[pizlonator]

Worth noting that B3’s biggest win was higher peak throughput. It generated better code than llvm. It achieved that by having an IR that lets us be a lot more precise about things that were important to our front end compiler.

It’s not even about what language you’re compiling. It’s about the IR that goes into llvm or whatever you would use instead of llvm. If that IR generally does C-like things and can only describe types and aliasing to the level of fidelity that C can (I.e. structured assembly with crude hacks that let you sometimes pretend that you have a super janky abstract machine), then llvm is great. Otherwise it’s a missed opportunity.

[gsnedders]

> It achieved that by having an IR that lets us be a lot more precise about things that were important to our front end compiler.

Do you have any examples off-hand? I presume caring about patchpoints and OSR is as fair gain to start with?

[pizlonator]

And aliasing. The aliasing story in B3 is so wonderful. That was one of the biggest wins - being able to say for example that something can side-exit (and can do weird shit after exit) but doesn't write any state if it falls through.