Cog/Frameworks/libatrac9/libatrac9/LibAtrac9/CSharp/LibAtrac9/Utilities/Bit.cs

22 lines
914 B
C#

namespace LibAtrac9.Utilities
{
internal static class Bit
{
private static uint BitReverse32(uint value)
{
value = ((value & 0xaaaaaaaa) >> 1) | ((value & 0x55555555) << 1);
value = ((value & 0xcccccccc) >> 2) | ((value & 0x33333333) << 2);
value = ((value & 0xf0f0f0f0) >> 4) | ((value & 0x0f0f0f0f) << 4);
value = ((value & 0xff00ff00) >> 8) | ((value & 0x00ff00ff) << 8);
return (value >> 16) | (value << 16);
}
private static uint BitReverse32(uint value, int bitCount) => BitReverse32(value) >> (32 - bitCount);
public static int BitReverse32(int value, int bitCount) => (int) BitReverse32((uint) value, bitCount);
public static int SignExtend32(int value, int bits)
{
int shift = 8 * sizeof(int) - bits;
return (value << shift) >> shift;
}
}
}