CloverBootloader/MdePkg/Library/BaseLib/LowBitSet32.c
2019-09-03 12:58:42 +03:00

42 lines
914 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 lowest bit set in a 32-bit value.
This function computes the bit position of the lowest 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 The lowest bit set in Operand was found.
@retval -1 Operand is zero.
**/
INTN
EFIAPI
LowBitSet32 (
IN UINT32 Operand
)
{
INTN BitIndex;
if (Operand == 0) {
return -1;
}
for (BitIndex = 0; 0 == (Operand & 1); BitIndex++, Operand >>= 1);
return BitIndex;
}