diff --git a/include/sta/Sdc.hh b/include/sta/Sdc.hh
index 2c730191..ba5fc14e 100644
--- a/include/sta/Sdc.hh
+++ b/include/sta/Sdc.hh
@@ -239,8 +239,8 @@ public:
 			const RiseFall *rf,
 			const EarlyLate *early_late) const;
   void unsetTimingDerate();
-  static void moveDeratingFactors(Sdc *from,
-                                  Sdc *to);
+  static void swapDeratingFactors(Sdc *sdc1,
+                                  Sdc *sdc2);
 
   void setInputSlew(const Port *port,
                     const RiseFallBoth *rf,
@@ -445,8 +445,8 @@ public:
 			 float delay);
   void removeClockInsertion(const Clock *clk,
 			    const Pin *pin);
-  static void moveClockInsertions(Sdc *from,
-                                  Sdc *to);
+  static void swapClockInsertions(Sdc *sdc1,
+                                  Sdc *sdc2);
   bool hasClockInsertion(const Pin *pin) const;
   float clockInsertion(const Clock *clk,
 		       const RiseFall *rf,
@@ -569,8 +569,8 @@ public:
 			 const Clock *clk,
 			 const RiseFall *clk_rf,
 			 const MinMaxAll *min_max);
-  static void movePortDelays(Sdc *from,
-                             Sdc *to);
+  static void swapPortDelays(Sdc *sdc1,
+                             Sdc *sdc2);
 
   // Set port external pin load (set_load -pin_load port).
   void setPortExtPinCap(const Port *port,
@@ -585,8 +585,8 @@ public:
 			 const Corner *corner,
 			 const MinMax *min_max,
 			 float cap);
-  static void movePortExtCaps(Sdc *from,
-                              Sdc *to);
+  static void swapPortExtCaps(Sdc *sdc1,
+                              Sdc *sdc2);
   // Remove all "set_load net" annotations.
   void removeNetLoadCaps();
   void setNetWireCap(const Net *net,
diff --git a/sdc/Sdc.cc b/sdc/Sdc.cc
index c78edd4d..bbf0106e 100644
--- a/sdc/Sdc.cc
+++ b/sdc/Sdc.cc
@@ -51,6 +51,8 @@
 
 namespace sta {
 
+using std::swap;
+
 bool
 ClockPairLess::operator()(const ClockPair &pair1,
 			  const ClockPair &pair2) const
@@ -660,17 +662,13 @@ Sdc::unsetTimingDerate()
 }
 
 void
-Sdc::moveDeratingFactors(Sdc *from,
-                         Sdc *to)
+Sdc::swapDeratingFactors(Sdc *sdc1,
+                         Sdc *sdc2)
 {
-  if (from->derating_factors_) {
-    to->derating_factors_ = from->derating_factors_;
-    from->derating_factors_ = nullptr;
-  }
-
-  to->net_derating_factors_ = std::move(from->net_derating_factors_);
-  to->inst_derating_factors_ = std::move(from->inst_derating_factors_);
-  to->cell_derating_factors_ = std::move(from->cell_derating_factors_);
+  swap(sdc1->derating_factors_, sdc2->derating_factors_);
+  swap(sdc1->net_derating_factors_, sdc2->net_derating_factors_);
+  swap(sdc1->inst_derating_factors_, sdc2->inst_derating_factors_);
+  swap(sdc1->cell_derating_factors_, sdc2->cell_derating_factors_);
 }
 
 void
@@ -1733,10 +1731,10 @@ Sdc::removeClockInsertion(const Clock *clk,
 }
 
 void
-Sdc::moveClockInsertions(Sdc *from,
-                         Sdc *to)
+Sdc::swapClockInsertions(Sdc *sdc1,
+                         Sdc *sdc2)
 {
-  to->clk_insertions_ = std::move(from->clk_insertions_);
+  swap(sdc1->clk_insertions_, sdc2->clk_insertions_);
 }
 
 void
@@ -2742,21 +2740,20 @@ Sdc::deleteInputDelay(InputDelay *input_delay)
 }
 
 void
-Sdc::movePortDelays(Sdc *from,
-                    Sdc *to)
+Sdc::swapPortDelays(Sdc *sdc1,
+                    Sdc *sdc2)
 {
-  to->input_delays_ = std::move(from->input_delays_);
-  to->input_delay_pin_map_ = std::move(from->input_delay_pin_map_);
-  to->input_delay_ref_pin_map_ = std::move(from->input_delay_ref_pin_map_);
-  to->input_delay_leaf_pin_map_ = std::move(from->input_delay_leaf_pin_map_);
-  to->input_delay_internal_pin_map_ = std::move(from->input_delay_internal_pin_map_);
-  to->input_delay_index_ = from->input_delay_index_;
-  from->input_delay_index_ = 0;
+  swap(sdc1->input_delays_, sdc2->input_delays_);
+  swap(sdc1->input_delay_pin_map_, sdc2->input_delay_pin_map_);
+  swap(sdc1->input_delay_ref_pin_map_, sdc2->input_delay_ref_pin_map_);
+  swap(sdc1->input_delay_leaf_pin_map_, sdc2->input_delay_leaf_pin_map_);
+  swap(sdc1->input_delay_internal_pin_map_, sdc2->input_delay_internal_pin_map_);
+  swap(sdc1->input_delay_index_, sdc2->input_delay_index_);
 
-  to->output_delays_ = std::move(from->output_delays_);
-  to->output_delay_pin_map_ = std::move(from->output_delay_pin_map_);
-  to->output_delay_ref_pin_map_ = std::move(from->output_delay_ref_pin_map_);
-  to->output_delay_leaf_pin_map_ = std::move(from->output_delay_leaf_pin_map_);
+  swap(sdc1->output_delays_, sdc2->output_delays_);
+  swap(sdc1->output_delay_pin_map_, sdc2->output_delay_pin_map_);
+  swap(sdc1->output_delay_ref_pin_map_, sdc2->output_delay_ref_pin_map_);
+  swap(sdc1->output_delay_leaf_pin_map_, sdc2->output_delay_leaf_pin_map_);
 }
 
 ////////////////////////////////////////////////////////////////
@@ -3322,15 +3319,12 @@ Sdc::ensurePortExtPinCap(const Port *port,
 }
 
 void
-Sdc::movePortExtCaps(Sdc *from,
-                     Sdc *to)
+Sdc::swapPortExtCaps(Sdc *sdc1,
+                     Sdc *sdc2)
 {
-  for (int corner_index = 0; corner_index < from->corners()->count(); corner_index++) {
-    to->port_ext_cap_maps_[corner_index] =
-      std::move(from->port_ext_cap_maps_[corner_index]);
-
-    to->net_wire_cap_maps_[corner_index] =
-      std::move(from->net_wire_cap_maps_[corner_index]);
+  for (int corner_index = 0; corner_index < sdc1->corners()->count(); corner_index++) {
+    swap(sdc1->port_ext_cap_maps_[corner_index], sdc2->port_ext_cap_maps_[corner_index]);
+    swap(sdc1->net_wire_cap_maps_[corner_index], sdc2->net_wire_cap_maps_[corner_index]);
   }
 }
 
diff --git a/search/MakeTimingModel.cc b/search/MakeTimingModel.cc
index 10867949..eb6941b5 100644
--- a/search/MakeTimingModel.cc
+++ b/search/MakeTimingModel.cc
@@ -111,24 +111,27 @@ void
 MakeTimingModel::saveSdc()
 {
   sdc_backup_ = new Sdc(this);
-  Sdc::movePortDelays(sdc_, sdc_backup_);
-  Sdc::movePortExtCaps(sdc_, sdc_backup_);
-  Sdc::moveDeratingFactors(sdc_, sdc_backup_);
-  Sdc::moveClockInsertions(sdc_, sdc_backup_);
+  swapSdcWithBackup();
   sta_->delaysInvalid();
 }
 
 void
 MakeTimingModel::restoreSdc()
 {
-  Sdc::movePortDelays(sdc_backup_, sdc_);
-  Sdc::movePortExtCaps(sdc_backup_, sdc_);
-  Sdc::moveDeratingFactors(sdc_backup_, sdc_);
-  Sdc::moveClockInsertions(sdc_backup_, sdc_);
+  swapSdcWithBackup();
   delete sdc_backup_;
   sta_->delaysInvalid();
 }
 
+void
+MakeTimingModel::swapSdcWithBackup()
+{
+  Sdc::swapPortDelays(sdc_, sdc_backup_);
+  Sdc::swapPortExtCaps(sdc_, sdc_backup_);
+  Sdc::swapDeratingFactors(sdc_, sdc_backup_);
+  Sdc::swapClockInsertions(sdc_, sdc_backup_);
+}
+
 void
 MakeTimingModel::makeLibrary()
 {
diff --git a/search/MakeTimingModelPvt.hh b/search/MakeTimingModelPvt.hh
index e7587f6f..7e3b83e4 100644
--- a/search/MakeTimingModelPvt.hh
+++ b/search/MakeTimingModelPvt.hh
@@ -92,6 +92,7 @@ private:
 
   void saveSdc();
   void restoreSdc();
+  void swapSdcWithBackup();
 
   const char *lib_name_;
   const char *cell_name_;
diff --git a/search/Sta.cc b/search/Sta.cc
index 01a6766d..fd001418 100644
--- a/search/Sta.cc
+++ b/search/Sta.cc
@@ -2968,7 +2968,7 @@ Sta::netSlack(const Net *net,
 {
   ensureGraph();
   Slack slack = MinMax::min()->initValue();
-  NetPinIterator *pin_iter = network_->pinIterator(net);
+  NetConnectedPinIterator *pin_iter = network_->connectedPinIterator(net);
   while (pin_iter->hasNext()) {
     const Pin *pin = pin_iter->next();
     if (network_->isLoad(pin)) {
diff --git a/verilog/VerilogParse.yy b/verilog/VerilogParse.yy
index a7752bd6..17588bc3 100644
--- a/verilog/VerilogParse.yy
+++ b/verilog/VerilogParse.yy
@@ -505,9 +505,14 @@ attr_specs:
 
 attr_spec:
 	ID
-	{ $$ = new sta::VerilogAttributeEntry($1, "1"); }
+	{ $$ = new sta::VerilogAttributeEntry($1, "1");
+	  delete[] $1;
+	}
 | 	ID '=' attr_spec_value
-	{ $$ = new sta::VerilogAttributeEntry($1, $3); }
+	{ $$ = new sta::VerilogAttributeEntry($1, $3); 
+	  delete[] $1;
+	  delete[] $3;
+	}
 	;
 
 attr_spec_value:
diff --git a/verilog/VerilogReader.cc b/verilog/VerilogReader.cc
index c3649785..8980c7a0 100644
--- a/verilog/VerilogReader.cc
+++ b/verilog/VerilogReader.cc
@@ -424,8 +424,11 @@ VerilogReader::makeDcl(PortDirection *dir,
       dcl_count_++;
       return new VerilogDcl(dir, assign_args, attribute_stmts, line);
     }
-    else
+    else {
+      attribute_stmts->deleteContents();
+      delete attribute_stmts;
       return nullptr;
+    }
   }
   else {
     dcl_count_++;
diff --git a/verilog/VerilogWriter.cc b/verilog/VerilogWriter.cc
index e3362da3..799495e5 100644
--- a/verilog/VerilogWriter.cc
+++ b/verilog/VerilogWriter.cc
@@ -214,9 +214,9 @@ VerilogWriter::verilogPortDir(PortDirection *dir)
   else if (dir == PortDirection::bidirect())
     return "inout";
   else if (dir == PortDirection::power())
-    return "input";
+    return "inout";
   else if (dir == PortDirection::ground())
-    return "input";
+    return "inout";
   else if (dir == PortDirection::internal())
     return nullptr;
   else {
@@ -412,7 +412,8 @@ VerilogWriter::writeAssigns(Instance *inst)
     Net *net = network_->net(term);
     Port *port = network_->port(pin);
     if (port
-        && network_->direction(port)->isAnyOutput()
+        && (network_->direction(port)->isAnyOutput()
+            || network_->direction(port)->isPowerGround())
         && !stringEqual(network_->name(port), network_->name(net))) {
       // Port name is different from net name.
       string port_vname = netVerilogName(network_->name(port),