Auto tree cutter

while true do
    turtle.suckDown()
    if turtle.compare()==false then
        sleep(1)
        turtle.digUp()
        turtle.up()
        turtle.dig()
        turtle.forward()
        turtle.digDown()
        turtle.placeDown()
        while true do
            turtle.digUp()
            turtle.up()
            if turtle.digUp()==false then
                break
            end
        end
        while turtle.down()==true do
            turtle.down()
        end
        turtle.back()
        turtle.down()
    end
end