diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index bdb32ed78f4..ad09869d27b 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -120,18 +120,22 @@ namespace { std::vector NowDead; DAG.ReplaceAllUsesOfValueWith(TLO.Old, TLO.New, NowDead); - // Push the new node and any (now) users onto the worklist. + // Push the new node and any (possibly new) users onto the worklist. WorkList.push_back(TLO.New.Val); AddUsersToWorkList(TLO.New.Val); // Nodes can end up on the worklist more than once. Make sure we do // not process a node that has been replaced. - removeFromWorkList(TLO.Old.Val); for (unsigned i = 0, e = NowDead.size(); i != e; ++i) removeFromWorkList(NowDead[i]); - // Finally, since the node is now dead, remove it from the graph. - DAG.DeleteNode(TLO.Old.Val); + // Finally, if the node is now dead, remove it from the graph. The node + // may not be dead if the replacement process recursively simplified to + // something else needing this node. + if (TLO.Old.Val->use_empty()) { + removeFromWorkList(TLO.Old.Val); + DAG.DeleteNode(TLO.Old.Val); + } return true; }