mirror of
https://github.com/CloverHackyColor/CloverBootloader.git
synced 2024-12-18 15:27:48 +01:00
42 lines
955 B
C
42 lines
955 B
C
/** @file
|
|
Math worker functions.
|
|
|
|
Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
|
|
SPDX-License-Identifier: BSD-2-Clause-Patent
|
|
|
|
**/
|
|
|
|
|
|
|
|
|
|
#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.
|
|
|
|
@retval 0..31 Position of the highest bit set in Operand if found.
|
|
@retval -1 Operand is zero.
|
|
|
|
**/
|
|
INTN
|
|
EFIAPI
|
|
HighBitSet32 (
|
|
IN UINT32 Operand
|
|
)
|
|
{
|
|
INTN BitIndex;
|
|
|
|
if (Operand == 0) {
|
|
return - 1;
|
|
}
|
|
for (BitIndex = 31; (INT32)Operand > 0; BitIndex--, Operand <<= 1);
|
|
return BitIndex;
|
|
}
|