Move megamorphic lookup code to stub instead of inlining. Preformance loss < 5%, instruction size r…

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 57 matching lines @@
   V(Subtype2TestCache)                                                         \
   V(Subtype3TestCache)                                                         \
   V(Deoptimize)                                                                \
   V(DeoptimizeLazy)                                                            \
   V(ICCallBreakpoint)                                                          \
   V(ClosureCallBreakpoint)                                                     \
   V(RuntimeCallBreakpoint)                                                     \
   V(UnoptimizedIdenticalWithNumberCheck)                                       \
   V(OptimizedIdenticalWithNumberCheck)                                         \
   V(DebugStepCheck)                                                            \
+  V(MegamorphicLookup)                                                         \
 
 #define STUB_CODE_LIST(V)                                                      \
   BOOTSTRAP_STUB_CODE_LIST(V)                                                  \
   REST_STUB_CODE_LIST(V)
 
 // class StubEntry is used to describe stub methods generated in dart to
 // abstract out common code executed from generated dart code.
 class StubEntry {
  public:
   explicit StubEntry(const Code& code);
@@ skipping 88 matching lines @@
   STUB_CODE_LIST(STUB_CODE_ACCESSOR);
 #undef STUB_CODE_ACCESSOR
 
   static RawCode* GetAllocationStubForClass(const Class& cls);
   RawCode* GetAllocateArrayStub();
 
   uword UnoptimizedStaticCallEntryPoint(intptr_t num_args_tested);
 
   static const intptr_t kNoInstantiator = 0;
 
+  static void EmitMegamorphicLookup(
+      Assembler*, Register recv, Register cache, Register target);
+
  private:
   void GenerateBootstrapStubsFor(Isolate* isolate);
   void GenerateStubsFor(Isolate* isolate);
 
   friend class MegamorphicCacheTable;
 
   static const intptr_t kStubCodeSize = 4 * KB;
 
 #define STUB_CODE_GENERATE(name)                                               \
   static void Generate##name##Stub(Assembler* assembler);
@@ skipping 42 matching lines @@
       Assembler* assembler,
       const Register left,
       const Register right,
       const Register temp1 = kNoRegister,
       const Register temp2 = kNoRegister);
 };
 
 }  // namespace dart
 
 #endif  // VM_STUB_CODE_H_