diff --git a/dcalc/GraphDelayCalc.cc b/dcalc/GraphDelayCalc.cc
index 6c821dab..8dbcfe47 100644
--- a/dcalc/GraphDelayCalc.cc
+++ b/dcalc/GraphDelayCalc.cc
@@ -395,7 +395,7 @@ GraphDelayCalc::seedRootSlew(Vertex *vertex,
     seedDrvrSlew(vertex, arc_delay_calc);
   else
     seedLoadSlew(vertex);
-  iter_->enqueueAdjacentVertices(vertex);
+  iter_->enqueueFanout(vertex);
 }
 
 void
@@ -686,7 +686,11 @@ GraphDelayCalc::findVertexDelay(Vertex *vertex,
   debugPrint(debug_, "delay_calc", 2, "find delays {} ({})",
              vertex->to_string(this),
              network_->cellName(network_->instance(pin)));
-  if (vertex->isRoot())
+  if (vertex->isRoot()
+      // Bidirect port drivers are enqueued by their load vertex in
+      // annotateLoadDelays.
+      || (vertex->isBidirectDriver()
+          && network_->isTopLevelPort(pin)))
     seedRootSlew(vertex, arc_delay_calc);
   else {
     if (network_->isLeaf(pin)) {
@@ -703,7 +707,7 @@ GraphDelayCalc::findVertexDelay(Vertex *vertex,
 	  // change when non-incremental to stride past annotations.
 	  if (!incremental_
               || loadSlewsChanged(load_slews_prev, load_pin_index_map))
-	    iter_->enqueueAdjacentVertices(vertex);
+	    iter_->enqueueFanout(vertex);
 	}
       }
       else {
@@ -711,14 +715,9 @@ GraphDelayCalc::findVertexDelay(Vertex *vertex,
 	enqueueTimingChecksEdges(vertex);
 	// Enqueue driver vertices from this input load.
 	if (propagate)
-	  iter_->enqueueAdjacentVertices(vertex);
+	  iter_->enqueueFanout(vertex);
       }
     }
-    // Bidirect port drivers are enqueued by their load vertex in
-    // annotateLoadDelays.
-    else if (vertex->isBidirectDriver()
-	     && network_->isTopLevelPort(pin))
-      seedRootSlew(vertex, arc_delay_calc);
   }
 }
 
diff --git a/graph/Graph.cc b/graph/Graph.cc
index 589e1fa0..b1f40d4c 100644
--- a/graph/Graph.cc
+++ b/graph/Graph.cc
@@ -418,6 +418,8 @@ Graph::makePinVertices(Pin *pin,
                        Vertex *&vertex,
                        Vertex *&bidir_drvr_vertex)
 {
+  vertex = nullptr;
+  bidir_drvr_vertex = nullptr;
   PortDirection *dir = network_->direction(pin);
   if (!dir->isPowerGround()) {
     bool is_reg_clk = network_->isRegClkPin(pin);
@@ -427,8 +429,6 @@ Graph::makePinVertices(Pin *pin,
       bidir_drvr_vertex = makeVertex(pin, true, is_reg_clk);
       pin_bidirect_drvr_vertex_map_[pin] = bidir_drvr_vertex;
     }
-    else
-      bidir_drvr_vertex = nullptr;
   }
 }
 
@@ -581,9 +581,9 @@ Graph::visitFanouts(Vertex *vertex,
                     const VertexFn &fn)
 {
   if (pred->searchFrom(vertex)) {
-    for (Edge *edge = this->edge(vertex->out_edges_);
-         edge;
-         edge = this->edge(edge->vertex_out_next_)) {
+    VertexOutEdgeIterator edge_iter(vertex, graph_);
+    while (edge_iter.hasNext()) {
+      Edge *edge = edge_iter.next();
       Vertex *to_vertex = this->vertex(edge->to_);
       if (pred->searchThru(edge)
           && pred->searchTo(to_vertex))
@@ -598,9 +598,9 @@ Graph::visitFanoutEdges(Vertex *vertex,
                         const EdgeFn &fn)
 {
   if (pred->searchFrom(vertex)) {
-    for (Edge *edge = this->edge(vertex->out_edges_);
-         edge;
-         edge = this->edge(edge->vertex_out_next_)) {
+    VertexOutEdgeIterator edge_iter(vertex, graph_);
+    while (edge_iter.hasNext()) {
+      Edge *edge = edge_iter.next();
       Vertex *to_vertex = this->vertex(edge->to_);
       if (pred->searchThru(edge)
           && pred->searchTo(to_vertex))
@@ -615,9 +615,9 @@ Graph::visitFanins(Vertex *vertex,
                    const VertexFn &fn)
 {
   if (pred->searchFrom(vertex)) {
-    for (Edge *edge = this->edge(vertex->in_edges_);
-         edge;
-         edge = this->edge(edge->vertex_in_next_)) {
+    VertexInEdgeIterator edge_iter(vertex, graph_);
+    while (edge_iter.hasNext()) {
+      Edge *edge = edge_iter.next();
       Vertex *from_vertex = this->vertex(edge->from_);
       if (pred->searchThru(edge)
           && pred->searchFrom(from_vertex))
@@ -632,9 +632,9 @@ Graph::visitFaninEdges(Vertex *vertex,
                        const EdgeFn &fn)
 {
   if (pred->searchFrom(vertex)) {
-    for (Edge *edge = this->edge(vertex->in_edges_);
-         edge;
-         edge = this->edge(edge->vertex_in_next_)) {
+    VertexInEdgeIterator edge_iter(vertex, graph_);
+    while (edge_iter.hasNext()) {
+      Edge *edge = edge_iter.next();
       Vertex *from_vertex = this->vertex(edge->from_);
       if (pred->searchThru(edge)
           && pred->searchFrom(from_vertex))
diff --git a/include/sta/Bfs.hh b/include/sta/Bfs.hh
index 5c11ab1c..c0c24f1e 100644
--- a/include/sta/Bfs.hh
+++ b/include/sta/Bfs.hh
@@ -24,6 +24,7 @@
 
 #pragma once
 
+#include <functional>
 #include <mutex>
 #include <vector>
 
@@ -38,6 +39,8 @@ class SearchPred;
 class BfsFwdIterator;
 class BfsBkwdIterator;
 
+using VertexFn = std::function<void(Vertex*)>;
+
 // LevelQueue is a vector of vertex vectors indexed by logic level.
 using LevelQueue = std::vector<VertexSeq>;
 
@@ -50,26 +53,23 @@ using LevelQueue = std::vector<VertexSeq>;
 // Vertices are marked as being in the queue by using a flag on
 // the vertex indexed by bfs_index.  A unique flag is only needed
 // if the BFS in in use when other BFS's are simultaneously in use.
-class BfsIterator : public StaState,
-                    public Iterator<Vertex*>
+class BfsIterator : public StaState
 {
 public:
   // Make sure that the BFS queue is deep enough for the max logic level.
   void ensureSize();
   // Reset to virgin state.
   void clear();
+  // Apply fn to each vertex and clear.
+  void clear(const VertexFn &fn);
   [[nodiscard]] bool empty() const;
   // Enqueue a vertex to search from.
   void enqueue(Vertex *vertex);
   // Enqueue vertices adjacent to a vertex.
-  void enqueueAdjacentVertices(Vertex *vertex);
-  virtual void enqueueAdjacentVertices(Vertex *vertex,
-                                       const Mode *mode);
+  virtual void enqueueAdjacentVertices(Vertex *vertex) = 0;
   virtual void enqueueAdjacentVertices(Vertex *vertex,
-				       SearchPred *search_pred,
                                        const Mode *mode) = 0;
-  virtual void enqueueAdjacentVertices(Vertex *vertex,
-                                       SearchPred *search_pred) = 0;
+
   [[nodiscard]] bool inQueue(Vertex *vertex);
   void checkInQueue(Vertex *vertex);
   // Notify iterator that vertex will be deleted.
@@ -77,10 +77,6 @@ public:
   void remove(Vertex *vertex);
   void reportEntries() const;
 
-  bool hasNext() override;
-  bool hasNext(Level to_level);
-  Vertex *next() override;
-
   // Apply visitor to all vertices in the queue in level order.
   // Returns the number of vertices that are visited.
   virtual int visit(Level to_level,
@@ -91,6 +87,10 @@ public:
   int visitParallel(Level to_level,
 		    VertexVisitor *visitor);
 
+  bool hasNext();
+  bool hasNext(Level to_level);
+  Vertex *next();
+
 protected:
   BfsIterator(BfsIndex bfs_index,
 	      Level level_min,
@@ -104,10 +104,10 @@ protected:
   virtual bool levelLessOrEqual(Level level1,
 				Level level2) const = 0;
   virtual void incrLevel(Level &level) const = 0;
-  void findNext(Level to_level);
   void deleteEntries();
   void checkLevel(Vertex *vertex,
                   Level level);
+  void findNext(Level to_level);
 
   BfsIndex bfs_index_;
   Level level_min_;
@@ -131,12 +131,13 @@ public:
 		 SearchPred *search_pred,
 		 StaState *sta);
   ~BfsFwdIterator() override;
+  void enqueueAdjacentVertices(Vertex *vertex) override;
   void enqueueAdjacentVertices(Vertex *vertex,
-                              SearchPred *search_pred) override;
-  void enqueueAdjacentVertices(Vertex *vertex,
-			       SearchPred *search_pred,
                                const Mode *mode) override;
   using BfsIterator::enqueueAdjacentVertices;
+  void enqueueFanout(Vertex *vertex);
+  void enqueueFanout(Vertex *vertex,
+                     const Mode *mode);
 
 protected:
   bool levelLessOrEqual(Level level1,
@@ -153,14 +154,17 @@ public:
 		  SearchPred *search_pred,
 		  StaState *sta);
   ~BfsBkwdIterator() override;
+  void enqueueAdjacentVertices(Vertex *vertex) override;
   void enqueueAdjacentVertices(Vertex *vertex,
-                              SearchPred *search_pred) override;
-  void enqueueAdjacentVertices(Vertex *vertex,
-			       SearchPred *search_pred,
                                const Mode *mode) override;
   using BfsIterator::enqueueAdjacentVertices;
+  void enqueueFanin(Vertex *vertex);
+  void enqueueFanin(Vertex *vertex,
+                    const Mode *mode);
 
 protected:
+  void enqueueFanin(Vertex *vertex,
+                    SearchPred *search_pred);
   bool levelLessOrEqual(Level level1,
 			Level level2) const override;
   bool levelLess(Level level1,
diff --git a/include/sta/FilterObjects.hh b/include/sta/FilterObjects.hh
index 71bea6c0..791c6b10 100644
--- a/include/sta/FilterObjects.hh
+++ b/include/sta/FilterObjects.hh
@@ -30,6 +30,7 @@
 
 #include "GraphClass.hh"
 #include "NetworkClass.hh"
+#include "Scene.hh"
 #include "SdcClass.hh"
 #include "SearchClass.hh"
 #include "StringUtil.hh"
@@ -64,6 +65,16 @@ filterClocks(std::string_view filter_expression,
              ClockSeq *clks,
              Sta *sta);
 
+SceneSeq
+filterScenes(std::string_view filter_expression,
+             SceneSeq *scenes,
+             Sta *sta);
+
+ModeSeq
+filterModes(std::string_view filter_expression,
+            ModeSeq *modes,
+            Sta *sta);
+
 LibertyCellSeq
 filterLibCells(std::string_view filter_expression,
                LibertyCellSeq *cells,
diff --git a/include/sta/Property.hh b/include/sta/Property.hh
index 57260cde..84ad5cfc 100644
--- a/include/sta/Property.hh
+++ b/include/sta/Property.hh
@@ -28,6 +28,7 @@
 #include <map>
 #include <string>
 #include <string_view>
+#include <utility>
 
 #include "LibertyClass.hh"
 #include "NetworkClass.hh"
@@ -61,6 +62,118 @@ private:
   std::map<std::string, PropertyHandler, std::less<>> registry_;
 };
 
+// Adding a new property type
+//  value union (string values use std::string* so the union stays trivial)
+//  enum Type
+//  constructor
+//  copy constructor switch clause
+//  move constructor switch clause
+//  operator= &  switch clause
+//  operator= && switch clause
+//  StaTcl.i swig %typemap(out) PropertyValue switch clause
+
+class PropertyValue
+{
+public:
+  enum class Type { none, string, float_, bool_,
+                    library, cell, port,
+                    liberty_library, liberty_cell, liberty_port,
+                    instance, pin, pins, net,
+                    clk, clks, paths, pwr_activity };
+  PropertyValue();
+  PropertyValue(std::string_view value);
+  PropertyValue(std::string value);
+  PropertyValue(float value,
+                const Unit *unit);
+  PropertyValue(bool value);
+  PropertyValue(const Library *value);
+  PropertyValue(const Cell *value);
+  PropertyValue(const Port *value);
+  PropertyValue(const LibertyLibrary *value);
+  PropertyValue(const LibertyCell *value);
+  PropertyValue(const LibertyPort *value);
+  PropertyValue(const Instance *value);
+  PropertyValue(const Pin *value);
+  PropertyValue(PinSeq *value);
+  PropertyValue(PinSet *value);
+  PropertyValue(const PinSet &value);
+  PropertyValue(const Net *value);
+  PropertyValue(const Clock *value);
+  PropertyValue(ClockSeq *value);
+  PropertyValue(ClockSet *value);
+  PropertyValue(ConstPathSeq *value);
+  PropertyValue(PwrActivity *value);
+  PropertyValue(const PropertyValue &value);
+  PropertyValue(PropertyValue &&value) noexcept;
+  ~PropertyValue();
+  Type type() const { return type_; }
+  const Unit *unit() const { return unit_; }
+
+  std::string to_string(const Network *network) const;
+  const std::string &stringValue() const; // valid for type string
+  float floatValue() const;        // valid for type float
+  bool boolValue() const;          // valid for type bool
+  const LibertyLibrary *libertyLibrary() const { return liberty_library_; }
+  const LibertyCell *libertyCell() const { return liberty_cell_; }
+  const LibertyPort *libertyPort() const { return liberty_port_; }
+  const Library *library() const { return library_; }
+  const Cell *cell() const { return cell_; }
+  const Port *port() const { return port_; }
+  const Instance *instance() const { return inst_; }
+  const Pin *pin() const { return pin_; }
+  PinSeq *pins() const { return pins_; }
+  const Net *net() const { return net_; }
+  const Clock *clock() const { return clk_; }
+  ClockSeq *clocks() const { return clks_; }
+  ConstPathSeq *paths() const { return paths_; }
+  PwrActivity pwrActivity() const { return pwr_activity_; }
+
+  // Copy assignment.
+  PropertyValue &operator=(const PropertyValue &);
+  // Move assignment.
+  PropertyValue &operator=(PropertyValue &&) noexcept;
+
+private:
+  void destroyActive();
+
+  Type type_;
+  union {
+    // Use heap string to simplify initialization/destrucction.
+    std::string *string_;
+    float float_;
+    bool bool_;
+    const Library *library_;
+    const Cell *cell_;
+    const Port *port_;
+    const LibertyLibrary *liberty_library_;
+    const LibertyCell *liberty_cell_;
+    const LibertyPort *liberty_port_;
+    const Instance *inst_;
+    const Pin *pin_;
+    PinSeq *pins_;
+    const Net *net_;
+    const Clock *clk_;
+    ClockSeq *clks_;
+    ConstPathSeq *paths_;
+    PwrActivity pwr_activity_;
+  };
+  const Unit *unit_;
+};
+
+// Key for user-defined property values: the object instance and the
+// property name.
+class PropertyKey
+{
+public:
+  PropertyKey(const void *object,
+              std::string_view property);
+  bool operator<(const PropertyKey &key) const;
+
+private:
+  const void *object_;
+  std::string property_;
+};
+
 class Properties
 {
 public:
@@ -124,6 +237,25 @@ public:
                       const PropertyRegistry<const Net *>::PropertyHandler &handler);
   void defineProperty(std::string_view property,
                       const PropertyRegistry<const Clock *>::PropertyHandler &handler);
+  void defineProperty(std::string_view property,
+                      const PropertyRegistry<const Scene *>::PropertyHandler &handler);
+  void defineProperty(std::string_view property,
+                      const PropertyRegistry<const Mode *>::PropertyHandler &handler);
+
+  // User-defined, per-object mutable properties. defineProperty registers
+  // a property of the given value type ("bool", "float" or "string");
+  // setProperty sets the value on one object. Objects the property was never
+  // set on read back as an empty (none) value. The property is read through
+  // the same registry path as every other property so get_property /
+  // get_* -filter work unchanged.
+  template<class TYPE>
+  void defineProperty(std::string_view object_type,
+                      std::string_view property,
+                      std::string_view value_type);
+  void setProperty(const void *object,
+                   std::string_view object_type,
+                   std::string_view property,
+                   std::string_view value);
 
 protected:
   PropertyValue portSlew(const Port *port,
@@ -149,6 +281,9 @@ protected:
   PropertyValue edgeDelay(Edge *edge,
                           const RiseFall *rf,
                           const MinMax *min_max);
+  PropertyValue::Type propertyType(std::string_view type);
+  PropertyValue coercePropertyValue(PropertyValue::Type type,
+                                    std::string_view value);
 
   PropertyRegistry<const Library*> registry_library_;
   PropertyRegistry<const LibertyLibrary*> registry_liberty_library_;
@@ -160,106 +295,16 @@ protected:
   PropertyRegistry<const Pin*> registry_pin_;
   PropertyRegistry<const Net*> registry_net_;
   PropertyRegistry<const Clock*> registry_clock_;
+  PropertyRegistry<const Scene*> registry_scene_;
+  PropertyRegistry<const Mode*> registry_mode_;
 
-  Sta *sta_;
-};
-
-// Adding a new property type
-//  value union (string values use std::string* so the union stays trivial)
-//  enum Type
-//  constructor
-//  copy constructor switch clause
-//  move constructor switch clause
-//  operator= &  switch clause
-//  operator= && switch clause
-//  StaTcl.i swig %typemap(out) PropertyValue switch clause
+  // Value types of user-defined properties keyed by object type name and
+  // property name.
+  std::map<std::pair<std::string, std::string>, PropertyValue::Type> prop_types_;
+  // User-defined property values.
+  std::map<PropertyKey, PropertyValue> prop_values_;
 
-class PropertyValue
-{
-public:
-  enum class Type { none, string, float_, bool_,
-                    library, cell, port,
-                    liberty_library, liberty_cell, liberty_port,
-                    instance, pin, pins, net,
-                    clk, clks, paths, pwr_activity };
-  PropertyValue();
-  PropertyValue(std::string_view value);
-  PropertyValue(std::string value);
-  PropertyValue(float value,
-                const Unit *unit);
-  PropertyValue(bool value);
-  PropertyValue(const Library *value);
-  PropertyValue(const Cell *value);
-  PropertyValue(const Port *value);
-  PropertyValue(const LibertyLibrary *value);
-  PropertyValue(const LibertyCell *value);
-  PropertyValue(const LibertyPort *value);
-  PropertyValue(const Instance *value);
-  PropertyValue(const Pin *value);
-  PropertyValue(PinSeq *value);
-  PropertyValue(PinSet *value);
-  PropertyValue(const PinSet &value);
-  PropertyValue(const Net *value);
-  PropertyValue(const Clock *value);
-  PropertyValue(ClockSeq *value);
-  PropertyValue(ClockSet *value);
-  PropertyValue(ConstPathSeq *value);
-  PropertyValue(PwrActivity *value);
-  PropertyValue(const PropertyValue &value);
-  PropertyValue(PropertyValue &&value) noexcept;
-  ~PropertyValue();
-  Type type() const { return type_; }
-  const Unit *unit() const { return unit_; }
-
-  std::string to_string(const Network *network) const;
-  const std::string &stringValue() const; // valid for type string
-  float floatValue() const;        // valid for type float
-  bool boolValue() const;          // valid for type bool
-  const LibertyLibrary *libertyLibrary() const { return liberty_library_; }
-  const LibertyCell *libertyCell() const { return liberty_cell_; }
-  const LibertyPort *libertyPort() const { return liberty_port_; }
-  const Library *library() const { return library_; }
-  const Cell *cell() const { return cell_; }
-  const Port *port() const { return port_; }
-  const Instance *instance() const { return inst_; }
-  const Pin *pin() const { return pin_; }
-  PinSeq *pins() const { return pins_; }
-  const Net *net() const { return net_; }
-  const Clock *clock() const { return clk_; }
-  ClockSeq *clocks() const { return clks_; }
-  ConstPathSeq *paths() const { return paths_; }
-  PwrActivity pwrActivity() const { return pwr_activity_; }
-
-  // Copy assignment.
-  PropertyValue &operator=(const PropertyValue &);
-  // Move assignment.
-  PropertyValue &operator=(PropertyValue &&) noexcept;
-
-private:
-  void destroyActive();
-
-  Type type_;
-  union {
-    // Use heap string to simplify initialization/destrucction.
-    std::string *string_;
-    float float_;
-    bool bool_;
-    const Library *library_;
-    const Cell *cell_;
-    const Port *port_;
-    const LibertyLibrary *liberty_library_;
-    const LibertyCell *liberty_cell_;
-    const LibertyPort *liberty_port_;
-    const Instance *inst_;
-    const Pin *pin_;
-    PinSeq *pins_;
-    const Net *net_;
-    const Clock *clk_;
-    ClockSeq *clks_;
-    ConstPathSeq *paths_;
-    PwrActivity pwr_activity_;
-  };
-  const Unit *unit_;
+  Sta *sta_;
 };
 
 } // namespace sta
diff --git a/include/sta/Search.hh b/include/sta/Search.hh
index 539c9895..5661a387 100644
--- a/include/sta/Search.hh
+++ b/include/sta/Search.hh
@@ -286,8 +286,6 @@ public:
                                TagGroupBldr *tag_bldr);
   void postponeLatchDataOutputs(Vertex *vertex);
   void postponeArrivals(Vertex *vertex);
-  void enqueuePendingClkFanouts();
-  void postponeClkFanouts(Vertex *vertex);
   void seedRequired(Vertex *vertex);
   void seedRequiredEnqueueFanin(Vertex *vertex);
   void seedInputDelayArrival(const Pin *pin,
@@ -503,12 +501,12 @@ protected:
                      bool is_segment_start,
                      const MinMax *min_max,
                      Scene *scene);
-  void seedClkVertexArrivals();
-  void findClkArrivals1();
+  void enqueueClkRoots();
+  void enqueueInvalidClks();
 
-  void findAllArrivals(bool thru_latches,
-                       bool clks_only);
+  void findAllArrivals(bool thru_latches);
   void findArrivals1(Level level);
+  void findArrivals2(Level level);
   Tag *mutateTag(Tag *from_tag,
                  const Pin *from_pin,
                  const RiseFall *from_rf,
@@ -646,12 +644,9 @@ protected:
   std::vector<TagIndex> tag_group_free_indices_;
   std::mutex tag_group_lock_;
 
-  // Latches data outputs to queue on the next search pass.
-  VertexSet postponed_arrivals_;
-  std::mutex postponed_arrivals_lock_;
-  // Clock network endpoints where arrival search was suppended by findClkArrivals().
-  VertexSet postponed_clk_endpoints_;
-  std::mutex postponed_clk_endpoints_lock_;
+  // Arrivals to queue on the next search pass.
+  VertexSet pending_arrivals_;
+  std::mutex pending_arrivals_lock_;
 
   VertexSet endpoints_;
   bool endpoints_initialized_{false};
diff --git a/include/sta/Sta.hh b/include/sta/Sta.hh
index 9f9f53ed..99bcba4f 100644
--- a/include/sta/Sta.hh
+++ b/include/sta/Sta.hh
@@ -947,6 +947,11 @@ public:
   // from/thrus/to are owned and deleted by Search.
   // PathEnds in the returned PathEndSeq are owned by Search PathGroups
   // and deleted on next call.
+  //
+  // IMPORTANT: THIS IS NOT THE DROID YOU ARE LOOKING FOR.
+  // This function is specifically designed to support the many options
+  // and results of timing reports. It is NOT a good option to find paths
+  // for optimization.
   PathEndSeq findPathEnds(ExceptionFrom *from,
                           ExceptionThruSeq *thrus,
                           ExceptionTo *to,
diff --git a/sdc/FilterObjects.cc b/sdc/FilterObjects.cc
index 509e48df..eeea29f4 100644
--- a/sdc/FilterObjects.cc
+++ b/sdc/FilterObjects.cc
@@ -42,6 +42,7 @@
 #include "GraphCmp.hh"
 #include "Liberty.hh"
 #include "LibertyClass.hh"
+#include "Mode.hh"
 #include "Network.hh"
 #include "NetworkClass.hh"
 #include "PathEnd.hh"
@@ -497,6 +498,30 @@ filterClocks(std::string_view filter_expression,
                                    }, sta);
 }
 
+SceneSeq
+filterScenes(std::string_view filter_expression,
+             SceneSeq *scenes,
+             Sta *sta)
+{
+  return filterObjects<Scene>(filter_expression, scenes,
+                              [] (const Scene *scene1,
+                                  const Scene *scene2) {
+                                return scene1->name() < scene2->name();
+                              }, sta);
+}
+
+ModeSeq
+filterModes(std::string_view filter_expression,
+            ModeSeq *modes,
+            Sta *sta)
+{
+  return filterObjects<Mode>(filter_expression, modes,
+                             [] (const Mode *mode1,
+                                 const Mode *mode2) {
+                               return mode1->name() < mode2->name();
+                             }, sta);
+}
+
 LibertyCellSeq
 filterLibCells(std::string_view filter_expression,
                LibertyCellSeq *cells,
diff --git a/sdc/Sdc.i b/sdc/Sdc.i
index 4b3050b0..3ac13d81 100644
--- a/sdc/Sdc.i
+++ b/sdc/Sdc.i
@@ -1531,6 +1531,22 @@ filter_clocks(const char *filter_expression,
   return filterClocks(filter_expression, clocks, sta);
 }
 
+SceneSeq
+filter_scenes(const char *filter_expression,
+              SceneSeq *scenes)
+{
+  sta::Sta *sta = Sta::sta();
+  return filterScenes(filter_expression, scenes, sta);
+}
+
+ModeSeq
+filter_modes(const char *filter_expression,
+             ModeSeq *modes)
+{
+  sta::Sta *sta = Sta::sta();
+  return filterModes(filter_expression, modes, sta);
+}
+
 LibertyCellSeq
 filter_lib_cells(const char *filter_expression,
                  LibertyCellSeq *cells)
diff --git a/search/Bfs.cc b/search/Bfs.cc
index 1768ae43..50c8252c 100644
--- a/search/Bfs.cc
+++ b/search/Bfs.cc
@@ -71,13 +71,21 @@ BfsIterator::ensureSize()
 
 void
 BfsIterator::clear()
+{
+  clear([] (Vertex *) {});
+}
+
+void
+BfsIterator::clear(const VertexFn &fn)
 {
   Level level = first_level_;
   while (levelLessOrEqual(level, last_level_)) {
     VertexSeq &level_vertices = queue_[level];
     for (Vertex *vertex : level_vertices) {
-      if (vertex)
+      if (vertex) {
         vertex->setBfsInQueue(bfs_index_, false);
+        fn(vertex);
+      }
     }
     level_vertices.clear();
     incrLevel(level);
@@ -116,19 +124,6 @@ BfsIterator::empty() const
   return levelLess(last_level_, first_level_);
 }
 
-void
-BfsIterator::enqueueAdjacentVertices(Vertex *vertex)
-{
-  enqueueAdjacentVertices(vertex, search_pred_);
-}
-
-void
-BfsIterator::enqueueAdjacentVertices(Vertex *vertex,
-                                     const Mode *mode)
-{
-  enqueueAdjacentVertices(vertex, search_pred_, mode);
-}
-
 int
 BfsIterator::visit(Level to_level,
                    VertexVisitor *visitor)
@@ -218,50 +213,6 @@ BfsIterator::visitParallel(Level to_level,
   return visit_count;
 }
 
-bool
-BfsIterator::hasNext()
-{
-  return hasNext(last_level_);
-}
-
-bool
-BfsIterator::hasNext(Level to_level)
-{
-  findNext(to_level);
-  return levelLessOrEqual(first_level_, last_level_)
-      && !queue_[first_level_].empty();
-}
-
-Vertex *
-BfsIterator::next()
-{
-  VertexSeq &level_vertices = queue_[first_level_];
-  Vertex *vertex = level_vertices.back();
-  level_vertices.pop_back();
-  vertex->setBfsInQueue(bfs_index_, false);
-  return vertex;
-}
-
-void
-BfsIterator::findNext(Level to_level)
-{
-  while (levelLessOrEqual(first_level_, last_level_)
-         && levelLessOrEqual(first_level_, to_level)) {
-    VertexSeq &level_vertices = queue_[first_level_];
-    // Skip null entries from deleted vertices.
-    while (!level_vertices.empty()) {
-      Vertex *vertex = level_vertices.back();
-      if (vertex == nullptr)
-        level_vertices.pop_back();
-      else {
-        checkLevel(vertex, first_level_);
-        return;
-      }
-    }
-    incrLevel(first_level_);
-  }
-}
-
 void
 BfsIterator::enqueue(Vertex *vertex)
 {
@@ -341,6 +292,52 @@ BfsIterator::remove(Vertex *vertex)
 
 ////////////////////////////////////////////////////////////////
 
+bool
+BfsIterator::hasNext()
+{
+  return hasNext(last_level_);
+}
+
+bool
+BfsIterator::hasNext(Level to_level)
+{
+  findNext(to_level);
+  return levelLessOrEqual(first_level_, last_level_)
+      && !queue_[first_level_].empty();
+}
+
+Vertex *
+BfsIterator::next()
+{
+  VertexSeq &level_vertices = queue_[first_level_];
+  Vertex *vertex = level_vertices.back();
+  level_vertices.pop_back();
+  vertex->setBfsInQueue(bfs_index_, false);
+  return vertex;
+}
+
+void
+BfsIterator::findNext(Level to_level)
+{
+  while (levelLessOrEqual(first_level_, last_level_)
+         && levelLessOrEqual(first_level_, to_level)) {
+    VertexSeq &level_vertices = queue_[first_level_];
+    // Skip null entries from deleted vertices.
+    while (!level_vertices.empty()) {
+      Vertex *vertex = level_vertices.back();
+      if (vertex == nullptr)
+        level_vertices.pop_back();
+      else {
+        checkLevel(vertex, first_level_);
+        return;
+      }
+    }
+    incrLevel(first_level_);
+  }
+}
+
+////////////////////////////////////////////////////////////////
+
 BfsFwdIterator::BfsFwdIterator(BfsIndex bfs_index,
                                SearchPred *search_pred,
                                StaState *sta) :
@@ -376,15 +373,46 @@ BfsFwdIterator::levelLess(Level level1,
 }
 
 void
-BfsFwdIterator::enqueueAdjacentVertices(Vertex *vertex,
-                                        SearchPred *search_pred)
+BfsFwdIterator::enqueueFanout(Vertex *vertex)
 {
-  if (search_pred->searchFrom(vertex)) {
+  if (search_pred_->searchFrom(vertex)) {
     VertexOutEdgeIterator edge_iter(vertex, graph_);
     while (edge_iter.hasNext()) {
       Edge *edge = edge_iter.next();
       Vertex *to_vertex = edge->to(graph_);
-      if (search_pred->searchThru(edge) && search_pred->searchTo(to_vertex))
+      if (search_pred_->searchThru(edge)
+          && search_pred_->searchTo(to_vertex))
+        enqueue(to_vertex);
+    }
+  }
+}
+
+void
+BfsFwdIterator::enqueueFanout(Vertex *vertex,
+                              const Mode *mode)
+{
+  if (search_pred_->searchFrom(vertex, mode)) {
+    VertexOutEdgeIterator edge_iter(vertex, graph_);
+    while (edge_iter.hasNext()) {
+      Edge *edge = edge_iter.next();
+      Vertex *to_vertex = edge->to(graph_);
+      if (search_pred_->searchThru(edge, mode)
+          && search_pred_->searchTo(to_vertex, mode))
+        enqueue(to_vertex);
+    }
+  }
+}
+
+void
+BfsFwdIterator::enqueueAdjacentVertices(Vertex *vertex)
+{
+  if (search_pred_->searchFrom(vertex)) {
+    VertexOutEdgeIterator edge_iter(vertex, graph_);
+    while (edge_iter.hasNext()) {
+      Edge *edge = edge_iter.next();
+      Vertex *to_vertex = edge->to(graph_);
+      if (search_pred_->searchThru(edge)
+          && search_pred_->searchTo(to_vertex))
         enqueue(to_vertex);
     }
   }
@@ -392,16 +420,15 @@ BfsFwdIterator::enqueueAdjacentVertices(Vertex *vertex,
 
 void
 BfsFwdIterator::enqueueAdjacentVertices(Vertex *vertex,
-                                        SearchPred *search_pred,
                                         const Mode *mode)
 {
-  if (search_pred->searchFrom(vertex, mode)) {
+  if (search_pred_->searchFrom(vertex, mode)) {
     VertexOutEdgeIterator edge_iter(vertex, graph_);
     while (edge_iter.hasNext()) {
       Edge *edge = edge_iter.next();
       Vertex *to_vertex = edge->to(graph_);
-      if (search_pred->searchThru(edge, mode)
-          && search_pred->searchTo(to_vertex, mode))
+      if (search_pred_->searchThru(edge, mode)
+          && search_pred_->searchTo(to_vertex, mode))
         enqueue(to_vertex);
     }
   }
@@ -444,15 +471,15 @@ BfsBkwdIterator::levelLess(Level level1,
 }
 
 void
-BfsBkwdIterator::enqueueAdjacentVertices(Vertex *vertex,
-                                         SearchPred *search_pred)
+BfsBkwdIterator::enqueueAdjacentVertices(Vertex *vertex)
 {
-  if (search_pred->searchTo(vertex)) {
+  if (search_pred_->searchTo(vertex)) {
     VertexInEdgeIterator edge_iter(vertex, graph_);
     while (edge_iter.hasNext()) {
       Edge *edge = edge_iter.next();
       Vertex *from_vertex = edge->from(graph_);
-      if (search_pred->searchFrom(from_vertex) && search_pred->searchThru(edge))
+      if (search_pred_->searchFrom(from_vertex)
+          && search_pred_->searchThru(edge))
         enqueue(from_vertex);
     }
   }
@@ -460,16 +487,46 @@ BfsBkwdIterator::enqueueAdjacentVertices(Vertex *vertex,
 
 void
 BfsBkwdIterator::enqueueAdjacentVertices(Vertex *vertex,
-                                         SearchPred *search_pred,
                                          const Mode *mode)
 {
-  if (search_pred->searchTo(vertex, mode)) {
+  if (search_pred_->searchTo(vertex, mode)) {
+    VertexInEdgeIterator edge_iter(vertex, graph_);
+    while (edge_iter.hasNext()) {
+      Edge *edge = edge_iter.next();
+      Vertex *from_vertex = edge->from(graph_);
+      if (search_pred_->searchFrom(from_vertex, mode)
+          && search_pred_->searchThru(edge, mode))
+        enqueue(from_vertex);
+    }
+  }
+}
+
+void
+BfsBkwdIterator::enqueueFanin(Vertex *vertex)
+{
+  if (search_pred_->searchTo(vertex)) {
+    VertexInEdgeIterator edge_iter(vertex, graph_);
+    while (edge_iter.hasNext()) {
+      Edge *edge = edge_iter.next();
+      Vertex *from_vertex = edge->from(graph_);
+      if (search_pred_->searchFrom(from_vertex)
+          && search_pred_->searchThru(edge))
+        enqueue(from_vertex);
+    }
+  }
+}
+
+void
+BfsBkwdIterator::enqueueFanin(Vertex *vertex,
+                              const Mode *mode)
+{
+  if (search_pred_->searchTo(vertex, mode)) {
     VertexInEdgeIterator edge_iter(vertex, graph_);
     while (edge_iter.hasNext()) {
       Edge *edge = edge_iter.next();
       Vertex *from_vertex = edge->from(graph_);
-      if (search_pred->searchFrom(from_vertex, mode)
-          && search_pred->searchThru(edge, mode))
+      if (search_pred_->searchFrom(from_vertex, mode)
+          && search_pred_->searchThru(edge, mode))
         enqueue(from_vertex);
     }
   }
diff --git a/search/ClkNetwork.cc b/search/ClkNetwork.cc
index 93a29496..991a1821 100644
--- a/search/ClkNetwork.cc
+++ b/search/ClkNetwork.cc
@@ -24,7 +24,8 @@
 
 #include "ClkNetwork.hh"
 
-#include "Bfs.hh"
+#include <queue>
+
 #include "Debug.hh"
 #include "Graph.hh"
 #include "Mode.hh"
@@ -127,7 +128,6 @@ ClkNetwork::findClkPins(bool ideal_only,
 {
   const Sdc *sdc = mode_->sdc();
   ClkSearchPred srch_pred(this);
-  BfsFwdIterator bfs(BfsIndex::other, &srch_pred, this);
   for (Clock *clk : sdc->clocks()) {
     if (!ideal_only
         || !clk->isPropagated()) {
@@ -136,25 +136,39 @@ ClkNetwork::findClkPins(bool ideal_only,
         clk_pins = new PinSet(network_);
         clk_pins_map_[clk] = clk_pins;
       }
+      std::queue<Vertex *> queue;
+      VertexSet visited = makeVertexSet(this);
+      auto enqueue = [&queue, &visited] (Vertex *vertex) {
+        if (vertex && !visited.contains(vertex)) {
+          visited.insert(vertex);
+          queue.push(vertex);
+        }
+      };
       for (const Pin *pin : clk->leafPins()) {
         if (!ideal_only
             || !sdc->isPropagatedClock(pin)) {
           Vertex *vertex, *bidirect_drvr_vertex;
           graph_->pinVertices(pin, vertex, bidirect_drvr_vertex);
-          bfs.enqueue(vertex);
-          if (bidirect_drvr_vertex)
-            bfs.enqueue(bidirect_drvr_vertex);
+          enqueue(vertex);
+          enqueue(bidirect_drvr_vertex);
         }
       }
-      while (bfs.hasNext()) {
-        Vertex *vertex = bfs.next();
+      while (!queue.empty()) {
+        Vertex *vertex = queue.front();
+        queue.pop();
         const Pin *pin = vertex->pin();
         if (!ideal_only
             || !sdc->isPropagatedClock(pin)) {
           clk_pins->insert(pin);
           ClockSet &pin_clks = pin_clks_map[pin];
           pin_clks.insert(clk);
-          bfs.enqueueAdjacentVertices(vertex);
+          graph_->visitFanouts(vertex, &srch_pred,
+                               [&queue, &visited] (Vertex *fanout) {
+                                 if (!visited.contains(fanout)) {
+                                   visited.insert(fanout);
+                                   queue.push(fanout);
+                                 }
+                               });
         }
       }
     }
diff --git a/search/Genclks.cc b/search/Genclks.cc
index 7b16a51f..2aad7074 100644
--- a/search/Genclks.cc
+++ b/search/Genclks.cc
@@ -271,7 +271,6 @@ Genclks::ensureMaster(Clock *gclk,
       // Search backward from generated clock source pin to a clock pin.
       GenClkMasterSearchPred srch_pred(this);
       VertexQueue master_queue;
-      VertexSet visited = makeVertexSet(this);
       VertexSet src_vertices = makeVertexSet(this);
       gclk->srcPinVertices(src_vertices, network_, graph_);
       for (Vertex *vertex : src_vertices)
@@ -279,28 +278,25 @@ Genclks::ensureMaster(Clock *gclk,
       while (!master_queue.empty()) {
         Vertex *vertex = master_queue.front();
         master_queue.pop();
-        if (!visited.contains(vertex)) {
-          visited.insert(vertex);
-          Pin *pin = vertex->pin();
-          if (sdc->isLeafPinClock(pin)) {
-            ClockSet *master_clks = sdc->findLeafPinClocks(pin);
-            if (master_clks) {
-              ClockSet::iterator master_iter = master_clks->begin();
-              if (master_iter != master_clks->end()) {
-                master_clk = *master_iter++;
-                // Master source pin can actually be a clock source pin.
-                if (master_clk != gclk) {
-                  gclk->setInferedMasterClk(master_clk);
-                  debugPrint(debug_, "genclk", 2, " {} master clk {}", gclk->name(),
-                             master_clk->name());
-                  master_clk_count++;
-                  break;
-                }
+        Pin *pin = vertex->pin();
+        if (sdc->isLeafPinClock(pin)) {
+          ClockSet *master_clks = sdc->findLeafPinClocks(pin);
+          if (master_clks) {
+            ClockSet::iterator master_iter = master_clks->begin();
+            if (master_iter != master_clks->end()) {
+              master_clk = *master_iter++;
+              // Master source pin can actually be a clock source pin.
+              if (master_clk != gclk) {
+                gclk->setInferedMasterClk(master_clk);
+                debugPrint(debug_, "genclk", 2, " {} master clk {}", gclk->name(),
+                           master_clk->name());
+                master_clk_count++;
+                break;
               }
             }
           }
-          enqueueFanin(vertex, master_queue, srch_pred);
         }
+        enqueueFanin(vertex, master_queue, srch_pred);
       }
     }
     if (master_clk_count > 1)
diff --git a/search/Property.cc b/search/Property.cc
index 6ecd9ab7..ee3ddc11 100644
--- a/search/Property.cc
+++ b/search/Property.cc
@@ -26,6 +26,7 @@
 
 #include <algorithm>
 #include <string>
+#include <tuple>
 #include <utility>
 
 #include "Clock.hh"
@@ -1205,7 +1206,9 @@ Properties::getProperty(const Scene *scene,
       || property == "full_name")
     return PropertyValue(scene->name());
   else
-    throw PropertyUnknown("scene", property);
+    // Unknown properties throw PropertyUnknown; a user-defined property
+    // never set on this scene returns a none value.
+    return registry_scene_.getProperty(scene, property, "scene", sta_);
 }
 
 ////////////////////////////////////////////////////////////////
@@ -1218,7 +1221,9 @@ Properties::getProperty(const Mode *mode,
       || property == "full_name")
     return PropertyValue(mode->name());
   else
-    throw PropertyUnknown("mode", property);
+    // Unknown properties throw PropertyUnknown; a user-defined property
+    // never set on this mode returns a none value.
+    return registry_mode_.getProperty(mode, property, "mode", sta_);
 }
 
 ////////////////////////////////////////////////////////////////
@@ -1360,6 +1365,119 @@ Properties::defineProperty(std::string_view property,
   registry_clock_.defineProperty(property, handler);
 }
 
+void
+Properties::defineProperty(std::string_view property,
+                           const PropertyRegistry<const Scene *>::PropertyHandler &handler)
+{
+  registry_scene_.defineProperty(property, handler);
+}
+
+void
+Properties::defineProperty(std::string_view property,
+                           const PropertyRegistry<const Mode *>::PropertyHandler &handler)
+{
+  registry_mode_.defineProperty(property, handler);
+}
+
+////////////////////////////////////////////////////////////////
+
+// Value type from the define_property -type argument.
+PropertyValue::Type
+Properties::propertyType(std::string_view type)
+{
+  if (type == "bool" || type == "boolean")
+    return PropertyValue::Type::bool_;
+  else if (type == "float" || type == "double" || type == "number")
+    return PropertyValue::Type::float_;
+  else if (type == "string")
+    return PropertyValue::Type::string;
+  else
+    sta_->report()->error(2210, "unknown property type '{}' (use bool, float or string).",
+                          type);
+  return PropertyValue::Type::none;
+}
+
+PropertyValue
+Properties::coercePropertyValue(PropertyValue::Type type,
+                                std::string_view value)
+{
+  switch (type) {
+  case PropertyValue::Type::bool_:
+    if (stringEqual(value, "true") || value == "1")
+      return PropertyValue(true);
+    if (stringEqual(value, "false") || value == "0")
+      return PropertyValue(false);
+    sta_->report()->error(2212, "'{}' is not a bool property value.", value);
+    return PropertyValue();
+  case PropertyValue::Type::float_: {
+    auto [number, valid] = stringFloat(std::string(value));
+    if (!valid)
+      sta_->report()->error(2215, "'{}' is not a float property value.", value);
+    return PropertyValue(number, sta_->units()->scalarUnit());
+  }
+  default:
+    return PropertyValue(std::string(value));
+  }
+}
+
+PropertyKey::PropertyKey(const void *object,
+                         std::string_view property) :
+  object_(object),
+  property_(property)
+{
+}
+
+bool
+PropertyKey::operator<(const PropertyKey &key) const
+{
+  return std::tie(object_, property_)
+    < std::tie(key.object_, key.property_);
+}
+
+template<class TYPE>
+void
+Properties::defineProperty(std::string_view object_type,
+                           std::string_view property,
+                           std::string_view value_type)
+{
+  prop_types_[{std::string(object_type), std::string(property)}] =
+    propertyType(value_type);
+  std::string name(property);
+  typename PropertyRegistry<const TYPE *>::PropertyHandler handler =
+    [this, name] (const TYPE *object,
+                  Sta *) -> PropertyValue {
+      auto value_iter = prop_values_.find(PropertyKey(object, name));
+      if (value_iter != prop_values_.end())
+        return value_iter->second;
+      // Never set on this object.
+      return PropertyValue();
+    };
+  defineProperty(property, handler);
+}
+
+// Object types the tcl interface exposes user properties on.
+template void Properties::defineProperty<Scene>(std::string_view,
+                                                std::string_view,
+                                                std::string_view);
+template void Properties::defineProperty<Mode>(std::string_view,
+                                               std::string_view,
+                                               std::string_view);
+
+void
+Properties::setProperty(const void *object,
+                        std::string_view object_type,
+                        std::string_view property,
+                        std::string_view value)
+{
+  auto type_iter = prop_types_.find({std::string(object_type),
+                                     std::string(property)});
+  if (type_iter == prop_types_.end())
+    sta_->report()->error(2211, "{} property '{}' is not defined.",
+                          object_type, property);
+  prop_values_[PropertyKey(object, property)] =
+    coercePropertyValue(type_iter->second, value);
+}
+
 ////////////////////////////////////////////////////////////////
 
 template<class TYPE>
diff --git a/search/Property.i b/search/Property.i
index 2002f901..c282f5fb 100644
--- a/search/Property.i
+++ b/search/Property.i
@@ -25,6 +25,7 @@
 %{
 
 #include "Property.hh"
+#include "Report.hh"
 #include "Sta.hh"
 
 using namespace sta;
@@ -137,6 +138,39 @@ mode_property(Mode *mode,
   return properties.getProperty(mode, property);
 }
 
+void
+define_property_cmd(const char *object_type,
+                    const char *property,
+                    const char *type)
+{
+  Properties &properties = Sta::sta()->properties();
+  std::string_view object_type_view(object_type);
+  if (object_type_view == "scene")
+    properties.defineProperty<Scene>(object_type, property, type);
+  else if (object_type_view == "mode")
+    properties.defineProperty<Mode>(object_type, property, type);
+  else
+    Sta::sta()->report()->error(2209, "define_property -object_type {} not supported.",
+                                object_type);
+}
+
+void
+set_property_cmd(void *object,
+                 const char *object_type,
+                 const char *property,
+                 const char *value)
+{
+  Properties &properties = Sta::sta()->properties();
+  std::string_view object_type_view(object_type);
+  if (object_type_view == "Scene")
+    properties.setProperty(object, "scene", property, value);
+  else if (object_type_view == "Mode")
+    properties.setProperty(object, "mode", property, value);
+  else
+    Sta::sta()->report()->error(2214, "set_property unsupported object type {}.",
+                                object_type);
+}
+
 PropertyValue
 path_end_property(PathEnd *end,
                   const char *property)
diff --git a/search/Search.cc b/search/Search.cc
index 879c1247..69be1f7f 100644
--- a/search/Search.cc
+++ b/search/Search.cc
@@ -30,6 +30,7 @@
 
 #include "Bfs.hh"
 #include "ClkInfo.hh"
+#include "ClkNetwork.hh"
 #include "Clock.hh"
 #include "ContainerHelpers.hh"
 #include "Crpr.hh"
@@ -95,6 +96,8 @@ EvalPred::searchThru(Edge *edge,
 {
   const TimingRole *role = edge->role();
   return SearchPred0::searchThru(edge, mode)
+    && (sta_->variables()->dynamicLoopBreaking()
+        || !edge->isDisabledLoop())
     && (search_thru_latches_
         || role->isLatchDtoQ()
         || sta_->latches()->latchDtoQState(edge, mode) == LatchEnableState::open);
@@ -263,8 +266,7 @@ Search::Search(StaState *sta) :
   tag_group_capacity_(tag_capacity_),
   tag_groups_(new TagGroup *[tag_group_capacity_]),
   tag_group_set_(new TagGroupSet(tag_group_capacity_)),
-  postponed_arrivals_(makeVertexSet(this)),
-  postponed_clk_endpoints_(makeVertexSet(this)),
+  pending_arrivals_(makeVertexSet(this)),
   endpoints_(makeVertexSet(this)),
   invalid_endpoints_(makeVertexSet(this)),
 
@@ -328,8 +330,7 @@ Search::clear()
   deletePathGroups();
   deletePaths();
   deleteTags();
-  postponed_arrivals_.clear();
-  postponed_clk_endpoints_.clear();
+  pending_arrivals_.clear();
   deleteFilter();
   found_downstream_clk_pins_ = false;
 }
@@ -546,7 +547,7 @@ Search::findFilteredArrivals(ExceptionFrom *from,
     // These cases do not require filtered arrivals.
     //  -from clocks
     //  -to
-    findAllArrivals(thru_latches, false);
+    findAllArrivals(thru_latches);
 }
 
 // From/thrus/to are used to make a filter exception.  If the last
@@ -639,32 +640,36 @@ Search::deleteFilterClkInfos()
 void
 Search::findFilteredArrivals(bool thru_latches)
 {
+  // Search always_to_endpoint to search from exisiting arrivals at
+  // fanin startpoints to reach -thru/-to endpoints.
+  arrival_visitor_->init(true, false, eval_pred_);
+  arrival_iter_->ensureSize();
+
   filtered_arrivals_.clear();
   findArrivalsSeed();
   seedFilterStarts();
+
   Level max_level = levelize_->maxLevel();
-  // Search always_to_endpoint to search from exisiting arrivals at
-  // fanin startpoints to reach -thru/-to endpoints.
-  arrival_visitor_->init(true, false, eval_pred_);
-  enqueuePendingClkFanouts();
-  bool have_pending_latch_outputs = false;
-  // Iterate until data arrivals at all latches stop changing.
+  bool have_pending_arrivals = false;
   for (int pass = 1;
-       pass == 1 || (thru_latches && have_pending_latch_outputs);
+       pass == 1 || (thru_latches && have_pending_arrivals);
        pass++) {
     debugPrint(debug_, "search", 1, "find arrivals pass {}", pass);
 
     int arrival_count = arrival_iter_->visitParallel(max_level, arrival_visitor_);
     debugPrint(debug_, "search", 1, "found {} arrivals", arrival_count);
 
-    have_pending_latch_outputs = !postponed_arrivals_.empty();
-    for (Vertex *latch_output : postponed_arrivals_)
-      arrival_visitor_->visit(latch_output, true);
-    postponed_arrivals_.clear();
+    // Latch D->Q and disabled loop edges have level discontinuities so their
+    // eval. For latches the data path crpr clk path may be evaled in another
+    // thread at the same time the latch D->Q edge.
+    // Disabled loop edges propagate pending loop paths here.
+    have_pending_arrivals = !pending_arrivals_.empty();
+    for (Vertex *vertex : pending_arrivals_)
+      arrival_visitor_->visit(vertex, true);
+    pending_arrivals_.clear();
 
     deleteTagsPrev();
   }
-  arrivals_exist_ = true;
 }
 
 // Delete stale tag arrarys.
@@ -860,14 +865,13 @@ void
 Search::levelsChangedBefore()
 {
   if (arrivals_exist_) {
-    while (arrival_iter_->hasNext()) {
-      Vertex *vertex = arrival_iter_->next();
+    arrival_iter_->clear([this] (Vertex *vertex) {
       arrivalInvalid(vertex);
-    }
-    while (required_iter_->hasNext()) {
-      Vertex *vertex = required_iter_->next();
+    });
+
+    required_iter_->clear([this] (Vertex *vertex) {
       requiredInvalid(vertex);
-    }
+    });
   }
 }
 
@@ -939,11 +943,16 @@ Search::requiredInvalid(Vertex *vertex)
 void
 Search::findClkArrivals()
 {
-  findAllArrivals(false, true);
+  debugPrint(debug_, "search", 1, "find clk arrivals");
+  arrival_visitor_->init(false, true, eval_pred_);
+  arrival_iter_->ensureSize();
+  enqueueClkRoots();
+  enqueueInvalidClks();
+  findArrivals2(levelize_->maxLevel());
 }
 
 void
-Search::seedClkVertexArrivals()
+Search::enqueueClkRoots()
 {
   PinSet clk_pins(network_);
   findClkVertexPins(clk_pins);
@@ -954,6 +963,32 @@ Search::seedClkVertexArrivals()
     if (bidirect_drvr_vertex)
       arrival_iter_->enqueue(bidirect_drvr_vertex);
   }
+  arrivals_exist_ = true;
+}
+
+void
+Search::enqueueInvalidClks()
+{
+  if (!invalid_arrivals_.empty()) {
+    for (Mode *mode : modes_)
+      mode->clkNetwork()->ensureClkNetwork();
+    for (auto itr = invalid_arrivals_.begin(); itr != invalid_arrivals_.end();) {
+      Vertex *vertex = *itr;
+      bool is_clk = false;
+      for (Mode *mode : modes_) {
+        if (mode->clkNetwork()->isClock(vertex)) {
+          is_clk = true;
+          break;
+        }
+      }
+      if (is_clk) {
+        arrival_iter_->enqueue(vertex);
+        itr = invalid_arrivals_.erase(itr);
+      }
+      else
+        itr++;
+    }
+  }
 }
 
 Arrival
@@ -980,49 +1015,29 @@ Search::clockInsertion(const Clock *clk,
 void
 Search::findAllArrivals()
 {
-  findAllArrivals(true, false);
+  findAllArrivals(true);
 }
 
 void
-Search::findAllArrivals(bool thru_latches,
-                        bool clks_only)
+Search::findAllArrivals(bool thru_latches)
 {
-  if (!clks_only)
-    enqueuePendingClkFanouts();
-  arrival_visitor_->init(false, clks_only, eval_pred_);
-  bool have_pending_latch_outputs = false;
+  arrival_visitor_->init(false, false, eval_pred_);
+  arrival_iter_->ensureSize();
+
+  bool have_pending_arrivals = false;
   // Iterate until data arrivals at all latches stop changing.
   for (int pass = 1;
-       pass == 1 || (thru_latches && have_pending_latch_outputs);
+       pass == 1 || (thru_latches && have_pending_arrivals);
        pass++) {
     debugPrint(debug_, "search", 1, "find arrivals pass {}", pass);
 
     findArrivals1(levelize_->maxLevel());
 
-    have_pending_latch_outputs = !postponed_arrivals_.empty();
-    for (Vertex *latch_output : postponed_arrivals_)
-      arrival_visitor_->visit(latch_output, true);
-    postponed_arrivals_.clear();
-  }
-}
-
-// Pick up where the search stopped at the clock network boundary.
-void
-Search::enqueuePendingClkFanouts()
-{
-  for (Vertex *vertex : postponed_clk_endpoints_) {
-    debugPrint(debug_, "search", 2, "enqueue clk fanout {}",
-               vertex->to_string(this));
-    arrival_iter_->enqueueAdjacentVertices(vertex, search_adj_);
+    have_pending_arrivals = !pending_arrivals_.empty();
+    for (Vertex *vertex : pending_arrivals_)
+      arrival_visitor_->visit(vertex, true);
+    pending_arrivals_.clear();
   }
-  postponed_clk_endpoints_.clear();
-}
-
-void
-Search::postponeClkFanouts(Vertex *vertex)
-{
-  LockGuard lock(postponed_clk_endpoints_lock_);
-  postponed_clk_endpoints_.insert(vertex);
 }
 
 void
@@ -1035,6 +1050,7 @@ void
 Search::findArrivals(Level level)
 {
   arrival_visitor_->init(false, false, eval_pred_);
+  arrival_iter_->ensureSize();
   findArrivals1(level);
 }
 
@@ -1043,13 +1059,19 @@ Search::findArrivals1(Level level)
 {
   debugPrint(debug_, "search", 1, "find arrivals to level {}", level);
   findArrivalsSeed();
+  findArrivals2(level);
+}
+
+// Caller seeds arrival_iter_.
+void
+Search::findArrivals2(Level level)
+{
   Stats stats(debug_, report_);
   int arrival_count = arrival_iter_->visitParallel(level, arrival_visitor_);
   deleteTagsPrev();
   if (arrival_count > 0)
     deleteUnusedTagGroups();
   stats.report("Find arrivals");
-  arrivals_exist_ = true;
   debugPrint(debug_, "search", 1, "found {} arrivals", arrival_count);
 }
 
@@ -1059,15 +1081,9 @@ Search::findArrivalsSeed()
   if (!arrivals_seeded_) {
     for (const Mode *mode : modes_)
       mode->genclks()->ensureInsertionDelays();
-    arrival_iter_->clear();
-    required_iter_->clear();
     seedArrivals();
     arrivals_seeded_ = true;
   }
-  else {
-    arrival_iter_->ensureSize();
-    required_iter_->ensureSize();
-  }
   seedInvalidArrivals();
 }
 
@@ -1173,22 +1189,18 @@ ArrivalVisitor::visit(Vertex *vertex,
     search_->postponeLatchDataOutputs(vertex);
 
   if ((always_to_endpoints_ || arrivals_changed)) {
-    if (clks_only_ && vertex->isRegClk()) {
-      debugPrint(debug_, "search", 3, "postponing clk fanout");
-      search_->postponeClkFanouts(vertex);
-    }
-    else {
-      graph_->visitFanoutEdges(vertex, search_adj_,
-                               [this] (Edge *edge,
-                                       Vertex *fanout) {
-                                 if (edge->isDisabledLoop()) {
-                                   if (hasPendingLoopPaths(edge))
-                                     search_->postponeArrivals(fanout);
-                                 }
-                                 else
-                                   search_->arrivalIterator()->enqueue(fanout);
-                               });
-    }
+    graph_->visitFanoutEdges(vertex, search_adj_,
+                             [this, vertex] (Edge *edge,
+                                             Vertex *fanout) {
+                               if (edge->isDisabledLoop()) {
+                                 if (hasPendingLoopPaths(edge))
+                                   search_->postponeArrivals(fanout);
+                               }
+                               else if (clks_only_ && vertex->isRegClk())
+                                 search_->arrivalInvalid(fanout);
+                               else
+                                 search_->arrivalIterator()->enqueue(fanout);
+                             });
   }
   if (arrivals_changed) {
     debugPrint(debug_, "search", 4, "arrivals changed");
@@ -1425,8 +1437,8 @@ Search::postponeLatchDataOutputs(Vertex *latch_data)
     Edge *edge = edge_iter.next();
     if (edge->role() == TimingRole::latchDtoQ()) {
       Vertex *out_vertex = edge->to(graph_);
-      LockGuard lock(postponed_arrivals_lock_);
-      postponed_arrivals_.insert(out_vertex);
+      LockGuard lock(pending_arrivals_lock_);
+      pending_arrivals_.insert(out_vertex);
     }
   }
 }
@@ -1434,8 +1446,8 @@ Search::postponeLatchDataOutputs(Vertex *latch_data)
 void
 Search::postponeArrivals(Vertex *vertex)
 {
-  LockGuard lock(postponed_arrivals_lock_);
-  postponed_arrivals_.insert(vertex);
+  LockGuard lock(pending_arrivals_lock_);
+  pending_arrivals_.insert(vertex);
 }
 
 void
@@ -1448,6 +1460,7 @@ Search::seedArrivals()
 
   for (Vertex *vertex : vertices)
     arrival_iter_->enqueue(vertex);
+  arrivals_exist_ = true;
 }
 
 void
@@ -2764,14 +2777,14 @@ Search::reportArrivals(Vertex *vertex,
     for (const Path *path : paths) {
       const Tag *tag = path->tag(this);
       const RiseFall *rf = tag->transition();
-      bool report_prev = false;
+      bool report_prev = true;
       std::string prev_str;
       if (report_prev) {
         Path *prev_path = path->prevPath();
         if (prev_path) {
           const Edge *prev_edge = path->prevEdge(this);
           TimingArc *arc = path->prevArc(this);
-          prev_str = sta::format("prev {} {} {} -> {} {}",
+          prev_str = sta::format(" prev {} {} {} -> {} {}",
                                  prev_path->to_string(this),
                                  prev_edge->from(graph_)->to_string(this),
                                  arc->fromEdge()->to_string(),
@@ -2779,13 +2792,14 @@ Search::reportArrivals(Vertex *vertex,
                                  arc->toEdge()->to_string());
         }
         else
-          prev_str = "prev NULL";
+          prev_str = " prev NULL";
       }
       report_->report(" {} {} {} / {} {}{}", rf->shortName(),
                       path->minMax(this)->to_string(),
                       delayAsString(path->arrival(), digits, this),
                       delayAsString(path->required(), digits, this),
-                      tag->to_string(report_tag_index, false, this), prev_str);
+                      tag->to_string(report_tag_index, false, this),
+                      prev_str);
     }
   }
   else
@@ -3146,6 +3160,7 @@ Search::findRequireds(Level level)
   Stats stats(debug_, report_);
   debugPrint(debug_, "search", 1, "find requireds to level {}", level);
   RequiredVisitor req_visitor(this);
+  required_iter_->ensureSize();
   if (!requireds_seeded_)
     seedRequireds();
   seedInvalidRequireds();
@@ -3334,8 +3349,9 @@ Search::seedRequired(Vertex *vertex)
   required_cmp.requiredsInit(vertex, this);
   visit_path_ends_->visitPathEnds(vertex, &seeder);
   // Enqueue fanin vertices for back-propagating required times.
+  required_iter_->ensureSize();
   if (required_cmp.requiredsSave(vertex, this))
-    required_iter_->enqueueAdjacentVertices(vertex);
+    required_iter_->enqueueFanin(vertex);
 }
 
 void
@@ -3347,7 +3363,7 @@ Search::seedRequiredEnqueueFanin(Vertex *vertex)
   visit_path_ends_->visitPathEnds(vertex, &seeder);
   // Enqueue fanin vertices for back-propagating required times.
   required_cmp.requiredsSave(vertex, this);
-  required_iter_->enqueueAdjacentVertices(vertex);
+  required_iter_->enqueueFanin(vertex);
 }
 
 ////////////////////////////////////////////////////////////////
@@ -3455,7 +3471,7 @@ RequiredVisitor::visit(Vertex *vertex)
   search_->tnsInvalid(vertex);
 
   if (changed)
-    search_->requiredIterator()->enqueueAdjacentVertices(vertex);
+    search_->requiredIterator()->enqueueFanin(vertex);
 }
 
 bool
@@ -3538,17 +3554,27 @@ void
 Search::ensureDownstreamClkPins()
 {
   if (!found_downstream_clk_pins_) {
-    // Use backward BFS from register clk pins to mark upsteam pins
-    // as having downstream clk pins.
+    // Use backward DFS from register clk pins to mark upstream pins
+    // as having downstream clk pins. hasDownstreamClkPin doubles as the
+    // visited flag since its meaning is exactly "reached here".
     ClkTreeSearchPred pred(this);
-    BfsBkwdIterator iter(BfsIndex::other, &pred, this);
-    for (Vertex *vertex : graph_->regClkVertices())
-      iter.enqueue(vertex);
-
-    while (iter.hasNext()) {
-      Vertex *vertex = iter.next();
-      vertex->setHasDownstreamClkPin(true);
-      iter.enqueueAdjacentVertices(vertex);
+    std::vector<Vertex*> stack;
+    for (Vertex *vertex : graph_->regClkVertices()) {
+      if (!vertex->hasDownstreamClkPin()) {
+        vertex->setHasDownstreamClkPin(true);
+        stack.push_back(vertex);
+      }
+    }
+    while (!stack.empty()) {
+      Vertex *vertex = stack.back();
+      stack.pop_back();
+      graph_->visitFanins(vertex, &pred,
+                          [&stack] (Vertex *fanin) {
+                            if (!fanin->hasDownstreamClkPin()) {
+                              fanin->setHasDownstreamClkPin(true);
+                              stack.push_back(fanin);
+                            }
+                          });
     }
   }
   found_downstream_clk_pins_ = true;
diff --git a/search/Sta.cc b/search/Sta.cc
index 9eaa669e..a31721a8 100644
--- a/search/Sta.cc
+++ b/search/Sta.cc
@@ -4518,6 +4518,10 @@ Sta::makeInstanceAfter(const Instance *inst)
         if (pin) {
           Vertex *vertex, *bidir_drvr_vertex;
           graph_->makePinVertices(pin, vertex, bidir_drvr_vertex);
+          if (vertex)
+            search_->endpointInvalid(vertex);
+          if (bidir_drvr_vertex)
+            search_->endpointInvalid(bidir_drvr_vertex);
         }
       }
       graph_->makeInstanceEdges(inst);
@@ -4553,16 +4557,14 @@ Sta::replaceEquivCellBefore(const Instance *inst,
           VertexOutEdgeIterator edge_iter(vertex, graph_);
           while (edge_iter.hasNext()) {
             Edge *edge = edge_iter.next();
-            Vertex *to_vertex = edge->to(graph_);
-            if (network_->instance(to_vertex->pin()) == inst) {
+            if (!edge->isWire()) {
               TimingArcSet *from_set = edge->timingArcSet();
               // Find corresponding timing arc set.
               TimingArcSet *to_set = to_cell->findTimingArcSet(from_set);
               if (to_set)
                 edge->setTimingArcSet(to_set);
               else
-                report_->critical(
-                    1556, "corresponding timing arc set not found in equiv cells");
+                report_->critical(1563, "corresponding timing arc set not found in equiv cells");
             }
           }
         }
@@ -4658,8 +4660,7 @@ Sta::replaceCellBefore(const Instance *inst,
         VertexOutEdgeIterator edge_iter(vertex, graph_);
         while (edge_iter.hasNext()) {
           Edge *edge = edge_iter.next();
-          Vertex *to_vertex = edge->to(graph_);
-          if (network_->instance(to_vertex->pin()) == inst)
+          if (!edge->isWire())
             deleteEdge(edge);
         }
       }
diff --git a/search/test/search_network_sta_deep.ok b/search/test/search_network_sta_deep.ok
index 935f2435..9ce8d353 100644
--- a/search/test/search_network_sta_deep.ok
+++ b/search/test/search_network_sta_deep.ok
@@ -258,15 +258,15 @@ paths: 60
 --- report_tag_arrivals ---
 Vertex out1
 Group 2
- ^ min 0.100 / -2.000 16 default clk ^ clk_src clk crpr_pin null
- v min 0.099 / -2.000 17 default clk ^ clk_src clk crpr_pin null
- ^ max 0.100 / 8.000 18 default clk ^ clk_src clk crpr_pin null
- v max 0.099 / 8.000 19 default clk ^ clk_src clk crpr_pin null
+ ^ min 0.100 / -2.000 16 default clk ^ clk_src clk crpr_pin null prev buf2/Z ^ default/min 16 buf2/Z ^ -> out1 ^
+ v min 0.099 / -2.000 17 default clk ^ clk_src clk crpr_pin null prev buf2/Z v default/min 17 buf2/Z v -> out1 v
+ ^ max 0.100 / 8.000 18 default clk ^ clk_src clk crpr_pin null prev buf2/Z ^ default/max 18 buf2/Z ^ -> out1 ^
+ v max 0.099 / 8.000 19 default clk ^ clk_src clk crpr_pin null prev buf2/Z v default/max 19 buf2/Z v -> out1 v
 Vertex out1
- ^ min 0.100 / -2.000 default clk ^ clk_src clk crpr_pin null
- v min 0.099 / -2.000 default clk ^ clk_src clk crpr_pin null
- ^ max 0.100 / 8.000 default clk ^ clk_src clk crpr_pin null
- v max 0.099 / 8.000 default clk ^ clk_src clk crpr_pin null
+ ^ min 0.100 / -2.000 default clk ^ clk_src clk crpr_pin null prev buf2/Z ^ default/min 16 buf2/Z ^ -> out1 ^
+ v min 0.099 / -2.000 default clk ^ clk_src clk crpr_pin null prev buf2/Z v default/min 17 buf2/Z v -> out1 v
+ ^ max 0.100 / 8.000 default clk ^ clk_src clk crpr_pin null prev buf2/Z ^ default/max 18 buf2/Z ^ -> out1 ^
+ v max 0.099 / 8.000 default clk ^ clk_src clk crpr_pin null prev buf2/Z v default/max 19 buf2/Z v -> out1 v
 --- report_arrival_entries ---
 --- report_required_entries ---
 Level 40
diff --git a/search/test/search_search_arrival_required.ok b/search/test/search_search_arrival_required.ok
index 7fb42743..0ac18b74 100644
--- a/search/test/search_search_arrival_required.ok
+++ b/search/test/search_search_arrival_required.ok
@@ -68,15 +68,15 @@ worst_slack_path pin: out1
 worst_slack_path slack: 7.899713772019368e-9
 Vertex out1
 Group 2
- ^ min 0.100 / -2.000 16 default clk ^ clk_src clk crpr_pin null
- v min 0.099 / -2.000 17 default clk ^ clk_src clk crpr_pin null
- ^ max 0.100 / 8.000 18 default clk ^ clk_src clk crpr_pin null
- v max 0.099 / 8.000 19 default clk ^ clk_src clk crpr_pin null
+ ^ min 0.100 / -2.000 16 default clk ^ clk_src clk crpr_pin null prev buf2/Z ^ default/min 16 buf2/Z ^ -> out1 ^
+ v min 0.099 / -2.000 17 default clk ^ clk_src clk crpr_pin null prev buf2/Z v default/min 17 buf2/Z v -> out1 v
+ ^ max 0.100 / 8.000 18 default clk ^ clk_src clk crpr_pin null prev buf2/Z ^ default/max 18 buf2/Z ^ -> out1 ^
+ v max 0.099 / 8.000 19 default clk ^ clk_src clk crpr_pin null prev buf2/Z v default/max 19 buf2/Z v -> out1 v
 Vertex out1
- ^ min 0.100 / -2.000 default clk ^ clk_src clk crpr_pin null
- v min 0.099 / -2.000 default clk ^ clk_src clk crpr_pin null
- ^ max 0.100 / 8.000 default clk ^ clk_src clk crpr_pin null
- v max 0.099 / 8.000 default clk ^ clk_src clk crpr_pin null
+ ^ min 0.100 / -2.000 default clk ^ clk_src clk crpr_pin null prev buf2/Z ^ default/min 16 buf2/Z ^ -> out1 ^
+ v min 0.099 / -2.000 default clk ^ clk_src clk crpr_pin null prev buf2/Z v default/min 17 buf2/Z v -> out1 v
+ ^ max 0.100 / 8.000 default clk ^ clk_src clk crpr_pin null prev buf2/Z ^ default/max 18 buf2/Z ^ -> out1 ^
+ v max 0.099 / 8.000 default clk ^ clk_src clk crpr_pin null prev buf2/Z v default/max 19 buf2/Z v -> out1 v
 --- worst_slack_vertex min ---
 worst_slack_vertex min pin: reg1/D
 worst_arrival_path min pin: reg1/D
diff --git a/tcl/Property.tcl b/tcl/Property.tcl
index 3f70adc6..4df5b196 100644
--- a/tcl/Property.tcl
+++ b/tcl/Property.tcl
@@ -120,5 +120,33 @@ proc get_property_object_type { object_type object_name quiet } {
   return [lindex $object 0]
 }
 
+define_cmd_args "define_property" \
+  {-object_type scene|mode -type bool|float|string property}
+
+proc define_property { args } {
+  parse_key_args "define_property" args keys {-object_type -type} flags {}
+  check_argc_eq1 "define_property" $args
+  if { ![info exists keys(-object_type)] } {
+    sta_error 2207 "define_property -object_type must be specified."
+  }
+  if { ![info exists keys(-type)] } {
+    sta_error 2208 "define_property -type must be specified."
+  }
+  define_property_cmd $keys(-object_type) [lindex $args 0] $keys(-type)
+}
+
+define_cmd_args "set_property" {object property value}
+
+proc set_property { args } {
+  check_argc_eq3 "set_property" $args
+  set object [lindex $args 0]
+  set prop [lindex $args 1]
+  set value [lindex $args 2]
+  if { ![is_object $object] } {
+    sta_error 2213 "set_property $object is not an object."
+  }
+  set_property_cmd $object [object_type $object] $prop $value
+}
+
 # sta namespace end.
 }
diff --git a/tcl/Sta.tcl b/tcl/Sta.tcl
index 0ec12a27..cffd6673 100644
--- a/tcl/Sta.tcl
+++ b/tcl/Sta.tcl
@@ -112,10 +112,10 @@ proc set_scene { args } {
 
 ################################################################
 
-define_cmd_args "get_scenes" {[-modes mode_names] scene_names}
+define_cmd_args "get_scenes" {[-modes mode_names] [-filter expr] scene_names}
 
 proc get_scenes { args } {
-  parse_key_args "get_scenes" args keys {-modes} flags {}
+  parse_key_args "get_scenes" args keys {-modes -filter} flags {}
   check_argc_eq0or1 "get_scenes" $args
 
   if { [llength $args] == 0 } {
@@ -132,18 +132,34 @@ proc get_scenes { args } {
       }
       lappend modes $mode
     }
-    return [find_mode_scenes_matching $scene_name $modes]
+    set scenes [find_mode_scenes_matching $scene_name $modes]
   } else {
-    return [find_scenes_matching $scene_name]
+    set scenes [find_scenes_matching $scene_name]
   }
+  if { [info exists keys(-filter)] } {
+    set scenes [filter_scenes $keys(-filter) $scenes]
+  }
+  return $scenes
 }
 
 ################################################################
 
-define_cmd_args "get_modes" {mode_name}
+define_cmd_args "get_modes" {[-filter expr] [mode_name]}
 
 proc get_modes { args } {
-  return [find_modes [lindex $args 0]]
+  parse_key_args "get_modes" args keys {-filter} flags {}
+  check_argc_eq0or1 "get_modes" $args
+
+  if { [llength $args] == 0 } {
+    set mode_name "*"
+  } else {
+    set mode_name [lindex $args 0]
+  }
+  set modes [find_modes $mode_name]
+  if { [info exists keys(-filter)] } {
+    set modes [filter_modes $keys(-filter) $modes]
+  }
+  return $modes
 }
 
 ################################################################
diff --git a/tcl/StaTclTypes.i b/tcl/StaTclTypes.i
index c8c62584..a89054fa 100644
--- a/tcl/StaTclTypes.i
+++ b/tcl/StaTclTypes.i
@@ -1218,6 +1218,10 @@ using namespace sta;
   $1 = tclListSeq<Mode*>($input, SWIGTYPE_p_Mode, interp);
 }
 
+%typemap(in) ModeSeq* {
+  $1 = tclListSeqPtr<Mode*>($input, SWIGTYPE_p_Mode, interp);
+}
+
 %typemap(out) ModeSeq {
   seqTclList<ModeSeq, Mode>($1, SWIGTYPE_p_Mode, interp);
 }
@@ -1251,6 +1255,10 @@ using namespace sta;
   $1 = tclListSeq<Scene*>($input, SWIGTYPE_p_Scene, interp);
 }
 
+%typemap(in) SceneSeq* {
+  $1 = tclListSeqPtr<Scene*>($input, SWIGTYPE_p_Scene, interp);
+}
+
 %typemap(out) SceneSeq {
   seqTclList<SceneSeq, Scene>($1, SWIGTYPE_p_Scene, interp);
 }
diff --git a/test/asap7_small.lib.gz b/test/asap7_small.lib.gz
index f0381ded..47c561fb 100644
Binary files a/test/asap7_small.lib.gz and b/test/asap7_small.lib.gz differ
diff --git a/test/get_scenes.ok b/test/get_scenes.ok
index ab504b68..94478689 100644
--- a/test/get_scenes.ok
+++ b/test/get_scenes.ok
@@ -4,3 +4,30 @@ scene2
 [get_modes *]
 mode1
 mode2
+[get_scenes -filter {name == scene1}]
+scene1
+[get_scenes -filter {name =~ scene*}]
+scene1
+scene2
+[get_scenes -filter {name != scene1}]
+scene2
+[get_modes -filter {name == mode2}]
+mode2
+[get_modes -filter {name =~ mode*}]
+mode1
+mode2
+[get_property scene1 active]
+1
+[get_property scene2 active] (unset)
+<>
+[get_scenes -filter {active == true}]
+scene1
+[get_scenes -filter {active == false}] (scene2 unset)
+[get_scenes -filter {active}]
+scene1
+[get_scenes -filter {!active}]
+scene2
+[get_property scene2 active] (set false)
+0
+[get_scenes -filter {active == false}] (scene2 set false)
+scene2
diff --git a/test/get_scenes.tcl b/test/get_scenes.tcl
index 396c32ce..0ccb98a4 100644
--- a/test/get_scenes.tcl
+++ b/test/get_scenes.tcl
@@ -18,3 +18,47 @@ report_object_names [get_scenes *]
 
 puts {[get_modes *]}
 report_object_names [get_modes *]
+
+puts {[get_scenes -filter {name == scene1}]}
+report_object_names [get_scenes -filter {name == scene1}]
+
+puts {[get_scenes -filter {name =~ scene*}]}
+report_object_names [get_scenes -filter {name =~ scene*}]
+
+puts {[get_scenes -filter {name != scene1}]}
+report_object_names [get_scenes -filter {name != scene1}]
+
+puts {[get_modes -filter {name == mode2}]}
+report_object_names [get_modes -filter {name == mode2}]
+
+puts {[get_modes -filter {name =~ mode*}]}
+report_object_names [get_modes -filter {name =~ mode*}]
+
+# User-defined bool property. scene1 set active, scene2 left unset.
+define_property -object_type scene -type bool active
+set_property [get_scenes scene1] active true
+
+puts {[get_property scene1 active]}
+puts [get_property [get_scenes scene1] active]
+puts {[get_property scene2 active] (unset)}
+puts "<[get_property [get_scenes scene2] active]>"
+
+puts {[get_scenes -filter {active == true}]}
+report_object_names [get_scenes -filter {active == true}]
+
+# Unset does not match false; only an explicitly set value does.
+puts {[get_scenes -filter {active == false}] (scene2 unset)}
+report_object_names [get_scenes -filter {active == false}]
+
+puts {[get_scenes -filter {active}]}
+report_object_names [get_scenes -filter {active}]
+
+puts {[get_scenes -filter {!active}]}
+report_object_names [get_scenes -filter {!active}]
+
+set_property [get_scenes scene2] active false
+puts {[get_property scene2 active] (set false)}
+puts [get_property [get_scenes scene2] active]
+
+puts {[get_scenes -filter {active == false}] (scene2 set false)}
+report_object_names [get_scenes -filter {active == false}]