What exactly is the followup here? I see the extra test added that ensures ctlz is not lowered when the flag is disabled. Is another test helpful?

I can fix it Monday morning. A rollback is fine if it's urgent.

I'm not able to get to my computer til Monday, but perhaps your issue is
that this feature is disabled by default (see comments above), and you need
to explicitly enable it. The test files in this patch show the invocation.

@vzakhari ping :) thanks for your review and advice!

(btw, I don't have commit access, so someone else will need to commit it for me)

This time only Bazel failed, so ok to merge :)

Try syncing with head

break -> continue, plus move mlir-cpu-runner

Fixed a typo/bad variable name choice from the last update

Sorry for the delay, I was in Korea at a conference.

Address reviewer comments

Added default-disabled convert-ctlz option

The backend we're ultimately planning to support does not have a ctlz builtin, so we have no choice but to emulate it in software. This is why lowering to llvm's builtin doesn't help us (and IIUC CIRCT also doesn't support llvm's ctlz)

Added mlir-cpu-runner tests for ctlz