MdePkg/Library/BaseLib/SwapBytes32.c

   1 /** @file
   2   Math worker functions.
   3
   4   Copyright (c) 2006, 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 #include "BaseLibInternals.h"
  19
  20 /**
  21   Switches the endianess of a 32-bit integer.
  22
  23   This function swaps the bytes in a 32-bit unsigned value to switch the value
  24   from little endian to big endian or vice versa. The byte swapped value is
  25   returned.
  26
  27   @param  Operand A 32-bit unsigned value.
  28
  29   @return The byte swaped Operand.
  30
  31 **/
  32 UINT32
  33 EFIAPI
  34 SwapBytes32 (
  35   IN      UINT32                    Operand
  36   )
  37 {
  38   UINT32  LowerBytes;
  39   UINT32  HigherBytes;
  40
  41   LowerBytes  = (UINT32) SwapBytes16 ((UINT16) Operand);
  42   HigherBytes = (UINT32) SwapBytes16 ((UINT16) (Operand >> 16));
  43
  44   return (LowerBytes << 16 | HigherBytes);
  45 }