Introduce TypeFeedbackVector, as FixedArray grew constrictive.

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/allocation-site-scopes.h"
 #include "src/base/bits.h"
 #include "src/conversions.h"
 #include "src/isolate-inl.h"
@@ skipping 1868 matching lines @@
 void Factory::BecomeJSObject(Handle<JSProxy> proxy) {
   ReinitializeJSProxy(proxy, JS_OBJECT_TYPE, JSObject::kHeaderSize);
 }
 
 
 void Factory::BecomeJSFunction(Handle<JSProxy> proxy) {
   ReinitializeJSProxy(proxy, JS_FUNCTION_TYPE, JSFunction::kSize);
 }
 
 
-Handle<FixedArray> Factory::NewTypeFeedbackVector(int slot_count) {
+Handle<TypeFeedbackVector> Factory::NewTypeFeedbackVector(int slot_count) {
   // Ensure we can skip the write barrier
   DCHECK_EQ(isolate()->heap()->uninitialized_symbol(),
             *TypeFeedbackInfo::UninitializedSentinel(isolate()));
 
-  CALL_HEAP_FUNCTION(
-      isolate(),
-      isolate()->heap()->AllocateFixedArrayWithFiller(
-          slot_count,
-          TENURED,
-          *TypeFeedbackInfo::UninitializedSentinel(isolate())),
-      FixedArray);
+  if (slot_count == 0) {
+    return Handle<TypeFeedbackVector>::cast(empty_fixed_array());
+  }
+
+  CALL_HEAP_FUNCTION(isolate(),
+                     isolate()->heap()->AllocateFixedArrayWithFiller(
+                         slot_count, TENURED,
+                         *TypeFeedbackInfo::UninitializedSentinel(isolate())),
+                     TypeFeedbackVector);
 }
 
 
 Handle<SharedFunctionInfo> Factory::NewSharedFunctionInfo(
     Handle<String> name, int number_of_literals, FunctionKind kind,
     Handle<Code> code, Handle<ScopeInfo> scope_info,
-    Handle<FixedArray> feedback_vector) {
+    Handle<TypeFeedbackVector> feedback_vector) {
   DCHECK(IsValidFunctionKind(kind));
   Handle<SharedFunctionInfo> shared = NewSharedFunctionInfo(name, code);
   shared->set_scope_info(*scope_info);
   shared->set_feedback_vector(*feedback_vector);
   shared->set_kind(kind);
   int literals_array_size = number_of_literals;
   // If the function contains object, regexp or array literals,
   // allocate extra space for a literals array prefix containing the
   // context.
   if (number_of_literals > 0) {
@@ skipping 47 matching lines @@
   share->set_optimized_code_map(Smi::FromInt(0));
   share->set_scope_info(ScopeInfo::Empty(isolate()));
   Code* construct_stub =
       isolate()->builtins()->builtin(Builtins::kJSConstructStubGeneric);
   share->set_construct_stub(construct_stub);
   share->set_instance_class_name(*Object_string());
   share->set_function_data(*undefined_value(), SKIP_WRITE_BARRIER);
   share->set_script(*undefined_value(), SKIP_WRITE_BARRIER);
   share->set_debug_info(*undefined_value(), SKIP_WRITE_BARRIER);
   share->set_inferred_name(*empty_string(), SKIP_WRITE_BARRIER);
-  share->set_feedback_vector(*empty_fixed_array(), SKIP_WRITE_BARRIER);
+  share->set_feedback_vector(*NewTypeFeedbackVector(0), SKIP_WRITE_BARRIER);
   share->set_profiler_ticks(0);
   share->set_ast_node_count(0);
   share->set_counters(0);
 
   // Set integer fields (smi or int, depending on the architecture).
   share->set_length(0);
   share->set_formal_parameter_count(0);
   share->set_expected_nof_properties(0);
   share->set_num_literals(0);
   share->set_start_position_and_type(0);
@@ skipping 405 matching lines @@
   return Handle<Object>::null();
 }
 
 
 Handle<Object> Factory::ToBoolean(bool value) {
   return value ? true_value() : false_value();
 }
 
 
 } }  // namespace v8::internal