Improve memory usage of receiver type feedback.

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 15 matching lines @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef V8_AST_H_
 #define V8_AST_H_
 
 #include "allocation.h"
 #include "execution.h"
 #include "factory.h"
 #include "jsregexp.h"
 #include "runtime.h"
+#include "small-pointer-list.h"
 #include "token.h"
 #include "variables.h"
 
 namespace v8 {
 namespace internal {
 
 // The abstract syntax tree is an intermediate, light-weight
 // representation of the parsed JavaScript code suitable for
 // compilation to native code.
 
@@ skipping 154 matching lines @@
   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_;
 };
 
 
+class SmallMapList {
+ public:
+  SmallMapList() {}
+  explicit SmallMapList(int capacity) : list_(capacity) {}
+
+  void Reserve(int capacty) { list_.Reserve(capacty); }

[fschneider, 2011/08/22 13:38:06]

capacty -> capacity

+  void Clear() { list_.Clear(); }
+
+  bool is_empty() const { return list_.is_empty(); }
+  int length() const { return list_.length(); }
+
+  void Add(Handle<Map> handle) {
+    list_.Add(handle.location());
+  }
+
+  Handle<Map> at(int i) const {
+    return Handle<Map>(list_.at(i));
+  }
+
+  Handle<Map> first() const { return at(0); }
+  Handle<Map> last() const { return at(length() - 1); }
+
+ private:
+  SmallPointerList<Map*> list_;
+
+  DISALLOW_COPY_AND_ASSIGN(SmallMapList);
+};
+
+
 class Expression: public AstNode {
  public:
   enum Context {
     // Not assigned a context yet, or else will not be visited during
     // code generation.
     kUninitialized,
     // Evaluated for its side effects.
     kEffect,
     // Evaluated for its value (and side effects).
     kValue,
@@ skipping 38 matching lines @@
 
   // Type feedback information for assignments and properties.
   virtual bool IsMonomorphic() {
     UNREACHABLE();
     return false;
   }
   virtual bool IsArrayLength() {
     UNREACHABLE();
     return false;
   }
-  virtual ZoneMapList* GetReceiverTypes() {
+  virtual SmallMapList* GetReceiverTypes() {
     UNREACHABLE();
     return NULL;
   }
-  virtual Handle<Map> GetMonomorphicReceiverType() {
-    UNREACHABLE();
-    return Handle<Map>();
+  Handle<Map> GetMonomorphicReceiverType() {
+    ASSERT(IsMonomorphic());
+    SmallMapList* types = GetReceiverTypes();
+    ASSERT(types != NULL && types->length() == 1);
+    return types->at(0);
   }
 
   unsigned id() const { return id_; }
   unsigned test_id() const { return test_id_; }
 
  private:
   unsigned id_;
   unsigned test_id_;
 };
 
@@ skipping 919 matching lines @@
   Property(Isolate* isolate,
            Expression* obj,
            Expression* key,
            int pos,
            Type type = NORMAL)
       : Expression(isolate),
         obj_(obj),
         key_(key),
         pos_(pos),
         type_(type),
-        receiver_types_(NULL),
         is_monomorphic_(false),
         is_array_length_(false),
         is_string_length_(false),
         is_string_access_(false),
         is_function_prototype_(false) { }
 
   DECLARE_NODE_TYPE(Property)
 
   virtual bool IsValidLeftHandSide() { return true; }
   virtual bool IsInlineable() const;
 
   Expression* obj() const { return obj_; }
   Expression* key() const { return key_; }
   virtual int position() const { return pos_; }
   bool is_synthetic() const { return type_ == SYNTHETIC; }
 
   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 ZoneMapList* GetReceiverTypes() { return receiver_types_; }
+  virtual SmallMapList* GetReceiverTypes() { return &receiver_types_; }
   virtual bool IsArrayLength() { return is_array_length_; }
-  virtual Handle<Map> GetMonomorphicReceiverType() {
-    return monomorphic_receiver_type_;
-  }
 
  private:
   Expression* obj_;
   Expression* key_;
   int pos_;
   Type type_;
 
-  ZoneMapList* receiver_types_;
+  SmallMapList receiver_types_;
   bool is_monomorphic_ : 1;
   bool is_array_length_ : 1;
   bool is_string_length_ : 1;
   bool is_string_access_ : 1;
   bool is_function_prototype_ : 1;
-  Handle<Map> monomorphic_receiver_type_;
 };
 
 
 class Call: public Expression {
  public:
   Call(Isolate* isolate,
        Expression* expression,
        ZoneList<Expression*>* arguments,
        int pos)
       : Expression(isolate),
         expression_(expression),
         arguments_(arguments),
         pos_(pos),
         is_monomorphic_(false),
         check_type_(RECEIVER_MAP_CHECK),
-        receiver_types_(NULL),
         return_id_(GetNextId(isolate)) {
   }
 
   DECLARE_NODE_TYPE(Call)
 
   virtual bool IsInlineable() const;
 
   Expression* expression() const { return expression_; }
   ZoneList<Expression*>* arguments() const { return arguments_; }
   virtual int position() const { return pos_; }
 
   void RecordTypeFeedback(TypeFeedbackOracle* oracle,
                           CallKind call_kind);
-  virtual ZoneMapList* GetReceiverTypes() { return receiver_types_; }
+  virtual SmallMapList* GetReceiverTypes() { return &receiver_types_; }
   virtual bool IsMonomorphic() { return is_monomorphic_; }
   CheckType check_type() const { return check_type_; }
   Handle<JSFunction> target() { return target_; }
   Handle<JSObject> holder() { return holder_; }
   Handle<JSGlobalPropertyCell> cell() { return cell_; }
 
   bool ComputeTarget(Handle<Map> type, Handle<String> name);
   bool ComputeGlobalTarget(Handle<GlobalObject> global, LookupResult* lookup);
 
   // Bailout support.
   int ReturnId() const { return return_id_; }
 
 #ifdef DEBUG
   // Used to assert that the FullCodeGenerator records the return site.
   bool return_is_recorded_;
 #endif
 
  private:
   Expression* expression_;
   ZoneList<Expression*>* arguments_;
   int pos_;
 
   bool is_monomorphic_;
   CheckType check_type_;
-  ZoneMapList* receiver_types_;
+  SmallMapList receiver_types_;
   Handle<JSFunction> target_;
   Handle<JSObject> holder_;
   Handle<JSGlobalPropertyCell> cell_;
 
   int return_id_;
 };
 
 
 class AstSentinels {
  public:
@@ skipping 154 matching lines @@
                  Token::Value op,
                  bool is_prefix,
                  Expression* expr,
                  int pos)
       : Expression(isolate),
         op_(op),
         is_prefix_(is_prefix),
         expression_(expr),
         pos_(pos),
         assignment_id_(GetNextId(isolate)),
-        count_id_(GetNextId(isolate)),
-        receiver_types_(NULL) { }
+        count_id_(GetNextId(isolate)) {}
 
   DECLARE_NODE_TYPE(CountOperation)
 
   bool is_prefix() const { return is_prefix_; }
   bool is_postfix() const { return !is_prefix_; }
 
   Token::Value op() const { return op_; }
   Token::Value binary_op() {
     return (op() == Token::INC) ? Token::ADD : Token::SUB;
   }
 
   Expression* expression() const { return expression_; }
   virtual int position() const { return pos_; }
 
   virtual void MarkAsStatement() { is_prefix_ = true; }
 
   virtual bool IsInlineable() const;
 
   void RecordTypeFeedback(TypeFeedbackOracle* oracle);
   virtual bool IsMonomorphic() { return is_monomorphic_; }
-  virtual Handle<Map> GetMonomorphicReceiverType() {
-    return monomorphic_receiver_type_;
-  }
-  virtual ZoneMapList* GetReceiverTypes() { return receiver_types_; }
+  virtual SmallMapList* GetReceiverTypes() { return &receiver_types_; }
 
   // Bailout support.
   int AssignmentId() const { return assignment_id_; }
   int CountId() const { return count_id_; }
 
  private:
   Token::Value op_;
   bool is_prefix_;
   bool is_monomorphic_;
   Expression* expression_;
   int pos_;
   int assignment_id_;
   int count_id_;
-  Handle<Map> monomorphic_receiver_type_;
-  ZoneMapList* receiver_types_;
+  SmallMapList receiver_types_;
 };
 
 
 class CompareOperation: public Expression {
  public:
   CompareOperation(Isolate* isolate,
                    Token::Value op,
                    Expression* left,
                    Expression* right,
                    int pos)
@@ skipping 127 matching lines @@
   // ending of these blocks to allow for optimizations of initialization
   // blocks.
   bool starts_initialization_block() { return block_start_; }
   bool ends_initialization_block() { return block_end_; }
   void mark_block_start() { block_start_ = true; }
   void mark_block_end() { block_end_ = true; }
 
   // Type feedback information.
   void RecordTypeFeedback(TypeFeedbackOracle* oracle);
   virtual bool IsMonomorphic() { return is_monomorphic_; }
-  virtual ZoneMapList* GetReceiverTypes() { return receiver_types_; }
-  virtual Handle<Map> GetMonomorphicReceiverType() {
-    return monomorphic_receiver_type_;
-  }
+  virtual SmallMapList* GetReceiverTypes() { return &receiver_types_; }
 
   // Bailout support.
   int CompoundLoadId() const { return compound_load_id_; }
   int AssignmentId() const { return assignment_id_; }
 
  private:
   Token::Value op_;
   Expression* target_;
   Expression* value_;
   int pos_;
   BinaryOperation* binary_operation_;
   int compound_load_id_;
   int assignment_id_;
 
   bool block_start_;
   bool block_end_;
 
   bool is_monomorphic_;
-  ZoneMapList* receiver_types_;
-  Handle<Map> monomorphic_receiver_type_;
+  SmallMapList receiver_types_;
 };
 
 
 class Throw: public Expression {
  public:
   Throw(Isolate* isolate, Expression* exception, int pos)
       : Expression(isolate), exception_(exception), pos_(pos) {}
 
   DECLARE_NODE_TYPE(Throw)
 
@@ skipping 534 matching lines @@
 
  private:
   Isolate* isolate_;
   bool stack_overflow_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_AST_H_