From beeb95d8304cfd04358f7d31905516480cccb52d Mon Sep 17 00:00:00 2001
From: James Cherry <cherry@parallaxsw.com>
Date: Sat, 14 Nov 2020 10:34:26 -0700
Subject: [PATCH] Sdc::connectPinAfter minimize work if no hpins

---
 include/sta/Sdc.hh |  2 ++
 sdc/Sdc.cc         | 71 ++++++++++++++++++++++++++++++----------------
 search/Sim.cc      |  3 +-
 3 files changed, 49 insertions(+), 27 deletions(-)

diff --git a/include/sta/Sdc.hh b/include/sta/Sdc.hh
index 82e4aac7..ac36b894 100644
--- a/include/sta/Sdc.hh
+++ b/include/sta/Sdc.hh
@@ -1034,6 +1034,7 @@ protected:
   void deleteMatchingExceptions(ExceptionPath *exception);
   void findMatchingExceptions(ExceptionPath *exception,
 			      ExceptionPathSet &matches);
+  void checkForThruHpins(ExceptionPath *exception);
   void findMatchingExceptionsFirstFrom(ExceptionPath *exception,
 				       ExceptionPathSet &matches);
   void findMatchingExceptionsFirstThru(ExceptionPath *exception,
@@ -1334,6 +1335,7 @@ protected:
   PinSet disabled_clk_gating_checks_pin_;
   ExceptionPathSet exceptions_;
 
+  bool have_thru_hpin_exceptions_;
   // First pin/clock/instance/net/edge exception point to exception set map.
   PinExceptionsMap *first_from_pin_exceptions_;
   ClockExceptionsMap *first_from_clk_exceptions_;
diff --git a/sdc/Sdc.cc b/sdc/Sdc.cc
index d196d570..7dc4c429 100644
--- a/sdc/Sdc.cc
+++ b/sdc/Sdc.cc
@@ -96,6 +96,7 @@ Sdc::Sdc(StaState *sta) :
   port_cap_map_(nullptr),
   net_wire_cap_map_(nullptr),
   drvr_pin_wire_cap_map_(nullptr),
+  have_thru_hpin_exceptions_(false),
   first_from_pin_exceptions_(nullptr),
   first_from_clk_exceptions_(nullptr),
   first_from_inst_exceptions_(nullptr),
@@ -4717,6 +4718,21 @@ Sdc::recordException(ExceptionPath *exception)
   exceptions_.insert(exception);
   recordMergeHashes(exception);
   recordExceptionFirstPts(exception);
+  checkForThruHpins(exception);
+}
+
+void
+Sdc::checkForThruHpins(ExceptionPath *exception)
+{
+  ExceptionThruSeq *thrus = exception->thrus();
+  if (thrus) {
+    for (ExceptionThru *thru : *thrus) {
+      if (thru->edges()) {
+        have_thru_hpin_exceptions_ = true;
+        break;
+      }
+    }
+  }
 }
 
 void
@@ -5016,6 +5032,7 @@ Sdc::deleteExceptions()
 
   deleteExceptionPtHashMapSets(exception_merge_hash_);
   exception_merge_hash_.clear();
+  have_thru_hpin_exceptions_ = false;
 }
 
 void
@@ -5954,19 +5971,21 @@ Sdc::setUseDefaultArrivalClock(bool enable)
 void
 Sdc::connectPinAfter(Pin *pin)
 {
-  PinSet *drvrs = network_->drivers(pin);
-  ExceptionPathSet::Iterator except_iter(exceptions_);
-  while (except_iter.hasNext()) {
-    ExceptionPath *exception = except_iter.next();
-    ExceptionPt *first_pt = exception->firstPt();
-    ExceptionThruSeq::Iterator thru_iter(exception->thrus());
-    while (thru_iter.hasNext()) {
-      ExceptionThru *thru = thru_iter.next();
-      if (thru->edges()) {
-	thru->connectPinAfter(drvrs, network_);
-	if (first_pt == thru)
-	  recordExceptionEdges(exception, thru->edges(),
-			       first_thru_edge_exceptions_);
+  if (have_thru_hpin_exceptions_) {
+    PinSet *drvrs = network_->drivers(pin);
+    ExceptionPathSet::Iterator except_iter(exceptions_);
+    while (except_iter.hasNext()) {
+      ExceptionPath *exception = except_iter.next();
+      ExceptionPt *first_pt = exception->firstPt();
+      ExceptionThruSeq::Iterator thru_iter(exception->thrus());
+      while (thru_iter.hasNext()) {
+        ExceptionThru *thru = thru_iter.next();
+        if (thru->edges()) {
+          thru->connectPinAfter(drvrs, network_);
+          if (first_pt == thru)
+            recordExceptionEdges(exception, thru->edges(),
+                                 first_thru_edge_exceptions_);
+        }
       }
     }
   }
@@ -5975,18 +5994,20 @@ Sdc::connectPinAfter(Pin *pin)
 void
 Sdc::disconnectPinBefore(Pin *pin)
 {
-  ExceptionPathSet::Iterator except_iter(exceptions_);
-  while (except_iter.hasNext()) {
-    ExceptionPath *exception = except_iter.next();
-    ExceptionPt *first_pt = exception->firstPt();
-    ExceptionThruSeq::Iterator thru_iter(exception->thrus());
-    while (thru_iter.hasNext()) {
-      ExceptionThru *thru = thru_iter.next();
-      if (thru->edges()) {
-	thru->disconnectPinBefore(pin, network_);
-	if (thru == first_pt)
-	  recordExceptionEdges(exception, thru->edges(),
-			       first_thru_edge_exceptions_);
+  if (have_thru_hpin_exceptions_) {
+    ExceptionPathSet::Iterator except_iter(exceptions_);
+    while (except_iter.hasNext()) {
+      ExceptionPath *exception = except_iter.next();
+      ExceptionPt *first_pt = exception->firstPt();
+      ExceptionThruSeq::Iterator thru_iter(exception->thrus());
+      while (thru_iter.hasNext()) {
+        ExceptionThru *thru = thru_iter.next();
+        if (thru->edges()) {
+          thru->disconnectPinBefore(pin, network_);
+          if (thru == first_pt)
+            recordExceptionEdges(exception, thru->edges(),
+                                 first_thru_edge_exceptions_);
+        }
       }
     }
   }
diff --git a/search/Sim.cc b/search/Sim.cc
index 3a1d6fa8..21fe0bf1 100644
--- a/search/Sim.cc
+++ b/search/Sim.cc
@@ -688,9 +688,8 @@ Sim::deletePinBefore(Pin *pin)
 void
 Sim::connectPinAfter(Pin *pin)
 {
-  // Incrementally update const_func_pins_.
-  recordConstPinFunc(pin);
   if (incremental_) {
+    recordConstPinFunc(pin);
     if (network_->isLoad(pin))
       invalid_load_pins_.insert(pin);
     if (network_->isDriver(pin))