Comment by vocx2tx

> I feel like Go already went through a whole saga of this where the community started with "LLVM and SSA are bad and slow"

I've been a contributor since the Go compiler was a tree-based C program and I've never heard anyone say that. What they said (and it's in the Go FAQ page) is: "At the beginning of the project we considered using LLVM for gc but decided it was too large and slow to meet our performance goals." [1]

If you're building a language with the explicit goal to make it compile fast, it's objectively true that starting out with LLVM is not the best approach. You'll get incredible runtime performance of the generated code since the early days, but NOT fast compilation. The Go makers choose a different tradeoff.

> and they end up building their own SSA IR

They switched to a SSA IR because it was a good idea to begin with, after an initial phase with the tree-base prototype. I've also never heard anyone argue that "SSA is bad", despite what you claim. The first compiler was tree-based because they reused a simple tree-based C compiler from plan9.

> building their own SSA IR and spending a bunch of time trying to bring compilation time closer to what it was before as it made everything much slower

The new compiler was ported to Go (machine-rewritten from C) and that's the main reason it was ~2x slower than the old compiler. It's not due to the switch to a SSA-IR.

[1] https://go.dev/doc/faq#Implementation