[Mlir-commits] [mlir] [mlir][arith] Add more canonicalization and integration tests coverage (PR #92272)

[Jacob Yu]

pingshiyu wrote:

> I don't follow this comment. Unit tests are there specifically to verify that the corresponding pattern is correct. In addition, every pattern is verified through code-review.

As far as I can see, unit tests don't verify that a pattern is correct: I mean correct in the sense that for a pattern `source -> target`, `source` and `target` have the same semantics, in all contexts. Unit tests only check that the pattern is _applied_.

> An e2e would/will help, yes, but should be considered as complementary to a spec rather than a replacement.

Oh yes absolutely! It was never the intention to replace formal semantics with e2e tests :) During working on this PR and conversation in this thread I realised that integration tests would fill in some _testing gaps_ in the correctness of rewrite patterns, that are not covered by unit tests.

https://github.com/llvm/llvm-project/pull/92272