Allocation folding integrated into the GVN phase.

src/hydrogen-instructions.h

 // Copyright 2012 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 774 matching lines @@
 
   enum Flag {
     kFlexibleRepresentation,
     kCannotBeTagged,
     // Participate in Global Value Numbering, i.e. elimination of
     // unnecessary recomputations. If an instruction sets this flag, it must
     // implement DataEquals(), which will be used to determine if other
     // occurrences of the instruction are indeed the same.
     kUseGVN,
     // Track instructions that are dominating side effects. If an instruction
-    // sets this flag, it must implement SetSideEffectDominator() and should
+    // sets this flag, it must implement HandleSideEffectDominator() and should
     // indicate which side effects to track by setting GVN flags.
     kTrackSideEffectDominators,
     kCanOverflow,
     kBailoutOnMinusZero,
     kCanBeDivByZero,
     kAllowUndefinedAsNaN,
     kIsArguments,
     kTruncatingToInt32,
     kAllUsesTruncatingToInt32,
     // Set after an instruction is killed.
@@ skipping 298 matching lines @@
 
   // Updated the inferred type of this instruction and returns true if
   // it has changed.
   bool UpdateInferredType();
 
   virtual HType CalculateInferredType();
 
   // This function must be overridden for instructions which have the
   // kTrackSideEffectDominators flag set, to track instructions that are
   // dominating side effects.
-  virtual void SetSideEffectDominator(GVNFlag side_effect, HValue* dominator) {
+  virtual void HandleSideEffectDominator(GVNFlag side_effect,
+                                         HValue* dominator) {
     UNREACHABLE();
   }
 
   // Check if this instruction has some reason that prevents elimination.
   bool CannotBeEliminated() const {
     return HasObservableSideEffects() || !IsDeletable();
   }
 
 #ifdef DEBUG
   virtual void Verify() = 0;
@@ skipping 1644 matching lines @@
       }
     };
     check_map->map_set_.Sort();
     return check_map;
   }
 
   virtual bool HasEscapingOperandAt(int index) { return false; }
   virtual Representation RequiredInputRepresentation(int index) {
     return Representation::Tagged();
   }
-  virtual void SetSideEffectDominator(GVNFlag side_effect, HValue* dominator);
+  virtual void HandleSideEffectDominator(GVNFlag side_effect,
+                                         HValue* dominator);
   virtual void PrintDataTo(StringStream* stream);
   virtual HType CalculateInferredType();
 
   HValue* value() { return OperandAt(0); }
   SmallMapList* map_set() { return &map_set_; }
 
   virtual void FinalizeUniqueValueId();
 
   DECLARE_CONCRETE_INSTRUCTION(CheckMaps)
 
@@ skipping 2180 matching lines @@
   // Maximum instance size for which allocations will be inlined.
   static const int kMaxSize = 64 * kPointerSize;
 
   HValue* context() { return OperandAt(0); }
   Handle<JSFunction> constructor() { return constructor_; }
   Handle<Map> constructor_initial_map() { return constructor_initial_map_; }
 
   virtual Representation RequiredInputRepresentation(int index) {
     return Representation::Tagged();
   }
+
   virtual Handle<Map> GetMonomorphicJSObjectMap() {
     ASSERT(!constructor_initial_map_.is_null());
     return constructor_initial_map_;
   }
+
   virtual HType CalculateInferredType();
 
   DECLARE_CONCRETE_INSTRUCTION(AllocateObject)
 
  private:
   // TODO(svenpanne) Might be safe, but leave it out until we know for sure.
   //  virtual bool IsDeletable() const { return true; }
 
   Handle<JSFunction> constructor_;
   Handle<Map> constructor_initial_map_;
 };
 
 
 class HAllocate: public HTemplateInstruction<2> {
  public:
   enum Flags {
     CAN_ALLOCATE_IN_NEW_SPACE = 1 << 0,
     CAN_ALLOCATE_IN_OLD_DATA_SPACE = 1 << 1,
     CAN_ALLOCATE_IN_OLD_POINTER_SPACE = 1 << 2,
     ALLOCATE_DOUBLE_ALIGNED = 1 << 3
   };
 
   HAllocate(HValue* context, HValue* size, HType type, Flags flags)
       : type_(type),
         flags_(flags) {
     SetOperandAt(0, context);
     SetOperandAt(1, size);
     set_representation(Representation::Tagged());
+    SetFlag(kTrackSideEffectDominators);
     SetGVNFlag(kChangesNewSpacePromotion);
+    SetGVNFlag(kDependsOnNewSpacePromotion);
   }
 
   static Flags DefaultFlags() {
     return CAN_ALLOCATE_IN_NEW_SPACE;
   }
 
   static Flags DefaultFlags(ElementsKind kind) {
     Flags flags = CAN_ALLOCATE_IN_NEW_SPACE;
     if (IsFastDoubleElementsKind(kind)) {
       flags = static_cast<HAllocate::Flags>(
           flags | HAllocate::ALLOCATE_DOUBLE_ALIGNED);
     }
     return flags;
   }
 
   HValue* context() { return OperandAt(0); }
   HValue* size() { return OperandAt(1); }
+  HType type() { return type_; }
 
   virtual Representation RequiredInputRepresentation(int index) {
     if (index == 0) {
       return Representation::Tagged();
     } else {
       return Representation::Integer32();
     }
   }
 
   virtual HType CalculateInferredType();
@@ skipping 16 matching lines @@
   }
 
   bool GuaranteedInNewSpace() const {
     return CanAllocateInNewSpace() && !CanAllocateInOldSpace();
   }
 
   bool MustAllocateDoubleAligned() const {
     return (flags_ & ALLOCATE_DOUBLE_ALIGNED) != 0;
   }
 
+  void UpdateSize(HValue* size) {
+    SetOperandAt(1, size);
+  }
+
+  virtual void HandleSideEffectDominator(GVNFlag side_effect,
+                                         HValue* dominator);
+
   virtual void PrintDataTo(StringStream* stream);
 
   DECLARE_CONCRETE_INSTRUCTION(Allocate)
 
  private:
   HType type_;
   Flags flags_;
 };
 
 
 class HInnerAllocatedObject: public HTemplateInstruction<1> {
  public:
-  HInnerAllocatedObject(HValue* value, int offset)
-      : offset_(offset) {
+  HInnerAllocatedObject(HValue* value, int offset, HType type = HType::Tagged())
+      : offset_(offset),
+        type_(type) {
     ASSERT(value->IsAllocate());
     SetOperandAt(0, value);
     set_representation(Representation::Tagged());
   }
 
   HValue* base_object() { return OperandAt(0); }
   int offset() { return offset_; }
 
   virtual Representation RequiredInputRepresentation(int index) {
     return Representation::Tagged();
   }
 
+  virtual HType CalculateInferredType() { return type_; }
+
   virtual void PrintDataTo(StringStream* stream);
 
   DECLARE_CONCRETE_INSTRUCTION(InnerAllocatedObject)
 
  private:
   int offset_;
+  HType type_;
 };
 
 
 inline bool StoringValueNeedsWriteBarrier(HValue* value) {
   return !value->type().IsBoolean()
       && !value->type().IsSmi()
       && !(value->IsConstant() && HConstant::cast(value)->ImmortalImmovable());
 }
 
 
@@ skipping 689 matching lines @@
   virtual Representation RequiredInputRepresentation(int index) {
     if (FLAG_track_double_fields &&
         index == 1 && field_representation_.IsDouble()) {
       return field_representation_;
     } else if (FLAG_track_fields &&
                index == 1 && field_representation_.IsSmi()) {
       return field_representation_;
     }
     return Representation::Tagged();
   }
-  virtual void SetSideEffectDominator(GVNFlag side_effect, HValue* dominator) {
+  virtual void HandleSideEffectDominator(GVNFlag side_effect,
+                                         HValue* dominator) {
     ASSERT(side_effect == kChangesNewSpacePromotion);
     new_space_dominator_ = dominator;
   }
   virtual void PrintDataTo(StringStream* stream);
 
   HValue* object() { return OperandAt(0); }
   HValue* value() { return OperandAt(1); }
 
   HObjectAccess access() const { return access_; }
   Handle<Map> transition() const { return transition_; }
@@ skipping 173 matching lines @@
   void SetDehoisted(bool is_dehoisted) { is_dehoisted_ = is_dehoisted; }
   bool IsUninitialized() { return is_uninitialized_; }
   void SetUninitialized(bool is_uninitialized) {
     is_uninitialized_ = is_uninitialized;
   }
 
   bool IsConstantHoleStore() {
     return value()->IsConstant() && HConstant::cast(value())->IsTheHole();
   }
 
-  virtual void SetSideEffectDominator(GVNFlag side_effect, HValue* dominator) {
+  virtual void HandleSideEffectDominator(GVNFlag side_effect,
+                                         HValue* dominator) {
     ASSERT(side_effect == kChangesNewSpacePromotion);
     new_space_dominator_ = dominator;
   }
 
   HValue* new_space_dominator() const { return new_space_dominator_; }
 
   bool NeedsWriteBarrier() {
     if (value_is_smi()) {
       return false;
     } else {
@@ skipping 670 matching lines @@
   virtual bool IsDeletable() const { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_