Cleanup

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

@@ -30,7 +30,6 @@
 import com.xilinx.rapidwright.design.Net;
 import com.xilinx.rapidwright.design.SitePinInst;
 import com.xilinx.rapidwright.device.Node;
-import com.xilinx.rapidwright.device.Tile;
 import com.xilinx.rapidwright.timing.TimingEdge;
 import com.xilinx.rapidwright.timing.delayestimator.DelayEstimatorBase;
 
@@ -219,6 +218,10 @@ public boolean useRnodesWithMultiDrivers() {
     }
 
     public void addRnode(RouteNode rn) {
+        xMinBB = (short) Math.min(xMinBB, rn.getBeginTileXCoordinate() - 1);
+        xMaxBB = (short) Math.max(xMaxBB, rn.getEndTileXCoordinate() + 1);
+        yMinBB = (short) Math.min(yMinBB, rn.getBeginTileYCoordinate() - 1);
+        yMaxBB = (short) Math.max(yMaxBB, rn.getEndTileYCoordinate() + 1);
         rnodes.add(rn);
     }
 
@@ -401,24 +404,6 @@ public void enlargeBoundingBox(int horizontalIncrement, int verticalIncrement) {
         yMinBB = yMinBB < 0? -1:yMinBB;
     }
 
-    public void fitBoundingBoxToRouting() {
-        int xmin = Integer.MAX_VALUE;
-        int xmax = Integer.MIN_VALUE;
-        int ymin = Integer.MAX_VALUE;
-        int ymax = Integer.MIN_VALUE;
-        for (RouteNode rnode : rnodes) {
-            Tile beginTile = rnode.node.getTile();
-            xmin = (short) Math.min(xmin, beginTile.getTileXCoordinate());
-            xmax = (short) Math.max(xmax, rnode.getEndTileXCoordinate());
-            ymin = (short) Math.min(ymin, beginTile.getTileYCoordinate());
-            ymax = (short) Math.max(ymax, rnode.getEndTileYCoordinate());
-        }
-        xMinBB = (short) Math.min(xMinBB, xmin - 1);
-        xMaxBB = (short) Math.max(xMaxBB, xmax + 1);
-        yMinBB = (short) Math.min(yMinBB, ymin - 1);
-        yMaxBB = (short) Math.max(yMaxBB, ymax + 1);
-    }
-
     @Override
     public int hashCode() {
         return id;

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

@@ -58,7 +58,7 @@
  * Adapted from RapidWright APIs.
  */
 public class GlobalSignalRouting {
-    final private static HashSet<String> lutOutputPinNames;
+    private static final HashSet<String> lutOutputPinNames;
     static {
         lutOutputPinNames = new HashSet<>();
         for (String cle : new String[]{"L", "M"}) {

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

@@ -28,8 +28,6 @@
 import java.util.List;
 
 import com.xilinx.rapidwright.design.Net;
-import com.xilinx.rapidwright.design.SitePinInst;
-import com.xilinx.rapidwright.device.Tile;
 
 /**
  * A wrapper class of {@link Net} with additional information for the router.
@@ -85,10 +83,8 @@ public void computeHPWLAndCenterCoordinates(int[] nextLagunaColumn, int[] prevLa
                 sourceRnodeAdded = true;
                 count++;
             }
-            SitePinInst sink = connection.getSink();
-            Tile sinkTile = sink.getTile();
-            int x = sinkTile.getTileXCoordinate();
-            int y = sinkTile.getTileYCoordinate();
+            short x = connection.getSinkRnode().getEndTileXCoordinate();
+            short y = connection.getSinkRnode().getEndTileYCoordinate();
             xMin = Integer.min(xMin, x);
             yMin = Integer.min(yMin, y);
             xMax = Integer.max(xMax, x);

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

@@ -54,7 +54,7 @@
  */
 public class PartialRouter extends RWRoute{
 
-    final protected boolean softPreserve;
+    protected final boolean softPreserve;
 
     protected Set<NetWrapper> partiallyPreservedNets;
 
@@ -112,31 +112,29 @@ public PartialRouter(Design design, RWRouteConfig config, Collection<SitePinInst
      * @return True if arc is part of an existing route.
      */
     private boolean isPartOfExistingRoute(Node start, Node end) {
-        // End node must be preserved
-        if (!routingGraph.isPreserved(end))
-            return false;
-
-        // End node must have been created already
+        // End node can only be part of existing route if it is in the graph already
         RouteNode endRnode = routingGraph.getNode(end);
         if (endRnode == null)
             return false;
 
-        // Only check if end node has not been visited
+        // If end node has been visited already
         if (endRnode.isVisited()) {
             // Visited possibly from a different arc uphill of end, or possibly from
             // the same start -> end arc during prepareRouteConnection()
             return false;
         }
 
-        // Presence means that the only arc allowed to enter this end node is if it came from prev
+        // Presence of a prev pointer means that only that arc allowed to enter this end node
         RouteNode prev = endRnode.getPrev();
         if (prev != null) {
             assert((prev.getNode() == start) == prev.getNode().equals(start));
             if (prev.getNode() == start) {
+                assert(routingGraph.isPreserved(end));
                 return true;
             }
         }
 
+        // No presence means that it is used by a fully preserved net which needs no routing
         return false;
     }
 
@@ -229,12 +227,13 @@ protected void determineRoutingTargets() {
             for (Connection connection : netWrapper.getConnections()) {
                 if (connection.getSink().isRouted()) {
                     finishRouteConnection(connection, connection.getSinkRnode());
-                    connection.fitBoundingBoxToRouting();
                     assert(connection.getSink().isRouted());
                 }
             }
         }
 
+        routingGraph.resetExpansion();
+
         // Mark each static sink node -- if it exists -- as being used, unpreserving any nets
         // using those nodes (likely bounce points) as needed
         for (Map.Entry<Net,List<SitePinInst>> e : staticNetAndRoutingTargets.entrySet()) {
@@ -389,6 +388,11 @@ protected void unpreserveNet(Net net) {
                 Node start = (pip.isReversed()) ? pip.getEndNode() : pip.getStartNode();
                 Node end = (pip.isReversed()) ? pip.getStartNode() : pip.getEndNode();
 
+                // Do not include arcs that the router wouldn't explore
+                // e.g. those that leave the INT tile, since we project pins to their INT tile
+                if (routingGraph.isExcluded(start, end))
+                    continue;
+
                 // Since net already exists, all the nodes it uses must already
                 // have been created
                 RouteNode rstart = routingGraph.getNode(start);
@@ -403,9 +407,8 @@ protected void unpreserveNet(Net net) {
                 boolean endPreserved = routingGraph.unpreserve(end);
                 assert(rendAdded == endPreserved);
 
-                // Check the prev pointer consistent with PIP
-                // (it may be null because isPartOfExistingRoute() will erase prev once rend was created)
-                assert(rend.getPrev() == null || rend.getPrev().equals(rstart));
+                // Check the prev pointer is consistent with PIP
+                assert(rend.getPrev() == rstart);
             }
         } else {
             // Net needs to be created
@@ -441,7 +444,6 @@ protected void unpreserveNet(Net net) {
                 if (netnewConnection.getSink().isRouted()) {
                     finishRouteConnection(netnewConnection, netnewConnection.getSinkRnode());
                     assert(netnewConnection.getSink().isRouted());
-                    netnewConnection.fitBoundingBoxToRouting();
                 }
             }
 
@@ -455,6 +457,9 @@ protected void unpreserveNet(Net net) {
             }
         }
 
+        routingGraph.resetExpansion();
+
+        // TODO: Avoid using a set by backtracking from sinks (and stubs) until an already-reset node is seen
         for (RouteNode rnode : rnodes) {
             Node toBuild = rnode.getNode();
             // Check already unpreserved above
@@ -467,7 +472,8 @@ protected void unpreserveNet(Net net) {
                 if (parent == null)
                     continue;
 
-                // Reset its list of children so that they may be regenerated to include newly unpreserved node
+                // Reset its list of children so that they may be regenerated to include the
+                // newly unpreserved node
                 parent.resetChildren();
             }
 

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

@@ -138,7 +138,7 @@ public class RWRoute{
     private long nodesPopped;
 
     /** The maximum criticality constraint of connection */
-    final private static float MAX_CRITICALITY = 0.99f;
+    private static final float MAX_CRITICALITY = 0.99f;
     /** The minimum criticality of connections that should be re-routed, updated after each iteration */
     private float minRerouteCriticality;
     /** The list of critical connections */
@@ -243,7 +243,7 @@ protected TimingManager createTimingManager(ClkRouteTiming clkTiming, Collection
     protected void determineRoutingTargets() {
         categorizeNets();
 
-        // Wait for all outstanding RoutingGraph.asyncPreserve() calls to complete
+        // Wait for all outstanding RouteNodeGraph.asyncPreserve() calls to complete
         // FIXME: Calling thread does nothing while waiting
         routingGraph.awaitPreserve();
     }
@@ -505,7 +505,7 @@ protected NetWrapper createNetWrapperAndConnections(Net net) {
                     }
                     sourceINTRnode = getOrCreateRouteNode(sourceINTNode, RouteNodeType.PINFEED_O);
 
-                    // Pre-emptively set up alternate source
+                    // Pre-emptively set up alternate source since we are expanding from both sources
                     SitePinInst altSource = net.getAlternateSource();
                     if (altSource == null) {
                         altSource = DesignTools.getLegalAlternativeOutputPin(net);
@@ -515,6 +515,7 @@ protected NetWrapper createNetWrapperAndConnections(Net net) {
                         }
                     }
                     if (altSource != null) {
+                        assert(!altSource.equals(source));
                         Node altSourceNode = RouterHelper.projectOutputPinToINTNode(altSource);
                         if (altSourceNode != null) {
                             altSourceINTRnode = getOrCreateRouteNode(altSourceNode, RouteNodeType.PINFEED_O);
@@ -975,6 +976,9 @@ private void updateCost() {
                 overUsedRnodes.add(rnode);
                 rnode.setPresentCongestionCost(1 + (overuse + 1) * presentCongestionFactor);
                 rnode.setHistoricalCongestionCost(rnode.getHistoricalCongestionCost() + overuse * historicalCongestionFactor);
+            } else {
+                assert(overuse < 0);
+                assert(rnode.getPresentCongestionCost() == 1);
             }
         }
     }
@@ -1203,11 +1207,11 @@ private void routeConnection(Connection connection) {
             assert(queue.isEmpty());
             // Clears previous route of the connection
             connection.resetRoute();
+            assert(connection.getRnodes().isEmpty());
             assert(!connection.getSink().isRouted());
         }
 
         routingGraph.resetExpansion();
-        assert(!connection.getSinkRnode().isVisited());
     }
 
     /**
@@ -1301,8 +1305,7 @@ private void saveRouting(Connection connection, RouteNode rnode) {
         connection.resetRoute();
         do {
             connection.addRnode(rnode);
-            rnode = rnode.getPrev();
-        } while (rnode != null);
+        } while ((rnode = rnode.getPrev()) != null);
 
         List<RouteNode> rnodes = connection.getRnodes();
         RouteNode sourceRnode = rnodes.get(rnodes.size()-1);
@@ -1340,7 +1343,7 @@ private void saveRouting(Connection connection, RouteNode rnode) {
     /**
      * Explores children (downhill rnodes) of a rnode for routing a connection and pushes the child into the queue,
      * if it is the target or is an accessible routing resource.
-     * @param rnode The parent rnode popped out from the queue.
+     * @param rnode The rnode popped out from the queue.
      * @param connection The connection that is being routed.
      * @param shareWeight The criticality-aware share weight for a new sharing factor.
      * @param rnodeCostWeight The cost weight of the childRnode
@@ -1460,14 +1463,12 @@ private void evaluateCostAndPush(RouteNode rnode, boolean longParent, RouteNode
 
         int childX = childRnode.getEndTileXCoordinate();
         int childY = childRnode.getEndTileYCoordinate();
-        SitePinInst sink = connection.getSink();
-        Tile sinkTile = sink.getTile();
-        int sinkX = sinkTile.getTileXCoordinate();
-        int sinkY = sinkTile.getTileYCoordinate();
+        RouteNode sinkRnode = connection.getSinkRnode();
+        int sinkX = sinkRnode.getBeginTileXCoordinate();
+        int sinkY = sinkRnode.getBeginTileYCoordinate();
         int deltaX = Math.abs(childX - sinkX);
         int deltaY = Math.abs(childY - sinkY);
         if (connection.isCrossSLR()) {
-            RouteNode sinkRnode = connection.getSinkRnode();
             int deltaSLR = Math.abs(sinkRnode.getSLRIndex() - childRnode.getSLRIndex());
             if (deltaSLR != 0) {
                 // Check for overshooting which occurs when child and sink node are in

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

@@ -46,7 +46,7 @@ public class RapidStreamRoute extends PartialRouter{
     /** Nets with conflicting nodes that should be added to the routing targets */
     protected Set<Net> conflictNets;
     /** A keyword to help recognize the target conflict nets */
-    final private String anchorNameKeyword;
+    private final String anchorNameKeyword;
 
     public RapidStreamRoute(Design design, RWRouteConfig config, String anchorNameKeyword) {
         // FIXME

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

@@ -131,7 +131,7 @@ private void setShortestPathToEachVertex() {
         }
     }
 
-    final private static Comparator<NodeWithDelay> NodeWithDelayComparator = (a, b) -> Float.compare(a.getDelay(), b.getDelay());
+    private static final Comparator<NodeWithDelay> NodeWithDelayComparator = (a, b) -> Float.compare(a.getDelay(), b.getDelay());
 
     static class NodeWithDelay{
         private int id;

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

@@ -106,9 +106,12 @@ public RouteNode(Node node, RouteNodeType type) {
 
     @Override
     public int compareTo(RouteNode that) {
-        // Do not use Float.compare() since it also checks NaN, which we'll assume is unreachable
+        // Do not use Float.compare() since it also compares NaN, which we'll assume is unreachable
         // return Float.compare(this.lowerBoundTotalPathCost, that.lowerBoundTotalPathCost);
-        return (int) Math.signum(this.lowerBoundTotalPathCost - that.lowerBoundTotalPathCost);
+        float signum = Math.signum(this.lowerBoundTotalPathCost - that.lowerBoundTotalPathCost);
+        // Tie break according to larger known cost (thus smaller estimated cost to target)
+        return (int) ((signum != 0) ? signum : Math.signum(that.upstreamPathCost - this.upstreamPathCost));
+
     }
 
     abstract protected RouteNode getOrCreate(Node node, RouteNodeType type);
@@ -227,7 +230,7 @@ public boolean hasMultiDrivers() {
         return RouteNode.capacity < uniqueDriverCount();
     }
 
-    public final static EnumSet<TileTypeEnum> lagunaTileTypes = EnumSet.of(
+    public static final EnumSet<TileTypeEnum> lagunaTileTypes = EnumSet.of(
               TileTypeEnum.LAG_LAG      // UltraScale+
             , TileTypeEnum.LAGUNA_TILE  // UltraScale
     );
@@ -394,6 +397,14 @@ public float getDelay() {
         return 0;
     }
 
+    public short getBeginTileXCoordinate() {
+        return (short) node.getTile().getTileXCoordinate();
+    }
+
+    public short getBeginTileYCoordinate() {
+        return (short) node.getTile().getTileYCoordinate();
+    }
+
     /**
      * Gets the x coordinate of the INT {@link Tile} instance
      * that the associated {@link Node} instance stops at.