MdePkg/Library/BaseMemoryLibMmx/ia32/SetMem.asm

   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 InternalMemSetMem   PROC    USES    edi
  38     mov     ecx, [esp + 12]             ; ecx <- Count
  39     mov     edi, [esp + 8]              ; edi <- Buffer
  40     mov     edx, ecx
  41     shr     ecx, 3                      ; # of Qwords to set
  42     mov     al, [esp + 16]              ; al <- Value
  43     jz      @SetBytes
  44     mov     ah, al                      ; ax <- Value | (Value << 8)
  45     push    ecx
  46     push    ecx
  47     movq    [esp], mm0                  ; save mm0
  48     movd    mm0, eax
  49     pshufw  mm0, mm0, 0                 ; fill mm0 with 8 Value's
  50 @@:
  51     movntq  [edi], mm0
  52     add     edi, 8
  53     loop    @B
  54     mfence
  55     movq    mm0, [esp]                  ; restore mm0
  56     pop     ecx                         ; stack cleanup
  57     pop     ecx
  58 @SetBytes:
  59     and     edx, 7
  60     mov     ecx, edx
  61     rep     stosb
  62     mov     eax, [esp + 8]              ; eax <- Buffer as return value
  63     ret
  64 InternalMemSetMem   ENDP
  65
  66     END