Index: include/clang/StaticAnalyzer/Core/AnalyzerOptions.h
===================================================================
--- include/clang/StaticAnalyzer/Core/AnalyzerOptions.h
+++ include/clang/StaticAnalyzer/Core/AnalyzerOptions.h
@@ -191,6 +191,7 @@
   enum class ExplorationStrategyKind {
     DFS,
     BFS,
+    UnexploredFirst,
     BFSBlockDFSContents,
     NotSet
   };
Index: include/clang/StaticAnalyzer/Core/PathSensitive/WorkList.h
===================================================================
--- include/clang/StaticAnalyzer/Core/PathSensitive/WorkList.h
+++ include/clang/StaticAnalyzer/Core/PathSensitive/WorkList.h
@@ -83,6 +83,7 @@
   static std::unique_ptr<WorkList> makeDFS();
   static std::unique_ptr<WorkList> makeBFS();
   static std::unique_ptr<WorkList> makeBFSBlockDFSContents();
+  static std::unique_ptr<WorkList> makeUnexploredFirst();
 };
 
 } // end GR namespace
Index: lib/StaticAnalyzer/Core/AnalyzerOptions.cpp
===================================================================
--- lib/StaticAnalyzer/Core/AnalyzerOptions.cpp
+++ lib/StaticAnalyzer/Core/AnalyzerOptions.cpp
@@ -58,23 +58,25 @@
 AnalyzerOptions::ExplorationStrategyKind
 AnalyzerOptions::getExplorationStrategy() {
   if (ExplorationStrategy == ExplorationStrategyKind::NotSet) {
-    StringRef StratStr = Config.insert(
-            std::make_pair("exploration_strategy", "dfs")).first->second;
-    ExplorationStrategy = llvm::StringSwitch<ExplorationStrategyKind>(StratStr)
-      .Case("dfs", ExplorationStrategyKind::DFS)
-      .Case("bfs", ExplorationStrategyKind::BFS)
-      .Case("loopstack_priority", ExplorationStrategyKind::LoopstackPriority)
-      .Case("bfs_block_dfs_contents", ExplorationStrategyKind::BFSBlockDFSContents)
-      .Default(ExplorationStrategyKind::NotSet);
-    assert(ExplorationStrategy != ExplorationStrategyKind::NotSet
-        && "User mode is invalid.");
+    StringRef StratStr =
+        Config
+            .insert(std::make_pair("exploration_strategy", "dfs"))
+            .first->second;
+    ExplorationStrategy =
+        llvm::StringSwitch<ExplorationStrategyKind>(StratStr)
+            .Case("dfs", ExplorationStrategyKind::DFS)
+            .Case("bfs", ExplorationStrategyKind::BFS)
+            .Case("unexplored_first",
+                  ExplorationStrategyKind::UnexploredFirst)
+            .Case("bfs_block_dfs_contents",
+                  ExplorationStrategyKind::BFSBlockDFSContents)
+            .Default(ExplorationStrategyKind::NotSet);
+    assert(ExplorationStrategy != ExplorationStrategyKind::NotSet &&
+           "User mode is invalid.");
   }
   return ExplorationStrategy;
-
 }
 
-
-
 IPAKind AnalyzerOptions::getIPAMode() {
   if (IPAMode == IPAK_NotSet) {
 
Index: lib/StaticAnalyzer/Core/CoreEngine.cpp
===================================================================
--- lib/StaticAnalyzer/Core/CoreEngine.cpp
+++ lib/StaticAnalyzer/Core/CoreEngine.cpp
@@ -19,6 +19,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
 #include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/DenseSet.h"
 #include "llvm/Support/Casting.h"
 
 using namespace clang;
@@ -128,6 +129,78 @@
   return llvm::make_unique<BFSBlockDFSContents>();
 }
 
+class UnexploredFirstStack : public WorkList {
+
+  /// Stack of nodes known to have statements we have not traversed yet.
+  SmallVector<WorkListUnit, 20> StackUnexplored;
+
+  /// Stack of all other nodes.
+  SmallVector<WorkListUnit, 20> StackOthers;
+
+  // FIXME: at the moment, no built-in DenseMapInfo exists for std::tuple.
+  typedef std::pair<std::pair<const Stmt *, int>, const StackFrameContext *>
+      LocIdentifier;
+
+  llvm::DenseSet<LocIdentifier> reachable;
+
+public:
+  bool hasWork() const override {
+    return !(StackUnexplored.empty() && StackOthers.empty());
+  }
+
+  void enqueue(const WorkListUnit &U) override {
+    const ExplodedNode *N = U.getNode();
+    auto BE = N->getLocation().getAs<BlockEdge>();
+
+    if (!BE || !BE->getSrc()->getTerminator()) {
+      // Assume unexplored.
+      StackUnexplored.push_back(U);
+      return;
+    }
+
+    const Stmt *S = BE->getSrc()->getTerminator();
+    int ChildNo = findChildNo(*BE);
+    LocIdentifier LocId =
+        std::make_pair(std::make_pair(S, ChildNo), N->getStackFrame());
+
+    if (!reachable.count(LocId)) {
+      StackUnexplored.push_back(U);
+    } else {
+      StackOthers.push_back(U);
+    }
+    reachable.insert(LocId);
+  }
+
+  WorkListUnit dequeue() override {
+    if (!StackUnexplored.empty()) {
+      WorkListUnit &U = StackUnexplored.back();
+      StackUnexplored.pop_back();
+      return U;
+    } else {
+      WorkListUnit &U = StackOthers.back();
+      StackOthers.pop_back();
+      return U;
+    }
+  }
+
+private:
+  int findChildNo(BlockEdge& BE) {
+    int ChildNo = 0;
+    for (const CFGBlock *Succ : BE.getSrc()->succs()) {
+      if (Succ == BE.getDst())
+        break;
+
+      ChildNo++;
+    }
+    assert(ChildNo < BE.getSrc()->succ_size());
+    return ChildNo;
+  }
+};
+
+std::unique_ptr<WorkList> WorkList::makeUnexploredFirst() {
+  return llvm::make_unique<UnexploredFirstStack>();
+}
+
 //===----------------------------------------------------------------------===//
 // Core analysis engine.
 //===----------------------------------------------------------------------===//
@@ -140,8 +213,8 @@
       return WorkList::makeBFS();
     case AnalyzerOptions::ExplorationStrategyKind::BFSBlockDFSContents:
       return WorkList::makeBFSBlockDFSContents();
-    case AnalyzerOptions::ExplorationStrategyKind::LoopstackPriority:
-      return WorkList::makePriorityQueue();
+    case AnalyzerOptions::ExplorationStrategyKind::UnexploredFirst:
+      return WorkList::makeUnexploredFirst();
     default:
       llvm_unreachable("Unexpected case");
   }