1 /** @file
2   Implementation of 64-bit swap bytes
3 
4   Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
5   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   Switches the endianess of a 64-bit integer.
20 
21   This function swaps the bytes in a 64-bit unsigned value to switch the value
22   from little endian to big endian or vice versa. The byte swapped value is
23   returned.
24 
25   @param  Operand A 64-bit unsigned value.
26 
27   @return The byte swaped Operand.
28 
29 **/
30 UINT64
31 EFIAPI
InternalMathSwapBytes64(IN UINT64 Operand)32 InternalMathSwapBytes64 (
33   IN      UINT64                    Operand
34   )
35 {
36   _asm {
37     mov     eax, dword ptr [Operand + 4]
38     mov     edx, dword ptr [Operand + 0]
39     bswap   eax
40     bswap   edx
41   }
42 }
43 
44