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      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 ;   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 ;  EFIAPI
     32 ;  InternalMemSetMem (
     33 ;    IN VOID   *Buffer,
     34 ;    IN UINTN  Count,
     35 ;    IN UINT8  Value
     36 ;    );
     37 ;------------------------------------------------------------------------------
     38 InternalMemSetMem   PROC    USES    edi
     39     mov     edx, [esp + 12]             ; edx <- Count
     40     mov     edi, [esp + 8]              ; edi <- Buffer
     41     mov     al, [esp + 16]              ; al <- Value
     42     xor     ecx, ecx
     43     sub     ecx, edi
     44     and     ecx, 15                     ; ecx + edi aligns on 16-byte boundary
     45     jz      @F
     46     cmp     ecx, edx
     47     cmova   ecx, edx
     48     sub     edx, ecx
     49     rep     stosb
     50 @@:
     51     mov     ecx, edx
     52     and     edx, 15
     53     shr     ecx, 4                      ; ecx <- # of DQwords to set
     54     jz      @SetBytes
     55     mov     ah, al                      ; ax <- Value | (Value << 8)
     56     add     esp, -16
     57     movdqu  [esp], xmm0                 ; save xmm0
     58     movd    xmm0, eax
     59     pshuflw xmm0, xmm0, 0               ; xmm0[0..63] <- Value repeats 8 times
     60     movlhps xmm0, xmm0                  ; xmm0 <- Value repeats 16 times
     61 @@:
     62     movntdq [edi], xmm0                 ; edi should be 16-byte aligned
     63     add     edi, 16
     64     loop    @B
     65     mfence
     66     movdqu  xmm0, [esp]                 ; restore xmm0
     67     add     esp, 16                     ; stack cleanup
     68 @SetBytes:
     69     mov     ecx, edx
     70     rep     stosb
     71     mov     eax, [esp + 8]              ; eax <- Buffer as return value
     72     ret
     73 InternalMemSetMem   ENDP
     74 
     75     END
     76