| vanjeff | e1f414b | 2007-06-22 03:21:45 +0000 | [diff] [blame] | 1 | /** @file
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| 2 | Math worker functions.
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| 3 |
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| qhuang8 | 373ade0 | 2008-12-29 14:07:07 +0000 | [diff] [blame] | 4 | Copyright (c) 2006 - 2008, Intel Corporation<BR>
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| vanjeff | e1f414b | 2007-06-22 03:21:45 +0000 | [diff] [blame] | 5 | All rights reserved. This program and the accompanying materials
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| 6 | are licensed and made available under the terms and conditions of the BSD License
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| 7 | which accompanies this distribution. The full text of the license may be found at
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| 8 | http://opensource.org/licenses/bsd-license.php
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| 9 |
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| 10 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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| 11 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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| 12 |
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| 13 | **/
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| 14 |
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| vanjeff | 1efcc4a | 2008-09-17 07:46:17 +0000 | [diff] [blame] | 15 |
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| AJFISH | f734a10 | 2007-06-29 23:22:13 +0000 | [diff] [blame] | 16 |
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| vanjeff | e1f414b | 2007-06-22 03:21:45 +0000 | [diff] [blame] | 17 |
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| 18 | #include "BaseLibInternals.h"
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| 19 |
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| 20 | /**
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| 21 | Returns the value of the highest bit set in a 64-bit value. Equivalent to
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| gikidy | 9aa049d | 2008-11-25 03:19:49 +0000 | [diff] [blame] | 22 | 1 << log2(x).
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| vanjeff | e1f414b | 2007-06-22 03:21:45 +0000 | [diff] [blame] | 23 |
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| 24 | This function computes the value of the highest bit set in the 64-bit value
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| 25 | specified by Operand. If Operand is zero, then zero is returned.
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| 26 |
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| 27 | @param Operand The 64-bit operand to evaluate.
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| 28 |
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| 29 | @return 1 << HighBitSet64(Operand)
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| 30 | @retval 0 Operand is zero.
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| 31 |
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| 32 | **/
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| 33 | UINT64
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| 34 | EFIAPI
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| 35 | GetPowerOfTwo64 (
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| 36 | IN UINT64 Operand
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| 37 | )
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| 38 | {
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| 39 | if (Operand == 0) {
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| 40 | return 0;
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| 41 | }
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| 42 |
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| 43 | return LShiftU64 (1, HighBitSet64 (Operand));
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| 44 | }
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