fix valgrind issue (using uninitialized variable)

Author: soheilshahrouz

vpr/src/place/net_cost_handler.cpp

@@ -1725,7 +1725,7 @@ double NetCostHandler::get_total_wirelength_estimate() const {
     return estimated_wirelength;
 }
 
-double NetCostHandler::estimate_routing_chan_util() {
+double NetCostHandler::estimate_routing_chan_util(bool compute_congestion_cost/* = true*/) {
     const auto& cluster_ctx = g_vpr_ctx.clustering();
     const DeviceContext& device_ctx = g_vpr_ctx.device();
 
@@ -1850,10 +1850,12 @@ double NetCostHandler::estimate_routing_chan_util() {
 
     double cong_cost = 0.;
     // Compute congestion cost using recomputed bounding boxes and channel utilization map
-    for (ClusterNetId net_id : cluster_ctx.clb_nlist.nets()) {
-        if (!cluster_ctx.clb_nlist.net_is_ignored(net_id)) {
-            net_cong_cost_[net_id] = get_net_cube_cong_cost_(net_id, /*use_ts=*/false);
-            cong_cost += net_cong_cost_[net_id];
+    if (compute_congestion_cost) {
+        for (ClusterNetId net_id : cluster_ctx.clb_nlist.nets()) {
+            if (!cluster_ctx.clb_nlist.net_is_ignored(net_id)) {
+                net_cong_cost_[net_id] = get_net_cube_cong_cost_(net_id, /*use_ts=*/false);
+                cong_cost += net_cong_cost_[net_id];
+            }
         }
     }
 

vpr/src/place/net_cost_handler.h

@@ -143,7 +143,7 @@ class NetCostHandler {
      *
      * @return Total congestion cost.
      */
-    double estimate_routing_chan_util();
+    double estimate_routing_chan_util(bool compute_congestion_cost = true);
 
     std::pair<const vtr::NdMatrix<double, 3>&, const vtr::NdMatrix<double, 3>&> get_chanxy_util() const;
 

vpr/src/route/route_utilization.cpp

@@ -24,7 +24,7 @@ std::pair<vtr::NdMatrix<double, 3>, vtr::NdMatrix<double, 3>> RoutingChanUtilEst
         net_cost_handler_->comp_bb_cong_cost(e_cost_methods::NORMAL);
 
         // Estimate routing channel utilization using
-        net_cost_handler_->estimate_routing_chan_util();
+        net_cost_handler_->estimate_routing_chan_util(/*compute_congestion_cost=*/false);
 
         return net_cost_handler_->get_chanxy_util();
     } else {