MdePkg/Library/BaseMemoryLibMmx/ia32/SetMem.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 #   SetMem.asm
  15 #
  16 # Abstract:
  17 #
  18 #   SetMem function
  19 #
  20 # Notes:
  21 #
  22 #------------------------------------------------------------------------------
  23
  24     .686:
  25     #.MODEL flat,C
  26     .xmm:
  27     .code:
  28
  29 #------------------------------------------------------------------------------
  30 #  VOID *
  31 #  _mem_SetMem (
  32 #    IN VOID   *Buffer,
  33 #    IN UINTN  Count,
  34 #    IN UINT8  Value
  35 #    )
  36 #------------------------------------------------------------------------------
  37 .global _InternalMemSetMem
  38 _InternalMemSetMem:
  39     push    %edi
  40     movl    12(%esp), %ecx              # ecx <- Count
  41     movl    8(%esp), %edi               # edi <- Buffer
  42     movl    %ecx, %edx
  43     shrl    $3, %ecx                    # # of Qwords to set
  44     movb    16(%esp), %al               # al <- Value
  45     jz      @SetBytes
  46     movb    %al, %ah                    # ax <- Value | (Value << 8)
  47     pushl   %ecx
  48     pushl   %ecx
  49     movq    %mm0, (%esp)                # save mm0
  50     movd    %eax, %mm0
  51     pshufw  $0x0,%mm0,%mm0
  52 L0:
  53     movntq  %mm0, (%edi)
  54     addl    $8, %edi
  55     loop    L0
  56     mfence
  57     movq    (%esp), %mm0                # restore mm0
  58     popl    %ecx                        # stack cleanup
  59     popl    %ecx
  60 @SetBytes:
  61     andl    $7, %edx
  62     movl    %edx, %ecx
  63     rep
  64     stosb
  65     movl    8(%esp), %eax               # eax <- Buffer as return value
  66     pop     %edi
  67     ret