Vector ICs: ObjectLiteral refactoring for Oracle feedback

src/ast.h

 // Copyright 2012 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_AST_H_
 #define V8_AST_H_
 
 #include "src/assembler.h"
 #include "src/ast-value-factory.h"
 #include "src/bailout-reason.h"
@@ skipping 1381 matching lines @@
   Handle<Map> GetReceiverType() { return receiver_type_; }
 
   bool IsCompileTimeValue();
 
   void set_emit_store(bool emit_store);
   bool emit_store();
 
   bool is_static() const { return is_static_; }
   bool is_computed_name() const { return is_computed_name_; }
 
+  FeedbackVectorICSlot GetSlot(int offset = 0) const {
+    DCHECK(!FLAG_vector_stores || (offset < ic_slot_count_));
+    if (ic_slot_.IsInvalid()) return ic_slot_;
+    return FeedbackVectorICSlot(ic_slot_.ToInt() + offset);
+  }
+
+  int ic_slot_count() const { return ic_slot_count_; }
+
   void set_receiver_type(Handle<Map> map) { receiver_type_ = map; }
+  void set_ic_slot_count(int count) { ic_slot_count_ = count; }
+
+  void set_base_slot(int slot) { ic_slot_ = FeedbackVectorICSlot(slot); }
 
  protected:
   friend class AstNodeFactory;
 
   ObjectLiteralProperty(Expression* key, Expression* value, Kind kind,
                         bool is_static, bool is_computed_name);
   ObjectLiteralProperty(AstValueFactory* ast_value_factory, Expression* key,
                         Expression* value, bool is_static,
                         bool is_computed_name);
 
  private:
   Expression* key_;
   Expression* value_;
   Kind kind_;
+  FeedbackVectorICSlot ic_slot_;
+  int ic_slot_count_;

[Michael Starzinger, 2015/09/07 08:31:13]

As discussed offline, please move these fields either to before the "kind" or
after the boolean flags, so that a compiler can put "kind" and booleans into one
word.

Also as discussed offline, lets make sure the memory overhead of these two new
fields are acceptable by measuring/calculating AST memory footprint on common
workloads.

[mvstanton, 2015/09/07 13:36:09]

Excellent. I've reduced the two new words to one, and am trying to get a picture
of the overall size increase.

   bool emit_store_;
   bool is_static_;
   bool is_computed_name_;
   Handle<Map> receiver_type_;
 };
 
 
 // An object literal has a boilerplate object that is used
 // for minimizing the work when constructing it at runtime.
 class ObjectLiteral final : public MaterializedLiteral {
@@ skipping 43 matching lines @@
     kNoFlags = 0,
     kFastElements = 1,
     kHasFunction = 1 << 1,
     kShallowProperties = 1 << 2,
     kDisableMementos = 1 << 3,
     kIsStrong = 1 << 4
   };
 
   struct Accessors: public ZoneObject {
     Accessors() : getter(NULL), setter(NULL) {}
-    Expression* getter;
-    Expression* setter;
+    // Expression* getter;

[Michael Starzinger, 2015/09/07 08:31:13]

nit: Looks like a left-over.

+    // Expression* setter;
+    ObjectLiteralProperty* getter;
+    ObjectLiteralProperty* setter;
   };
 
   BailoutId CreateLiteralId() const { return BailoutId(local_id(0)); }
 
   // Return an AST id for a property that is used in simulate instructions.
   BailoutId GetIdForProperty(int i) { return BailoutId(local_id(i + 1)); }
 
   // Unlike other AST nodes, this number of bailout IDs allocated for an
   // ObjectLiteral can vary, so num_ids() is not a static method.
   int num_ids() const { return parent_num_ids() + 1 + properties()->length(); }
 
   // Object literals need one feedback slot for each non-trivial value, as well
   // as some slots for home objects.
   FeedbackVectorRequirements ComputeFeedbackRequirements(
       Isolate* isolate, const ICSlotCache* cache) override;
   void SetFirstFeedbackICSlot(FeedbackVectorICSlot slot,
                               ICSlotCache* cache) override {
     slot_ = slot;
   }
   Code::Kind FeedbackICSlotKind(int index) override { return Code::STORE_IC; }
-  FeedbackVectorICSlot GetNthSlot(int n) const {
-    return FeedbackVectorICSlot(slot_.ToInt() + n);
-  }
 
-  // If value needs a home object, returns a valid feedback vector ic slot
-  // given by slot_index, and increments slot_index.
-  FeedbackVectorICSlot SlotForHomeObject(Expression* value,
-                                         int* slot_index) const;
-
-#ifdef DEBUG
-  int slot_count() const { return slot_count_; }
-#endif
+  // After feedback slots were assigned, propagate information to the properties
+  // which need it.
+  void LayoutFeedbackSlots();
 
  protected:
   ObjectLiteral(Zone* zone, ZoneList<Property*>* properties, int literal_index,
                 int boilerplate_properties, bool has_function, bool is_strong,
                 int pos)
       : MaterializedLiteral(zone, literal_index, is_strong, pos),
         properties_(properties),
         boilerplate_properties_(boilerplate_properties),
         fast_elements_(false),
         has_elements_(false),
         may_store_doubles_(false),
         has_function_(has_function),
-#ifdef DEBUG
-        slot_count_(0),
-#endif
         slot_(FeedbackVectorICSlot::Invalid()) {
   }
   static int parent_num_ids() { return MaterializedLiteral::num_ids(); }
 
  private:
   int local_id(int n) const { return base_id() + parent_num_ids() + n; }
   Handle<FixedArray> constant_properties_;
   ZoneList<Property*>* properties_;
   int boilerplate_properties_;
   bool fast_elements_;
   bool has_elements_;
   bool may_store_doubles_;
   bool has_function_;
-#ifdef DEBUG
-  // slot_count_ helps validate that the logic to allocate ic slots and the
-  // logic to use them are in sync.
-  int slot_count_;
-#endif
   FeedbackVectorICSlot slot_;
 };
 
 
 // Node for capturing a regexp literal.
 class RegExpLiteral final : public MaterializedLiteral {
  public:
   DECLARE_NODE_TYPE(RegExpLiteral)
 
   Handle<String> pattern() const { return pattern_->string(); }
@@ skipping 1150 matching lines @@
 
   // Object literals need one feedback slot for each non-trivial value, as well
   // as some slots for home objects.
   FeedbackVectorRequirements ComputeFeedbackRequirements(
       Isolate* isolate, const ICSlotCache* cache) override;
   void SetFirstFeedbackICSlot(FeedbackVectorICSlot slot,
                               ICSlotCache* cache) override {
     slot_ = slot;
   }
   Code::Kind FeedbackICSlotKind(int index) override { return Code::STORE_IC; }
-  FeedbackVectorICSlot GetNthSlot(int n) const {
-    return FeedbackVectorICSlot(slot_.ToInt() + n);
+
+  bool NeedsProxySlot() const {
+    return FLAG_vector_stores && scope() != NULL &&
+           class_variable_proxy()->var()->IsUnallocated();
   }
 
-  // If value needs a home object, returns a valid feedback vector ic slot
-  // given by slot_index, and increments slot_index.
-  FeedbackVectorICSlot SlotForHomeObject(Expression* value,
-                                         int* slot_index) const;
+  FeedbackVectorICSlot ProxySlot() const { return slot_; }
 
-#ifdef DEBUG
-  int slot_count() const { return slot_count_; }
-#endif
+  // After feedback slots were assigned, propagate information to the properties
+  // which need it.
+  void LayoutFeedbackSlots();
 
  protected:
   ClassLiteral(Zone* zone, const AstRawString* name, Scope* scope,
                VariableProxy* class_variable_proxy, Expression* extends,
                FunctionLiteral* constructor, ZoneList<Property*>* properties,
                int start_position, int end_position)
       : Expression(zone, start_position),
         raw_name_(name),
         scope_(scope),
         class_variable_proxy_(class_variable_proxy),
         extends_(extends),
         constructor_(constructor),
         properties_(properties),
         end_position_(end_position),
-#ifdef DEBUG
-        slot_count_(0),
-#endif
         slot_(FeedbackVectorICSlot::Invalid()) {
   }
 
   static int parent_num_ids() { return Expression::num_ids(); }
 
  private:
   int local_id(int n) const { return base_id() + parent_num_ids() + n; }
 
   const AstRawString* raw_name_;
   Scope* scope_;
   VariableProxy* class_variable_proxy_;
   Expression* extends_;
   FunctionLiteral* constructor_;
   ZoneList<Property*>* properties_;
   int end_position_;
-#ifdef DEBUG
-  // slot_count_ helps validate that the logic to allocate ic slots and the
-  // logic to use them are in sync.
-  int slot_count_;
-#endif
   FeedbackVectorICSlot slot_;
 };
 
 
 class NativeFunctionLiteral final : public Expression {
  public:
   DECLARE_NODE_TYPE(NativeFunctionLiteral)
 
   Handle<String> name() const { return name_->string(); }
   v8::Extension* extension() const { return extension_; }
@@ skipping 878 matching lines @@
 
  private:
   Zone* zone_;
   AstValueFactory* ast_value_factory_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_AST_H_