A64: Synchronize with r16356.

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 812 matching lines @@
   }
   builder_->set_current_block(first_true_block_);
 }
 
 
 void HGraphBuilder::IfBuilder::Else() {
   ASSERT(did_then_);
   ASSERT(!captured_);
   ASSERT(!finished_);
   last_true_block_ = builder_->current_block();
-  ASSERT(first_true_block_ == NULL || !last_true_block_->IsFinished());
   builder_->set_current_block(first_false_block_);
   did_else_ = true;
 }
 
 
 void HGraphBuilder::IfBuilder::Deopt(const char* reason) {
   ASSERT(did_then_);
   if (did_else_) {
     deopt_else_ = true;
   } else {
@@ skipping 15 matching lines @@
   }
 }
 
 
 void HGraphBuilder::IfBuilder::End() {
   if (!captured_) {
     ASSERT(did_then_);
     if (!did_else_) {
       last_true_block_ = builder_->current_block();
     }
-    if (first_true_block_ == NULL) {
+    if (last_true_block_ == NULL || last_true_block_->IsFinished()) {
+      ASSERT(did_else_);
       // Return on true. Nothing to do, just continue the false block.
-    } else if (first_false_block_ == NULL) {
+    } else if (first_false_block_ == NULL ||
+               (did_else_ && builder_->current_block()->IsFinished())) {
       // Deopt on false. Nothing to do except switching to the true block.
       builder_->set_current_block(last_true_block_);
     } else {
       merge_block_ = builder_->graph()->CreateBasicBlock();
       ASSERT(!finished_);
       if (!did_else_) Else();
       ASSERT(!last_true_block_->IsFinished());
       HBasicBlock* last_false_block = builder_->current_block();
       ASSERT(!last_false_block->IsFinished());
       if (deopt_then_) {
@@ skipping 19 matching lines @@
 HGraphBuilder::LoopBuilder::LoopBuilder(HGraphBuilder* builder,
                                         HValue* context,
                                         LoopBuilder::Direction direction)
     : builder_(builder),
       context_(context),
       direction_(direction),
       finished_(false) {
   header_block_ = builder->CreateLoopHeaderBlock();
   body_block_ = NULL;
   exit_block_ = NULL;
+  exit_trampoline_block_ = NULL;
+  increment_amount_ = builder_->graph()->GetConstant1();
 }
 
 
+HGraphBuilder::LoopBuilder::LoopBuilder(HGraphBuilder* builder,
+                                        HValue* context,
+                                        LoopBuilder::Direction direction,
+                                        HValue* increment_amount)
+    : builder_(builder),
+      context_(context),
+      direction_(direction),
+      finished_(false) {
+  header_block_ = builder->CreateLoopHeaderBlock();
+  body_block_ = NULL;
+  exit_block_ = NULL;
+  exit_trampoline_block_ = NULL;
+  increment_amount_ = increment_amount;
+}
+
+
 HValue* HGraphBuilder::LoopBuilder::BeginBody(
     HValue* initial,
     HValue* terminating,
     Token::Value token) {
   HEnvironment* env = builder_->environment();
   phi_ = header_block_->AddNewPhi(env->values()->length());
   phi_->AddInput(initial);
   env->Push(initial);
   builder_->current_block()->GotoNoSimulate(header_block_);
 
   HEnvironment* body_env = env->Copy();
   HEnvironment* exit_env = env->Copy();
+  // Remove the phi from the expression stack
+  body_env->Pop();
+  exit_env->Pop();
   body_block_ = builder_->CreateBasicBlock(body_env);
   exit_block_ = builder_->CreateBasicBlock(exit_env);
-  // Remove the phi from the expression stack
-  body_env->Pop();
 
   builder_->set_current_block(header_block_);
+  env->Pop();
   HCompareNumericAndBranch* compare =
       new(zone()) HCompareNumericAndBranch(phi_, terminating, token);
   compare->SetSuccessorAt(0, body_block_);
   compare->SetSuccessorAt(1, exit_block_);
   builder_->current_block()->Finish(compare);
 
   builder_->set_current_block(body_block_);
   if (direction_ == kPreIncrement || direction_ == kPreDecrement) {
     HValue* one = builder_->graph()->GetConstant1();
     if (direction_ == kPreIncrement) {
       increment_ = HAdd::New(zone(), context_, phi_, one);
     } else {
       increment_ = HSub::New(zone(), context_, phi_, one);
     }
     increment_->ClearFlag(HValue::kCanOverflow);
     builder_->AddInstruction(increment_);
     return increment_;
   } else {
     return phi_;
   }
 }
 
 
+void HGraphBuilder::LoopBuilder::Break() {
+  if (exit_trampoline_block_ == NULL) {
+    // Its the first time we saw a break.
+    HEnvironment* env = exit_block_->last_environment()->Copy();
+    exit_trampoline_block_ = builder_->CreateBasicBlock(env);
+    exit_block_->GotoNoSimulate(exit_trampoline_block_);
+  }
+
+  builder_->current_block()->GotoNoSimulate(exit_trampoline_block_);
+}
+
+
 void HGraphBuilder::LoopBuilder::EndBody() {
   ASSERT(!finished_);
 
   if (direction_ == kPostIncrement || direction_ == kPostDecrement) {
-    HValue* one = builder_->graph()->GetConstant1();
     if (direction_ == kPostIncrement) {
-      increment_ = HAdd::New(zone(), context_, phi_, one);
+      increment_ = HAdd::New(zone(), context_, phi_, increment_amount_);
     } else {
-      increment_ = HSub::New(zone(), context_, phi_, one);
+      increment_ = HSub::New(zone(), context_, phi_, increment_amount_);
     }
     increment_->ClearFlag(HValue::kCanOverflow);
     builder_->AddInstruction(increment_);
   }
 
   // Push the new increment value on the expression stack to merge into the phi.
   builder_->environment()->Push(increment_);
   HBasicBlock* last_block = builder_->current_block();
   last_block->GotoNoSimulate(header_block_);
   header_block_->loop_information()->RegisterBackEdge(last_block);
 
-  builder_->set_current_block(exit_block_);
-  // Pop the phi from the expression stack
-  builder_->environment()->Pop();
+  if (exit_trampoline_block_ != NULL) {
+    builder_->set_current_block(exit_trampoline_block_);
+  } else {
+    builder_->set_current_block(exit_block_);
+  }
   finished_ = true;
 }
 
 
 HGraph* HGraphBuilder::CreateGraph() {
   graph_ = new(zone()) HGraph(info_);
   if (FLAG_hydrogen_stats) isolate()->GetHStatistics()->Initialize(info_);
   CompilationPhase phase("H_Block building", info_);
   set_current_block(graph()->entry_block());
   if (!BuildGraph()) return NULL;
@@ skipping 198 matching lines @@
                                                 ElementsKind to_kind,
                                                 bool is_jsarray) {
   ASSERT(!IsFastHoleyElementsKind(from_kind) ||
          IsFastHoleyElementsKind(to_kind));
 
   if (AllocationSite::GetMode(from_kind, to_kind) == TRACK_ALLOCATION_SITE) {
     Add<HTrapAllocationMemento>(object);
   }
 
   if (!IsSimpleMapChangeTransition(from_kind, to_kind)) {
-    HInstruction* elements = AddLoadElements(object, NULL);
+    HInstruction* elements = AddLoadElements(object);
 
     HInstruction* empty_fixed_array = Add<HConstant>(
         isolate()->factory()->empty_fixed_array());
 
     IfBuilder if_builder(this);
 
     if_builder.IfNot<HCompareObjectEqAndBranch>(elements, empty_fixed_array);
 
     if_builder.Then();
 
     HInstruction* elements_length = AddLoadFixedArrayLength(elements);
 
     HInstruction* array_length = is_jsarray
         ? Add<HLoadNamedField>(object, 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);
 }
 
 
 HInstruction* HGraphBuilder::BuildUncheckedMonomorphicElementAccess(
-    HValue* object,
+    HValue* checked_object,
     HValue* key,
     HValue* val,
-    HCheckMaps* mapcheck,
     bool is_js_array,
     ElementsKind elements_kind,
     bool is_store,
     LoadKeyedHoleMode load_mode,
     KeyedAccessStoreMode store_mode) {
   ASSERT(!IsExternalArrayElementsKind(elements_kind) || !is_js_array);
   // No GVNFlag is necessary for ElementsKind if there is an explicit dependency
   // on a HElementsTransition instruction. The flag can also be removed if the
   // map to check has FAST_HOLEY_ELEMENTS, since there can be no further
   // ElementsKind transitions. Finally, the dependency can be removed for stores
   // for FAST_ELEMENTS, since a transition to HOLEY elements won't change the
   // generated store code.
   if ((elements_kind == FAST_HOLEY_ELEMENTS) ||
       (elements_kind == FAST_ELEMENTS && is_store)) {
-    if (mapcheck != NULL) {
-      mapcheck->ClearGVNFlag(kDependsOnElementsKind);
-    }
+    checked_object->ClearGVNFlag(kDependsOnElementsKind);
   }
+
   bool fast_smi_only_elements = IsFastSmiElementsKind(elements_kind);
   bool fast_elements = IsFastObjectElementsKind(elements_kind);
-  HValue* elements = AddLoadElements(object, mapcheck);
+  HValue* elements = AddLoadElements(checked_object);
   if (is_store && (fast_elements || fast_smi_only_elements) &&
       store_mode != STORE_NO_TRANSITION_HANDLE_COW) {
     HCheckMaps* check_cow_map = Add<HCheckMaps>(
         elements, isolate()->factory()->fixed_array_map(), top_info());
     check_cow_map->ClearGVNFlag(kDependsOnElementsKind);
   }
   HInstruction* length = NULL;
   if (is_js_array) {
-    length = Add<HLoadNamedField>(object,
-        HObjectAccess::ForArrayLength(elements_kind), mapcheck);
+    length = Add<HLoadNamedField>(
+        checked_object, HObjectAccess::ForArrayLength(elements_kind));
   } else {
     length = AddLoadFixedArrayLength(elements);
   }
   length->set_type(HType::Smi());
   HValue* checked_key = NULL;
   if (IsExternalArrayElementsKind(elements_kind)) {
     if (store_mode == STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS) {
       NoObservableSideEffectsScope no_effects(this);
        HLoadExternalArrayPointer* external_elements =
            Add<HLoadExternalArrayPointer>(elements);
       IfBuilder length_checker(this);
       length_checker.If<HCompareNumericAndBranch>(key, length, Token::LT);
       length_checker.Then();
       IfBuilder negative_checker(this);
       HValue* bounds_check = negative_checker.If<HCompareNumericAndBranch>(
           key, graph()->GetConstant0(), Token::GTE);
       negative_checker.Then();
       HInstruction* result = AddExternalArrayElementAccess(
           external_elements, key, val, bounds_check, elements_kind, is_store);
       negative_checker.ElseDeopt("Negative key encountered");
       length_checker.End();
       return result;
     } else {
       ASSERT(store_mode == STANDARD_STORE);
       checked_key = Add<HBoundsCheck>(key, length);
       HLoadExternalArrayPointer* external_elements =
           Add<HLoadExternalArrayPointer>(elements);
       return AddExternalArrayElementAccess(
           external_elements, checked_key, val,
-          mapcheck, elements_kind, is_store);
+          checked_object, elements_kind, is_store);
     }
   }
   ASSERT(fast_smi_only_elements ||
          fast_elements ||
          IsFastDoubleElementsKind(elements_kind));
 
   // In case val is stored into a fast smi array, assure that the value is a smi
   // before manipulating the backing store. Otherwise the actual store may
   // deopt, leaving the backing store in an invalid state.
   if (is_store && IsFastSmiElementsKind(elements_kind) &&
       !val->type().IsSmi()) {
     val = Add<HForceRepresentation>(val, Representation::Smi());
   }
 
   if (IsGrowStoreMode(store_mode)) {
     NoObservableSideEffectsScope no_effects(this);
-    elements = BuildCheckForCapacityGrow(object, elements, elements_kind,
-                                         length, key, is_js_array);
+    elements = BuildCheckForCapacityGrow(checked_object, elements,
+                                         elements_kind, length, key,
+                                         is_js_array);
     checked_key = key;
   } else {
     checked_key = Add<HBoundsCheck>(key, length);
 
     if (is_store && (fast_elements || fast_smi_only_elements)) {
       if (store_mode == STORE_NO_TRANSITION_HANDLE_COW) {
         NoObservableSideEffectsScope no_effects(this);
-
-        elements = BuildCopyElementsOnWrite(object, elements, elements_kind,
-                                            length);
+        elements = BuildCopyElementsOnWrite(checked_object, elements,
+                                            elements_kind, length);
       } else {
         HCheckMaps* check_cow_map = Add<HCheckMaps>(
             elements, isolate()->factory()->fixed_array_map(),
             top_info());
         check_cow_map->ClearGVNFlag(kDependsOnElementsKind);
       }
     }
   }
-  return AddFastElementAccess(elements, checked_key, val, mapcheck,
+  return AddFastElementAccess(elements, checked_key, val, checked_object,
                               elements_kind, is_store, load_mode, store_mode);
 }
 
 
 HValue* HGraphBuilder::BuildAllocateElements(ElementsKind kind,
                                              HValue* capacity) {
   int elements_size;
   InstanceType instance_type;
 
   if (IsFastDoubleElementsKind(kind)) {
@@ skipping 152 matching lines @@
         UNREACHABLE();
         return NULL;
     }
   }
   // It's an element load (!is_store).
   return Add<HLoadKeyed>(
       elements, checked_key, load_dependency, elements_kind, load_mode);
 }
 
 
-HLoadNamedField* HGraphBuilder::AddLoadElements(HValue* object,
-                                                HValue* typecheck) {
-  return Add<HLoadNamedField>(object,
-                              HObjectAccess::ForElementsPointer(),
-                              typecheck);
+HLoadNamedField* HGraphBuilder::AddLoadElements(HValue* object) {
+  return Add<HLoadNamedField>(object, HObjectAccess::ForElementsPointer());
 }
 
 
 HLoadNamedField* HGraphBuilder::AddLoadFixedArrayLength(HValue* object) {
   return Add<HLoadNamedField>(object,
                               HObjectAccess::ForFixedArrayLength());
 }
 
 
 HValue* HGraphBuilder::BuildNewElementsCapacity(HValue* old_capacity) {
@@ skipping 195 matching lines @@
   }
 
   // Create an allocation site info if requested.
   if (mode == TRACK_ALLOCATION_SITE) {
     BuildCreateAllocationMemento(object, JSArray::kSize, allocation_site);
   }
 
   if (length > 0) {
     // Get hold of the elements array of the boilerplate and setup the
     // elements pointer in the resulting object.
-    HValue* boilerplate_elements = AddLoadElements(boilerplate, NULL);
+    HValue* boilerplate_elements = AddLoadElements(boilerplate);
     HValue* object_elements = Add<HInnerAllocatedObject>(object, elems_offset);
     Add<HStoreNamedField>(object, HObjectAccess::ForElementsPointer(),
                           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, access));
     }
@@ skipping 13 matching lines @@
   return object;
 }
 
 
 void HGraphBuilder::BuildCompareNil(
     HValue* value,
     Handle<Type> type,
     int position,
     HIfContinuation* continuation) {
   IfBuilder if_nil(this, position);
-  bool needs_or = false;
+  bool some_case_handled = false;
+  bool some_case_missing = false;
+
   if (type->Maybe(Type::Null())) {
-    if (needs_or) if_nil.Or();
+    if (some_case_handled) if_nil.Or();
     if_nil.If<HCompareObjectEqAndBranch>(value, graph()->GetConstantNull());
-    needs_or = true;
+    some_case_handled = true;
+  } else {
+    some_case_missing = true;
   }
+
   if (type->Maybe(Type::Undefined())) {
-    if (needs_or) if_nil.Or();
+    if (some_case_handled) if_nil.Or();
     if_nil.If<HCompareObjectEqAndBranch>(value,
                                          graph()->GetConstantUndefined());
-    needs_or = true;
+    some_case_handled = true;
+  } else {
+    some_case_missing = true;
   }
+
   if (type->Maybe(Type::Undetectable())) {
-    if (needs_or) if_nil.Or();
+    if (some_case_handled) if_nil.Or();
     if_nil.If<HIsUndetectableAndBranch>(value);
+    some_case_handled = true;
   } else {
+    some_case_missing = true;
+  }
+
+  if (some_case_missing) {
     if_nil.Then();
     if_nil.Else();
     if (type->NumClasses() == 1) {
       BuildCheckHeapObject(value);
       // For ICs, the map checked below is a sentinel map that gets replaced by
       // the monomorphic map when the code is used as a template to generate a
       // new IC. For optimized functions, there is no sentinel map, the map
       // emitted below is the actual monomorphic map.
       BuildCheckMap(value, type->Classes().Current());
     } else {
@@ skipping 63 matching lines @@
     constructor_function_(constructor_function) {
 }
 
 
 HValue* HGraphBuilder::JSArrayBuilder::EmitMapCode() {
   if (kind_ == GetInitialFastElementsKind()) {
     // No need for a context lookup if the kind_ matches the initial
     // map, because we can just load the map in that case.
     HObjectAccess access = HObjectAccess::ForPrototypeOrInitialMap();
     return builder()->AddInstruction(
-        builder()->BuildLoadNamedField(constructor_function_, access, NULL));
+        builder()->BuildLoadNamedField(constructor_function_, access));
   }
 
   HInstruction* native_context = builder()->BuildGetNativeContext();
   HInstruction* index = builder()->Add<HConstant>(
       static_cast<int32_t>(Context::JS_ARRAY_MAPS_INDEX));
 
   HInstruction* map_array = builder()->Add<HLoadKeyed>(
       native_context, index, static_cast<HValue*>(NULL), FAST_ELEMENTS);
 
   HInstruction* kind_index = builder()->Add<HConstant>(kind_);
 
   return builder()->Add<HLoadKeyed>(
       map_array, kind_index, static_cast<HValue*>(NULL), FAST_ELEMENTS);
 }
 
 
 HValue* HGraphBuilder::JSArrayBuilder::EmitInternalMapCode() {
   // Find the map near the constructor function
   HObjectAccess access = HObjectAccess::ForPrototypeOrInitialMap();
   return builder()->AddInstruction(
-      builder()->BuildLoadNamedField(constructor_function_, access, NULL));
+      builder()->BuildLoadNamedField(constructor_function_, access));
 }
 
 
 HValue* HGraphBuilder::JSArrayBuilder::EstablishAllocationSize(
     HValue* length_node) {
   ASSERT(length_node != NULL);
 
   int base_size = JSArray::kSize;
   if (mode_ == TRACK_ALLOCATION_SITE) {
     base_size += AllocationMemento::kSize;
@@ skipping 2424 matching lines @@
   // TODO(mvstanton): This heuristic is only a temporary solution.  In the
   // end, we want to quit creating allocation site info after a certain number
   // of GCs for a call site.
   AllocationSiteMode mode = AllocationSite::GetMode(
       boilerplate_elements_kind);
 
   // Check whether to use fast or slow deep-copying for boilerplate.
   int data_size = 0;
   int pointer_size = 0;
   int max_properties = kMaxFastLiteralProperties;
-  HCheckMaps* type_check = NULL;
   if (IsFastLiteral(original_boilerplate_object,
                     kMaxFastLiteralDepth,
                     &max_properties,
                     &data_size,
                     &pointer_size)) {
     if (mode == TRACK_ALLOCATION_SITE) {
       pointer_size += AllocationMemento::kSize;
     }
 
     Handle<JSObject> boilerplate_object = DeepCopy(original_boilerplate_object);
@@ skipping 17 matching lines @@
 
     Runtime::FunctionId function_id = (expr->depth() > 1)
         ? Runtime::kCreateArrayLiteral : Runtime::kCreateArrayLiteralShallow;
     literal = Add<HCallRuntime>(isolate()->factory()->empty_string(),
                                 Runtime::FunctionForId(function_id),
                                 3);
 
     // De-opt if elements kind changed from boilerplate_elements_kind.
     Handle<Map> map = Handle<Map>(original_boilerplate_object->map(),
                                   isolate());
-    type_check = Add<HCheckMaps>(literal, map, top_info());
+    literal = Add<HCheckMaps>(literal, map, top_info());
   }
 
   // The array is expected in the bailout environment during computation
   // of the property values and is the value of the entire expression.
   Push(literal);
   // The literal index is on the stack, too.
   Push(Add<HConstant>(expr->literal_index()));
 
   HInstruction* elements = NULL;
 
   for (int i = 0; i < length; i++) {
     Expression* subexpr = subexprs->at(i);
     // If the subexpression is a literal or a simple materialized literal it
     // is already set in the cloned array.
     if (CompileTimeValue::IsCompileTimeValue(subexpr)) continue;
 
     CHECK_ALIVE(VisitForValue(subexpr));
     HValue* value = Pop();
     if (!Smi::IsValid(i)) return Bailout(kNonSmiKeyInArrayLiteral);
 
-    elements = AddLoadElements(literal, type_check);
+    elements = AddLoadElements(literal);
 
     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: {
@@ skipping 41 matching lines @@
 
 
 HCheckMaps* HOptimizedGraphBuilder::AddCheckMap(HValue* object,
                                                 Handle<Map> map) {
   BuildCheckHeapObject(object);
   return Add<HCheckMaps>(object, map, top_info());
 }
 
 
 HInstruction* HOptimizedGraphBuilder::BuildStoreNamedField(
-    HValue* object,
+    HValue* checked_object,
     Handle<String> name,
     HValue* value,
     Handle<Map> map,
     LookupResult* lookup) {
   ASSERT(lookup->IsFound());
   // If the property does not exist yet, we have to check that it wasn't made
   // readonly or turned into a setter by some meanwhile modifications on the
   // prototype chain.
   if (!lookup->IsProperty() && map->prototype()->IsJSReceiver()) {
     Object* proto = map->prototype();
@@ skipping 31 matching lines @@
     if (transition_to_field) {
       // The store requires a mutable HeapNumber to be allocated.
       NoObservableSideEffectsScope no_side_effects(this);
       HInstruction* heap_number_size = Add<HConstant>(HeapNumber::kSize);
       HInstruction* heap_number = Add<HAllocate>(heap_number_size,
           HType::HeapNumber(), isolate()->heap()->GetPretenureMode(),
           HEAP_NUMBER_TYPE);
       AddStoreMapConstant(heap_number, isolate()->factory()->heap_number_map());
       Add<HStoreNamedField>(heap_number, HObjectAccess::ForHeapNumberValue(),
                             value);
-      instr = New<HStoreNamedField>(object, heap_number_access,
-                                           heap_number);
+      instr = New<HStoreNamedField>(checked_object->ActualValue(),
+                                    heap_number_access,
+                                    heap_number);
     } else {
       // Already holds a HeapNumber; load the box and write its value field.
-      HInstruction* heap_number = Add<HLoadNamedField>(object,
+      HInstruction* heap_number = Add<HLoadNamedField>(checked_object,
                                                        heap_number_access);
       heap_number->set_type(HType::HeapNumber());
       instr = New<HStoreNamedField>(heap_number,
                                     HObjectAccess::ForHeapNumberValue(),
                                     value);
     }
   } else {
     // This is a normal store.
-    instr = New<HStoreNamedField>(object, field_access, value);
+    instr = New<HStoreNamedField>(checked_object->ActualValue(),
+                                  field_access,
+                                  value);
   }
 
   if (transition_to_field) {
     Handle<Map> transition(lookup->GetTransitionMapFromMap(*map));
     HConstant* transition_constant = Add<HConstant>(transition);
     instr->SetTransition(transition_constant, top_info());
     // TODO(fschneider): Record the new map type of the object in the IR to
     // enable elimination of redundant checks after the transition store.
     instr->SetGVNFlag(kChangesMaps);
   }
@@ skipping 16 matching lines @@
 
 
 HInstruction* HOptimizedGraphBuilder::BuildStoreNamedMonomorphic(
     HValue* object,
     Handle<String> name,
     HValue* value,
     Handle<Map> map) {
   // Handle a store to a known field.
   LookupResult lookup(isolate());
   if (ComputeLoadStoreField(map, name, &lookup, true)) {
-    AddCheckMap(object, map);
-    return BuildStoreNamedField(object, name, value, map, &lookup);
+    HCheckMaps* checked_object = AddCheckMap(object, map);
+    return BuildStoreNamedField(checked_object, name, value, map, &lookup);
   }
 
   // No luck, do a generic store.
   return BuildStoreNamedGeneric(object, name, value);
 }
 
 
 static bool CanLoadPropertyFromPrototype(Handle<Map> map,
                                          Handle<Name> name,
                                          LookupResult* lookup) {
@@ skipping 37 matching lines @@
       // In-objectness did not match.
       break;
     }
     access = access.WithRepresentation(
         access.representation().generalize(new_access.representation()));
   }
 
   if (count == types->length()) {
     // Everything matched; can use monomorphic load.
     BuildCheckHeapObject(object);
-    HCheckMaps* type_check = Add<HCheckMaps>(object, types);
-    return BuildLoadNamedField(object, access, type_check);
+    HCheckMaps* checked_object = Add<HCheckMaps>(object, types);
+    return BuildLoadNamedField(checked_object, access);
   }
 
   if (count != 0) return NULL;
 
   // Second chance: the property is on the prototype and all maps have the
   // same prototype.
   Handle<Map> map(types->at(0));
   if (!CanLoadPropertyFromPrototype(map, name, &lookup)) return NULL;
 
   Handle<Object> prototype(map->prototype(), isolate());
   for (count = 1; count < types->length(); ++count) {
     Handle<Map> test_map(types->at(count));
     if (!CanLoadPropertyFromPrototype(test_map, name, &lookup)) return NULL;
     if (test_map->prototype() != *prototype) return NULL;
   }
 
   LookupInPrototypes(map, name, &lookup);
   if (!lookup.IsField()) return NULL;
 
   BuildCheckHeapObject(object);
-  HCheckMaps* type_check = Add<HCheckMaps>(object, types);
+  Add<HCheckMaps>(object, types);
 
   Handle<JSObject> holder(lookup.holder());
   Handle<Map> holder_map(holder->map());
-  BuildCheckPrototypeMaps(Handle<JSObject>::cast(prototype), holder);
-  HValue* holder_value = Add<HConstant>(holder);
-  return BuildLoadNamedField(holder_value,
-      HObjectAccess::ForField(holder_map, &lookup, name), type_check);
+  HValue* checked_holder = BuildCheckPrototypeMaps(
+      Handle<JSObject>::cast(prototype), holder);
+  return BuildLoadNamedField(checked_holder,
+      HObjectAccess::ForField(holder_map, &lookup, name));
 }
 
 
 // Returns true if an instance of this map can never find a property with this
 // name in its prototype chain.  This means all prototypes up to the top are
 // fast and don't have the name in them.  It would be good if we could optimize
 // polymorphic loads where the property is sometimes found in the prototype
 // chain.
 static bool PrototypeChainCanNeverResolve(
     Handle<Map> map, Handle<String> name) {
@@ skipping 54 matching lines @@
       HBasicBlock* if_false = graph()->CreateBasicBlock();
       HCompareMap* compare =
           new(zone()) HCompareMap(object, map,  if_true, if_false);
       current_block()->Finish(compare);
 
       set_current_block(if_true);
 
       // TODO(verwaest): Merge logic with BuildLoadNamedMonomorphic.
       if (lookup.IsField()) {
         HObjectAccess access = HObjectAccess::ForField(map, &lookup, name);
-        HLoadNamedField* load = BuildLoadNamedField(object, access, compare);
+        HLoadNamedField* load = BuildLoadNamedField(compare, access);
         load->set_position(expr->position());
         AddInstruction(load);
         if (!ast_context()->IsEffect()) Push(load);
       } else if (lookup.IsConstant()) {
         Handle<Object> constant(lookup.GetConstantFromMap(*map), isolate());
         HConstant* hconstant = Add<HConstant>(constant);
         if (!ast_context()->IsEffect()) Push(hconstant);
       } else {
         ASSERT(!lookup.IsFound());
         if (map->prototype()->IsJSObject()) {
@@ skipping 79 matching lines @@
     } else if (access.IsInobject() != new_access.IsInobject()) {
       // In-objectness did not match.
       break;
     }
   }
 
   if (count != types->length()) return false;
 
   // Everything matched; can use monomorphic store.
   BuildCheckHeapObject(object);
-  Add<HCheckMaps>(object, types);
+  HCheckMaps* checked_object = Add<HCheckMaps>(object, types);
   HInstruction* store;
   CHECK_ALIVE_OR_RETURN(
       store = BuildStoreNamedField(
-          object, name, store_value, types->at(count - 1), &lookup),
+          checked_object, name, store_value, types->at(count - 1), &lookup),
       true);
   if (!ast_context()->IsEffect()) Push(result_value);
   store->set_position(position);
   AddInstruction(store);
   Add<HSimulate>(assignment_id);
   if (!ast_context()->IsEffect()) Drop(1);
   ast_context()->ReturnValue(result_value);
   return true;
 }
 
@@ skipping 28 matching lines @@
       ++count;
       HBasicBlock* if_true = graph()->CreateBasicBlock();
       HBasicBlock* if_false = graph()->CreateBasicBlock();
       HCompareMap* compare =
           new(zone()) HCompareMap(object, map,  if_true, if_false);
       current_block()->Finish(compare);
 
       set_current_block(if_true);
       HInstruction* instr;
       CHECK_ALIVE(instr = BuildStoreNamedField(
-          object, name, store_value, map, &lookup));
+          compare, name, store_value, map, &lookup));
       instr->set_position(position);
       // Goto will add the HSimulate for the store.
       AddInstruction(instr);
       if (!ast_context()->IsEffect()) Push(result_value);
       current_block()->Goto(join);
 
       set_current_block(if_false);
     }
   }
 
@@ skipping 499 matching lines @@
   HValue* value = environment()->Pop();
   HThrow* instr = Add<HThrow>(value);
   instr->set_position(expr->position());
   Add<HSimulate>(expr->id());
   current_block()->FinishExit(new(zone()) HAbnormalExit);
   set_current_block(NULL);
 }
 
 
 HLoadNamedField* HGraphBuilder::BuildLoadNamedField(HValue* object,
-                                                    HObjectAccess access,
-                                                    HValue* typecheck) {
+                                                    HObjectAccess access) {
   if (FLAG_track_double_fields && access.representation().IsDouble()) {
     // load the heap number
     HLoadNamedField* heap_number = Add<HLoadNamedField>(
         object, access.WithRepresentation(Representation::Tagged()));
     heap_number->set_type(HType::HeapNumber());
     // load the double value from it
-    return New<HLoadNamedField>(heap_number,
-                                HObjectAccess::ForHeapNumberValue(),
-                                typecheck);
+    return New<HLoadNamedField>(
+        heap_number, HObjectAccess::ForHeapNumberValue());
   }
-  return New<HLoadNamedField>(object, access, typecheck);
+  return New<HLoadNamedField>(object, access);
 }
 
 
 HInstruction* HGraphBuilder::BuildLoadStringLength(HValue* object,
-                                                   HValue* typecheck) {
+                                                   HValue* checked_string) {
   if (FLAG_fold_constants && object->IsConstant()) {
     HConstant* constant = HConstant::cast(object);
     if (constant->HasStringValue()) {
       return New<HConstant>(constant->StringValue()->length());
     }
   }
-  return BuildLoadNamedField(
-      object, HObjectAccess::ForStringLength(), typecheck);
+  return BuildLoadNamedField(checked_string, HObjectAccess::ForStringLength());
 }
 
 
 HInstruction* HOptimizedGraphBuilder::BuildLoadNamedGeneric(
     HValue* object,
     Handle<String> name,
     Property* expr) {
   if (expr->IsUninitialized()) {
     Add<HDeoptimize>("Insufficient feedback for generic named load",
                      Deoptimizer::SOFT);
@@ skipping 18 matching lines @@
     HValue* object,
     Handle<String> name,
     Property* expr,
     Handle<Map> map) {
   // Handle a load from a known field.
   ASSERT(!map->is_dictionary_map());
 
   // Handle access to various length properties
   if (name->Equals(isolate()->heap()->length_string())) {
     if (map->instance_type() == JS_ARRAY_TYPE) {
-      HCheckMaps* type_check = AddCheckMap(object, map);
-      return New<HLoadNamedField>(object,
-          HObjectAccess::ForArrayLength(map->elements_kind()), type_check);
+      HCheckMaps* checked_object = AddCheckMap(object, map);
+      return New<HLoadNamedField>(
+          checked_object, HObjectAccess::ForArrayLength(map->elements_kind()));
     }
   }
 
   LookupResult lookup(isolate());
   map->LookupDescriptor(NULL, *name, &lookup);
   if (lookup.IsField()) {
-    HCheckMaps* type_check = AddCheckMap(object, map);
-    return BuildLoadNamedField(object,
-        HObjectAccess::ForField(map, &lookup, name), type_check);
+    HCheckMaps* checked_object = AddCheckMap(object, map);
+    return BuildLoadNamedField(
+        checked_object, HObjectAccess::ForField(map, &lookup, name));
   }
 
   // Handle a load of a constant known function.
   if (lookup.IsConstant()) {
     AddCheckMap(object, map);
     Handle<Object> constant(lookup.GetConstantFromMap(*map), isolate());
     return New<HConstant>(constant);
   }
 
   // Handle a load from a known field somewhere in the prototype chain.
   LookupInPrototypes(map, name, &lookup);
   if (lookup.IsField()) {
     Handle<JSObject> prototype(JSObject::cast(map->prototype()));
     Handle<JSObject> holder(lookup.holder());
     Handle<Map> holder_map(holder->map());
-    HCheckMaps* type_check = AddCheckMap(object, map);
-    BuildCheckPrototypeMaps(prototype, holder);
-    HValue* holder_value = Add<HConstant>(holder);
-    return BuildLoadNamedField(holder_value,
-        HObjectAccess::ForField(holder_map, &lookup, name), type_check);
+    AddCheckMap(object, map);
+    HValue* checked_holder = BuildCheckPrototypeMaps(prototype, holder);
+    return BuildLoadNamedField(
+        checked_holder, HObjectAccess::ForField(holder_map, &lookup, name));
   }
 
   // Handle a load of a constant function somewhere in the prototype chain.
   if (lookup.IsConstant()) {
     Handle<JSObject> prototype(JSObject::cast(map->prototype()));
     Handle<JSObject> holder(lookup.holder());
     Handle<Map> holder_map(holder->map());
     AddCheckMap(object, map);
     BuildCheckPrototypeMaps(prototype, holder);
     Handle<Object> constant(lookup.GetConstantFromMap(*holder_map), isolate());
     return New<HConstant>(constant);
   }
 
   // No luck, do a generic load.
   return BuildLoadNamedGeneric(object, name, expr);
 }
 
 
 HInstruction* HOptimizedGraphBuilder::BuildLoadKeyedGeneric(HValue* object,
                                                             HValue* key) {
   HValue* context = environment()->context();
   return new(zone()) HLoadKeyedGeneric(context, object, key);
 }
 
 
-HInstruction* HOptimizedGraphBuilder::BuildMonomorphicElementAccess(
-    HValue* object,
-    HValue* key,
-    HValue* val,
-    HValue* dependency,
-    Handle<Map> map,
-    bool is_store,
-    KeyedAccessStoreMode store_mode) {
-  HCheckMaps* mapcheck = Add<HCheckMaps>(object, map, top_info(), dependency);
-  if (dependency) {
-    mapcheck->ClearGVNFlag(kDependsOnElementsKind);
-  }
-
+LoadKeyedHoleMode HOptimizedGraphBuilder::BuildKeyedHoleMode(Handle<Map> map) {
   // Loads from a "stock" fast holey double arrays can elide the hole check.
   LoadKeyedHoleMode load_mode = NEVER_RETURN_HOLE;
   if (*map == isolate()->get_initial_js_array_map(FAST_HOLEY_DOUBLE_ELEMENTS) &&
       isolate()->IsFastArrayConstructorPrototypeChainIntact()) {
     Handle<JSObject> prototype(JSObject::cast(map->prototype()), isolate());
     Handle<JSObject> object_prototype = isolate()->initial_object_prototype();
     BuildCheckPrototypeMaps(prototype, object_prototype);
     load_mode = ALLOW_RETURN_HOLE;
     graph()->MarkDependsOnEmptyArrayProtoElements();
   }
 
-  return BuildUncheckedMonomorphicElementAccess(
-      object, key, val,
-      mapcheck, map->instance_type() == JS_ARRAY_TYPE,
-      map->elements_kind(), is_store, load_mode, store_mode);
+  return load_mode;
 }
 
 
+HInstruction* HOptimizedGraphBuilder::BuildMonomorphicElementAccess(
+    HValue* object,
+    HValue* key,
+    HValue* val,
+    HValue* dependency,
+    Handle<Map> map,
+    bool is_store,
+    KeyedAccessStoreMode store_mode) {
+  HCheckMaps* checked_object = Add<HCheckMaps>(object, map, top_info(),
+                                               dependency);
+  if (dependency) {
+    checked_object->ClearGVNFlag(kDependsOnElementsKind);
+  }
+
+  LoadKeyedHoleMode load_mode = BuildKeyedHoleMode(map);
+  return BuildUncheckedMonomorphicElementAccess(
+      checked_object, key, val,
+      map->instance_type() == JS_ARRAY_TYPE,
+      map->elements_kind(), is_store,
+      load_mode, store_mode);
+}
+
+
 HInstruction* HOptimizedGraphBuilder::TryBuildConsolidatedElementLoad(
     HValue* object,
     HValue* key,
     HValue* val,
     SmallMapList* maps) {
   // For polymorphic loads of similar elements kinds (i.e. all tagged or all
   // double), always use the "worst case" code without a transition.  This is
   // much faster than transitioning the elements to the worst case, trading a
   // HTransitionElements for a HCheckMaps, and avoiding mutation of the array.
   bool has_double_maps = false;
   bool has_smi_or_object_maps = false;
   bool has_js_array_access = false;
   bool has_non_js_array_access = false;
+  bool has_seen_holey_elements = false;
   Handle<Map> most_general_consolidated_map;
   for (int i = 0; i < maps->length(); ++i) {
     Handle<Map> map = maps->at(i);
     // Don't allow mixing of JSArrays with JSObjects.
     if (map->instance_type() == JS_ARRAY_TYPE) {
       if (has_non_js_array_access) return NULL;
       has_js_array_access = true;
     } else if (has_js_array_access) {
       return NULL;
     } else {
       has_non_js_array_access = true;
     }
     // Don't allow mixed, incompatible elements kinds.
     if (map->has_fast_double_elements()) {
       if (has_smi_or_object_maps) return NULL;
       has_double_maps = true;
     } else if (map->has_fast_smi_or_object_elements()) {
       if (has_double_maps) return NULL;
       has_smi_or_object_maps = true;
     } else {
       return NULL;
     }
+    // Remember if we've ever seen holey elements.
+    if (IsHoleyElementsKind(map->elements_kind())) {
+      has_seen_holey_elements = true;
+    }
     // Remember the most general elements kind, the code for its load will
     // properly handle all of the more specific cases.
     if ((i == 0) || IsMoreGeneralElementsKindTransition(
             most_general_consolidated_map->elements_kind(),
             map->elements_kind())) {
       most_general_consolidated_map = map;
     }
   }
   if (!has_double_maps && !has_smi_or_object_maps) return NULL;
 
-  HCheckMaps* check_maps = Add<HCheckMaps>(object, maps);
+  HCheckMaps* checked_object = Add<HCheckMaps>(object, maps);
+  // FAST_ELEMENTS is considered more general than FAST_HOLEY_SMI_ELEMENTS.
+  // If we've seen both, the consolidated load must use FAST_HOLEY_ELEMENTS.
+  ElementsKind consolidated_elements_kind = has_seen_holey_elements
+      ? GetHoleyElementsKind(most_general_consolidated_map->elements_kind())
+      : most_general_consolidated_map->elements_kind();
   HInstruction* instr = BuildUncheckedMonomorphicElementAccess(
-      object, key, val, check_maps,
+      checked_object, key, val,
       most_general_consolidated_map->instance_type() == JS_ARRAY_TYPE,
-      most_general_consolidated_map->elements_kind(),
+      consolidated_elements_kind,
       false, NEVER_RETURN_HOLE, STANDARD_STORE);
   return instr;
 }
 
 
 HValue* HOptimizedGraphBuilder::HandlePolymorphicElementAccess(
     HValue* object,
     HValue* key,
     HValue* val,
     Expression* prop,
@@ skipping 66 matching lines @@
     } else {
       instr = BuildMonomorphicElementAccess(
           object, key, val, transition, untransitionable_map, is_store,
           store_mode);
     }
     *has_side_effects |= instr->HasObservableSideEffects();
     if (position != RelocInfo::kNoPosition) instr->set_position(position);
     return is_store ? NULL : instr;
   }
 
-  HInstruction* checkspec =
-      AddInstruction(HCheckInstanceType::NewIsSpecObject(object, zone()));
   HBasicBlock* join = graph()->CreateBasicBlock();
 
-  HInstruction* elements = AddLoadElements(object, checkspec);
-
   for (int i = 0; i < untransitionable_maps.length(); ++i) {
     Handle<Map> map = untransitionable_maps[i];
     ElementsKind elements_kind = map->elements_kind();
     HBasicBlock* this_map = graph()->CreateBasicBlock();
     HBasicBlock* other_map = graph()->CreateBasicBlock();
     HCompareMap* mapcompare =
         new(zone()) HCompareMap(object, map, this_map, other_map);
     current_block()->Finish(mapcompare);
 
     set_current_block(this_map);
-    HInstruction* checked_key = NULL;
     HInstruction* access = NULL;
-    if (IsFastElementsKind(elements_kind)) {
-      if (is_store && !IsFastDoubleElementsKind(elements_kind)) {
-        Add<HCheckMaps>(
-            elements, isolate()->factory()->fixed_array_map(),
-            top_info(), mapcompare);
-      }
-      if (map->instance_type() == JS_ARRAY_TYPE) {
-        HInstruction* length = Add<HLoadNamedField>(
-            object, HObjectAccess::ForArrayLength(elements_kind), mapcompare);
-        checked_key = Add<HBoundsCheck>(key, length);
-      } else {
-        HInstruction* length = AddLoadFixedArrayLength(elements);
-        checked_key = Add<HBoundsCheck>(key, length);
-      }
-      access = AddFastElementAccess(
-          elements, checked_key, val, mapcompare,
-          elements_kind, is_store, NEVER_RETURN_HOLE, STANDARD_STORE);
-    } else if (IsDictionaryElementsKind(elements_kind)) {
-      if (is_store) {
-        access = AddInstruction(BuildStoreKeyedGeneric(object, key, val));
-      } else {
-        access = AddInstruction(BuildLoadKeyedGeneric(object, key));
-      }
+    if (IsDictionaryElementsKind(elements_kind)) {
+      access = is_store
+          ? AddInstruction(BuildStoreKeyedGeneric(object, key, val))
+          : AddInstruction(BuildLoadKeyedGeneric(object, key));
     } else {
-      ASSERT(IsExternalArrayElementsKind(elements_kind));
-      HInstruction* length = AddLoadFixedArrayLength(elements);
-      checked_key = Add<HBoundsCheck>(key, length);
-      HLoadExternalArrayPointer* external_elements =
-          Add<HLoadExternalArrayPointer>(elements);
-      access = AddExternalArrayElementAccess(
-          external_elements, checked_key, val,
-          mapcompare, elements_kind, is_store);
+      ASSERT(IsFastElementsKind(elements_kind) ||
+             IsExternalArrayElementsKind(elements_kind));
+      LoadKeyedHoleMode load_mode = BuildKeyedHoleMode(map);
+      // Happily, mapcompare is a checked object.
+      access = BuildUncheckedMonomorphicElementAccess(
+          mapcompare, key, val,
+          map->instance_type() == JS_ARRAY_TYPE,
+          elements_kind, is_store,
+          load_mode,
+          store_mode);
     }
     *has_side_effects |= access->HasObservableSideEffects();
     // The caller will use has_side_effects and add a correct Simulate.
     access->SetFlag(HValue::kHasNoObservableSideEffects);
     if (position != RelocInfo::kNoPosition) access->set_position(position);
     if (!is_store) {
       Push(access);
     }
     NoObservableSideEffectsScope scope(this);
     current_block()->GotoNoSimulate(join);
@@ skipping 232 matching lines @@
         Drop(1);
       }
     }
     return ast_context()->ReturnValue(load);
   }
   instr->set_position(expr->position());
   return ast_context()->ReturnInstruction(instr, expr->id());
 }
 
 
-void HGraphBuilder::BuildConstantMapCheck(Handle<JSObject> constant,
-                                          CompilationInfo* info) {
+HInstruction* HGraphBuilder::BuildConstantMapCheck(Handle<JSObject> constant,
+                                                   CompilationInfo* info) {
   HConstant* constant_value = New<HConstant>(constant);
 
   if (constant->map()->CanOmitMapChecks()) {
     constant->map()->AddDependentCompilationInfo(
         DependentCode::kPrototypeCheckGroup, info);
-    return;
+    return constant_value;
   }
 
   AddInstruction(constant_value);
   HCheckMaps* check =
       Add<HCheckMaps>(constant_value, handle(constant->map()), info);
   check->ClearGVNFlag(kDependsOnElementsKind);
+  return check;
 }
 
 
-void HGraphBuilder::BuildCheckPrototypeMaps(Handle<JSObject> prototype,
-                                            Handle<JSObject> holder) {
-  BuildConstantMapCheck(prototype, top_info());
+HInstruction* HGraphBuilder::BuildCheckPrototypeMaps(Handle<JSObject> prototype,
+                                                     Handle<JSObject> holder) {
   while (!prototype.is_identical_to(holder)) {
+    BuildConstantMapCheck(prototype, top_info());
     prototype = handle(JSObject::cast(prototype->GetPrototype()));
-    BuildConstantMapCheck(prototype, top_info());
   }
+
+  HInstruction* checked_object = BuildConstantMapCheck(prototype, top_info());
+  if (!checked_object->IsLinked()) AddInstruction(checked_object);
+  return checked_object;
 }
 
 
 void HOptimizedGraphBuilder::AddCheckPrototypeMaps(Handle<JSObject> holder,
                                                    Handle<Map> receiver_map) {
   if (!holder.is_null()) {
     Handle<JSObject> prototype(JSObject::cast(receiver_map->prototype()));
     BuildCheckPrototypeMaps(prototype, holder);
   }
 }
@@ skipping 805 matching lines @@
             HInstruction* sqrt =
                 HUnaryMathOperation::New(zone(), context, left, kMathPowHalf);
             AddInstruction(sqrt);
             // MathPowHalf doesn't have side effects so there's no need for
             // an environment simulation here.
             ASSERT(!sqrt->HasObservableSideEffects());
             result = HDiv::New(zone(), context, one, sqrt);
           } else if (exponent == 2.0) {
             result = HMul::New(zone(), context, left, left);
           }
-        } else if (right->EqualsInteger32Constant(2)) {
-          result = HMul::New(zone(), context, left, left);
         }
 
         if (result == NULL) {
           result = HPower::New(zone(), context, left, right);
         }
         ast_context()->ReturnInstruction(result, expr->id());
         return true;
       }
       break;
     case kMathRandom:
@@ skipping 658 matching lines @@
     }
     Push(number_input);
   }
 
   // The addition has no side effects, so we do not need
   // to simulate the expression stack after this instruction.
   // Any later failures deopt to the load of the input or earlier.
   HConstant* delta = (expr->op() == Token::INC)
       ? graph()->GetConstant1()
       : graph()->GetConstantMinus1();
-  HInstruction* instr = Add<HAdd>(Top(), delta);
+  HInstruction* instr = AddUncasted<HAdd>(Top(), delta);
+  if (instr->IsAdd()) {
+    HAdd* add = HAdd::cast(instr);
+    add->set_observed_input_representation(1, rep);
+    add->set_observed_input_representation(2, Representation::Smi());
+  }
   instr->SetFlag(HInstruction::kCannotBeTagged);
   instr->ClearAllSideEffects();
   return instr;
 }
 
 
 void HOptimizedGraphBuilder::VisitCountOperation(CountOperation* expr) {
   ASSERT(!HasStackOverflow());
   ASSERT(current_block() != NULL);
   ASSERT(current_block()->HasPredecessor());
@@ skipping 691 matching lines @@
 
 void HOptimizedGraphBuilder::HandleLiteralCompareNil(CompareOperation* expr,
                                                      Expression* sub_expr,
                                                      NilValue nil) {
   ASSERT(!HasStackOverflow());
   ASSERT(current_block() != NULL);
   ASSERT(current_block()->HasPredecessor());
   ASSERT(expr->op() == Token::EQ || expr->op() == Token::EQ_STRICT);
   CHECK_ALIVE(VisitForValue(sub_expr));
   HValue* value = Pop();
-  HIfContinuation continuation;
   if (expr->op() == Token::EQ_STRICT) {
-    IfBuilder if_nil(this);
-    if_nil.If<HCompareObjectEqAndBranch>(
-        value, (nil == kNullValue) ? graph()->GetConstantNull()
-                                   : graph()->GetConstantUndefined());
-    if_nil.Then();
-    if_nil.Else();
-    if_nil.CaptureContinuation(&continuation);
+    HConstant* nil_constant = nil == kNullValue
+        ? graph()->GetConstantNull()
+        : graph()->GetConstantUndefined();
+    HCompareObjectEqAndBranch* instr =
+        New<HCompareObjectEqAndBranch>(value, nil_constant);
+    instr->set_position(expr->position());
+    return ast_context()->ReturnControl(instr, expr->id());
+  } else {
+    ASSERT_EQ(Token::EQ, expr->op());
+    Handle<Type> type = expr->combined_type()->Is(Type::None())
+        ? handle(Type::Any(), isolate_)
+        : expr->combined_type();
+    HIfContinuation continuation;
+    BuildCompareNil(value, type, expr->position(), &continuation);
     return ast_context()->ReturnContinuation(&continuation, expr->id());
   }
-  Handle<Type> type = expr->combined_type()->Is(Type::None())
-      ? handle(Type::Any(), isolate_) : expr->combined_type();
-  BuildCompareNil(value, type, expr->position(), &continuation);
-  return ast_context()->ReturnContinuation(&continuation, expr->id());
 }
 
 
 HInstruction* HOptimizedGraphBuilder::BuildThisFunction() {
   // If we share optimized code between different closures, the
   // this-function is not a constant, except inside an inlined body.
   if (function_state()->outer() != NULL) {
       return New<HConstant>(
           function_state()->compilation_info()->closure());
   } else {
@@ skipping 1318 matching lines @@
   } else {
     CodeStub::Major major_key = info->code_stub()->MajorKey();
     PrintStringProperty("name", CodeStub::MajorName(major_key, false));
     PrintStringProperty("method", "stub");
   }
   PrintLongProperty("date", static_cast<int64_t>(OS::TimeCurrentMillis()));
 }
 
 
 void HTracer::TraceLithium(const char* name, LChunk* chunk) {
-  ASSERT(!FLAG_parallel_recompilation);
+  ASSERT(!FLAG_concurrent_recompilation);
   AllowHandleDereference allow_deref;
   AllowDeferredHandleDereference allow_deferred_deref;
   Trace(name, chunk->graph(), chunk);
 }
 
 
 void HTracer::TraceHydrogen(const char* name, HGraph* graph) {
-  ASSERT(!FLAG_parallel_recompilation);
+  ASSERT(!FLAG_concurrent_recompilation);
   AllowHandleDereference allow_deref;
   AllowDeferredHandleDereference allow_deferred_deref;
   Trace(name, graph, NULL);
 }
 
 
 void HTracer::Trace(const char* name, HGraph* graph, LChunk* chunk) {
   Tag tag(this, "cfg");
   PrintStringProperty("name", name);
   const ZoneList<HBasicBlock*>* blocks = graph->blocks();
@@ skipping 266 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal