Enable bitstream generation with flat routing

openfpga/src/annotation/annotate_rr_graph.cpp

@@ -554,6 +554,12 @@ static void annotate_rr_switch_circuit_models(
        rr_switch_id++) {
     std::string switch_name(
       vpr_device_ctx.rr_graph.rr_switch()[RRSwitchId(rr_switch_id)].name);
+
+    /* Skip flat router-generated internal switches */
+    if (switch_name.rfind(VPR_INTERNAL_SWITCH_NAME, 0) == 0) {
+      continue;
+    }
+
     /* Skip the delayless switch, which is only used by the edges between
      * - SOURCE and OPIN
      * - IPIN and SINK

openfpga/src/annotation/openfpga_annotate_routing.cpp

@@ -5,7 +5,7 @@
 #include "openfpga_annotate_routing.h"
 
 #include "annotate_routing.h"
-#include "old_traceback.h"
+#include "route_utils.h"
 #include "vtr_assert.h"
 #include "vtr_log.h"
 #include "vtr_time.h"
@@ -123,130 +123,42 @@ void annotate_vpr_rr_node_nets(const DeviceContext& device_ctx,
   VTR_LOG("Loaded node-to-net mapping\n");
 }
 
-/********************************************************************
- * This function will find a previous node for a given rr_node
- * from the routing traces
- *
- * It requires a candidate which provided by upstream functions
- * Try to validate a candidate by searching it from driving node list
- * If not validated, try to find a right one in the routing traces
- *******************************************************************/
-static RRNodeId find_previous_node_from_routing_traces(
-  const RRGraphView& rr_graph, t_trace* routing_trace_head,
-  const RRNodeId& prev_node_candidate, const RRNodeId& cur_rr_node) {
-  RRNodeId prev_node = prev_node_candidate;
-
-  /* For a valid prev_node, ensure prev node is one of the driving nodes for
-   * this rr_node! */
-  if (prev_node) {
-    /* Try to spot the previous node in the incoming node list of this rr_node
-     */
-    bool valid_prev_node = false;
-    for (const RREdgeId& in_edge : rr_graph.node_in_edges(cur_rr_node)) {
-      if (prev_node == rr_graph.edge_src_node(in_edge)) {
-        valid_prev_node = true;
-        break;
-      }
-    }
-
-    /* Early exit if we already validate the node */
-    if (true == valid_prev_node) {
-      return prev_node;
-    }
-
-    /* If we cannot find one, it could be possible that this rr_node branches
-     * from an earlier point in the routing tree
-     *
-     *            +----- ... --->prev_node
-     *            |
-     *  src_node->+
-     *            |
-     *            +-----+ rr_node
-     *
-     * Our job now is to start from the head of the traces and find the
-     * prev_node that drives this rr_node
-     *
-     * This search will find the first-fit and finish.
-     * This is reasonable because if there is a second-fit, it should be a
-     * longer path which should be considered in routing optimization
-     */
-    if (false == valid_prev_node) {
-      t_trace* tptr = routing_trace_head;
-      while (tptr != nullptr) {
-        RRNodeId cand_prev_node = RRNodeId(tptr->index);
-        bool is_good_cand = false;
-        for (const RREdgeId& in_edge : rr_graph.node_in_edges(cur_rr_node)) {
-          if (cand_prev_node == rr_graph.edge_src_node(in_edge)) {
-            is_good_cand = true;
-            break;
-          }
-        }
-
-        if (true == is_good_cand) {
-          /* Update prev_node */
-          prev_node = cand_prev_node;
-          break;
-        }
-
-        /* Move on to the next */
-        tptr = tptr->next;
-      }
-    }
-  }
-
-  return prev_node;
-}
-
 /********************************************************************
  * Create a mapping between each rr_node and its previous node
  * based on VPR routing results
  * - Unmapped rr_node will have an invalid id of previous rr_node
  *******************************************************************/
 void annotate_rr_node_previous_nodes(
   const DeviceContext& device_ctx, const ClusteringContext& clustering_ctx,
-  const RoutingContext& routing_ctx,
   VprRoutingAnnotation& vpr_routing_annotation, const bool& verbose) {
   size_t counter = 0;
   VTR_LOG("Annotating previous nodes for rr_node...");
   VTR_LOGV(verbose, "\n");
 
-  for (auto net_id : clustering_ctx.clb_nlist.nets()) {
+  auto& netlist = clustering_ctx.clb_nlist;
+
+  for (auto net_id : netlist.nets()) {
     /* Ignore nets that are not routed */
-    if (true == clustering_ctx.clb_nlist.net_is_ignored(net_id)) {
+    if (true == netlist.net_is_ignored(net_id)) {
       continue;
     }
     /* Ignore used in local cluster only, reserved one CLB pin */
-    if (false == clustering_ctx.clb_nlist.net_sinks(net_id).size()) {
+    if (false == netlist.net_sinks(net_id).size()) {
       continue;
     }
 
-    /* Cache Previous nodes */
-    RRNodeId prev_node = RRNodeId::INVALID();
-
-    t_trace* tptr = TracebackCompat::traceback_from_route_tree(
-      routing_ctx.route_trees[net_id].value());
-    t_trace* head = tptr;
-    while (tptr != nullptr) {
-      RRNodeId rr_node = RRNodeId(tptr->index);
-
-      /* Find the right previous node */
-      prev_node = find_previous_node_from_routing_traces(
-        device_ctx.rr_graph, head, prev_node, rr_node);
-
-      /* Only update mapped nodes */
-      if (prev_node) {
-        vpr_routing_annotation.set_rr_node_prev_node(device_ctx.rr_graph,
-                                                     rr_node, prev_node);
-        counter++;
-      }
-
-      /* Update prev_node */
-      prev_node = rr_node;
+    auto& tree = get_route_tree_from_cluster_net_id(net_id);
+    if (!tree) {
+      continue;
+    }
 
-      /* Move on to the next */
-      tptr = tptr->next;
+    for (auto& rt_node : tree->all_nodes()) {
+      RRNodeId rr_node = rt_node.inode;
+      auto parent = rt_node.parent();
+      vpr_routing_annotation.set_rr_node_prev_node(
+        device_ctx.rr_graph, rr_node,
+        parent ? parent->inode : RRNodeId::INVALID());
     }
-    free_traceback(head);
   }
 
   VTR_LOG("Done with %d nodes mapping\n", counter);

openfpga/src/annotation/openfpga_annotate_routing.h

@@ -28,7 +28,6 @@ void annotate_vpr_rr_node_nets(const DeviceContext& device_ctx,
 
 void annotate_rr_node_previous_nodes(
   const DeviceContext& device_ctx, const ClusteringContext& clustering_ctx,
-  const RoutingContext& routing_ctx,
   VprRoutingAnnotation& vpr_routing_annotation, const bool& verbose);
 
 } /* end namespace openfpga */

openfpga/src/base/openfpga_link_arch_template.h

@@ -94,7 +94,6 @@ int link_arch_template(T& openfpga_ctx, const Command& cmd,
                             cmd_context.option_enable(cmd, opt_verbose));
 
   annotate_rr_node_previous_nodes(g_vpr_ctx.device(), g_vpr_ctx.clustering(),
-                                  g_vpr_ctx.routing(),
                                   openfpga_ctx.mutable_vpr_routing_annotation(),
                                   cmd_context.option_enable(cmd, opt_verbose));
 

openfpga/src/mux_lib/mux_library_builder.cpp

@@ -52,11 +52,18 @@ static void build_routing_arch_mux_library(
         VTR_ASSERT(1 == driver_switches.size());
         const CircuitModelId& rr_switch_circuit_model =
           vpr_device_annotation.rr_switch_circuit_model(driver_switches[0]);
+
+        /* Skip flat router-generated internal switches (not relevant) */
+        auto switch_name = rr_graph.rr_switch_inf(driver_switches[0]).name;
+        if (switch_name.rfind(VPR_INTERNAL_SWITCH_NAME, 0) == 0) {
+          continue;
+        }
+
         /* we should select a circuit model for the routing resource switch */
         if (CircuitModelId::INVALID() == rr_switch_circuit_model) {
           VTR_LOG_ERROR(
             "Unable to find the circuit model for rr_switch '%s'!\n",
-            rr_graph.rr_switch_inf(driver_switches[0]).name.c_str());
+            switch_name.c_str());
           VTR_LOG("Node type: %s\n", rr_graph.node_type_string(node));
           VTR_LOG("Node coordinate: %s\n",
                   rr_graph.node_coordinate_to_string(node).c_str());