Allow merging of monomorphic accesses to tracked fields.

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 6126 matching lines @@
   inline Portion portion() const {
     return PortionField::decode(value_);
   }
 };
 
 
 class HLoadNamedField V8_FINAL : public HTemplateInstruction<2> {
  public:
   DECLARE_INSTRUCTION_FACTORY_P3(HLoadNamedField, HValue*, HValue*,
                                  HObjectAccess);
-  DECLARE_INSTRUCTION_FACTORY_P4(HLoadNamedField, HValue*, HValue*,
-                                 HObjectAccess, Handle<Map>);
+  static HLoadNamedField* New(Zone* zone, HValue* context,
+                              HValue* object, HValue* dependency,
+                              HObjectAccess access, SmallMapList* maps,
+                              CompilationInfo* info) {
+    HLoadNamedField* load_named_field = HLoadNamedField::New(
+        zone, context, object, dependency, access);
+    for (int i = 0; i < maps->length(); ++i) {
+      Handle<Map> map(maps->at(i));
+      load_named_field->map_set_.Add(Unique<Map>(map), zone);
+      if (map->CanTransition()) {
+        Map::AddDependentCompilationInfo(
+            map, DependentCode::kPrototypeCheckGroup, info);
+      }
+    }
+    return load_named_field;
+  }
 
   HValue* object() { return OperandAt(0); }
   HValue* dependency() {
     ASSERT(HasDependency());
     return OperandAt(1);
   }
   bool HasDependency() const { return OperandAt(0) != OperandAt(1); }
   HObjectAccess access() const { return access_; }
   Representation field_representation() const {
       return access_.representation();
   }
 
-  Unique<Map> map() const { return map_; }
+  UniqueSet<Map> map_set() const { return map_set_; }
 
   virtual bool HasEscapingOperandAt(int index) V8_OVERRIDE { return false; }
   virtual bool HasOutOfBoundsAccess(int size) V8_OVERRIDE {
     return !access().IsInobject() || access().offset() >= size;
   }
   virtual Representation RequiredInputRepresentation(int index) V8_OVERRIDE {
     if (index == 0 && access().IsExternalMemory()) {
       // object must be external in case of external memory access
       return Representation::External();
     }
     return Representation::Tagged();
   }
   virtual Range* InferRange(Zone* zone) V8_OVERRIDE;
   virtual void PrintDataTo(StringStream* stream) V8_OVERRIDE;
 
   DECLARE_CONCRETE_INSTRUCTION(LoadNamedField)
 
  protected:
   virtual bool DataEquals(HValue* other) V8_OVERRIDE {
     HLoadNamedField* b = HLoadNamedField::cast(other);
-    return access_.Equals(b->access_) && map_ == b->map_;
+    return access_.Equals(b->access_) && this->map_set_.Equals(&b->map_set_);
   }
 
  private:
   HLoadNamedField(HValue* object,
                   HValue* dependency,
                   HObjectAccess access,
                   Handle<Map> map = Handle<Map>::null())
-      : access_(access), map_(map) {
+      : access_(access) {
     ASSERT(object != NULL);
     SetOperandAt(0, object);
     SetOperandAt(1, dependency != NULL ? dependency : object);
 
     Representation representation = access.representation();
     if (representation.IsInteger8() ||
         representation.IsUInteger8() ||
         representation.IsInteger16() ||
         representation.IsUInteger16()) {
       set_representation(Representation::Integer32());
@@ skipping 13 matching lines @@
       set_representation(Representation::Tagged());
     } else {
       set_representation(Representation::Tagged());
     }
     access.SetGVNFlags(this, LOAD);
   }
 
   virtual bool IsDeletable() const V8_OVERRIDE { return true; }
 
   HObjectAccess access_;
-  Unique<Map> map_;
+  UniqueSet<Map> map_set_;
 };
 
 
 class HLoadNamedGeneric V8_FINAL : public HTemplateInstruction<2> {
  public:
   DECLARE_INSTRUCTION_WITH_CONTEXT_FACTORY_P2(HLoadNamedGeneric, HValue*,
                                               Handle<Object>);
 
   HValue* context() { return OperandAt(0); }
   HValue* object() { return OperandAt(1); }
@@ skipping 1312 matching lines @@
   virtual bool IsDeletable() const V8_OVERRIDE { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_