[Mlir-commits] [mlir] [mlir] Add normalize pass to MLIR (PR #186647)

[Renato Golin]

rengolin wrote:

> I think this PR and the pass description would likely benefit from describing the goals and intend of this pass. It's not trying to be an optimization pass (so things like undoing LICM seem fine to me) IIRC. Rather it is trying to increase syntactic equivalence of code to reduce diff size while retaining semantic equivalence right?

I see. In that sense, undoing LICM is fine, but assuming unknown ops' region semantics isn't. If an operation overrides the `walk` method and traverse its own regions, does it (have to) know that some pass wants to move operations inside/outside without its knowledge?

Also, in this light, @arun-thmn's pass is specifically for controlling instruction selection, so unlikely to match semantics with this one (ie. ignore that comment).

https://github.com/llvm/llvm-project/pull/186647