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

src/factory.cc

 // Copyright 2014 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/factory.h"
 
 #include "src/accessors.h"
 #include "src/allocation-site-scopes.h"
 #include "src/ast/ast.h"
 #include "src/base/bits.h"
@@ skipping 1155 matching lines @@
 }
 
 Handle<Cell> Factory::NewCell(Handle<Object> value) {
   AllowDeferredHandleDereference convert_to_cell;
   CALL_HEAP_FUNCTION(
       isolate(),
       isolate()->heap()->AllocateCell(*value),
       Cell);
 }
 
+Handle<Cell> Factory::NewNoClosuresCell(Handle<Object> value) {
+  Handle<Cell> cell = NewCell(value);
+  cell->set_map_no_write_barrier(*no_closures_cell_map());
+  return cell;
+}
+
+Handle<Cell> Factory::NewOneClosureCell(Handle<Object> value) {
+  Handle<Cell> cell = NewCell(value);
+  cell->set_map_no_write_barrier(*one_closure_cell_map());
+  return cell;
+}
+
+Handle<Cell> Factory::NewManyClosuresCell(Handle<Object> value) {
+  Handle<Cell> cell = NewCell(value);
+  cell->set_map_no_write_barrier(*many_closures_cell_map());
+  return cell;
+}
+
 Handle<PropertyCell> Factory::NewPropertyCell() {
   CALL_HEAP_FUNCTION(
       isolate(),
       isolate()->heap()->AllocatePropertyCell(),
       PropertyCell);
 }
 
 
 Handle<WeakCell> Factory::NewWeakCell(Handle<HeapObject> value) {
   // It is safe to dereference the value because we are embedding it
@@ skipping 397 matching lines @@
 }
 
 Handle<JSFunction> Factory::NewFunctionFromSharedFunctionInfo(
     Handle<Map> initial_map, Handle<SharedFunctionInfo> info,
     Handle<Object> context_or_undefined, Handle<Cell> vector,
     PretenureFlag pretenure) {
   DCHECK_EQ(JS_FUNCTION_TYPE, initial_map->instance_type());
   Handle<JSFunction> result =
       NewFunction(initial_map, info, context_or_undefined, pretenure);
 
+  // Bump the closure count that is encoded in the vector cell's map.
+  if (vector->map() == *no_closures_cell_map()) {
+    vector->set_map(*one_closure_cell_map());
+  } else if (vector->map() == *one_closure_cell_map()) {
+    vector->set_map(*many_closures_cell_map());
+  } else {
+    DCHECK_EQ(vector->map(), *many_closures_cell_map());
+  }
+
   result->set_feedback_vector_cell(*vector);
   if (info->ic_age() != isolate()->heap()->global_ic_age()) {
     info->ResetForNewContext(isolate()->heap()->global_ic_age());
   }
 
   if (context_or_undefined->IsContext()) {
     // Give compiler a chance to pre-initialize.
     Compiler::PostInstantiation(result, pretenure);
   }
 
@@ skipping 1245 matching lines @@
     Handle<AccessorInfo> prototype =
         Accessors::FunctionPrototypeInfo(isolate(), rw_attribs);
     Descriptor d = Descriptor::AccessorConstant(
         Handle<Name>(Name::cast(prototype->name())), prototype, rw_attribs);
     map->AppendDescriptor(&d);
   }
 }
 
 }  // namespace internal
 }  // namespace v8