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

[Nirav Dave via Phabricator via llvm-commits]

niravd 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;
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rnk wrote:
> 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.
Seems reasonable. Changing this allows some reordering of statepoint updates.


https://reviews.llvm.org/D33345