Eliminate some virtual function from AST classes.

src/ast.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 100 matching lines @@
 
 // Typedef only introduced to avoid unreadable code.
 // Please do appreciate the required space in "> >".
 typedef ZoneList<Handle<String> > ZoneStringList;
 typedef ZoneList<Handle<Object> > ZoneObjectList;
 
 
 #define DECLARE_NODE_TYPE(type)                                         \
   virtual void Accept(AstVisitor* v);                                   \
   virtual AstNode::Type node_type() const { return AstNode::k##type; }  \
-  virtual type* As##type() { return this; }
 
 
 class AstNode: public ZoneObject {
  public:
 #define DECLARE_TYPE_ENUM(type) k##type,
   enum Type {
     AST_NODE_LIST(DECLARE_TYPE_ENUM)
     kInvalid = -1
   };
 #undef DECLARE_TYPE_ENUM
@@ skipping 14 matching lines @@
 
   AstNode() {}
 
   virtual ~AstNode() { }
 
   virtual void Accept(AstVisitor* v) = 0;
   virtual Type node_type() const { return kInvalid; }
 
   // Type testing & conversion functions overridden by concrete subclasses.
 #define DECLARE_NODE_FUNCTIONS(type)                  \
-  virtual type* As##type() { return NULL; }
+  bool Is##type() { return node_type() == AstNode::k##type; }          \
+  type* As##type() { return Is##type() ? reinterpret_cast<type*>(this) : NULL; }
   AST_NODE_LIST(DECLARE_NODE_FUNCTIONS)
 #undef DECLARE_NODE_FUNCTIONS
 
   virtual Statement* AsStatement() { return NULL; }
   virtual Expression* AsExpression() { return NULL; }
   virtual TargetCollector* AsTargetCollector() { return NULL; }
   virtual BreakableStatement* AsBreakableStatement() { return NULL; }
   virtual IterationStatement* AsIterationStatement() { return NULL; }
   virtual MaterializedLiteral* AsMaterializedLiteral() { return NULL; }
 
@@ skipping 22 matching lines @@
   friend class CaseClause;  // Generates AST IDs.
 };
 
 
 class Statement: public AstNode {
  public:
   Statement() : statement_pos_(RelocInfo::kNoPosition) {}
 
   virtual Statement* AsStatement()  { return this; }
 
-  virtual Assignment* StatementAsSimpleAssignment() { return NULL; }
-  virtual CountOperation* StatementAsCountOperation() { return NULL; }
-
   bool IsEmpty() { return AsEmptyStatement() != NULL; }
 
   void set_statement_pos(int statement_pos) { statement_pos_ = statement_pos; }
   int statement_pos() const { return statement_pos_; }
 
  private:
   int statement_pos_;
 };
 
 
@@ skipping 45 matching lines @@
       : id_(GetNextId(isolate)),
         test_id_(GetNextId(isolate)) {}
 
   virtual int position() const {
     UNREACHABLE();
     return 0;
   }
 
   virtual Expression* AsExpression()  { return this; }
 
-  virtual bool IsTrivial() { return false; }
   virtual bool IsValidLeftHandSide() { return false; }
 
   // Helpers for ToBoolean conversion.
   virtual bool ToBooleanIsTrue() { return false; }
   virtual bool ToBooleanIsFalse() { return false; }
 
   // Symbols that cannot be parsed as array indices are considered property
   // names.  We do not treat symbols that can be array indexes as property
   // names because [] for string objects is handled only by keyed ICs.
   virtual bool IsPropertyName() { return false; }
 
-  // Mark the expression as being compiled as an expression
-  // statement. This is used to transform postfix increments to
-  // (faster) prefix increments.
-  virtual void MarkAsStatement() { /* do nothing */ }
-
   // True iff the result can be safely overwritten (to avoid allocation).
   // False for operations that can return one of their operands.
   virtual bool ResultOverwriteAllowed() { return false; }
 
   // True iff the expression is a literal represented as a smi.
-  virtual bool IsSmiLiteral() { return false; }
+  bool IsSmiLiteral();
 
   // True iff the expression is a string literal.
-  virtual bool IsStringLiteral() { return false; }
+  bool IsStringLiteral();
 
   // True iff the expression is the null literal.
-  virtual bool IsNullLiteral() { return false; }
+  bool IsNullLiteral();
 
   // Type feedback information for assignments and properties.
   virtual bool IsMonomorphic() {
     UNREACHABLE();
     return false;
   }
-  virtual bool IsArrayLength() {
-    UNREACHABLE();
-    return false;
-  }
   virtual SmallMapList* GetReceiverTypes() {
     UNREACHABLE();
     return NULL;
   }
   Handle<Map> GetMonomorphicReceiverType() {
     ASSERT(IsMonomorphic());
     SmallMapList* types = GetReceiverTypes();
     ASSERT(types != NULL && types->length() == 1);
     return types->at(0);
   }
@@ skipping 45 matching lines @@
 
 class Block: public BreakableStatement {
  public:
   inline Block(Isolate* isolate,
                ZoneStringList* labels,
                int capacity,
                bool is_initializer_block);
 
   DECLARE_NODE_TYPE(Block)
 
-  virtual Assignment* StatementAsSimpleAssignment() {
-    if (statements_.length() != 1) return NULL;
-    return statements_[0]->StatementAsSimpleAssignment();
-  }
-
-  virtual CountOperation* StatementAsCountOperation() {
-    if (statements_.length() != 1) return NULL;
-    return statements_[0]->StatementAsCountOperation();
-  }
-
   virtual bool IsInlineable() const;
 
   void AddStatement(Statement* statement) { statements_.Add(statement); }
 
   ZoneList<Statement*>* statements() { return &statements_; }
   bool is_initializer_block() const { return is_initializer_block_; }
 
   Scope* block_scope() const { return block_scope_; }
   void set_block_scope(Scope* block_scope) { block_scope_ = block_scope; }
 
@@ skipping 214 matching lines @@
 
 class ExpressionStatement: public Statement {
  public:
   explicit ExpressionStatement(Expression* expression)
       : expression_(expression) { }
 
   DECLARE_NODE_TYPE(ExpressionStatement)
 
   virtual bool IsInlineable() const;
 
-  virtual Assignment* StatementAsSimpleAssignment();
-  virtual CountOperation* StatementAsCountOperation();
-
   void set_expression(Expression* e) { expression_ = e; }
   Expression* expression() const { return expression_; }
 
  private:
   Expression* expression_;
 };
 
 
 class ContinueStatement: public Statement {
  public:
@@ skipping 260 matching lines @@
 };
 
 
 class Literal: public Expression {
  public:
   Literal(Isolate* isolate, Handle<Object> handle)
       : Expression(isolate), handle_(handle) { }
 
   DECLARE_NODE_TYPE(Literal)
 
-  virtual bool IsTrivial() { return true; }
-  virtual bool IsSmiLiteral() { return handle_->IsSmi(); }
-  virtual bool IsStringLiteral() { return handle_->IsString(); }
-  virtual bool IsNullLiteral() { return handle_->IsNull(); }
-
   // Check if this literal is identical to the other literal.
   bool IsIdenticalTo(const Literal* other) const {
     return handle_.is_identical_to(other->handle_);
   }
 
   virtual bool IsPropertyName() {
     if (handle_->IsSymbol()) {
       uint32_t ignored;
       return !String::cast(*handle_)->AsArrayIndex(&ignored);
     }
@@ skipping 194 matching lines @@
 class VariableProxy: public Expression {
  public:
   VariableProxy(Isolate* isolate, Variable* var);
 
   DECLARE_NODE_TYPE(VariableProxy)
 
   virtual bool IsValidLeftHandSide() {
     return var_ == NULL ? true : var_->IsValidLeftHandSide();
   }
 
-  virtual bool IsTrivial() {
-    // Reading from a mutable variable is a side effect, but the
-    // variable for 'this' is immutable.
-    return is_this_ || is_trivial_;
-  }
-
   virtual bool IsInlineable() const;
 
   bool IsVariable(Handle<String> n) {
     return !is_this() && name().is_identical_to(n);
   }
 
   bool IsArguments() { return var_ != NULL && var_->is_arguments(); }
 
   Handle<String> name() const { return name_; }
   Variable* var() const { return var_; }
@@ skipping 47 matching lines @@
   virtual int position() const { return pos_; }
 
   bool IsStringLength() const { return is_string_length_; }
   bool IsStringAccess() const { return is_string_access_; }
   bool IsFunctionPrototype() const { return is_function_prototype_; }
 
   // Type feedback information.
   void RecordTypeFeedback(TypeFeedbackOracle* oracle);
   virtual bool IsMonomorphic() { return is_monomorphic_; }
   virtual SmallMapList* GetReceiverTypes() { return &receiver_types_; }
-  virtual bool IsArrayLength() { return is_array_length_; }
+  bool IsArrayLength() { return is_array_length_; }
 
  private:
   Expression* obj_;
   Expression* key_;
   int pos_;
 
   SmallMapList receiver_types_;
   bool is_monomorphic_ : 1;
   bool is_array_length_ : 1;
   bool is_string_length_ : 1;
@@ skipping 923 matching lines @@
 
  private:
   Isolate* isolate_;
   bool stack_overflow_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_AST_H_