|
Last change
on this file since 80924 was 80721, checked in by vboxsync, 6 years ago |
|
Devices/EFI/FirmwareNew: Start upgrade process to edk2-stable201908 (compiles on Windows and works to some extent), bugref:4643
|
-
Property svn:eol-style
set to
native
|
|
File size:
907 bytes
|
| Line | |
|---|
| 1 | /** @file
|
|---|
| 2 | Math worker functions.
|
|---|
| 3 |
|
|---|
| 4 | Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
|
|---|
| 5 | SPDX-License-Identifier: BSD-2-Clause-Patent
|
|---|
| 6 |
|
|---|
| 7 | **/
|
|---|
| 8 |
|
|---|
| 9 |
|
|---|
| 10 |
|
|---|
| 11 |
|
|---|
| 12 | #include "BaseLibInternals.h"
|
|---|
| 13 |
|
|---|
| 14 | /**
|
|---|
| 15 | Returns the bit position of the lowest bit set in a 64-bit value.
|
|---|
| 16 |
|
|---|
| 17 | This function computes the bit position of the lowest bit set in the 64-bit
|
|---|
| 18 | value specified by Operand. If Operand is zero, then -1 is returned.
|
|---|
| 19 | Otherwise, a value between 0 and 63 is returned.
|
|---|
| 20 |
|
|---|
| 21 | @param Operand The 64-bit operand to evaluate.
|
|---|
| 22 |
|
|---|
| 23 | @retval 0..63 The lowest bit set in Operand was found.
|
|---|
| 24 | @retval -1 Operand is zero.
|
|---|
| 25 |
|
|---|
| 26 |
|
|---|
| 27 | **/
|
|---|
| 28 | INTN
|
|---|
| 29 | EFIAPI
|
|---|
| 30 | LowBitSet64 (
|
|---|
| 31 | IN UINT64 Operand
|
|---|
| 32 | )
|
|---|
| 33 | {
|
|---|
| 34 | INTN BitIndex;
|
|---|
| 35 |
|
|---|
| 36 | if (Operand == 0) {
|
|---|
| 37 | return -1;
|
|---|
| 38 | }
|
|---|
| 39 |
|
|---|
| 40 | for (BitIndex = 0;
|
|---|
| 41 | (Operand & 1) == 0;
|
|---|
| 42 | BitIndex++, Operand = RShiftU64 (Operand, 1));
|
|---|
| 43 | return BitIndex;
|
|---|
| 44 | }
|
|---|
Note:
See
TracBrowser
for help on using the repository browser.
