Merge pull request #2867 from verilog-to-routing/fix-flat-bitgen

vaughnbetz · web-flow · commit 796f652aff25 · 2025-04-28T18:29:38.000-04:00
More fixes to sync_netlists_to_routing_flat
diff --git a/vpr/src/base/netlist_writer.cpp b/vpr/src/base/netlist_writer.cpp
@@ -1275,7 +1275,10 @@ class NetlistWriterVisitor : public NetlistVisitor {
 
         //Add the single output connection
         {
-            auto atom_net_id = top_pb_route[sink_cluster_pin_idx].atom_net_id; //Connected net in atom netlist
+            /* Check if the output is connected */
+            AtomNetId atom_net_id = AtomNetId::INVALID();
+            if (top_pb_route.count(sink_cluster_pin_idx))
+                atom_net_id = top_pb_route[sink_cluster_pin_idx].atom_net_id; //Connected net in atom netlist
 
             std::string net;
             if (!atom_net_id) {
diff --git a/vpr/src/base/read_netlist.cpp b/vpr/src/base/read_netlist.cpp
@@ -823,7 +823,7 @@ static void processPorts(pugi::xml_node Parent, t_pb* pb, t_pb_routes& pb_route,
                     //Why does this not use the output pin used to deterimine the rr node index?
                     pb_route.insert(std::make_pair(rr_node_index, t_pb_route()));
                     pb_route[rr_node_index].driver_pb_pin_id = pin_node[0][0]->pin_count_in_cluster;
-                    pb_route[rr_node_index].pb_graph_pin = pin_node[0][0];
+                    pb_route[rr_node_index].pb_graph_pin = &pb->pb_graph_node->output_pins[out_port][i];
 
                     found = false;
                     for (j = 0; j < pin_node[0][0]->num_output_edges; j++) {
diff --git a/vpr/src/base/vpr_api.cpp b/vpr/src/base/vpr_api.cpp
@@ -111,6 +111,12 @@ static void free_complex_block_types();
 static void free_device(const t_det_routing_arch& routing_arch);
 static void free_circuit();
 
+/** Set all port equivalences in the architecture to NONE. This is used in the 
+ * case of the flat router where port equivalence does not make sense.
+ * We could just keep it set and ignore it, but that prevents compatibility
+ * with OpenFPGA which takes it seriously. */
+static void unset_port_equivalences(DeviceContext& device_ctx);
+
 /* Local subroutines end */
 
 ///@brief Display general VPR information
@@ -365,6 +371,25 @@ void vpr_init_with_options(const t_options* options, t_vpr_setup* vpr_setup, t_a
     device_ctx.pad_loc_type = vpr_setup->PlacerOpts.pad_loc_type;
 }
 
+/** Port equivalence does not make sense during flat routing.
+ * Remove port equivalence from all ports in the architecture */
+static void unset_port_equivalences(DeviceContext& device_ctx) {
+    for (auto& physical_type : device_ctx.physical_tile_types) {
+        for (auto& sub_tile : physical_type.sub_tiles) {
+            for (auto& port : sub_tile.ports) {
+                port.equivalent = PortEquivalence::NONE;
+            }
+        }
+    }
+    for (auto& logical_type : device_ctx.logical_block_types) {
+        if (!logical_type.pb_type)
+            continue;
+        for (int i = 0; i < logical_type.pb_type->num_ports; i++) {
+            logical_type.pb_type->ports[i].equivalent = PortEquivalence::NONE;
+        }
+    }
+}
+
 bool vpr_flow(t_vpr_setup& vpr_setup, t_arch& arch) {
     if (vpr_setup.exit_before_pack) {
         VTR_LOG_WARN("Exiting before packing as requested.\n");
@@ -443,6 +468,10 @@ bool vpr_flow(t_vpr_setup& vpr_setup, t_arch& arch) {
 
     bool is_flat = vpr_setup.RouterOpts.flat_routing;
     const Netlist<>& router_net_list = is_flat ? (const Netlist<>&)g_vpr_ctx.atom().netlist() : (const Netlist<>&)g_vpr_ctx.clustering().clb_nlist;
+    if (is_flat) {
+        VTR_LOG_WARN("Disabling port equivalence in the architecture since flat routing is enabled.\n");
+        unset_port_equivalences(g_vpr_ctx.mutable_device());
+    }
     RouteStatus route_status;
     { //Route
         route_status = vpr_route_flow(router_net_list, vpr_setup, arch, is_flat);
diff --git a/vpr/src/pack/cluster_legalizer.cpp b/vpr/src/pack/cluster_legalizer.cpp
@@ -1571,8 +1571,7 @@ void ClusterLegalizer::clean_cluster(LegalizationClusterId cluster_id) {
     // Load the pb_route so we can free the cluster router data.
     // The pb_route is used when creating a netlist from the legalized clusters.
     std::vector<t_intra_lb_net>* saved_lb_nets = cluster.router_data->saved_lb_nets;
-    t_pb_graph_node* pb_graph_node = cluster.pb->pb_graph_node;
-    cluster.pb->pb_route = alloc_and_load_pb_route(saved_lb_nets, pb_graph_node);
+    cluster.pb->pb_route = alloc_and_load_pb_route(saved_lb_nets, cluster.type, intra_lb_pb_pin_lookup_);
     // Free the router data.
     free_router_data(cluster.router_data);
     cluster.router_data = nullptr;
@@ -1632,6 +1631,7 @@ ClusterLegalizer::ClusterLegalizer(const AtomNetlist& atom_netlist,
     log_verbosity_ = log_verbosity;
     VTR_ASSERT(g_vpr_ctx.atom().lookup().atom_pb_bimap().is_empty());
     atom_pb_lookup_ = AtomPBBimap();
+    intra_lb_pb_pin_lookup_ = IntraLbPbPinLookup(g_vpr_ctx.device().logical_block_types);
 }
 
 void ClusterLegalizer::reset() {
diff --git a/vpr/src/pack/cluster_legalizer.h b/vpr/src/pack/cluster_legalizer.h
@@ -23,6 +23,7 @@
 #include "vtr_vector.h"
 #include "vtr_vector_map.h"
 #include "atom_pb_bimap.h"
+#include "vpr_utils.h"
 
 // Forward declarations
 class Prepacker;
@@ -524,6 +525,8 @@ class ClusterLegalizer {
     inline const AtomPBBimap& atom_pb_lookup() const { return atom_pb_lookup_; }
     inline AtomPBBimap& mutable_atom_pb_lookup() { return atom_pb_lookup_; }
 
+    inline const IntraLbPbPinLookup& intra_lb_pb_pin_lookup() const { return intra_lb_pb_pin_lookup_; }
+
     /// @brief Destructor of the class. Frees allocated data.
     ~ClusterLegalizer();
 
@@ -595,4 +598,7 @@ class ClusterLegalizer {
     /// @brief A two way map between AtomBlockIds and pb types. This is a copy
     /// of the AtomPBBimap in the global context's AtomLookup
     AtomPBBimap atom_pb_lookup_;
+
+    /// @brief A lookup table for the pin mapping of the intra-lb pb pins.
+    IntraLbPbPinLookup intra_lb_pb_pin_lookup_;
 };
diff --git a/vpr/src/pack/cluster_router.cpp b/vpr/src/pack/cluster_router.cpp
@@ -108,7 +108,23 @@ static bool is_route_success(t_lb_router_data* router_data);
 static t_lb_trace* find_node_in_rt(t_lb_trace* rt, int rt_index);
 static void reset_explored_node_tb(t_lb_router_data* router_data);
 static void save_and_reset_lb_route(t_lb_router_data* router_data);
-static void load_trace_to_pb_route(t_pb_routes& pb_route, const int total_pins, const AtomNetId net_id, const int prev_pin_id, const t_lb_trace* trace);
+
+/**
+ * @brief Recurse through route tree trace to populate pb pin to atom net lookup array.
+ * 
+ * @param pb_route Array of pb pin to atom net lookup to be populated in this routine.
+ * @param net_id Atom net ID of the current net.
+ * @param prev_pin_id ID of the previous pin in the route tree trace.
+ * @param trace Current trace node in the route tree.
+ * @param logic_block_type Logic block type of the current cluster.
+ * @param intra_lb_pb_pin_lookup Intra-logic block pin lookup to get t_pb_graph_pin from a pin ID.
+ */
+static void load_trace_to_pb_route(t_pb_routes& pb_route,
+                                   const AtomNetId net_id,
+                                   const int prev_pin_id,
+                                   const t_lb_trace* trace,
+                                   t_logical_block_type_ptr logic_block_type,
+                                   const IntraLbPbPinLookup& intra_lb_pb_pin_lookup);
 
 static std::string describe_lb_type_rr_node(int inode,
                                             const t_lb_router_data* router_data);
@@ -543,15 +559,14 @@ bool try_intra_lb_route(t_lb_router_data* router_data,
  * Accessor Functions
  ******************************************************************************************/
 
-/* Creates an array [0..num_pb_graph_pins-1] lookup for intra-logic block routing.  Given pb_graph_pin id for clb, lookup atom net that uses that pin.
- * If pin is not used, stores OPEN at that pin location */
-t_pb_routes alloc_and_load_pb_route(const std::vector<t_intra_lb_net>* intra_lb_nets, t_pb_graph_node* pb_graph_head) {
+t_pb_routes alloc_and_load_pb_route(const std::vector<t_intra_lb_net>* intra_lb_nets,
+                                    t_logical_block_type_ptr logic_block_type,
+                                    const IntraLbPbPinLookup& intra_lb_pb_pin_lookup) {
     const std::vector<t_intra_lb_net>& lb_nets = *intra_lb_nets;
-    int total_pins = pb_graph_head->total_pb_pins;
     t_pb_routes pb_route;
 
-    for (int inet = 0; inet < (int)lb_nets.size(); inet++) {
-        load_trace_to_pb_route(pb_route, total_pins, lb_nets[inet].atom_net_id, OPEN, lb_nets[inet].rt_tree);
+    for (const auto& lb_net : lb_nets) {
+        load_trace_to_pb_route(pb_route, lb_net.atom_net_id, OPEN, lb_net.rt_tree, logic_block_type, intra_lb_pb_pin_lookup);
     }
 
     return pb_route;
@@ -581,24 +596,31 @@ void free_intra_lb_nets(std::vector<t_intra_lb_net>* intra_lb_nets) {
  * Internal Functions
  ****************************************************************************/
 
-/* Recurse through route tree trace to populate pb pin to atom net lookup array */
-static void load_trace_to_pb_route(t_pb_routes& pb_route, const int total_pins, const AtomNetId net_id, const int prev_pin_id, const t_lb_trace* trace) {
+static void load_trace_to_pb_route(t_pb_routes& pb_route,
+                                   const AtomNetId net_id,
+                                   const int prev_pin_id,
+                                   const t_lb_trace* trace,
+                                   t_logical_block_type_ptr logic_block_type,
+                                   const IntraLbPbPinLookup& intra_lb_pb_pin_lookup) {
     int ipin = trace->current_node;
     int driver_pb_pin_id = prev_pin_id;
     int cur_pin_id = OPEN;
+    const int total_pins = logic_block_type->pb_graph_head->total_pb_pins;
     if (ipin < total_pins) {
         /* This routing node corresponds with a pin.  This node is virtual (ie. sink or source node) */
         cur_pin_id = ipin;
         if (!pb_route.count(ipin)) {
             pb_route.insert(std::make_pair(cur_pin_id, t_pb_route()));
             pb_route[cur_pin_id].atom_net_id = net_id;
             pb_route[cur_pin_id].driver_pb_pin_id = driver_pb_pin_id;
+            const t_pb_graph_pin* pb_graph_pin = intra_lb_pb_pin_lookup.pb_gpin(logic_block_type->index, cur_pin_id);
+            pb_route[cur_pin_id].pb_graph_pin = pb_graph_pin;
         } else {
             VTR_ASSERT(pb_route[cur_pin_id].atom_net_id == net_id);
         }
     }
-    for (int itrace = 0; itrace < (int)trace->next_nodes.size(); itrace++) {
-        load_trace_to_pb_route(pb_route, total_pins, net_id, cur_pin_id, &trace->next_nodes[itrace]);
+    for (const auto& nxt_trace : trace->next_nodes) {
+        load_trace_to_pb_route(pb_route, net_id, cur_pin_id, &nxt_trace, logic_block_type, intra_lb_pb_pin_lookup);
     }
 }
 
diff --git a/vpr/src/pack/cluster_router.h b/vpr/src/pack/cluster_router.h
@@ -22,8 +22,19 @@ void set_reset_pb_modes(t_lb_router_data* router_data, const t_pb* pb, const boo
 bool try_intra_lb_route(t_lb_router_data* router_data, int verbosity, t_mode_selection_status* mode_status);
 void reset_intra_lb_route(t_lb_router_data* router_data);
 
-/* Accessor Functions */
-t_pb_routes alloc_and_load_pb_route(const std::vector<t_intra_lb_net>* intra_lb_nets, t_pb_graph_node* pb_graph_head);
+/**
+ * @brief Creates an array [0..num_pb_graph_pins-1] for intra-logic block routing lookup. 
+ * Given a pb_graph_pin ID for a CLB, this lookup returns t_pb_route corresponding to that
+ * pin.
+ *
+ * @param intra_lb_nets Vector of intra-logic block nets.
+ * @param logic_block_type Logic block type of the current cluster.
+ * @param intra_lb_pb_pin_lookup Intra-logic block pin lookup to get t_pb_graph_pin from a pin ID.
+ * @return t_pb_routes An array [0..num_pb_graph_pins-1] for intra-logic block routing lookup.
+ */
+t_pb_routes alloc_and_load_pb_route(const std::vector<t_intra_lb_net>* intra_lb_nets,
+                                    t_logical_block_type_ptr logic_block_type,
+                                    const IntraLbPbPinLookup& intra_lb_pb_pin_lookup);
 void free_pb_route(t_pb_route* free_pb_route);
 
 #endif
diff --git a/vpr/src/pack/post_routing_pb_pin_fixup.cpp b/vpr/src/pack/post_routing_pb_pin_fixup.cpp
@@ -1033,6 +1033,7 @@ void sync_netlists_to_routing(const Netlist<>& net_list,
     /* Create net-to-rr_node mapping */
     vtr::vector<RRNodeId, ClusterNetId> rr_node_nets = annotate_rr_node_nets(clustering_ctx,
                                                                              device_ctx,
+                                                                             atom_ctx,
                                                                              verbose);
 
     IntraLbPbPinLookup intra_lb_pb_pin_lookup(device_ctx.logical_block_types);
diff --git a/vpr/src/pack/sync_netlists_to_routing_flat.cpp b/vpr/src/pack/sync_netlists_to_routing_flat.cpp
@@ -42,23 +42,6 @@ static void fixup_atom_pb_graph_pin_mapping(void);
 
 /* Function definitions */
 
-/** Is the clock net found in the routing results?
- * (If not, clock_modeling is probably ideal and we should preserve clock routing while rebuilding.) */
-inline bool is_clock_net_routed(void) {
-    auto& atom_ctx = g_vpr_ctx.atom();
-    auto& route_ctx = g_vpr_ctx.routing();
-
-    for (auto net_id : atom_ctx.netlist().nets()) {
-        auto& tree = route_ctx.route_trees[net_id];
-        if (!tree)
-            continue;
-        if (route_ctx.is_clock_net[net_id]) /* Clock net has routing */
-            return true;
-    }
-
-    return false;
-}
-
 /** Get the ClusterBlockId for a given RRNodeId. */
 inline ClusterBlockId get_cluster_block_from_rr_node(RRNodeId inode) {
     auto& device_ctx = g_vpr_ctx.device();
@@ -185,18 +168,22 @@ static void sync_pb_routes_to_routing(void) {
     auto& route_ctx = g_vpr_ctx.routing();
     auto& rr_graph = device_ctx.rr_graph;
 
-    /* Was the clock net routed? */
-    bool clock_net_is_routed = is_clock_net_routed();
-
     /* Clear out existing pb_routes: they were made by the intra cluster router and are invalid now */
     for (ClusterBlockId clb_blk_id : cluster_ctx.clb_nlist.blocks()) {
-        /* If we don't have routing for the clock net, don't erase entries associated with a clock net.
-         * Otherwise we won't have data to rebuild them */
+        /* Don't erase entries for nets without routing in place (clocks, globals...) */
         std::vector<int> pins_to_erase;
-        auto& pb_routes = cluster_ctx.clb_nlist.block_pb(clb_blk_id)->pb_route;
+        t_pb_routes& pb_routes = cluster_ctx.clb_nlist.block_pb(clb_blk_id)->pb_route;
         for (auto& [pin, pb_route] : pb_routes) {
-            if (clock_net_is_routed || !route_ctx.is_clock_net[pb_route.atom_net_id])
-                pins_to_erase.push_back(pin);
+            /* 
+             * Given that this function is called when flat routing is enabled,
+             * we can safely assume that the net IDs to index into route_ctx.route_trees
+             * correspond to the atom net IDs.
+             */
+            if (!route_ctx.route_trees[pb_route.atom_net_id]) {
+                /* No route tree: no routing in place, it is global or clock */
+                continue;
+            }
+            pins_to_erase.push_back(pin);
         }
 
         for (int pin : pins_to_erase) {
@@ -276,37 +263,37 @@ static void sync_clustered_netlist_to_routing(void) {
     auto& atom_ctx = g_vpr_ctx.mutable_atom();
     auto& atom_lookup = atom_ctx.lookup();
 
-    bool clock_net_is_routed = is_clock_net_routed();
-
     /* 1. Remove all nets, pins and ports from the clustered netlist.
-     * If the clock net is not routed, don't remove entries for the clock net
-     * otherwise we won't have data to rebuild them. */
+     * Do not remove entries for nets without an existing route tree,
+     * since we don't have the information to rebuild those parts. */
     std::vector<ClusterNetId> nets_to_remove;
     std::vector<ClusterPinId> pins_to_remove;
     std::vector<ClusterPortId> ports_to_remove;
 
     for (auto net_id : clb_netlist.nets()) {
         auto atom_net_id = atom_lookup.atom_net(net_id);
-        if (!clock_net_is_routed && route_ctx.is_clock_net[atom_net_id])
+        if (!route_ctx.route_trees[atom_net_id])
             continue;
 
         nets_to_remove.push_back(net_id);
     }
-    for (auto pin_id : clb_netlist.pins()) {
-        ClusterNetId clb_net_id = clb_netlist.pin_net(pin_id);
-        auto atom_net_id = atom_lookup.atom_net(clb_net_id);
-        if (!clock_net_is_routed && atom_net_id && route_ctx.is_clock_net[atom_net_id])
-            continue;
-
-        pins_to_remove.push_back(pin_id);
-    }
+    /* Mark ports and pins for removal. Don't remove a port if
+     * it has at least one pin remaining */
     for (auto port_id : clb_netlist.ports()) {
-        ClusterNetId clb_net_id = clb_netlist.port_net(port_id, 0);
-        auto atom_net_id = atom_lookup.atom_net(clb_net_id);
-        if (!clock_net_is_routed && atom_net_id && route_ctx.is_clock_net[atom_net_id])
-            continue;
+        size_t skipped_pins = 0;
+
+        for (auto pin_id : clb_netlist.port_pins(port_id)) {
+            ClusterNetId clb_net_id = clb_netlist.pin_net(pin_id);
+            auto atom_net_id = atom_lookup.atom_net(clb_net_id);
+            if (atom_net_id && !route_ctx.route_trees[atom_net_id]) {
+                skipped_pins++;
+            } else {
+                pins_to_remove.push_back(pin_id);
+            }
+        }
 
-        ports_to_remove.push_back(port_id);
+        if (!skipped_pins) // All pins have been removed, remove port
+            ports_to_remove.push_back(port_id);
     }
 
     /* ClusteredNetlist's iterators rely on internal lookups, so we mark for removal
@@ -363,6 +350,7 @@ static void sync_clustered_netlist_to_routing(void) {
 
             t_pb_graph_pin* pb_graph_pin = get_pb_graph_node_pin_from_block_pin(clb, pin_index);
 
+            /* Get or create port */
             ClusterPortId port_id = clb_netlist.find_port(clb, pb_graph_pin->port->name);
             if (!port_id) {
                 PortType port_type;
@@ -378,6 +366,15 @@ static void sync_clustered_netlist_to_routing(void) {
             }
             PinType pin_type = node_type == e_rr_type::OPIN ? PinType::DRIVER : PinType::SINK;
 
+            /* Pin already exists. This means a global net that was not routed (i.e. 'ideal' mode). */
+            if (clb_netlist.port_pin(port_id, pb_graph_pin->pin_number)) {
+                VTR_LOG_WARN("Pin %s of block %s has a global or clock net"
+                             " connected and it has a routing clash with the flat router."
+                             " This may cause inconsistent results.\n",
+                             pb_graph_pin->to_string().c_str(),
+                             clb_netlist.block_name(clb).c_str());
+                continue;
+            }
             ClusterPinId new_pin = clb_netlist.create_pin(port_id, pb_graph_pin->pin_number, clb_net_id, pin_type, pb_graph_pin->pin_count_in_cluster);
             clb_netlist.set_pin_net(new_pin, pin_type, clb_net_id);
         }
@@ -419,6 +416,12 @@ static void fixup_atom_pb_graph_pin_mapping(void) {
 
             /* Find atom port from pbg pin's model port */
             AtomPortId atom_port = atom_ctx.netlist().find_atom_port(atb, atom_pbg_pin->port->model_port);
+
+            /* Not an equivalent port, so no need to do fixup */
+            if (atom_pbg_pin->port->equivalent != PortEquivalence::FULL) {
+                continue;
+            }
+
             for (AtomPinId atom_pin : atom_ctx.netlist().port_pins(atom_port)) {
                 /* Match net IDs from pb_route and atom netlist and connect in lookup */
                 if (pb_route.atom_net_id == atom_ctx.netlist().pin_net(atom_pin)) {
diff --git a/vpr/src/route/annotate_routing.cpp b/vpr/src/route/annotate_routing.cpp
diff --git a/vpr/src/route/annotate_routing.h b/vpr/src/route/annotate_routing.h
