clip HF BB by original BB

Author: duck2

vpr/src/route/connection_router.cpp

@@ -964,16 +964,21 @@ void ConnectionRouter<Heap>::add_route_tree_node_to_heap(
     }
 }
 
-static t_bb adjust_highfanout_bounding_box(t_bb highfanout_bb) {
-    t_bb bb = highfanout_bb;
+/* Expand bb by inode's extents and clip against net_bb */
+inline void expand_highfanout_bounding_box(t_bb& bb, const t_bb& net_bb, RRNodeId inode, const RRGraphView* rr_graph) {
+    bb.xmin = std::max<int>(net_bb.xmin, std::min<int>(bb.xmin, rr_graph->node_xlow(inode)));
+    bb.ymin = std::max<int>(net_bb.ymin, std::min<int>(bb.ymin, rr_graph->node_ylow(inode)));
+    bb.xmax = std::min<int>(net_bb.xmax, std::max<int>(bb.xmax, rr_graph->node_xhigh(inode)));
+    bb.ymax = std::min<int>(net_bb.ymax, std::max<int>(bb.ymax, rr_graph->node_yhigh(inode)));
+}
 
+/* Expand bb by HIGH_FANOUT_BB_FAC and clip against net_bb */
+inline void adjust_highfanout_bounding_box(t_bb& bb, const t_bb& net_bb) {
     constexpr int HIGH_FANOUT_BB_FAC = 3;
-    bb.xmin -= HIGH_FANOUT_BB_FAC;
-    bb.ymin -= HIGH_FANOUT_BB_FAC;
-    bb.xmax += HIGH_FANOUT_BB_FAC;
-    bb.ymax += HIGH_FANOUT_BB_FAC;
-
-    return bb;
+    bb.xmin = std::max<int>(net_bb.xmin, bb.xmin - HIGH_FANOUT_BB_FAC);
+    bb.ymin = std::max<int>(net_bb.ymin, bb.ymin - HIGH_FANOUT_BB_FAC);
+    bb.xmax = std::min<int>(net_bb.xmax, bb.xmax + HIGH_FANOUT_BB_FAC);
+    bb.ymax = std::min<int>(net_bb.ymax, bb.ymax + HIGH_FANOUT_BB_FAC);
 }
 
 template<typename Heap>
@@ -1032,11 +1037,8 @@ t_bb ConnectionRouter<Heap>::add_high_fanout_route_tree_to_heap(
                 // Put the node onto the heap
                 add_route_tree_node_to_heap(rt_node, target_node, cost_params, true);
 
-                // Update Bounding Box
-                highfanout_bb.xmin = std::min<int>(highfanout_bb.xmin, rr_graph_->node_xlow(rr_node_to_add));
-                highfanout_bb.ymin = std::min<int>(highfanout_bb.ymin, rr_graph_->node_ylow(rr_node_to_add));
-                highfanout_bb.xmax = std::max<int>(highfanout_bb.xmax, rr_graph_->node_xhigh(rr_node_to_add));
-                highfanout_bb.ymax = std::max<int>(highfanout_bb.ymax, rr_graph_->node_yhigh(rr_node_to_add));
+                // Expand HF BB to include the node (clip by original BB)
+                expand_highfanout_bounding_box(highfanout_bb, net_bounding_box, rr_node_to_add, rr_graph_);
                 if (is_flat_) {
                     if (rr_graph_->node_type(rr_node_to_add) == CHANY || rr_graph_->node_type(rr_node_to_add) == CHANX) {
                         chan_nodes_added++;
@@ -1062,15 +1064,14 @@ t_bb ConnectionRouter<Heap>::add_high_fanout_route_tree_to_heap(
         if (done) break;
     }
 
-    t_bb bounding_box = net_bounding_box;
     if (nodes_added == 0) { //If the target bin, and it's surrounding bins were empty, just add the full route tree
         add_route_tree_to_heap(rt_root, target_node, cost_params, true);
+        return net_bounding_box;
     } else {
         //We found nearby routing, replace original bounding box to be localized around that routing
-        bounding_box = adjust_highfanout_bounding_box(highfanout_bb);
+        adjust_highfanout_bounding_box(highfanout_bb, net_bounding_box);
+        return highfanout_bb;
     }
-
-    return bounding_box;
 }
 
 std::unique_ptr<ConnectionRouterInterface> make_connection_router(e_heap_type heap_type,

vpr/test/test_connection_router.cpp

@@ -1,6 +1,7 @@
 #include <tuple>
 #include "catch2/catch_test_macros.hpp"
 
+#include "route_net.h"
 #include "rr_graph_fwd.h"
 #include "vpr_api.h"
 #include "vpr_signal_handler.h"
@@ -73,8 +74,7 @@ static float do_one_route(RRNodeId source_node,
                                                                                                         cost_params,
                                                                                                         bounding_box,
                                                                                                         router_stats,
-                                                                                                        conn_params,
-                                                                                                        true);
+                                                                                                        conn_params);
 
     // Default delay is infinity, which indicates that a route was not found.
     float delay = std::numeric_limits<float>::infinity();