[PATCH] D86156: [BFI] Preserve BFI information through loop passes via VH callbacks inside LoopStandardAnalysisResults

Alina Sbirlea via Phabricator via cfe-commits cfe-commits at lists.llvm.org
Thu Aug 27 12:22:17 PDT 2020


asbirlea added a comment.

Your understanding is correct. I only have one more comment on preserving passes in LICM too.

As a general note, it may make sense to include BFI in the set of loop passes always preserved (`getLoopPassPreservedAnalyses()`), if its nature is to always be preserved (with some potential info loss) due to the callbacks deleting blocks. But since we're only looking at LICM effect for now, this can be a follow up when/if needed.

Please allow some time for nikic@ to take a look too.



================
Comment at: llvm/test/Other/opt-O2-pipeline.ll:281
 ; CHECK-NEXT:         Loop Invariant Code Motion
 ; CHECK-NEXT:       Lazy Branch Probability Analysis
 ; CHECK-NEXT:       Lazy Block Frequency Analysis
----------------
Mark LICM to preserve these passes so they get moved above LICM rather than recomputed here (same as they are preserved in unswitch).


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D86156/new/

https://reviews.llvm.org/D86156



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