[core] fixed a bug where unused last-level of clock spines are not disabled

openfpga/src/annotation/openfpga_annotate_routing.cpp

@@ -90,7 +90,7 @@ vtr::vector<RRNodeId, ClusterNetId> annotate_rr_node_global_net(
         rr_graph.node_lookup().find_nodes_at_all_sides(
           layer, blk_loc.loc.x, blk_loc.loc.y, rr_pin_type, node_pin_num);
       for (RRNodeId curr_rr_node : curr_rr_nodes) {
-        VTR_LOGV(verbose, "on '%s' pin '%d'\n",
+        VTR_LOGV(verbose, "Annotate global net '%s' on '%s' pin '%d'\n",
                  cluster_nlist.net_name(net_id).c_str(), phy_tile->name,
                  node_pin_num);
         rr_node_nets[curr_rr_node] = net_id;

openfpga/src/annotation/route_clock_rr_graph.cpp

@@ -317,6 +317,15 @@ static int rec_expand_and_route_clock_spine(
   if (curr_tap_usage) {
     curr_spine_usage = true;
   }
+  /* If no taps are routed, this spine is not used. Early exit */
+  if (!curr_tap_usage && clk_ntwk.is_last_level(curr_spine)) {
+    spine_usage = false;
+    VTR_LOGV(verbose,
+             "Disable last-level spine '%s' as "
+             "none of the taps are not used\n",
+             clk_ntwk.spine_name(curr_spine).c_str());
+    return CMD_EXEC_SUCCESS;
+  }
 
   std::vector<vtr::Point<int>> spine_coords =
     clk_ntwk.spine_coordinates(curr_spine);