diff --git a/CMakeLists.txt b/CMakeLists.txt
index fa6dd609..67b8de44 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -24,7 +24,7 @@ if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.14)
 cmake_policy(SET CMP0086 NEW)
 endif()
 
-project(STA VERSION 2.1.0
+project(STA VERSION 2.2.0
   LANGUAGES CXX
 )
 
@@ -141,6 +141,7 @@ set(STA_SOURCE
   sdc/RiseFallMinMax.cc
   sdc/RiseFallValues.cc
   sdc/Sdc.cc
+  sdc/SdcGraph.cc
   sdc/SdcCmdComment.cc
   sdc/WriteSdc.cc
   
@@ -329,7 +330,7 @@ swig_add_library(sta_swig
   SOURCES ${STA_SWIG_FILE}
 )
 
-swig_link_libraries(sta_swig
+target_link_libraries(sta_swig
   PUBLIC
   OpenSTA
 )
@@ -477,8 +478,8 @@ target_compile_options(sta
   )
 
 target_link_libraries(sta
-  OpenSTA
   sta_swig
+  OpenSTA
   ${TCL_LIBRARY}
   )
 
diff --git a/app/StaMain.cc b/app/StaMain.cc
index 88d5821d..aaed624a 100644
--- a/app/StaMain.cc
+++ b/app/StaMain.cc
@@ -19,7 +19,6 @@
 #include <tcl.h>
 #include <stdlib.h>
 
-#include "util/Machine.hh"
 #include "StringUtil.hh"
 #include "Vector.hh"
 #include "Sta.hh"
diff --git a/dcalc/DmpDelayCalc.cc b/dcalc/DmpDelayCalc.cc
index 77ea8c11..44823aa7 100644
--- a/dcalc/DmpDelayCalc.cc
+++ b/dcalc/DmpDelayCalc.cc
@@ -347,7 +347,7 @@ DmpCeffTwoPoleDelayCalc::loadDelay(Parasitic *pole_residue,
 {
   ComplexFloat pole2, residue2;
   parasitics_->poleResidue(pole_residue, 1, pole2, residue2);
-  if (!fuzzyZero(drvr_slew_)
+  if (!delayZero(drvr_slew_)
       && pole2.imag() == 0.0
       && residue2.imag() == 0.0) {
     double p2 = pole2.real();
diff --git a/dcalc/GraphDelayCalc1.cc b/dcalc/GraphDelayCalc1.cc
index 33f4bdbd..99d97673 100644
--- a/dcalc/GraphDelayCalc1.cc
+++ b/dcalc/GraphDelayCalc1.cc
@@ -1246,7 +1246,7 @@ GraphDelayCalc1::findArcDelay(LibertyCell *drvr_cell,
     // Merge slews.
     const Slew &drvr_slew = graph_->slew(drvr_vertex, drvr_rf, ap_index);
     const MinMax *slew_min_max = dcalc_ap->slewMinMax();
-    if (fuzzyGreater(gate_slew, drvr_slew, dcalc_ap->slewMinMax())
+    if (delayGreater(gate_slew, drvr_slew, dcalc_ap->slewMinMax(), this)
 	&& !drvr_vertex->slewAnnotated(drvr_rf, slew_min_max))
       graph_->setSlew(drvr_vertex, drvr_rf, ap_index, gate_slew);
     if (!graph_->arcDelayAnnotated(edge, arc, ap_index)) {
@@ -1446,7 +1446,7 @@ GraphDelayCalc1::annotateLoadDelays(Vertex *drvr_vertex,
 	else {
 	  const Slew &slew = graph_->slew(load_vertex, drvr_rf, ap_index);
 	  if (!merge
-	      || fuzzyGreater(load_slew, slew, slew_min_max))
+	      || delayGreater(load_slew, slew, slew_min_max, this))
 	    graph_->setSlew(load_vertex, drvr_rf, ap_index, load_slew);
 	}
       }
@@ -1459,7 +1459,7 @@ GraphDelayCalc1::annotateLoadDelays(Vertex *drvr_vertex,
 	Delay wire_delay_extra = extra_delay + wire_delay;
 	const MinMax *delay_min_max = dcalc_ap->delayMinMax();
 	if (!merge
-	    || fuzzyGreater(wire_delay_extra, delay, delay_min_max)) {
+	    || delayGreater(wire_delay_extra, delay, delay_min_max, this)) {
 	  graph_->setWireArcDelay(wire_edge, drvr_rf, ap_index,
 				  wire_delay_extra);
 	  if (observer_)
diff --git a/doc/OpenSTA.odt b/doc/OpenSTA.odt
index 1eb3cf7b..6c52b060 100644
Binary files a/doc/OpenSTA.odt and b/doc/OpenSTA.odt differ
diff --git a/graph/DelayFloat.cc b/graph/DelayFloat.cc
index 2b06819a..9fda2611 100644
--- a/graph/DelayFloat.cc
+++ b/graph/DelayFloat.cc
@@ -35,19 +35,6 @@ initDelayConstants()
   delay_init_values[MinMax::maxIndex()] = MinMax::max()->initValue();
 }
 
-const Delay &
-delayInitValue(const MinMax *min_max)
-{
-  return delay_init_values[min_max->index()];
-}
-
-bool
-delayIsInitValue(const Delay &delay,
-		 const MinMax *min_max)
-{
-  return fuzzyEqual(delay, min_max->initValue());
-}
-
 const char *
 delayAsString(const Delay &delay,
 	      const StaState *sta)
@@ -73,25 +60,91 @@ delayAsString(const Delay &delay,
   return unit->asString(delay, digits);
 }
 
-float
-delayAsFloat(const Delay &delay,
-	     const EarlyLate *,
+const Delay &
+delayInitValue(const MinMax *min_max)
+{
+  return delay_init_values[min_max->index()];
+}
+
+bool
+delayIsInitValue(const Delay &delay,
+		 const MinMax *min_max)
+{
+  return fuzzyEqual(delay, min_max->initValue());
+}
+
+bool
+delayZero(const Delay &delay)
+{
+  return fuzzyZero(delay);
+}
+
+bool
+delayInf(const Delay &delay)
+{
+  return fuzzyInf(delay);
+}
+
+bool
+delayEqual(const Delay &delay1,
+	   const Delay &delay2)
+{
+  return fuzzyEqual(delay1, delay2);
+}
+
+bool
+delayLess(const Delay &delay1,
+	  const Delay &delay2,
+	  const StaState *)
+{
+  return fuzzyLess(delay1, delay2);
+}
+
+bool
+delayLess(const Delay &delay1,
+	  const Delay &delay2,
+	  const MinMax *min_max,
+	  const StaState *)
+{
+  if (min_max == MinMax::max())
+    return fuzzyLess(delay1, delay2);
+  else
+    return fuzzyGreater(delay1, delay2);
+}
+
+bool
+delayLessEqual(const Delay &delay1,
+	       const Delay &delay2,
+	       const StaState *)
+{
+  return fuzzyLessEqual(delay1, delay2);
+}
+
+bool
+delayLessEqual(const Delay &delay1,
+	       const Delay &delay2,
+	       const MinMax *min_max,
+	       const StaState *)
+{
+  if (min_max == MinMax::max())
+    return fuzzyLessEqual(delay1, delay2);
+  else
+    return fuzzyGreaterEqual(delay1, delay2);
+}
+
+bool
+delayGreater(const Delay &delay1,
+	     const Delay &delay2,
 	     const StaState *)
 {
-  return delay;
-}
-
-float
-delaySigma2(const Delay &,
-	   const EarlyLate *)
-{
-  return 0.0;
+  return fuzzyGreater(delay1, delay2);
 }
 
 bool
-fuzzyGreater(const Delay &delay1,
+delayGreater(const Delay &delay1,
 	     const Delay &delay2,
-	     const MinMax *min_max)
+	     const MinMax *min_max,
+	     const StaState *)
 {
   if (min_max == MinMax::max())
     return fuzzyGreater(delay1, delay2);
@@ -100,9 +153,18 @@ fuzzyGreater(const Delay &delay1,
 }
 
 bool
-fuzzyGreaterEqual(const Delay &delay1,
+delayGreaterEqual(const Delay &delay1,
 		  const Delay &delay2,
-		  const MinMax *min_max)
+		  const StaState *)
+{
+  return fuzzyGreaterEqual(delay1, delay2);
+}
+
+bool
+delayGreaterEqual(const Delay &delay1,
+		  const Delay &delay2,
+		  const MinMax *min_max,
+		  const StaState *)
 {
   if (min_max == MinMax::max())
     return fuzzyGreaterEqual(delay1, delay2);
@@ -110,28 +172,6 @@ fuzzyGreaterEqual(const Delay &delay1,
     return fuzzyLessEqual(delay1, delay2);
 }
 
-bool
-fuzzyLess(const Delay &delay1,
-	  const Delay &delay2,
-	  const MinMax *min_max)
-{
-  if (min_max == MinMax::max())
-    return fuzzyLess(delay1, delay2);
-  else
-    return fuzzyGreater(delay1, delay2);
-}
-
-bool
-fuzzyLessEqual(const Delay &delay1,
-	       const Delay &delay2,
-	       const MinMax *min_max)
-{
-  if (min_max == MinMax::max())
-    return fuzzyLessEqual(delay1, delay2);
-  else
-    return fuzzyGreaterEqual(delay1, delay2);
-}
-
 Delay
 delayRemove(const Delay &delay1,
 	    const Delay &delay2)
diff --git a/graph/DelayNormal1.cc b/graph/DelayNormal1.cc
index f0d58659..3b2f5edb 100644
--- a/graph/DelayNormal1.cc
+++ b/graph/DelayNormal1.cc
@@ -162,32 +162,7 @@ Delay::operator-=(const Delay &delay)
 bool
 Delay::operator==(const Delay &delay) const
 {
-  return mean_ == delay.mean_
-    && sigma2_ == delay.sigma2_;
-}
-
-bool
-Delay::operator>(const Delay &delay) const
-{
-  return mean_ > delay.mean_;
-}
-
-bool
-Delay::operator>=(const Delay &delay) const
-{
-  return mean_ >= delay.mean_;
-}
-
-bool
-Delay::operator<(const Delay &delay) const
-{
-  return mean_ < delay.mean_;
-}
-
-bool
-Delay::operator<=(const Delay &delay) const
-{
-  return mean_ <= delay.mean_;
+  return delayEqual(*this, delay);
 }
 
 ////////////////////////////////////////////////////////////////
@@ -208,135 +183,6 @@ makeDelay2(float delay,
   return Delay(delay, sigma2);
 }
 
-bool
-delayIsInitValue(const Delay &delay,
-		 const MinMax *min_max)
-{
-  return fuzzyEqual(delay.mean(), min_max->initValue())
-    && delay.sigma2() == 0.0;
-}
-
-bool
-fuzzyZero(const Delay &delay)
-{
-  return fuzzyZero(delay.mean())
-    && fuzzyZero(delay.sigma2());
-}
-
-bool
-fuzzyInf(const Delay &delay)
-{
-  return fuzzyInf(delay.mean());
-}
-
-bool
-fuzzyEqual(const Delay &delay1,
-	   const Delay &delay2)
-{
-  return fuzzyEqual(delay1.mean(), delay2.mean())
-    && fuzzyEqual(delay1.sigma2(), delay2.sigma2());
-}
-
-bool
-fuzzyLess(const Delay &delay1,
-	  const Delay &delay2)
-{
-  return fuzzyLess(delay1.mean(), delay2.mean());
-}
-
-bool
-fuzzyLess(const Delay &delay1,
-	  float delay2)
-{
-  return fuzzyLess(delay1.mean(), delay2);
-}
-
-bool
-fuzzyLessEqual(const Delay &delay1,
-	       const Delay &delay2)
-{
-  return fuzzyLessEqual(delay1.mean(), delay2.mean());
-}
-
-bool
-fuzzyLessEqual(const Delay &delay1,
-		    float delay2)
-{
-  return fuzzyLessEqual(delay1.mean(), delay2);
-}
-
-bool
-fuzzyLessEqual(const Delay &delay1,
-	       const Delay &delay2,
-	       const MinMax *min_max)
-{
-  if (min_max == MinMax::max())
-    return fuzzyLessEqual(delay1.mean(), delay2.mean());
-  else
-    return fuzzyGreaterEqual(delay1.mean(), delay2.mean());
-}
-
-bool
-fuzzyGreater(const Delay &delay1,
-	     const Delay &delay2)
-{
-  return fuzzyGreater(delay1.mean(), delay2.mean());
-}
-
-bool
-fuzzyGreater(const Delay &delay1,
-	     float delay2)
-{
-  return fuzzyGreater(delay1.mean(), delay2);
-}
-
-bool
-fuzzyGreaterEqual(const Delay &delay1,
-		  const Delay &delay2)
-{
-  return fuzzyGreaterEqual(delay1.mean(), delay2.mean());
-}
-
-bool
-fuzzyGreaterEqual(const Delay &delay1,
-		  float delay2)
-{
-  return fuzzyGreaterEqual(delay1.mean(), delay2);
-}
-
-bool
-fuzzyGreater(const Delay &delay1,
-	     const Delay &delay2,
-	     const MinMax *min_max)
-{
-  if (min_max == MinMax::max())
-    return fuzzyGreater(delay1.mean(), delay2.mean());
-  else
-    return fuzzyLess(delay1.mean(), delay2.mean());
-}
-
-bool
-fuzzyGreaterEqual(const Delay &delay1,
-		  const Delay &delay2,
-		  const MinMax *min_max)
-{
-  if (min_max == MinMax::max())
-    return fuzzyGreaterEqual(delay1.mean(), delay2.mean());
-  else
-    return fuzzyLessEqual(delay1.mean(), delay2.mean());
-}
-
-bool
-fuzzyLess(const Delay &delay1,
-	  const Delay &delay2,
-	  const MinMax *min_max)
-{
-  if (min_max == MinMax::max())
-    return fuzzyLess(delay1.mean(), delay2.mean());
-  else
-    return fuzzyGreater(delay1.mean(), delay2.mean());
-}
-
 float
 delayAsFloat(const Delay &delay,
 	     const EarlyLate *early_late,
@@ -394,6 +240,156 @@ delayAsString(const Delay &delay,
   return sta->units()->timeUnit()->asString(mean_sigma, digits);
 }
 
+bool
+delayIsInitValue(const Delay &delay,
+		 const MinMax *min_max)
+{
+  return fuzzyEqual(delay.mean(), min_max->initValue())
+    && delay.sigma2() == 0.0;
+}
+
+bool
+delayZero(const Delay &delay)
+{
+  return fuzzyZero(delay.mean())
+    && fuzzyZero(delay.sigma2());
+}
+
+bool
+delayInf(const Delay &delay)
+{
+  return fuzzyInf(delay.mean());
+}
+
+bool
+delayEqual(const Delay &delay1,
+	   const Delay &delay2)
+{
+  return fuzzyEqual(delay1.mean(), delay2.mean())
+    && fuzzyEqual(delay1.sigma2(), delay2.sigma2());
+}
+
+bool
+delayLess(const Delay &delay1,
+	  const Delay &delay2,
+	  const StaState *sta)
+{
+  return fuzzyLess(delayAsFloat(delay1, EarlyLate::early(), sta),
+		   delayAsFloat(delay2, EarlyLate::early(), sta));
+}
+
+bool
+delayLess(const Delay &delay1,
+	  float delay2,
+	  const StaState *sta)
+{
+  return fuzzyLess(delayAsFloat(delay1, EarlyLate::early(), sta),
+		   delay2);
+}
+
+bool
+delayLess(const Delay &delay1,
+	  const Delay &delay2,
+	  const MinMax *min_max,
+	  const StaState *sta)
+{
+  if (min_max == MinMax::max())
+    return delayLess(delay1, delay2, sta);
+  else
+    return delayGreater(delay1, delay2, sta);
+}
+
+bool
+delayLessEqual(const Delay &delay1,
+	       const Delay &delay2,
+	       const StaState *sta)
+{
+  return fuzzyLessEqual(delayAsFloat(delay1, EarlyLate::early(), sta),
+			delayAsFloat(delay2, EarlyLate::early(), sta));
+}
+
+bool
+delayLessEqual(const Delay &delay1,
+	       float delay2,
+	       const StaState *sta)
+{
+  return fuzzyLessEqual(delayAsFloat(delay1, EarlyLate::early(), sta),
+			delay2);
+}
+
+bool
+delayLessEqual(const Delay &delay1,
+	       const Delay &delay2,
+	       const MinMax *min_max,
+	       const StaState *sta)
+{
+  if (min_max == MinMax::max())
+    return delayLessEqual(delay1, delay2, sta);
+  else
+    return delayGreaterEqual(delay1, delay2, sta);
+}
+
+bool
+delayGreater(const Delay &delay1,
+	     const Delay &delay2,
+	     const StaState *sta)
+
+{
+  return fuzzyGreater(delayAsFloat(delay1, EarlyLate::late(), sta),
+		      delayAsFloat(delay2, EarlyLate::late(), sta));
+}
+
+bool
+delayGreater(const Delay &delay1,
+	     float delay2,
+	     const StaState *sta)
+{
+  return fuzzyGreater(delayAsFloat(delay1, EarlyLate::late(), sta),
+		      delay2);
+}
+
+bool
+delayGreaterEqual(const Delay &delay1,
+		  const Delay &delay2,
+		  const StaState *sta)
+{
+  return fuzzyGreaterEqual(delayAsFloat(delay1, EarlyLate::late(), sta),
+			   delayAsFloat(delay2, EarlyLate::late(), sta));
+}
+
+bool
+delayGreaterEqual(const Delay &delay1,
+		  float delay2,
+		  const StaState *sta)
+{
+  return fuzzyGreaterEqual(delayAsFloat(delay1, EarlyLate::late(), sta),
+			   delay2);
+}
+
+bool
+delayGreater(const Delay &delay1,
+	     const Delay &delay2,
+	     const MinMax *min_max,
+	     const StaState *sta)
+{
+  if (min_max == MinMax::max())
+    return delayGreater(delay1, delay2, sta);
+  else
+    return delayLess(delay1, delay2, sta);
+}
+
+bool
+delayGreaterEqual(const Delay &delay1,
+		  const Delay &delay2,
+		  const MinMax *min_max,
+		  const StaState *sta)
+{
+  if (min_max == MinMax::max())
+    return delayGreaterEqual(delay1, delay2, sta);
+  else
+    return delayLessEqual(delay1, delay2, sta);
+}
+
 Delay
 delayRemove(const Delay &delay1,
 	    const Delay &delay2)
diff --git a/graph/DelayNormal2.cc b/graph/DelayNormal2.cc
index db5a7eca..883aa306 100644
--- a/graph/DelayNormal2.cc
+++ b/graph/DelayNormal2.cc
@@ -187,30 +187,6 @@ Delay::operator==(const Delay &delay) const
     && sigma2_[late_index]  == delay.sigma2_[early_index];
 }
 
-bool
-Delay::operator>(const Delay &delay) const
-{
-  return mean_ > delay.mean_;
-}
-
-bool
-Delay::operator>=(const Delay &delay) const
-{
-  return mean_ >= delay.mean_;
-}
-
-bool
-Delay::operator<(const Delay &delay) const
-{
-  return mean_ < delay.mean_;
-}
-
-bool
-Delay::operator<=(const Delay &delay) const
-{
-  return mean_ <= delay.mean_;
-}
-
 ////////////////////////////////////////////////////////////////
 
 Delay
@@ -234,12 +210,12 @@ delayIsInitValue(const Delay &delay,
 		 const MinMax *min_max)
 {
   return fuzzyEqual(delay.mean(), min_max->initValue())
-    && delay.sigma2Early() == 0.0
-    && delay.sigma2Late()  == 0.0;
+    && fuzzyZero(delay.sigma2Early())
+    && fuzzyZero(delay.sigma2Late());
 }
 
 bool
-fuzzyZero(const Delay &delay)
+delayZero(const Delay &delay)
 {
   return fuzzyZero(delay.mean())
     && fuzzyZero(delay.sigma2Early())
@@ -247,13 +223,13 @@ fuzzyZero(const Delay &delay)
 }
 
 bool
-fuzzyInf(const Delay &delay)
+delayInf(const Delay &delay)
 {
   return fuzzyInf(delay.mean());
 }
 
 bool
-fuzzyEqual(const Delay &delay1,
+delayEqual(const Delay &delay1,
 	   const Delay &delay2)
 {
   return fuzzyEqual(delay1.mean(), delay2.mean())
@@ -262,146 +238,123 @@ fuzzyEqual(const Delay &delay1,
 }
 
 bool
-fuzzyLess(const Delay &delay1,
-	  const Delay &delay2)
-{
-  return fuzzyLess(delay1.mean(), delay2.mean());
-}
-
-bool
-fuzzyLess(const Delay &delay1,
-	  float delay2)
-{
-  return fuzzyLess(delay1.mean(), delay2);
-}
-
-bool
-fuzzyLessEqual(const Delay &delay1,
-	       const Delay &delay2)
-{
-  return fuzzyLessEqual(delay1.mean(), delay2.mean());
-}
-
-bool
-fuzzyLessEqual(const Delay &delay1,
-		    float delay2)
-{
-  return fuzzyLessEqual(delay1.mean(), delay2);
-}
-
-bool
-fuzzyLessEqual(const Delay &delay1,
-	       const Delay &delay2,
-	       const MinMax *min_max)
-{
-  if (min_max == MinMax::max())
-    return fuzzyLessEqual(delay1.mean(), delay2.mean());
-  else
-    return fuzzyGreaterEqual(delay1.mean(), delay2.mean());
-}
-
-bool
-fuzzyGreater(const Delay &delay1,
-	     const Delay &delay2)
-{
-  return fuzzyGreater(delay1.mean(), delay2.mean());
-}
-
-bool
-fuzzyGreater(const Delay &delay1,
-	     float delay2)
-{
-  return fuzzyGreater(delay1.mean(), delay2);
-}
-
-bool
-fuzzyGreaterEqual(const Delay &delay1,
-		  const Delay &delay2)
-{
-  return fuzzyGreaterEqual(delay1.mean(), delay2.mean());
-}
-
-bool
-fuzzyGreaterEqual(const Delay &delay1,
-		  float delay2)
-{
-  return fuzzyGreaterEqual(delay1.mean(), delay2);
-}
-
-bool
-fuzzyGreater(const Delay &delay1,
-	     const Delay &delay2,
-	     const MinMax *min_max)
-{
-  if (min_max == MinMax::max())
-    return fuzzyGreater(delay1.mean(), delay2.mean());
-  else
-    return fuzzyLess(delay1.mean(), delay2.mean());
-}
-
-bool
-fuzzyGreaterEqual(const Delay &delay1,
-		  const Delay &delay2,
-		  const MinMax *min_max)
-{
-  if (min_max == MinMax::max())
-    return fuzzyGreaterEqual(delay1.mean(), delay2.mean());
-  else
-    return fuzzyLessEqual(delay1.mean(), delay2.mean());
-}
-
-bool
-fuzzyLess(const Delay &delay1,
+delayLess(const Delay &delay1,
 	  const Delay &delay2,
-	  const MinMax *min_max)
+	  const StaState *sta)
+{
+  return fuzzyLess(delayAsFloat(delay1, EarlyLate::early(), sta),
+		   delayAsFloat(delay2, EarlyLate::early(), sta));
+}
+
+bool
+delayLess(const Delay &delay1,
+	  float delay2,
+	  const StaState *sta)
+{
+  return fuzzyLess(delayAsFloat(delay1, EarlyLate::early(), sta),
+		   delay2);
+}
+
+bool
+delayLess(const Delay &delay1,
+	  const Delay &delay2,
+	  const MinMax *min_max,
+	  const StaState *sta)
 {
   if (min_max == MinMax::max())
-    return fuzzyLess(delay1.mean(), delay2.mean());
+    return delayLess(delay1, delay2, sta);
   else
-    return fuzzyGreater(delay1.mean(), delay2.mean());
+    return delayGreater(delay1, delay2, sta);
 }
 
-Delay
-operator+(float delay1,
-	  const Delay &delay2)
+bool
+delayLessEqual(const Delay &delay1,
+	       const Delay &delay2,
+	       const StaState *sta)
 {
-  return Delay(delay1 + delay2.mean(),
-	       delay2.sigma2Early(),
-	       delay2.sigma2Late());
+  return fuzzyLessEqual(delayAsFloat(delay1, EarlyLate::early(), sta),
+			delayAsFloat(delay2, EarlyLate::early(), sta));
 }
 
-Delay
-operator/(float delay1,
-	  const Delay &delay2)
+bool
+delayLessEqual(const Delay &delay1,
+	       float delay2,
+	       const StaState *sta)
 {
-  return Delay(delay1 / delay2.mean(),
-	       delay2.sigma2Early(),
-	       delay2.sigma2Late());
+  return fuzzyLessEqual(delayAsFloat(delay1, EarlyLate::early(), sta),
+			delay2);
 }
 
-Delay
-operator*(const Delay &delay1,
-	  float delay2)
+bool
+delayLessEqual(const Delay &delay1,
+	       const Delay &delay2,
+	       const MinMax *min_max,
+	       const StaState *sta)
 {
-  return Delay(delay1.mean() * delay2,
-	       delay1.sigma2Early() * delay2 * delay2,
-	       delay1.sigma2Late() * delay2 * delay2);
+  if (min_max == MinMax::max())
+    return delayLessEqual(delay1, delay2, sta);
+  else
+    return delayGreaterEqual(delay1, delay2, sta);
 }
 
-Delay
-delayRemove(const Delay &delay1,
-	    const Delay &delay2)
+bool
+delayGreater(const Delay &delay1,
+	     const Delay &delay2,
+	     const StaState *sta)
 {
-  return Delay(delay1.mean() - delay2.mean(),
-	       delay1.sigma2Early() - delay2.sigma2Early(),
-	       delay1.sigma2Late() - delay2.sigma2Late());
+  return fuzzyGreater(delayAsFloat(delay1, EarlyLate::late(), sta),
+		      delayAsFloat(delay2, EarlyLate::late(), sta));
 }
 
-float
-delayRatio(const Delay &delay1,
-	   const Delay &delay2)
+bool
+delayGreater(const Delay &delay1,
+	     float delay2,
+	     const StaState *sta)
 {
-  return delay1.mean() / delay2.mean();
+  return fuzzyGreaterEqual(delayAsFloat(delay1, EarlyLate::late(), sta),
+			   delayAsFloat(delay2, EarlyLate::late(), sta));
+}
+
+bool
+delayGreaterEqual(const Delay &delay1,
+		  const Delay &delay2,
+		  const StaState *sta)
+{
+  return fuzzyGreaterEqual(delayAsFloat(delay1, EarlyLate::late(), sta),
+			   delayAsFloat(delay2, EarlyLate::late(), sta));
+}
+
+bool
+delayGreaterEqual(const Delay &delay1,
+		  float delay2,
+		  const StaState *sta)
+{
+  return fuzzyGreaterEqual(delayAsFloat(delay1, EarlyLate::late(), sta),
+			   delay2);
+}
+
+bool
+delayGreater(const Delay &delay1,
+	     const Delay &delay2,
+	     const MinMax *min_max,
+	     const StaState *sta)
+{
+  if (min_max == MinMax::max())
+    return delayGreater(delay1, delay2, sta);
+  else
+    return delayLess(delay1, delay2, sta);
+}
+
+bool
+delayGreaterEqual(const Delay &delay1,
+		  const Delay &delay2,
+		  const MinMax *min_max,
+		  const StaState *sta)
+{
+  if (min_max == MinMax::max())
+    return delayGreaterEqual(delay1, delay2, sta);
+  else
+    return delayLessEqual(delay1, delay2, sta);
 }
 
 float
@@ -463,6 +416,49 @@ delayAsString(const Delay &delay,
   return sta->units()->timeUnit()->asString(mean_sigma, digits);
 }
 
+Delay
+delayRemove(const Delay &delay1,
+	    const Delay &delay2)
+{
+  return Delay(delay1.mean() - delay2.mean(),
+	       delay1.sigma2Early() - delay2.sigma2Early(),
+	       delay1.sigma2Late() - delay2.sigma2Late());
+}
+
+float
+delayRatio(const Delay &delay1,
+	   const Delay &delay2)
+{
+  return delay1.mean() / delay2.mean();
+}
+
+Delay
+operator+(float delay1,
+	  const Delay &delay2)
+{
+  return Delay(delay1 + delay2.mean(),
+	       delay2.sigma2Early(),
+	       delay2.sigma2Late());
+}
+
+Delay
+operator/(float delay1,
+	  const Delay &delay2)
+{
+  return Delay(delay1 / delay2.mean(),
+	       delay2.sigma2Early(),
+	       delay2.sigma2Late());
+}
+
+Delay
+operator*(const Delay &delay1,
+	  float delay2)
+{
+  return Delay(delay1.mean() * delay2,
+	       delay1.sigma2Early() * delay2 * delay2,
+	       delay1.sigma2Late() * delay2 * delay2);
+}
+
 } // namespace
 
 #endif // (SSTA == 2)
diff --git a/include/sta/Clock.hh b/include/sta/Clock.hh
index d38c65ee..33d48898 100644
--- a/include/sta/Clock.hh
+++ b/include/sta/Clock.hh
@@ -294,12 +294,4 @@ void
 sortClockSet(ClockSet * set,
 	     ClockSeq &clks);
 
-// Clock source pins.
-class ClockPinIterator : public PinSet::Iterator
-{
-public:
-  // Use range iterator on Clock::pins().
-  ClockPinIterator(Clock *clk) __attribute__ ((deprecated));
-};
-
 } // namespace
diff --git a/include/sta/Debug.hh b/include/sta/Debug.hh
index eb70468a..22c57794 100644
--- a/include/sta/Debug.hh
+++ b/include/sta/Debug.hh
@@ -17,6 +17,7 @@
 #pragma once
 
 #include <stdarg.h>
+#include "Machine.hh"
 #include "DisallowCopyAssign.hh"
 #include "Map.hh"
 #include "StringUtil.hh"
diff --git a/include/sta/Delay.hh b/include/sta/Delay.hh
index 06ca2929..5b68ae8c 100644
--- a/include/sta/Delay.hh
+++ b/include/sta/Delay.hh
@@ -14,10 +14,10 @@
 // You should have received a copy of the GNU General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-#include "StaConfig.hh"
-
 #pragma once
 
+#include "StaConfig.hh"
+
 #if (SSTA == 1)
   // Delays are Normal PDFs.
   #include "DelayNormal1.hh"
diff --git a/include/sta/DelayFloat.hh b/include/sta/DelayFloat.hh
index 70bd51f1..58987103 100644
--- a/include/sta/DelayFloat.hh
+++ b/include/sta/DelayFloat.hh
@@ -17,7 +17,6 @@
 #pragma once
 
 #include "MinMax.hh"
-#include "Fuzzy.hh"
 
 // Delay values defined as floats.
 
@@ -32,6 +31,19 @@ const Delay delay_zero = 0.0;
 void
 initDelayConstants();
 
+const char *
+delayAsString(const Delay &delay,
+	      const StaState *sta);
+const char *
+delayAsString(const Delay &delay,
+	      const StaState *sta,
+	      int digits);
+const char *
+delayAsString(const Delay &delay,
+	      const EarlyLate *early_late,
+	      const StaState *sta,
+	      int digits);
+
 inline Delay
 makeDelay(float delay,
 	  float,
@@ -55,47 +67,71 @@ delayAsFloat(const Delay &delay)
 }
 
 // mean late+/early- sigma
-float
+inline float
 delayAsFloat(const Delay &delay,
-	     const EarlyLate *early_late,
-	     const StaState *sta);
-float
-delaySigma2(const Delay &delay,
-	    const EarlyLate *early_late);
-const char *
-delayAsString(const Delay &delay,
-	      const StaState *sta);
-const char *
-delayAsString(const Delay &delay,
-	      const StaState *sta,
-	      int digits);
-const char *
-delayAsString(const Delay &delay,
-	      const EarlyLate *early_late,
-	      const StaState *sta,
-	      int digits);
+	     const EarlyLate *,
+	     const StaState *)
+{
+  return delay;
+}
+
+inline float
+delaySigma2(const Delay &,
+	    const EarlyLate *)
+{
+  return 0.0;
+}
+
 const Delay &
 delayInitValue(const MinMax *min_max);
 bool
 delayIsInitValue(const Delay &delay,
 		 const MinMax *min_max);
 bool
-fuzzyGreater(const Delay &delay1,
-	     const Delay &delay2,
-	     const MinMax *min_max);
+delayZero(const Delay &delay);
 bool
-fuzzyGreaterEqual(const Delay &delay1,
-		  const Delay &delay2,
-		  const MinMax *min_max);
+delayInf(const Delay &delay);
 bool
-fuzzyLess(const Delay &delay1,
+delayEqual(const Delay &delay1,
+	   const Delay &delay2);
+bool
+delayLess(const Delay &delay1,
 	  const Delay &delay2,
-	  const MinMax *min_max);
+	  const StaState *sta);
 bool
-fuzzyLessEqual(const Delay &delay1,
+delayLess(const Delay &delay1,
+	  const Delay &delay2,
+	  const MinMax *min_max,
+	  const StaState *sta);
+bool
+delayLessEqual(const Delay &delay1,
 	       const Delay &delay2,
-	       const MinMax *min_max);
+	       const StaState *sta);
+bool
+delayLessEqual(const Delay &delay1,
+	       const Delay &delay2,
+	       const MinMax *min_max,
+	       const StaState *sta);
+bool
+delayGreater(const Delay &delay1,
+	     const Delay &delay2,
+	     const StaState *sta);
+bool
+delayGreaterEqual(const Delay &delay1,
+		  const Delay &delay2,
+		  const StaState *sta);
+bool
+delayGreaterEqual(const Delay &delay1,
+		  const Delay &delay2,
+		  const MinMax *min_max,
+		  const StaState *sta);
+bool
+delayGreater(const Delay &delay1,
+	     const Delay &delay2,
+	     const MinMax *min_max,
+	     const StaState *sta);
 
+// delay1-delay2 subtracting sigma instead of addiing.
 Delay
 delayRemove(const Delay &delay1,
 	    const Delay &delay2);
diff --git a/include/sta/DelayNormal1.hh b/include/sta/DelayNormal1.hh
index 1b99f139..b25529c7 100644
--- a/include/sta/DelayNormal1.hh
+++ b/include/sta/DelayNormal1.hh
@@ -47,10 +47,6 @@ public:
   void operator-=(float delay);
   void operator-=(const Delay &delay);
   bool operator==(const Delay &delay) const;
-  bool operator>(const Delay &delay) const;
-  bool operator>=(const Delay &delay) const;
-  bool operator<(const Delay &delay) const;
-  bool operator<=(const Delay &delay) const;
 
 private:
   float mean_;
@@ -63,6 +59,19 @@ const Delay delay_zero(0.0);
 void
 initDelayConstants();
 
+const char *
+delayAsString(const Delay &delay,
+	      const StaState *sta);
+const char *
+delayAsString(const Delay &delay,
+	      const StaState *sta,
+	      int digits);
+const char *
+delayAsString(const Delay &delay,
+	      const EarlyLate *early_late,
+	      const StaState *sta,
+	      int digits);
+
 Delay
 makeDelay(float delay,
 	  float sigma_early,
@@ -75,7 +84,10 @@ makeDelay2(float delay,
 	   float sigma_late);
 
 inline float
-delayAsFloat(const Delay &delay) { return delay.mean(); }
+delayAsFloat(const Delay &delay)
+{
+  return delay.mean();
+}
 
 // mean late+/early- sigma
 float
@@ -85,58 +97,55 @@ delayAsFloat(const Delay &delay,
 float
 delaySigma2(const Delay &delay,
 	    const EarlyLate *early_late);
-const char *
-delayAsString(const Delay &delay,
-	      const StaState *sta);
-const char *
-delayAsString(const Delay &delay,
-	      const StaState *sta,
-	      int digits);
-const char *
-delayAsString(const Delay &delay,
-	      const EarlyLate *early_late,
-	      const StaState *sta,
-	      int digits);
 const Delay &
 delayInitValue(const MinMax *min_max);
 bool
 delayIsInitValue(const Delay &delay,
 		 const MinMax *min_max);
 bool
-fuzzyZero(const Delay &delay);
+delayZero(const Delay &delay);
 bool
-fuzzyInf(const Delay &delay);
+delayInf(const Delay &delay);
 bool
-fuzzyEqual(const Delay &delay1,
+delayEqual(const Delay &delay1,
 	   const Delay &delay2);
 bool
-fuzzyLess(const Delay &delay1,
-	  const Delay &delay2);
-bool
-fuzzyLess(const Delay &delay1,
+delayLess(const Delay &delay1,
 	  const Delay &delay2,
-	  const MinMax *min_max);
+	  const StaState *sta);
 bool
-fuzzyLessEqual(const Delay &delay1,
-	       const Delay &delay2);
+delayLess(const Delay &delay1,
+	  const Delay &delay2,
+	  const MinMax *min_max,
+	  const StaState *sta);
 bool
-fuzzyLessEqual(const Delay &delay1,
+delayLessEqual(const Delay &delay1,
 	       const Delay &delay2,
-	       const MinMax *min_max);
+	       const StaState *sta);
 bool
-fuzzyGreater(const Delay &delay1,
-	     const Delay &delay2);
+delayLessEqual(const Delay &delay1,
+	       const Delay &delay2,
+	       const MinMax *min_max,
+	       const StaState *sta);
 bool
-fuzzyGreaterEqual(const Delay &delay1,
-		  const Delay &delay2);
-bool
-fuzzyGreaterEqual(const Delay &delay1,
-		  const Delay &delay2,
-		  const MinMax *min_max);
-bool
-fuzzyGreater(const Delay &delay1,
+delayGreater(const Delay &delay1,
 	     const Delay &delay2,
-	     const MinMax *min_max);
+	     const StaState *sta);
+bool
+delayGreaterEqual(const Delay &delay1,
+		  const Delay &delay2,
+		  const StaState *sta);
+bool
+delayGreaterEqual(const Delay &delay1,
+		  const Delay &delay2,
+		  const MinMax *min_max,
+		  const StaState *sta);
+bool
+delayGreater(const Delay &delay1,
+	     const Delay &delay2,
+	     const MinMax *min_max,
+	     const StaState *sta);
+
 // delay1-delay2 subtracting sigma instead of addiing.
 Delay delayRemove(const Delay &delay1,
 		  const Delay &delay2);
diff --git a/include/sta/DelayNormal2.hh b/include/sta/DelayNormal2.hh
index d39a5ec3..44f3d278 100644
--- a/include/sta/DelayNormal2.hh
+++ b/include/sta/DelayNormal2.hh
@@ -50,10 +50,6 @@ public:
   void operator-=(float delay);
   void operator-=(const Delay &delay);
   bool operator==(const Delay &delay) const;
-  bool operator>(const Delay &delay) const;
-  bool operator>=(const Delay &delay) const;
-  bool operator<(const Delay &delay) const;
-  bool operator<=(const Delay &delay) const;
 
 protected:
   static const int early_index = 0;
@@ -70,28 +66,6 @@ const Delay delay_zero(0.0);
 void
 initDelayConstants();
 
-Delay
-makeDelay(float delay,
-	  float sigma_early,
-	  float sigma_late);
-
-Delay
-makeDelay2(float delay,
-	   // sigma^2
-	   float sigma_early,
-	   float sigma_late);
-
-inline float
-delayAsFloat(const Delay &delay) { return delay.mean(); }
-
-// mean late+/early- sigma
-float
-delayAsFloat(const Delay &delay,
-	     const EarlyLate *early_late,
-	     const StaState *sta);
-float
-delaySigma2(const Delay &delay,
-	    const EarlyLate *early_late);
 const char *
 delayAsString(const Delay &delay,
 	      const StaState *sta);
@@ -104,46 +78,81 @@ delayAsString(const Delay &delay,
 	      const EarlyLate *early_late,
 	      const StaState *sta,
 	      int digits);
+
+Delay
+makeDelay(float delay,
+	  float sigma_early,
+	  float sigma_late);
+
+Delay
+makeDelay2(float delay,
+	   // sigma^2
+	   float sigma_early,
+	   float sigma_late);
+
+inline float
+delayAsFloat(const Delay &delay)
+{
+  return delay.mean();
+}
+
+// mean late+/early- sigma
+float
+delayAsFloat(const Delay &delay,
+	     const EarlyLate *early_late,
+	     const StaState *sta);
+float
+delaySigma2(const Delay &delay,
+	    const EarlyLate *early_late);
 const Delay &
 delayInitValue(const MinMax *min_max);
 bool
 delayIsInitValue(const Delay &delay,
 		 const MinMax *min_max);
 bool
-fuzzyZero(const Delay &delay);
+delayZero(const Delay &delay);
 bool
-fuzzyInf(const Delay &delay);
+delayInf(const Delay &delay);
 bool
-fuzzyEqual(const Delay &delay1,
+delayEqual(const Delay &delay1,
 	   const Delay &delay2);
 bool
-fuzzyLess(const Delay &delay1,
-	  const Delay &delay2);
-bool
-fuzzyLess(const Delay &delay1,
+delayLess(const Delay &delay1,
 	  const Delay &delay2,
-	  const MinMax *min_max);
+	  const StaState *sta);
 bool
-fuzzyLessEqual(const Delay &delay1,
-	       const Delay &delay2);
+delayLess(const Delay &delay1,
+	  const Delay &delay2,
+	  const MinMax *min_max,
+	  const StaState *sta);
 bool
-fuzzyLessEqual(const Delay &delay1,
+delayLessEqual(const Delay &delay1,
 	       const Delay &delay2,
-	       const MinMax *min_max);
+	       const StaState *sta);
 bool
-fuzzyGreater(const Delay &delay1,
-	     const Delay &delay2);
+delayLessEqual(const Delay &delay1,
+	       const Delay &delay2,
+	       const MinMax *min_max,
+	       const StaState *sta);
 bool
-fuzzyGreaterEqual(const Delay &delay1,
-		  const Delay &delay2);
-bool
-fuzzyGreaterEqual(const Delay &delay1,
-		  const Delay &delay2,
-		  const MinMax *min_max);
-bool
-fuzzyGreater(const Delay &delay1,
+delayGreater(const Delay &delay1,
 	     const Delay &delay2,
-	     const MinMax *min_max);
+	     const StaState *sta);
+bool
+delayGreaterEqual(const Delay &delay1,
+		  const Delay &delay2,
+		  const StaState *sta);
+bool
+delayGreaterEqual(const Delay &delay1,
+		  const Delay &delay2,
+		  const MinMax *min_max,
+		  const StaState *sta);
+bool
+delayGreater(const Delay &delay1,
+	     const Delay &delay2,
+	     const MinMax *min_max,
+	     const StaState *sta);
+
 // delay1-delay2 subtracting sigma instead of addiing.
 Delay delayRemove(const Delay &delay1,
 		  const Delay &delay2);
diff --git a/include/sta/Liberty.hh b/include/sta/Liberty.hh
index 5818e4bb..ec898916 100644
--- a/include/sta/Liberty.hh
+++ b/include/sta/Liberty.hh
@@ -493,6 +493,7 @@ public:
 	      Report *report,
 	      Debug *debug);
   bool isBuffer() const;
+  bool isInverter() const;
   // Only valid when isBuffer() returns true.
   void bufferPorts(// Return values.
 		   LibertyPort *&input,
@@ -522,6 +523,8 @@ protected:
   void makeTimingArcPortMaps();
   bool hasBufferFunc(const LibertyPort *input,
 		     const LibertyPort *output) const;
+  bool hasInverterFunc(const LibertyPort *input,
+		       const LibertyPort *output) const;
 
   LibertyLibrary *liberty_library_;
   float area_;
@@ -633,6 +636,7 @@ public:
 		  float &fanout_load,
 		  bool &exists) const;
   void setFanoutLoad(float fanout_load);
+  float capacitance() const;
   float capacitance(const RiseFall *rf,
 		    const MinMax *min_max) const;
   void capacitance(const RiseFall *rf,
diff --git a/util/Machine.hh b/include/sta/Machine.hh
similarity index 100%
rename from util/Machine.hh
rename to include/sta/Machine.hh
diff --git a/include/sta/Network.hh b/include/sta/Network.hh
index 4a6e092e..eab973ad 100644
--- a/include/sta/Network.hh
+++ b/include/sta/Network.hh
@@ -323,6 +323,13 @@ public:
   virtual VertexId vertexId(const Pin *pin) const = 0;
   virtual void setVertexId(Pin *pin,
 			   VertexId id) = 0;
+  // Return the physical X/Y coordinates of the pin.
+  virtual void location(const Pin *pin,
+			// Return values.
+			double &x,
+			double &y,
+			bool &exists) const;
+
   int pinCount();
   int pinCount(Instance *inst);
   int leafPinCount();
diff --git a/include/sta/PathEnd.hh b/include/sta/PathEnd.hh
index c60d8fdc..82e16883 100644
--- a/include/sta/PathEnd.hh
+++ b/include/sta/PathEnd.hh
@@ -142,6 +142,7 @@ public:
   virtual TimingArc *checkArc() const { return nullptr; }
   // PathEndDataCheck data clock path.
   virtual const PathVertex *dataClkPath() const { return nullptr; }
+  virtual int setupDefaultCycles() const { return 1; }
 
   static bool less(const PathEnd *path_end1,
 		   const PathEnd *path_end2,
@@ -181,6 +182,7 @@ public:
   static float checkSetupMcpAdjustment(const ClockEdge *src_clk_edge,
 				       const ClockEdge *tgt_clk_edge,
 				       const MultiCyclePath *mcp,
+				       int default_cycles,
 				       Sdc *sdc);
 
 protected:
@@ -425,6 +427,7 @@ private:
 
 // Path constrained by an output delay.
 // If there is a reference pin, clk_path_ is the reference pin clock.
+// If there is a path delay PathEndPathDelay is used instead of this.
 class PathEndOutputDelay : public PathEndClkConstrainedMcp
 {
 public:
@@ -544,6 +547,8 @@ protected:
 		   Crpr crpr,
 		   bool crpr_valid);
   Arrival requiredTimeNoCrpr(const StaState *sta) const;
+  // setup uses zero cycle default
+  virtual int setupDefaultCycles() const { return 0; }
 
 private:
   PathVertex data_clk_path_;
@@ -555,6 +560,7 @@ private:
 
 // Path constrained by set_min/max_delay.
 // "Clocked" when path delay ends at timing check pin.
+// May end at output with set_output_delay.
 class PathEndPathDelay : public PathEndClkConstrained
 {
 public:
@@ -587,6 +593,7 @@ public:
   virtual PathDelay *pathDelay() const { return path_delay_; }
   virtual ArcDelay margin(const StaState *sta) const;
   virtual float sourceClkOffset(const StaState *sta) const;
+  virtual ClockEdge *targetClkEdge(const StaState *sta) const;
   virtual float targetClkTime(const StaState *sta) const;
   virtual Arrival targetClkArrivalNoCrpr(const StaState *sta) const;
   virtual float targetClkOffset(const StaState *sta) const;
@@ -594,6 +601,7 @@ public:
   virtual Required requiredTime(const StaState *sta) const;
   virtual int exceptPathCmp(const PathEnd *path_end,
 			    const StaState *sta) const;
+  bool hasOutputDelay() const { return output_delay_ != nullptr; }
 
 protected:
   PathEndPathDelay(PathDelay *path_delay,
@@ -610,8 +618,7 @@ protected:
   PathDelay *path_delay_;
   TimingArc *check_arc_;
   Edge *check_edge_;
-  // Output delay is nullptr when there is no timing check or output
-  // delay at the endpoint.
+  // Output delay is nullptr when there is no output delay at the endpoint.
   OutputDelay *output_delay_;
   // Source clk arrival for set_min/max_delay -ignore_clk_latency.
   Arrival src_clk_arrival_;
diff --git a/include/sta/PowerClass.hh b/include/sta/PowerClass.hh
new file mode 100644
index 00000000..706e1f45
--- /dev/null
+++ b/include/sta/PowerClass.hh
@@ -0,0 +1,73 @@
+// OpenSTA, Static Timing Analyzer
+// Copyright (c) 2020, Parallax Software, Inc.
+// 
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+// 
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+// 
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+#pragma once
+
+namespace sta {
+
+enum class PwrActivityOrigin
+{
+ global,
+ input,
+ user,
+ propagated,
+ clock,
+ constant,
+ defaulted,
+ unknown
+};
+
+class PwrActivity
+{
+public:
+  PwrActivity();
+  PwrActivity(float activity,
+		float duty,
+		PwrActivityOrigin origin);
+  float activity() const { return activity_; }
+  float duty() const { return duty_; }
+  PwrActivityOrigin origin() { return origin_; }
+  const char *originName() const;
+  void set(float activity,
+	   float duty,
+	   PwrActivityOrigin origin);
+  bool isSet() const;
+
+private:
+  // In general activity is per clock cycle, NOT per second.
+  float activity_;
+  float duty_;
+  PwrActivityOrigin origin_;
+};
+
+class PowerResult
+{
+public:
+  PowerResult();
+  void clear();
+  float &internal() { return internal_; }
+  float &switching() { return switching_; }
+  float &leakage() { return leakage_; }
+  float total() const;
+  void incr(PowerResult &result);
+  
+private:
+  float internal_;
+  float switching_;
+  float leakage_;
+};
+
+} // namespace
diff --git a/include/sta/Property.hh b/include/sta/Property.hh
index c83f1af1..d4b35bee 100644
--- a/include/sta/Property.hh
+++ b/include/sta/Property.hh
@@ -22,7 +22,7 @@
 #include "NetworkClass.hh"
 #include "SearchClass.hh"
 #include "SdcClass.hh"
-#include "Power.hh"
+#include "PowerClass.hh"
 
 namespace sta {
 
diff --git a/include/sta/Report.hh b/include/sta/Report.hh
index 6dd0ca47..df45765d 100644
--- a/include/sta/Report.hh
+++ b/include/sta/Report.hh
@@ -20,6 +20,7 @@
 #include <stdarg.h>
 #include <string>
 #include <mutex>
+#include "Machine.hh"
 #include "DisallowCopyAssign.hh"
 
 struct Tcl_Interp;
diff --git a/include/sta/RiseFallMinMax.hh b/include/sta/RiseFallMinMax.hh
index 57f2900d..69711fe4 100644
--- a/include/sta/RiseFallMinMax.hh
+++ b/include/sta/RiseFallMinMax.hh
@@ -36,6 +36,9 @@ public:
 	     float &value,
 	     bool &exists) const;
   bool hasValue() const;
+  void maxValue(// Return values
+		float &max_value,
+		bool &exists) const;
   bool empty() const;
   bool hasValue(const RiseFall *rf,
 		const MinMax *min_max) const;
diff --git a/include/sta/Sdc.hh b/include/sta/Sdc.hh
index 560fddbe..03dd6513 100644
--- a/include/sta/Sdc.hh
+++ b/include/sta/Sdc.hh
@@ -824,7 +824,6 @@ public:
   // Find the clocks defined for pin.
   ClockSet *findClocks(const Pin *pin) const;
   ClockSet *findLeafPinClocks(const Pin *pin) const;
-  ClockIterator *clockIterator() __attribute__ ((deprecated));
   void sortedClocks(ClockSeq &clks);
   ClockSeq *clocks() { return &clocks_; }
   ClockSeq &clks() { return clocks_; }
@@ -990,11 +989,8 @@ public:
   void deleteException(ExceptionPath *exception);
   void recordException(ExceptionPath *exception);
   void unrecordException(ExceptionPath *exception);
-  // Annotate graph from constraints.  If the graph exists when the
-  // constraints are defined it is annotated incrementally.  This is
-  // called after building the graph to annotate any constraints that
-  // were defined before the graph is built.
-  void annotateGraph(bool annotate);
+  void annotateGraph();
+  void removeGraphAnnotations();
 
   // Network edit before/after methods.
   void disconnectPinBefore(Pin *pin);
@@ -1180,34 +1176,25 @@ protected:
   // Liberty library to look for defaults.
   LibertyLibrary *defaultLibertyLibrary();
   void annotateGraphConstrainOutputs();
-  void annotateDisables(bool annotate);
-  void annotateGraphDisabled(const Pin *pin,
-			     bool annotate);
-  void setEdgeDisabledInstPorts(DisabledInstancePorts *disabled_inst,
-				bool annotate);
+  void annotateDisables();
+  void annotateGraphDisabled(const Pin *pin);
+  void setEdgeDisabledInstPorts(DisabledInstancePorts *disabled_inst);
   void setEdgeDisabledInstFrom(Pin *from_pin,
-			       bool disable_checks,
-			       bool annotate);
+			       bool disable_checks);
   void setEdgeDisabledInstPorts(DisabledPorts *disabled_port,
-				Instance *inst,
-				bool annotate);
+				Instance *inst);
   void deleteClockLatenciesReferencing(Clock *clk);
   void deleteClockLatency(ClockLatency *latency);
   void deleteDeratingFactors();
-  void annotateGraphOutputDelays(bool annotate);
-  void annotateGraphDataChecks(bool annotate);
-  void annotateGraphConstrained(const PinSet *pins,
-				bool annotate);
-  void annotateGraphConstrained(const InstanceSet *insts,
-				bool annotate);
-  void annotateGraphConstrained(const Instance *inst,
-				bool annotate);
-  void annotateGraphConstrained(const Pin *pin,
-				bool annotate);
-  void annotateHierClkLatency(bool annotate);
+  void annotateGraphOutputDelays();
+  void annotateGraphDataChecks();
+  void annotateGraphConstrained(const PinSet *pins);
+  void annotateGraphConstrained(const InstanceSet *insts);
+  void annotateGraphConstrained(const Instance *inst);
+  void annotateGraphConstrained(const Pin *pin);
+  void annotateHierClkLatency();
   void annotateHierClkLatency(const Pin *hpin,
 			      ClockLatency *latency);
-  void deannotateHierClkLatency(const Pin *hpin);
   void initInstancePvtMaps();
   void pinCaps(const Pin *pin,
 	       const RiseFall *rf,
@@ -1257,9 +1244,6 @@ protected:
   void disconnectPinBefore(Pin *pin,
 			   ExceptionPathSet *exceptions);
   void clockGroupsDeleteClkRefs(Clock *clk);
-  void makeVertexClkHpinDisables(Clock *clk,
-				 Vertex *vertex,
-				 FindClkHpinDisables &visitor);
   void clearGroupPathMap();
 
   AnalysisType analysis_type_;
diff --git a/include/sta/SdcNetwork.hh b/include/sta/SdcNetwork.hh
index 6172a17d..d5aece26 100644
--- a/include/sta/SdcNetwork.hh
+++ b/include/sta/SdcNetwork.hh
@@ -103,6 +103,11 @@ public:
   virtual VertexId vertexId(const Pin *pin) const;
   virtual void setVertexId(Pin *pin,
 			   VertexId id);
+  virtual void location(const Pin *pin,
+			// Return values.
+			double &x,
+			double &y,
+			bool &exists) const;
 
   virtual Net *net(const Term *term) const;
   virtual Pin *pin(const Term *term) const;
@@ -120,7 +125,6 @@ public:
   virtual char pathEscape() const;
   virtual void setPathEscape(char escape);
 
-
   virtual bool isEditable() const;
   virtual LibertyLibrary *makeLibertyLibrary(const char *name,
 					     const char *filename);
diff --git a/include/sta/Search.hh b/include/sta/Search.hh
index 09929e3c..18efcf20 100644
--- a/include/sta/Search.hh
+++ b/include/sta/Search.hh
@@ -752,7 +752,8 @@ public:
 		     const StaState *sta);
   void requiredSet(int arrival_index,
 		   Required required,
-		   const MinMax *min_max);
+		   const MinMax *min_max,
+		   const StaState *sta);
   // Return true if the requireds changed.
   bool requiredsSave(Vertex *vertex,
 		     const StaState *sta);
diff --git a/include/sta/SearchClass.hh b/include/sta/SearchClass.hh
index 2eaae23c..c6f49dd3 100644
--- a/include/sta/SearchClass.hh
+++ b/include/sta/SearchClass.hh
@@ -119,7 +119,8 @@ enum class ReportPathFormat { full,
 			      shorter,
 			      endpoint,
 			      summary,
-			      slack_only
+			      slack_only,
+			      json
 };
 
 static const int tag_index_bits = 24;
diff --git a/include/sta/Sta.hh b/include/sta/Sta.hh
index 150d9610..af0b67e1 100644
--- a/include/sta/Sta.hh
+++ b/include/sta/Sta.hh
@@ -18,6 +18,7 @@
 
 #include <string>
 
+#include "Machine.hh"
 #include "DisallowCopyAssign.hh"
 #include "StringSeq.hh"
 #include "LibertyClass.hh"
@@ -28,6 +29,7 @@
 #include "StaState.hh"
 #include "VertexVisitor.hh"
 #include "SearchClass.hh"
+#include "PowerClass.hh"
 
 struct Tcl_Interp;
 
@@ -292,17 +294,8 @@ public:
   void removeClock(Clock *clk);
   // Update period/waveform for generated clocks from source pin clock.
   void updateGeneratedClks();
-  // Use Sdc::findClock
-  Clock *findClock(const char *name) const __attribute__ ((deprecated));
-  // Use findClocksMatching.
-  void findClocksMatching(PatternMatch *pattern,
-			  ClockSeq *clks) const __attribute__ ((deprecated));
-  // Use Sdc::clockIterator.
-  ClockIterator *clockIterator() const __attribute__ ((deprecated));
   // True if pin is defined as a clock source (pin may be hierarchical).
   bool isClockSrc(const Pin *pin) const;
-  // Use Sdc::defaultArrivalClock.
-  Clock *defaultArrivalClock() const __attribute__ ((deprecated));
   // Propagated (non-ideal) clocks.
   void setPropagatedClock(Clock *clk);
   void removePropagatedClock(Clock *clk);
@@ -873,42 +866,6 @@ public:
 				   bool removal,
 				   bool clk_gating_setup,
 				   bool clk_gating_hold);
-  PathEndSeq *reportTiming(ExceptionFrom *from,
-			   ExceptionThruSeq *thrus,
-			   ExceptionTo *to,
-			   // Use corner nullptr to report timing
-			   // for all corners.
-			   const Corner *corner,
-			   // max for setup checks.
-			   // min for hold checks.
-			   // min_max for setup and hold checks.
-			   const MinMaxAll *min_max,
-			   // Number of path ends to report in
-			   // each group.
-			   int group_count,
-			   // Number of paths to report for
-			   // each endpoint.
-			   int endpoint_count,
-			   // endpoint_count paths report unique pins
-			   // without rise/fall variations.
-			   bool unique_pins,
-			   // Min/max bounds for slack of
-			   // returned path ends.
-			   float slack_min,
-			   float slack_max,
-			   // Sort path ends by slack ignoring path groups.
-			   bool sort_by_slack,
-			   // Path groups to report.
-			   // Null or empty list reports all groups.
-			   PathGroupNameSet *group_names,
-			   // Predicates to filter the type of path
-			   // ends returned.
-			   bool setup,
-			   bool hold,
-			   bool recovery,
-			   bool removal,
-			   bool clk_gating_setup,
-			   bool clk_gating_hold) __attribute__ ((deprecated));
   void setReportPathFormat(ReportPathFormat format);
   void setReportPathFieldOrder(StringSeq *field_names);
   void setReportPathFields(bool report_input_pin,
@@ -947,7 +904,6 @@ public:
   void delaysInvalid();
   // Invalidate all arrival and required times.
   void arrivalsInvalid();
-  void setPathMinMax(const MinMaxAll *min_max) __attribute__ ((deprecated));
   void visitStartpoints(VertexVisitor *visitor);
   void visitEndpoints(VertexVisitor *visitor);
   // Find the fanin vertices for a group path.
@@ -1379,6 +1335,8 @@ protected:
   void findClkPins();
   void findClkPins(bool ideal_only,
 		   PinSet &clk_pins);
+  void sdcChangedGraph();
+  void ensureGraphSdcAnnotated();
 
   CmdNamespace cmd_namespace_;
   Instance *current_instance_;
@@ -1397,6 +1355,7 @@ protected:
   bool link_make_black_boxes_;
   bool update_genclks_;
   EquivCells *equiv_cells_;
+  bool graph_sdc_annotated_;
   // findClkPins
   PinSet clk_pins_;
   PinSet ideal_clk_pins_;
diff --git a/include/sta/StringUtil.hh b/include/sta/StringUtil.hh
index 5cfc650a..d06eef34 100644
--- a/include/sta/StringUtil.hh
+++ b/include/sta/StringUtil.hh
@@ -19,6 +19,7 @@
 #include <stdarg.h>
 #include <string.h>
 #include <string>
+#include "Machine.hh"
 #include "Vector.hh"
 
 namespace sta {
diff --git a/include/sta/TimingArc.hh b/include/sta/TimingArc.hh
index ce1a2fc9..00cea66b 100644
--- a/include/sta/TimingArc.hh
+++ b/include/sta/TimingArc.hh
@@ -16,6 +16,7 @@
 
 #pragma once
 
+#include "Machine.hh"
 #include "DisallowCopyAssign.hh"
 #include "Vector.hh"
 #include "Transition.hh"
diff --git a/include/sta/VerilogWriter.hh b/include/sta/VerilogWriter.hh
index 0c877195..163e5f38 100644
--- a/include/sta/VerilogWriter.hh
+++ b/include/sta/VerilogWriter.hh
@@ -16,13 +16,19 @@
 
 #pragma once
 
+#include <vector>
+
 namespace sta {
 
+using std::vector;
+
 class Network;
+class LibertyCell;
 
 void
 writeVerilog(const char *filename,
 	     bool sort,
+	     vector<LibertyCell*> *remove_cells,
 	     Network *network);
 
 } // namespace
diff --git a/liberty/Liberty.cc b/liberty/Liberty.cc
index 38a64706..11c9c317 100644
--- a/liberty/Liberty.cc
+++ b/liberty/Liberty.cc
@@ -1064,6 +1064,27 @@ LibertyCell::hasBufferFunc(const LibertyPort *input,
     && func->port() == input;
 }
 
+bool
+LibertyCell::isInverter() const
+{
+  LibertyPort *input;
+  LibertyPort *output;
+  bufferPorts(input, output);
+  return input && output
+    && hasInverterFunc(input, output);
+}
+
+bool
+LibertyCell::hasInverterFunc(const LibertyPort *input,
+			     const LibertyPort *output) const
+{
+  FuncExpr *func = output->function();
+  return func
+    && func->op() == FuncExpr::op_not
+    && func->left()->op() == FuncExpr::op_port
+    && func->left()->port() == input;
+}
+
 void
 LibertyCell::bufferPorts(// Return values.
 			 LibertyPort *&input,
@@ -1907,6 +1928,18 @@ LibertyPort::setCapacitance(const RiseFall *rf,
   }
 }
 
+float
+LibertyPort::capacitance() const
+{
+  float cap;
+  bool exists;
+  capacitance_.maxValue(cap, exists);
+  if (exists)
+    return cap;
+  else
+    return 0.0;
+}
+
 float
 LibertyPort::capacitance(const RiseFall *rf,
 			 const MinMax *min_max) const
diff --git a/liberty/LibertyExpr.cc b/liberty/LibertyExpr.cc
index 60ce4f55..4933cad9 100644
--- a/liberty/LibertyExpr.cc
+++ b/liberty/LibertyExpr.cc
@@ -16,6 +16,7 @@
 
 #include "FuncExpr.hh"
 
+#include <algorithm> // min
 #include "Report.hh"
 #include "StringUtil.hh"
 #include "Liberty.hh"
@@ -129,14 +130,9 @@ LibExprParser::copyInput(char *buf,
 {
   size_t length = strlen(func_);
   if (length == 0)
-	return 0;
+    return 0;
   else {
-    size_t count;
-
-    if (length < max_size)
-      count = length;
-    else
-      count = max_size;
+    size_t count = std::min(length,  max_size);
     strncpy(buf, func_, count);
     func_ += count;
     return count;
diff --git a/liberty/LibertyReaderPvt.hh b/liberty/LibertyReaderPvt.hh
index 2a356a61..26dffdcc 100644
--- a/liberty/LibertyReaderPvt.hh
+++ b/liberty/LibertyReaderPvt.hh
@@ -18,6 +18,7 @@
 
 #include <functional>
 
+#include "Machine.hh"
 #include "DisallowCopyAssign.hh"
 #include "Vector.hh"
 #include "Map.hh"
diff --git a/network/Network.cc b/network/Network.cc
index 8ac29711..412afcfb 100644
--- a/network/Network.cc
+++ b/network/Network.cc
@@ -935,6 +935,17 @@ Network::findInstPinsMatching(const Instance *instance,
   }
 }
 
+void
+Network::location(const Pin *pin,
+		  // Return values.
+		  double &x,
+		  double &y,
+		  bool &exists) const
+{
+  x = y = 0.0;
+  exists = false;
+}
+
 int
 Network::instanceCount(Instance *inst)
 {
diff --git a/network/SdcNetwork.cc b/network/SdcNetwork.cc
index f8b4de73..707687f3 100644
--- a/network/SdcNetwork.cc
+++ b/network/SdcNetwork.cc
@@ -223,6 +223,16 @@ NetworkNameAdapter::setVertexId(Pin *pin,
   network_->setVertexId(pin, id);
 }
 
+void
+NetworkNameAdapter::location(const Pin *pin,
+			     // Return values.
+			     double &x,
+			     double &y,
+			     bool &exists) const
+{
+  network_->location(pin, x, y, exists);
+}
+
 bool
 NetworkNameAdapter::isBundle(const Port *port) const
 {
diff --git a/parasitics/SpefReaderPvt.hh b/parasitics/SpefReaderPvt.hh
index 3008230a..41a9cfd6 100644
--- a/parasitics/SpefReaderPvt.hh
+++ b/parasitics/SpefReaderPvt.hh
@@ -16,6 +16,7 @@
 
 #pragma once
 
+#include "Machine.hh"
 #include "Zlib.hh"
 #include "Map.hh"
 #include "StringSeq.hh"
diff --git a/sdc/Clock.cc b/sdc/Clock.cc
index 51a991a5..04cf3bbb 100644
--- a/sdc/Clock.cc
+++ b/sdc/Clock.cc
@@ -699,9 +699,4 @@ sortClockSet(ClockSet *set,
   sort(clks, ClockNameLess());
 }
 
-ClockPinIterator::ClockPinIterator(Clock *clk) :
-  PinSet::Iterator(clk->pins())
-{
-}
-
 } // namespace
diff --git a/sdc/RiseFallMinMax.cc b/sdc/RiseFallMinMax.cc
index 47e66a28..35c95b23 100644
--- a/sdc/RiseFallMinMax.cc
+++ b/sdc/RiseFallMinMax.cc
@@ -163,6 +163,23 @@ RiseFallMinMax::hasValue() const
   return !empty();
 }
 
+void
+RiseFallMinMax::maxValue(// Return values
+			 float &max_value,
+			 bool &exists) const
+{
+  max_value = MinMax::max()->initValue();
+  exists = false;
+  for (int rf_index=0;rf_index<RiseFall::index_count;rf_index++) {
+    for (int mm_index = 0; mm_index < MinMax::index_count; mm_index++) {
+      if (exists_[rf_index][mm_index]) {
+	max_value = std::max(max_value, values_[rf_index][mm_index]);
+	exists = true;
+      }
+    }
+  }
+}
+
 bool
 RiseFallMinMax::empty() const
 {
diff --git a/sdc/Sdc.cc b/sdc/Sdc.cc
index cdf5e7b5..9d2839b1 100644
--- a/sdc/Sdc.cc
+++ b/sdc/Sdc.cc
@@ -31,7 +31,6 @@
 #include "Transition.hh"
 #include "PortDirection.hh"
 #include "Network.hh"
-#include "HpinDrvrLoad.hh"
 #include "RiseFallMinMax.hh"
 #include "Clock.hh"
 #include "ClockLatency.hh"
@@ -46,9 +45,10 @@
 #include "ClockGatingCheck.hh"
 #include "ClockGroups.hh"
 #include "DeratingFactors.hh"
-#include "Graph.hh"
+#include "HpinDrvrLoad.hh"
 #include "search/Levelize.hh"
 #include "Corner.hh"
+#include "Graph.hh"
 
 namespace sta {
 
@@ -77,11 +77,6 @@ typedef Set<Pvt*> PvtSet;
 static ExceptionThruSeq *
 clone(ExceptionThruSeq *thrus,
       Network *network);
-static void
-annotateGraphDisabledWireEdge(Pin *from_pin,
-			      Pin *to_pin,
-			      bool annotate,
-			      Graph *graph);
 
 ////////////////////////////////////////////////////////////////
 
@@ -409,15 +404,6 @@ Sdc::initInstancePvtMaps()
 
 ////////////////////////////////////////////////////////////////
 
-void
-Sdc::searchPreamble()
-{
-  ensureClkHpinDisables();
-  ensureClkGroupExclusions();
-}
-
-////////////////////////////////////////////////////////////////
-
 bool
 Sdc::isConstrained(const Pin *pin) const
 {
@@ -1254,12 +1240,6 @@ Sdc::findClocksMatching(PatternMatch *pattern,
   }
 }
 
-ClockIterator *
-Sdc::clockIterator()
-{
-  return new ClockIterator(clocks_);
-}
-
 void
 Sdc::sortedClocks(ClockSeq &clks)
 {
@@ -1398,18 +1378,6 @@ FindClkHpinDisables::drvrLoadExists(Pin *drvr,
   return drvr_loads_.hasKey(&probe);
 }
 
-void
-Sdc::makeClkHpinDisable(Clock *clk,
-			Pin *drvr,
-			Pin *load)
-{
-  ClkHpinDisable probe(clk, drvr, load);
-  if (!clk_hpin_disables_.hasKey(&probe)) {
-    ClkHpinDisable *disable = new ClkHpinDisable(clk, drvr, load);
-    clk_hpin_disables_.insert(disable);
-  }
-}
-
 void
 Sdc::ensureClkHpinDisables()
 {
@@ -1418,16 +1386,20 @@ Sdc::ensureClkHpinDisables()
     for (auto clk : clocks_) {
       for (Pin *src : clk->pins()) {
 	if (network_->isHierarchical(src)) {
-	  FindClkHpinDisables visitor(clk, network_, this);
-	  visitHpinDrvrLoads(src, network_, &visitor);
+	  FindClkHpinDisables visitor1(clk, network_, this);
+	  visitHpinDrvrLoads(src, network_, &visitor1);
+	  PinSeq loads, drvrs;
+	  PinSet visited_drvrs;
+	  FindNetDrvrLoads visitor2(nullptr, visited_drvrs, loads, drvrs, network_);
+	  network_->visitConnectedPins(src, visitor2);
+
 	  // Disable fanouts from the src driver pins that do
 	  // not go thru the hierarchical src pin.
-	  for (Pin *lpin : clk->leafPins()) {
-	    Vertex *vertex, *bidirect_drvr_vertex;
-	    graph_->pinVertices(lpin, vertex, bidirect_drvr_vertex);
-	    makeVertexClkHpinDisables(clk, vertex, visitor);
-	    if (bidirect_drvr_vertex)
-	      makeVertexClkHpinDisables(clk, bidirect_drvr_vertex, visitor);
+	  for (Pin *drvr : drvrs) {
+	    for (Pin *load : loads) {
+	      if (!visitor1.drvrLoadExists(drvr, load))
+		makeClkHpinDisable(clk, drvr, load);
+	    }
 	  }
 	}
       }
@@ -1437,19 +1409,14 @@ Sdc::ensureClkHpinDisables()
 }
 
 void
-Sdc::makeVertexClkHpinDisables(Clock *clk,
-			       Vertex *vertex,
-			       FindClkHpinDisables &visitor)
+Sdc::makeClkHpinDisable(Clock *clk,
+			Pin *drvr,
+			Pin *load)
 {
-  VertexOutEdgeIterator edge_iter(vertex, graph_);
-  while (edge_iter.hasNext()) {
-    Edge *edge = edge_iter.next();
-    if (edge->isWire()) {
-      Pin *drvr = edge->from(graph_)->pin();
-      Pin *load = edge->to(graph_)->pin();
-      if (!visitor.drvrLoadExists(drvr, load))
-	makeClkHpinDisable(clk, drvr, load);
-    }
+  ClkHpinDisable probe(clk, drvr, load);
+  if (!clk_hpin_disables_.hasKey(&probe)) {
+    ClkHpinDisable *disable = new ClkHpinDisable(clk, drvr, load);
+    clk_hpin_disables_.insert(disable);
   }
 }
 
@@ -1539,8 +1506,6 @@ Sdc::setClockLatency(Clock *clk,
     clk_latencies_.insert(latency);
   }
   latency->setDelay(rf, min_max, delay);
-  if (pin && graph_ && network_->isHierarchical(pin))
-    annotateHierClkLatency(pin, latency);
 
   // set_clock_latency removes set_propagated_clock on the same object.
   if (clk && pin == nullptr)
@@ -1563,8 +1528,6 @@ void
 Sdc::deleteClockLatency(ClockLatency *latency)
 {
   const Pin *pin = latency->pin();
-  if (pin && graph_ && network_->isHierarchical(pin))
-    deannotateHierClkLatency(pin);
   clk_latencies_.erase(latency);
   delete latency;
 }
@@ -2530,9 +2493,6 @@ Sdc::setDataCheck(Pin *from,
     data_checks_to_map_[to] = checks;
   }
   checks->insert(check);
-
-  if (graph_)
-    annotateGraphConstrained(to, true);
 }
 
 void
@@ -2966,8 +2926,6 @@ Sdc::makeOutputDelay(Pin *pin,
       output_delay_leaf_pin_map_[lpin] = leaf_outputs;
     }
     leaf_outputs->insert(output_delay);
-    if (graph_)
-      annotateGraphConstrained(lpin, true);
   }
   return output_delay;
 }
@@ -3591,19 +3549,11 @@ void
 Sdc::disable(Port *port)
 {
   disabled_ports_.insert(port);
-  if (graph_) {
-    Pin *pin = network_->findPin(network_->topInstance(), port);
-    annotateGraphDisabled(pin, true);
-  }
 }
 
 void
 Sdc::removeDisable(Port *port)
 {
-  if (graph_) {
-    Pin *pin = network_->findPin(network_->topInstance(), port);
-    annotateGraphDisabled(pin, false);
-  }
   disabled_ports_.erase(port);
 }
 
@@ -3625,9 +3575,6 @@ Sdc::disable(Instance *inst,
     disabled_inst->setDisabledTo(to);
   else
     disabled_inst->setDisabledAll();
-
-  if (graph_)
-    setEdgeDisabledInstPorts(disabled_inst, true);
 }
 
 void
@@ -3637,8 +3584,6 @@ Sdc::removeDisable(Instance *inst,
 {
   DisabledInstancePorts *disabled_inst = disabled_inst_ports_.findKey(inst);
   if (disabled_inst) {
-    if (graph_)
-      setEdgeDisabledInstPorts(disabled_inst, false);
     if (from && to)
       disabled_inst->removeDisabledFromTo(from, to);
     else if (from)
@@ -3658,8 +3603,6 @@ Sdc::disable(Pin *from,
   if (!disabled_wire_edges_.hasKey(&probe)) {
     PinPair *pair = new PinPair(from, to);
     disabled_wire_edges_.insert(pair);
-    if (graph_)
-      annotateGraphDisabledWireEdge(from, to, true, graph_);
   }
 }
 
@@ -3667,7 +3610,6 @@ void
 Sdc::removeDisable(Pin *from,
 		   Pin *to)
 {
-  annotateGraphDisabledWireEdge(from, to, false, graph_);
   PinPair probe(from, to);
   disabled_wire_edges_.erase(&probe);
 }
@@ -3725,8 +3667,6 @@ DisableEdgesThruHierPin::visit(Pin *drvr,
   if (!pairs_->hasKey(&probe)) {
     PinPair *pair = new PinPair(drvr, load);
     pairs_->insert(pair);
-    if (graph_)
-      annotateGraphDisabledWireEdge(drvr, load, true, graph_);
   }
 }
 
@@ -3738,17 +3678,15 @@ Sdc::disable(Pin *pin)
     DisableEdgesThruHierPin visitor(&disabled_wire_edges_, graph_);
     visitDrvrLoadsThruHierPin(pin, network_, &visitor);
   }
-  else {
+  else
     disabled_pins_.insert(pin);
-    if (graph_)
-      annotateGraphDisabled(pin, true);
-  }
 }
 
 class RemoveDisableEdgesThruHierPin : public HierPinThruVisitor
 {
 public:
-  RemoveDisableEdgesThruHierPin(PinPairSet *pairs, Graph *graph);
+  RemoveDisableEdgesThruHierPin(PinPairSet *pairs,
+				Graph *graph);
 
 protected:
   virtual void visit(Pin *drvr, Pin *load);
@@ -3772,8 +3710,6 @@ void
 RemoveDisableEdgesThruHierPin::visit(Pin *drvr,
 				     Pin *load)
 {
-  if (graph_)
-    annotateGraphDisabledWireEdge(drvr, load, false, graph_);
   PinPair probe(drvr, load);
   PinPair *pair = pairs_->findKey(&probe);
   if (pair) {
@@ -3790,11 +3726,8 @@ Sdc::removeDisable(Pin *pin)
     RemoveDisableEdgesThruHierPin visitor(&disabled_wire_edges_, graph_);
     visitDrvrLoadsThruHierPin(pin, network_, &visitor);
   }
-  else {
-    if (graph_)
-      annotateGraphDisabled(pin, false);
+  else
     disabled_pins_.erase(pin);
-  }
 }
 
 bool
@@ -6056,370 +5989,6 @@ Sdc::clkHpinDisablesChanged(Pin *pin)
 
 ////////////////////////////////////////////////////////////////
 
-// Annotate constraints to the timing graph.
-void
-Sdc::annotateGraph(bool annotate)
-{
-  Stats stats(debug_);
-  // All output pins are considered constrained because
-  // they may be downstream from a set_min/max_delay -from that
-  // does not have a set_output_delay.
-  annotateGraphConstrainOutputs();
-  annotateDisables(annotate);
-  annotateGraphOutputDelays(annotate);
-  annotateGraphDataChecks(annotate);
-  annotateHierClkLatency(annotate);
-  stats.report("Annotate constraints to graph");
-}
-
-void
-Sdc::annotateGraphConstrainOutputs()
-{
-  Instance *top_inst = network_->topInstance();
-  InstancePinIterator *pin_iter = network_->pinIterator(top_inst);
-  while (pin_iter->hasNext()) {
-    Pin *pin = pin_iter->next();
-    if (network_->direction(pin)->isAnyOutput())
-      annotateGraphConstrained(pin, true);
-  }
-  delete pin_iter;
-}
-
-void
-Sdc::annotateDisables(bool annotate)
-{
-  PinSet::Iterator pin_iter(disabled_pins_);
-  while (pin_iter.hasNext()) {
-    Pin *pin = pin_iter.next();
-    annotateGraphDisabled(pin, annotate);
-  }
-
-  if (!disabled_lib_ports_.empty()) {
-    VertexIterator vertex_iter(graph_);
-    while (vertex_iter.hasNext()) {
-      Vertex *vertex = vertex_iter.next();
-      Pin *pin = vertex->pin();
-      LibertyPort *port = network_->libertyPort(pin);
-      if (disabled_lib_ports_.hasKey(port))
-	annotateGraphDisabled(pin, annotate);
-    }
-  }
-
-  Instance *top_inst = network_->topInstance();
-  PortSet::Iterator port_iter(disabled_ports_);
-  while (port_iter.hasNext()) {
-    Port *port = port_iter.next();
-    Pin *pin = network_->findPin(top_inst, port);
-    annotateGraphDisabled(pin, annotate);
-  }
-
-  PinPairSet::Iterator pair_iter(disabled_wire_edges_);
-  while (pair_iter.hasNext()) {
-    PinPair *pair = pair_iter.next();
-    annotateGraphDisabledWireEdge(pair->first, pair->second, annotate, graph_);
-  }
-
-  EdgeSet::Iterator edge_iter(disabled_edges_);
-  while (edge_iter.hasNext()) {
-    Edge *edge = edge_iter.next();
-    edge->setIsDisabledConstraint(annotate);
-  }
-
-  DisabledInstancePortsMap::Iterator disable_inst_iter(disabled_inst_ports_);
-  while (disable_inst_iter.hasNext()) {
-    DisabledInstancePorts *disabled_inst = disable_inst_iter.next();
-    setEdgeDisabledInstPorts(disabled_inst, annotate);
-  }
-}
-
-class DisableHpinEdgeVisitor : public HierPinThruVisitor
-{
-public:
-  DisableHpinEdgeVisitor(bool annotate, Graph *graph);
-  virtual void visit(Pin *from_pin,
-		     Pin *to_pin);
-
-protected:
-  bool annotate_;
-  Graph *graph_;
-
-private:
-  DISALLOW_COPY_AND_ASSIGN(DisableHpinEdgeVisitor);
-};
-
-DisableHpinEdgeVisitor::DisableHpinEdgeVisitor(bool annotate,
-					       Graph *graph) :
-  HierPinThruVisitor(),
-  annotate_(annotate),
-  graph_(graph)
-{
-}
-
-void
-DisableHpinEdgeVisitor::visit(Pin *from_pin,
-			      Pin *to_pin)
-{
-  annotateGraphDisabledWireEdge(from_pin, to_pin, annotate_, graph_);
-}
-
-static void
-annotateGraphDisabledWireEdge(Pin *from_pin,
-			      Pin *to_pin,
-			      bool annotate,
-			      Graph *graph)
-{
-  Vertex *from_vertex = graph->pinDrvrVertex(from_pin);
-  Vertex *to_vertex = graph->pinLoadVertex(to_pin);
-  if (from_vertex && to_vertex) {
-    VertexOutEdgeIterator edge_iter(from_vertex, graph);
-    while (edge_iter.hasNext()) {
-      Edge *edge = edge_iter.next();
-      if (edge->isWire()
-	  && edge->to(graph) == to_vertex)
-	edge->setIsDisabledConstraint(annotate);
-    }
-  }
-}
-
-void
-Sdc::annotateGraphDisabled(const Pin *pin,
-			   bool annotate)
-{
-  Vertex *vertex, *bidirect_drvr_vertex;
-  graph_->pinVertices(pin, vertex, bidirect_drvr_vertex);
-  vertex->setIsDisabledConstraint(annotate);
-  if (bidirect_drvr_vertex)
-    bidirect_drvr_vertex->setIsDisabledConstraint(annotate);
-}
-
-void
-Sdc::setEdgeDisabledInstPorts(DisabledInstancePorts *disabled_inst,
-			      bool annotate)
-{
-  setEdgeDisabledInstPorts(disabled_inst, disabled_inst->instance(), annotate);
-}
-
-void
-Sdc::setEdgeDisabledInstPorts(DisabledPorts *disabled_port,
-			      Instance *inst,
-			      bool annotate)
-{
-  if (disabled_port->all()) {
-    InstancePinIterator *pin_iter = network_->pinIterator(inst);
-    while (pin_iter->hasNext()) {
-      Pin *pin = pin_iter->next();
-      // set_disable_timing instance does not disable timing checks.
-      setEdgeDisabledInstFrom(pin, false, annotate);
-    }
-    delete pin_iter;
-  }
-
-  // Disable from pins.
-  LibertyPortSet::Iterator from_iter(disabled_port->from());
-  while (from_iter.hasNext()) {
-    LibertyPort *from_port = from_iter.next();
-    Pin *from_pin = network_->findPin(inst, from_port);
-    if (from_pin)
-      setEdgeDisabledInstFrom(from_pin, true, annotate);
-  }
-
-  // Disable to pins.
-  LibertyPortSet::Iterator to_iter(disabled_port->to());
-  while (to_iter.hasNext()) {
-    LibertyPort *to_port = to_iter.next();
-    Pin *to_pin = network_->findPin(inst, to_port);
-    if (to_pin) {
-      if (network_->direction(to_pin)->isAnyOutput()) {
-	Vertex *vertex = graph_->pinDrvrVertex(to_pin);
-	if (vertex) {
-	  VertexInEdgeIterator edge_iter(vertex, graph_);
-	  while (edge_iter.hasNext()) {
-	    Edge *edge = edge_iter.next();
-	    edge->setIsDisabledConstraint(annotate);
-	  }
-	}
-      }
-    }
-  }
-
-  // Disable from/to pins.
-  LibertyPortPairSet::Iterator from_to_iter(disabled_port->fromTo());
-  while (from_to_iter.hasNext()) {
-    LibertyPortPair *pair = from_to_iter.next();
-    const LibertyPort *from_port = pair->first;
-    const LibertyPort *to_port = pair->second;
-    Pin *from_pin = network_->findPin(inst, from_port);
-    Pin *to_pin = network_->findPin(inst, to_port);
-    if (from_pin && network_->direction(from_pin)->isAnyInput()
-	&& to_pin) {
-      Vertex *from_vertex = graph_->pinLoadVertex(from_pin);
-      Vertex *to_vertex = graph_->pinDrvrVertex(to_pin);
-      if (from_vertex && to_vertex) {
-	VertexOutEdgeIterator edge_iter(from_vertex, graph_);
-	while (edge_iter.hasNext()) {
-	  Edge *edge = edge_iter.next();
-	  if (edge->to(graph_) == to_vertex)
-	    edge->setIsDisabledConstraint(annotate);
-	}
-      }
-    }
-  }
-}
-
-void
-Sdc::setEdgeDisabledInstFrom(Pin *from_pin,
-			     bool disable_checks,
-			     bool annotate)
-{
-  if (network_->direction(from_pin)->isAnyInput()) {
-    Vertex *from_vertex = graph_->pinLoadVertex(from_pin);
-    if (from_vertex) {
-      VertexOutEdgeIterator edge_iter(from_vertex, graph_);
-      while (edge_iter.hasNext()) {
-	Edge *edge = edge_iter.next();
-	if (disable_checks
-	    || !edge->role()->isTimingCheck())
-	  edge->setIsDisabledConstraint(annotate);
-      }
-    }
-  }
-}
-
-void
-Sdc::annotateGraphOutputDelays(bool annotate)
-{
-  for (OutputDelay *output_delay : output_delays_) {
-    for (Pin *lpin : output_delay->leafPins())
-      annotateGraphConstrained(lpin, annotate);
-  }
-}
-
-void
-Sdc::annotateGraphDataChecks(bool annotate)
-{
-  DataChecksMap::Iterator data_checks_iter(data_checks_to_map_);
-  while (data_checks_iter.hasNext()) {
-    DataCheckSet *checks = data_checks_iter.next();
-    DataCheckSet::Iterator check_iter(checks);
-    // There may be multiple data checks on a single pin,
-    // but we only need to mark it as constrained once.
-    if (check_iter.hasNext()) {
-      DataCheck *check = check_iter.next();
-      annotateGraphConstrained(check->to(), annotate);
-    }
-  }
-}
-
-void
-Sdc::annotateGraphConstrained(const PinSet *pins,
-			      bool annotate)
-{
-  PinSet::ConstIterator pin_iter(pins);
-  while (pin_iter.hasNext()) {
-    const Pin *pin = pin_iter.next();
-    annotateGraphConstrained(pin, annotate);
-  }
-}
-
-void
-Sdc::annotateGraphConstrained(const InstanceSet *insts,
-			      bool annotate)
-{
-  InstanceSet::ConstIterator inst_iter(insts);
-  while (inst_iter.hasNext()) {
-    const Instance *inst = inst_iter.next();
-    annotateGraphConstrained(inst, annotate);
-  }
-}
-
-void
-Sdc::annotateGraphConstrained(const Instance *inst,
-			      bool annotate)
-{
-  InstancePinIterator *pin_iter = network_->pinIterator(inst);
-  while (pin_iter->hasNext()) {
-    Pin *pin = pin_iter->next();
-    if (network_->direction(pin)->isAnyInput())
-      annotateGraphConstrained(pin, annotate);
-  }
-  delete pin_iter;
-}
-
-void
-Sdc::annotateGraphConstrained(const Pin *pin,
-			      bool annotate)
-{
-  Vertex *vertex, *bidirect_drvr_vertex;
-  graph_->pinVertices(pin, vertex, bidirect_drvr_vertex);
-  // Pin may be hierarchical and have no vertex.
-  if (vertex)
-    vertex->setIsConstrained(annotate);
-  if (bidirect_drvr_vertex)
-    bidirect_drvr_vertex->setIsConstrained(annotate);
-}
-
-void
-Sdc::annotateHierClkLatency(bool annotate)
-{
-  if (annotate) {
-    ClockLatencies::Iterator latency_iter(clk_latencies_);
-    while (latency_iter.hasNext()) {
-      ClockLatency *latency = latency_iter.next();
-      const Pin *pin = latency->pin();
-      if (pin && network_->isHierarchical(pin))
-	annotateHierClkLatency(pin, latency);
-    }
-  }
-  else
-    edge_clk_latency_.clear();
-}
-
-void
-Sdc::annotateHierClkLatency(const Pin *hpin,
-			    ClockLatency *latency)
-{
-  EdgesThruHierPinIterator edge_iter(hpin, network_, graph_);
-  while (edge_iter.hasNext()) {
-    Edge *edge = edge_iter.next();
-    edge_clk_latency_[edge] = latency;
-  }
-}
-
-void
-Sdc::deannotateHierClkLatency(const Pin *hpin)
-{
-  EdgesThruHierPinIterator edge_iter(hpin, network_, graph_);
-  while (edge_iter.hasNext()) {
-    Edge *edge = edge_iter.next();
-    edge_clk_latency_.erase(edge);
-  }
-}
-
-ClockLatency *
-Sdc::clockLatency(Edge *edge) const
-{
-  return edge_clk_latency_.findKey(edge);
-}
-
-void
-Sdc::clockLatency(Edge *edge,
-		  const RiseFall *rf,
-		  const MinMax *min_max,
-		  // Return values.
-		  float &latency,
-		  bool &exists) const
-{
-  ClockLatency *latencies = edge_clk_latency_.findKey(edge);
-  if (latencies)
-    latencies->delay(rf, min_max, latency, exists);
-  else {
-    latency = 0.0;
-    exists = false;
-  }
-}
-
-////////////////////////////////////////////////////////////////
-
 // Find the leaf load pins corresponding to pin.
 // If the pin is hierarchical, the leaf pins are:
 //   hierarchical  input - load pins  inside the hierarchical instance
diff --git a/sdc/SdcGraph.cc b/sdc/SdcGraph.cc
new file mode 100644
index 00000000..5fca8d79
--- /dev/null
+++ b/sdc/SdcGraph.cc
@@ -0,0 +1,397 @@
+// OpenSTA, Static Timing Analyzer
+// Copyright (c) 2020, Parallax Software, Inc.
+// 
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+// 
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+// 
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+#include "Stats.hh"
+#include "PortDirection.hh"
+#include "Network.hh"
+#include "Graph.hh"
+#include "DisabledPorts.hh"
+#include "PortDelay.hh"
+#include "ClockLatency.hh"
+#include "Sdc.hh"
+
+namespace sta {
+
+static void
+annotateGraphDisabledWireEdge(Pin *from_pin,
+			      Pin *to_pin,
+			      Graph *graph);
+
+// Annotate constraints to the timing graph.
+void
+Sdc::annotateGraph()
+{
+  Stats stats(debug_);
+  // All output pins are considered constrained because
+  // they may be downstream from a set_min/max_delay -from that
+  // does not have a set_output_delay.
+  annotateGraphConstrainOutputs();
+  annotateDisables();
+  annotateGraphOutputDelays();
+  annotateGraphDataChecks();
+  annotateHierClkLatency();
+  stats.report("Annotate constraints to graph");
+}
+
+void
+Sdc::annotateGraphConstrainOutputs()
+{
+  Instance *top_inst = network_->topInstance();
+  InstancePinIterator *pin_iter = network_->pinIterator(top_inst);
+  while (pin_iter->hasNext()) {
+    Pin *pin = pin_iter->next();
+    if (network_->direction(pin)->isAnyOutput())
+      annotateGraphConstrained(pin);
+  }
+  delete pin_iter;
+}
+
+void
+Sdc::annotateDisables()
+{
+  PinSet::Iterator pin_iter(disabled_pins_);
+  while (pin_iter.hasNext()) {
+    Pin *pin = pin_iter.next();
+    annotateGraphDisabled(pin);
+  }
+
+  if (!disabled_lib_ports_.empty()) {
+    VertexIterator vertex_iter(graph_);
+    while (vertex_iter.hasNext()) {
+      Vertex *vertex = vertex_iter.next();
+      Pin *pin = vertex->pin();
+      LibertyPort *port = network_->libertyPort(pin);
+      if (disabled_lib_ports_.hasKey(port))
+	annotateGraphDisabled(pin);
+    }
+  }
+
+  Instance *top_inst = network_->topInstance();
+  PortSet::Iterator port_iter(disabled_ports_);
+  while (port_iter.hasNext()) {
+    Port *port = port_iter.next();
+    Pin *pin = network_->findPin(top_inst, port);
+    annotateGraphDisabled(pin);
+  }
+
+  PinPairSet::Iterator pair_iter(disabled_wire_edges_);
+  while (pair_iter.hasNext()) {
+    PinPair *pair = pair_iter.next();
+    annotateGraphDisabledWireEdge(pair->first, pair->second, graph_);
+  }
+
+  EdgeSet::Iterator edge_iter(disabled_edges_);
+  while (edge_iter.hasNext()) {
+    Edge *edge = edge_iter.next();
+    edge->setIsDisabledConstraint(true);
+  }
+
+  DisabledInstancePortsMap::Iterator disable_inst_iter(disabled_inst_ports_);
+  while (disable_inst_iter.hasNext()) {
+    DisabledInstancePorts *disabled_inst = disable_inst_iter.next();
+    setEdgeDisabledInstPorts(disabled_inst);
+  }
+}
+
+class DisableHpinEdgeVisitor : public HierPinThruVisitor
+{
+public:
+  DisableHpinEdgeVisitor(Graph *graph);
+  virtual void visit(Pin *from_pin,
+		     Pin *to_pin);
+
+protected:
+  bool annotate_;
+  Graph *graph_;
+
+private:
+  DISALLOW_COPY_AND_ASSIGN(DisableHpinEdgeVisitor);
+};
+
+DisableHpinEdgeVisitor::DisableHpinEdgeVisitor(Graph *graph) :
+  HierPinThruVisitor(),
+  graph_(graph)
+{
+}
+
+void
+DisableHpinEdgeVisitor::visit(Pin *from_pin,
+			      Pin *to_pin)
+{
+  annotateGraphDisabledWireEdge(from_pin, to_pin, graph_);
+}
+
+static void
+annotateGraphDisabledWireEdge(Pin *from_pin,
+			      Pin *to_pin,
+			      Graph *graph)
+{
+  Vertex *from_vertex = graph->pinDrvrVertex(from_pin);
+  Vertex *to_vertex = graph->pinLoadVertex(to_pin);
+  if (from_vertex && to_vertex) {
+    VertexOutEdgeIterator edge_iter(from_vertex, graph);
+    while (edge_iter.hasNext()) {
+      Edge *edge = edge_iter.next();
+      if (edge->isWire()
+	  && edge->to(graph) == to_vertex)
+	edge->setIsDisabledConstraint(true);
+    }
+  }
+}
+
+void
+Sdc::annotateGraphDisabled(const Pin *pin)
+{
+  Vertex *vertex, *bidirect_drvr_vertex;
+  graph_->pinVertices(pin, vertex, bidirect_drvr_vertex);
+  vertex->setIsDisabledConstraint(true);
+  if (bidirect_drvr_vertex)
+    bidirect_drvr_vertex->setIsDisabledConstraint(true);
+}
+
+void
+Sdc::setEdgeDisabledInstPorts(DisabledInstancePorts *disabled_inst)
+{
+  setEdgeDisabledInstPorts(disabled_inst, disabled_inst->instance());
+}
+
+void
+Sdc::setEdgeDisabledInstPorts(DisabledPorts *disabled_port,
+			      Instance *inst)
+{
+  if (disabled_port->all()) {
+    InstancePinIterator *pin_iter = network_->pinIterator(inst);
+    while (pin_iter->hasNext()) {
+      Pin *pin = pin_iter->next();
+      // set_disable_timing instance does not disable timing checks.
+      setEdgeDisabledInstFrom(pin, false);
+    }
+    delete pin_iter;
+  }
+
+  // Disable from pins.
+  LibertyPortSet::Iterator from_iter(disabled_port->from());
+  while (from_iter.hasNext()) {
+    LibertyPort *from_port = from_iter.next();
+    Pin *from_pin = network_->findPin(inst, from_port);
+    if (from_pin)
+      setEdgeDisabledInstFrom(from_pin, true);
+  }
+
+  // Disable to pins.
+  LibertyPortSet::Iterator to_iter(disabled_port->to());
+  while (to_iter.hasNext()) {
+    LibertyPort *to_port = to_iter.next();
+    Pin *to_pin = network_->findPin(inst, to_port);
+    if (to_pin) {
+      if (network_->direction(to_pin)->isAnyOutput()) {
+	Vertex *vertex = graph_->pinDrvrVertex(to_pin);
+	if (vertex) {
+	  VertexInEdgeIterator edge_iter(vertex, graph_);
+	  while (edge_iter.hasNext()) {
+	    Edge *edge = edge_iter.next();
+	    edge->setIsDisabledConstraint(true);
+	  }
+	}
+      }
+    }
+  }
+
+  // Disable from/to pins.
+  LibertyPortPairSet::Iterator from_to_iter(disabled_port->fromTo());
+  while (from_to_iter.hasNext()) {
+    LibertyPortPair *pair = from_to_iter.next();
+    const LibertyPort *from_port = pair->first;
+    const LibertyPort *to_port = pair->second;
+    Pin *from_pin = network_->findPin(inst, from_port);
+    Pin *to_pin = network_->findPin(inst, to_port);
+    if (from_pin && network_->direction(from_pin)->isAnyInput()
+	&& to_pin) {
+      Vertex *from_vertex = graph_->pinLoadVertex(from_pin);
+      Vertex *to_vertex = graph_->pinDrvrVertex(to_pin);
+      if (from_vertex && to_vertex) {
+	VertexOutEdgeIterator edge_iter(from_vertex, graph_);
+	while (edge_iter.hasNext()) {
+	  Edge *edge = edge_iter.next();
+	  if (edge->to(graph_) == to_vertex)
+	    edge->setIsDisabledConstraint(true);
+	}
+      }
+    }
+  }
+}
+
+void
+Sdc::setEdgeDisabledInstFrom(Pin *from_pin,
+			     bool disable_checks)
+{
+  if (network_->direction(from_pin)->isAnyInput()) {
+    Vertex *from_vertex = graph_->pinLoadVertex(from_pin);
+    if (from_vertex) {
+      VertexOutEdgeIterator edge_iter(from_vertex, graph_);
+      while (edge_iter.hasNext()) {
+	Edge *edge = edge_iter.next();
+	if (disable_checks
+	    || !edge->role()->isTimingCheck())
+	  edge->setIsDisabledConstraint(true);
+      }
+    }
+  }
+}
+
+void
+Sdc::annotateGraphOutputDelays()
+{
+  for (OutputDelay *output_delay : output_delays_) {
+    for (Pin *lpin : output_delay->leafPins())
+      annotateGraphConstrained(lpin);
+  }
+}
+
+void
+Sdc::annotateGraphDataChecks()
+{
+  DataChecksMap::Iterator data_checks_iter(data_checks_to_map_);
+  while (data_checks_iter.hasNext()) {
+    DataCheckSet *checks = data_checks_iter.next();
+    DataCheckSet::Iterator check_iter(checks);
+    // There may be multiple data checks on a single pin,
+    // but we only need to mark it as constrained once.
+    if (check_iter.hasNext()) {
+      DataCheck *check = check_iter.next();
+      annotateGraphConstrained(check->to());
+    }
+  }
+}
+
+void
+Sdc::annotateGraphConstrained(const PinSet *pins)
+{
+  PinSet::ConstIterator pin_iter(pins);
+  while (pin_iter.hasNext()) {
+    const Pin *pin = pin_iter.next();
+    annotateGraphConstrained(pin);
+  }
+}
+
+void
+Sdc::annotateGraphConstrained(const InstanceSet *insts)
+{
+  InstanceSet::ConstIterator inst_iter(insts);
+  while (inst_iter.hasNext()) {
+    const Instance *inst = inst_iter.next();
+    annotateGraphConstrained(inst);
+  }
+}
+
+void
+Sdc::annotateGraphConstrained(const Instance *inst)
+{
+  InstancePinIterator *pin_iter = network_->pinIterator(inst);
+  while (pin_iter->hasNext()) {
+    Pin *pin = pin_iter->next();
+    if (network_->direction(pin)->isAnyInput())
+      annotateGraphConstrained(pin);
+  }
+  delete pin_iter;
+}
+
+void
+Sdc::annotateGraphConstrained(const Pin *pin)
+{
+  Vertex *vertex, *bidirect_drvr_vertex;
+  graph_->pinVertices(pin, vertex, bidirect_drvr_vertex);
+  // Pin may be hierarchical and have no vertex.
+  if (vertex)
+    vertex->setIsConstrained(true);
+  if (bidirect_drvr_vertex)
+    bidirect_drvr_vertex->setIsConstrained(true);
+}
+
+void
+Sdc::annotateHierClkLatency()
+{
+  ClockLatencies::Iterator latency_iter(clk_latencies_);
+  while (latency_iter.hasNext()) {
+    ClockLatency *latency = latency_iter.next();
+    const Pin *pin = latency->pin();
+    if (pin && network_->isHierarchical(pin))
+      annotateHierClkLatency(pin, latency);
+  }
+}
+
+void
+Sdc::annotateHierClkLatency(const Pin *hpin,
+			    ClockLatency *latency)
+{
+  EdgesThruHierPinIterator edge_iter(hpin, network_, graph_);
+  while (edge_iter.hasNext()) {
+    Edge *edge = edge_iter.next();
+    edge_clk_latency_[edge] = latency;
+  }
+}
+
+ClockLatency *
+Sdc::clockLatency(Edge *edge) const
+{
+  return edge_clk_latency_.findKey(edge);
+}
+
+void
+Sdc::clockLatency(Edge *edge,
+		  const RiseFall *rf,
+		  const MinMax *min_max,
+		  // Return values.
+		  float &latency,
+		  bool &exists) const
+{
+  ClockLatency *latencies = edge_clk_latency_.findKey(edge);
+  if (latencies)
+    latencies->delay(rf, min_max, latency, exists);
+  else {
+    latency = 0.0;
+    exists = false;
+  }
+}
+
+////////////////////////////////////////////////////////////////
+
+void
+Sdc::removeGraphAnnotations()
+{
+  VertexIterator vertex_iter(graph_);
+  while (vertex_iter.hasNext()) {
+    Vertex *vertex = vertex_iter.next();
+    vertex->setIsDisabledConstraint(false);
+    vertex->setIsConstrained(false);
+
+    VertexOutEdgeIterator edge_iter(vertex, graph_);
+    while (edge_iter.hasNext()) {
+      Edge *edge = edge_iter.next();
+      edge->setIsDisabledConstraint(false);
+    }
+  }
+  edge_clk_latency_.clear();
+}
+
+void
+Sdc::searchPreamble()
+{
+  ensureClkHpinDisables();
+  ensureClkGroupExclusions();
+}
+
+} // namespace
diff --git a/sdc/WriteSdc.cc b/sdc/WriteSdc.cc
index 71515f65..15b27e19 100644
--- a/sdc/WriteSdc.cc
+++ b/sdc/WriteSdc.cc
@@ -1578,7 +1578,8 @@ WriteSdc::writeEnvironment() const
   writeCommentSection("Environment");
   writeOperatingConditions();
   writeWireload();
-  writePinLoads();
+  writePortLoads();
+  writeNetLoads();
   writeDriveResistances();
   writeDrivingCells();
   writeInputTransitions();
@@ -1606,7 +1607,44 @@ WriteSdc::writeWireload() const
 }
 
 void
-WriteSdc::writePinLoads() const
+WriteSdc::writeNetLoads() const
+{
+  if (sdc_->net_wire_cap_map_) {
+    for (auto net_cap : *sdc_->net_wire_cap_map_) {
+      Net *net = net_cap.first;
+      MinMaxFloatValues &caps = net_cap.second;
+      float min_cap, max_cap;
+      bool min_exists, max_exists;
+      caps.value(MinMax::min(), min_cap, min_exists);
+      caps.value(MinMax::max(), max_cap, max_exists);
+      if (min_exists && max_exists
+	  && min_cap == max_cap)
+	writeNetLoad(net, MinMaxAll::all(), min_cap);
+      else {
+	if (min_exists)
+	  writeNetLoad(net, MinMaxAll::min(), min_cap);
+	if (max_exists)
+	  writeNetLoad(net, MinMaxAll::max(), max_cap);
+      }
+    }
+  }
+}
+
+void
+WriteSdc::writeNetLoad(Net *net,
+		       const MinMaxAll *min_max,
+		       float cap) const
+{
+  fprintf(stream_, "set_load ");
+  fprintf(stream_, "%s ", minMaxFlag(min_max));
+  writeCapacitance(cap);
+  fprintf(stream_, " ");
+  writeGetNet(net);
+  fprintf(stream_, "\n");
+}
+
+void
+WriteSdc::writePortLoads() const
 {
   CellPortBitIterator *port_iter = sdc_network_->portBitIterator(cell_);
   while (port_iter->hasNext()) {
diff --git a/sdc/WriteSdcPvt.hh b/sdc/WriteSdcPvt.hh
index 83ee4d2e..4cc69ddd 100644
--- a/sdc/WriteSdcPvt.hh
+++ b/sdc/WriteSdcPvt.hh
@@ -117,7 +117,11 @@ public:
   void writeEnvironment() const;
   void writeOperatingConditions() const;
   void writeWireload() const;
-  void writePinLoads() const;
+  void writeNetLoads() const;
+  void writeNetLoad(Net *net,
+		    const MinMaxAll *min_max,
+		    float cap) const;
+  void writePortLoads() const;
   void writePortLoads(Port *port) const;
   void writePortFanout(Port *port) const;
   void writeDriveResistances() const;
diff --git a/sdf/SdfReader.cc b/sdf/SdfReader.cc
index 98f7dff6..e0f91d77 100644
--- a/sdf/SdfReader.cc
+++ b/sdf/SdfReader.cc
@@ -809,7 +809,7 @@ SdfReader::setEdgeArcDelaysCondUse(Edge *edge,
       delay = graph_->arcDelay(edge, arc, arc_delay_index) + *value;
     else if (graph_->arcDelayAnnotated(edge, arc, arc_delay_index)) {
       ArcDelay prev_value = graph_->arcDelay(edge, arc, arc_delay_index);
-      if (fuzzyGreater(prev_value, delay, min_max))
+      if (delayGreater(prev_value, delay, min_max, this))
 	delay = prev_value;
     }
     graph_->setArcDelay(edge, arc, arc_delay_index, delay);
diff --git a/sdf/SdfWriter.cc b/sdf/SdfWriter.cc
index 4287776c..09b408ad 100644
--- a/sdf/SdfWriter.cc
+++ b/sdf/SdfWriter.cc
@@ -605,18 +605,18 @@ SdfWriter::writeEdgeCheck(Edge *edge,
       && arcs[clk_rf_index][RiseFall::fallIndex()]
       && arcs[clk_rf_index][RiseFall::riseIndex()]
       && arcs[clk_rf_index][RiseFall::fallIndex()]
-      && fuzzyEqual(graph_->arcDelay(edge, 
-				       arcs[clk_rf_index][RiseFall::riseIndex()],
-				       arc_delay_min_index_),
-			 graph_->arcDelay(edge,
-					  arcs[clk_rf_index][RiseFall::fallIndex()],
-					  arc_delay_min_index_))
-      && fuzzyEqual(graph_->arcDelay(edge,
-					  arcs[clk_rf_index][RiseFall::riseIndex()],
-					  arc_delay_max_index_),
-			 graph_->arcDelay(edge,
-					  arcs[clk_rf_index][RiseFall::fallIndex()],
-					  arc_delay_max_index_)))
+      && delayEqual(graph_->arcDelay(edge, 
+				     arcs[clk_rf_index][RiseFall::riseIndex()],
+				     arc_delay_min_index_),
+		    graph_->arcDelay(edge,
+				     arcs[clk_rf_index][RiseFall::fallIndex()],
+				     arc_delay_min_index_))
+      && delayEqual(graph_->arcDelay(edge,
+				     arcs[clk_rf_index][RiseFall::riseIndex()],
+				     arc_delay_max_index_),
+		    graph_->arcDelay(edge,
+				     arcs[clk_rf_index][RiseFall::fallIndex()],
+				     arc_delay_max_index_)))
     // Rise/fall margins are the same, so no data edge specifier is required.
     writeCheck(edge, arcs[clk_rf_index][RiseFall::riseIndex()],
 	       sdf_check, false, true);
diff --git a/search/CheckFanoutLimits.cc b/search/CheckFanoutLimits.cc
index cda77d9c..b5c2ae42 100644
--- a/search/CheckFanoutLimits.cc
+++ b/search/CheckFanoutLimits.cc
@@ -182,15 +182,19 @@ CheckFanoutLimits::fanoutLoad(const Pin *pin) const
       Pin *pin = pin_iter->next();
       if (network->isLoad(pin)) {
 	LibertyPort *port = network->libertyPort(pin);
-	float fanout_load;
-	bool exists;
-	port->fanoutLoad(fanout_load, exists);
-	if (!exists) {
-	  LibertyLibrary *lib = port->libertyLibrary();
-	  lib->defaultFanoutLoad(fanout_load, exists);
+	if (port) {
+	  float fanout_load;
+	  bool exists;
+	  port->fanoutLoad(fanout_load, exists);
+	  if (!exists) {
+	    LibertyLibrary *lib = port->libertyLibrary();
+	    lib->defaultFanoutLoad(fanout_load, exists);
+	  }
+	  if (exists)
+	    fanout += fanout_load;
 	}
-	if (exists)
-	  fanout += fanout_load;
+	else
+	  fanout += 1;
       }
     }
     delete pin_iter;
diff --git a/search/CheckMaxSkews.cc b/search/CheckMaxSkews.cc
index d7020cc5..19583141 100644
--- a/search/CheckMaxSkews.cc
+++ b/search/CheckMaxSkews.cc
@@ -107,7 +107,7 @@ void
 MaxSkewViolatorsVisititor::visit(MaxSkewCheck &check,
 				 const StaState *sta)
 {
-  if (fuzzyLess(check.slack(sta), 0.0))
+  if (delayLess(check.slack(sta), 0.0, sta))
     checks_.push_back(new MaxSkewCheck(check));
 }
 
@@ -280,8 +280,8 @@ MaxSkewSlackLess::operator()(const MaxSkewCheck *check1,
 {
   Slack slack1 = check1->slack(sta_);
   Slack slack2 = check2->slack(sta_);
-  return slack1 < slack2
-    || (fuzzyEqual(slack1, slack2)
+  return delayLess(slack1, slack2, sta_)
+    || (delayEqual(slack1, slack2)
 	// Break ties based on constrained pin names.
 	&& sta_->network()->pinLess(check1->clkPin(sta_),check2->clkPin(sta_)));
 }
diff --git a/search/CheckMinPeriods.cc b/search/CheckMinPeriods.cc
index dd21636d..e4a47c70 100644
--- a/search/CheckMinPeriods.cc
+++ b/search/CheckMinPeriods.cc
@@ -79,7 +79,7 @@ void
 MinPeriodViolatorsVisitor::visit(MinPeriodCheck &check,
 				 StaState *sta)
 {
-  if (fuzzyLess(check.slack(sta), 0.0))
+  if (delayLess(check.slack(sta), 0.0, sta))
     checks_.push_back(check.copy());
 }
 
@@ -231,9 +231,9 @@ MinPeriodSlackLess::operator()(const MinPeriodCheck *check1,
   Slack slack2 = check2->slack(sta_);
   const Pin *pin1 = check1->pin();
   const Pin *pin2 = check2->pin();
-  return fuzzyLess(slack1, slack2)
+  return delayLess(slack1, slack2, sta_)
     // Break ties based on pin and clock names.
-    || (fuzzyEqual(slack1, slack2)
+    || (delayEqual(slack1, slack2)
 	&& (sta_->network()->pinLess(pin1, pin2)
 	    || (pin1 == pin2
 		&& ClockNameLess()(check1->clk(),
diff --git a/search/CheckMinPulseWidths.cc b/search/CheckMinPulseWidths.cc
index 385662c0..28fe6dec 100644
--- a/search/CheckMinPulseWidths.cc
+++ b/search/CheckMinPulseWidths.cc
@@ -167,7 +167,7 @@ void
 MinPulseWidthViolatorsVisitor::visit(MinPulseWidthCheck &check,
 				     const StaState *sta)
 {
-  if (fuzzyLess(check.slack(sta), 0.0)
+  if (delayLess(check.slack(sta), 0.0, sta)
       && (corner_ == nullptr
 	  || check.corner(sta) == corner_)) {
     MinPulseWidthCheck *copy = new MinPulseWidthCheck(check.openPath());
@@ -499,8 +499,8 @@ MinPulseWidthSlackLess::operator()(const MinPulseWidthCheck *check1,
   Slack slack2 = check2->slack(sta_);
   const Pin *pin1 = check1->pin(sta_);
   const Pin *pin2 = check2->pin(sta_);
-  return slack1 < slack2
-    || (fuzzyEqual(slack1, slack2)
+  return delayLess(slack1, slack2, sta_)
+    || (delayEqual(slack1, slack2)
 	// Break ties for the sake of regression stability.
 	&& (sta_->network()->pinLess(pin1, pin2)
 	    || (pin1 == pin2
diff --git a/search/ClkInfo.cc b/search/ClkInfo.cc
index 8638eda3..f8b0c5e0 100644
--- a/search/ClkInfo.cc
+++ b/search/ClkInfo.cc
@@ -294,9 +294,9 @@ clkInfoCmp(const ClkInfo *clk_info1,
 
   const Arrival &insert1 = clk_info1->insertion();
   const Arrival &insert2 = clk_info2->insertion();
-  if (insert1 < insert2)
+  if (delayLess(insert1, insert2, sta))
     return -1;
-  if (insert1 > insert2)
+  if (delayGreater(insert1, insert2, sta))
     return 1;
 
   float latency1 = clk_info1->latency();
diff --git a/search/Crpr.cc b/search/Crpr.cc
index 31d032cf..64496ffb 100644
--- a/search/Crpr.cc
+++ b/search/Crpr.cc
@@ -165,6 +165,8 @@ CheckCrpr::checkCrpr1(const Path *src_path,
   const MinMax *src_clk_min_max =
     src_clk_path ? src_clk_path->minMax(this) : src_path->minMax(this);
   if (crprPossible(src_clk, tgt_clk)
+      && src_clk_info->isPropagated()
+      && tgt_clk_info->isPropagated()
       // Note that crpr clk min/max is NOT the same as the path min max.
       // For path from latches that are borrowing the enable path
       // is from the opposite min/max of the data.
@@ -372,9 +374,12 @@ CheckCrpr::outputDelayCrpr1(const Path *src_path,
 {
   crpr = 0.0;
   crpr_pin = nullptr;
+  ClkInfo *src_clk_info = src_path->tag(this)->clkInfo();
   Clock *tgt_clk = tgt_clk_edge->clock();
   Clock *src_clk = src_path->clock(this);
-  if (tgt_clk->isGenerated()
+  if (src_clk_info->isPropagated()
+      && tgt_clk->isGenerated()
+      && tgt_clk->isPropagated()
       && crprPossible(src_clk, tgt_clk)) {
     PathVertex tgt_genclk_path;
     portClkPath(tgt_clk_edge, tgt_clk_edge->clock()->defaultPin(), tgt_path_ap,
@@ -393,7 +398,7 @@ CheckCrpr::crprPossible(Clock *clk1,
   return clk1 && clk2
     && !clk1->isVirtual()
     && !clk2->isVirtual()
-    // Generated clock can have crpr in the source path.
+    // Generated clocks can have crpr in the source path.
     && (clk1 == clk2
 	|| clk1->isGenerated()
 	|| clk2->isGenerated()
diff --git a/search/Genclks.cc b/search/Genclks.cc
index 78da5608..9e89fd98 100644
--- a/search/Genclks.cc
+++ b/search/Genclks.cc
@@ -968,9 +968,10 @@ Genclks::recordSrcPaths(Clock *gclk)
 	    && (!has_edges
 		|| src_clk_rf == gclk->masterClkEdgeTr(rf))
 	    && (src_path.isNull()
-		|| fuzzyGreater(path->arrival(this),
-				     src_path.arrival(this),
-				     early_late))) {
+		|| delayGreater(path->arrival(this),
+				src_path.arrival(this),
+				early_late,
+				this))) {
 	  debugPrint4(debug_, "genclk", 2, "  %s insertion %s %s %s\n",
 		      network_->pathName(gclk_pin),
 		      early_late->asString(),
diff --git a/search/Latches.cc b/search/Latches.cc
index d47b16a1..629ce6fe 100644
--- a/search/Latches.cc
+++ b/search/Latches.cc
@@ -92,13 +92,13 @@ Latches::latchRequired(const Path *data_path,
       + open_latency
       + open_uncertainty
       + PathEnd::checkSetupMcpAdjustment(data_clk_edge, enable_clk_edge, mcp,
-					 sdc_)
+					 1, sdc_)
       + open_crpr;
     debugPrint3(debug_, "latch", 1, "latch data %s %s enable %s\n",
 		network_->pathName(data_path->pin(this)),
 		delayAsString(data_arrival, this),
 		delayAsString(enable_arrival, this));
-    if (data_arrival <= enable_arrival) {
+    if (delayLessEqual(data_arrival, enable_arrival, this)) {
       // Data arrives before latch opens.
       required = enable_arrival;
       borrow = 0.0;
@@ -108,7 +108,7 @@ Latches::latchRequired(const Path *data_path,
     else {
       // Data arrives while latch is transparent.
       borrow = data_arrival - enable_arrival;
-      if (borrow <= max_borrow)
+      if (delayLessEqual(borrow, max_borrow, this))
 	required = data_arrival;
       else {
 	borrow = max_borrow;
@@ -332,7 +332,7 @@ Latches::latchOutArrival(Path *data_path,
 	   latchRequired(data_path, enable_path, &disable_path, path_ap,
 			 required, borrow, adjusted_data_arrival,
 			 time_given_to_startpoint);
-	   if (borrow > 0.0) {
+	   if (delayGreater(borrow, 0.0, this)) {
 	     // Latch is transparent when data arrives.
 	     arc_delay = search_->deratedDelay(data_vertex, d_q_arc, d_q_edge,
 					       false, path_ap);
diff --git a/search/PathEnd.cc b/search/PathEnd.cc
index 57a014c1..8e1ab6be 100644
--- a/search/PathEnd.cc
+++ b/search/PathEnd.cc
@@ -358,7 +358,9 @@ PathEnd::checkTgtClkDelay(const PathVertex *tgt_clk_path,
     const RiseFall *tgt_clk_rf = tgt_clk_edge->transition();
     insertion = search->clockInsertion(tgt_clk, tgt_src_pin, tgt_clk_rf,
 				       min_max, early_late, tgt_path_ap);
-    if (clk_info->isPropagated()) {
+    if (clk_info->isPropagated()
+	// Data check target clock is always propagated.
+	|| check_role->isDataCheck()) {
       // Propagated clock.  Propagated arrival is seeded with
       // early_late==path_min_max insertion delay.
       Arrival clk_arrival = tgt_clk_path->arrival(sta);
@@ -824,7 +826,7 @@ PathEndClkConstrainedMcp::checkMcpAdjustment(const Path *path,
     Sdc *sdc = sta->sdc();
     if (min_max == MinMax::max())
       return PathEnd::checkSetupMcpAdjustment(src_clk_edge, tgt_clk_edge,
-					      mcp_, sdc);
+					      mcp_, setupDefaultCycles(), sdc);
     else {
       // Hold check.
       // Default arrival clock is a proxy for the target clock.
@@ -874,6 +876,7 @@ float
 PathEnd::checkSetupMcpAdjustment(const ClockEdge *src_clk_edge,
 				 const ClockEdge *tgt_clk_edge,
 				 const MultiCyclePath *mcp,
+				 int default_cycles,
 				 Sdc *sdc)
 {
   if (mcp) {
@@ -887,7 +890,7 @@ PathEnd::checkSetupMcpAdjustment(const ClockEdge *src_clk_edge,
       const ClockEdge *clk_edge =
 	mcp->useEndClk() ? tgt_clk_edge : src_clk_edge;
       float period = clk_edge->clock()->period();
-      return (mult - 1) * period;
+      return (mult - default_cycles) * period;
     }
     else
       return 0.0;
@@ -1244,7 +1247,7 @@ PathEndLatchCheck::targetClkWidth(const StaState *sta) const
   if (enable_clk_info->isPulseClk())
     return disable_arrival - enable_arrival;
   else {
-    if (enable_arrival > disable_arrival) {
+    if (delayGreater(enable_arrival, disable_arrival, sta)) {
       float period = enable_clk_info->clock()->period();
       disable_arrival += period;
     }
@@ -1845,6 +1848,17 @@ PathEnd::pathDelaySrcClkOffset(const PathRef &path,
   return offset;
 }
 
+ClockEdge *
+PathEndPathDelay::targetClkEdge(const StaState *sta) const
+{
+  if (!clk_path_.isNull())
+    return clk_path_.clkEdge(sta);
+  else if (output_delay_)
+    return output_delay_->clkEdge();
+  else
+    return nullptr;
+}
+
 float 
 PathEndPathDelay::targetClkTime(const StaState *sta) const
 {
@@ -1858,14 +1872,12 @@ PathEndPathDelay::targetClkTime(const StaState *sta) const
 Arrival
 PathEndPathDelay::targetClkArrivalNoCrpr(const StaState *sta) const
 {
-  if (!clk_path_.isNull()) {
-    ClockEdge *tgt_clk_edge = targetClkEdge(sta);
-    if (tgt_clk_edge)
-      return targetClkDelay(sta)
-	+ targetClkUncertainty(sta);
-    else
-      return clk_path_.arrival(sta);
-  }
+  ClockEdge *tgt_clk_edge = targetClkEdge(sta);
+  if (tgt_clk_edge)
+    return targetClkDelay(sta)
+      + targetClkUncertainty(sta);
+  else if (!clk_path_.isNull())
+    return clk_path_.arrival(sta);
   else
     return 0.0;
 }
@@ -1887,9 +1899,7 @@ PathEndPathDelay::requiredTime(const StaState *sta) const
       return src_clk_arrival_ + delay + margin(sta);
   }
   else {
-    Arrival tgt_clk_arrival = 0.0;
-    if (!clk_path_.isNull())
-      tgt_clk_arrival = targetClkArrival(sta);
+    Arrival tgt_clk_arrival = targetClkArrival(sta);
     float src_clk_offset = sourceClkOffset(sta);
     // Path delay includes target clk latency and timing check setup/hold 
     // margin or external departure at target.
@@ -1982,24 +1992,24 @@ PathEnd::cmpSlack(const PathEnd *path_end1,
 {
   Slack slack1 = path_end1->slack(sta);
   Slack slack2 = path_end2->slack(sta);
-  if (fuzzyZero(slack1)
-      && fuzzyZero(slack2)
+  if (delayZero(slack1)
+      && delayZero(slack2)
       && path_end1->isLatchCheck()
       && path_end2->isLatchCheck()) {
     Arrival borrow1 = path_end1->borrow(sta);
     Arrival borrow2 = path_end2->borrow(sta);
     // Latch slack is zero if there is borrowing so break ties
     // based on borrow time.
-    if (fuzzyEqual(borrow1, borrow2))
+    if (delayEqual(borrow1, borrow2))
       return 0;
-    else if (borrow1 > borrow2)
+    else if (delayGreater(borrow1, borrow2, sta))
       return -1;
     else
       return 1;
   }
-  else if (fuzzyEqual(slack1, slack2))
+  else if (delayEqual(slack1, slack2))
     return 0;
-  else if (slack1 < slack2)
+  else if (delayLess(slack1, slack2, sta))
     return -1;
   else
     return 1;
@@ -2013,9 +2023,9 @@ PathEnd::cmpArrival(const PathEnd *path_end1,
   Arrival arrival1 = path_end1->dataArrivalTime(sta);
   Arrival arrival2 = path_end2->dataArrivalTime(sta);
   const MinMax *min_max = path_end1->minMax(sta);
-  if (fuzzyEqual(arrival1, arrival2))
+  if (delayEqual(arrival1, arrival2))
     return 0;
-  else if (fuzzyLess(arrival1, arrival2, min_max))
+  else if (delayLess(arrival1, arrival2, min_max, sta))
     return -1;
   else
     return 1;
diff --git a/search/PathEnum.cc b/search/PathEnum.cc
index 0d650fa1..7ff1f781 100644
--- a/search/PathEnum.cc
+++ b/search/PathEnum.cc
@@ -348,7 +348,7 @@ PathEnumFaninVisitor::visitFromToPath(const Pin *,
       // Make the diverted path end to check slack with from_path crpr.
       makeDivertedPathEnd(from_path, arc, div_end, after_div_copy);
       // Only enumerate paths with greater slack.
-      if (fuzzyGreaterEqual(div_end->slack(sta_), path_end_slack_)) {
+      if (delayGreaterEqual(div_end->slack(sta_), path_end_slack_, sta_)) {
 	reportDiversion(arc, from_path);
 	path_enum_->makeDiversion(div_end, after_div_copy);
       }
@@ -356,7 +356,7 @@ PathEnumFaninVisitor::visitFromToPath(const Pin *,
 	delete div_end;
     }
     // Only enumerate slower/faster paths.
-    else if (fuzzyLessEqual(to_arrival, before_div_arrival_, min_max)) {
+    else if (delayLessEqual(to_arrival, before_div_arrival_, min_max, sta_)) {
       PathEnd *div_end;
       PathEnumed *after_div_copy;
       makeDivertedPathEnd(from_path, arc, div_end, after_div_copy);
diff --git a/search/PathGroup.cc b/search/PathGroup.cc
index 20422f8d..0afe3ab2 100644
--- a/search/PathGroup.cc
+++ b/search/PathGroup.cc
@@ -101,19 +101,19 @@ PathGroup::savable(PathEnd *path_end)
     // without crpr first because it is expensive to find.
     Slack slack = path_end->slackNoCrpr(sta_);
     if (!delayIsInitValue(slack, min_max_)
- 	&& fuzzyLessEqual(slack, threshold_)
- 	&& fuzzyLessEqual(slack, slack_max_)) {
+ 	&& delayLessEqual(slack, threshold_, sta_)
+ 	&& delayLessEqual(slack, slack_max_, sta_)) {
       // Now check with crpr.
       slack = path_end->slack(sta_);
-      savable = fuzzyLessEqual(slack, threshold_)
- 	&& fuzzyLessEqual(slack, slack_max_)
- 	&& fuzzyGreaterEqual(slack, slack_min_);
+      savable = delayLessEqual(slack, threshold_, sta_)
+ 	&& delayLessEqual(slack, slack_max_, sta_)
+ 	&& delayGreaterEqual(slack, slack_min_, sta_);
     }
   }
   else {
     const Arrival &arrival = path_end->dataArrivalTime(sta_);
     savable = !delayIsInitValue(arrival, min_max_)
-      && fuzzyGreaterEqual(arrival, threshold_, min_max_);
+      && delayGreaterEqual(arrival, threshold_, min_max_, sta_);
   }
   return savable;
 }
diff --git a/search/PathVertex.cc b/search/PathVertex.cc
index e870f659..d26b32ab 100644
--- a/search/PathVertex.cc
+++ b/search/PathVertex.cc
@@ -403,7 +403,7 @@ PrevPathVisitor::visitFromToPath(const Pin *,
       && path_ap_index == path_ap_index_
       && (dcalc_tol_ > 0.0 
 	  ? std::abs(delayAsFloat(to_arrival - path_arrival_)) < dcalc_tol_
-	  : fuzzyEqual(to_arrival, path_arrival_))
+	  : delayEqual(to_arrival, path_arrival_))
       && (tagMatch(to_tag, path_tag_, sta_)
 	  // If the filter exception became active searching from
 	  // from_path to to_path the tag includes the filter, but
diff --git a/search/Power.cc b/search/Power.cc
index ba5ecdd5..3e274280 100644
--- a/search/Power.cc
+++ b/search/Power.cc
@@ -20,6 +20,7 @@
 
 #include "Debug.hh"
 #include "EnumNameMap.hh"
+#include "Hash.hh"
 #include "MinMax.hh"
 #include "Units.hh"
 #include "Transition.hh"
@@ -64,7 +65,7 @@ isPositiveUnate(const LibertyCell *cell,
 		const LibertyPort *from,
 		const LibertyPort *to);
 
-Power::Power(Sta *sta) :
+Power::Power(StaState *sta) :
   StaState(sta),
   global_activity_{0.0, 0.0, PwrActivityOrigin::unknown},
   input_activity_{0.1, 0.5, PwrActivityOrigin::input},
@@ -96,41 +97,93 @@ Power::setInputPortActivity(const Port *input_port,
   Instance *top_inst = network_->topInstance();
   const Pin *pin = network_->findPin(top_inst, input_port);
   if (pin) {
-    activity_map_[pin] = {activity, duty, PwrActivityOrigin::user};
+    user_activity_map_[pin] = {activity, duty, PwrActivityOrigin::user};
     activities_valid_ = false;
   }
 }
 
+void
+Power::setUserActivity(const Pin *pin,
+		      float activity,
+		      float duty,
+		      PwrActivityOrigin origin)
+{
+  user_activity_map_[pin] = {activity, duty, origin};
+  activities_valid_ = false;
+}
+
 PwrActivity &
-Power::pinActivity(const Pin *pin)
+Power::userActivity(const Pin *pin)
+{
+  return user_activity_map_[pin];
+}
+
+bool
+Power::hasUserActivity(const Pin *pin)
+{
+  return user_activity_map_.hasKey(pin);
+}
+
+void
+Power::setActivity(const Pin *pin,
+		   PwrActivity &activity)
+{
+  activity_map_[pin] = activity;
+}
+
+PwrActivity &
+Power::activity(const Pin *pin)
 {
   return activity_map_[pin];
 }
 
 bool
-Power::hasPinActivity(const Pin *pin)
+Power::hasActivity(const Pin *pin)
 {
   return activity_map_.hasKey(pin);
 }
 
+// Sequential internal pins may not be in the netlist so their
+// activities are stored by instance/liberty_port pairs.
 void
-Power::setPinActivity(const Pin *pin,
+Power::setSeqActivity(const Instance *reg,
+		      LibertyPort *output,
 		      PwrActivity &activity)
 {
-  activity_map_[pin] = activity;
+  seq_activity_map_[SeqPin(reg, output)] = activity;
   activities_valid_ = false;
 }
 
-void
-Power::setPinActivity(const Pin *pin,
-		      float activity,
-		      float duty,
-		      PwrActivityOrigin origin)
+bool
+Power::hasSeqActivity(const Instance *reg,
+		      LibertyPort *output)
 {
-  activity_map_[pin] = {activity, duty, origin};
-  activities_valid_ = false;
+  return seq_activity_map_.hasKey(SeqPin(reg, output));
 }
 
+PwrActivity
+Power::seqActivity(const Instance *reg,
+		   LibertyPort *output)
+{
+  return seq_activity_map_[SeqPin(reg, output)];
+}
+
+size_t
+SeqPinHash::operator()(const SeqPin &pin) const
+{
+  return hashSum(hashPtr(pin.first), hashPtr(pin.second));
+}
+
+bool
+SeqPinEqual::operator()(const SeqPin &pin1,
+			const SeqPin &pin2) const
+{
+  return pin1.first == pin2.first
+    && pin1.second == pin2.second;
+}
+
+////////////////////////////////////////////////////////////////
+
 void
 Power::power(const Corner *corner,
 	     // Return values.
@@ -153,7 +206,7 @@ Power::power(const Corner *corner,
     LibertyCell *cell = network_->libertyCell(inst);
     if (cell) {
       PowerResult inst_power;
-      power(inst, corner, inst_power);
+      power(inst, cell, corner, inst_power);
       if (cell->isMacro()
 	  || cell->isMemory())
 	macro.incr(inst_power);
@@ -290,44 +343,48 @@ PropActivityVisitor::visit(Vertex *vertex)
   auto pin = vertex->pin();
   debugPrint1(debug_, "power_activity", 3, "visit %s\n",
 	      vertex->name(network_));
-  bool input_without_activity = false;
-  if (network_->isLoad(pin)) {
-    VertexInEdgeIterator edge_iter(vertex, graph_);
-    if (edge_iter.hasNext()) {
-      Edge *edge = edge_iter.next();
-      if (edge->isWire()) {
-	Vertex *from_vertex = edge->from(graph_);
-	const Pin *from_pin = from_vertex->pin();
-	PwrActivity &from_activity = power_->pinActivity(from_pin);
-	PwrActivity to_activity(from_activity.activity(),
-				from_activity.duty(),
-				PwrActivityOrigin::propagated);
-	if (!power_->hasPinActivity(pin))
-	  input_without_activity = true;
-	power_->setPinActivity(pin, to_activity);
+  if (power_->hasUserActivity(pin))
+    power_->setActivity(pin, power_->userActivity(pin));
+  else {
+    bool input_without_activity = false;
+    if (network_->isLoad(pin)) {
+      VertexInEdgeIterator edge_iter(vertex, graph_);
+      if (edge_iter.hasNext()) {
+	Edge *edge = edge_iter.next();
+	if (edge->isWire()) {
+	  Vertex *from_vertex = edge->from(graph_);
+	  const Pin *from_pin = from_vertex->pin();
+	  PwrActivity &from_activity = power_->activity(from_pin);
+	  PwrActivity to_activity(from_activity.activity(),
+				  from_activity.duty(),
+				  PwrActivityOrigin::propagated);
+	  if (!power_->hasActivity(pin))
+	    input_without_activity = true;
+	  power_->setActivity(pin, to_activity);
+	}
+      }
+      Instance *inst = network_->instance(pin);
+      auto cell = network_->libertyCell(inst);
+      if (cell && cell->hasSequentials()) {
+	debugPrint1(debug_, "power_activity", 3, "pending reg %s\n",
+		    network_->pathName(inst));
+	visited_regs_->insert(inst);
+	found_reg_without_activity_ = input_without_activity;
       }
     }
-    Instance *inst = network_->instance(pin);
-    auto cell = network_->libertyCell(inst);
-    if (cell && cell->hasSequentials()) {
-      debugPrint1(debug_, "power_activity", 3, "pending reg %s\n",
-		  network_->pathName(inst));
-      visited_regs_->insert(inst);
-      found_reg_without_activity_ = input_without_activity;
-    }
-  }
-  if (network_->isDriver(pin)) {
-    LibertyPort *port = network_->libertyPort(pin);
-    if (port) {
-      FuncExpr *func = port->function();
-      if (func) {
-	Instance *inst = network_->instance(pin);
-	PwrActivity activity = power_->evalActivity(func, inst);
-	power_->setPinActivity(pin, activity);
-	debugPrint3(debug_, "power_activity", 3, "set %s %.2e %.2f\n",
-		    vertex->name(network_),
-		    activity.activity(),
-		    activity.duty());
+    if (network_->isDriver(pin)) {
+      LibertyPort *port = network_->libertyPort(pin);
+      if (port) {
+	FuncExpr *func = port->function();
+	if (func) {
+	  Instance *inst = network_->instance(pin);
+	  PwrActivity activity = power_->evalActivity(func, inst);
+	  power_->setActivity(pin, activity);
+	  debugPrint3(debug_, "power_activity", 3, "set %s %.2e %.2f\n",
+		      vertex->name(network_),
+		      activity.activity(),
+		      activity.duty());
+	}
       }
     }
   }
@@ -358,11 +415,14 @@ Power::evalActivity(FuncExpr *expr,
       else
 	return PwrActivity(0.0, 0.0, PwrActivityOrigin::constant);
     }
-    Pin *pin = network_->findPin(inst, port->name());
-    if (pin)
-      return findActivity(pin);
-    else
-      return PwrActivity(0.0, 0.0, PwrActivityOrigin::constant);
+    if (port->direction()->isInternal())
+      return findSeqActivity(inst, port);
+    else {
+      Pin *pin = network_->findPin(inst, port);
+      if (pin)
+	return findActivity(pin);
+    }
+    return PwrActivity(0.0, 0.0, PwrActivityOrigin::constant);
   }
   case FuncExpr::op_not: {
     PwrActivity activity1 = evalActivity(expr->left(), inst,
@@ -424,14 +484,21 @@ Power::preamble()
 void
 Power::ensureActivities()
 {
+  // No need to propagate activites if global activity is set.
   if (!global_activity_.isSet()) {
     if (!activities_valid_) {
+      // Clear existing activities.
+      activity_map_.clear();
+      seq_activity_map_.clear();
+
       ActivitySrchPred activity_srch_pred(this);
       BfsFwdIterator bfs(BfsIndex::other, &activity_srch_pred, this);
       seedActivities(bfs);
       PropActivityVisitor visitor(this, &bfs);
       visitor.init();
+      // Propagate activities through combinational logic.
       bfs.visit(levelize_->maxLevel(), &visitor);
+      // Propagate activiities through registers.
       while (visitor.foundRegWithoutActivity()) {
 	InstanceSet *regs = visitor.stealVisitedRegs();
 	InstanceSet::Iterator reg_iter(regs);
@@ -441,7 +508,10 @@ Power::ensureActivities()
 	  seedRegOutputActivities(reg, bfs);
 	}
 	delete regs;
+
 	visitor.init();
+	// Propagate register output activities through
+	// combinational logic.
 	bfs.visit(levelize_->maxLevel(), &visitor);
       }
       activities_valid_ = true;
@@ -456,14 +526,14 @@ Power::seedActivities(BfsFwdIterator &bfs)
     const Pin *pin = vertex->pin();
     // Clock activities are baked in.
     if (!sdc_->isLeafPinClock(pin)
-	&& network_->direction(pin) != PortDirection::internal()) {
+	&& !network_->direction(pin)->isInternal()) {
       debugPrint1(debug_, "power_activity", 3, "seed %s\n",
 		  vertex->name(network_));
-      PwrActivity &activity = pinActivity(pin);
-      PwrActivityOrigin origin = activity.origin();
-      // Default inputs without explicit activities to the input default.
-      if (origin != PwrActivityOrigin::user)
-	setPinActivity(pin, input_activity_);
+      if (hasUserActivity(pin))
+	setActivity(pin, userActivity(pin));
+      else
+	// Default inputs without explicit activities to the input default.
+	setActivity(pin, input_activity_);
       Vertex *vertex = graph_->pinDrvrVertex(pin);
       bfs.enqueueAdjacentVertices(vertex);
     }
@@ -484,9 +554,9 @@ Power::seedRegOutputActivities(const Instance *inst,
     // the sequential internal pins (IQ, IQN).
     InstancePinIterator *pin_iter = network_->pinIterator(inst);
     while (pin_iter->hasNext()) {
-      auto pin = pin_iter->next();
-      auto port = network_->libertyPort(pin);
-      auto func = port->function();
+      Pin *pin = pin_iter->next();
+      LibertyPort *port = network_->libertyPort(pin);
+      FuncExpr *func = port->function();
       if (func) {
 	Vertex *vertex = graph_->pinDrvrVertex(pin);
 	if (func->port() == seq->output()
@@ -507,15 +577,12 @@ Power::seedRegOutputActivities(const Instance *reg,
 			       LibertyPort *output,
 			       bool invert)
 {
-  const Pin *pin = network_->findPin(reg, output);
-  if (pin) {
-    PwrActivity activity = evalActivity(seq->data(), reg);
-    if (invert)
-      activity.set(activity.activity(),
-		   1.0 - activity.duty(),
-		   activity.origin());
-    setPinActivity(pin, activity);
-  }
+  PwrActivity activity = evalActivity(seq->data(), reg);
+  if (invert)
+    activity.set(activity.activity(),
+		 1.0 - activity.duty(),
+		 activity.origin());
+  setSeqActivity(reg, output, activity);
 }
 
 ////////////////////////////////////////////////////////////////
@@ -597,7 +664,7 @@ Power::findInputInternalPower(const Pin *pin,
       for (auto rf : RiseFall::range()) {
 	float slew = delayAsFloat(graph_->slew(vertex, rf,
 					       dcalc_ap->index()));
-	if (!fuzzyInf(slew)) {
+	if (!delayInf(slew)) {
 	  float table_energy = pwr->power(rf, pvt, slew, load_cap);
 	  energy += table_energy;
 	  tr_count++;
@@ -735,7 +802,7 @@ Power::findOutputInternalPower(const Pin *to_pin,
 	? delayAsFloat(graph_->slew(from_vertex, from_rf,
 				    dcalc_ap->index()))
 	: 0.0;
-      if (!fuzzyInf(slew)) {
+      if (!delayInf(slew)) {
 	float table_energy = pwr->power(to_rf, pvt, slew, load_cap);
 	energy += table_energy;
 	tr_count++;
@@ -951,12 +1018,24 @@ Power::findActivity(const Pin *pin)
     return PwrActivity(2.0, 0.5, PwrActivityOrigin::clock);
   else if (global_activity_.isSet())
     return global_activity_;
-  else {
-    if (activity_map_.hasKey(pin)) {
-      PwrActivity &activity = activity_map_[pin];
-      if (activity.origin() != PwrActivityOrigin::unknown)
-	return activity;
-    }
+  else if (activity_map_.hasKey(pin)) {
+    PwrActivity &activity = activity_map_[pin];
+    if (activity.origin() != PwrActivityOrigin::unknown)
+      return activity;
+  }
+  return input_activity_;
+}
+
+PwrActivity
+Power::findSeqActivity(const Instance *inst,
+		       LibertyPort *port)
+{
+  if (global_activity_.isSet())
+    return global_activity_;
+  else if (hasSeqActivity(inst, port)) {
+    PwrActivity activity = seqActivity(inst, port);
+    if (activity.origin() != PwrActivityOrigin::unknown)
+      return activity;
   }
   return input_activity_;
 }
diff --git a/include/sta/Power.hh b/search/Power.hh
similarity index 75%
rename from include/sta/Power.hh
rename to search/Power.hh
index 12625a5e..ec51b5d8 100644
--- a/include/sta/Power.hh
+++ b/search/Power.hh
@@ -16,58 +16,47 @@
 
 #pragma once
 
-#include "Sta.hh"
+#include <utility>
+
+#include "UnorderedMap.hh"
+#include "Network.hh"
+#include "SdcClass.hh"
+#include "PowerClass.hh"
+#include "StaState.hh"
 
 namespace sta {
 
-class PowerResult;
-class PwrActivity;
+class Sta;
+class Corner;
+class DcalcAnalysisPt;
 class PropActivityVisitor;
 class BfsFwdIterator;
 
-typedef UnorderedMap<const Pin*,PwrActivity> PwrActivityMap;
+typedef std::pair<const Instance*, LibertyPort*> SeqPin;
 
-enum class PwrActivityOrigin
-{
- global,
- input,
- user,
- propagated,
- clock,
- constant,
- defaulted,
- unknown
-};
-
-class PwrActivity
+class SeqPinHash
 {
 public:
-  PwrActivity();
-  PwrActivity(float activity,
-		float duty,
-		PwrActivityOrigin origin);
-  float activity() const { return activity_; }
-  float duty() const { return duty_; }
-  PwrActivityOrigin origin() { return origin_; }
-  const char *originName() const;
-  void set(float activity,
-	   float duty,
-	   PwrActivityOrigin origin);
-  bool isSet() const;
-
-private:
-  // In general activity is per clock cycle, NOT per second.
-  float activity_;
-  float duty_;
-  PwrActivityOrigin origin_;
+  size_t operator()(const SeqPin &pin) const;
 };
 
+class SeqPinEqual
+{
+public:
+  bool operator()(const SeqPin &pin1,
+		  const SeqPin &pin2) const;
+};
+
+typedef UnorderedMap<const Pin*,PwrActivity> PwrActivityMap;
+typedef UnorderedMap<SeqPin, PwrActivity,
+		     SeqPinHash, SeqPinEqual> PwrSeqActivityMap;
+
 // The Power class has access to Sta components directly for
 // convenience but also requires access to the Sta class member functions.
 class Power : public StaState
 {
 public:
-  Power(Sta *sta);
+  Power(StaState *sta);
   void power(const Corner *corner,
 	     // Return values.
 	     PowerResult &total,
@@ -86,20 +75,29 @@ public:
   void setInputPortActivity(const Port *input_port,
 			    float activity,
 			    float duty);
-  PwrActivity &pinActivity(const Pin *pin);
-  bool hasPinActivity(const Pin *pin);
-  void setPinActivity(const Pin *pin,
-		      PwrActivity &activity);
-  void setPinActivity(const Pin *pin,
-		      float activity,
-		      float duty,
-		      PwrActivityOrigin origin);
+  PwrActivity &activity(const Pin *pin);
+  void setUserActivity(const Pin *pin,
+		       float activity,
+		       float duty,
+		       PwrActivityOrigin origin);
   // Activity is toggles per second.
   PwrActivity findClkedActivity(const Pin *pin);
 
 protected:
   void preamble();
   void ensureActivities();
+  bool hasUserActivity(const Pin *pin);
+  PwrActivity &userActivity(const Pin *pin);
+  void setSeqActivity(const Instance *reg,
+		      LibertyPort *output,
+		      PwrActivity &activity);
+  bool hasSeqActivity(const Instance *reg,
+		      LibertyPort *output);
+  PwrActivity seqActivity(const Instance *reg,
+			  LibertyPort *output);
+  bool hasActivity(const Pin *pin);
+  void setActivity(const Pin *pin,
+		   PwrActivity &activity);
 
   void power(const Instance *inst,
 	     LibertyCell *cell,
@@ -140,6 +138,8 @@ protected:
   PwrActivity findClkedActivity(const Pin *pin,
 				const Clock *inst_clk);
   PwrActivity findActivity(const Pin *pin);
+  PwrActivity findSeqActivity(const Instance *inst,
+			      LibertyPort *port);
   float portVoltage(LibertyCell *cell,
 		    const LibertyPort *port,
 		    const DcalcAnalysisPt *dcalc_ap);
@@ -169,29 +169,19 @@ protected:
 				     const LibertyPort *cofactor_port);
 
 private:
+  // Port/pin activities set by set_pin_activity.
+  // set_pin_activity -global
   PwrActivity global_activity_;
+  // set_pin_activity -input
   PwrActivity input_activity_;
+  // set_pin_activity -input_ports -pins
+  PwrActivityMap user_activity_map_;
+  // Propagated activities.
   PwrActivityMap activity_map_;
+  PwrSeqActivityMap seq_activity_map_;
   bool activities_valid_;
 
   friend class PropActivityVisitor;
 };
 
-class PowerResult
-{
-public:
-  PowerResult();
-  void clear();
-  float &internal() { return internal_; }
-  float &switching() { return switching_; }
-  float &leakage() { return leakage_; }
-  float total() const;
-  void incr(PowerResult &result);
-  
-private:
-  float internal_;
-  float switching_;
-  float leakage_;
-};
-
 } // namespace
diff --git a/search/Property.cc b/search/Property.cc
index 2877fc86..d56a1447 100644
--- a/search/Property.cc
+++ b/search/Property.cc
@@ -36,6 +36,7 @@
 namespace sta {
 
 using std::string;
+using std::max;
 
 static PropertyValue
 pinSlewProperty(const Pin *pin,
@@ -566,6 +567,8 @@ getProperty(const LibertyCell *cell,
     return PropertyValue(cell->libertyLibrary());
   else if (stringEqual(property, "is_buffer"))
     return PropertyValue(cell->isBuffer());
+  else if (stringEqual(property, "is_inverter"))
+    return PropertyValue(cell->isInverter());
   else if (stringEqual(property, "dont_use"))
     return PropertyValue(cell->dontUse());
   else
@@ -686,6 +689,13 @@ getProperty(const LibertyPort *port,
     float cap = port->capacitance(RiseFall::rise(), MinMax::max());
     return PropertyValue(sta->units()->capacitanceUnit()->asString(cap, 6));
   }
+  else if (stringEqual(property, "is_register_clock"))
+    return PropertyValue(port->isRegClk());
+  else if (stringEqual(property, "drive_resistance")) {
+    float drive = max(port->driveResistance(RiseFall::rise(), MinMax::max()),
+		      port->driveResistance(RiseFall::fall(), MinMax::max()));
+    return PropertyValue(drive);
+  }
   else if (stringEqual(property, "drive_resistance_rise_min"))
     return PropertyValue(port->driveResistance(RiseFall::rise(),
 					       MinMax::min()));
@@ -732,13 +742,17 @@ getProperty(const Pin *pin,
 	    Sta *sta)
 {
   auto network = sta->cmdNetwork();
-  if (stringEqual(property, "direction"))
-    return PropertyValue(network->direction(pin)->name());
-  else if (stringEqual(property, "name")
-	   || stringEqual(property, "full_name"))
-    return PropertyValue(network->pathName(pin));
-  else if (stringEqual(property, "lib_pin_name"))
+  if (stringEqual(property, "name")
+      || stringEqual(property, "lib_pin_name"))
     return PropertyValue(network->portName(pin));
+  else if (stringEqual(property, "full_name"))
+    return PropertyValue(network->pathName(pin));
+  else if (stringEqual(property, "direction"))
+    return PropertyValue(network->direction(pin)->name());
+  else if (stringEqual(property, "is_register_clock")) {
+    const LibertyPort *port = network->libertyPort(pin);
+    return PropertyValue(port && port->isRegClk());
+  }
   else if (stringEqual(property, "clocks")) {
     ClockSet clks;
     sta->clocks(pin, clks);
@@ -793,12 +807,12 @@ pinSlewProperty(const Pin *pin,
   Slew slew = min_max->initValue();
   if (vertex) {
     Slew vertex_slew = sta->vertexSlew(vertex, rf, min_max);
-    if (fuzzyGreater(vertex_slew, slew, min_max))
+    if (delayGreater(vertex_slew, slew, min_max, sta))
       slew = vertex_slew;
   }
   if (bidirect_drvr_vertex) {
     Slew vertex_slew = sta->vertexSlew(bidirect_drvr_vertex, rf, min_max);
-    if (fuzzyGreater(vertex_slew, slew, min_max))
+    if (delayGreater(vertex_slew, slew, min_max, sta))
       slew = vertex_slew;
   }
   return PropertyValue(delayPropertyValue(slew, sta));
@@ -871,9 +885,9 @@ edgeDelayProperty(Edge *edge,
 	ArcDelay arc_delay = sta->arcDelay(edge, arc, dcalc_ap);
 	if (!delay_exists
 	    || ((min_max == MinMax::max()
-		 && arc_delay > delay)
+		 && delayGreater(arc_delay, delay, sta))
 		|| (min_max == MinMax::min()
-		    && arc_delay < delay)))
+		    && delayLess(arc_delay, delay, sta))))
 	  delay = arc_delay;
       }
     }
@@ -916,7 +930,9 @@ getProperty(Clock *clk,
   else if (stringEqual(property, "sources"))
     return PropertyValue(&clk->pins());
   else if (stringEqual(property, "propagated"))
-    return PropertyValue(clk->isPropagated() ? "1" : "0");
+    return PropertyValue(clk->isPropagated());
+  else if (stringEqual(property, "is_generated"))
+    return PropertyValue(clk->isGenerated());
   else
     throw PropertyUnknown("clock", property);
 }
diff --git a/search/ReportPath.cc b/search/ReportPath.cc
index 07b6e3d8..367d5c27 100644
--- a/search/ReportPath.cc
+++ b/search/ReportPath.cc
@@ -578,7 +578,7 @@ ReportPath::reportFull(const PathEndLatchCheck *end,
   else
     reportTgtClk(end, result);
 
-  if (borrow >= 0.0)
+  if (delayGreaterEqual(borrow, 0.0, this))
     reportLine("time borrowed from endpoint", borrow, req_time,
 	       early_late, result);
   else
@@ -644,7 +644,7 @@ ReportPath::reportBorrowing(const PathEndLatchCheck *end,
     if (tgt_clk_path->clkInfo(search_)->isPropagated()) {
       auto width_msg = stdstrPrint("%s nominal pulse width", tgt_clk_name.c_str());
       reportLineTotal(width_msg.c_str(), nom_pulse_width, early_late, result);
-      if (!fuzzyZero(latency_diff))
+      if (!delayZero(latency_diff))
 	reportLineTotalMinus("clock latency difference", latency_diff,
 			     early_late, result);
     }
@@ -655,19 +655,19 @@ ReportPath::reportBorrowing(const PathEndLatchCheck *end,
     ArcDelay margin = end->margin(this);
     reportLineTotalMinus("library setup time", margin, early_late, result);
     reportDashLineTotal(result);
-    if (!fuzzyZero(crpr_diff))
+    if (!delayZero(crpr_diff))
       reportLineTotalMinus("CRPR difference", crpr_diff, early_late, result);
     reportLineTotal("max time borrow", max_borrow, early_late, result);
   }
-  if (fuzzyGreater(borrow, delay_zero)
+  if (delayGreater(borrow, delay_zero, this)
       && (!fuzzyZero(open_uncertainty)
-	  || !fuzzyZero(open_crpr))) {
+	  || !delayZero(open_crpr))) {
     reportDashLineTotal(result);
     reportLineTotal("actual time borrow", borrow, early_late, result);
     if (!fuzzyZero(open_uncertainty))
       reportLineTotal("open edge uncertainty", open_uncertainty,
 		      early_late, result);
-    if (!fuzzyZero(open_crpr))
+    if (!delayZero(open_crpr))
       reportLineTotal("open edge CRPR", open_crpr, early_late, result);
     reportDashLineTotal(result);
     reportLineTotal("time given to startpoint", time_given_to_startpoint,
@@ -705,12 +705,16 @@ void
 ReportPath::reportEndpoint(const PathEndPathDelay *end,
 			   string &result)
 {
-  Instance *inst = network_->instance(end->vertex(this)->pin());
-  const char *inst_name = cmd_network_->pathName(inst);
-  string clk_name = tgtClkName(end);
-  const char *reg_desc = clkRegLatchDesc(end);
-  auto reason = stdstrPrint("%s clocked by %s", reg_desc, clk_name.c_str());
-  reportEndpoint(inst_name, reason, result);
+  if (end->hasOutputDelay())
+    reportEndpointOutputDelay(end, result);
+  else {
+    Instance *inst = network_->instance(end->vertex(this)->pin());
+    const char *inst_name = cmd_network_->pathName(inst);
+    string clk_name = tgtClkName(end);
+    const char *reg_desc = clkRegLatchDesc(end);
+    auto reason = stdstrPrint("%s clocked by %s", reg_desc, clk_name.c_str());
+    reportEndpoint(inst_name, reason, result);
+  }
 }
 
 void
@@ -746,18 +750,16 @@ ReportPath::reportFull(const PathEndPathDelay *end,
   float delay = path_delay->delay();
   reportLine(delay_msg.c_str(), delay, delay, early_late, result);
   if (!path_delay->ignoreClkLatency()) {
-    const Path *tgt_clk_path = end->targetClkPath();
-    if (tgt_clk_path) {
-      float delay = 0.0;
-      if (path_delay)
-	delay = path_delay->delay();
+    Clock *tgt_clk = end->targetClk(this);
+    if (tgt_clk) {
+      const Path *tgt_clk_path = end->targetClkPath();
       if (reportClkPath()
-	  && isPropagated(tgt_clk_path))
+	  && isPropagated(tgt_clk_path, tgt_clk))
 	reportTgtClk(end, delay, result);
       else {
 	Arrival tgt_clk_delay = end->targetClkDelay(this);
 	Arrival tgt_clk_arrival = delay + tgt_clk_delay;
-	if (!fuzzyZero(tgt_clk_delay))
+	if (!delayZero(tgt_clk_delay))
 	  reportLine(clkNetworkDelayIdealProp(isPropagated(tgt_clk_path)),
 		     tgt_clk_delay, tgt_clk_arrival, early_late, result);
 	reportClkUncertainty(end, tgt_clk_arrival, result);
@@ -832,6 +834,13 @@ ReportPath::reportFull(const PathEndOutputDelay *end,
 void
 ReportPath::reportEndpoint(const PathEndOutputDelay *end,
 			   string &result)
+{
+  reportEndpointOutputDelay(end, result);
+}
+
+void
+ReportPath::reportEndpointOutputDelay(const PathEndClkConstrained *end,
+				      string &result)
 {
   Vertex *vertex = end->vertex(this);
   Pin *pin = vertex->pin();
@@ -851,6 +860,7 @@ ReportPath::reportEndpoint(const PathEndOutputDelay *end,
     if (tgt_clk) {
       string clk_name = tgtClkName(end);
       auto reason = stdstrPrint("internal path endpoint clocked by %s", clk_name.c_str());
+
       reportEndpoint(pin_name, reason, result);
     }
     else
@@ -937,8 +947,8 @@ ReportPath::reportFull(const PathEndDataCheck *end,
   reportShort(end, expanded, result);
   reportSrcPathArrival(end, expanded, result);
 
-  // Capture/target clock path reporting resembles both source (reportSrcPath)
-  // and target (reportTgtClk) clocks. 
+  // Data check target clock path reporting resembles 
+  // both source (reportSrcPath) and target (reportTgtClk) clocks. 
   // It is like a source because it can be a non-clock path.
   // It is like a target because crpr and uncertainty are reported.
   // It is always propagated, even if the clock is ideal.
@@ -950,12 +960,14 @@ ReportPath::reportFull(const PathEndDataCheck *end,
     float src_offset = end->sourceClkOffset(this);
     Delay clk_delay = end->targetClkDelay(this);
     Arrival clk_arrival = end->targetClkArrival(this);
-    float offset = delayAsFloat(clk_arrival - clk_delay + src_offset);
+    ClockEdge *tgt_clk_edge = end->targetClkEdge(this);
+    float prev = delayAsFloat(clk_arrival) + src_offset;
+    float offset = prev - delayAsFloat(clk_delay) - tgt_clk_edge->time();
     reportPath5(data_clk_path, clk_expanded, clk_expanded.startIndex(),
 		clk_expanded.size() - 1,
 		data_clk_path->clkInfo(search_)->isPropagated(), false,
 		// Delay to startpoint is already included.
-		clk_arrival + src_offset, offset, result);
+		prev, offset, result);
   }
   reportRequired(end, checkRoleReason(end), result);
   reportSlack(end, result);
@@ -2040,13 +2052,24 @@ ReportPath::reportSrcClkAndPath(const Path *path,
       else if (clk_used_as_data) {
 	reportClkLine(clk, clk_name.c_str(), clk_end_rf, clk_time,
 		      early_late, result);
- 	if (clk_insertion > 0.0)
+ 	if (delayGreater(clk_insertion, 0.0, this))
 	  reportClkSrcLatency(clk_insertion, clk_time, early_late, result);
-	reportPath1(path, expanded, true, time_offset, result);
+	if (reportClkPath())
+	  reportPath1(path, expanded, true, time_offset, result);
+	else {
+	  Arrival clk_arrival = clk_end_time;
+	  Arrival end_arrival = path->arrival(this) + time_offset;
+	  Delay clk_delay = end_arrival - clk_arrival;
+	  reportLine("clock network delay", clk_delay,
+		     end_arrival, early_late, result);
+	  Vertex *end_vertex = path->vertex(this);
+	  reportLine(descriptionField(end_vertex).c_str(),
+		     end_arrival, early_late, clk_end_rf, result);
+	}
       }
       else {
 	if (is_path_delay) {
-	  if (clk_delay > 0.0)
+	  if (delayGreater(clk_delay, 0.0, this))
 	    reportLine(clkNetworkDelayIdealProp(is_prop), clk_delay,
 		       clk_end_time, early_late, result);
 	}
@@ -2493,6 +2516,27 @@ ReportPath::reportPath(const PathEnd *end,
 void
 ReportPath::reportPath(const Path *path,
 		       string &result)
+{
+  switch (format_) {
+  case ReportPathFormat::full:
+  case ReportPathFormat::full_clock:
+  case ReportPathFormat::full_clock_expanded:
+    reportPathFull(path, result);
+    break;
+  case ReportPathFormat::json:
+    reportPathJson(path, result);
+    break;
+  case ReportPathFormat::summary:
+  case ReportPathFormat::slack_only:
+  default:
+    internalError("unsupported path type");
+    break;
+  }
+}
+
+void
+ReportPath::reportPathFull(const Path *path,
+			   string &result)
 {
   reportPathHeader(result);
   PathExpanded expanded(path, this);
@@ -2500,6 +2544,50 @@ ReportPath::reportPath(const Path *path,
 		      false, result);
 }
 
+void
+ReportPath::reportPathJson(const Path *path,
+			   string &result)
+{
+  result += "{ \"path\": [\n";
+  PathExpanded expanded(path, this);
+  for (auto i = expanded.startIndex(); i < expanded.size(); i++) {
+    PathRef *path = expanded.path(i);
+    const Pin *pin = path->vertex(this)->pin();
+    result += "    {\n";
+    result += "       \"pin\": \"";
+    result += network_->pathName(pin);
+    result += "\",\n";
+
+    double x, y;
+    bool exists;
+    string tmp;
+    network_->location(pin, x, y, exists);
+    if (exists) {
+      result += "       \"x\": ";
+      stringPrint(tmp, "%.9f", x);
+      result += tmp + ",\n";
+      result += "       \"y\": ";
+      stringPrint(tmp, "%.9f", y);
+      result += tmp + ",\n";
+    }
+
+    result += "       \"arrival\": ";
+    stringPrint(tmp, "%.3e", delayAsFloat(path->arrival(this)));
+    result += tmp + ",\n";
+    
+    result += "       \"slew\": ";
+    stringPrint(tmp, "%.3e", delayAsFloat(path->slew(this)));
+    result += tmp + "\n";
+
+    result += "    }";
+    if (i < expanded.size() - 1)
+      result += ",";
+    result += "\n";
+  }
+  result += "  ]\n";
+  result += "}\n";
+}
+
 void
 ReportPath::reportPath1(const Path *path,
 			PathExpanded &expanded,
@@ -2527,7 +2615,7 @@ ReportPath::reportPath1(const Path *path,
       }
       Arrival time = latch_enable_time + latch_time_given;
       Arrival incr = latch_time_given;
-      if (incr >= 0.0)
+      if (delayGreaterEqual(incr, 0.0, this))
 	reportLine("time given to startpoint", incr, time, early_late, result);
       else
 	reportLine("time borrowed from startpoint", incr, time,
diff --git a/search/ReportPath.hh b/search/ReportPath.hh
index 8f24cc9d..3fda967c 100644
--- a/search/ReportPath.hh
+++ b/search/ReportPath.hh
@@ -63,6 +63,7 @@ public:
   void reportPathEnd(PathEnd *end,
 		     PathEnd *prev_end);
   void reportPathEnds(PathEndSeq *ends);
+  // for debugging
   void reportPath(const Path *path);
 
   void reportShort(const PathEndUnconstrained *end,
@@ -203,6 +204,8 @@ protected:
 		   string &result);
   void reportEndpoint(const PathEndOutputDelay *end,
 		      string &result);
+  void reportEndpointOutputDelay(const PathEndClkConstrained *end,
+				 string &result);
   void reportEndpoint(const PathEndPathDelay *end,
 		      string &result);
   void reportEndpoint(const PathEndGatedClock *end,
@@ -339,6 +342,10 @@ protected:
 		  string &result);
   void reportPath(const Path *path,
 		  string &result);
+  void reportPathFull(const Path *path,
+		      string &result);
+  void reportPathJson(const Path *path,
+		      string &result);
   void reportPathHeader(string &result);
   void reportPath1(const Path *path,
 		   PathExpanded &expanded,
diff --git a/search/Search.cc b/search/Search.cc
index e585456b..48c7afe1 100644
--- a/search/Search.cc
+++ b/search/Search.cc
@@ -1194,7 +1194,7 @@ Search::arrivalsChanged(Vertex *vertex,
       bool arrival_exists2;
       tag_bldr->tagArrival(tag1, arrival2, arrival_exists2);
       if (!arrival_exists2
-	  || !fuzzyEqual(arrival1, arrival2))
+	  || !delayEqual(arrival1, arrival2))
 	return true;
     }
     return false;
@@ -1238,7 +1238,7 @@ ArrivalVisitor::visitFromToPath(const Pin *,
   Tag *tag_match;
   tag_bldr_->tagMatchArrival(to_tag, tag_match, arrival, arrival_index);
   if (tag_match == nullptr
-      || fuzzyGreater(to_arrival, arrival, min_max)) {
+      || delayGreater(to_arrival, arrival, min_max, sta_)) {
     debugPrint5(debug, "search", 3, "   %s + %s = %s %s %s\n",
 		delayAsString(from_path->arrival(sta_), sta_),
 		delayAsString(arc_delay, sta_),
@@ -1258,7 +1258,7 @@ ArrivalVisitor::visitFromToPath(const Pin *,
       tag_bldr_no_crpr_->tagMatchArrival(to_tag, tag_match,
 					 arrival, arrival_index);
       if (tag_match == nullptr
-	  || fuzzyGreater(to_arrival, arrival, min_max)) {
+	  || delayGreater(to_arrival, arrival, min_max, sta_)) {
 	tag_bldr_no_crpr_->setMatchArrival(to_tag, tag_match,
 					   to_arrival, arrival_index,
 					   &prev_path);
@@ -1300,7 +1300,7 @@ ArrivalVisitor::pruneCrprArrivals()
 		    delayAsString(max_crpr, sta_),
 		    delayAsString(max_arrival_max_crpr, sta_));
 	Arrival arrival = tag_bldr_->arrival(arrival_index);
-	if (fuzzyGreater(max_arrival_max_crpr, arrival, min_max)) {
+	if (delayGreater(max_arrival_max_crpr, arrival, min_max, sta_)) {
 	  debugPrint1(debug, "search", 3, "  pruned %s\n",
 		      tag->asString(sta_));
 	  tag_bldr_->deleteArrival(tag);
@@ -2207,7 +2207,7 @@ PathVisitor::visitFromPath(const Pin *from_pin,
   }
   else {
     arc_delay = search->deratedDelay(from_vertex, arc, edge, false, path_ap);
-    if (!fuzzyEqual(arc_delay, min_max->initValue())) {
+    if (!delayEqual(arc_delay, min_max->initValue())) {
       to_arrival = from_arrival + arc_delay;
       to_tag = search->thruTag(from_tag, edge, to_rf, min_max, path_ap);
     }
@@ -3254,7 +3254,7 @@ FindEndRequiredVisitor::visit(PathEnd *path_end)
     bool arrival_exists;
     path.arrivalIndex(arrival_index, arrival_exists);
     Required required = path_end->requiredTime(sta_);
-    required_cmp_->requiredSet(arrival_index, required, req_min);
+    required_cmp_->requiredSet(arrival_index, required, req_min, sta_);
   }
 }
 
@@ -3319,9 +3319,10 @@ RequiredCmp::requiredsInit(Vertex *vertex,
 void
 RequiredCmp::requiredSet(int arrival_index,
 			 Required required,
-			 const MinMax *min_max)
+			 const MinMax *min_max,
+			 const StaState *sta)
 {
-  if (fuzzyGreater(required, requireds_[arrival_index], min_max)) {
+  if (delayGreater(required, requireds_[arrival_index], min_max, sta)) {
     requireds_[arrival_index] = required;
     have_requireds_ = true;
   }
@@ -3346,7 +3347,7 @@ RequiredCmp::requiredsSave(Vertex *vertex,
       Required req = requireds_[arrival_index];
       if (prev_reqs) {
 	Required prev_req = path->required(sta);
-	if (!fuzzyEqual(prev_req, req)) {
+	if (!delayEqual(prev_req, req)) {
 	  debugPrint2(debug, "search", 3, "required save %s -> %s\n",
 		      delayAsString(prev_req, sta),
 		      delayAsString(req, sta));
@@ -3463,7 +3464,7 @@ RequiredVisitor::visitFromToPath(const Pin *,
 		  delayAsString(from_required, sta_),
 		  min_max == MinMax::max() ? "<" : ">",
 		  delayAsString(required_cmp_->required(arrival_index), sta_));
-      required_cmp_->requiredSet(arrival_index, from_required, req_min);
+      required_cmp_->requiredSet(arrival_index, from_required, req_min, sta_);
     }
     else {
       if (sta_->search()->crprApproxMissingRequireds()) {
@@ -3487,7 +3488,7 @@ RequiredVisitor::visitFromToPath(const Pin *,
 			min_max == MinMax::max() ? "<" : ">",
 			delayAsString(required_cmp_->required(arrival_index),
 				      sta_));
-	    required_cmp_->requiredSet(arrival_index, from_required, req_min);
+	    required_cmp_->requiredSet(arrival_index, from_required, req_min, sta_);
 	    break;
 	  }
 	}
@@ -3640,7 +3641,7 @@ Search::totalNegativeSlack(const MinMax *min_max)
   for (Corner *corner : *corners_) {
     PathAPIndex path_ap_index = corner->findPathAnalysisPt(min_max)->index();
     Slack tns1 = tns_[path_ap_index];
-    if (tns1 < tns)
+    if (delayLess(tns1, tns, this))
       tns = tns1;
   }
   return tns;
@@ -3735,7 +3736,7 @@ Search::tnsIncr(Vertex *vertex,
 		Slack slack,
 		PathAPIndex path_ap_index)
 {
-  if (fuzzyLess(slack, 0.0)) {
+  if (delayLess(slack, 0.0, this)) {
     debugPrint2(debug_, "tns", 3, "tns+ %s %s\n",
 		delayAsString(slack, this),
 		vertex->name(sdc_network_));
@@ -3754,7 +3755,7 @@ Search::tnsDecr(Vertex *vertex,
   bool found;
   tns_slacks_[path_ap_index].findKey(vertex, slack, found);
   if (found
-      && fuzzyLess(slack, 0.0)) {
+      && delayLess(slack, 0.0, this)) {
     debugPrint2(debug_, "tns", 3, "tns- %s %s\n",
 		delayAsString(slack, this),
 		vertex->name(sdc_network_));
@@ -3880,7 +3881,7 @@ FindEndSlackVisitor::visit(PathEnd *path_end)
     PathRef &path = path_end->pathRef();
     PathAPIndex path_ap_index = path.pathAnalysisPtIndex(sta_);
     Slack slack = path_end->slack(sta_);
-    if (fuzzyLess(slack, slacks_[path_ap_index]))
+    if (delayLess(slack, slacks_[path_ap_index], sta_))
       slacks_[path_ap_index] = slack;
   }
 }
@@ -3907,7 +3908,7 @@ Search::wnsSlacks(Vertex *vertex,
       PathAPIndex path_ap_index = path->pathAnalysisPtIndex(this);
       const Slack path_slack = path->slack(this);
       if (!path->tag(this)->isFilter()
-	  && fuzzyLess(path_slack, slacks[path_ap_index]))
+	  && delayLess(path_slack, slacks[path_ap_index], this))
 	slacks[path_ap_index] = path_slack;
     }
   }
diff --git a/search/Sta.cc b/search/Sta.cc
index 2d7868cb..8063d27e 100644
--- a/search/Sta.cc
+++ b/search/Sta.cc
@@ -16,7 +16,6 @@
 
 #include "Sta.hh"
 
-#include "util/Machine.hh"
 #include "DispatchQueue.hh"
 #include "ReportTcl.hh"
 #include "Debug.hh"
@@ -269,6 +268,7 @@ Sta::Sta() :
   link_make_black_boxes_(true),
   update_genclks_(false),
   equiv_cells_(nullptr),
+  graph_sdc_annotated_(false),
   clk_pins_valid_(false)
 {
 }
@@ -537,6 +537,7 @@ Sta::clear()
   // Constraints reference search filter, so clear search first.
   search_->clear();
   sdc_->clear();
+  graph_sdc_annotated_ = false;
   // corners are NOT cleared because they are used to index liberty files.
   levelize_->clear();
   if (parasitics_)
@@ -570,6 +571,7 @@ Sta::networkChanged()
     check_min_periods_->clear();
   delete graph_;
   graph_ = nullptr;
+  graph_sdc_annotated_ = false;
   current_instance_ = nullptr;
   updateComponentsState();
 }
@@ -1101,37 +1103,12 @@ Sta::removeClock(Clock *clk)
   search_->arrivalsInvalid();
 }
 
-Clock *
-Sta::findClock(const char *name) const
-{
-  return sdc_->findClock(name);
-}
-
-void
-Sta::findClocksMatching(PatternMatch *pattern,
-			ClockSeq *clks) const
-{
-  sdc_->findClocksMatching(pattern, clks);
-}
-
-ClockIterator *
-Sta::clockIterator() const
-{
-  return new ClockIterator(sdc_);
-}
-
 bool
 Sta::isClockSrc(const Pin *pin) const
 {
   return sdc_->isClock(pin);
 }
 
-Clock *
-Sta::defaultArrivalClock() const
-{
-  return sdc_->defaultArrivalClock();
-}
-
 void
 Sta::setPropagatedClock(Clock *clk)
 {
@@ -1200,14 +1177,33 @@ Sta::setClockLatency(Clock *clk,
 		     const MinMaxAll *min_max,
 		     float delay)
 {
+  sdcChangedGraph();
   sdc_->setClockLatency(clk, pin, rf, min_max, delay);
   search_->arrivalsInvalid();
 }
 
+void
+Sta::sdcChangedGraph()
+{
+  if (graph_sdc_annotated_)
+    sdc_->removeGraphAnnotations();
+  graph_sdc_annotated_ = false;
+}
+
+void
+Sta::ensureGraphSdcAnnotated()
+{
+  if (!graph_sdc_annotated_) {
+    sdc_->annotateGraph();
+    graph_sdc_annotated_ = true;
+  }
+}
+
 void
 Sta::removeClockLatency(const Clock *clk,
 			const Pin *pin)
 {
+  sdcChangedGraph();
   sdc_->removeClockLatency(clk, pin);
   search_->arrivalsInvalid();
 }
@@ -1398,6 +1394,7 @@ Sta::setDataCheck(Pin *from,
 		  const SetupHoldAll *setup_hold,
 		  float margin)
 {
+  sdcChangedGraph();
   sdc_->setDataCheck(from, from_rf, to, to_rf, clk, setup_hold,margin);
   search_->requiredInvalid(to);
 }
@@ -1419,6 +1416,7 @@ Sta::removeDataCheck(Pin *from,
 void
 Sta::disable(Pin *pin)
 {
+  sdcChangedGraph();
   sdc_->disable(pin);
   // Levelization respects disabled edges.
   levelize_->invalid();
@@ -1429,6 +1427,7 @@ Sta::disable(Pin *pin)
 void
 Sta::removeDisable(Pin *pin)
 {
+  sdcChangedGraph();
   sdc_->removeDisable(pin);
   disableAfter();
   // Levelization respects disabled edges.
@@ -1442,6 +1441,7 @@ Sta::disable(Instance *inst,
 	     LibertyPort *from,
 	     LibertyPort *to)
 {
+  sdcChangedGraph();
   sdc_->disable(inst, from, to);
 
   if (from) {
@@ -1470,6 +1470,7 @@ Sta::removeDisable(Instance *inst,
 		   LibertyPort *from,
 		   LibertyPort *to)
 {
+  sdcChangedGraph();
   sdc_->removeDisable(inst, from, to);
 
   if (from) {
@@ -1514,6 +1515,7 @@ Sta::removeDisable(LibertyCell *cell,
 void
 Sta::disable(LibertyPort *port)
 {
+  sdcChangedGraph();
   sdc_->disable(port);
   disableAfter();
 }
@@ -1521,6 +1523,7 @@ Sta::disable(LibertyPort *port)
 void
 Sta::removeDisable(LibertyPort *port)
 {
+  sdcChangedGraph();
   sdc_->removeDisable(port);
   disableAfter();
 }
@@ -1882,6 +1885,7 @@ Sta::setOutputDelay(Pin *pin,
   sdc_->setOutputDelay(pin, rf, clk, clk_rf, ref_pin,
 		       source_latency_included,network_latency_included,
 		       min_max, add, delay);
+  sdcChangedGraph();
   search_->requiredInvalid(pin);
 }
 
@@ -1893,6 +1897,7 @@ Sta::removeOutputDelay(Pin *pin,
 		       MinMaxAll *min_max)
 {
   sdc_->removeOutputDelay(pin, rf, clk, clk_rf, min_max);
+  sdcChangedGraph();
   search_->arrivalInvalid(pin);
 }
 
@@ -2083,8 +2088,7 @@ Sta::removeConstraints()
   search_->clear();
   sim_->constantsInvalid();
   if (graph_)
-    // Remove graph constraint annotations.
-    sdc_->annotateGraph(false);
+    sdc_->removeGraphAnnotations();
   sdc_->clear();
 }
 
@@ -2403,11 +2407,6 @@ Sta::setCmdCorner(Corner *corner)
   cmd_corner_ = corner;
 }
 
-void
-Sta::setPathMinMax(const MinMaxAll *)
-{
-}
-
 ////////////////////////////////////////////////////////////////
 
 // from/thrus/to are owned and deleted by Search.
@@ -2675,7 +2674,7 @@ Sta::vertexWorstArrivalPath(Vertex *vertex,
     PathVertex *path = path_iter.next();
     Arrival arrival = path->arrival(this);
     if (!path->tag(this)->isGenClkSrcPath()
-	&& fuzzyGreater(arrival, worst_arrival, min_max)) {
+	&& delayGreater(arrival, worst_arrival, min_max, this)) {
       worst_arrival = arrival;
       worst_path.init(path);
     }
@@ -2695,7 +2694,7 @@ Sta::vertexWorstArrivalPath(Vertex *vertex,
     Arrival arrival = path->arrival(this);
     if (path->minMax(this) == min_max
 	&& !path->tag(this)->isGenClkSrcPath()
-	&& fuzzyGreater(arrival, worst_arrival, min_max)) {
+	&& delayGreater(arrival, worst_arrival, min_max, this)) {
       worst_arrival = arrival;
       worst_path.init(path);
     }
@@ -2715,7 +2714,7 @@ Sta::vertexWorstSlackPath(Vertex *vertex,
     PathVertex *path = path_iter.next();
     Slack slack = path->slack(this);
     if (!path->tag(this)->isGenClkSrcPath()
-	&& slack < min_slack) {
+	&& delayLess(slack, min_slack, this)) {
       min_slack = slack;
       worst_path.init(path);
     }
@@ -2736,7 +2735,7 @@ Sta::vertexWorstSlackPath(Vertex *vertex,
     if (path->minMax(this) == min_max
 	&& !path->tag(this)->isGenClkSrcPath()) {
       Slack slack = path->slack(this);
-      if (fuzzyLess(slack, min_slack)) {
+      if (delayLess(slack, min_slack, this)) {
 	min_slack = slack;
 	worst_path.init(path);
       }
@@ -2770,7 +2769,7 @@ Sta::vertexArrival(Vertex *vertex,
     if ((clk_edge == clk_edge_wildcard
 	 || clk_info->clkEdge() == clk_edge)
 	&& !clk_info->isGenClkSrcPath()
-	&& fuzzyGreater(path->arrival(this), arrival, min_max))
+	&& delayGreater(path->arrival(this), arrival, min_max, this))
       arrival = path_arrival;
   }
   return arrival;
@@ -2788,7 +2787,7 @@ Sta::vertexRequired(Vertex *vertex,
     const Path *path = path_iter.next();
     if (path->minMax(this) == min_max) {
       const Required path_required = path->required(this);
-      if (fuzzyGreater(path_required, required, req_min_max))
+      if (delayGreater(path_required, required, req_min_max, this))
 	required = path_required;
     }
   }
@@ -2818,7 +2817,7 @@ Sta::vertexRequired(Vertex *vertex,
     const Required path_required = path->required(this);
     if ((clk_edge == clk_edge_wildcard
 	 || path->clkEdge(search_) == clk_edge)
-	&& fuzzyGreater(path_required, required, min_max))
+	&& delayGreater(path_required, required, min_max, this))
       required = path_required;
   }
   return required;
@@ -2836,7 +2835,8 @@ Sta::netSlack(const Net *net,
     if (network_->isLoad(pin)) {
       Vertex *vertex = graph_->pinLoadVertex(pin);
       Slack pin_slack = vertexSlack(vertex, min_max);
-      slack = min(slack, pin_slack);
+      if (delayLess(pin_slack, slack, this))
+	slack = pin_slack;
     }
   }
   return slack;
@@ -2852,8 +2852,11 @@ Sta::pinSlack(const Pin *pin,
   Slack slack = MinMax::min()->initValue();
   if (vertex)
     slack = vertexSlack(vertex, min_max);
-  if (bidirect_drvr_vertex)
-    slack = min(slack, vertexSlack(bidirect_drvr_vertex, min_max));
+  if (bidirect_drvr_vertex) {
+    Slack slack1 = vertexSlack(bidirect_drvr_vertex, min_max);
+    if (delayLess(slack1, slack, this))
+      slack = slack1;
+  }
   return slack;
 }
 
@@ -2868,8 +2871,11 @@ Sta::pinSlack(const Pin *pin,
   Slack slack = MinMax::min()->initValue();
   if (vertex)
     slack = vertexSlack(vertex, rf, min_max);
-  if (bidirect_drvr_vertex)
-    slack = min(slack, vertexSlack(bidirect_drvr_vertex, rf, min_max));
+  if (bidirect_drvr_vertex) {
+    Slack slack1 = vertexSlack(bidirect_drvr_vertex, rf, min_max);
+    if (delayLess(slack1, slack, this))
+      slack = slack1;
+  }
   return slack;
 }
 
@@ -2885,7 +2891,7 @@ Sta::vertexSlack(Vertex *vertex,
     Path *path = path_iter.next();
     if (path->minMax(this) == min_max) {
       Slack path_slack = path->slack(this);
-      if (path_slack < slack)
+      if (delayLess(path_slack, slack, this))
 	slack = path_slack;
     }
   }
@@ -2903,7 +2909,7 @@ Sta::vertexSlack(Vertex *vertex,
   while (path_iter.hasNext()) {
     Path *path = path_iter.next();
     Slack path_slack = path->slack(this);
-    if (path_slack < slack)
+    if (delayLess(path_slack, slack, this))
       slack = path_slack;
   }
   return slack;
@@ -2942,7 +2948,7 @@ Sta::vertexSlack1(Vertex *vertex,
     Slack path_slack = path->slack(this);
     if ((clk_edge == clk_edge_wildcard
 	 || path->clkEdge(search_) == clk_edge)
-	&& path_slack < slack)
+	&& delayLess(path_slack, slack, this))
       slack = path_slack;
   }
   return slack;
@@ -2964,7 +2970,7 @@ Sta::vertexSlacks(Vertex *vertex,
     Slack path_slack = path->slack(this);
     int rf_index = path->rfIndex(this);
     int mm_index = path->minMax(this)->index();
-    if (path_slack < slacks[rf_index][mm_index])
+    if (delayLess(path_slack, slacks[rf_index][mm_index], this))
       slacks[rf_index][mm_index] = path_slack;
   }
 }
@@ -3159,7 +3165,7 @@ Sta::vertexSlew(Vertex *vertex,
   Slew mm_slew = min_max->initValue();
   for (DcalcAnalysisPt *dcalc_ap : corners_->dcalcAnalysisPts()) {
     Slew slew = graph_->slew(vertex, rf, dcalc_ap->index());
-    if (fuzzyGreater(slew, mm_slew, min_max))
+    if (delayGreater(slew, mm_slew, min_max, this))
       mm_slew = slew;
   }
   return mm_slew;
@@ -3174,7 +3180,6 @@ Sta::ensureGraph()
     makeGraph();
     // Update pointers to graph.
     updateComponentsState();
-    sdc_->annotateGraph(true);
   }
   return graph_;
 }
@@ -3190,6 +3195,7 @@ void
 Sta::ensureLevelized()
 {
   ensureGraph();
+  ensureGraphSdcAnnotated();
   // Need constant propagation before levelization to know edges that
   // are disabled by constants.
   sim_->ensureConstantsPropagated();
@@ -3806,7 +3812,9 @@ Sta::makeInstanceAfter(Instance *inst)
     while (port_iter.hasNext()) {
       LibertyPort *lib_port = port_iter.next();
       Pin *pin = network_->findPin(inst, lib_port);
-      connectPinAfter(pin);
+      // Internal pins may not exist.
+      if (pin)
+	connectPinAfter(pin);
     }
   }
 }
@@ -4392,6 +4400,7 @@ void
 Sta::findRegisterPreamble()
 {
   ensureGraph();
+  ensureGraphSdcAnnotated();
   sim_->ensureConstantsPropagated();
 }
 
@@ -4785,7 +4794,7 @@ bool
 InstanceMaxSlewGreater::operator()(const Instance *inst1,
 				   const Instance *inst2) const
 {
-  return instMaxSlew(inst1) > instMaxSlew(inst2);
+  return delayGreater(instMaxSlew(inst1), instMaxSlew(inst2), sta_);
 }
 
 Slew
@@ -4802,7 +4811,7 @@ InstanceMaxSlewGreater::instMaxSlew(const Instance *inst) const
       for (RiseFall *rf : RiseFall::range()) {
 	for (DcalcAnalysisPt *dcalc_ap : sta_->corners()->dcalcAnalysisPts()) {
 	  Slew slew = graph->slew(vertex, rf, dcalc_ap->index());
-	  if (slew > max_slew)
+	  if (delayGreater(slew, max_slew, sta_))
 	    max_slew = slew;
 	}
       }
@@ -4971,7 +4980,6 @@ Sta::checkFanout(const Pin *pin,
 		 float &limit,
 		 float &slack)
 {
-  checkFanoutLimitPreamble();
   check_fanout_limits_->checkFanout(pin, min_max,
 				    fanout, limit, slack);
 }
@@ -5050,7 +5058,6 @@ Sta::checkCapacitance(const Pin *pin,
 		      float &limit,
 		      float &slack)
 {
-  checkCapacitanceLimitPreamble();
   check_capacitance_limits_->checkCapacitance(pin, corner, min_max,
 					      corner1, rf, capacitance,
 					      limit, slack);
diff --git a/search/VisitPathEnds.cc b/search/VisitPathEnds.cc
index d3bd3da7..99e1152a 100644
--- a/search/VisitPathEnds.cc
+++ b/search/VisitPathEnds.cc
@@ -556,8 +556,8 @@ VisitPathEnds::visitDataCheckEnd1(DataCheck *check,
 	      || exception->isMultiCycle())
 	  && (!filtered
 	      || search_->matchesFilter(path, tgt_clk_edge))) {
-	// No mcp for data checks.
-	PathEndDataCheck path_end(check, path, tgt_clk_path, nullptr, this);
+	MultiCyclePath *mcp=dynamic_cast<MultiCyclePath*>(exception);
+	PathEndDataCheck path_end(check, path, tgt_clk_path, mcp, this);
 	visitor->visit(&path_end);
 	is_constrained = true;
       }
diff --git a/search/WorstSlack.cc b/search/WorstSlack.cc
index bce83e93..f9c0893a 100644
--- a/search/WorstSlack.cc
+++ b/search/WorstSlack.cc
@@ -48,7 +48,7 @@ WorstSlacks::worstSlack(const MinMax *min_max,
     Vertex *worst_vertex1;
     worst_slacks_[path_ap_index].worstSlack(path_ap_index, sta_,
 					    worst_slack1, worst_vertex1);
-    if (fuzzyLess(worst_slack1, worst_slack)) {
+    if (delayLess(worst_slack1, worst_slack, sta_)) {
       worst_slack = worst_slack1;
       worst_vertex = worst_vertex1;
     }
@@ -159,10 +159,10 @@ WorstSlack::initQueue(PathAPIndex path_ap_index,
   while (end_iter.hasNext()) {
     Vertex *vertex = end_iter.next();
     Slack slack = search->wnsSlack(vertex, path_ap_index);
-    if (!fuzzyEqual(slack, slack_init_)) {
-      if (fuzzyLess(slack, worst_slack_))
+    if (!delayEqual(slack, slack_init_)) {
+      if (delayLess(slack, worst_slack_, sta))
 	setWorstSlack(vertex, slack, sta);
-      if (fuzzyLessEqual(slack, slack_threshold_))
+      if (delayLessEqual(slack, slack_threshold_, sta))
 	queue_.insert(vertex);
       int queue_size = queue_.size();
       if (queue_size >= max_queue_size_)
@@ -178,41 +178,43 @@ void
 WorstSlack::sortQueue(PathAPIndex path_ap_index,
 		      const StaState *sta)
 {
-  Search *search = sta->search();
-  const Debug *debug = sta->debug();
-  debugPrint0(debug, "wns", 3, "sort queue\n");
+  if (queue_.size() > 0) {
+    Search *search = sta->search();
+    const Debug *debug = sta->debug();
+    debugPrint0(debug, "wns", 3, "sort queue\n");
 
-  VertexSeq vertices;
-  vertices.reserve(queue_.size());
-  VertexSet::Iterator queue_iter(queue_);
-  while (queue_iter.hasNext()) {
-    Vertex *vertex = queue_iter.next();
-    vertices.push_back(vertex);
+    VertexSeq vertices;
+    vertices.reserve(queue_.size());
+    VertexSet::Iterator queue_iter(queue_);
+    while (queue_iter.hasNext()) {
+      Vertex *vertex = queue_iter.next();
+      vertices.push_back(vertex);
+    }
+    WnsSlackLess slack_less(path_ap_index, sta);
+    sort(vertices, slack_less);
+
+    int vertex_count = vertices.size();
+    int threshold_index = min(min_queue_size_, vertex_count - 1);
+    Vertex *threshold_vertex = vertices[threshold_index];
+    slack_threshold_ = search->wnsSlack(threshold_vertex, path_ap_index);
+    debugPrint1(debug, "wns", 3, "threshold %s\n",
+		delayAsString(slack_threshold_, sta));
+
+    // Reinsert vertices with slack < threshold.
+    queue_.clear();
+    VertexSeq::Iterator queue_iter2(vertices);
+    while (queue_iter2.hasNext()) {
+      Vertex *vertex = queue_iter2.next();
+      Slack slack = search->wnsSlack(vertex, path_ap_index);
+      if (delayGreater(slack, slack_threshold_, sta))
+	break;
+      queue_.insert(vertex);
+    }
+    max_queue_size_ = queue_.size() * 2;
+    Vertex *worst_slack_vertex = vertices[0];
+    Slack worst_slack_slack = search->wnsSlack(worst_slack_vertex, path_ap_index);
+    setWorstSlack(worst_slack_vertex, worst_slack_slack, sta);
   }
-  WnsSlackLess slack_less(path_ap_index, sta);
-  sort(vertices, slack_less);
-
-  int vertex_count = vertices.size();
-  int threshold_index = min(min_queue_size_, vertex_count - 1);
-  Vertex *threshold_vertex = vertices[threshold_index];
-  slack_threshold_ = search->wnsSlack(threshold_vertex, path_ap_index);
-  debugPrint1(debug, "wns", 3, "threshold %s\n",
-	      delayAsString(slack_threshold_, sta));
-
-  // Reinsert vertices with slack < threshold.
-  queue_.clear();
-  VertexSeq::Iterator queue_iter2(vertices);
-  while (queue_iter2.hasNext()) {
-    Vertex *vertex = queue_iter2.next();
-    Slack slack = search->wnsSlack(vertex, path_ap_index);
-    if (fuzzyGreater(slack, slack_threshold_))
-      break;
-    queue_.insert(vertex);
-  }
-  max_queue_size_ = queue_.size() * 2;
-  Vertex *worst_slack_vertex = vertices[0];
-  Slack worst_slack_slack = search->wnsSlack(worst_slack_vertex, path_ap_index);
-  setWorstSlack(worst_slack_vertex, worst_slack_slack, sta);
 }
 
 void
@@ -229,7 +231,7 @@ WorstSlack::findWorstInQueue(PathAPIndex path_ap_index,
   while (queue_iter.hasNext()) {
     Vertex *vertex = queue_iter.next();
     Slack slack = search->wnsSlack(vertex, path_ap_index);
-    if (slack < worst_slack_)
+    if (delayLess(slack, worst_slack_, sta))
       setWorstSlack(vertex, slack, sta);
   }
 }
@@ -246,8 +248,8 @@ WorstSlack::checkQueue(PathAPIndex path_ap_index,
   VertexSet::Iterator end_iter(search->endpoints());
   while (end_iter.hasNext()) {
     Vertex *end = end_iter.next();
-    if (fuzzyLessEqual(search->wnsSlack(end, path_ap_index),
-			    slack_threshold_))
+    if (delayLessEqual(search->wnsSlack(end, path_ap_index),
+		       slack_threshold_, sta))
       ends.push_back(end);
   }
   WnsSlackLess slack_less(path_ap_index, sta);
@@ -259,8 +261,8 @@ WorstSlack::checkQueue(PathAPIndex path_ap_index,
     Vertex *end = end_iter2.next();
     end_set.insert(end);
     if (!queue_.hasKey(end)
-	&& fuzzyLessEqual(search->wnsSlack(end, path_ap_index),
-			       slack_threshold_))
+	&& delayLessEqual(search->wnsSlack(end, path_ap_index),
+			  slack_threshold_, sta))
       report->print("WorstSlack queue missing %s %s < %s\n",
 		    end->name(network),
 		    delayAsString(search->wnsSlack(end, path_ap_index), sta),
@@ -292,14 +294,14 @@ WorstSlack::updateWorstSlack(Vertex *vertex,
   // threads.
   UniqueLock lock(lock_);
   if (worst_vertex_
-      && fuzzyLess(slack, worst_slack_))
+      && delayLess(slack, worst_slack_, sta))
     setWorstSlack(vertex, slack, sta);
   else if (vertex == worst_vertex_)
     // Mark worst slack as unknown (updated by findWorstSlack().
     worst_vertex_ = nullptr;
 
-  if (!fuzzyEqual(slack, slack_init_)
-      && fuzzyLessEqual(slack, slack_threshold_)) {
+  if (!delayEqual(slack, slack_init_)
+      && delayLessEqual(slack, slack_threshold_, sta)) {
     debugPrint2(debug, "wns", 3, "insert %s %s\n",
 		vertex->name(network),
 		delayAsString(slack, sta));
@@ -339,8 +341,9 @@ bool
 WnsSlackLess::operator()(Vertex *vertex1,
 			 Vertex *vertex2)
 {
-  return fuzzyLess(search_->wnsSlack(vertex1, path_ap_index_),
-			search_->wnsSlack(vertex2, path_ap_index_));
+  return delayLess(search_->wnsSlack(vertex1, path_ap_index_),
+		   search_->wnsSlack(vertex2, path_ap_index_),
+		   search_);
 }
 
 } // namespace
diff --git a/tcl/Cmds.tcl b/tcl/Cmds.tcl
index 7a541783..91548b66 100644
--- a/tcl/Cmds.tcl
+++ b/tcl/Cmds.tcl
@@ -45,15 +45,6 @@ proc report_clock1 { clk } {
   }
 }
 
-proc_redirect read_parasitics {
-  variable native
-
-  if { $native } {
-    sta_warn "The read_parasitics command is deprecated. Use read_spef."
-  }
-  eval [concat read_spef $args]
-}
-
 proc check_setup_cmd { cmd cmd_args } {
   parse_key_args $cmd cmd_args keys {} flags {-verbose} 0
   # When nothing is everything.
@@ -1145,6 +1136,12 @@ proc parse_libcell_libport_inst_port_pin_edge_timing_arc_set_arg { objects \
     edges timing_arc_sets
 }
 
+proc parse_libcell_arg { objects } {
+  set libcells {}
+  get_object_args $objects {} libcells {} {} {} {} {} {} {} {}
+  return $libcells
+}
+
 proc parse_libcell_inst_arg { objects libcells_var insts_var } {
   upvar 1 $libcells_var libcells
   upvar 1 $insts_var insts
diff --git a/tcl/Network.tcl b/tcl/Network.tcl
index 352207a2..4dbcb7da 100644
--- a/tcl/Network.tcl
+++ b/tcl/Network.tcl
@@ -382,7 +382,7 @@ proc report_net_pin { pin verbose corner digits } {
 	puts -nonewline [port_capacitance_str $liberty_port $digits]
       }
     }
-    puts ""
+    puts "[pin_location_str $pin]"
   } elseif [$pin is_top_level_port] {
     puts -nonewline " [get_full_name $pin] [pin_direction $pin] port"
     if { $verbose } {
@@ -404,12 +404,23 @@ proc report_net_pin { pin verbose corner digits } {
 	puts -nonewline " pin [capacitances_str $cap_r_min $cap_r_max $cap_f_min $cap_f_max $digits]"
       }
     }
-    puts ""
+    puts "[pin_location_str $pin]"
   } elseif [$pin is_hierarchical] {
     puts " [get_full_name $pin] [pin_direction $pin]"
   }
 }
 
+# Used by report_net
+proc pin_location_str { pin } {
+  set loc [pin_location $pin]
+  if { $loc != "" } {
+    lassign $loc x y
+    return " ([format_distance $x 0], [format_distance $y 0])"
+  } else {
+    return ""
+  }
+}
+
 ################################################################
 
 proc report_pin_ { pin } {
diff --git a/tcl/Power.tcl b/tcl/Power.tcl
index 840801ba..d8bfaaa3 100644
--- a/tcl/Power.tcl
+++ b/tcl/Power.tcl
@@ -247,7 +247,7 @@ proc set_power_activity { args } {
     }
   }
   if { [info exists keys(-pins)] } {
-    set ports [get_pins_error "pins" $keys(-pins)]
+    set pins [get_pins $keys(-pins)]
     foreach pin $pins {
       if { [get_property $pin "direction"] == "input" } {
 	set_power_pin_activity $pin $activity $duty
diff --git a/tcl/Sdc.tcl b/tcl/Sdc.tcl
index 1839abc3..8f2e42c0 100644
--- a/tcl/Sdc.tcl
+++ b/tcl/Sdc.tcl
@@ -502,9 +502,16 @@ proc get_cells { args } {
     if { $args != {} } {
       sta_warn "patterns argument not supported with -of_objects."
     }
-    parse_pin_net_args $keys(-of_objects) pins nets
+    parse_port_pin_net_arg $keys(-of_objects) pins nets
     foreach pin $pins {
-      lappend insts [$pin instance]
+      if { [$pin is_top_level_port] } {
+	set net [get_nets [get_name $pin]]
+	if { $net != "NULL" } {
+	  lappend nets $net
+	}
+      } else {
+	lappend insts [$pin instance]
+      }
     }
     foreach net $nets {
       set pin_iter [$net pin_iterator]
@@ -997,7 +1004,7 @@ proc get_ports { args } {
   return $ports
 }
 
-variable filter_regexp1 {@?([a-zA-Z_]+) +(==|=~) +([0-9a-zA-Z_\*]+)}
+variable filter_regexp1 {@?([a-zA-Z_]+) *(==|=~) *([0-9a-zA-Z_\*]+)}
 variable filter_or_regexp "($filter_regexp1) +\\|\\| +($filter_regexp1)"
 variable filter_and_regexp "($filter_regexp1) +&& +($filter_regexp1)"
 
diff --git a/tcl/Search.tcl b/tcl/Search.tcl
index 23a06b0e..41491223 100644
--- a/tcl/Search.tcl
+++ b/tcl/Search.tcl
@@ -227,7 +227,7 @@ proc parse_report_path_options { cmd args_var default_format
   if [info exists path_options(-format)] {
     set format $path_options(-format)
     set formats {full full_clock full_clock_expanded short \
-		   end slack_only summary}
+		   end slack_only summary json}
     if { [lsearch $formats $format] == -1 } {
       sta_error "-format $format not recognized."
     }
diff --git a/tcl/StaTcl.i b/tcl/StaTcl.i
index 8e6ff2e1..0e4c5f31 100644
--- a/tcl/StaTcl.i
+++ b/tcl/StaTcl.i
@@ -68,17 +68,16 @@
 #include "PathEnd.hh"
 #include "PathGroup.hh"
 #include "PathAnalysisPt.hh"
-#include "Power.hh"
 #include "Property.hh"
 #include "WritePathSpice.hh"
 #include "Search.hh"
 #include "Sta.hh"
-#include "util/Machine.hh"
 #include "search/Tag.hh"
 #include "search/CheckTiming.hh"
 #include "search/CheckMinPulseWidths.hh"
 #include "search/Levelize.hh"
 #include "search/ReportPath.hh"
+#include "search/Power.hh"
 
 namespace sta {
 
@@ -106,6 +105,8 @@ typedef MinMaxAll MinMaxAllNull;
 typedef ClockSet TmpClockSet;
 typedef StringSeq TmpStringSeq;
 
+using std::vector;
+
 class CmdErrorNetworkNotLinked : public Exception
 {
 public:
@@ -188,6 +189,30 @@ tclListSeq(Tcl_Obj *const source,
     return nullptr;
 }
 
+template <class TYPE>
+vector<TYPE> *
+tclListStdSeq(Tcl_Obj *const source,
+	      swig_type_info *swig_type,
+	      Tcl_Interp *interp)
+{
+  int argc;
+  Tcl_Obj **argv;
+
+  if (Tcl_ListObjGetElements(interp, source, &argc, &argv) == TCL_OK
+      && argc > 0) {
+    vector<TYPE> *seq = new vector<TYPE>;
+    for (int i = 0; i < argc; i++) {
+      void *obj;
+      // Ignore returned TCL_ERROR because can't get swig_type_info.
+      SWIG_ConvertPtr(argv[i], &obj, swig_type, false);
+      seq->push_back(reinterpret_cast<TYPE>(obj));
+    }
+    return seq;
+  }
+  else
+    return nullptr;
+}
+
 LibertyLibrarySeq *
 tclListSeqLibertyLibrary(Tcl_Obj *const source,
 			 Tcl_Interp *interp)
@@ -195,11 +220,11 @@ tclListSeqLibertyLibrary(Tcl_Obj *const source,
   return tclListSeq<LibertyLibrary*>(source, SWIGTYPE_p_LibertyLibrary, interp);
 }
 
-LibertyCellSeq *
+vector<LibertyCell*> *
 tclListSeqLibertyCell(Tcl_Obj *const source,
 		      Tcl_Interp *interp)
 {
-  return tclListSeq<LibertyCell*>(source, SWIGTYPE_p_LibertyCell, interp);
+  return tclListStdSeq<LibertyCell*>(source, SWIGTYPE_p_LibertyCell, interp);
 }
 
 template <class TYPE>
@@ -442,6 +467,10 @@ using namespace sta;
   delete cells;
 }
 
+%typemap(in) vector<LibertyCell*> * {
+  $1 = tclListSeqLibertyCell($input, interp);
+}
+
 %typemap(out) LibertyCellSeq* {
   Tcl_Obj *list = Tcl_NewListObj(0, nullptr);
   LibertyCellSeq *cells = $1;
@@ -1065,6 +1094,8 @@ using namespace sta;
     $1 = ReportPathFormat::summary;
   else if (stringEq(arg, "slack_only"))
     $1 = ReportPathFormat::slack_only;
+  else if (stringEq(arg, "json"))
+    $1 = ReportPathFormat::json;
   else {
     tclError(interp, "Error: unknown path type %s.", arg);
     return TCL_ERROR;
@@ -4799,8 +4830,8 @@ set_power_pin_activity(const Pin *pin,
 		       float activity,
 		       float duty)
 {
-  return Sta::sta()->power()->setPinActivity(pin, activity, duty,
-					     PwrActivityOrigin::user);
+  return Sta::sta()->power()->setUserActivity(pin, activity, duty,
+					      PwrActivityOrigin::user);
 }
 
 ////////////////////////////////////////////////////////////////
@@ -5309,6 +5340,20 @@ delays_invalid()
   sta->delaysInvalid();
 }
 
+const char *
+pin_location(Pin *pin)
+{
+  Network *network = cmdNetwork();
+  double x, y;
+  bool exists;
+  network->location(pin, x, y, exists);
+  // return x/y as tcl list
+  if (exists)
+    return sta::stringPrintTmp("%f %f", x, y);
+  else
+    return "";
+}
+
 %} // inline
 
 ////////////////////////////////////////////////////////////////
diff --git a/util/Report.cc b/util/Report.cc
index 0d8d07eb..fea3d287 100644
--- a/util/Report.cc
+++ b/util/Report.cc
@@ -19,7 +19,6 @@
 #include <algorithm> // min
 
 #include "Error.hh"
-#include "Machine.hh"
 
 namespace sta {
 
diff --git a/util/Stats.cc b/util/Stats.cc
index 5b647f63..d27f89f0 100644
--- a/util/Stats.cc
+++ b/util/Stats.cc
@@ -16,9 +16,9 @@
 
 #include "Stats.hh"
 
+#include "Machine.hh"
 #include "StringUtil.hh"
 #include "Debug.hh"
-#include "Machine.hh"
 
 namespace sta {
 
diff --git a/util/StringUtil.cc b/util/StringUtil.cc
index 151b9a08..95f8d13e 100644
--- a/util/StringUtil.cc
+++ b/util/StringUtil.cc
@@ -20,8 +20,8 @@
 #include <ctype.h>
 #include <stdio.h>
 
-#include "Mutex.hh"
 #include "Machine.hh"
+#include "Mutex.hh"
 
 namespace sta {
 
diff --git a/verilog/Verilog.i b/verilog/Verilog.i
index 34f7609a..2d740479 100644
--- a/verilog/Verilog.i
+++ b/verilog/Verilog.i
@@ -51,13 +51,14 @@ delete_verilog_reader()
 
 void
 write_verilog_cmd(const char *filename,
-		  bool sort)
+		  bool sort,
+		  vector<LibertyCell*> *remove_cells)
 {
   // This does NOT want the SDC (cmd) network because it wants
   // to see the sta internal names.
   Sta *sta = Sta::sta();
   Network *network = sta->network();
-  writeVerilog(filename, sort, network);
+  writeVerilog(filename, sort, remove_cells, network);
 }
 
 %} // inline
diff --git a/verilog/Verilog.tcl b/verilog/Verilog.tcl
index 3f46461a..59c5f0a8 100644
--- a/verilog/Verilog.tcl
+++ b/verilog/Verilog.tcl
@@ -19,15 +19,19 @@ namespace eval sta {
 # Defined by SWIG interface Verilog.i.
 define_cmd_args "read_verilog" {filename}
 
-define_cmd_args "write_verilog" {[-sort] filename}
+define_cmd_args "write_verilog" {[-sort] [-remove_cells cells] filename}
 
 proc write_verilog { args } {
-  parse_key_args "write_verilog" args keys {} flags {-sort}
+  parse_key_args "write_verilog" args keys {-remove_cells} flags {-sort}
 
+  set remove_cells {}
+  if { [info exists keys(-remove_cells)] } {
+    set remove_cells [sta::parse_libcell_arg $keys(-remove_cells)]
+  }
   set sort [info exists flags(-sort)]
   check_argc_eq1 "write_verilog" $args
   set filename $args
-  write_verilog_cmd $filename $sort
+  write_verilog_cmd $filename $sort $remove_cells
 }
 
 # sta namespace end
diff --git a/verilog/VerilogWriter.cc b/verilog/VerilogWriter.cc
index 52ffc0f4..36ed2093 100644
--- a/verilog/VerilogWriter.cc
+++ b/verilog/VerilogWriter.cc
@@ -32,6 +32,7 @@ class VerilogWriter
 public:
   VerilogWriter(const char *filename,
 		bool sort,
+		vector<LibertyCell*> *remove_cells,
 		FILE *stream,
 		Network *network);
   void writeModule(Instance *inst);
@@ -54,6 +55,7 @@ protected:
 
   const char *filename_;
   bool sort_;
+  CellSet remove_cells_;
   FILE *stream_;
   Network *network_;
 
@@ -65,12 +67,13 @@ protected:
 void
 writeVerilog(const char *filename,
 	     bool sort,
+	     vector<LibertyCell*> *remove_cells,
 	     Network *network)
 {
   if (network->topInstance()) {
     FILE *stream = fopen(filename, "w");
     if (stream) {
-      VerilogWriter writer(filename, sort, stream, network);
+      VerilogWriter writer(filename, sort, remove_cells, stream, network);
       writer.writeModule(network->topInstance());
       fclose(stream);
     }
@@ -81,6 +84,7 @@ writeVerilog(const char *filename,
 
 VerilogWriter::VerilogWriter(const char *filename,
 			     bool sort,
+			     vector<LibertyCell*> *remove_cells,
 			     FILE *stream,
 			     Network *network) :
   filename_(filename),
@@ -89,6 +93,10 @@ VerilogWriter::VerilogWriter(const char *filename,
   network_(network),
   unconnected_net_index_(1)
 {
+  if (remove_cells) {
+    for(LibertyCell *lib_cell : *remove_cells)
+      remove_cells_.insert(network->cell(lib_cell));
+  }
 }
 
 void
@@ -165,12 +173,20 @@ VerilogWriter::verilogPortDir(PortDirection *dir)
     return "input";
   else if (dir == PortDirection::output())
     return "output";
-  else if (dir == PortDirection::bidirect())
-    return "inout";
   else if (dir == PortDirection::tristate())
     return "output";
-  else
+  else if (dir == PortDirection::bidirect())
+    return "inout";
+  else if (dir == PortDirection::power())
+    return "input";
+  else if (dir == PortDirection::ground())
+    return "input";
+  else if (dir == PortDirection::internal())
     return nullptr;
+  else {
+    internalError("unknown port direction");
+    return nullptr;
+  }
 }
 
 void
@@ -197,23 +213,25 @@ void
 VerilogWriter::writeChild(Instance *child)
 {
   Cell *child_cell = network_->cell(child);
-  const char *child_name = network_->name(child);
-  const char *child_vname = instanceVerilogName(child_name,
-						network_->pathEscape());
-  fprintf(stream_, " %s %s (",
-	  network_->name(child_cell),
-	  child_vname);
-  bool first_port = true;
-  CellPortIterator *port_iter = network_->portIterator(child_cell);
-  while (port_iter->hasNext()) {
-    Port *port = port_iter->next();
-    if (network_->hasMembers(port)) 
-      writeInstBusPin(child, port, first_port);
-    else 
-      writeInstPin(child, port, first_port);
+  if (!remove_cells_.hasKey(child_cell)) {
+    const char *child_name = network_->name(child);
+    const char *child_vname = instanceVerilogName(child_name,
+						  network_->pathEscape());
+    fprintf(stream_, " %s %s (",
+	    network_->name(child_cell),
+	    child_vname);
+    bool first_port = true;
+    CellPortIterator *port_iter = network_->portIterator(child_cell);
+    while (port_iter->hasNext()) {
+      Port *port = port_iter->next();
+      if (network_->hasMembers(port)) 
+	writeInstBusPin(child, port, first_port);
+      else 
+	writeInstPin(child, port, first_port);
+    }
+    delete port_iter;
+    fprintf(stream_, ");\n");
   }
-  delete port_iter;
-  fprintf(stream_, ");\n");
 }
 
 void