[llvm] r342983 - [DAGCombine] Share predecessor bookkeeping in CombineToPostIndexedLoadStore. NFCI.

[Nirav Dave via llvm-commits]

Author: niravd
Date: Tue Sep 25 08:29:04 2018
New Revision: 342983

URL: http://llvm.org/viewvc/llvm-project?rev=342983&view=rev
Log:
[DAGCombine] Share predecessor bookkeeping in CombineToPostIndexedLoadStore. 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=342983&r1=342982&r2=342983&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Tue Sep 25 08:29:04 2018
@@ -12701,8 +12701,15 @@ bool DAGCombiner::CombineToPostIndexedLo
       if (TryNext)
         continue;
 
-      // Check for #2
-      if (!Op->isPredecessorOf(N) && !N->isPredecessorOf(Op)) {
+      // Check for #2.
+      SmallPtrSet<const SDNode *, 32> Visited;
+      SmallVector<const SDNode *, 8> Worklist;
+      // Ptr is predecessor to both N and Op.
+      Visited.insert(Ptr.getNode());
+      Worklist.push_back(N);
+      Worklist.push_back(Op);
+      if (!SDNode::hasPredecessorHelper(N, Visited, Worklist) &&
+          !SDNode::hasPredecessorHelper(Op, Visited, Worklist)) {
         SDValue Result = isLoad
           ? DAG.getIndexedLoad(SDValue(N,0), SDLoc(N),
                                BasePtr, Offset, AM)