In addition to other comments, as I understand, bootstrapped Forth and similar languages usually compile down to code that is not optimal speed-wise, but a lot more compact that usual, because it's basically all CALL instructions (i.e. every word definition defines a function, and every use of the word inside the definition is a call to the corresponding function). This can be a desirable trade-off when you're dealing with a platform that has, say, 8 kilobytes of RAM to work with for all your code.