Cache lookups at megamorphic call sites in optimized code.

runtime/vm/stub_code.h

 // Copyright (c) 2011, 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_STUB_CODE_H_
 #define VM_STUB_CODE_H_
 
 #include "vm/allocation.h"
 #include "vm/assembler.h"
 
@@ skipping 141 matching lines @@
   }
   STUB_CODE_LIST(STUB_CODE_ACCESSOR);
 #undef STUB_CODE_ACCESSOR
 
   static RawCode* GetAllocationStubForClass(const Class& cls);
   static RawCode* GetAllocationStubForClosure(const Function& func);
 
   static const intptr_t kNoInstantiator = 0;
 
  private:
+  friend class MegamorphicCacheTable;
+
   static const intptr_t kStubCodeSize = 4 * KB;
 
 #define STUB_CODE_GENERATE(name)                                               \
   static void Generate##name##Stub(Assembler* assembler);
   VM_STUB_CODE_LIST(STUB_CODE_GENERATE);
   STUB_CODE_LIST(STUB_CODE_GENERATE);
 #undef STUB_CODE_GENERATE
 
 #define STUB_CODE_ENTRY(name)                                                  \
   static StubEntry* name##_entry_;
   VM_STUB_CODE_LIST(STUB_CODE_ENTRY);
 #undef STUB_CODE_ENTRY
 
 #define STUB_CODE_ENTRY(name)                                                  \
   StubEntry* name##_entry_;
   STUB_CODE_LIST(STUB_CODE_ENTRY);
 #undef STUB_CODE_ENTRY
   // This dummy field is needed so that we can intialize the stubs from a macro.
   void* dummy_;
 
   // Generate the stub and finalize the generated code into the stub
   // code executable area.
   static RawCode* Generate(const char* name,
                            void (*GenerateStub)(Assembler* assembler));
 
+  static void GenerateMegamorphicMissStub(Assembler* assembler);
   static void GenerateAllocationStubForClass(Assembler* assembler,
                                              const Class& cls);
   static void GenerateAllocationStubForClosure(Assembler* assembler,
                                                const Function& func);
   static void GenerateNArgsCheckInlineCacheStub(Assembler* assembler,
                                                 intptr_t num_args);
   static void GenerateUsageCounterIncrement(Assembler* assembler,
                                             Register temp_reg);
   static void GenerateOptimizedUsageCounterIncrement(Assembler* assembler);
 };
 
 }  // namespace dart
 
 #endif  // VM_STUB_CODE_H_