[vpr][source][route] don't get prev edge is the node type is of the type source

Author: amin1377

vpr/src/route/connection_router.cpp

@@ -372,7 +372,7 @@ void ConnectionRouter<Heap>::timing_driven_expand_cheapest(t_heap* cheapest,
         VTR_LOGV_DEBUG(router_debug_, "    Better cost to %d\n", inode);
         VTR_LOGV_DEBUG(router_debug_, "    New total cost: %g\n", new_total_cost);
         VTR_LOGV_DEBUG(router_debug_, "    New back cost: %g\n", new_back_cost);
-        VTR_LOGV_DEBUG(router_debug_, "      Setting path costs for associated node %d (from %d edge %zu)\n",
+        VTR_LOGV_DEBUG(router_debug_ && (rr_nodes_.node_type(RRNodeId(cheapest->index) != t_rr_type::SOURCE)), "      Setting path costs for associated node %d (from %d edge %zu)\n",
                        cheapest->index,
                        static_cast<size_t>(rr_graph_->edge_src_node(cheapest->prev_edge())),
                        static_cast<size_t>(cheapest->prev_edge()));