start fixing the bug in thru channels

vpr/src/tileable_rr_graph/rr_graph_builder_utils.cpp

@@ -172,7 +172,21 @@ size_t get_grid_num_classes(const t_grid_tile& cur_grid,
  *  When height_offset == height - 1, it means that the grid is at the top side of this multi-width and multi-height block
  ***********************************************************************/
 bool is_chanx_exist(const DeviceGrid& grids,
-                    const vtr::Point<size_t>& chanx_coord) {
+                    const vtr::Point<size_t>& chanx_coord,
+                    const bool& through_channel) {
+
+  if ((1 > chanx_coord.x()) || (chanx_coord.x() > grids.width() - 2)) {
+    return false;
+  }
+
+  if (chanx_coord.y() > grids.height() - 2) {
+    return false;
+  }
+
+  if (true == through_channel) {
+    return true;
+  }
+
   return (grids[chanx_coord.x()][chanx_coord.y()].height_offset == grids[chanx_coord.x()][chanx_coord.y()].type->height - 1);
 }
 
@@ -192,9 +206,26 @@ bool is_chanx_exist(const DeviceGrid& grids,
  *  If the CHANY is in the middle of a multi-width and multi-height grid
  *  it should locate at a grid whose width_offset is lower than the its width defined in physical_tile
  *  When height_offset == height - 1, it means that the grid is at the top side of this multi-width and multi-height block
+ *
+ *  If through channel is allowed, the chany will always exists
+ *  unless it falls out of the grid array
  ***********************************************************************/
 bool is_chany_exist(const DeviceGrid& grids,
-                    const vtr::Point<size_t>& chany_coord) {
+                    const vtr::Point<size_t>& chany_coord,
+                    const bool& through_channel) {
+
+  if (chany_coord.x() > grids.width() - 2) {
+    return false;
+  }
+
+  if ((1 > chany_coord.y()) || (chany_coord.y() > grids.height() - 2)) {
+    return false;
+  }
+
+  if (true == through_channel) {
+    return true;
+  }
+
   return (grids[chany_coord.x()][chany_coord.y()].width_offset == grids[chany_coord.x()][chany_coord.y()].type->width - 1);
 }
 

vpr/src/tileable_rr_graph/rr_graph_builder_utils.h

@@ -40,10 +40,12 @@ size_t get_grid_num_classes(const t_grid_tile& cur_grid,
                             const e_pin_type& pin_type);
 
 bool is_chanx_exist(const DeviceGrid& grids,
-                    const vtr::Point<size_t>& chanx_coord);
+                    const vtr::Point<size_t>& chanx_coord,
+                    const bool& through_channel=false);
 
 bool is_chany_exist(const DeviceGrid& grids,
-                    const vtr::Point<size_t>& chany_coord);
+                    const vtr::Point<size_t>& chany_coord,
+                    const bool& through_channel=false);
 
 bool is_chanx_right_to_multi_height_grid(const DeviceGrid& grids,
                                          const vtr::Point<size_t>& chanx_coord,

vpr/src/tileable_rr_graph/tileable_rr_graph_node_builder.cpp

@@ -186,7 +186,8 @@ size_t estimate_num_chanx_rr_nodes(const DeviceGrid& grids,
       vtr::Point<size_t> chanx_coord(ix, iy);
 
       /* Bypass if the routing channel does not exist when through channels are not allowed */
-      if (false == is_chanx_exist(grids, chanx_coord)) {
+      if ( (false == through_channel)
+        && (false == is_chanx_exist(grids, chanx_coord))) {
         continue;
       }
 
@@ -237,11 +238,13 @@ size_t estimate_num_chany_rr_nodes(const DeviceGrid& grids,
     for (size_t iy = 1; iy < grids.height() - 1; ++iy) { 
       vtr::Point<size_t> chany_coord(ix, iy);
 
-      /* Bypass if the routing channel does not exist when through channels are not allowed */
+      /* Bypass if the routing channel does not exist when through channel are not allowed */
-      if (false == is_chany_exist(grids, chany_coord)) {
+      if ( (false == through_channel)
+        && (false == is_chany_exist(grids, chany_coord))) {
         continue;
       }
 
+
       bool force_start = false;
       bool force_end = false;
 
@@ -922,7 +925,9 @@ void load_chany_rr_nodes_basic_info(RRGraph& rr_graph,
 
       ChanNodeDetails chany_details = build_unidir_chan_node_details(chan_width, grids.height() - 2,
                                                                      force_start, force_end, segment_infs); 
-      /* Force node_ids from the previous chanx */
+      /* Force node_ids from the previous chany
+       * This will not be applied when the routing channel is cut off (force to start)
+       */
       if (0 < track_node_ids.size()) {
         /* Rotate should be done based on a typical case of routing tracks.
          * Tracks on the borders are not regularly started and ended,