[PATCH] D111533: [SCEV] Invalidate user SCEVs along with operand SCEVs to avoid cache corruption

[Nikita Popov via Phabricator via llvm-commits]

nikic added a comment.

In D111533#3089254 <https://reviews.llvm.org/D111533#3089254>, @mkazantsev wrote:

> Upon that, I'm going to merge it tomorrow if there will be no objections.

Yeah, feel free. I didn't have time to work on this and don't want to hold it up further.



================
Comment at: llvm/lib/Analysis/ScalarEvolution.cpp:12849
   SmallPtrSet<const SCEV *, 8> ToForget(SCEVs.begin(), SCEVs.end());
+  SmallVector<const SCEV *, 8> Worklist(SCEVs.begin(), SCEVs.end());
+
----------------
Might make sense to initialize this from `ToForget` to avoid duplicates in the initial worklist?


================
Comment at: llvm/lib/Analysis/ScalarEvolution.cpp:12877
           if (any_of(ToForget,
                      [&BEInfo](const SCEV *S) { return BEInfo.hasOperand(S); }))
             Map.erase(I++);
----------------
Hm ... we don't really need to consider user SCEVs here, as the used SCEV will be part of the operands as well.

Alternatively, if we're already considering user SCEVs, we no longer need the hasOperand() approach, we could directly check whether `ENT.ExactNotTaken == S`.


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