Revert "Revert "Recognize and optimize a.runtimeType == b.runtimeType pattern.""

runtime/vm/precompiler.h

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_PRECOMPILER_H_
 #define VM_PRECOMPILER_H_
 
 #include "vm/allocation.h"
 #include "vm/hash_map.h"
 #include "vm/hash_table.h"
@@ skipping 338 matching lines @@
 
 typedef DirectChainedHashMap<FieldTypePair> FieldTypeMap;
 
 
 class Precompiler : public ValueObject {
  public:
   static RawError* CompileAll(
       Dart_QualifiedFunctionName embedder_entry_points[],
       bool reset_fields);
 
-  static RawError* CompileFunction(Thread* thread,
+  static RawError* CompileFunction(Precompiler* precompiler,
+                                   Thread* thread,
                                    Zone* zone,
                                    const Function& function,
                                    FieldTypeMap* field_type_map = NULL);
 
   static RawObject* EvaluateStaticInitializer(const Field& field);
   static RawObject* ExecuteOnce(SequenceNode* fragment);
 
   static RawFunction* CompileStaticInitializer(const Field& field,
                                                bool compute_type);
 
+  // Returns true if get:runtimeType is not overloaded by any class.
+  bool get_runtime_type_is_unique() const {
+    return get_runtime_type_is_unique_;
+  }
+
+  FieldTypeMap* field_type_map() {
+    return &field_type_map_;
+  }
+
  private:
   Precompiler(Thread* thread, bool reset_fields);
 
   void DoCompileAll(Dart_QualifiedFunctionName embedder_entry_points[]);
   void ClearAllCode();
   void AddRoots(Dart_QualifiedFunctionName embedder_entry_points[]);
   void AddEntryPoints(Dart_QualifiedFunctionName entry_points[]);
   void Iterate();
 
   void AddType(const AbstractType& type);
@@ skipping 79 matching lines @@
   SymbolSet sent_selectors_;
   FunctionSet enqueued_functions_;
   FieldSet fields_to_retain_;
   FunctionSet functions_to_retain_;
   ClassSet classes_to_retain_;
   TypeArgumentsSet typeargs_to_retain_;
   AbstractTypeSet types_to_retain_;
   InstanceSet consts_to_retain_;
   FieldTypeMap field_type_map_;
   Error& error_;
+
+  bool get_runtime_type_is_unique_;
 };
 
 
 class FunctionsTraits {
  public:
   static const char* Name() { return "FunctionsTraits"; }
   static bool ReportStats() { return false; }
 
   static bool IsMatch(const Object& a, const Object& b) {
     Zone* zone = Thread::Current()->zone();
@@ skipping 16 matching lines @@
     return function.raw();
   }
 };
 
 typedef UnorderedHashSet<FunctionsTraits> UniqueFunctionsSet;
 
 
 }  // namespace dart
 
 #endif  // VM_PRECOMPILER_H_