Added dbNetwork::highestNetAbove(Net*) const override.

This is required to avoid a hang issue.

Signed-off-by: Jaehyun Kim <[email protected]>

Author: jhkim-pii

src/dbSta/include/db_sta/dbNetwork.hh

@@ -337,6 +337,11 @@ class dbNetwork : public ConcreteNetwork
 
   bool hasPort(const Net* net) const;
 
+  // Return the highest net above the given net.
+  // - If the net is a flat net, return it.
+  // - If the net is a hier net, return the modnet in the highest hierarchy.
+  Net* highestNetAbove(Net* net) const override;
+
   ////////////////////////////////////////////////////////////////
   // Edit functions
   Instance* makeInstance(LibertyCell* cell,

src/dbSta/src/dbNetwork.cc

@@ -5024,4 +5024,36 @@ bool dbNetwork::isPGSupply(dbNet* net) const
   return net->isSpecial() && net->getSigType().isSupply();
 }
 
+Net* dbNetwork::highestNetAbove(Net* net) const
+{
+  if (net == nullptr) {
+    return nullptr;
+  }
+
+  dbNet* dbnet;
+  dbModNet* modnet;
+  staToDb(net, dbnet, modnet);
+
+  if (dbnet) {
+    // If a flat net, return it.
+    // - We should not return the highest modnet related to the flat net.
+    // - Otherwise, it breaks estimate_parasitics function.
+    //   . est module uses flat nets for parasitic estimation
+    //   . It has (highestNetAbove(flat_net) != flat_net) comparison.
+    //   . If highestNetAbove(flat_net) returns the highest modnet, it
+    //     changes the estimate_parasitics behavior.
+    return net;
+  }
+
+  if (modnet) {
+    if (dbNet* related_dbnet = modnet->findRelatedNet()) {
+      if (dbModNet* highest_modnet = related_dbnet->findModNetInHighestHier()) {
+        return dbToSta(highest_modnet);  // Found the highest modnet
+      }
+    }
+  }
+
+  return net;
+}
+
 }  // namespace sta

src/dbSta/test/cpp/TestDbSta.cc

@@ -59,6 +59,41 @@ TEST_F(TestDbSta, TestIsConnected)
 
   bool_return = db_network_->isConnected(sta_net, sta_modnet);
   ASSERT_TRUE(bool_return);
+
+  // Check Network::highestNetAbove(Net* net)
+  dbNet* dbnet_out2 = block_->findNet("out2");
+  ASSERT_NE(dbnet_out2, nullptr);
+  Net* sta_dbnet_out2 = db_network_->dbToSta(dbnet_out2);
+  ASSERT_NE(sta_dbnet_out2, nullptr);
+  Net* sta_highest_net = db_network_->highestNetAbove(sta_dbnet_out2);
+  ASSERT_EQ(sta_highest_net, sta_dbnet_out2);
+
+  dbModNet* modnet_mod_out = block_->findModNet("sub_inst/mod_out");
+  ASSERT_NE(modnet_mod_out, nullptr);
+  Net* sta_modnet_mod_out = db_network_->dbToSta(modnet_mod_out);
+  ASSERT_NE(sta_modnet_mod_out, nullptr);
+  dbModNet* modnet_out2 = block_->findModNet("out2");
+  ASSERT_NE(modnet_out2, nullptr);
+  Net* sta_modnet_out2 = db_network_->dbToSta(modnet_out2);
+  ASSERT_NE(sta_modnet_out2, nullptr);
+  Net* sta_highest_modnet_out
+      = db_network_->highestNetAbove(sta_modnet_mod_out);
+  ASSERT_EQ(sta_highest_modnet_out, sta_modnet_out2);
+
+  // Check get_ports -of_object Net*
+  NetTermIterator* term_iter = db_network_->termIterator(sta_dbnet_out2);
+  while (term_iter->hasNext()) {
+    Term* term = term_iter->next();
+    Pin* pin = db_network_->pin(term);
+    Port* port = db_network_->port(pin);
+    ASSERT_EQ(db_network_->name(port), block_->findBTerm("out2")->getName());
+  }
+
+  // Check dbBTerm::getITerm()
+  dbBTerm* bterm_clk = block_->findBTerm("in1");
+  ASSERT_NE(bterm_clk, nullptr);
+  // There is no related dbITerm for a dbBTerm
+  ASSERT_EQ(bterm_clk->getITerm(), nullptr);
 }
 
 }  // namespace sta