[VPR] Add a new API find_nodes_at_all_sides() to RRSpatialLookup

Author: tangxifan

vpr/src/device/rr_spatial_lookup.cpp

@@ -130,6 +130,32 @@ std::vector<RRNodeId> RRSpatialLookup::find_channel_nodes(int x,
     return channel_nodes;
 }
 
+std::vector<RRNodeId> RRSpatialLookup::find_nodes_at_all_sides(int x,
+                                                               int y,
+                                                               t_rr_type rr_type,
+                                                               int ptc) const {
+    std::vector<RRNodeId> indices;
+
+    /* TODO: Consider to access the raw data like find_node() rather than calling find_node() many times, which hurts runtime */
+    if (rr_type == IPIN || rr_type == OPIN) {
+        //For pins we need to look at all the sides of the current grid tile
+        for (e_side side : SIDES) {
+            RRNodeId rr_node_index = find_node(x, y, rr_type, ptc, side);
+            if (rr_node_index) {
+                indices.push_back(rr_node_index);
+            }
+        }
+    } else {
+        //Sides do not effect non-pins so there should only be one per ptc
+        RRNodeId rr_node_index = find_node(x, y, rr_type, ptc);
+        if (rr_node_index) {
+            indices.push_back(rr_node_index);
+        }
+    }
+
+    return indices;
+}
+
 void RRSpatialLookup::add_node(RRNodeId node,
                                int x,
                                int y,

vpr/src/device/rr_spatial_lookup.h

@@ -80,6 +80,16 @@ class RRSpatialLookup {
                                              int y,
                                              t_rr_type type) const;
 
+    /**
+     * Like find_node() but returns all matching nodes on all the sides.
+     * This is particularly useful for getting all instances
+     * of a specific IPIN/OPIN at a specific gird tile (x,y) location.
+     */
+    std::vector<RRNodeId> find_nodes_at_all_sides(int x,
+                                                  int y,
+                                                  t_rr_type rr_type,
+                                                  int ptc) const;
+
     /* -- Mutators -- */
   public:
     /**