Remake of the load elimination fix made earlier (r18884).

src/hydrogen.cc

 // Copyright 2013 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 1180 matching lines @@
 }
 
 
 void HGraphBuilder::AddIncrementCounter(StatsCounter* counter) {
   if (FLAG_native_code_counters && counter->Enabled()) {
     HValue* reference = Add<HConstant>(ExternalReference(counter));
     HValue* old_value = Add<HLoadNamedField>(
         reference, static_cast<HValue*>(NULL), HObjectAccess::ForCounter());
     HValue* new_value = AddUncasted<HAdd>(old_value, graph()->GetConstant1());
     new_value->ClearFlag(HValue::kCanOverflow);  // Ignore counter overflow
     Add<HStoreNamedField>(reference, HObjectAccess::ForCounter(),

[Toon Verwaest, 2014/02/03 18:08:28]

join lines

[Igor Sheludko, 2014/02/03 19:17:58]

Done.

-                          new_value, STORE_TO_INITIALIZED_ENTRY);
+                          new_value);
   }
 }
 
 
 void HGraphBuilder::AddSimulate(BailoutId id,
                                 RemovableSimulate removable) {
   ASSERT(current_block() != NULL);
   ASSERT(!graph()->IsInsideNoSideEffectsScope());
   current_block()->AddNewSimulate(id, position_, removable);
 }
@@ skipping 116 matching lines @@
   environment()->Push(new_elements);
   capacity_checker.Else();
 
   environment()->Push(elements);
   capacity_checker.End();
 
   if (is_js_array) {
     HValue* new_length = AddUncasted<HAdd>(key, graph_->GetConstant1());
     new_length->ClearFlag(HValue::kCanOverflow);
 
     Add<HStoreNamedField>(object, HObjectAccess::ForArrayLength(kind),

[Toon Verwaest, 2014/02/03 18:08:28]

join lines

[Igor Sheludko, 2014/02/03 19:17:58]

It will be too long line.

-                          new_length, INITIALIZING_STORE);
+                          new_length);
   }
 
   if (is_store && kind == FAST_SMI_ELEMENTS) {
     HValue* checked_elements = environment()->Top();
 
     // Write zero to ensure that the new element is initialized with some smi.
-    Add<HStoreKeyed>(checked_elements, key, graph()->GetConstant0(), kind,
-                     INITIALIZING_STORE);
+    Add<HStoreKeyed>(checked_elements, key, graph()->GetConstant0(), kind);
   }
 
   length_checker.Else();
   Add<HBoundsCheck>(key, length);
 
   environment()->Push(elements);
   length_checker.End();
 
   return environment()->Pop();
 }
@@ skipping 57 matching lines @@
         ? Add<HLoadNamedField>(object, static_cast<HValue*>(NULL),
                                HObjectAccess::ForArrayLength(from_kind))
         : elements_length;
 
     BuildGrowElementsCapacity(object, elements, from_kind, to_kind,
                               array_length, elements_length);
 
     if_builder.End();
   }
 
-  Add<HStoreNamedField>(object, HObjectAccess::ForMap(), map,
-                        INITIALIZING_STORE);
+  Add<HStoreNamedField>(object, HObjectAccess::ForMap(), map);
 }
 
 
 HValue* HGraphBuilder::BuildUncheckedDictionaryElementLoadHelper(
     HValue* elements,
     HValue* key,
     HValue* hash,
     HValue* mask,
     int current_probe) {
   if (current_probe == kNumberDictionaryProbes) {
@@ skipping 440 matching lines @@
   if_onebyte.Else();
   {
     // We can safely skip the write barrier for storing the map here.
     Handle<Map> map = isolate()->factory()->cons_string_map();
     AddStoreMapConstantNoWriteBarrier(result, map);
   }
   if_onebyte.End();
 
   // Initialize the cons string fields.
   Add<HStoreNamedField>(result, HObjectAccess::ForStringHashField(),
-                        Add<HConstant>(String::kEmptyHashField),
-                        INITIALIZING_STORE);
-  Add<HStoreNamedField>(result, HObjectAccess::ForStringLength(), length,
-                        INITIALIZING_STORE);
-  Add<HStoreNamedField>(result, HObjectAccess::ForConsStringFirst(), left,
-                        INITIALIZING_STORE);
-  Add<HStoreNamedField>(result, HObjectAccess::ForConsStringSecond(), right,
-                        INITIALIZING_STORE);
+                        Add<HConstant>(String::kEmptyHashField));
+  Add<HStoreNamedField>(result, HObjectAccess::ForStringLength(), length);
+  Add<HStoreNamedField>(result, HObjectAccess::ForConsStringFirst(), left);
+  Add<HStoreNamedField>(result, HObjectAccess::ForConsStringSecond(), right);
 
   // Count the native string addition.
   AddIncrementCounter(isolate()->counters()->string_add_native());
 
   return result;
 }
 
 
 void HGraphBuilder::BuildCopySeqStringChars(HValue* src,
                                             HValue* src_offset,
@@ skipping 128 matching lines @@
       // Allocate the string object. HAllocate does not care whether we pass
       // STRING_TYPE or ASCII_STRING_TYPE here, so we just use STRING_TYPE here.
       HAllocate* result = BuildAllocate(
           size, HType::String(), STRING_TYPE, allocation_mode);
 
       // We can safely skip the write barrier for storing map here.
       AddStoreMapNoWriteBarrier(result, map);
 
       // Initialize the string fields.
       Add<HStoreNamedField>(result, HObjectAccess::ForStringHashField(),
-                            Add<HConstant>(String::kEmptyHashField),
-                            INITIALIZING_STORE);
-      Add<HStoreNamedField>(result, HObjectAccess::ForStringLength(), length,
-                            INITIALIZING_STORE);
+                            Add<HConstant>(String::kEmptyHashField));
+      Add<HStoreNamedField>(result, HObjectAccess::ForStringLength(), length);
 
       // Copy characters to the result string.
       IfBuilder if_twobyte(this);
       if_twobyte.If<HCompareObjectEqAndBranch>(map, string_map);
       if_twobyte.Then();
       {
         // Copy characters from the left string.
         BuildCopySeqStringChars(
             left, graph()->GetConstant0(), String::TWO_BYTE_ENCODING,
             result, graph()->GetConstant0(), String::TWO_BYTE_ENCODING,
@@ skipping 280 matching lines @@
 
 void HGraphBuilder::BuildInitializeElementsHeader(HValue* elements,
                                                   ElementsKind kind,
                                                   HValue* capacity) {
   Factory* factory = isolate()->factory();
   Handle<Map> map = IsFastDoubleElementsKind(kind)
       ? factory->fixed_double_array_map()
       : factory->fixed_array_map();
 
   AddStoreMapConstant(elements, map);
   Add<HStoreNamedField>(elements, HObjectAccess::ForFixedArrayLength(),

[Toon Verwaest, 2014/02/03 18:08:28]

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[Igor Sheludko, 2014/02/03 19:17:58]

Too long line.

-                        capacity, INITIALIZING_STORE);
+                        capacity);
 }
 
 
 HValue* HGraphBuilder::BuildAllocateElementsAndInitializeElementsHeader(
     ElementsKind kind,
     HValue* capacity) {
   // The HForceRepresentation is to prevent possible deopt on int-smi
   // conversion after allocation but before the new object fields are set.
   capacity = AddUncasted<HForceRepresentation>(capacity, Representation::Smi());
   HValue* new_elements = BuildAllocateElements(kind, capacity);
   BuildInitializeElementsHeader(new_elements, kind, capacity);
   return new_elements;
 }
 
 
 HInnerAllocatedObject* HGraphBuilder::BuildJSArrayHeader(HValue* array,
     HValue* array_map,
     AllocationSiteMode mode,
     ElementsKind elements_kind,
     HValue* allocation_site_payload,
     HValue* length_field) {
 
-  Add<HStoreNamedField>(array, HObjectAccess::ForMap(), array_map,
-                        INITIALIZING_STORE);
+  Add<HStoreNamedField>(array, HObjectAccess::ForMap(), array_map);
 
   HConstant* empty_fixed_array =
     Add<HConstant>(isolate()->factory()->empty_fixed_array());
 
   HObjectAccess access = HObjectAccess::ForPropertiesPointer();
-  Add<HStoreNamedField>(array, access, empty_fixed_array, INITIALIZING_STORE);
+  Add<HStoreNamedField>(array, access, empty_fixed_array);
   Add<HStoreNamedField>(array, HObjectAccess::ForArrayLength(elements_kind),
-                        length_field, INITIALIZING_STORE);
+                        length_field);
 
   if (mode == TRACK_ALLOCATION_SITE) {
     BuildCreateAllocationMemento(
         array, Add<HConstant>(JSArray::kSize), allocation_site_payload);
   }
 
   int elements_location = JSArray::kSize;
   if (mode == TRACK_ALLOCATION_SITE) {
     elements_location += AllocationMemento::kSize;
   }
 
   HInnerAllocatedObject* elements = Add<HInnerAllocatedObject>(
       array, Add<HConstant>(elements_location));
-  Add<HStoreNamedField>(array, HObjectAccess::ForElementsPointer(), elements,
-                        INITIALIZING_STORE);
+  Add<HStoreNamedField>(array, HObjectAccess::ForElementsPointer(), elements);
   return elements;
 }
 
 
 HInstruction* HGraphBuilder::AddElementAccess(
     HValue* elements,
     HValue* checked_key,
     HValue* val,
     HValue* dependency,
     ElementsKind elements_kind,
@@ skipping 70 matching lines @@
                                                  HValue* new_capacity) {
   BuildNewSpaceArrayCheck(new_capacity, new_kind);
 
   HValue* new_elements = BuildAllocateElementsAndInitializeElementsHeader(
       new_kind, new_capacity);
 
   BuildCopyElements(elements, kind,
                     new_elements, new_kind,
                     length, new_capacity);
 
   Add<HStoreNamedField>(object, HObjectAccess::ForElementsPointer(),

[Toon Verwaest, 2014/02/03 18:08:28]

join lines

[Igor Sheludko, 2014/02/03 19:17:58]

Too long line.

-                        new_elements, INITIALIZING_STORE);
+                        new_elements);
 
   return new_elements;
 }
 
 
 void HGraphBuilder::BuildFillElementsWithHole(HValue* elements,
                                               ElementsKind elements_kind,
                                               HValue* from,
                                               HValue* to) {
   // Fast elements kinds need to be initialized in case statements below cause
@@ skipping 20 matching lines @@
 
   // Since we're about to store a hole value, the store instruction below must
   // assume an elements kind that supports heap object values.
   if (IsFastSmiOrObjectElementsKind(elements_kind)) {
     elements_kind = FAST_HOLEY_ELEMENTS;
   }
 
   if (initial_capacity >= 0) {
     for (int i = 0; i < initial_capacity; i++) {
       HInstruction* key = Add<HConstant>(i);
-      Add<HStoreKeyed>(elements, key, hole, elements_kind,
-                       PREINITIALIZING_STORE);
+      Add<HStoreKeyed>(elements, key, hole, elements_kind);
     }
   } else {
     LoopBuilder builder(this, context(), LoopBuilder::kPostIncrement);
 
     HValue* key = builder.BeginBody(from, to, Token::LT);
 
-    Add<HStoreKeyed>(elements, key, hole, elements_kind, PREINITIALIZING_STORE);
+    Add<HStoreKeyed>(elements, key, hole, elements_kind);
 
     builder.EndBody();
   }
 }
 
 
 void HGraphBuilder::BuildCopyElements(HValue* from_elements,
                                       ElementsKind from_elements_kind,
                                       HValue* to_elements,
                                       ElementsKind to_elements_kind,
@@ skipping 25 matching lines @@
       ? FAST_HOLEY_ELEMENTS : to_elements_kind;
 
   if (IsHoleyElementsKind(from_elements_kind) &&
       from_elements_kind != to_elements_kind) {
     IfBuilder if_hole(this);
     if_hole.If<HCompareHoleAndBranch>(element);
     if_hole.Then();
     HConstant* hole_constant = IsFastDoubleElementsKind(to_elements_kind)
         ? Add<HConstant>(FixedDoubleArray::hole_nan_as_double())
         : graph()->GetConstantHole();
-    Add<HStoreKeyed>(to_elements, key, hole_constant, kind,
-                     PREINITIALIZING_STORE);
+    Add<HStoreKeyed>(to_elements, key, hole_constant, kind);
     if_hole.Else();
-    HStoreKeyed* store = Add<HStoreKeyed>(to_elements, key, element, kind,
-                                          INITIALIZING_STORE);
+    HStoreKeyed* store = Add<HStoreKeyed>(to_elements, key, element, kind);
     store->SetFlag(HValue::kAllowUndefinedAsNaN);
     if_hole.End();
   } else {
-    HStoreKeyed* store = Add<HStoreKeyed>(to_elements, key, element, kind,
-                                          INITIALIZING_STORE);
+    HStoreKeyed* store = Add<HStoreKeyed>(to_elements, key, element, kind);
     store->SetFlag(HValue::kAllowUndefinedAsNaN);
   }
 
   builder.EndBody();
 
   if (!pre_fill_with_holes && length != capacity) {
     // Fill unused capacity with the hole.
     BuildFillElementsWithHole(to_elements, to_elements_kind,
                               key, capacity);
   }
@@ skipping 18 matching lines @@
                                         HType::JSObject(),
                                         NOT_TENURED,
                                         JS_OBJECT_TYPE);
 
   // Copy the JS array part.
   for (int i = 0; i < JSArray::kSize; i += kPointerSize) {
     if ((i != JSArray::kElementsOffset) || (length == 0)) {
       HObjectAccess access = HObjectAccess::ForJSArrayOffset(i);
       Add<HStoreNamedField>(
           object, access, Add<HLoadNamedField>(
-              boilerplate, static_cast<HValue*>(NULL), access),
-          INITIALIZING_STORE);
+              boilerplate, static_cast<HValue*>(NULL), access));
     }
   }
 
   // Create an allocation site info if requested.
   if (mode == TRACK_ALLOCATION_SITE) {
     BuildCreateAllocationMemento(
         object, Add<HConstant>(JSArray::kSize), allocation_site);
   }
 
   if (length > 0) {
     HValue* boilerplate_elements = AddLoadElements(boilerplate);
     HValue* object_elements;
     if (IsFastDoubleElementsKind(kind)) {
       HValue* elems_size = Add<HConstant>(FixedDoubleArray::SizeFor(length));
       object_elements = Add<HAllocate>(elems_size, HType::JSArray(),
           NOT_TENURED, FIXED_DOUBLE_ARRAY_TYPE);
     } else {
       HValue* elems_size = Add<HConstant>(FixedArray::SizeFor(length));
       object_elements = Add<HAllocate>(elems_size, HType::JSArray(),
           NOT_TENURED, FIXED_ARRAY_TYPE);
     }
     Add<HStoreNamedField>(object, HObjectAccess::ForElementsPointer(),
-                          object_elements, INITIALIZING_STORE);
+                          object_elements);
 
     // Copy the elements array header.
     for (int i = 0; i < FixedArrayBase::kHeaderSize; i += kPointerSize) {
       HObjectAccess access = HObjectAccess::ForFixedArrayHeader(i);
       Add<HStoreNamedField>(
           object_elements, access, Add<HLoadNamedField>(
-              boilerplate_elements, static_cast<HValue*>(NULL), access),
-          INITIALIZING_STORE);
+              boilerplate_elements, static_cast<HValue*>(NULL), access));
     }
 
     // Copy the elements array contents.
     // TODO(mstarzinger): Teach HGraphBuilder::BuildCopyElements to unfold
     // copying loops with constant length up to a given boundary and use this
     // helper here instead.
     for (int i = 0; i < length; i++) {
       HValue* key_constant = Add<HConstant>(i);
       HInstruction* value = Add<HLoadKeyed>(boilerplate_elements, key_constant,
                                             static_cast<HValue*>(NULL), kind);
-      Add<HStoreKeyed>(object_elements, key_constant, value, kind,
-                       INITIALIZING_STORE);
+      Add<HStoreKeyed>(object_elements, key_constant, value, kind);
     }
   }
 
   return object;
 }
 
 
 void HGraphBuilder::BuildCompareNil(
     HValue* value,
     Type* type,
@@ skipping 49 matching lines @@
 void HGraphBuilder::BuildCreateAllocationMemento(
     HValue* previous_object,
     HValue* previous_object_size,
     HValue* allocation_site) {
   ASSERT(allocation_site != NULL);
   HInnerAllocatedObject* allocation_memento = Add<HInnerAllocatedObject>(
       previous_object, previous_object_size);
   AddStoreMapConstant(
       allocation_memento, isolate()->factory()->allocation_memento_map());
   Add<HStoreNamedField>(
-      allocation_memento, HObjectAccess::ForAllocationMementoSite(),
-      allocation_site, INITIALIZING_STORE);
+      allocation_memento,
+      HObjectAccess::ForAllocationMementoSite(),
+      allocation_site);
   if (FLAG_allocation_site_pretenuring) {
     HValue* memento_create_count = Add<HLoadNamedField>(
         allocation_site, static_cast<HValue*>(NULL),
         HObjectAccess::ForAllocationSiteOffset(
             AllocationSite::kPretenureCreateCountOffset));
     memento_create_count = AddUncasted<HAdd>(
         memento_create_count, graph()->GetConstant1());
     // This smi value is reset to zero after every gc, overflow isn't a problem
     // since the counter is bounded by the new space size.
     memento_create_count->ClearFlag(HValue::kCanOverflow);
     HStoreNamedField* store = Add<HStoreNamedField>(
         allocation_site, HObjectAccess::ForAllocationSiteOffset(
-            AllocationSite::kPretenureCreateCountOffset), memento_create_count,
-        INITIALIZING_STORE);
+            AllocationSite::kPretenureCreateCountOffset), memento_create_count);
     // No write barrier needed to store a smi.
     store->SkipWriteBarrier();
   }
 }
 
 
 HInstruction* HGraphBuilder::BuildGetNativeContext(HValue* closure) {
   // Get the global context, then the native context
   HInstruction* context =
       Add<HLoadNamedField>(closure, static_cast<HValue*>(NULL),
                            HObjectAccess::ForFunctionContextPointer());
   HInstruction* global_object = Add<HLoadNamedField>(
       context, static_cast<HValue*>(NULL),
       HObjectAccess::ForContextSlot(Context::GLOBAL_OBJECT_INDEX));
-  HObjectAccess access = HObjectAccess::ForJSObjectOffset(
+  HObjectAccess access = HObjectAccess::ForObservableJSObjectPropertyAt(
       GlobalObject::kNativeContextOffset);
   return Add<HLoadNamedField>(
       global_object, static_cast<HValue*>(NULL), access);
 }
 
 
 HInstruction* HGraphBuilder::BuildGetNativeContext() {
   // Get the global context, then the native context
   HValue* global_object = Add<HLoadNamedField>(
       context(), static_cast<HValue*>(NULL),
       HObjectAccess::ForContextSlot(Context::GLOBAL_OBJECT_INDEX));
   return Add<HLoadNamedField>(
       global_object, static_cast<HValue*>(NULL),
-      HObjectAccess::ForJSObjectOffset(GlobalObject::kNativeContextOffset));
+      HObjectAccess::ForObservableJSObjectPropertyAt(
+          GlobalObject::kNativeContextOffset));
 }
 
 
 HInstruction* HGraphBuilder::BuildGetArrayFunction() {
   HInstruction* native_context = BuildGetNativeContext();
   HInstruction* index =
       Add<HConstant>(static_cast<int32_t>(Context::ARRAY_FUNCTION_INDEX));
   return Add<HLoadKeyed>(
       native_context, index, static_cast<HValue*>(NULL), FAST_ELEMENTS);
 }
@@ skipping 170 matching lines @@
                                          graph()->GetConstant0(), capacity);
   }
 
   return new_object;
 }
 
 
 HStoreNamedField* HGraphBuilder::AddStoreMapConstant(HValue *object,
                                                      Handle<Map> map) {
   return Add<HStoreNamedField>(object, HObjectAccess::ForMap(),
-                               Add<HConstant>(map), INITIALIZING_STORE);
+                               Add<HConstant>(map));
 }
 
 
 HValue* HGraphBuilder::AddLoadJSBuiltin(Builtins::JavaScript builtin) {
   HValue* global_object = Add<HLoadNamedField>(
       context(), static_cast<HValue*>(NULL),
       HObjectAccess::ForContextSlot(Context::GLOBAL_OBJECT_INDEX));
-  HObjectAccess access = HObjectAccess::ForJSObjectOffset(
+  HObjectAccess access = HObjectAccess::ForObservableJSObjectPropertyAt(
       GlobalObject::kBuiltinsOffset);
   HValue* builtins = Add<HLoadNamedField>(
       global_object, static_cast<HValue*>(NULL), access);
-  HObjectAccess function_access = HObjectAccess::ForJSObjectOffset(
-      JSBuiltinsObject::OffsetOfFunctionWithId(builtin));
+  HObjectAccess function_access =
+      HObjectAccess::ForObservableJSObjectPropertyAt(
+          JSBuiltinsObject::OffsetOfFunctionWithId(builtin));
   return Add<HLoadNamedField>(
       builtins, static_cast<HValue*>(NULL), function_access);
 }
 
 
 HOptimizedGraphBuilder::HOptimizedGraphBuilder(CompilationInfo* info)
     : HGraphBuilder(info),
       function_state_(NULL),
       initial_function_state_(this, info, NORMAL_RETURN),
       ast_context_(NULL),
@@ skipping 2298 matching lines @@
     HValue* key = Add<HConstant>(i);
 
     switch (boilerplate_elements_kind) {
       case FAST_SMI_ELEMENTS:
       case FAST_HOLEY_SMI_ELEMENTS:
       case FAST_ELEMENTS:
       case FAST_HOLEY_ELEMENTS:
       case FAST_DOUBLE_ELEMENTS:
       case FAST_HOLEY_DOUBLE_ELEMENTS: {
         HStoreKeyed* instr = Add<HStoreKeyed>(elements, key, value,
-                                              boilerplate_elements_kind,
-                                              INITIALIZING_STORE);
+                                              boilerplate_elements_kind);
         instr->SetUninitialized(uninitialized);
         break;
       }
       default:
         UNREACHABLE();
         break;
     }
 
     Add<HSimulate>(expr->GetIdForElement(i));
   }
@@ skipping 60 matching lines @@
 
       PretenureFlag pretenure_flag = !FLAG_allocation_site_pretenuring ?
           isolate()->heap()->GetPretenureMode() : NOT_TENURED;
 
       HInstruction* heap_number = Add<HAllocate>(heap_number_size,
           HType::HeapNumber(),
           pretenure_flag,
           HEAP_NUMBER_TYPE);
       AddStoreMapConstant(heap_number, isolate()->factory()->heap_number_map());
       Add<HStoreNamedField>(heap_number, HObjectAccess::ForHeapNumberValue(),
-                            value, INITIALIZING_STORE);
+                            value);
       instr = New<HStoreNamedField>(checked_object->ActualValue(),
                                     heap_number_access,
-                                    heap_number, INITIALIZING_STORE);
+                                    heap_number);
     } else {
       // Already holds a HeapNumber; load the box and write its value field.
       HInstruction* heap_number = Add<HLoadNamedField>(
           checked_object, static_cast<HValue*>(NULL), heap_number_access);
       heap_number->set_type(HType::HeapNumber());
       instr = New<HStoreNamedField>(heap_number,
                                     HObjectAccess::ForHeapNumberValue(),
-                                    value, STORE_TO_INITIALIZED_ENTRY);
+                                    value);
     }
   } else {
     // This is a normal store.
     instr = New<HStoreNamedField>(
         checked_object->ActualValue(), field_access, value,
         transition_to_field ? INITIALIZING_STORE : STORE_TO_INITIALIZED_ENTRY);
   }
 
   if (transition_to_field) {
     Handle<Map> transition(lookup->GetTransitionMapFromMap(*map));
@@ skipping 2612 matching lines @@
   }
 }
 
 
 HValue* HOptimizedGraphBuilder::ImplicitReceiverFor(HValue* function,
                                                     Handle<JSFunction> target) {
   SharedFunctionInfo* shared = target->shared();
   if (shared->is_classic_mode() && !shared->native()) {
     HValue* context = Add<HLoadNamedField>(
         function, static_cast<HValue*>(NULL),
-        HObjectAccess::ForJSObjectOffset(JSFunction::kContextOffset));
+        HObjectAccess::ForMapAndOffset(handle(target->map()),
+                                       JSFunction::kContextOffset));
     HValue* global_object = Add<HLoadNamedField>(
         context, static_cast<HValue*>(NULL),
         HObjectAccess::ForContextSlot(Context::GLOBAL_OBJECT_INDEX));
     return Add<HLoadNamedField>(
         global_object, static_cast<HValue*>(NULL),
-        HObjectAccess::ForJSObjectOffset(
+        HObjectAccess::ForMapAndOffset(
+            handle(target->context()->global_object()->map()),
             GlobalObject::kGlobalReceiverOffset));
   }
   return graph()->GetConstantUndefined();
 }
 
 
 void HOptimizedGraphBuilder::VisitCall(Call* expr) {
   ASSERT(!HasStackOverflow());
   ASSERT(current_block() != NULL);
   ASSERT(current_block()->HasPredecessor());
@@ skipping 260 matching lines @@
     // TODO(mvstanton): If all the arguments are constants in smi range, then
     // we could set fill_with_hole to false and save a few instructions.
     JSArrayBuilder::FillMode fill_mode = IsFastSmiElementsKind(kind)
         ? JSArrayBuilder::FILL_WITH_HOLE
         : JSArrayBuilder::DONT_FILL_WITH_HOLE;
     new_object = array_builder.AllocateArray(length, length, fill_mode);
     HValue* elements = array_builder.GetElementsLocation();
     for (int i = 0; i < argument_count; i++) {
       HValue* value = environment()->ExpressionStackAt(argument_count - i - 1);
       HValue* constant_i = Add<HConstant>(i);
-      Add<HStoreKeyed>(elements, constant_i, value, kind, INITIALIZING_STORE);
+      Add<HStoreKeyed>(elements, constant_i, value, kind);
     }
   }
 
   Drop(argument_count + 1);  // drop constructor and args.
   ast_context()->ReturnValue(new_object);
 }
 
 
 // Checks whether allocation using the given constructor can be inlined.
 static bool IsAllocationInlineable(Handle<JSFunction> constructor) {
@@ skipping 88 matching lines @@
             isolate()->heap()->GetPretenureMode() : NOT_TENURED;
     HAllocate* receiver =
         Add<HAllocate>(size_in_bytes, HType::JSObject(), pretenure_flag,
         JS_OBJECT_TYPE);
     receiver->set_known_initial_map(initial_map);
 
     // Load the initial map from the constructor.
     HValue* constructor_value = Add<HConstant>(constructor);
     HValue* initial_map_value =
       Add<HLoadNamedField>(constructor_value, static_cast<HValue*>(NULL),
-                           HObjectAccess::ForJSObjectOffset(
+                           HObjectAccess::ForMapAndOffset(
+                               handle(constructor->map()),
                                JSFunction::kPrototypeOrInitialMapOffset));
 
     // Initialize map and fields of the newly allocated object.
     { NoObservableSideEffectsScope no_effects(this);
       ASSERT(initial_map->instance_type() == JS_OBJECT_TYPE);
       Add<HStoreNamedField>(receiver,
-          HObjectAccess::ForJSObjectOffset(JSObject::kMapOffset),
-          initial_map_value, INITIALIZING_STORE);
+          HObjectAccess::ForMapAndOffset(initial_map, JSObject::kMapOffset),
+          initial_map_value);
       HValue* empty_fixed_array = Add<HConstant>(factory->empty_fixed_array());
       Add<HStoreNamedField>(receiver,
-          HObjectAccess::ForJSObjectOffset(JSObject::kPropertiesOffset),
-          empty_fixed_array, INITIALIZING_STORE);
+          HObjectAccess::ForMapAndOffset(initial_map,
+                                           JSObject::kPropertiesOffset),
+          empty_fixed_array);
       Add<HStoreNamedField>(receiver,
-          HObjectAccess::ForJSObjectOffset(JSObject::kElementsOffset),
-          empty_fixed_array, INITIALIZING_STORE);
+          HObjectAccess::ForMapAndOffset(initial_map,
+                                           JSObject::kElementsOffset),
+          empty_fixed_array);
       if (initial_map->inobject_properties() != 0) {
         HConstant* undefined = graph()->GetConstantUndefined();
         for (int i = 0; i < initial_map->inobject_properties(); i++) {
-          int property_offset = JSObject::kHeaderSize + i * kPointerSize;
+          int property_offset = initial_map->GetInObjectPropertyOffset(i);
           Add<HStoreNamedField>(receiver,
-              HObjectAccess::ForJSObjectOffset(property_offset),
-              undefined, PREINITIALIZING_STORE);
+              HObjectAccess::ForMapAndOffset(initial_map, property_offset),
+              undefined);
         }
       }
     }
 
     // Replace the constructor function with a newly allocated receiver using
     // the index of the receiver from the top of the expression stack.
     const int receiver_index = argument_count - 1;
     ASSERT(environment()->ExpressionStackAt(receiver_index) == function);
     environment()->SetExpressionStackAt(receiver_index, receiver);
 
@@ skipping 63 matching lines @@
 void HGraphBuilder::BuildArrayBufferViewInitialization(
     HValue* obj,
     HValue* buffer,
     HValue* byte_offset,
     HValue* byte_length) {
 
   for (int offset = ViewClass::kSize;
        offset < ViewClass::kSizeWithInternalFields;
        offset += kPointerSize) {
     Add<HStoreNamedField>(obj,
-        HObjectAccess::ForJSObjectOffset(offset),
-        graph()->GetConstant0(), INITIALIZING_STORE);
+        HObjectAccess::ForObservableJSObjectPropertyAt(offset),
+        graph()->GetConstant0());
   }
 
   Add<HStoreNamedField>(
       obj,
-      HObjectAccess::ForJSArrayBufferViewBuffer(), buffer, INITIALIZING_STORE);
+      HObjectAccess::ForJSArrayBufferViewBuffer(), buffer);
   Add<HStoreNamedField>(
       obj,
       HObjectAccess::ForJSArrayBufferViewByteOffset(),
-      byte_offset, INITIALIZING_STORE);
+      byte_offset);
   Add<HStoreNamedField>(
       obj,
       HObjectAccess::ForJSArrayBufferViewByteLength(),
-      byte_length, INITIALIZING_STORE);
+      byte_length);
 
   HObjectAccess weak_first_view_access =
       HObjectAccess::ForJSArrayBufferWeakFirstView();
   Add<HStoreNamedField>(obj,
       HObjectAccess::ForJSArrayBufferViewWeakNext(),
       Add<HLoadNamedField>(buffer, static_cast<HValue*>(NULL),
-                           weak_first_view_access),
-      INITIALIZING_STORE);
+                           weak_first_view_access));
   Add<HStoreNamedField>(
-      buffer, weak_first_view_access, obj, INITIALIZING_STORE);
+      buffer, weak_first_view_access, obj);
 }
 
 
 void HOptimizedGraphBuilder::VisitDataViewInitialize(
     CallRuntime* expr) {
   ZoneList<Expression*>* arguments = expr->arguments();
 
   NoObservableSideEffectsScope scope(this);
   ASSERT(arguments->length()== 4);
   CHECK_ALIVE(VisitForValue(arguments->at(0)));
@@ skipping 69 matching lines @@
 
     ExternalArrayType array_type = kExternalInt8Array;  // Bogus initialization.
     size_t element_size = 1;  // Bogus initialization.
     Runtime::ArrayIdToTypeAndSize(array_id, &array_type, &element_size);
 
     HInstruction* length = AddUncasted<HDiv>(byte_length,
         Add<HConstant>(static_cast<int32_t>(element_size)));
 
     Add<HStoreNamedField>(obj,
         HObjectAccess::ForJSTypedArrayLength(),
-        length, INITIALIZING_STORE);
+        length);
 
     HValue* elements =
         Add<HAllocate>(
             Add<HConstant>(ExternalArray::kAlignedSize),
             HType::JSArray(),
             NOT_TENURED,
             static_cast<InstanceType>(FIRST_EXTERNAL_ARRAY_TYPE + array_type));
 
     Handle<Map> external_array_map(
         isolate()->heap()->MapForExternalArrayType(array_type));
-    AddStoreMapConstant(elements, external_array_map);
+    Add<HStoreNamedField>(elements,
+        HObjectAccess::ForMap(),
+        Add<HConstant>(external_array_map));
 
     HValue* backing_store = Add<HLoadNamedField>(
         buffer, static_cast<HValue*>(NULL),
         HObjectAccess::ForJSArrayBufferBackingStore());
 
     HValue* typed_array_start;
     if (is_zero_byte_offset) {
       typed_array_start = backing_store;
     } else {
       HInstruction* external_pointer =
           AddUncasted<HAdd>(backing_store, byte_offset);
       // Arguments are checked prior to call to TypedArrayInitialize,
       // including byte_offset.
       external_pointer->ClearFlag(HValue::kCanOverflow);
       typed_array_start = external_pointer;
     }
 
+    Add<HStoreNamedField>(elements,
+        HObjectAccess::ForExternalArrayExternalPointer(),
+        typed_array_start);
+    Add<HStoreNamedField>(elements,
+        HObjectAccess::ForFixedArrayLength(),
+        length);
     Add<HStoreNamedField>(
-        elements, HObjectAccess::ForExternalArrayExternalPointer(),
-        typed_array_start, INITIALIZING_STORE);
-    Add<HStoreNamedField>(
-        elements, HObjectAccess::ForFixedArrayLength(), length,
-        INITIALIZING_STORE);
-    Add<HStoreNamedField>(
-        obj, HObjectAccess::ForElementsPointer(), elements, INITIALIZING_STORE);
+        obj, HObjectAccess::ForElementsPointer(), elements);
   }
 
   if (!is_zero_byte_offset) {
     byte_offset_smi.Else();
     { //  byte_offset is not Smi.
       Push(Add<HPushArgument>(obj));
       VisitArgument(arguments->at(kArrayIdArg));
       Push(Add<HPushArgument>(buffer));
       Push(Add<HPushArgument>(byte_offset));
       Push(Add<HPushArgument>(byte_length));
@@ skipping 1219 matching lines @@
   ASSERT(boilerplate_object->properties()->length() == 0);
 
   Handle<Map> boilerplate_object_map(boilerplate_object->map());
   AddStoreMapConstant(object, boilerplate_object_map);
 
   Handle<Object> properties_field =
       Handle<Object>(boilerplate_object->properties(), isolate());
   ASSERT(*properties_field == isolate()->heap()->empty_fixed_array());
   HInstruction* properties = Add<HConstant>(properties_field);
   HObjectAccess access = HObjectAccess::ForPropertiesPointer();
-  Add<HStoreNamedField>(object, access, properties, INITIALIZING_STORE);
+  Add<HStoreNamedField>(object, access, properties);
 
   if (boilerplate_object->IsJSArray()) {
     Handle<JSArray> boilerplate_array =
         Handle<JSArray>::cast(boilerplate_object);
     Handle<Object> length_field =
         Handle<Object>(boilerplate_array->length(), isolate());
     HInstruction* length = Add<HConstant>(length_field);
 
     ASSERT(boilerplate_array->length()->IsSmi());
     Add<HStoreNamedField>(object, HObjectAccess::ForArrayLength(
-        boilerplate_array->GetElementsKind()), length, INITIALIZING_STORE);
+        boilerplate_array->GetElementsKind()), length);
   }
 }
 
 
 void HOptimizedGraphBuilder::BuildInitElementsInObjectHeader(
     Handle<JSObject> boilerplate_object,
     HInstruction* object,
     HInstruction* object_elements) {
   ASSERT(boilerplate_object->properties()->length() == 0);
   if (object_elements == NULL) {
     Handle<Object> elements_field =
         Handle<Object>(boilerplate_object->elements(), isolate());
     object_elements = Add<HConstant>(elements_field);
   }
   Add<HStoreNamedField>(object, HObjectAccess::ForElementsPointer(),
-      object_elements, INITIALIZING_STORE);
+      object_elements);
 }
 
 
 void HOptimizedGraphBuilder::BuildEmitInObjectProperties(
     Handle<JSObject> boilerplate_object,
     HInstruction* object,
     AllocationSiteUsageContext* site_context,
     PretenureFlag pretenure_flag) {
-  Handle<DescriptorArray> descriptors(
-      boilerplate_object->map()->instance_descriptors());
-  int limit = boilerplate_object->map()->NumberOfOwnDescriptors();
+  Handle<Map> boilerplate_map(boilerplate_object->map());
+  Handle<DescriptorArray> descriptors(boilerplate_map->instance_descriptors());
+  int limit = boilerplate_map->NumberOfOwnDescriptors();
 
   int copied_fields = 0;
   for (int i = 0; i < limit; i++) {
     PropertyDetails details = descriptors->GetDetails(i);
     if (details.type() != FIELD) continue;
     copied_fields++;
     int index = descriptors->GetFieldIndex(i);
     int property_offset = boilerplate_object->GetInObjectPropertyOffset(index);
     Handle<Name> name(descriptors->GetKey(i));
     Handle<Object> value =
         Handle<Object>(boilerplate_object->InObjectPropertyAt(index),
         isolate());
 
     // The access for the store depends on the type of the boilerplate.
     HObjectAccess access = boilerplate_object->IsJSArray() ?
         HObjectAccess::ForJSArrayOffset(property_offset) :
-        HObjectAccess::ForJSObjectOffset(property_offset);
+        HObjectAccess::ForMapAndOffset(boilerplate_map, property_offset);
 
     if (value->IsJSObject()) {
       Handle<JSObject> value_object = Handle<JSObject>::cast(value);
       Handle<AllocationSite> current_site = site_context->EnterNewScope();
       HInstruction* result =
           BuildFastLiteral(value_object, site_context);
       site_context->ExitScope(current_site, value_object);
-      Add<HStoreNamedField>(object, access, result, INITIALIZING_STORE);
+      Add<HStoreNamedField>(object, access, result);
     } else {
       Representation representation = details.representation();
       HInstruction* value_instruction;
 
       if (representation.IsDouble()) {
         // Allocate a HeapNumber box and store the value into it.
         HValue* heap_number_constant = Add<HConstant>(HeapNumber::kSize);
         // This heap number alloc does not have a corresponding
         // AllocationSite. That is okay because
         // 1) it's a child object of another object with a valid allocation site
         // 2) we can just use the mode of the parent object for pretenuring
         HInstruction* double_box =
             Add<HAllocate>(heap_number_constant, HType::HeapNumber(),
                 pretenure_flag, HEAP_NUMBER_TYPE);
         AddStoreMapConstant(double_box,
             isolate()->factory()->heap_number_map());
         Add<HStoreNamedField>(double_box, HObjectAccess::ForHeapNumberValue(),
-                              Add<HConstant>(value), INITIALIZING_STORE);
+                              Add<HConstant>(value));
         value_instruction = double_box;
       } else if (representation.IsSmi() && value->IsUninitialized()) {
         value_instruction = graph()->GetConstant0();
       } else {
         value_instruction = Add<HConstant>(value);
       }
 
-      Add<HStoreNamedField>(object, access, value_instruction,
-                            INITIALIZING_STORE);
+      Add<HStoreNamedField>(object, access, value_instruction);
     }
   }
 
   int inobject_properties = boilerplate_object->map()->inobject_properties();
   HInstruction* value_instruction =
       Add<HConstant>(isolate()->factory()->one_pointer_filler_map());
   for (int i = copied_fields; i < inobject_properties; i++) {
     ASSERT(boilerplate_object->IsJSObject());
     int property_offset = boilerplate_object->GetInObjectPropertyOffset(i);
-    HObjectAccess access = HObjectAccess::ForJSObjectOffset(property_offset);
-    Add<HStoreNamedField>(object, access, value_instruction,
-                          PREINITIALIZING_STORE);
+    HObjectAccess access =
+        HObjectAccess::ForMapAndOffset(boilerplate_map, property_offset);
+    Add<HStoreNamedField>(object, access, value_instruction);
   }
 }
 
 
 void HOptimizedGraphBuilder::BuildEmitElements(
     Handle<JSObject> boilerplate_object,
     Handle<FixedArrayBase> elements,
     HValue* object_elements,
     AllocationSiteUsageContext* site_context) {
   ElementsKind kind = boilerplate_object->map()->elements_kind();
@@ skipping 19 matching lines @@
     HValue* object_elements) {
   HInstruction* boilerplate_elements = Add<HConstant>(elements);
   int elements_length = elements->length();
   for (int i = 0; i < elements_length; i++) {
     HValue* key_constant = Add<HConstant>(i);
     HInstruction* value_instruction =
         Add<HLoadKeyed>(boilerplate_elements, key_constant,
                         static_cast<HValue*>(NULL), kind,
                         ALLOW_RETURN_HOLE);
     HInstruction* store = Add<HStoreKeyed>(object_elements, key_constant,
-                                           value_instruction, kind,
-                                           INITIALIZING_STORE);
+                                           value_instruction, kind);
     store->SetFlag(HValue::kAllowUndefinedAsNaN);
   }
 }
 
 
 void HOptimizedGraphBuilder::BuildEmitFixedArray(
     Handle<FixedArrayBase> elements,
     ElementsKind kind,
     HValue* object_elements,
     AllocationSiteUsageContext* site_context) {
   HInstruction* boilerplate_elements = Add<HConstant>(elements);
   int elements_length = elements->length();
   Handle<FixedArray> fast_elements = Handle<FixedArray>::cast(elements);
   for (int i = 0; i < elements_length; i++) {
     Handle<Object> value(fast_elements->get(i), isolate());
     HValue* key_constant = Add<HConstant>(i);
     if (value->IsJSObject()) {
       Handle<JSObject> value_object = Handle<JSObject>::cast(value);
       Handle<AllocationSite> current_site = site_context->EnterNewScope();
       HInstruction* result =
           BuildFastLiteral(value_object, site_context);
       site_context->ExitScope(current_site, value_object);
-      Add<HStoreKeyed>(object_elements, key_constant, result, kind,
-                       INITIALIZING_STORE);
+      Add<HStoreKeyed>(object_elements, key_constant, result, kind);
     } else {
       HInstruction* value_instruction =
           Add<HLoadKeyed>(boilerplate_elements, key_constant,
                           static_cast<HValue*>(NULL), kind,
                           ALLOW_RETURN_HOLE);
-      Add<HStoreKeyed>(object_elements, key_constant, value_instruction, kind,
-                       INITIALIZING_STORE);
+      Add<HStoreKeyed>(object_elements, key_constant, value_instruction, kind);
     }
   }
 }
 
 
 void HOptimizedGraphBuilder::VisitThisFunction(ThisFunction* expr) {
   ASSERT(!HasStackOverflow());
   ASSERT(current_block() != NULL);
   ASSERT(current_block()->HasPredecessor());
   HInstruction* instr = BuildThisFunction();
@@ skipping 297 matching lines @@
   HValue* object = Pop();
 
   IfBuilder if_objectisvalue(this);
   HValue* objectisvalue = if_objectisvalue.If<HHasInstanceTypeAndBranch>(
       object, JS_VALUE_TYPE);
   if_objectisvalue.Then();
   {
     // Return the actual value.
     Push(Add<HLoadNamedField>(
             object, objectisvalue,
-            HObjectAccess::ForJSObjectOffset(JSValue::kValueOffset)));
+            HObjectAccess::ForObservableJSObjectPropertyAt(
+                JSValue::kValueOffset)));
     Add<HSimulate>(call->id(), FIXED_SIMULATE);
   }
   if_objectisvalue.Else();
   {
     // If the object is not a value return the object.
     Push(object);
     Add<HSimulate>(call->id(), FIXED_SIMULATE);
   }
   if_objectisvalue.End();
   return ast_context()->ReturnValue(Pop());
@@ skipping 49 matching lines @@
   CHECK_ALIVE(VisitForValue(call->arguments()->at(1)));
   HValue* value = Pop();
   HValue* object = Pop();
 
   // Check if object is a JSValue.
   IfBuilder if_objectisvalue(this);
   if_objectisvalue.If<HHasInstanceTypeAndBranch>(object, JS_VALUE_TYPE);
   if_objectisvalue.Then();
   {
     // Create in-object property store to kValueOffset.
-    Add<HStoreNamedField>(
-        object, HObjectAccess::ForJSObjectOffset(JSValue::kValueOffset),
-        value, INITIALIZING_STORE);
+    Add<HStoreNamedField>(object,
+        HObjectAccess::ForObservableJSObjectPropertyAt(JSValue::kValueOffset),
+        value);
     Add<HSimulate>(call->id(), FIXED_SIMULATE);
   }
   if_objectisvalue.Else();
   {
     // Nothing to do in this case.
     Add<HSimulate>(call->id(), FIXED_SIMULATE);
   }
   if_objectisvalue.End();
   return ast_context()->ReturnValue(value);
 }
@@ skipping 850 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal