Hi,

I'm using Cranelift with opt_level=speed_and_size in a project and have run into a hang after updating to the current main branch of the wasmtime/cranelift repository. Git bisect points to this commit: b772c31ef "Cranelift: update to regalloc2 0.11.3."

My original reproducer is a single large Cranelift function (~30kb) that compiled almost instantly with the previous commit but hangs after the regalloc2 update. I'm not sure if the regression can also be triggered by WebAssembly modules.

$ time ./clif-util-bad compile --target=x86_64 --set opt_level=speed regression.clif
^C
Executed in   41.20 secs
$ time ./clif-util-good compile --target=x86_64 --set opt_level=speed regression.clif
Executed in   16.72 millis

Thanks!

CC #214 since this is the only change between 0.11.2 and 0.11.3

regression.clif.txt

reduced.clif.txt

BTW: Is there a way to reduce hangs/timeouts with clif-util bugpoint? I've hacked something together using shrinkray but I'm not fully convinced of the process. Cranelift-native tooling should probably be more effective 🙂