Tried to minimize QoR impact 4

4. Disconnect first, and mergeNet

Signed-off-by: Jaehyun Kim <jhkim@precisioninno.com>

Author: jhkim-pii

src/rsz/src/UnbufferMove.cc

@@ -364,8 +364,8 @@ void UnbufferMove::removeBuffer(Instance* buffer)
   // Remove the unused buffer
   if (out_db_net == nullptr) {
     // jk: behavior change point1
-    // dbInst* dbinst_buffer = db_network_->staToDb(buffer);
-    // dbInst::destroy(dbinst_buffer);
+    dbInst* dbinst_buffer = db_network_->staToDb(buffer);
+    dbInst::destroy(dbinst_buffer);
     return;
   }
 
@@ -380,15 +380,15 @@ void UnbufferMove::removeBuffer(Instance* buffer)
   odb::dbModNet* removed_modnet = op_modnet;
   bool out_net_has_port = db_network_->hasPort(out_net);
   // jk: behavior change point2
-  // bool in_net_has_port = db_network_->hasPort(in_net);
-  // if (in_net_has_port == false && out_net_has_port == true) {
-  if (out_net_has_port == true) {
-    // output net has port, so it should survive
+  bool in_net_has_port = db_network_->hasPort(in_net);
+  if (in_net_has_port == false && out_net_has_port == true) {
+    // if (out_net_has_port == true) {
+    //  output net has port, so it should survive
     survivor = out_net;
     removed = in_net;
     // jk: behavior change point2
-    // survivor_modnet = op_modnet;
-    // removed_modnet = ip_modnet;
+    survivor_modnet = op_modnet;
+    removed_modnet = ip_modnet;
   }
 
   // Disconnect the buffer and handle the nets