[PATCH] D68488: [PATCH 05/38] [noalias] [IR] Introduce noalias_sidechannel for LoadInst/StoreInst

[Andrei Elovikov via Phabricator via llvm-commits]

a.elovikov added inline comments.


================
Comment at: llvm/lib/IR/Instructions.cpp:4149
+  //   that don't know how to handle it (Like MergeLoadStoreMotion shows)
+  // - safe alternative: keep the argument, but map it to undef.
+  if (hasNoaliasSideChannelOperand())
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Why is it safe? Consider we have aliasing load and store, we clone them so load.clone and load.store now have undef in the sidechannels, so optimizations are free to choose the values for them that would mean noalias.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D68488/new/

https://reviews.llvm.org/D68488