add doxygen comments

Author: soheilshahrouz

vpr/src/base/stats.h

@@ -21,6 +21,16 @@ void routing_stats(const Netlist<>& net_list,
                    int wire_to_ipin_switch,
                    bool is_flat);
 
+/**
+ * @brief Calculates the routing channel width at each grid location.
+ *
+ * Iterates through all RR nodes and counts how many wires pass through each (x, y) location
+ * for both horizontal (CHANX) and vertical (CHANY) channels.
+ *
+ * @return A pair of 3D matrices:
+ *         - First: CHANX width per [layer][x][y]
+ *         - Second: CHANY width per [layer][x][y]
+ */
 std::pair<vtr::NdMatrix<int, 3>, vtr::NdMatrix<int, 3>> calculate_channel_width();
 
 void print_wirelen_prob_dist(bool is_flat);

vpr/src/base/vpr_context.h

@@ -559,7 +559,9 @@ struct RoutingContext : public Context {
     /** Is flat routing enabled? */
     bool is_flat;
 
+    /// @brief Post-placement estimate of CHANX routing utilization per (layer, x, y) location.
     vtr::NdMatrix<double, 3> chanx_util;
+    /// @brief Post-placement estimate of CHANY routing utilization per (layer, x, y) location.
     vtr::NdMatrix<double, 3> chany_util;
 };
 

vpr/src/route/route_common.cpp

@@ -69,6 +69,19 @@ static vtr::vector<ParentNetId, uint8_t> load_is_clock_net(const Netlist<>& net_
 
 static bool classes_in_same_block(ParentBlockId blk_id, int first_class_ptc_num, int second_class_ptc_num, bool is_flat);
 
+/**
+ * @brief Computes the initial `acc_cost` for the given RR node by checking
+ *        if the node is of type CHANX/CHANY and goes through a possibly congested
+ *        routing channel.
+ * @param node_id    The RR node whose initial acc_cost is to be computed.
+ * @param route_opts Contains channel utilization threshold and weighting factor
+ *                   used to increase initial 'acc_cost' for nodes going through
+ *                   congested channels.
+ * @return Initial `acc_cost` for the given RR node.
+ */
+static float comp_initial_acc_cost(RRNodeId node_id,
+                                   const t_router_opts& route_opts);
+
 /************************** Subroutine definitions ***************************/
 
 void save_routing(vtr::vector<ParentNetId, vtr::optional<RouteTree>>& best_routing,
@@ -414,7 +427,8 @@ void alloc_and_load_rr_node_route_structs(const t_router_opts& router_opts) {
     }
 }
 
-static float comp_initial_acc_cost(RRNodeId node_id, const t_router_opts& route_opts) {
+static float comp_initial_acc_cost(RRNodeId node_id,
+                                   const t_router_opts& route_opts) {
     const auto& route_ctx = g_vpr_ctx.routing();
     const auto& rr_graph = g_vpr_ctx.device().rr_graph;
 

vpr/src/route/router_lookahead_extended_map.cpp

@@ -427,9 +427,6 @@ void ExtendedMapLookahead::compute(const std::vector<t_segment_inf>& segment_inf
 
     vtr::ScopedStartFinishTimer timer("Computing connection box lookahead map");
 
-    // Initialize rr_node_route_inf if not already
-    //    alloc_and_load_rr_node_route_structs();
-
     size_t num_segments = segment_inf.size();
     std::vector<SampleRegion> sample_regions = find_sample_regions(num_segments);