Fast Byte Array Compare

FastByteArrayCompare.cs

/// <summary>
/// Compare if given two byte arrays are identical.
/// </summary>
/// <param name="x">byte array to compare.</param>
/// <param name="y">byte array to compare.</param>
/// <returns>true if x and y are identical.</returns>
public unsafe static bool ByteArrayCompare(byte[] x, byte[] y)
{
    if (x == null || y == null || x.Length != y.Length)
    {
        return false;
    }

    fixed (byte* px = x, py = y)
    {
        byte* ex = px, ey = py;
        int l = x.Length;
        for (int i = 0; i < l / 8; i++, ex += 8, ey += 8)
        {
            if (*((long*)ex) != *((long*)ey))
            {
                return false;
            }
        }

        if ((l & 4) != 0)
        {
            if (*((int*)ex) != *((int*)ey))
            {
                return false;
            }
            ex += 4;
            ey += 4;
        }

        if ((l & 2) != 0)
        {
            if (*((short*)ex) != *((short*)ey))
            {
                return false;
            }
            ex += 2;
            ey += 2;
        }

        if ((l & 1) != 0)
        {
            if (*ex != *ey)
            {
                return false;
            }
        }

        return true;
    }
}