add invalid id checks before accessing data structures indexed by cluster id

Author: KA7E

vpr/src/base/clustered_netlist_utils.cpp

@@ -48,7 +48,9 @@ void ClusterAtomsLookup::init_lookup() {
     for (auto atom_blk_id : atom_ctx.nlist.blocks()) {
         ClusterBlockId clb_index = atom_ctx.lookup.atom_clb(atom_blk_id);
 
-        cluster_atoms[clb_index].push_back(atom_blk_id);
+        if (clb_index != ClusterBlockId::INVALID()) {
+            cluster_atoms[clb_index].push_back(atom_blk_id);
+        }
     }
 }
 

vpr/src/pack/cluster_util.cpp

@@ -3686,6 +3686,8 @@ void init_clb_atoms_lookup(vtr::vector<ClusterBlockId, std::unordered_set<AtomBl
     for (auto atom_blk_id : atom_ctx.nlist.blocks()) {
         ClusterBlockId clb_index = atom_ctx.lookup.atom_clb(atom_blk_id);
 
-        atoms_lookup[clb_index].insert(atom_blk_id);
+        if (clb_index != ClusterBlockId::INVALID()) {
+            atoms_lookup[clb_index].insert(atom_blk_id);
+        }
     }
-}
+}