Make pathfinder aware of the arch-specific routing constraints (#657)

Xilinx · Sep 26, 2023 · 9236591 · 9236591
1 parent cb25fae
commit 9236591
Show file tree

Hide file tree

Showing 3 changed files with 32 additions and 19 deletions.
diff --git a/include/aie/Dialect/AIE/Transforms/AIEPathfinder.h b/include/aie/Dialect/AIE/Transforms/AIEPathfinder.h
@@ -81,8 +81,8 @@ class Pathfinder {
 
 public:
   Pathfinder();
-  Pathfinder(int maxcol, int maxrow);
-  void initializeGraph(int maxcol, int maxrow);
+  Pathfinder(int maxcol, int maxrow, DeviceOp &d);
+  void initializeGraph(int maxcol, int maxrow, DeviceOp &d);
   void addFlow(Coord srcCoords, Port srcPort, Coord dstCoords, Port dstPort);
   void addFixedConnection(Coord coord, Port port);
   bool isLegal();

diff --git a/lib/Dialect/AIE/Transforms/AIECreatePathfindFlows.cpp b/lib/Dialect/AIE/Transforms/AIECreatePathfindFlows.cpp
@@ -119,7 +119,7 @@ class DynamicTileAnalysis {
       maxrow = std::max(maxrow, tileOp.rowIndex());
     }
 
-    pathfinder = Pathfinder(maxcol, maxrow);
+    pathfinder = Pathfinder(maxcol, maxrow, d);
 
     // for each flow in the device, add it to pathfinder
     // each source can map to multiple different destinations (fanout)

diff --git a/lib/Dialect/AIE/Transforms/AIEPathfinder.cpp b/lib/Dialect/AIE/Transforms/AIEPathfinder.cpp
@@ -38,13 +38,14 @@ WireBundle getConnectingBundle(WireBundle dir) {
   }
 }
 
-Pathfinder::Pathfinder() { initializeGraph(0, 0); }
+Pathfinder::Pathfinder() {}
 
-Pathfinder::Pathfinder(int _maxcol, int _maxrow) {
-  initializeGraph(_maxcol, _maxrow);
+Pathfinder::Pathfinder(int _maxcol, int _maxrow, DeviceOp &d) {
+  initializeGraph(_maxcol, _maxrow, d);
 }
 
-void Pathfinder::initializeGraph(int maxcol, int maxrow) {
+void Pathfinder::initializeGraph(int maxcol, int maxrow, DeviceOp &d) {
+  const auto &targetModel = d.getTargetModel();
   // make grid of switchboxes
   for (int row = 0; row <= maxrow; row++) {
     for (int col = 0; col <= maxcol; col++) {
@@ -54,20 +55,32 @@ void Pathfinder::initializeGraph(int maxcol, int maxrow) {
       graph[id].pred = 0;
       graph[id].processed = false;
       if (row > 0) { // if not in row 0 add channel to North/South
-        auto north_edge = add_edge(id - maxcol - 1, id, graph).first;
-        graph[north_edge].bundle = WireBundle::North;
-        graph[north_edge].max_capacity = 6;
-        auto south_edge = add_edge(id, id - maxcol - 1, graph).first;
-        graph[south_edge].bundle = WireBundle::South;
-        graph[south_edge].max_capacity = 4;
+        if (auto max_capacity = targetModel.getNumSourceSwitchboxConnections(
+                col, row, WireBundle::South)) {
+          auto north_edge = add_edge(id - maxcol - 1, id, graph).first;
+          graph[north_edge].bundle = WireBundle::North;
+          graph[north_edge].max_capacity = max_capacity;
+        }
+        if (auto max_capacity = targetModel.getNumDestSwitchboxConnections(
+                col, row, WireBundle::South)) {
+          auto south_edge = add_edge(id, id - maxcol - 1, graph).first;
+          graph[south_edge].bundle = WireBundle::South;
+          graph[south_edge].max_capacity = max_capacity;
+        }
       }
       if (col > 0) { // if not in col 0 add channel to East/West
-        auto east_edge = add_edge(id - 1, id, graph).first;
-        graph[east_edge].bundle = WireBundle::East;
-        graph[east_edge].max_capacity = 4;
-        auto west_edge = add_edge(id, id - 1, graph).first;
-        graph[west_edge].bundle = WireBundle::West;
-        graph[west_edge].max_capacity = 4;
+        if (auto max_capacity = targetModel.getNumSourceSwitchboxConnections(
+                col, row, WireBundle::West)) {
+          auto east_edge = add_edge(id - 1, id, graph).first;
+          graph[east_edge].bundle = WireBundle::East;
+          graph[east_edge].max_capacity = max_capacity;
+        }
+        if (auto max_capacity = targetModel.getNumDestSwitchboxConnections(
+                col, row, WireBundle::West)) {
+          auto west_edge = add_edge(id, id - 1, graph).first;
+          graph[west_edge].bundle = WireBundle::West;
+          graph[west_edge].max_capacity = max_capacity;
+        }
       }
     }
   }