[vpr][place] add a link between IOs during initial placement

Author: amin1377

libs/libarchfpga/src/physical_types_util.cpp

@@ -652,6 +652,10 @@ bool is_io_type(t_physical_tile_type_ptr type) {
            || is_output_type(type);
 }
 
+bool is_io_type(t_logical_block_type_ptr logical_block) {
+    return is_io_type(pick_physical_type(logical_block));
+}
+
 std::string block_type_pin_index_to_name(t_physical_tile_type_ptr type, int pin_physical_num, bool is_flat) {
     int max_ptc = get_tile_pin_max_ptc(type, is_flat);
     VTR_ASSERT(pin_physical_num < max_ptc);

libs/libarchfpga/src/physical_types_util.h

@@ -126,6 +126,7 @@ bool is_input_type(t_physical_tile_type_ptr type);
 bool is_output_type(t_physical_tile_type_ptr type);
 ///@brief Returns true if the given physical tile type can implement either a .input or .output block type
 bool is_io_type(t_physical_tile_type_ptr type);
+bool is_io_type(t_logical_block_type_ptr logical_block);
 
 /**
  * @brief Returns the corresponding physical pin based on the input parameters:

vpr/src/place/initial_placement.cpp

@@ -472,6 +472,7 @@ static std::vector<ClusterBlockId> find_centroid_loc(const t_pl_macro& pl_macro,
         find_layer = true;
     }
     std::vector<ClusterBlockId> connected_blocks_to_update;
+    std::unordered_set<ClusterBlockId> seen_blocks;
 
     //iterate over the from block pins
     for (ClusterPinId pin_id : cluster_ctx.clb_nlist.block_pins(head_blk)) {
@@ -510,6 +511,7 @@ static std::vector<ClusterBlockId> find_centroid_loc(const t_pl_macro& pl_macro,
                     VTR_ASSERT(tile_loc.layer_num != OPEN);
                     layer_count[tile_loc.layer_num]++;
                 }
+                seen_blocks.insert(cluster_ctx.clb_nlist.pin_block(sink_pin_id));
                 acc_x += tile_loc.x;
                 acc_y += tile_loc.y;
                 acc_weight++;
@@ -530,12 +532,31 @@ static std::vector<ClusterBlockId> find_centroid_loc(const t_pl_macro& pl_macro,
                 VTR_ASSERT(tile_loc.layer_num != OPEN);
                 layer_count[tile_loc.layer_num]++;
             }
+            seen_blocks.insert(cluster_ctx.clb_nlist.pin_block(source_pin));
             acc_x += tile_loc.x;
             acc_y += tile_loc.y;
             acc_weight++;
         }
     }
 
+    if (is_io_type(cluster_ctx.clb_nlist.block_type(head_blk)) && acc_weight != 0) {
+        for (const auto& block : cluster_ctx.clb_nlist.blocks()) {
+            if (seen_blocks.find(block) == seen_blocks.end()) {
+                continue;
+            }
+            if (block == head_blk) {
+                continue;
+            }
+            if (is_io_type(cluster_ctx.clb_nlist.block_type(block))) {
+                if (is_block_placed(block, block_locs)) {
+                    acc_x += block_locs[block].loc.x;
+                    acc_y += block_locs[block].loc.y;
+                    acc_weight++;
+                }
+            }
+        }
+    }
+
     //Calculate the centroid location
     if (acc_weight > 0) {
         centroid.x = acc_x / acc_weight;