mirror of
https://github.com/CloverHackyColor/CloverBootloader.git
synced 2024-11-30 12:43:41 +01:00
50 lines
1.1 KiB
C
50 lines
1.1 KiB
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 64-bit value. Equivalent
|
|
to log2(x).
|
|
|
|
This function computes the bit position of the highest bit set in the 64-bit
|
|
value specified by Operand. If Operand is zero, then -1 is returned.
|
|
Otherwise, a value between 0 and 63 is returned.
|
|
|
|
@param Operand The 64-bit operand to evaluate.
|
|
|
|
@retval 0..63 Position of the highest bit set in Operand if found.
|
|
@retval -1 Operand is zero.
|
|
|
|
**/
|
|
INTN
|
|
EFIAPI
|
|
HighBitSet64 (
|
|
IN UINT64 Operand
|
|
)
|
|
{
|
|
if (Operand == (UINT32)Operand) {
|
|
//
|
|
// Operand is just a 32-bit integer
|
|
//
|
|
return HighBitSet32 ((UINT32)Operand);
|
|
}
|
|
|
|
//
|
|
// Operand is really a 64-bit integer
|
|
//
|
|
if (sizeof (UINTN) == sizeof (UINT32)) {
|
|
return HighBitSet32 (((UINT32*)&Operand)[1]) + 32;
|
|
} else {
|
|
return HighBitSet32 ((UINT32)RShiftU64 (Operand, 32)) + 32;
|
|
}
|
|
}
|