------------------------------------------------------------------------
   2 #
   3 # Copyright (c) 2006, Intel Corporation
   4 # All rights reserved. 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     .686:
  25     #.MODEL flat,C
  26     .xmm:
  27     .code:
  28
  29 #------------------------------------------------------------------------------
  30 #  VOID *
  31 #  _mem_ZeroMem (
  32 #    IN VOID   *Buffer,
  33 #    IN UINTN  Count
  34 #    )
  35 #------------------------------------------------------------------------------
  36 .global _InternalMemZeroMem
  37 _InternalMemZeroMem:
  38     push    %edi
  39     movl    8(%esp), %edi
  40     movl    12(%esp), %ecx
  41     movl    %ecx, %edx
  42     shrl    $3, %ecx
  43     jz      @ZeroBytes
  44     pxor    %mm0, %mm0
  45 L0:
  46     movntq  %mm0, (%edi)
  47     addl    $8, %edi
  48     loop    L0
  49     mfence
  50 @ZeroBytes:
  51     andl    $7, %edx
  52     xorl    %eax, %eax
  53     movl    %edx, %ecx
  54     rep
  55     stosb
  56     movl    8(%esp), %eax
  57     pop     %edi
  58     ret