weigh congestion cost along x/y axis with the length of bb along that dimension

Author: soheilshahrouz

vpr/src/place/net_cost_handler.cpp

@@ -1423,14 +1423,19 @@ double NetCostHandler::get_net_cube_bb_cost_(ClusterNetId net_id, bool use_ts) {
 }
 
 double NetCostHandler::get_net_cube_cong_cost_(ClusterNetId net_id, bool use_ts) {
-    auto [x_chan_cong, y_chan_cong] = use_ts ? ts_avg_chann_util_new_[net_id] : avg_chann_util_[net_id];
+    const auto [x_chan_util, y_chan_util] = use_ts ? ts_avg_chann_util_new_[net_id] : avg_chann_util_[net_id];
+
+    const t_bb& bb = use_ts ? ts_bb_coord_new_[net_id] : bb_coords_[net_id];
+
+    int distance_x = bb.xmax - bb.xmin + 1;
+    int distance_y = bb.ymax - bb.ymin + 1;
 
     const float threshold = placer_opts_.congestion_chan_util_threshold;
 
-    x_chan_cong = (x_chan_cong < threshold) ? 0.0f : x_chan_cong - threshold;
-    y_chan_cong = (y_chan_cong < threshold) ? 0.0f : y_chan_cong - threshold;
+    float x_chan_cong = (x_chan_util < threshold) ? 0.0f : x_chan_util - threshold;
+    float y_chan_cong = (y_chan_util < threshold) ? 0.0f : y_chan_util - threshold;
 
-    return x_chan_cong + y_chan_cong;
+    return (distance_x * x_chan_cong) + (distance_y * y_chan_cong);
 }
 
 double NetCostHandler::get_net_per_layer_bb_cost_(ClusterNetId net_id, bool use_ts) {