[PATCH] D111602: [SCEV][NFC] Tackle quadratic CT consumption when forgetting memoized results

[Philip Reames via Phabricator via llvm-commits]

reames added a comment.

Two minor opportunities to exploit set invalidation for efficiency.  I'll leave it to you whether these are worth separate review or not.



================
Comment at: llvm/lib/Analysis/ScalarEvolution.cpp:12839
     std::pair<const SCEV *, const Loop *> Entry = I->first;
     if (Entry.first == S)
       PredicatedSCEVRewrites.erase(I++);
----------------
There's an opportunity to exploit the invalidation of sets at a time here by replacing multiple walks, with one walk and a set membership check.  


================
Comment at: llvm/lib/Analysis/ScalarEvolution.cpp:12849
           BackedgeTakenInfo &BEInfo = I->second;
           if (BEInfo.hasOperand(S))
             Map.erase(I++);
----------------
Same here.  Though, I don't believe we have an set optimized contains_any already, so this might not be worth bothering with.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D111602/new/

https://reviews.llvm.org/D111602