Refactor lithium classes to reduce the number of virtual functions.

src/arm/lithium-arm.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 75 matching lines @@
   V(ConstantI)                                  \
   V(ConstantT)                                  \
   V(Context)                                    \
   V(DeleteProperty)                             \
   V(Deoptimize)                                 \
   V(DivI)                                       \
   V(DoubleToI)                                  \
   V(ExternalArrayLength)                        \
   V(FixedArrayLength)                           \
   V(FunctionLiteral)                            \
-  V(Gap)                                        \
   V(GetCachedArrayIndex)                        \
   V(GlobalObject)                               \
   V(GlobalReceiver)                             \
   V(Goto)                                       \
   V(HasCachedArrayIndex)                        \
   V(HasCachedArrayIndexAndBranch)               \
   V(HasInstanceType)                            \
   V(HasInstanceTypeAndBranch)                   \
   V(InstanceOf)                                 \
   V(InstanceOfAndBranch)                        \
   V(InstanceOfKnownGlobal)                      \
+  V(InstructionGap)                             \
   V(Integer32ToDouble)                          \
   V(InvokeFunction)                             \
   V(IsNull)                                     \
   V(IsNullAndBranch)                            \
   V(IsObject)                                   \
   V(IsObjectAndBranch)                          \
   V(IsSmi)                                      \
   V(IsSmiAndBranch)                             \
   V(JSArrayLength)                              \
   V(Label)                                      \
@@ skipping 46 matching lines @@
   V(Typeof)                                     \
   V(TypeofIs)                                   \
   V(TypeofIsAndBranch)                          \
   V(IsConstructCall)                            \
   V(IsConstructCallAndBranch)                   \
   V(UnaryMathOperation)                         \
   V(UnknownOSRValue)                            \
   V(ValueOf)
 
 
-#define DECLARE_INSTRUCTION(type)                \
-  virtual bool Is##type() const { return true; } \
-  static L##type* cast(LInstruction* instr) {    \
-    ASSERT(instr->Is##type());                   \
-    return reinterpret_cast<L##type*>(instr);    \
+#define DECLARE_CONCRETE_INSTRUCTION(type, mnemonic)              \
+  virtual Opcode opcode() const { return LInstruction::k##type; } \
+  virtual void CompileToNative(LCodeGen* generator);              \
+  virtual const char* Mnemonic() const { return mnemonic; }       \
+  static L##type* cast(LInstruction* instr) {                     \
+    ASSERT(instr->Is##type());                                    \
+    return reinterpret_cast<L##type*>(instr);                     \
   }
 
 
-#define DECLARE_CONCRETE_INSTRUCTION(type, mnemonic)        \
-  virtual void CompileToNative(LCodeGen* generator);        \
-  virtual const char* Mnemonic() const { return mnemonic; } \
-  DECLARE_INSTRUCTION(type)
-
-
 #define DECLARE_HYDROGEN_ACCESSOR(type)     \
   H##type* hydrogen() const {               \
     return H##type::cast(hydrogen_value()); \
   }
 
 
 class LInstruction: public ZoneObject {
  public:
   LInstruction()
       :  environment_(NULL),
          hydrogen_value_(NULL),
          is_call_(false),
          is_save_doubles_(false) { }
   virtual ~LInstruction() { }
 
   virtual void CompileToNative(LCodeGen* generator) = 0;
   virtual const char* Mnemonic() const = 0;
   virtual void PrintTo(StringStream* stream);
   virtual void PrintDataTo(StringStream* stream) = 0;
   virtual void PrintOutputOperandTo(StringStream* stream) = 0;
 
-  // Declare virtual type testers.
-#define DECLARE_DO(type) virtual bool Is##type() const { return false; }
-  LITHIUM_ALL_INSTRUCTION_LIST(DECLARE_DO)
-#undef DECLARE_DO
+  enum Opcode {
+    // Declare a unique enum value for each instruction.
+#define DECLARE_OPCODE(type) k##type,
+    LITHIUM_CONCRETE_INSTRUCTION_LIST(DECLARE_OPCODE)
+    kNumberOfInstructions
+#undef DECLARE_OPCODE
+  };
+
+  virtual Opcode opcode() const = 0;
+
+  // Declare non-virtual type testers for all leaf IR classes.
+#define DECLARE_PREDICATE(type) \
+  bool Is##type() const { return opcode() == k##type; }
+  LITHIUM_CONCRETE_INSTRUCTION_LIST(DECLARE_PREDICATE)
+#undef DECLARE_PREDICATE
+
+  // Declare virtual predicates for instructions that don't have
+  // an opcode.
+  virtual bool IsGap() const { return false; }
 
   virtual bool IsControl() const { return false; }
   virtual void SetBranchTargets(int true_block_id, int false_block_id) { }
 
   void set_environment(LEnvironment* env) { environment_ = env; }
   LEnvironment* environment() const { return environment_; }
   bool HasEnvironment() const { return environment_ != NULL; }
 
   void set_pointer_map(LPointerMap* p) { pointer_map_.set(p); }
   LPointerMap* pointer_map() const { return pointer_map_.get(); }
@@ skipping 106 matching lines @@
 class LGap: public LTemplateInstruction<0, 0, 0> {
  public:
   explicit LGap(HBasicBlock* block)
       : block_(block) {
     parallel_moves_[BEFORE] = NULL;
     parallel_moves_[START] = NULL;
     parallel_moves_[END] = NULL;
     parallel_moves_[AFTER] = NULL;
   }
 
-  DECLARE_CONCRETE_INSTRUCTION(Gap, "gap")
-  virtual void PrintDataTo(StringStream* stream) const;
+  // Can't use the DECLARE-macro here because of sub-classes.
+  virtual bool IsGap() const { return true; }
+  virtual void PrintDataTo(StringStream* stream);
+  static LGap* cast(LInstruction* instr) {
+    ASSERT(instr->IsGap());
+    return reinterpret_cast<LGap*>(instr);
+  }
 
   bool IsRedundant() const;
 
   HBasicBlock* block() const { return block_; }
 
   enum InnerPosition {
     BEFORE,
     START,
     END,
     AFTER,
     FIRST_INNER_POSITION = BEFORE,
     LAST_INNER_POSITION = AFTER
   };
 
   LParallelMove* GetOrCreateParallelMove(InnerPosition pos)  {
     if (parallel_moves_[pos] == NULL) parallel_moves_[pos] = new LParallelMove;
     return parallel_moves_[pos];
   }
 
   LParallelMove* GetParallelMove(InnerPosition pos)  {
     return parallel_moves_[pos];
   }
 
  private:
   LParallelMove* parallel_moves_[LAST_INNER_POSITION + 1];
   HBasicBlock* block_;
 };
 
 
+class LInstructionGap: public LGap {
+ public:
+  explicit LInstructionGap(HBasicBlock* block) : LGap(block) { }
+
+  DECLARE_CONCRETE_INSTRUCTION(InstructionGap, "gap")
+};
+
+
 class LGoto: public LTemplateInstruction<0, 0, 0> {
  public:
   LGoto(int block_id, bool include_stack_check = false)
     : block_id_(block_id), include_stack_check_(include_stack_check) { }
 
   DECLARE_CONCRETE_INSTRUCTION(Goto, "goto")
   virtual void PrintDataTo(StringStream* stream);
   virtual bool IsControl() const { return true; }
 
   int block_id() const { return block_id_; }
@@ skipping 68 matching lines @@
 
 class LUnknownOSRValue: public LTemplateInstruction<1, 0, 0> {
  public:
   DECLARE_CONCRETE_INSTRUCTION(UnknownOSRValue, "unknown-osr-value")
 };
 
 
 template<int I, int T>
 class LControlInstruction: public LTemplateInstruction<0, I, T> {
  public:
-  DECLARE_INSTRUCTION(ControlInstruction)
   virtual bool IsControl() const { return true; }
 
   int true_block_id() const { return true_block_id_; }
   int false_block_id() const { return false_block_id_; }
   void SetBranchTargets(int true_block_id, int false_block_id) {
     true_block_id_ = true_block_id;
     false_block_id_ = false_block_id;
   }
 
  private:
@@ skipping 630 matching lines @@
 class LArithmeticD: public LTemplateInstruction<1, 2, 0> {
  public:
   LArithmeticD(Token::Value op, LOperand* left, LOperand* right)
       : op_(op) {
     inputs_[0] = left;
     inputs_[1] = right;
   }
 
   Token::Value op() const { return op_; }
 
+  virtual Opcode opcode() const { return LInstruction::kArithmeticD; }
   virtual void CompileToNative(LCodeGen* generator);
   virtual const char* Mnemonic() const;
 
  private:
   Token::Value op_;
 };
 
 
 class LArithmeticT: public LTemplateInstruction<1, 2, 0> {
  public:
   LArithmeticT(Token::Value op, LOperand* left, LOperand* right)
       : op_(op) {
     inputs_[0] = left;
     inputs_[1] = right;
   }
 
+  virtual Opcode opcode() const { return LInstruction::kArithmeticT; }
   virtual void CompileToNative(LCodeGen* generator);
   virtual const char* Mnemonic() const;
 
   Token::Value op() const { return op_; }
 
  private:
   Token::Value op_;
 };
 
 
@@ skipping 1067 matching lines @@
   int argument_count_;
   LAllocator* allocator_;
   int position_;
   LInstruction* instruction_pending_deoptimization_environment_;
   int pending_deoptimization_ast_id_;
 
   DISALLOW_COPY_AND_ASSIGN(LChunkBuilder);
 };
 
 #undef DECLARE_HYDROGEN_ACCESSOR
-#undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_LITHIUM_ARM_H_