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Author: soheilshahrouz

libs/libvtrutil/src/vtr_ndmatrix.h

@@ -322,7 +322,7 @@ class NdMatrixBase {
 
     ///@brief Returns the size of the matrix (number of elements) calculated from the current dimensions
     size_t calc_size() const {
-        ///@brief Size is the product of all dimension sizes
+        // Size is the product of all dimension sizes
         size_t cnt = dim_size(0);
         for (size_t idim = 1; idim < ndims(); ++idim) {
             cnt *= dim_size(idim);

vpr/src/route/rr_graph_generation/build_scatter_gathers.cpp

@@ -102,13 +102,18 @@ static std::vector<t_sg_candidate> find_candidate_wires(const std::vector<t_chan
             int first_type_wire = wire_type_sizes.at(wire_type).start;
             int last_type_wire = first_type_wire + num_type_wires - 1;
 
+            // Walk through each wire segment of specified type and check whether it matches one
+            // of the specified switchpoints.
+            // Note that we walk through the points in order, this ensures that returned switchpoints
+            // match the order specified in the architecture, which we assume is a priority order specified
+            // by the architect.
             for (int valid_switchpoint : wire_switchpoints.switchpoints) {
                 for (int iwire = first_type_wire; iwire <= last_type_wire; iwire++) {
                     Direction seg_direction = chan_details[iwire].direction();
 
-                    /* unidirectional wires going in the decreasing direction can have an outgoing edge
-                     * only from the top or right switch block sides, and an incoming edge only if they are
-                     * at the left or bottom sides (analogous for wires going in INC direction) */
+                    // unidirectional wires going in the decreasing direction can have an outgoing edge
+                    // only from the top or right switch block sides, and an incoming edge only if they are
+                    // at the left or bottom sides (analogous for wires going in INC direction) */
                     if (chan_side == TOP || chan_side == RIGHT) {
                         if (seg_direction == Direction::DEC && is_dest) {
                             continue;

vpr/src/route/rr_graph_generation/build_scatter_gathers.h

@@ -21,6 +21,8 @@ struct t_sg_candidate {
 };
 
 /// Represents a scatter/gather bottleneck connection between two locations.
+/// This data structure is used in RR graph generation to model a node that is
+/// driven by wires at a gather location and drives wires at a scatter location.
 struct t_bottleneck_link {
     t_physical_tile_loc gather_loc;                         ///< Source switchblock location.
     t_physical_tile_loc scatter_loc;                        ///< Destination switchblock location.
@@ -44,7 +46,7 @@ struct t_bottleneck_link {
  * @param chan_details_y Channel details for vertical routing channels.
  * @param nodes_per_chan Channel width data.
  * @param interdie_3d_links Output: matrix storing inter-die (3D) bottleneck links.
- * @return Vector of intra-die bottleneck links.
+ * @return Vector of non-3d bottleneck links.
  */
 std::vector<t_bottleneck_link> alloc_and_load_scatter_gather_connections(const std::vector<t_scatter_gather_pattern>& scatter_gather_patterns,
                                                                          const std::vector<bool>& inter_cluster_rr,

vpr/src/route/rr_graph_generation/build_switchblocks.cpp

@@ -323,9 +323,9 @@ static void get_switchpoint_wires(const t_chan_seg_details* chan_details,
             for (int iwire = first_type_wire; iwire <= last_type_wire; iwire++) {
                 Direction seg_direction = chan_details[iwire].direction();
 
-                /* unidirectional wires going in the decreasing direction can have an outgoing edge
-                 * only from the top or right switch block sides, and an incoming edge only if they are
-                 * at the left or bottom sides (analogous for wires going in INC direction) */
+                // unidirectional wires going in the decreasing direction can have an outgoing edge
+                // only from the top or right switch block sides, and an incoming edge only if they are
+                // at the left or bottom sides (analogous for wires going in INC direction)
                 if (side == TOP || side == RIGHT) {
                     if (seg_direction == Direction::DEC && is_dest) {
                         continue;