Merge pull request #8241 from The-OpenROAD-Project-staging/secure-fix-cts-del-modnet

cts: Deleted dangling dbModNet for top-level clock port.

Author: maliberty

src/cts/include/cts/TritonCTS.h

@@ -34,6 +34,7 @@ class Unit;
 class LibertyCell;
 class Vertex;
 class Graph;
+class Pin;
 }  // namespace sta
 
 namespace stt {
@@ -114,6 +115,7 @@ class TritonCTS
   // db functions
   bool masterExists(const std::string& master) const;
   void populateTritonCTS();
+  void destroyClockModNet(sta::Pin* pin_driver);
   void writeClockNetsToDb(TreeBuilder* builder,
                           std::set<odb::dbNet*>& clkLeafNets);
   void writeClockNDRsToDb(TreeBuilder* builder);

src/cts/src/TritonCTS.cpp

@@ -1392,6 +1392,18 @@ void TritonCTS::computeITermPosition(odb::dbITerm* term, int& x, int& y) const
   }
 };
 
+void TritonCTS::destroyClockModNet(sta::Pin* pin_driver)
+{
+  if (pin_driver == nullptr || network_->hasHierarchy() == false) {
+    return;
+  }
+
+  odb::dbModNet* mod_net = network_->hierNet(pin_driver);
+  if (mod_net) {
+    odb::dbModNet::destroy(mod_net);
+  }
+}
+
 void TritonCTS::writeClockNetsToDb(TreeBuilder* builder,
                                    std::set<odb::dbNet*>& clkLeafNets)
 {
@@ -1405,6 +1417,12 @@ void TritonCTS::writeClockNetsToDb(TreeBuilder* builder,
 
   disconnectAllSinksFromNet(topClockNet);
 
+  // If exists, remove the dangling dbModNet related to the topClockNet because
+  // topClockNet has no load pin now.
+  // After CTS, the driver pin will drive only a few of root clock buffers.
+  // So the hierarchical net (dbModNet) is not needed any more.
+  destroyClockModNet(pin_driver);
+
   // re-connect top buffer that separates macros from registers
   if (builder->getTreeType() == TreeType::RegisterTree) {
     odb::dbInst* topRegBuffer

src/dbSta/src/dbNetwork.cc

@@ -2592,7 +2592,7 @@ void dbNetwork::disconnectPin(Pin* pin, Net* net)
       iterm->disconnectDbNet();
     }
     if (mod_net) {
-      iterm->disconnectModNet();
+      iterm->disconnectDbModNet();
     }
   } else if (bterm) {
     if (db_net) {

src/odb/include/odb/db.h

@@ -617,7 +617,7 @@ class dbBlock : public dbObject
   ///
   /// Returns the top module of this block.
   ///
-  dbModule* getTopModule();
+  dbModule* getTopModule() const;
 
   ///
   /// Get the child blocks of this block.
@@ -2947,8 +2947,8 @@ class dbInst : public dbObject
 
   ///
   /// Create a new instance.
-  /// If physical_only is true the instance can't bee added to a dbModule.
-  /// If false, it will be added to the top module.
+  /// If physical_only is true, the instance can only be added to a top module.
+  /// If false, it will be added to the parent module.
   /// Returns nullptr if an instance with this name already exists.
   /// Returns nullptr if the master is not FROZEN.
   /// If dbmodule is non null the dbInst is added to that module.
@@ -3202,7 +3202,7 @@ class dbITerm : public dbObject
   /// Disconnect just the mod net
   ///
 
-  void disconnectModNet();
+  void disconnectDbModNet();
 
   ///
   /// Get the average of the centers for the iterm shapes
@@ -8293,6 +8293,7 @@ class dbModNet : public dbObject
   unsigned connectionCount();
   const char* getName() const;
   void rename(const char* new_name);
+  void disconnectAllTerms();
 
   static dbModNet* getModNet(dbBlock* block, uint id);
   static dbModNet* create(dbModule* parentModule, const char* base_name);
@@ -8343,6 +8344,7 @@ class dbModule : public dbObject
 
   const dbModBTerm* getHeadDbModBTerm() const;
   bool canSwapWith(dbModule* new_module) const;
+  bool isTop() const;
 
   static dbModule* create(dbBlock* block, const char* name);
 

src/odb/src/db/dbBlock.cpp

@@ -1581,7 +1581,7 @@ dbInst* dbBlock::getParentInst()
   return (dbInst*) parent_inst;
 }
 
-dbModule* dbBlock::getTopModule()
+dbModule* dbBlock::getTopModule() const
 {
   _dbBlock* block = (_dbBlock*) this;
   return (dbModule*) block->_module_tbl->getPtr(block->_top_module);

src/odb/src/db/dbITerm.cpp

@@ -405,7 +405,7 @@ void dbITerm::connect(dbModNet* mod_net)
   // accidentally blow away prior flat net connections)
 
   if (iterm->_mnet != 0) {
-    disconnectModNet();
+    disconnectDbModNet();
   }
 
   iterm->_mnet = _mod_net->getId();
@@ -625,7 +625,7 @@ void dbITerm::disconnectDbNet()
 //
 // Disconnect the mod net and allow journaling
 //
-void dbITerm::disconnectModNet()
+void dbITerm::disconnectDbModNet()
 {
   _dbITerm* iterm = (_dbITerm*) this;
   _dbBlock* block = (_dbBlock*) iterm->getOwner();

src/odb/src/db/dbInst.cpp

@@ -1322,7 +1322,10 @@ dbInst* dbInst::create(dbBlock* block_,
   block->add_rect(box->_shape._rect);
 
   inst->_flags._physical_only = physical_only;
-  if (!physical_only) {
+
+  // Add the new instance to the parent module.
+  bool parent_is_top = parent_module == nullptr || parent_module->isTop();
+  if (physical_only == false || parent_is_top) {
     if (parent_module) {
       parent_module->addInst((dbInst*) inst);
     } else {

src/odb/src/db/dbJournal.cpp

@@ -784,7 +784,7 @@ void dbJournal::redo_disconnectObject()
       } else if (net_id != 0) {
         iterm->disconnectDbNet();
       } else if (mnet_id != 0) {
-        iterm->disconnectModNet();
+        iterm->disconnectDbModNet();
       }
       break;
     }
@@ -2082,7 +2082,7 @@ void dbJournal::undo_connectObject()
         iterm->disconnectDbNet();
       }
       if (mnet_id != 0) {
-        iterm->disconnectModNet();
+        iterm->disconnectDbModNet();
       }
       break;
     }

src/odb/src/db/dbModInst.cpp

@@ -587,7 +587,7 @@ dbModInst* dbModInst::swapMaster(dbModule* new_module)
       // iterm may be connected to another hierarchical instance
       dbModNet* other_mod_net = old_iterm->getModNet();
       if (other_mod_net != old_mod_net) {
-        old_iterm->disconnectModNet();
+        old_iterm->disconnectDbModNet();
         old_iterm->connect(old_mod_net);  // Reconnect old mod net for later use
         debugRDPrint1("  disconnected old iterm {} from other mod net {}",
                       old_iterm->getName(),

src/odb/src/db/dbModNet.cpp

@@ -178,6 +178,28 @@ void dbModNet::rename(const char* new_name)
   parent->_modnet_hash[new_name] = obj->getOID();
 }
 
+void dbModNet::disconnectAllTerms()
+{
+  // Disconnect all terminals.
+  // - The loops are structured this way to handle the modification of the dbSet
+  // during iteration.
+  while (!getITerms().empty()) {
+    getITerms().begin()->disconnectDbModNet();
+  }
+
+  while (!getBTerms().empty()) {
+    getBTerms().begin()->disconnectDbModNet();
+  }
+
+  while (!getModITerms().empty()) {
+    getModITerms().begin()->disconnect();
+  }
+
+  while (!getModBTerms().empty()) {
+    getModBTerms().begin()->disconnect();
+  }
+}
+
 dbModNet* dbModNet::getModNet(dbBlock* block, uint id)
 {
   _dbBlock* block_ = (_dbBlock*) block;
@@ -225,6 +247,8 @@ void dbModNet::destroy(dbModNet* mod_net)
   _dbBlock* block = (_dbBlock*) _modnet->getOwner();
   _dbModule* module = block->_module_tbl->getPtr(_modnet->_parent);
 
+  mod_net->disconnectAllTerms();
+
   // journalling
   if (block->_journal) {
     block->_journal->beginAction(dbJournal::DELETE_OBJECT);