code: private static long SBOG_LPSti64(Int512 t, int i) {
          return (StreebogTables.sbob_sl64[0][t.getByte(i) & 0xFF] ^
                  StreebogTables.sbob_sl64[1][t.getByte(i + 8) & 0xFF] ^
                  StreebogTables.sbob_sl64[2][t.getByte(i + 16) & 0xFF] ^
                  StreebogTables.sbob_sl64[3][t.getByte(i + 24) & 0xFF] ^
                  StreebogTables.sbob_sl64[4][t.getByte(i + 32) & 0xFF] ^
                  StreebogTables.sbob_sl64[5][t.getByte(i + 40) & 0xFF] ^
                  StreebogTables.sbob_sl64[6][t.getByte(i + 48) & 0xFF] ^
                  StreebogTables.sbob_sl64[7][t.getByte(i + 56) & 0xFF]);
      }
docs: sbob_sl64[6][t.b[i + 48]] ^ sbob_sl64[7][t.b[i + 56]])