[Mlir-commits] [mlir] [mlir][Transforms] `OneToNTypeConversion.cpp`: Fix invalid IR (PR #77922)

[Ingo Müller]

https://github.com/ingomueller-net approved this pull request.

Awesome work on `MLIR_ENABLE_EXPENSIVE_PATTERN_API_CHECKS`! Thanks for looking into the 1:n conversion as well!

Some questions, one small request:

* What's the plan for enabling `MLIR_ENABLE_EXPENSIVE_PATTERN_API_CHECKS` as part of CI? Should there *not* be a plan to enable it eventually, would there be any way to test the code otherwise?
* Can you confirm the following reasoning? The proposed fix is valid because if the previous result types are converted to "no result types", then there cannot be any consumers of the results, so no consumer need any cast. Furthermore, the cast is supposed to disappear anyways, so we wouldn't in any case rely on the fact that there is a user of the inputs either (for example, to prevent DCE).
* Could you add a brief sentence to the function documentation about this edge case?

https://github.com/llvm/llvm-project/pull/77922