1. Fix one bug on EBC for GetPowerOfTwo64.c
[mirror_edk2.git] / MdePkg / Library / BaseLib / GetPowerOfTwo64.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 #include "BaseLibInternals.h"
16
17 /**
18 Returns the value of the highest bit set in a 64-bit value. Equivalent to
19 1 << HighBitSet64(x).
20
21 This function computes the value of the highest bit set in the 64-bit value
22 specified by Operand. If Operand is zero, then zero is returned.
23
24 @param Operand The 64-bit operand to evaluate.
25
26 @return 1 << HighBitSet64(Operand)
27 @retval 0 Operand is zero.
28
29 **/
30 UINT64
31 EFIAPI
32 GetPowerOfTwo64 (
33 IN UINT64 Operand
34 )
35 {
36 INTN BitPos;
37
38 BitPos = HighBitSet64 (Operand);
39 return BitPos >= 0 ? LShiftU64 (1, BitPos) : 0;
40 }