mirror of
https://github.com/aaru-dps/Aaru.git
synced 2025-12-16 11:14:25 +00:00
48 lines
1.9 KiB
C#
48 lines
1.9 KiB
C#
// /***************************************************************************
|
|
// Aaru Data Preservation Suite
|
|
// ----------------------------------------------------------------------------
|
|
//
|
|
// Filename : CountBits.cs
|
|
// Author(s) : Natalia Portillo <claunia@claunia.com>
|
|
//
|
|
// Component : Helpers.
|
|
//
|
|
// --[ Description ] ----------------------------------------------------------
|
|
//
|
|
// Counts bits in a number.
|
|
//
|
|
// --[ License ] --------------------------------------------------------------
|
|
//
|
|
// This library is free software; you can redistribute it and/or modify
|
|
// it under the terms of the GNU Lesser General Public License as
|
|
// published by the Free Software Foundation; either version 2.1 of the
|
|
// License, or (at your option) any later version.
|
|
//
|
|
// This library is distributed in the hope that it will be useful, but
|
|
// WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
// Lesser General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Lesser General Public
|
|
// License along with this library; if not, see <http://www.gnu.org/licenses/>.
|
|
//
|
|
// ----------------------------------------------------------------------------
|
|
// Copyright © 2011-2025 Natalia Portillo
|
|
// ****************************************************************************/
|
|
|
|
namespace Aaru.Helpers;
|
|
|
|
/// <summary>Helper operations to count bits</summary>
|
|
public static class CountBits
|
|
{
|
|
/// <summary>Counts the number of bits set to <c>true</c> in a number</summary>
|
|
/// <param name="number">Number</param>
|
|
/// <returns>Bits set to <c>true</c></returns>
|
|
public static int Count(uint number)
|
|
{
|
|
number -= number >> 1 & 0x55555555;
|
|
number = (number & 0x33333333) + (number >> 2 & 0x33333333);
|
|
|
|
return (int)((number + (number >> 4) & 0x0F0F0F0F) * 0x01010101 >> 24);
|
|
}
|
|
} |