Count closures using the feedback vector cell map, specialize if count==1.

src/heap/heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/heap/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/ast/context-slot-cache.h"
 #include "src/base/bits.h"
@@ skipping 2315 matching lines @@
     TYPED_ARRAYS(ALLOCATE_FIXED_TYPED_ARRAY_MAP)
 #undef ALLOCATE_FIXED_TYPED_ARRAY_MAP
 
     ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, sloppy_arguments_elements)
 
     ALLOCATE_VARSIZE_MAP(CODE_TYPE, code)
 
     ALLOCATE_MAP(CELL_TYPE, Cell::kSize, cell)
     ALLOCATE_MAP(PROPERTY_CELL_TYPE, PropertyCell::kSize, global_property_cell)
     ALLOCATE_MAP(WEAK_CELL_TYPE, WeakCell::kSize, weak_cell)
+    ALLOCATE_MAP(CELL_TYPE, Cell::kSize, no_closures_cell)
+    ALLOCATE_MAP(CELL_TYPE, Cell::kSize, one_closure_cell)
+    ALLOCATE_MAP(CELL_TYPE, Cell::kSize, many_closures_cell)
     ALLOCATE_MAP(FILLER_TYPE, kPointerSize, one_pointer_filler)
     ALLOCATE_MAP(FILLER_TYPE, 2 * kPointerSize, two_pointer_filler)
 
     ALLOCATE_VARSIZE_MAP(TRANSITION_ARRAY_TYPE, transition_array)
 
     for (unsigned i = 0; i < arraysize(struct_table); i++) {
       const StructTable& entry = struct_table[i];
       Map* map;
       if (!AllocateMap(entry.type, entry.size).To(&map)) return false;
       roots_[entry.index] = map;
@@ skipping 4207 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8