[engine] now repacker find only routable pins when given a net to search routing traces

openfpga/src/repack/repack.cpp

@@ -11,6 +11,7 @@
 #include "build_physical_lb_rr_graph.h"
 #include "lb_router.h"
 #include "lb_router_utils.h"
+#include "pb_graph_utils.h"
 #include "pb_type_utils.h"
 #include "physical_pb_utils.h"
 #include "repack.h"
@@ -290,7 +291,7 @@ static std::vector<int> find_pb_route_by_atom_net(
 
   if (pb_route_indices.empty()) {
     for (int pin : candidate_pool) {
-      if (pb->pb_route.at(pin).pb_graph_pin->parent_node->is_root() && source_pb_pin->port->type == pb->pb_route.at(pin).pb_graph_pin->port->type) {
+      if (pb->pb_route.at(pin).pb_graph_pin->parent_node->is_root() && is_pb_graph_pins_share_interc(source_pb_pin, pb->pb_route.at(pin).pb_graph_pin)) {
         pb_route_indices.push_back(pin);
       }
     }

openfpga/src/utils/pb_graph_utils.cpp

@@ -70,4 +70,28 @@ t_interconnect* pb_graph_pin_interc(t_pb_graph_pin* pb_graph_pin,
   return interc;
 }
 
+/********************************************************************
+ * This function identifies if two pb graph pins share at least one interconnect model
+ * The two pins should be in the same type of port, for example, both are inputs.
+ * Each pin may drive a number of outgoing edges while each edge represents different interconnect model
+ * By iterating over outgoing edges for each pin, common interconnect model may be found 
+ *******************************************************************/
+bool is_pb_graph_pins_share_interc(const t_pb_graph_pin* pinA, const t_pb_graph_pin* pinB) {
+  if (pinA->port->type != pinB->port->type) {
+    return false;
+  }
+  std::vector<t_interconnect*> pinA_interc_list;
+  for (auto out_edge : pinA->output_edges) {
+    if (pinA_interc_list.end() == std::find(pinA_interc_list.begin(), pinA_interc_list.end(), out_edge->interconnect)) {
+      pinA_interc_list.push_back(out_edge->interconnect);
+    }
+  } 
+  for (auto out_edge : pinB->output_edges) {
+    if (pinA_interc_list.end() != std::find(pinA_interc_list.begin(), pinA_interc_list.end(), out_edge->interconnect)) {
+      return true;
+    }
+  }
+  return false;
+}
+
 } /* end namespace openfpga */

openfpga/src/utils/pb_graph_utils.h

@@ -22,6 +22,8 @@ std::vector<t_pb_graph_pin*> pb_graph_pin_inputs(
 t_interconnect* pb_graph_pin_interc(t_pb_graph_pin* pb_graph_pin,
                                     t_mode* selected_mode);
 
+bool is_pb_graph_pins_share_interc(const t_pb_graph_pin* pinA, const t_pb_graph_pin* pinB);
+
 } /* end namespace openfpga */
 
 #endif