1 /** @file 2 Math worker functions. 3 4 Copyright (c) 2006 - 2010, 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 #include "BaseLibInternals.h" 19 20 /** 21 Returns the value of the highest bit set in a 64-bit value. Equivalent to 22 1 << log2(x). 23 24 This function computes the value of the highest bit set in the 64-bit value 25 specified by Operand. If Operand is zero, then zero is returned. 26 27 @param Operand The 64-bit operand to evaluate. 28 29 @return 1 << HighBitSet64(Operand) 30 @retval 0 Operand is zero. 31 32 **/ 33 UINT64 34 EFIAPI 35 GetPowerOfTwo64 ( 36 IN UINT64 Operand 37 ) 38 { 39 if (Operand == 0) { 40 return 0; 41 } 42 43 return LShiftU64 (1, (UINTN) HighBitSet64 (Operand)); 44 } 45
