Support IPIN connections from all four sides incoming wires of the GSB

openfpga/src/annotation/annotate_rr_graph.cpp

@@ -397,6 +397,16 @@ static RRGSB build_rr_gsb(const DeviceContext& vpr_device_ctx,
   /* Build OPIN node lists for connection blocks */
   rr_gsb.build_cb_opin_nodes(vpr_device_ctx.rr_graph);
 
+  for (size_t side = 0; side < rr_gsb.get_num_sides(); ++side) {
+    SideManager side_manager(side);
+    VTR_LOG_DEBUG(
+      "RRGSB at (%lu, %lu) has %lu chan nodes, %lu ipin nodes, and %lu opin "
+      "nodes.\n",
+      rr_gsb.get_x(), rr_gsb.get_y(),
+      rr_gsb.chan_node_size(side_manager.get_side()),
+      rr_gsb.ipin_node_size(side_manager.get_side()),
+      rr_gsb.opin_node_size(side_manager.get_side()));
+  }
   return rr_gsb;
 }
 

openfpga/src/annotation/write_xml_device_rr_gsb.cpp

@@ -51,14 +51,33 @@ static void write_rr_gsb_ipin_connection_to_xml(std::fstream& fp,
       }
 
       enum e_side chan_side = rr_gsb.get_cb_chan_side(gsb_side);
+      int driver_node_index = -1;
+
       SideManager chan_side_manager(chan_side);
 
-      /* For channel node, we do not know the node direction
-       * But we are pretty sure it is either IN_PORT or OUT_PORT
-       * So we just try and find what is valid
-       */
-      int driver_node_index =
-        rr_gsb.get_chan_node_index(chan_side, driver_node);
+      driver_node_index = rr_gsb.get_chan_node_index(chan_side, driver_node);
+
+      if (-1 == driver_node_index) {
+        for (size_t side = 0; side < NUM_2D_SIDES; ++side) {
+          chan_side_manager.set_side(side);
+          chan_side = chan_side_manager.get_side();
+          for (PORTS port_direc : {IN_PORT, OUT_PORT}) {
+            /* For channel node, we do not know the node direction
+             * But we are pretty sure it is either IN_PORT or OUT_PORT
+             * So we just try and find what is valid
+             */
+            driver_node_index =
+              rr_gsb.get_chan_node_index(chan_side, driver_node);
+            if (-1 != driver_node_index) {
+              break;
+            }
+          }
+          if (-1 != driver_node_index) {
+            break;
+          }
+        }
+      }
+
       /* We must have a valide node index */
       VTR_ASSERT(-1 != driver_node_index);