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45 lines
951 B
C
45 lines
951 B
C
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/** @file
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Math worker functions.
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Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
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SPDX-License-Identifier: BSD-2-Clause-Patent
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**/
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#include "BaseLibInternals.h"
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/**
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Returns the bit position of the lowest bit set in a 64-bit value.
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This function computes the bit position of the lowest bit set in the 64-bit
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value specified by Operand. If Operand is zero, then -1 is returned.
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Otherwise, a value between 0 and 63 is returned.
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@param Operand The 64-bit operand to evaluate.
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@retval 0..63 The lowest bit set in Operand was found.
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@retval -1 Operand is zero.
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**/
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INTN
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EFIAPI
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LowBitSet64 (
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IN UINT64 Operand
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)
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{
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INTN BitIndex;
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if (Operand == 0) {
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return -1;
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}
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for (BitIndex = 0;
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(Operand & 1) == 0;
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BitIndex++, Operand = RShiftU64 (Operand, 1));
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return BitIndex;
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}
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