diff --git a/dcalc/GraphDelayCalc.cc b/dcalc/GraphDelayCalc.cc
index 741353bf..3bf51343 100644
--- a/dcalc/GraphDelayCalc.cc
+++ b/dcalc/GraphDelayCalc.cc
@@ -292,6 +292,7 @@ class FindVertexDelays : public VertexVisitor
 {
 public:
   FindVertexDelays(GraphDelayCalc *graph_delay_calc1);
+  FindVertexDelays(const FindVertexDelays &find_vertex_delays);
   ~FindVertexDelays() override;
   void visit(Vertex *vertex) override;
   VertexVisitor *copy() const override;
@@ -308,6 +309,11 @@ FindVertexDelays::FindVertexDelays(GraphDelayCalc *graph_delay_calc) :
 {
 }
 
+FindVertexDelays::FindVertexDelays(const FindVertexDelays &find_vertex_delays) :
+  FindVertexDelays(find_vertex_delays.graph_delay_calc_)
+{
+}
+
 FindVertexDelays::~FindVertexDelays()
 {
   delete arc_delay_calc_;
@@ -318,7 +324,7 @@ FindVertexDelays::copy() const
 {
   // Copy StaState::arc_delay_calc_ because it needs separate state
   // for each thread.
-  return new FindVertexDelays(graph_delay_calc_);
+  return new FindVertexDelays(*this);
 }
 
 void
diff --git a/include/sta/Search.hh b/include/sta/Search.hh
index 58506e1f..2db5b6d5 100644
--- a/include/sta/Search.hh
+++ b/include/sta/Search.hh
@@ -770,6 +770,7 @@ class ArrivalVisitor : public PathVisitor
 {
 public:
   ArrivalVisitor(const StaState *sta);
+  ArrivalVisitor(const ArrivalVisitor &arrival_visitor);
   ~ArrivalVisitor() override;
   // Initialize the visitor.
   void init(bool always_to_endpoints,
@@ -797,9 +798,6 @@ public:
   TagGroupBldr *tagBldr() const { return tag_bldr_; }
 
 protected:
-  ArrivalVisitor(bool always_to_endpoints,
-                 SearchPred *pred,
-                 const StaState *sta);
   void init0();
   void enqueueRefPinInputDelays(const Pin *ref_pin,
                                 const Sdc *sdc);
@@ -842,6 +840,7 @@ class RequiredVisitor : public PathVisitor
 {
 public:
   RequiredVisitor(const StaState *sta);
+  RequiredVisitor(const RequiredVisitor &required_visitor);
   ~RequiredVisitor() override;
   VertexVisitor *copy() const override;
   void visit(Vertex *vertex) override;
@@ -862,9 +861,6 @@ public:
                        const MinMax *min_max) override;
 
 protected:
-  RequiredVisitor(bool make_tag_cache,
-                  const StaState *sta);
-
   RequiredCmp *required_cmp_;
   VisitPathEnds *visit_path_ends_;
 };
diff --git a/power/Power.cc b/power/Power.cc
index f5333f62..c5075522 100644
--- a/power/Power.cc
+++ b/power/Power.cc
@@ -575,6 +575,7 @@ public:
   PropActivityVisitor(Power *power,
                       const Mode *mode,
                       BfsFwdIterator *bfs);
+  PropActivityVisitor(const PropActivityVisitor &visitor);
   VertexVisitor *copy() const override;
   void visit(Vertex *vertex) override;
   InstanceSet &visitedRegs() { return visited_regs_; }
@@ -606,10 +607,15 @@ PropActivityVisitor::PropActivityVisitor(Power *power,
 {
 }
 
+PropActivityVisitor::PropActivityVisitor(const PropActivityVisitor &visitor) :
+  PropActivityVisitor(visitor.power_, visitor.mode_, visitor.bfs_)
+{
+}
+
 VertexVisitor *
 PropActivityVisitor::copy() const
 {
-  return new PropActivityVisitor(power_, mode_, bfs_);
+  return new PropActivityVisitor(*this);
 }
 
 void
diff --git a/search/Genclks.cc b/search/Genclks.cc
index 2123ea1b..6e8a39b7 100644
--- a/search/Genclks.cc
+++ b/search/Genclks.cc
@@ -693,17 +693,11 @@ public:
                           BfsFwdIterator *insert_iter,
                           GenclkInfo *genclk_info,
                           const Mode *mode);
+  GenclkSrcArrivalVisitor(const GenclkSrcArrivalVisitor &visitor);
   VertexVisitor *copy() const override;
   void visit(Vertex *vertex) override;
 
 protected:
-  GenclkSrcArrivalVisitor(Clock *gclk,
-                          BfsFwdIterator *insert_iter,
-                          GenclkInfo *genclk_info,
-                          bool always_to_endpoints,
-                          SearchPred *pred,
-                          const Mode *mode);
-
   Clock *gclk_;
   BfsFwdIterator *insert_iter_;
   GenclkInfo *genclk_info_;
@@ -728,29 +722,22 @@ GenclkSrcArrivalVisitor::GenclkSrcArrivalVisitor(Clock *gclk,
 {
 }
 
-// Copy constructor.
-GenclkSrcArrivalVisitor::GenclkSrcArrivalVisitor(Clock *gclk,
-                                                 BfsFwdIterator *insert_iter,
-                                                 GenclkInfo *genclk_info,
-                                                 bool always_to_endpoints,
-                                                 SearchPred *pred,
-                                                 const Mode *mode) :
-  ArrivalVisitor(always_to_endpoints, pred, this),
-  gclk_(gclk),
-  insert_iter_(insert_iter),
-  genclk_info_(genclk_info),
-  srch_pred_(gclk, genclk_info, this),
-  mode_(mode),
-  sdc_(mode->sdc()),
-  genclks_(mode->genclks())
+GenclkSrcArrivalVisitor::GenclkSrcArrivalVisitor(const GenclkSrcArrivalVisitor &visitor) :
+  ArrivalVisitor(static_cast<const ArrivalVisitor &>(visitor)),
+  gclk_(visitor.gclk_),
+  insert_iter_(visitor.insert_iter_),
+  genclk_info_(visitor.genclk_info_),
+  srch_pred_(visitor.gclk_, visitor.genclk_info_, this),
+  mode_(visitor.mode_),
+  sdc_(visitor.sdc_),
+  genclks_(visitor.genclks_)
 {
 }
 
 VertexVisitor *
 GenclkSrcArrivalVisitor::copy() const
 {
-  return new GenclkSrcArrivalVisitor(gclk_, insert_iter_, genclk_info_,
-                                     always_to_endpoints_, pred_, mode_);
+  return new GenclkSrcArrivalVisitor(*this);
 }
 
 void
diff --git a/search/PathEnum.cc b/search/PathEnum.cc
index c285b8f9..7c65f26e 100644
--- a/search/PathEnum.cc
+++ b/search/PathEnum.cc
@@ -246,6 +246,7 @@ public:
                        bool unique_pins,
                        bool unique_edges,
                        PathEnum *path_enum);
+  PathEnumFaninVisitor(const PathEnumFaninVisitor &visitor);
   VertexVisitor *copy() const override;
   void visitFaninPathsThru(Path *before_div,
                            Vertex *prev_vertex,
@@ -327,11 +328,16 @@ PathEnumFaninVisitor::PathEnumFaninVisitor(PathEnd *path_end,
 {
 }
 
+PathEnumFaninVisitor::PathEnumFaninVisitor(const PathEnumFaninVisitor &visitor) :
+  PathEnumFaninVisitor(visitor.path_end_, visitor.before_div_, visitor.unique_pins_,
+                       visitor.unique_edges_, visitor.path_enum_)
+{
+}
+
 VertexVisitor *
 PathEnumFaninVisitor::copy() const
 {
-  return new PathEnumFaninVisitor(path_end_, before_div_, unique_pins_,
-                                  unique_edges_, path_enum_);
+  return new PathEnumFaninVisitor(*this);
 }
 
 void
diff --git a/search/PathGroup.cc b/search/PathGroup.cc
index 6750613c..725b52c7 100644
--- a/search/PathGroup.cc
+++ b/search/PathGroup.cc
@@ -995,7 +995,7 @@ MakeEndpointPathEnds::~MakeEndpointPathEnds()
 VertexVisitor *
 MakeEndpointPathEnds::copy() const
 {
-  return new MakeEndpointPathEnds(path_end_visitor_, scenes_, min_max_, sta_);
+  return new MakeEndpointPathEnds(*this);
 }
 
 void
diff --git a/search/Search.cc b/search/Search.cc
index 081daac8..0bc491f3 100644
--- a/search/Search.cc
+++ b/search/Search.cc
@@ -1090,14 +1090,11 @@ ArrivalVisitor::ArrivalVisitor(const StaState *sta) :
   init(true, false, nullptr);
 }
 
-// Copy constructor.
-ArrivalVisitor::ArrivalVisitor(bool always_to_endpoints,
-                               SearchPred *pred,
-                               const StaState *sta) :
-  PathVisitor(pred, true, sta)
+ArrivalVisitor::ArrivalVisitor(const ArrivalVisitor &arrival_visitor) :
+  PathVisitor(arrival_visitor.pred_, true, &arrival_visitor)
 {
   init0();
-  init(always_to_endpoints, false, pred);
+  init(arrival_visitor.always_to_endpoints_, false, arrival_visitor.pred_);
 }
 
 void
@@ -1122,7 +1119,7 @@ ArrivalVisitor::init(bool always_to_endpoints,
 VertexVisitor *
 ArrivalVisitor::copy() const
 {
-  return new ArrivalVisitor(always_to_endpoints_, pred_, this);
+  return new ArrivalVisitor(*this);
 }
 
 void
@@ -1966,7 +1963,10 @@ PathVisitor::PathVisitor(SearchPred *pred,
 {
 }
 
-PathVisitor::~PathVisitor() { delete tag_cache_; }
+PathVisitor::~PathVisitor()
+{
+  delete tag_cache_;
+}
 
 void
 PathVisitor::visitFaninPaths(Vertex *to_vertex)
@@ -3447,13 +3447,10 @@ RequiredVisitor::RequiredVisitor(const StaState *sta) :
 {
 }
 
-RequiredVisitor::RequiredVisitor(bool make_tag_cache,
-                                 const StaState *sta) :
-  PathVisitor(sta->search()->evalPred(),
-              make_tag_cache,
-              sta),
+RequiredVisitor::RequiredVisitor(const RequiredVisitor &required_visitor) :
+  PathVisitor(required_visitor.search()->evalPred(), true, &required_visitor),
   required_cmp_(new RequiredCmp),
-  visit_path_ends_(new VisitPathEnds(sta))
+  visit_path_ends_(new VisitPathEnds(&required_visitor))
 {
 }
 
@@ -3466,7 +3463,7 @@ RequiredVisitor::~RequiredVisitor()
 VertexVisitor *
 RequiredVisitor::copy() const
 {
-  return new RequiredVisitor(true, this);
+  return new RequiredVisitor(*this);
 }
 
 void