This is certainly possible: Break up large functions, and then the bounded maximum function size can be your O(1) chunk size, to be processed in a streaming manner without dynamic allocation.
However, breaking up huge functions (or skipping optimizations on them) will lead to missed opportunities. And LTO-style optimizations, where the entire program is taken into account, can be very important as well (as a concrete example, we see huge benefits from doing that in wasm-opt for Wasm GC).
Still, it's a nice idea, and maybe it can make 80% of compiler passes a lot faster!
However, breaking up huge functions (or skipping optimizations on them) will lead to missed opportunities. And LTO-style optimizations, where the entire program is taken into account, can be very important as well (as a concrete example, we see huge benefits from doing that in wasm-opt for Wasm GC).
Still, it's a nice idea, and maybe it can make 80% of compiler passes a lot faster!