[PATCH] D47139: [NaryReassociate] Detect deleted instr with WeakTrackingVH

[Sanjoy Das via Phabricator via llvm-commits]

sanjoy requested changes to this revision.
sanjoy added inline comments.
This revision now requires changes to proceed.


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Comment at: lib/Transforms/Scalar/NaryReassociate.cpp:243
           I->replaceAllUsesWith(NewI);
-          // If SeenExprs constains I's WeakTrackingVH, that entry will be
-          // replaced with
-          // nullptr.
+          WeakTrackingVH NewIExist = NewI;
+          // If SeenExprs and NewIExist contains I's WeakTrackingVH, that entry
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You probably want `WeakVH` instead of `WeakTrackingVH` here.  However, did you consider lazily deleting `&*I` instead of doing them in this loop?  You could keep an `std::vector` of `WeakVH`s that are pending delete and delete them after leaving this loop.


Repository:
  rL LLVM

https://reviews.llvm.org/D47139