[PATCH] D33345: [DAG] Improve Aliasing of operations to static alloca

[Reid Kleckner via Phabricator via llvm-commits]

rnk added inline comments.


================
Comment at: lib/CodeGen/SelectionDAG/DAGCombiner.cpp:16614-16615
+      MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
+      if (MFI.getObjectAllocation(A->getIndex()) ||
+          MFI.getObjectAllocation(B->getIndex()))
+        return false;
----------------
I think we could strengthen this to `!MFI.isFixedObjectIndex(A->getIndex())`. Fixed objects have offsets, and all non-fixed objects will be allocated in non-overlapping memory during PEI regardless of whether they have allocas or not.


https://reviews.llvm.org/D33345