MdePkg/Library/BaseLib/RRotU32.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 // Include common header file for this module.
  17 //
  18 #include "CommonHeader.h"
  19
  20 #include "BaseLibInternals.h"
  21
  22 /**
  23   Rotates a 32-bit integer right between 0 and 31 bits, filling the high bits
  24   with the low bits that were rotated.
  25
  26   This function rotates the 32-bit value Operand to the right by Count bits.
  27   The high Count bits are fill with the low Count bits of Operand. The rotated
  28   value is returned.
  29
  30   If Count is greater than 31, then ASSERT().
  31
  32   @param  Operand The 32-bit operand to rotate right.
  33   @param  Count   The number of bits to rotate right.
  34
  35   @return Operand >>> Count
  36
  37 **/
  38 UINT32
  39 EFIAPI
  40 RRotU32 (
  41   IN      UINT32                    Operand,
  42   IN      UINTN                     Count
  43   )
  44 {
  45   ASSERT (Count < sizeof (Operand) * 8);
  46   return (Operand >> Count) | (Operand << (32 - Count));
  47 }