[Router] Refactored Heap Interface & Removed Deprecated Implementations

- Changed APIs in the `HeapInterface` class.
- Removed the `HeapStorage` class (used for dynamic memory allocations).
- Removed the deprecated bucket heap implementation.
- Replaced the prior k-ary heap implementation with the enhanced d-ary
  heap introduced in commit b11b2e.

Author: ueqri

vpr/src/base/ShowSetup.cpp

@@ -462,9 +462,6 @@ 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

@@ -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"