1. Added physical-only cell instances in the top module to match the behavior b/w flat and hier flows.

2. Removed the temporary HOLD_SLACK_MARGIN as it is no longer needed.

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

Author: jhkim-pii

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.
@@ -8343,6 +8343,7 @@ 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/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/dbModule.cpp

@@ -201,7 +201,7 @@ void dbModule::addInst(dbInst* inst)
   _dbInst* _inst = (_dbInst*) inst;
   _dbBlock* block = (_dbBlock*) module->getOwner();
 
-  if (_inst->_flags._physical_only) {
+  if (isTop() == false && _inst->_flags._physical_only) {
     _inst->getLogger()->error(
         utl::ODB,
         297,
@@ -620,6 +620,16 @@ bool dbModule::canSwapWith(dbModule* new_module) const
   return true;
 }
 
+bool dbModule::isTop() const
+{
+  const _dbModule* obj = reinterpret_cast<const _dbModule*>(this);
+  const dbBlock* block = static_cast<dbBlock*>(obj->getOwner());
+  if (block == nullptr) {
+    return false;
+  }
+  return (block->getTopModule() == this);
+}
+
 // Do a "deep" copy of old_module based on its instance context into new_module.
 // All ports, instances, mod nets and parent/child IO will be copied.
 // Connections that span multiple modules needs to be done outside this API.

test/orfs/mock-array/BUILD

@@ -141,11 +141,6 @@ VARIANTS = [
         "IO_PLACER_H": "M4 M6",
         "DETAILED_ROUTE_END_ITERATION": "6",
         "OPENROAD_HIERARCHICAL": "1" if variant == "base" else "0",
-        # FIXME HOLD_SLACK_MARGIN should be removed after CTS engine improvement.
-        # - There are many hold violations due to large clock skew.
-        # - It leads to max buffer count limit error.
-        # - To avoid the error, large hold slack margin is temporarily set.
-        "HOLD_SLACK_MARGIN": "-30",
     },
     macros = ["Element_generate_abstract"],
     sources = {