127 lines
4.5 KiB
C#
127 lines
4.5 KiB
C#
#region Apache License 2.0
|
|
/*
|
|
Nuclex .NET Framework
|
|
Copyright (C) 2002-2024 Markus Ewald / Nuclex Development Labs
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
See the License for the specific language governing permissions and
|
|
limitations under the License.
|
|
*/
|
|
#endregion // Apache License 2.0
|
|
|
|
using System;
|
|
|
|
namespace Nuclex.Support {
|
|
|
|
/// <summary>Helper methods for working with integer types</summary>
|
|
public static class IntegerHelper {
|
|
|
|
/// <summary>Returns the next highest power of 2 from the specified value</summary>
|
|
/// <param name="value">Value of which to return the next highest power of 2</param>
|
|
/// <returns>The next highest power of 2 to the value</returns>
|
|
public static long NextPowerOf2(this long value) {
|
|
return (long)NextPowerOf2((ulong)value);
|
|
}
|
|
|
|
/// <summary>Returns the next highest power of 2 from the specified value</summary>
|
|
/// <param name="value">Value of which to return the next highest power of 2</param>
|
|
/// <returns>The next highest power of 2 to the value</returns>
|
|
public static ulong NextPowerOf2(this ulong value) {
|
|
if (value == 0)
|
|
return 1;
|
|
|
|
--value;
|
|
value |= value >> 1;
|
|
value |= value >> 2;
|
|
value |= value >> 4;
|
|
value |= value >> 8;
|
|
value |= value >> 16;
|
|
value |= value >> 32;
|
|
++value;
|
|
|
|
return value;
|
|
}
|
|
|
|
/// <summary>Returns the next highest power of 2 from the specified value</summary>
|
|
/// <param name="value">Value of which to return the next highest power of 2</param>
|
|
/// <returns>The next highest power of 2 to the value</returns>
|
|
public static int NextPowerOf2(this int value) {
|
|
return (int)NextPowerOf2((uint)value);
|
|
}
|
|
|
|
/// <summary>Returns the next highest power of 2 from the specified value</summary>
|
|
/// <param name="value">Value of which to return the next highest power of 2</param>
|
|
/// <returns>The next highest power of 2 to the value</returns>
|
|
public static uint NextPowerOf2(this uint value) {
|
|
if (value == 0)
|
|
return 1;
|
|
|
|
--value;
|
|
value |= value >> 1;
|
|
value |= value >> 2;
|
|
value |= value >> 4;
|
|
value |= value >> 8;
|
|
value |= value >> 16;
|
|
++value;
|
|
|
|
return value;
|
|
}
|
|
|
|
/// <summary>Returns the number of bits set in an integer</summary>
|
|
/// <param name="value">Value whose bits will be counted</param>
|
|
/// <returns>The number of bits set in the integer</returns>
|
|
public static int CountBits(this int value) {
|
|
return CountBits((uint)value);
|
|
}
|
|
|
|
/// <summary>Returns the number of bits set in an unsigned integer</summary>
|
|
/// <param name="value">Value whose bits will be counted</param>
|
|
/// <returns>The number of bits set in the unsigned integer</returns>
|
|
/// <remarks>
|
|
/// Based on a trick revealed here:
|
|
/// http://stackoverflow.com/questions/109023
|
|
/// </remarks>
|
|
public static int CountBits(this uint value) {
|
|
value = value - ((value >> 1) & 0x55555555);
|
|
value = (value & 0x33333333) + ((value >> 2) & 0x33333333);
|
|
|
|
return (int)unchecked(
|
|
((value + (value >> 4) & 0xF0F0F0F) * 0x1010101) >> 24
|
|
);
|
|
}
|
|
|
|
/// <summary>Returns the number of bits set in a long integer</summary>
|
|
/// <param name="value">Value whose bits will be counted</param>
|
|
/// <returns>The number of bits set in the long integer</returns>
|
|
public static int CountBits(this long value) {
|
|
return CountBits((ulong)value);
|
|
}
|
|
|
|
/// <summary>Returns the number of bits set in an unsigned long integer</summary>
|
|
/// <param name="value">Value whose bits will be counted</param>
|
|
/// <returns>The number of bits set in the unsigned long integer</returns>
|
|
/// <remarks>
|
|
/// Based on a trick revealed here:
|
|
/// http://stackoverflow.com/questions/2709430
|
|
/// </remarks>
|
|
public static int CountBits(this ulong value) {
|
|
value = value - ((value >> 1) & 0x5555555555555555UL);
|
|
value = (value & 0x3333333333333333UL) + ((value >> 2) & 0x3333333333333333UL);
|
|
|
|
return (int)unchecked(
|
|
(((value + (value >> 4)) & 0xF0F0F0F0F0F0F0FUL) * 0x101010101010101UL) >> 56
|
|
);
|
|
}
|
|
|
|
}
|
|
|
|
} // namespace Nuclex.Support
|