diff --git a/llvm/lib/Analysis/DataStructure/DataStructure.cpp b/llvm/lib/Analysis/DataStructure/DataStructure.cpp index f2817623d220..6371196c1f7d 100644 --- a/llvm/lib/Analysis/DataStructure/DataStructure.cpp +++ b/llvm/lib/Analysis/DataStructure/DataStructure.cpp @@ -1039,12 +1039,29 @@ void DSGraph::removeDeadNodes(unsigned Flags) { // Mark all nodes reachable by (non-global) scalar nodes as alive... for (hash_map::iterator I = ScalarMap.begin(), - E = ScalarMap.end(); I != E; ++I) - if (!isa(I->first)) - I->second.getNode()->markReachableNodes(Alive); - else { // Keep track of global nodes - GlobalNodes.push_back(std::make_pair(I->first, I->second.getNode())); + E = ScalarMap.end(); I != E; ) + if (isa(I->first)) { // Keep track of global nodes assert(I->second.getNode() && "Null global node?"); + GlobalNodes.push_back(std::make_pair(I->first, I->second.getNode())); + ++I; + } else { + // Check to see if this is a worthless node generated for non-pointer + // values, such as integers. Consider an addition of long types: A+B. + // Assuming we can track all uses of the value in this context, and it is + // NOT used as a pointer, we can delete the node. We will be able to + // detect this situation if the node pointed to ONLY has Unknown bit set + // in the node. In this case, the node is not incomplete, does not point + // to any other nodes (no mod/ref bits set), and is therefore + // uninteresting for data structure analysis. If we run across one of + // these, prune the scalar pointing to it. + // + DSNode *N = I->second.getNode(); + if (N->NodeType == DSNode::UnknownNode && !isa(I->first)) { + ScalarMap.erase(I++); + } else { + I->second.getNode()->markReachableNodes(Alive); + ++I; + } } // The return value is alive as well...