My point was that the first optimizing compiler isn't comparable with what is expected of a modern compiler, so please don't compare their code & memory footprint. With the first fortran compiler it was garbage in, garbage out. A modern compiler can (often) turn garbage into fast code.

Nowadays inside a compiler it's 90% graph processing & reprocessing. Since you're dealing with (cyclic) graphs, garbage collection is very useful and if you don't use some automated gc, you'll probably roll you own in one way or anther.

And a X86 interpreter isn't comparable with a compiler either. I doubt that there was any GC going on in your example, everything probably runs in a single array that represents the memory. Maybe some temporary objects but JS engines have good generational GC these days, I don't think D uses a generational GC algorithm.