Merge pull request #2639 from nedsels/improve_map_lookahead

Improve SINK Node Locations

Author: vaughnbetz

doc/src/api/vpr/grid.rst

@@ -0,0 +1,10 @@
+========
+Grid
+========
+
+DeviceGrid
+-------
+
+.. doxygenclass:: DeviceGrid
+   :project: vpr
+   :members:

doc/src/api/vpr/index.rst

@@ -7,6 +7,7 @@ VPR API
    :maxdepth: 1
 
    contexts
+   grid
    mapping
    netlist
    route_tree

doc/src/api/vpr/rr_graph.rst

@@ -35,3 +35,9 @@ RRSpatialLookup
    :project: librrgraph
    :members:
 
+rr_graph_utils
+---------------
+
+.. doxygenfile:: rr_graph_utils.h
+   :project: librrgraph
+   :sections: briefdescription detaileddescription func prototype user-defined public-func

doc/src/api/vprinternals/router_lookahead.rst

@@ -0,0 +1,35 @@
+==============
+Router Lookahead
+==============
+
+e_router_lookahead
+----------
+.. doxygenenum:: e_router_lookahead
+   :project: vpr
+
+
+RouterLookahead
+----------
+.. doxygenclass:: RouterLookahead
+   :project: vpr
+   :members:
+
+MapLookahead
+----------
+.. doxygenclass:: MapLookahead
+   :project: vpr
+
+make_router_lookahead
+----------
+.. doxygenfunction:: make_router_lookahead
+   :project: vpr
+
+get_cached_router_lookahead
+----------
+.. doxygenfunction:: get_cached_router_lookahead
+   :project: vpr
+
+invalidate_router_lookahead_cache
+----------
+.. doxygenfunction:: invalidate_router_lookahead_cache
+   :project: vpr

doc/src/api/vprinternals/vpr_router.rst

@@ -7,4 +7,5 @@ VPR Router
 .. toctree::
    :maxdepth: 1
 
-   router_heap
+   router_heap
+   router_lookahead

libs/libarchfpga/src/device_grid.h

@@ -6,6 +6,7 @@
 #include <cmath>
 #include "vtr_ndmatrix.h"
 #include "physical_types.h"
+#include "vtr_geometry.h"
 
 /**
  * @brief s_grid_tile is the minimum tile of the fpga
@@ -73,6 +74,18 @@ class DeviceGrid {
         return grid_[tile_loc.layer_num][tile_loc.x][tile_loc.y].height_offset;
     }
 
+    ///@brief Returns a rectangle which represents the bounding box of the tile at the given location.
+    inline vtr::Rect<int> get_tile_bb(const t_physical_tile_loc& tile_loc) const {
+        t_physical_tile_type_ptr tile_type = get_physical_type(tile_loc);
+
+        int tile_xlow = tile_loc.x - get_width_offset(tile_loc);
+        int tile_ylow = tile_loc.y - get_height_offset(tile_loc);
+        int tile_xhigh = tile_xlow + tile_type->width - 1;
+        int tile_yhigh = tile_ylow + tile_type->height - 1;
+
+        return {{tile_xlow, tile_ylow}, {tile_xhigh, tile_yhigh}};
+    }
+
     ///@brief Return the metadata of the tile at the specified location
     inline const t_metadata_dict* get_metadata(const t_physical_tile_loc& tile_loc) const {
         return grid_[tile_loc.layer_num][tile_loc.x][tile_loc.y].meta;

libs/librrgraph/src/base/check_rr_graph.cpp

@@ -9,6 +9,7 @@
 #include "physical_types_util.h"
 
 #include "describe_rr_node.h"
+#include "rr_graph_utils.h"
 
 /*********************** Subroutines local to this module *******************/
 
@@ -389,16 +390,29 @@ void check_rr_node(const RRGraphView& rr_graph,
 
     switch (rr_type) {
         case SOURCE:
-        case SINK:
             if (type == nullptr) {
                 VPR_FATAL_ERROR(VPR_ERROR_ROUTE,
                                 "in check_rr_node: node %d (type %d) is at an illegal clb location (%d, %d).\n", inode, rr_type, xlow, ylow);
             }
+
             if (xlow != (xhigh - type->width + 1) || ylow != (yhigh - type->height + 1)) {
                 VPR_FATAL_ERROR(VPR_ERROR_ROUTE,
                                 "in check_rr_node: node %d (type %d) has endpoints (%d,%d) and (%d,%d)\n", inode, rr_type, xlow, ylow, xhigh, yhigh);
             }
             break;
+        case SINK: {
+            if (type == nullptr) {
+                VPR_FATAL_ERROR(VPR_ERROR_ROUTE,
+                                "in check_rr_node: node %d (type %d) is at an illegal clb location (%d, %d).\n", inode, rr_type, xlow, ylow);
+            }
+
+            vtr::Rect<int> tile_bb = grid.get_tile_bb({xlow, ylow, layer_num});
+            if (xlow < tile_bb.xmin() || ylow < tile_bb.ymin() || xhigh > tile_bb.xmax() || yhigh > tile_bb.ymax()) {
+                VPR_FATAL_ERROR(VPR_ERROR_ROUTE,
+                                "in check_rr_node: node %d (type %d) has endpoints (%d,%d) and (%d,%d), which is outside the bounds of the grid tile containing it.\n", inode, rr_type, xlow, ylow, xhigh, yhigh);
+            }
+            break;
+        }
         case IPIN:
         case OPIN:
             if (type == nullptr) {

libs/librrgraph/src/base/rr_graph_utils.cpp

@@ -1,21 +1,60 @@
-
-/****************************************************************************
- * This file include most-utilized functions that manipulate on the
- * RRGraph object
- ***************************************************************************/
 #include <queue>
 #include <random>
 
 #include "rr_graph_utils.h"
-
 #include "vpr_error.h"
-
 #include "rr_graph_obj.h"
+#include "rr_graph_builder.h"
+
+/*
+ * @brief Walk backwards from origin SINK, and insert all cluster-edge IPINs to which origin is connected to sink_ipins
+ *
+ * @param rr_graph
+ * @param fanins A vector where, at each node index, is a vector of edges which are fanins of that node
+ * @param sink_ipins The set in which cluster-edge IPINs will be collected; should be empty
+ * @param curr The current node in recursion; originally, should be the same as origin
+ * @param origin The SINK whose cluster-edge IPINs are to be collected
+ */
+static void rr_walk_cluster_recursive(const RRGraphView& rr_graph,
+                                      const vtr::vector<RRNodeId, std::vector<RREdgeId>>& fanins,
+                                      std::unordered_set<RRNodeId>& sink_ipins,
+                                      const RRNodeId curr,
+                                      const RRNodeId origin);
+
+static void rr_walk_cluster_recursive(const RRGraphView& rr_graph,
+                                      const vtr::vector<RRNodeId, std::vector<RREdgeId>>& fanins,
+                                   std::unordered_set<RRNodeId>& sink_ipins,
+                                   const RRNodeId curr,
+                                   const RRNodeId origin) {
+    // Make sure SINK in the same cluster as origin
+    int curr_x = rr_graph.node_xlow(curr);
+    int curr_y = rr_graph.node_ylow(curr);
+    if ((curr_x < rr_graph.node_xlow(origin)) || (curr_x > rr_graph.node_xhigh(origin)) || (curr_y < rr_graph.node_ylow(origin)) || (curr_y > rr_graph.node_yhigh(origin)))
+        return;
+
+    VTR_ASSERT_SAFE(rr_graph.node_type(origin) == e_rr_type::SINK);
+
+    // We want to go "backward" to the cluster IPINs connected to the origin node
+    const std::vector<RREdgeId>& incoming_edges = fanins[curr];
+    for (RREdgeId edge : incoming_edges) {
+        RRNodeId parent = rr_graph.edge_src_node(edge);
+        VTR_ASSERT_SAFE(parent != RRNodeId::INVALID());
+
+        if (rr_graph.node_type(parent) != e_rr_type::IPIN) {
+            if (rr_graph.node_type(parent) != e_rr_type::CHANX && rr_graph.node_type(parent) != e_rr_type::CHANY)
+                return;
+
+            // If the parent node isn't in the origin's cluster, the current node is a "cluster-edge" pin,
+            // so add it to sink_ipins
+            sink_ipins.insert(curr);
+            return;
+        }
+
+        // If the parent node is intra-cluster, keep going "backward"
+        rr_walk_cluster_recursive(rr_graph, fanins, sink_ipins, parent, origin);
+    }
+}
 
-/****************************************************************************
- * Find the switches interconnecting two nodes
- * Return a vector of switch ids
- ***************************************************************************/
 std::vector<RRSwitchId> find_rr_graph_switches(const RRGraph& rr_graph,
                                                const RRNodeId& from_node,
                                                const RRNodeId& to_node) {
@@ -37,9 +76,6 @@ std::vector<RRSwitchId> find_rr_graph_switches(const RRGraph& rr_graph,
 }
 
 int seg_index_of_cblock(const RRGraphView& rr_graph, t_rr_type from_rr_type, int to_node) {
-    /* Returns the segment number (distance along the channel) of the connection *
-     * box from from_rr_type (CHANX or CHANY) to to_node (IPIN).                 */
-
     if (from_rr_type == CHANX)
         return (rr_graph.node_xlow(RRNodeId(to_node)));
     else
@@ -48,13 +84,6 @@ int seg_index_of_cblock(const RRGraphView& rr_graph, t_rr_type from_rr_type, int
 }
 
 int seg_index_of_sblock(const RRGraphView& rr_graph, int from_node, int to_node) {
-    /* Returns the segment number (distance along the channel) of the switch box *
-     * box from from_node (CHANX or CHANY) to to_node (CHANX or CHANY).  The     *
-     * switch box on the left side of a CHANX segment at (i,j) has seg_index =   *
-     * i-1, while the switch box on the right side of that segment has seg_index *
-     * = i.  CHANY stuff works similarly.  Hence the range of values returned is *
-     * 0 to device_ctx.grid.width()-1 (if from_node is a CHANX) or 0 to device_ctx.grid.height()-1 (if from_node is a CHANY).   */
-
     t_rr_type from_rr_type, to_rr_type;
 
     from_rr_type = rr_graph.node_type(RRNodeId(from_node));
@@ -117,6 +146,97 @@ vtr::vector<RRNodeId, std::vector<RREdgeId>> get_fan_in_list(const RRGraphView&
     return node_fan_in_list;
 }
 
+void rr_set_sink_locs(const RRGraphView& rr_graph, RRGraphBuilder& rr_graph_builder, const DeviceGrid& grid) {
+    const vtr::vector<RRNodeId, std::vector<RREdgeId>> node_fanins = get_fan_in_list(rr_graph);
+
+    // Keep track of offsets for SINKs for each tile type, to avoid repeated calculations
+    std::unordered_map<t_physical_tile_type_ptr, std::unordered_map<int, vtr::Point<int>>> physical_type_offsets;
+
+    // Iterate over all SINK nodes
+    for (size_t node = 0; node < rr_graph.num_nodes(); ++node) {
+        auto node_id = RRNodeId(node);
+
+        if (rr_graph.node_type((RRNodeId)node_id) != e_rr_type::SINK)
+            continue;
+
+        int node_xlow = rr_graph.node_xlow(node_id);
+        int node_ylow = rr_graph.node_ylow(node_id);
+        int node_xhigh = rr_graph.node_xhigh(node_id);
+        int node_yhigh = rr_graph.node_yhigh(node_id);
+
+        // Skip "0x0" nodes; either the tile is 1x1, or we have seen the node on a previous call of this function
+        // and its new location has already been set
+        if ((node_xhigh - node_xlow) == 0 && (node_yhigh - node_ylow) == 0)
+            continue;
+
+        int node_layer = rr_graph.node_layer(node_id);
+        int node_ptc = rr_graph.node_ptc_num(node_id);
+
+        t_physical_tile_loc tile_loc = {node_xlow, node_ylow, node_layer};
+        t_physical_tile_type_ptr tile_type = grid.get_physical_type(tile_loc);
+        vtr::Rect<int> tile_bb = grid.get_tile_bb(tile_loc);
+
+        // See if we have encountered this tile type/ptc combo before, and used saved offset if so
+        vtr::Point<int> new_loc(-1, -1);
+        if ((physical_type_offsets.find(tile_type) != physical_type_offsets.end()) && (physical_type_offsets[tile_type].find(node_ptc) != physical_type_offsets[tile_type].end())) {
+            new_loc = tile_bb.bottom_left() + physical_type_offsets[tile_type].at(node_ptc);
+        } else { /* We have not seen this tile type/ptc combo before */
+            // The IPINs of the current SINK node
+            std::unordered_set<RRNodeId> sink_ipins = {};
+            rr_walk_cluster_recursive(rr_graph, node_fanins, sink_ipins, node_id, node_id);
+
+            /* Set SINK locations as average of collected IPINs */
+
+            if (sink_ipins.empty())
+                continue;
+
+            // Use float so that we can take average later
+            std::vector<float> x_coords;
+            std::vector<float> y_coords;
+
+            // Add coordinates of each "cluster-edge" pin to vectors
+            for (const auto& pin : sink_ipins) {
+                int pin_x = rr_graph.node_xlow(pin);
+                int pin_y = rr_graph.node_ylow(pin);
+
+                VTR_ASSERT_SAFE(pin_x == rr_graph.node_xhigh(pin));
+                VTR_ASSERT_SAFE(pin_y == rr_graph.node_yhigh(pin));
+
+                x_coords.push_back((float)pin_x);
+                y_coords.push_back((float)pin_y);
+            }
+
+            new_loc = {(int)round(std::accumulate(x_coords.begin(), x_coords.end(), 0.f) / (double)x_coords.size()),
+                       (int)round(std::accumulate(y_coords.begin(), y_coords.end(), 0.f) / (double)y_coords.size())};
+
+            // Save offset for this tile/ptc combo
+            if (physical_type_offsets.find(tile_type) == physical_type_offsets.end())
+                physical_type_offsets[tile_type] = {};
+
+            physical_type_offsets[tile_type].insert({node_ptc, new_loc - tile_bb.bottom_left()});
+        }
+
+        // Remove old locations from lookup
+        VTR_ASSERT(rr_graph_builder.node_lookup().find_node(node_layer, new_loc.x(), new_loc.y(), SINK, node_ptc) != RRNodeId::INVALID());
+
+        for (int x = tile_bb.xmin(); x <= tile_bb.xmax(); ++x) {
+            for (int y = tile_bb.ymin(); y <= tile_bb.ymax(); ++y) {
+                if (x == new_loc.x() && y == new_loc.y()) /* The new sink location */
+                    continue;
+
+                if (rr_graph_builder.node_lookup().find_node(node_layer, x, y, SINK, node_ptc) == RRNodeId::INVALID()) /* Already removed */
+                    continue;
+
+                bool removed_successfully = rr_graph_builder.node_lookup().remove_node(node_id, node_layer, x, y, SINK, node_ptc);
+                VTR_ASSERT(removed_successfully);
+            }
+        }
+
+        // Set new coordinates
+        rr_graph_builder.set_node_coordinates(node_id, (short)new_loc.x(), (short)new_loc.y(), (short)new_loc.x(), (short)new_loc.y());
+    }
+}
+
 bool inter_layer_connections_limited_to_opin(const RRGraphView& rr_graph) {
     bool limited_to_opin = true;
     for (const auto& from_node : rr_graph.nodes()) {