Antlr4.Runtime.Sharpen.BitSet.BitScanForward C# (CSharp) Метод

        private static int BitScanForward(ulong value)
        {
            if (value == 0)
                return -1;

            const ulong debruijn64 = 0x03f79d71b4cb0a89;
            return index64[((value ^ (value - 1)) * debruijn64) >> 58];
        }