[llvm] [LoadStoreVectorizer] Allow redundant stores (PR #169946)

[Artem Belevich via llvm-commits]

Artem-B wrote:

I'm biased towards separation of functionality. 

> major IR transform happens after the last call of DSE, which creates new case of DSE.
> We either need to add another DSE pass somewhere, or we add DSE-like capability here.

There may be other options. This sounds like a good case for improving DSE and let it iterate over the function, again, as long as it makes progress. Eliminating memory accesses is usually worth the effort, and we can always add knobs to curb its enthusiasm.

Adding another instance of DSE pass as is, as a back-end specific pass would also be OK, IMO. We do something similar with SROA already, for NVPTX.


https://github.com/llvm/llvm-project/pull/169946