[PATCH] D73758: Conservative fix for DSE across loops

[Karl Rehm via Phabricator via llvm-commits]

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Looks like @fhahn posted a proper fix for this almost at the exact same time that I posted this one. Heh.


This is essentially just https://reviews.llvm.org/D68006 with a few fixes for the comments.

To address the last comment about the CFG visiting: This simply prevents DSE from analyzing through back-edges (and instead assuming memory modification) because it had the potential to break certain types of loops. I heard somewhere that there will be a proper fix for this in @fhahn 's MemorySSA-backed DSE, so this is essentially a band-aid I suppose.

Don't know who to tag for this, sorry.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D73758

Files:
  llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp

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