MdePkg/Library/BaseMemoryLibMmx/X64/SetMem.nasm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>
   4 ; SPDX-License-Identifier: BSD-2-Clause-Patent
   5 ;
   6 ; Module Name:
   7 ;
   8 ;   SetMem.nasm
   9 ;
  10 ; Abstract:
  11 ;
  12 ;   SetMem function
  13 ;
  14 ; Notes:
  15 ;
  16 ;------------------------------------------------------------------------------
  17
  18     DEFAULT REL
  19     SECTION .text
  20
  21 ;------------------------------------------------------------------------------
  22 ; VOID *
  23 ; EFIAPI
  24 ; InternalMemSetMem (
  25 ;   OUT     VOID                      *Buffer,
  26 ;   IN      UINTN                     Length,
  27 ;   IN      UINT8                     Value
  28 ;   );
  29 ;------------------------------------------------------------------------------
  30 global ASM_PFX(InternalMemSetMem)
  31 ASM_PFX(InternalMemSetMem):
  32     push    rdi
  33     mov     rax, r8
  34     mov     ah, al
  35     DB      0x48, 0xf, 0x6e, 0xc0         ; movd mm0, rax
  36     mov     r8, rcx
  37     mov     rdi, r8                     ; rdi <- Buffer
  38     mov     rcx, rdx
  39     and     edx, 7
  40     shr     rcx, 3
  41     jz      @SetBytes
  42     DB      0xf, 0x70, 0xC0, 0x0         ; pshufw mm0, mm0, 0h
  43 .0:
  44     DB      0xf, 0xe7, 0x7              ; movntq [rdi], mm0
  45     add     rdi, 8
  46     loop    .0
  47     mfence
  48 @SetBytes:
  49     mov     ecx, edx
  50     rep     stosb
  51     mov     rax, r8
  52     pop     rdi
  53     ret
  54