mirror of https://github.com/acidanthera/audk.git
42 lines
1.2 KiB
C
42 lines
1.2 KiB
C
/** @file
|
|
Math worker functions.
|
|
|
|
Copyright (c) 2006, Intel Corporation<BR>
|
|
All rights reserved. This program and the accompanying materials
|
|
are licensed and made available under the terms and conditions of the BSD License
|
|
which accompanies this distribution. The full text of the license may be found at
|
|
http://opensource.org/licenses/bsd-license.php
|
|
|
|
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
|
|
|
|
**/
|
|
|
|
#include "BaseLibInternals.h"
|
|
|
|
/**
|
|
Returns the bit position of the highest bit set in a 32-bit value. Equivalent
|
|
to log2(x).
|
|
|
|
This function computes the bit position of the highest bit set in the 32-bit
|
|
value specified by Operand. If Operand is zero, then -1 is returned.
|
|
Otherwise, a value between 0 and 31 is returned.
|
|
|
|
@param Operand The 32-bit operand to evaluate.
|
|
|
|
@return Position of the highest bit set in Operand if found.
|
|
@retval -1 Operand is zero.
|
|
|
|
**/
|
|
INTN
|
|
EFIAPI
|
|
HighBitSet32 (
|
|
IN UINT32 Operand
|
|
)
|
|
{
|
|
INTN BitIndex;
|
|
|
|
for (BitIndex = -1; Operand != 0; BitIndex++, Operand >>= 1);
|
|
return BitIndex;
|
|
}
|