We compared the runtime performance of GraalSqueak with OpenSmalltalkVM (formerly Cog) and RSqueak (RPython-based VM) in Figure 4 of our MPLR’19 paper [1] for the first time. Since then, we've worked on a couple of performance optimizations. So at the moment, I think GraalSqueak is only slower in the DeltaBlue benchmark... in all others, it's (often significantly) better than OpenSmalltalkVM. However, please also note its limitations which we discussed in section 5.2, especially with regard to Smalltalk's interrupt handler and Partial Evaluation performed by the Graal compiler.

So far, I'd say our observations wrt RPython match the ones discussed in "Tracing vs. Partial Evaluation" [2]: Language implementers have to do more work in Truffle, but probably get better peak performance in return (not talking about warmup or memory consumption here).

RE "a more optimized bytecode" set: Sista [3] (an extension of the OpenSmalltalkVM) is doing something like that, too. I'd guess performance would be more or less the same using GraalVM as Truffle produces highly specialized code. But, of course, this would need to be benchmarked. The advantage of the Sista approach is that it's managed on the image level, so specialized versions of methods are persisted as part of the image. AFAIK the GraalVM team is working toward persisting compiled code caches, which is kind of similar but on the level of the language implementation framework.

Hope this answers your questions!

[1] https://fniephaus.com/2019/mplr19-graalsqueak.pdf [2] https://stefan-marr.de/papers/oopsla-marr-ducasse-meta-traci... [3] https://hal.inria.fr/hal-01596321/document