removing rr_graph indexed data computation dependency on lookahead type

Author: ArashAhmadian

vpr/src/route/rr_graph.cpp

@@ -260,8 +260,7 @@ static void rr_graph_externals(const std::vector<t_segment_inf>& segment_inf,
                                const std::vector<t_segment_inf>& segment_inf_x,
                                const std::vector<t_segment_inf>& segment_inf_y,
                                int wire_to_rr_ipin_switch,
-                               enum e_base_cost_type base_cost_type,
-                               const enum e_router_lookahead lookahead_type);
+                               enum e_base_cost_type base_cost_type);
 
 static t_clb_to_clb_directs* alloc_and_load_clb_to_clb_directs(const t_direct_inf* directs, const int num_directs, const int delayless_switch);
 
@@ -299,7 +298,6 @@ static void build_rr_graph(const t_graph_type graph_type,
                            const float R_minW_pmos,
                            const enum e_base_cost_type base_cost_type,
                            const enum e_clock_modeling clock_modeling,
-                           const enum e_router_lookahead lookahead_type,
                            const t_direct_inf* directs,
                            const int num_directs,
                            int* wire_to_rr_ipin_switch,
@@ -362,7 +360,6 @@ void create_rr_graph(const t_graph_type graph_type,
                        det_routing_arch->R_minW_pmos,
                        router_opts.base_cost_type,
                        router_opts.clock_modeling,
-                       router_opts.lookahead_type,
                        directs, num_directs,
                        &det_routing_arch->wire_to_rr_ipin_switch,
                        Warnings);
@@ -429,7 +426,6 @@ static void build_rr_graph(const t_graph_type graph_type,
                            const float R_minW_pmos,
                            const enum e_base_cost_type base_cost_type,
                            const enum e_clock_modeling clock_modeling,
-                           const enum e_router_lookahead lookahead_type,
                            const t_direct_inf* directs,
                            const int num_directs,
                            int* wire_to_rr_ipin_switch,
@@ -834,7 +830,7 @@ static void build_rr_graph(const t_graph_type graph_type,
     //Save the channel widths for the newly constructed graph
     device_ctx.chan_width = nodes_per_chan;
 
-    rr_graph_externals(segment_inf, segment_inf_x, segment_inf_y, *wire_to_rr_ipin_switch, base_cost_type, lookahead_type);
+    rr_graph_externals(segment_inf, segment_inf_x, segment_inf_y, *wire_to_rr_ipin_switch, base_cost_type);
 
     check_rr_graph(graph_type, grid, types);
 
@@ -1041,13 +1037,12 @@ static void rr_graph_externals(const std::vector<t_segment_inf>& segment_inf,
                                const std::vector<t_segment_inf>& segment_inf_x,
                                const std::vector<t_segment_inf>& segment_inf_y,
                                int wire_to_rr_ipin_switch,
-                               enum e_base_cost_type base_cost_type,
-                               const enum e_router_lookahead lookahead_type) {
+                               enum e_base_cost_type base_cost_type) {
     auto& device_ctx = g_vpr_ctx.device();
     const auto& rr_graph = device_ctx.rr_graph;
     add_rr_graph_C_from_switches(rr_graph.rr_switch_inf(RRSwitchId(wire_to_rr_ipin_switch)).Cin);
     alloc_and_load_rr_indexed_data(segment_inf, segment_inf_x,
-                                   segment_inf_y, wire_to_rr_ipin_switch, base_cost_type, lookahead_type);
+                                   segment_inf_y, wire_to_rr_ipin_switch, base_cost_type);
     //load_rr_index_segments(segment_inf.size());
 }
 

vpr/src/route/rr_graph_indexed_data.cpp

@@ -58,8 +58,7 @@ void alloc_and_load_rr_indexed_data(const std::vector<t_segment_inf>& segment_in
                                     const std::vector<t_segment_inf>& segment_inf_x,
                                     const std::vector<t_segment_inf>& segment_inf_y,
                                     int wire_to_ipin_switch,
-                                    enum e_base_cost_type base_cost_type,
-                                    enum e_router_lookahead lookahed_type) {
+                                    enum e_base_cost_type base_cost_type) {
     int length, i, index;
 
     (void)segment_inf;
@@ -87,19 +86,24 @@ void alloc_and_load_rr_indexed_data(const std::vector<t_segment_inf>& segment_in
     }
     device_ctx.rr_indexed_data[RRIndexedDataId(IPIN_COST_INDEX)].T_linear = rr_graph.rr_switch_inf(RRSwitchId(wire_to_ipin_switch)).Tdel;
 
-    /* X-directed segments*/
     std::vector<int> ortho_costs;
 
-    if (lookahed_type == e_router_lookahead::CLASSIC) {
-        ortho_costs = find_ortho_cost_index(segment_inf_x, segment_inf_y, X_AXIS);
+    ortho_costs = find_ortho_cost_index(segment_inf_x, segment_inf_y, X_AXIS);
 
-    } else {
-        std::vector<int> x_costs(segment_inf_x.size(), CHANX_COST_INDEX_START + segment_inf_x.size());
-        std::vector<int> y_costs(segment_inf_y.size(), CHANX_COST_INDEX_START);
+    /* AA: The code below should replace find_ortho_cost_index call once we deprecate the CLASSIC lookahead as it is the only lookahead
+        * that actively uses the orthogonal cost indices. To avoid complicated dependencies with the rr_graph reader, regardless of the lookahead,
+        * we walk to the rr_graph edges to get these indices. */
+    /*
+
+    std::vector<int> x_costs(segment_inf_x.size(), CHANX_COST_INDEX_START + segment_inf_x.size());
+    std::vector<int> y_costs(segment_inf_y.size(), CHANX_COST_INDEX_START);
+
+    std::move(x_costs.begin(), x_costs.end(), std::back_inserter(ortho_costs));
+    std::move(y_costs.begin(), y_costs.end(), std::back_inserter(ortho_costs));
+    */
+    
+    /* X-directed segments*/
 
-        std::move(x_costs.begin(), x_costs.end(), std::back_inserter(ortho_costs));
-        std::move(y_costs.begin(), y_costs.end(), std::back_inserter(ortho_costs));
-    }
     for (size_t iseg = 0; iseg < segment_inf_x.size(); ++iseg) {
         index = iseg + CHANX_COST_INDEX_START;
 
@@ -116,7 +120,7 @@ void alloc_and_load_rr_indexed_data(const std::vector<t_segment_inf>& segment_in
         device_ctx.rr_indexed_data[RRIndexedDataId(index)].seg_index = segment_inf_x[iseg].seg_index;
     }
 
-    // Y-directed segments
+    /* Y-directed segments*/
 
     for (size_t iseg = segment_inf_x.size(); iseg < ortho_costs.size(); ++iseg) {
         index = iseg + CHANX_COST_INDEX_START;

vpr/src/route/rr_graph_indexed_data.h

@@ -6,8 +6,7 @@ void alloc_and_load_rr_indexed_data(const std::vector<t_segment_inf>& segment_in
                                     const std::vector<t_segment_inf>& segment_inf_x,
                                     const std::vector<t_segment_inf>& segment_inf_y,
                                     int wire_to_ipin_switch,
-                                    enum e_base_cost_type base_cost_type,
-                                    const enum e_router_lookahead lookahead_type);
+                                    enum e_base_cost_type base_cost_type);
 
 void load_rr_index_segments(const int num_segment);
 

vpr/src/route/rr_graph_uxsdcxx_serializer.h

@@ -1568,15 +1568,13 @@ class RrGraphSerializer final : public uxsd::RrGraphBase<RrGraphContextTypes> {
         auto segment_inf_x_ = get_parallel_segs(temp_rr_segs, seg_index_map, X_AXIS);
         auto segment_inf_y_ = get_parallel_segs(temp_rr_segs, seg_index_map, Y_AXIS);
 
-        /*AA: e_router_lookahead::DONT_CARE is used as a place holder. The lookahead type only has control over the orthocost indeces vector 
-         * which is only relevant to the classic lookahead. */
+
         alloc_and_load_rr_indexed_data(
             temp_rr_segs,
             segment_inf_x_,
             segment_inf_y_,
             *wire_to_rr_ipin_switch_,
-            base_cost_type_,
-            e_router_lookahead::DONT_CARE);
+            base_cost_type_);
 
         VTR_ASSERT(rr_indexed_data_->size() == seg_index_.size());
         for (size_t i = 0; i < seg_index_.size(); ++i) {