[PATCH] D33675: [DAG] Do MergeConsecutiveStores again before Instruction Selection

[Nirav Dave via Phabricator via llvm-commits]

niravd added a comment.

It's about a 5% time increase for the sum of DAG Combine phases on the my bad test cases for store merge (large basic blocks with a large number of stores which are offset from the same base, but non-mergeable stores). It looks closer to 2% on the total. In the majority of cases, the effect is negligible.

A simple caching check on the PersistantID could remove most of the redundant work. I had plans on looking at a more efficient version of this pass of this once the pre-legal type merge was removed and the nodes are more stable.


https://reviews.llvm.org/D33675