Now direct connection builder checks the port name of destination subtile (#3320)

* [test] add new test case to validate direct connection from two identify source subtile to single destination subtile

* [core] now to_port name is also checked in building direction connection

* [core] typo

* [test] debug

* [test] update golden

* [core] code comments format

Author: tangxifan

vpr/src/route/rr_graph_generation/clb2clb_directs.cpp

@@ -62,6 +62,8 @@ std::vector<t_clb_to_clb_directs> alloc_and_load_clb_to_clb_directs(const std::v
         clb_to_clb_directs[i].to_clb_type = physical_tile;
 
         tile_port = find_tile_port_by_name(physical_tile, port_name);
+        // Cache the destination port name as the pin index is not enough to identify if the destination subtile is the one we want
+        clb_to_clb_directs[i].to_port = port_name;
 
         if (start_pin_index == UNDEFINED) {
             VTR_ASSERT(start_pin_index == end_pin_index);

vpr/src/route/rr_graph_generation/clb2clb_directs.h

@@ -17,6 +17,7 @@ struct t_clb_to_clb_directs {
     int from_clb_pin_start_index;
     int from_clb_pin_end_index;
     t_physical_tile_type_ptr to_clb_type;
+    std::string to_port;
     int to_clb_pin_start_index;
     int to_clb_pin_end_index;
     int switch_index; //The switch type used by this direct connection

vpr/src/route/rr_graph_generation/tileable_rr_graph/tileable_rr_graph_gsb.cpp

@@ -1763,7 +1763,7 @@ void build_direct_connections_for_one_gsb(const RRGraphView& rr_graph,
                     int to_subtile_cap = z + directs[i].sub_tile_offset;
                     /* If the destination subtile is out of range, there is no qualified IPINs */
                     if (to_subtile_cap < 0 || to_subtile_cap >= to_grid_type->capacity) {
-                      continue;
+                        continue;
                     }
                     /* Iterate over all sub_tiles to get the sub_tile which the target_cap belongs to. */
                     const t_sub_tile* to_sub_tile = nullptr;
@@ -1774,6 +1774,15 @@ void build_direct_connections_for_one_gsb(const RRGraphView& rr_graph,
                         }
                     }
                     VTR_ASSERT(to_sub_tile != nullptr);
+                    // Check if the to port is the one from the subtile, if not, pass as this is not the destination
+                    bool port_match = false;
+                    for (auto to_sub_tile_port : to_sub_tile->ports) {
+                        if (std::string(to_sub_tile_port.name) == clb_to_clb_directs[i].to_port) {
+                            port_match = true;
+                            break;
+                        }
+                    }
+                    if (!port_match) continue;
                     if (relative_ipin >= to_sub_tile->num_phy_pins) continue;
                     // If this block has capacity > 1 then the pins of z position > 0 are offset
                     // by the number of pins per capacity instance
@@ -1792,7 +1801,7 @@ void build_direct_connections_for_one_gsb(const RRGraphView& rr_graph,
                                                                              to_grid_coordinate.y() + to_grid_type->pin_height_offset[ipin],
                                                                              e_rr_type::IPIN, ipin, ipin_grid_side[0]);
 
-                    /* add edges to the opin_node */
+                    // add edges to the opin_node */
                     if (!opin_node_id) {
                       VTR_ASSERT(opin_node_id);
                     }