[PATCH] D136201: [InstCombine] Replace alloca with phi uses

[Anshil Gandhi via Phabricator via llvm-commits]

gandhi21299 added inline comments.


================
Comment at: llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp:261
+      for (unsigned I = 0; I < PHI->getNumIncomingValues(); ++I)
+        Worklist.insert(cast<Instruction>(PHI->getIncomingValue(I)));
+      Worklist.insert(PHI);
----------------
gandhi21299 wrote:
> nikic wrote:
> > Why do we need to add the phi incoming values to the worklist? Can't this use the same code as bitcast/GEP?
> > 
> > Also, I think it would be good to add a test involving a loop phi, because I think as written, this code might go into infinite recursion in that case.
> I suppose the incoming values would have already been inserted prior to collecting users of the PHI. Thanks!
> 
> A loop test sounds like a great idea!
@nikic Never mind, the incoming values are missing in the `WorkMap` when PHIs are being replaced `replace` if I skip inserting them.


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  https://reviews.llvm.org/D136201/new/

https://reviews.llvm.org/D136201