doxygen comment for alloc_and_load_rr_node_indices

Author: soheilshahrouz

vpr/src/route/rr_graph2.cpp

@@ -1439,17 +1439,13 @@ static void add_classes_spatial_lookup(RRGraphBuilder& rr_graph_builder,
     }
 }
 
-/* As the rr_indices builders modify a local copy of indices, use the local copy in the builder */
 void alloc_and_load_rr_node_indices(RRGraphBuilder& rr_graph_builder,
                                     const t_chan_width& nodes_per_chan,
                                     const DeviceGrid& grid,
                                     int* index,
                                     const t_chan_details& chan_details_x,
                                     const t_chan_details& chan_details_y,
                                     bool is_flat) {
-    /* Allocates and loads all the structures needed for fast lookups of the
-     * index of an rr_node. rr_node_indices is a matrix containing the index
-     * of the *first* rr_node at a given (i,j) location. */
 
     /* Alloc the lookup table */
     for (e_rr_type rr_type : RR_TYPES) {

vpr/src/route/rr_graph2.h

@@ -14,6 +14,12 @@
 
 /******************* Subroutines exported by rr_graph2.c *********************/
 
+/**
+ * @brief Allocates and populates data structures for efficient rr_node index lookups.
+ *
+ * This function sets up the `rr_node_indices` structure, which maps a physical location
+ * and type to the index of the first corresponding rr_node.
+ */
 void alloc_and_load_rr_node_indices(RRGraphBuilder& rr_graph_builder,
                                     const t_chan_width& nodes_per_chan,
                                     const DeviceGrid& grid,
@@ -22,6 +28,7 @@ void alloc_and_load_rr_node_indices(RRGraphBuilder& rr_graph_builder,
                                     const t_chan_details& chan_details_y,
                                     bool is_flat);
 
+
 /**
  * @brief allocates extra nodes within the RR graph to support 3D custom switch blocks for multi-die FPGAs
  *