I'm often skeptical of the desire to create a lot of passes. In the early Vale compiler, and in the Mojo compiler, we were paying a lot of interest on tech debt because features were put in the wrong pass. We often incurred more complexity trying to make a concept work across passes than we would have had in fewer, larger passes. I imagine this also has analogies to microservices in some way. Maybe other compiler people can weigh in here on the correct number/kind of passes.
I'm creating a language/compiler now, and I'm quite certain that I did not have enough passes initially, but I hope I'm at a good spot now - but time will tell.
Wouldn't this kind of architecture yield a slower compiler, regardless of output quality? Conceptually, trying to implement the least-amount of passes with each doing as much work as possible would make more sense to me.
I agree with the notion that having multiple passes makes compilers easier to understand and maintain but finding the right number of passes is the real challenge here.
The optimal number of passes/IRs depends heavily on what language is being compiled. Some languages naturally warrant this kind of an architecture that would involve a lot of passes.
Compiling Scheme for instance would naturally entail several passes.
It could look something like the following:
Bottlenecks are changing and it's pretty interesting.
I'm creating a language/compiler now, and I'm quite certain that I did not have enough passes initially, but I hope I'm at a good spot now - but time will tell.
The optimal number of passes/IRs depends heavily on what language is being compiled. Some languages naturally warrant this kind of an architecture that would involve a lot of passes.
Compiling Scheme for instance would naturally entail several passes. It could look something like the following:
Lexer -> Parser -> Macro Expander -> Alpha Renaming -> Core AST (Lowering) -> CPS Transform -> Beta / Eta Reduction -> Closure Conversion -> Codegen