MdePkg/Library/BaseLib/Ia32/ReadMm3.c

   1 /** @file
   2   AsmReadMm3 function
   3
   4   Copyright (c) 2006 - 2007, Intel Corporation<BR>
   5   All rights reserved. This program and the accompanying materials
   6   are licensed and made available under the terms and conditions of the BSD License
   7   which accompanies this distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15
  16
  17
  18 /**
  19   Reads the current value of 64-bit MMX Register #3 (MM3).
  20
  21   Reads and returns the current value of MM3. This function is only available
  22   on IA-32 and X64.
  23
  24   @return The current value of MM3.
  25
  26 **/
  27 UINT64
  28 EFIAPI
  29 AsmReadMm3 (
  30   VOID
  31   )
  32 {
  33   _asm {
  34     push    eax
  35     push    eax
  36     movq    [esp], mm3
  37     pop     eax
  38     pop     edx
  39     emms
  40   }
  41 }
  42