[Mlir-commits] [flang] [mlir] [mlir][CSE] Introduce hoist-pure-ops logic to CSE pass (PR #180556)

[lonely eagle]

linuxlonelyeagle wrote:

> > This means that although I am hoisting operations here, it does not fundamentally change the relative positioning of blocks within the region. Therefore, DominanceInfo and PostDominanceInfo remain valid.
> 
> Contrary to LLVM, we do have regions: when we CSE an operation with regions it means we're deleting blocks. Are we deleting the entry for these regions in the analysis cache?

Thanks for bringing this up. It really pushed me to think more deeply about this issue. To be honest, this issue still persists in the original CSE, such as in the `cse_multiple_regions test`. I need to investigate this further. Let me give it some more thought and get back to you.😉

https://github.com/llvm/llvm-project/pull/180556