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/*++
Copyright (c) 2004 - 2006, Intel Corporation
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.
Module Name:
LowBitSet64.c
Abstract:
Math worker functions.
--*/
#include "BaseLibInternal.h"
/**
Returns the bit position of the lowest bit set in a 64-bit value.
This function computes the bit position of the lowest 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.
@return Position of the lowest bit set in Operand if found.
@retval -1 Operand is zero.
**/
INTN
EFIAPI
LowBitSet64 (
IN UINT64 Operand
)
{
INTN BitIndex;
if (Operand == 0) {
return -1;
}
for (BitIndex = 0;
(Operand & 1) == 0;
BitIndex++, Operand = RShiftU64 (Operand, 1));
return BitIndex;
}
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