[PATCH] D38862: Add must alias info to ModRefInfo.

[Nuno Lopes via Phabricator via llvm-commits]

nlopes added inline comments.


================
Comment at: lib/Analysis/AliasAnalysis.cpp:506
+    if (AR == MustAlias)
+      return MRI_MustModRef;
+  }
----------------
nlopes wrote:
> AtomicCmpXchgInst must read, but may not write (depending on the value read).
> I think the only safe value here is MRI_ModRef, since the current lattice doesn't have a more precise value for MustRead & MayReadWithMustAlias.
gah, I meant MustRef & MayModWithMustAlias.


https://reviews.llvm.org/D38862