[Mlir-commits] [mlir] [OpenMP Dialect] Add omp.canonical_loop operation. (PR #65380)

[Kiran Chandramohan]

kiranchandramohan wrote:

> > If an optimization makes a change that violates the invariant will the compiler assert?
> 
> Yes, that will be a compilation failure. @Meinersbur would it be okay if we do loop transforms within MLIR in the very beginning to avoid such optimization issues? I understand that it is not in line with the aim of using OpenMPIRBuilder for common OpenMP stuff, but it would ensure correctness.

It is not clear which transformation/optimization would cause this issue. Can this be fixed by:
-> Performing the transformation at the location of the canonical loop?
-> Adding appropriate side-effects to ensure operations do not come in between the transform operations and the canonical loop?

In general, choosing a flow other than the OpenMPIRBuilder should be the last resort. It will require a discussion outside this Pull Request involving the llvm OpenMP folks (who pushed for this flow) and the MLIR team (who agreed to this flow).

https://github.com/llvm/llvm-project/pull/65380