Merge pull request #2720 from ueqri/ueqri-enhanced-heap-for-connectio…

…n-router

[Router] Enhanced the Connection Router by Optimizing the Heap Structure

.gitignore

@@ -155,3 +155,8 @@ tags
 cmake-build-debug
 cmake-build-release
 /.metadata/
+
+#
+# Clangd
+#
+compile_commands.json

doc/src/api/vpr/route_tree.rst

@@ -20,3 +20,10 @@ RouteTreeNode
 .. doxygenclass:: RouteTreeNode
  :project: vpr
  :members:
+
+RTExploredNode
+-------------
+
+.. doxygenclass:: RTExploredNode
+ :project: vpr
+ :members:

doc/src/api/vprinternals/router_heap.rst

@@ -2,30 +2,13 @@
 Router Heap
 ==============
 
-t_heap
-----------
-.. doxygenstruct:: t_heap
- :project: vpr
- :members:
-
 HeapInterface
 ----------
 .. doxygenclass:: HeapInterface
  :project: vpr
  :members:
 
-HeapStorage
-----------
-.. doxygenclass:: HeapStorage
- :project: vpr
- :members:
-
-KAryHeap
+DAryHeap
 ----------
-.. doxygenclass:: KAryHeap
+.. doxygenclass:: DAryHeap
  :project: vpr
-
-FourAryHeap
-----------
-.. doxygenclass:: FourAryHeap
- :project: vpr

doc/src/vpr/command_line_usage.rst

@@ -1396,15 +1396,17 @@ The following options are only valid when the router is in timing-driven mode (t
 
  **Default:** ``safe``
 
-.. option:: --routing_budgets_algorithm { disable | minimax | scale_delay }
+.. option:: --routing_budgets_algorithm { disable | minimax | yoyo | scale_delay }
 
  .. warning:: Experimental
 
  Controls how the routing budgets are created. Routing budgets are used to guid VPR's routing algorithm to consider both short path and long path timing constraints :cite:`RCV_algorithm`.
 
  ``disable`` is used to disable the budget feature. This uses the default VPR and ignores hold time constraints.
 
- ``minimax`` sets the minimum and maximum budgets by distributing the long path and short path slacks depending on the the current delay values. This uses the routing cost valleys and Minimax-PERT algorithm :cite:`minimax_pert,RCV_algorithm`.
+ ``minimax`` sets the minimum and maximum budgets by distributing the long path and short path slacks depending on the the current delay values. This uses the Minimax-PERT algorithm :cite:`minimax_pert`.
+
+ ``yoyo`` allocates budgets using minimax algorithm (as above), and enables hold slack resolution in the router using the Routing Cost Valleys (RCV) algorithm :cite:`RCV_algorithm`.
 
  ``scale_delay`` has the minimum budgets set to 0 and the maximum budgets is set to the delay of a net scaled by the pin criticality (net delay/pin criticality).
 

utils/route_diag/src/main.cpp

@@ -114,7 +114,7 @@ static void do_one_route(const Netlist<>& net_list,
  is_flat);
  enable_router_debug(router_opts, ParentNetId(), sink_node, 1, &router);
  bool found_path;
- t_heap cheapest;
+ RTExploredNode cheapest;
  ConnectionParameters conn_params(ParentNetId::INVALID(),
  -1,
  false,

vpr/src/base/ShowSetup.cpp

@@ -468,9 +468,6 @@ static void ShowRouterOpts(const t_router_opts& RouterOpts) {
  case e_heap_type::FOUR_ARY_HEAP:
  VTR_LOG("FOUR_ARY_HEAP\n");
  break;
- case e_heap_type::BUCKET_HEAP_APPROXIMATION:
- VTR_LOG("BUCKET_HEAP_APPROXIMATION\n");
- break;
  default:
  VPR_FATAL_ERROR(VPR_ERROR_UNKNOWN, "Unknown router_heap\n");
  }

vpr/src/base/read_options.cpp

@@ -272,7 +272,7 @@ struct RouteBudgetsAlgorithm {
  }
 
  std::vector<std::string> default_choices() {
- return {"minimax", "scale_delay", "disable"};
+ return {"minimax", "yoyo", "scale_delay", "disable"};
  }
 };
 
@@ -1063,8 +1063,6 @@ struct ParseRouterHeap {
  conv_value.set_value(e_heap_type::BINARY_HEAP);
  else if (str == "four_ary")
  conv_value.set_value(e_heap_type::FOUR_ARY_HEAP);
- else if (str == "bucket")
- conv_value.set_value(e_heap_type::BUCKET_HEAP_APPROXIMATION);
  else {
  std::stringstream msg;
  msg << "Invalid conversion from '" << str << "' to e_heap_type (expected one of: " << argparse::join(default_choices(), ", ") << ")";
@@ -1077,11 +1075,9 @@ struct ParseRouterHeap {
  ConvertedValue<std::string> conv_value;
  if (val == e_heap_type::BINARY_HEAP)
  conv_value.set_value("binary");
- else if (val == e_heap_type::FOUR_ARY_HEAP)
- conv_value.set_value("four_ary");
  else {
- VTR_ASSERT(val == e_heap_type::BUCKET_HEAP_APPROXIMATION);
- conv_value.set_value("bucket");
+ VTR_ASSERT(val == e_heap_type::FOUR_ARY_HEAP);
+ conv_value.set_value("four_ary");
  }
  return conv_value;
  }

vpr/src/base/read_route.cpp

@@ -20,7 +20,6 @@
 #include <ctime>
 #include <sstream>
 #include <string>
-#include <unordered_set>
 
 #include "atom_netlist.h"
 #include "atom_netlist_utils.h"
@@ -46,7 +45,6 @@
 #include "route_common.h"
 #include "route_tree.h"
 #include "read_route.h"
-#include "four_ary_heap.h"
 
 #include "old_traceback.h"
 

vpr/src/base/vpr_types.h

@@ -1607,14 +1607,18 @@ constexpr bool is_src_sink(e_rr_type type) { return (type == SOURCE || type == S
  * is being used.
  * @param backward_path_cost Total cost of the path up to and including this
  * node.
- * @param occ The current occupancy of the associated rr node
+ * @param R_upstream Upstream resistance to ground from this node in the current
+ * path search (connection routing), including the resistance
+ * of the node itself (device_ctx.rr_nodes[index].R).
+ * @param occ The current occupancy of the associated rr node.
  */
 struct t_rr_node_route_inf {
  RREdgeId prev_edge;
 
  float acc_cost;
  float path_cost;
  float backward_path_cost;
+ float R_upstream;
 
  public: //Accessors
  short occ() const { return occ_; }