MdePkg/Library/BaseLib/Ia32/ReadMm7.c

   1 /** @file
   2   AsmReadMm7 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 // Include common header file for this module.
  17 //
  18
  19
  20 /**
  21   Reads the current value of 64-bit MMX Register #7 (MM7).
  22
  23   Reads and returns the current value of MM7. This function is only available
  24   on IA-32 and X64.
  25
  26   @return The current value of MM7.
  27
  28 **/
  29 UINT64
  30 EFIAPI
  31 AsmReadMm7 (
  32   VOID
  33   )
  34 {
  35   _asm {
  36     push    eax
  37     push    eax
  38     movq    [esp], mm7
  39     pop     eax
  40     pop     edx
  41     emms
  42   }
  43 }
  44