[llvm] r310474 - [DAG] Explicitly cleanup merged load values during store merge. NFCI.

[Nirav Dave via llvm-commits]

Author: niravd
Date: Wed Aug  9 06:37:07 2017
New Revision: 310474

URL: http://llvm.org/viewvc/llvm-project?rev=310474&view=rev
Log:
[DAG] Explicitly cleanup merged load values during store merge. NFCI.

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=310474&r1=310473&r2=310474&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Wed Aug  9 06:37:07 2017
@@ -13182,9 +13182,15 @@ bool DAGCombiner::MergeConsecutiveStores
                                     SDValue(NewLoad.getNode(), 1));
     }
 
-    // Replace the all stores with the new store.
-    for (unsigned i = 0; i < NumElem; ++i)
+    // Replace the all stores with the new store. Recursively remove
+    // corresponding value if its no longer used.
+    for (unsigned i = 0; i < NumElem; ++i) {
+      SDValue Val = StoreNodes[i].MemNode->getOperand(1);
       CombineTo(StoreNodes[i].MemNode, NewStore);
+      if (Val.getNode()->use_empty())
+        recursivelyDeleteUnusedNodes(Val.getNode());
+    }
+
     RV = true;
     StoreNodes.erase(StoreNodes.begin(), StoreNodes.begin() + NumElem);
     continue;