[turbofan] Optimize loads from the global object in JSTypeFeedbackSpecializer.

src/compiler/js-type-feedback.h

 // Copyright 2015 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.
 
 #ifndef V8_COMPILER_JS_TYPE_FEEDBACK_H_
 #define V8_COMPILER_JS_TYPE_FEEDBACK_H_
 
 #include "src/utils.h"
 
 #include "src/compiler/graph-reducer.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/node-aux-data.h"
 #include "src/compiler/simplified-operator.h"
 
 namespace v8 {
 namespace internal {
 
 class TypeFeedbackOracle;
 class SmallMapList;
+class CompilationDependencies;
 
 namespace compiler {
 
 // Stores type feedback information for nodes in the graph in a separate
 // data structure.
 class JSTypeFeedbackTable : public ZoneObject {
  public:
   explicit JSTypeFeedbackTable(Zone* zone);
 
   // TODO(titzer): support recording the feedback vector slot.
@@ skipping 13 matching lines @@
   }
 };
 
 
 // Specializes a graph to the type feedback recorded in the
 // {js_type_feedback} provided to the constructor.
 class JSTypeFeedbackSpecializer : public Reducer {
  public:
   JSTypeFeedbackSpecializer(JSGraph* jsgraph,
                             JSTypeFeedbackTable* js_type_feedback,
-                            TypeFeedbackOracle* oracle)
+                            TypeFeedbackOracle* oracle,
+                            Handle<GlobalObject> global_object,
+                            CompilationDependencies* dependencies)
       : jsgraph_(jsgraph),
         simplified_(jsgraph->graph()->zone()),
         js_type_feedback_(js_type_feedback),
-        oracle_(oracle) {
+        oracle_(oracle),
+        global_object_(global_object),
+        dependencies_(dependencies) {
     CHECK(js_type_feedback);
   }
 
   Reduction Reduce(Node* node) override;
 
   // Visible for unit testing.
   Reduction ReduceJSLoadNamed(Node* node);
+  Reduction ReduceJSLoadNamedForGlobalVariable(Node* node);
   Reduction ReduceJSLoadProperty(Node* node);
   Reduction ReduceJSStoreNamed(Node* node);
   Reduction ReduceJSStoreProperty(Node* node);
 
  private:
   JSGraph* jsgraph_;
   SimplifiedOperatorBuilder simplified_;
   JSTypeFeedbackTable* js_type_feedback_;
   TypeFeedbackOracle* oracle_;
+  Handle<GlobalObject> global_object_;
+  CompilationDependencies* dependencies_;
 
   TypeFeedbackOracle* oracle() { return oracle_; }
   Graph* graph() { return jsgraph_->graph(); }
   JSGraph* jsgraph() { return jsgraph_; }
   CommonOperatorBuilder* common() { return jsgraph_->common(); }
   SimplifiedOperatorBuilder* simplified() { return &simplified_; }
 
   void BuildMapCheck(Node* receiver, Handle<Map> map, bool smi_check,
                      Node* effect, Node* control, Node** success, Node** fail);
 
   void GatherReceiverTypes(Node* receiver, Node* effect, TypeFeedbackId id,
                            Handle<Name> property, SmallMapList* maps);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif