YJIT benchmarks can be found at https://speed.yjit.org/

The Rust port doesn't change performance much according to the pull request description.

I didn't know this was public, sweet! Nice that the tooling that generates this report is also published: https://github.com/Shopify/yjit-metrics

Yes, but YJIT in rust is the same ~33.4% faster than vanilla CRuby than YJIT in C. The rewrite into Rust is expected to make YJIT easier to maintain and that may in turn make possible further improvements to code generation, but the rewrite generates the same machine code (and therefore the same speedup) as before.

According to the post not much. The Rust version performs about the same because it generates mostly the same machine code.

Very likely, the performance of a JIT comes from:

- the architecture of the JIT itself

- the generated code

AFAIK, the Rust YJIT doesn't change any (they explicitly say that the generated code is approximately the same), so there no significant difference in performance should be expected.

It means completely nothing for performance.

Nothing