EdkCompatibilityPkg/Foundation/Library/CompilerStub/X64/memset.asm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; Copyright (c) 2007, 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 ;   memset function
  19 ;
  20 ; Notes:
  21 ;
  22 ;------------------------------------------------------------------------------
  23
  24     .code
  25
  26 ;------------------------------------------------------------------------------
  27 ; VOID *
  28 ; memset (
  29 ;   OUT     VOID                      *Buffer,    --> rcx
  30 ;   IN      UINT8                     Value,      --> rdx
  31 ;   IN      UINTN                     Length      --> r8
  32 ;   );
  33 ;------------------------------------------------------------------------------
  34 memset   PROC    USES    rdi
  35     mov     rax, rcx
  36     cmp     r8, 0                      ; if Size == 0, do nothing
  37     je      @SetDone
  38     mov     rax, rdx                   ; rdx <-> r8
  39     mov     rdx, r8                    ; rdx <- Length
  40     mov     r8, rax                    ; r8  <- Value
  41     mov     ah, al
  42     DB      48h, 0fh, 6eh, 0c0h         ; movd mm0, rax
  43     mov     r8, rcx
  44     mov     rdi, r8                     ; rdi <- Buffer
  45     mov     rcx, rdx
  46     and     edx, 7
  47     shr     rcx, 3
  48     jz      @SetBytes
  49     DB      0fh, 70h, 0C0h, 00h         ; pshufw mm0, mm0, 0h
  50 @@:
  51     DB      48h, 0fh, 7eh, 07h          ; movd [rdi], mm0
  52     add     rdi, 8
  53     loop    @B
  54 @SetBytes:
  55     mov     ecx, edx
  56     rep     stosb
  57     mov     rax, r8
  58 @SetDone:
  59     ret
  60 memset   ENDP
  61
  62     END