[PATCH] D88778: [MemCpyOpt] Fix MemorySSA preservation

[Alina Sbirlea via Phabricator via llvm-commits]

asbirlea added a comment.

Thank you for fixing this!

Could you clang-format the patch?



================
Comment at: llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp:547
+  MemoryDef *PDef = MSSAU
+      ? cast<MemoryDef>(MSSAU->getMemorySSA()->getMemoryAccess(P)) : nullptr;
   for (auto *I : llvm::reverse(ToLift)) {
----------------
Is it possible for the cast here to fail?
P is known to modify the Load location a the callsite. Is it possible this is true for specific cases not modeled as MemoryDefs in MemorySSA (e.g. when using a non-standard aa pipeline, and basicaa is disabled, certain accesses are seen as "can access/modify" but are ignored in the MemorySSA modeling - see MemorySSA.cpp:1766).


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  https://reviews.llvm.org/D88778/new/

https://reviews.llvm.org/D88778