MdePkg/Library/BaseMemoryLibSse2/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), %edx              # edx <- Count
  41     movl    8(%esp), %edi               # edi <- Buffer
  42     movb    16(%esp), %al               # al <- Value
  43     xorl    %ecx, %ecx
  44     subl    %edi, %ecx
  45     andl    $15, %ecx                   # ecx + edi aligns on 16-byte boundary
  46     jz      L0
  47     cmpl    %edx, %ecx
  48     cmova   %edx, %ecx
  49     subl    %ecx, %edx
  50     rep
  51     stosb
  52 L0:
  53     movl    %edx, %ecx
  54     andl    $15, %edx
  55     shrl    $4, %ecx                    # ecx <- # of DQwords to set
  56     jz      @SetBytes
  57     movb    %al, %ah                    # ax <- Value | (Value << 8)
  58     addl    $-16, %esp
  59     movdqu  %xmm0, (%esp)
  60     movd    %eax, %xmm0
  61     pshuflw $0, %xmm0, %xmm0
  62     movlhps %xmm0, %xmm0
  63 L1:
  64     movntdq %xmm0, (%edi)
  65     addl    $16, %edi
  66     loop   L1
  67     mfence
  68     movdqu  (%esp), %xmm0
  69     addl    $16, %esp                   # stack cleanup
  70 @SetBytes:
  71     movl    %edx, %ecx
  72     rep
  73     stosb
  74     movl    8(%esp), %eax               # eax <- Buffer as return value
  75     pop     %edi
  76     ret