add doxygen comment for RoutingChanUtilEstimator

Author: soheilshahrouz

vpr/src/route/route_utilization.cpp

@@ -85,7 +85,7 @@ vtr::Matrix<float> calculate_routing_avail(e_rr_type rr_type) {
     // Calculate the number of available resources in each x/y channel
     VTR_ASSERT(rr_type == e_rr_type::CHANX || rr_type == e_rr_type::CHANY);
 
-    auto& device_ctx = g_vpr_ctx.device();
+    const auto& device_ctx = g_vpr_ctx.device();
     const auto& rr_graph = device_ctx.rr_graph;
 
     vtr::Matrix<float> avail({{device_ctx.grid.width(), device_ctx.grid.height()}}, 0.);

vpr/src/route/route_utilization.h

@@ -6,6 +6,12 @@
 #include "net_cost_handler.h"
 #include "placer_state.h"
 
+/**
+ * @class RoutingChanUtilEstimator
+ * @brief This class computes the net bounding boxes and estimates the routing channel utilization
+ * for each CHANX/CHANY channel by smearing the estimated wirelength for each net across all channels
+ * within its bounding box.
+ */
 class RoutingChanUtilEstimator {
   public:
     RoutingChanUtilEstimator(const BlkLocRegistry& blk_loc_registry, bool cube_bb);
@@ -16,7 +22,6 @@ class RoutingChanUtilEstimator {
     std::unique_ptr<PlacerState> placer_state_;
     std::unique_ptr<NetCostHandler> net_cost_handler_;
     t_placer_opts placer_opts_;
-
 };
 
 vtr::Matrix<float> calculate_routing_avail(e_rr_type rr_type);