[Interpreter] Add bytecode aging and use it enable CompilationCache for bytecode

src/objects.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_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 #include <memory>
 
@@ skipping 4912 matching lines @@
   int length() { return ByteArray::length() / sizeof(T); }
   DECLARE_CAST(PodArray<T>)
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PodArray<T>);
 };
 
 // BytecodeArray represents a sequence of interpreter bytecodes.
 class BytecodeArray : public FixedArrayBase {
  public:
+#define DECLARE_BYTECODE_AGE_ENUM(X) k##X##BytecodeAge,
+  enum Age {
+    kNoAgeBytecodeAge = 0,
+    CODE_AGE_LIST(DECLARE_BYTECODE_AGE_ENUM) kAfterLastBytecodeAge,
+    kFirstBytecodeAge = kNoAgeBytecodeAge,
+    kLastBytecodeAge = kAfterLastBytecodeAge - 1,
+    kBytecodeAgeCount = kAfterLastBytecodeAge - kFirstBytecodeAge - 1,
+    kIsOldBytecodeAge = kSexagenarianBytecodeAge
+  };
+#undef DECLARE_BYTECODE_AGE_ENUM
+
   static int SizeFor(int length) {
     return OBJECT_POINTER_ALIGN(kHeaderSize + length);
   }
 
   // Setter and getter
   inline byte get(int index);
   inline void set(int index, byte value);
 
   // Returns data start address.
   inline Address GetFirstBytecodeAddress();
@@ skipping 10 matching lines @@
   inline void set_parameter_count(int number_of_parameters);
 
   // Accessors for profiling count.
   inline int interrupt_budget() const;
   inline void set_interrupt_budget(int interrupt_budget);
 
   // Accessors for OSR loop nesting level.
   inline int osr_loop_nesting_level() const;
   inline void set_osr_loop_nesting_level(int depth);
 
+  // Accessors for bytecode's code age.
+  inline Age bytecode_age() const;
+  inline void set_bytecode_age(Age age);
+
   // Accessors for the constant pool.
   DECL_ACCESSORS(constant_pool, FixedArray)
 
   // Accessors for handler table containing offsets of exception handlers.
   DECL_ACCESSORS(handler_table, FixedArray)
 
   // Accessors for source position table containing mappings between byte code
   // offset and source position.
   DECL_ACCESSORS(source_position_table, ByteArray)
 
@@ skipping 11 matching lines @@
   int SourcePosition(int offset);
   int SourceStatementPosition(int offset);
 
   DECLARE_PRINTER(BytecodeArray)
   DECLARE_VERIFIER(BytecodeArray)
 
   void Disassemble(std::ostream& os);
 
   void CopyBytecodesTo(BytecodeArray* to);
 
+  // Bytecode aging
+  bool IsOld() const;
+  void MakeOlder();
+
   // Layout description.
   static const int kConstantPoolOffset = FixedArrayBase::kHeaderSize;
   static const int kHandlerTableOffset = kConstantPoolOffset + kPointerSize;
   static const int kSourcePositionTableOffset =
       kHandlerTableOffset + kPointerSize;
   static const int kFrameSizeOffset = kSourcePositionTableOffset + kPointerSize;
   static const int kParameterSizeOffset = kFrameSizeOffset + kIntSize;
   static const int kInterruptBudgetOffset = kParameterSizeOffset + kIntSize;
   static const int kOSRNestingLevelOffset = kInterruptBudgetOffset + kIntSize;
-  static const int kHeaderSize = kOSRNestingLevelOffset + kCharSize;
+  static const int kBytecodeAgeOffset = kOSRNestingLevelOffset + kCharSize;
+  static const int kHeaderSize = kBytecodeAgeOffset + kCharSize;
 
   // Maximal memory consumption for a single BytecodeArray.
   static const int kMaxSize = 512 * MB;
   // Maximal length of a single BytecodeArray.
   static const int kMaxLength = kMaxSize - kHeaderSize;
 
   static const int kPointerFieldsBeginOffset = kConstantPoolOffset;
   static const int kPointerFieldsEndOffset = kFrameSizeOffset;
 
   typedef FixedBodyDescriptor<kPointerFieldsBeginOffset,
@@ skipping 6888 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_