Use a BitSet for detecting accessible tiles

Signed-off-by: Eddie Hung <eddie.hung@amd.com>

src/com/xilinx/rapidwright/rwroute/CUFR.java

@@ -114,7 +114,7 @@ protected RouteNodeGraph createRouteNodeGraph() {
 
     @Override
     protected ConnectionState getConnectionState() {
-        return connectionState.computeIfAbsent(Thread.currentThread(), (k) -> new ConnectionState());
+        return connectionState.computeIfAbsent(Thread.currentThread(), (k) -> new ConnectionState(routingGraph.getTileCount(design)));
     }
 
     @Override

src/com/xilinx/rapidwright/rwroute/PartialCUFR.java

@@ -94,7 +94,7 @@ protected RouteNodeGraph createRouteNodeGraph() {
 
     @Override
     protected ConnectionState getConnectionState() {
-        return connectionState.computeIfAbsent(Thread.currentThread(), (k) -> new ConnectionState());
+        return connectionState.computeIfAbsent(Thread.currentThread(), (k) -> new ConnectionState(routingGraph.getTileCount(design)));
     }
 
     @Override

src/com/xilinx/rapidwright/rwroute/RWRoute.java

@@ -59,6 +59,7 @@
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.BitSet;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.EnumMap;
@@ -247,7 +248,7 @@ protected void initialize() {
         minRerouteCriticality = config.getMinRerouteCriticality();
         criticalConnections = new ArrayList<>();
 
-        connectionState = new ConnectionState();
+        connectionState = new ConnectionState(routingGraph.getTileCount(design));
         routingGraph = createRouteNodeGraph();
         if (config.isTimingDriven()) {
             nodesDelays = new HashMap<>();
@@ -1482,6 +1483,10 @@ protected static class ConnectionState {
         protected final PriorityQueue<PriorityQueueEntry> queue;
         /** The list of nodes marked as a target for this connection */
         protected final List<RouteNode> targets;
+        /** Connection-specific temporary list for RouteNode.getChildren() */
+        protected final List<Node> tempNodeList;
+        /** BitSet of Tile.getUniqueAddress() -es that are above/below/at sink tile */
+        protected final BitSet addressesBelowAboveAndAtSinkTile;
 
         /** Connection to be routed */
         protected Connection connection;
@@ -1496,13 +1501,11 @@ protected static class ConnectionState {
         protected float dlyWeight;
         protected float estDlyWeight;
 
-        /** Connection-specific temporary list for RouteNode.getChildren() */
-        protected List<Node> tempNodeList;
-
-        protected ConnectionState() {
+        protected ConnectionState(int tileCount) {
             queue = new PriorityQueue<>();
             targets = new ArrayList<>();
             tempNodeList = new ArrayList<>();
+            addressesBelowAboveAndAtSinkTile = new BitSet(tileCount);
         }
     }
 
@@ -1731,7 +1734,7 @@ private void exploreAndExpand(ConnectionState state, RouteNode rnode, float upst
                 }
                 switch (childRNode.getType()) {
                     case WIRE:
-                        if (!routingGraph.isAccessible(childRNode, connection)) {
+                        if (!routingGraph.isAccessible(childRNode, state)) {
                             continue;
                         }
                         if (!config.isUseUTurnNodes() && childRNode.getDelay() > 10000) {
@@ -1743,7 +1746,7 @@ private void exploreAndExpand(ConnectionState state, RouteNode rnode, float upst
                     case PINBOUNCE:
                         // A PINBOUNCE can only be a target if this connection has an alternate sink
                         assert(!childRNode.isTarget() || connection.getAltSinkRnodes().isEmpty());
-                        if (!isAccessiblePinbounce(childRNode, connection)) {
+                        if (!isAccessiblePinbounce(childRNode, state)) {
                             continue;
                         }
                         break;
@@ -1789,13 +1792,13 @@ protected boolean isAccessible(RouteNode child, Connection connection) {
     /**
      * Checks if a NODE_PINBOUNCE is suitable to be used for routing to a target.
      * @param child The PINBOUNCE rnode in question.
-     * @param connection The connection to route.
+     * @param state State from the connection that is being routed.
      * @return true, if the PINBOUNCE rnode is in the same column as the target and within one INT tile of the target.
      */
-    protected boolean isAccessiblePinbounce(RouteNode child, Connection connection) {
+    protected boolean isAccessiblePinbounce(RouteNode child, ConnectionState state) {
         assert(child.getType() == RouteNodeType.PINBOUNCE);
 
-        return routingGraph.isAccessible(child, connection);
+        return routingGraph.isAccessible(child, state);
     }
 
     protected boolean isAccessiblePinfeedI(RouteNode child, Connection connection) {
@@ -1958,6 +1961,18 @@ protected void prepareRouteConnection(ConnectionState state) {
         // Sets the sink rnode(s) of the connection as the target(s)
         connection.setAllTargets(state);
 
+        Tile sinkTile = connection.getSinkRnode().getTile();
+        state.addressesBelowAboveAndAtSinkTile.clear();
+        state.addressesBelowAboveAndAtSinkTile.set(sinkTile.getUniqueAddress());
+        Tile aboveSinkTile = sinkTile.getTileXYNeighbor(0, 1);
+        if (aboveSinkTile != null) {
+            state.addressesBelowAboveAndAtSinkTile.set(aboveSinkTile.getUniqueAddress());
+        }
+        Tile belowSinkTile = sinkTile.getTileXYNeighbor(0, -1);
+        if (belowSinkTile != null) {
+            state.addressesBelowAboveAndAtSinkTile.set(belowSinkTile.getUniqueAddress());
+        }
+
         // Adds the source rnode to the queue
         RouteNode sourceRnode = connection.getSourceRnode();
         assert(sourceRnode.getPrev() == null);