Add Smi::Zero and replace all Smi::FromInt(0) calls

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 2f41f83747eb5e31d064679fc09ca9e9d8d134b7..f11e4ef0290f20cb296a18dc1b3183f000c430ca 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -170,10 +170,10 @@ Heap::Heap()
 
   memset(roots_, 0, sizeof(roots_[0]) * kRootListLength);
   set_native_contexts_list(NULL);
-  set_allocation_sites_list(Smi::FromInt(0));
-  set_encountered_weak_collections(Smi::FromInt(0));
-  set_encountered_weak_cells(Smi::FromInt(0));
-  set_encountered_transition_arrays(Smi::FromInt(0));
+  set_allocation_sites_list(Smi::kZero);
+  set_encountered_weak_collections(Smi::kZero);
+  set_encountered_weak_cells(Smi::kZero);
+  set_encountered_transition_arrays(Smi::kZero);
   // Put a dummy entry in the remembered pages so we can find the list the
   // minidump even if there are no real unmapped pages.
   RememberUnmappedPage(NULL, false);
@@ -742,7 +742,7 @@ void Heap::PreprocessStackTraces() {
   }
   // We must not compact the weak fixed list here, as we may be in the middle
   // of writing to it, when the GC triggered. Instead, we reset the root value.
-  set_weak_stack_trace_list(Smi::FromInt(0));
+  set_weak_stack_trace_list(Smi::kZero);
 }
 
 
@@ -2061,7 +2061,7 @@ AllocationResult Heap::AllocatePartialMap(InstanceType instance_type,
                    Map::OwnsDescriptors::encode(true) |
                    Map::ConstructionCounter::encode(Map::kNoSlackTracking);
   reinterpret_cast<Map*>(result)->set_bit_field3(bit_field3);
-  reinterpret_cast<Map*>(result)->set_weak_cell_cache(Smi::FromInt(0));
+  reinterpret_cast<Map*>(result)->set_weak_cell_cache(Smi::kZero);
   return result;
 }
 
@@ -2085,8 +2085,8 @@ AllocationResult Heap::AllocateMap(InstanceType instance_type,
   map->set_code_cache(empty_fixed_array(), SKIP_WRITE_BARRIER);
   map->set_dependent_code(DependentCode::cast(empty_fixed_array()),
                           SKIP_WRITE_BARRIER);
-  map->set_weak_cell_cache(Smi::FromInt(0));
-  map->set_raw_transitions(Smi::FromInt(0));
+  map->set_weak_cell_cache(Smi::kZero);
+  map->set_raw_transitions(Smi::kZero);
   map->set_unused_property_fields(0);
   map->set_instance_descriptors(empty_descriptor_array());
   if (FLAG_unbox_double_fields) {
@@ -2158,7 +2158,7 @@ namespace {
 void FinalizePartialMap(Heap* heap, Map* map) {
   map->set_code_cache(heap->empty_fixed_array());
   map->set_dependent_code(DependentCode::cast(heap->empty_fixed_array()));
-  map->set_raw_transitions(Smi::FromInt(0));
+  map->set_raw_transitions(Smi::kZero);
   map->set_instance_descriptors(heap->empty_descriptor_array());
   if (FLAG_unbox_double_fields) {
     map->set_layout_descriptor(LayoutDescriptor::FastPointerLayout());
@@ -2493,7 +2493,7 @@ AllocationResult Heap::AllocatePropertyCell() {
   PropertyCell* cell = PropertyCell::cast(result);
   cell->set_dependent_code(DependentCode::cast(empty_fixed_array()),
                            SKIP_WRITE_BARRIER);
-  cell->set_property_details(PropertyDetails(Smi::FromInt(0)));
+  cell->set_property_details(PropertyDetails(Smi::kZero));
   cell->set_value(the_hole_value());
   return result;
 }
@@ -2623,8 +2623,7 @@ void Heap::CreateInitialObjects() {
 
   // Initialize the null_value.
   Oddball::Initialize(isolate(), factory->null_value(), "null",
-                      handle(Smi::FromInt(0), isolate()), "object",
-                      Oddball::kNull);
+                      handle(Smi::kZero, isolate()), "object", Oddball::kNull);
 
   // Initialize the_hole_value.
   Oddball::Initialize(isolate(), factory->the_hole_value(), "hole",
@@ -2638,7 +2637,7 @@ void Heap::CreateInitialObjects() {
 
   // Initialize the false_value.
   Oddball::Initialize(isolate(), factory->false_value(), "false",
-                      handle(Smi::FromInt(0), isolate()), "boolean",
+                      handle(Smi::kZero, isolate()), "boolean",
                       Oddball::kFalse);
 
   set_uninitialized_value(
@@ -2684,9 +2683,9 @@ void Heap::CreateInitialObjects() {
   // expanding the dictionary during bootstrapping.
   set_code_stubs(*UnseededNumberDictionary::New(isolate(), 128));
 
-  set_instanceof_cache_function(Smi::FromInt(0));
-  set_instanceof_cache_map(Smi::FromInt(0));
-  set_instanceof_cache_answer(Smi::FromInt(0));
+  set_instanceof_cache_function(Smi::kZero);
+  set_instanceof_cache_map(Smi::kZero);
+  set_instanceof_cache_answer(Smi::kZero);
 
   {
     HandleScope scope(isolate());
@@ -2755,7 +2754,7 @@ void Heap::CreateInitialObjects() {
   set_undefined_cell(*factory->NewCell(factory->undefined_value()));
 
   // The symbol registry is initialized lazily.
-  set_symbol_registry(Smi::FromInt(0));
+  set_symbol_registry(Smi::kZero);
 
   // Microtask queue uses the empty fixed array as a sentinel for "empty".
   // Number of queued microtasks stored in Isolate::pending_microtask_count().
@@ -2803,7 +2802,7 @@ void Heap::CreateInitialObjects() {
     empty_type_feedback_vector->set(TypeFeedbackVector::kMetadataIndex,
                                     empty_fixed_array());
     empty_type_feedback_vector->set(TypeFeedbackVector::kInvocationCountIndex,
-                                    Smi::FromInt(0));
+                                    Smi::kZero);
     set_empty_type_feedback_vector(*empty_type_feedback_vector);
 
     // We use a canonical empty LiteralsArray for all functions that neither
@@ -2847,7 +2846,7 @@ void Heap::CreateInitialObjects() {
       ArrayList::cast(*(factory->NewFixedArray(16, TENURED))));
   weak_new_space_object_to_code_list()->SetLength(0);
 
-  set_script_list(Smi::FromInt(0));
+  set_script_list(Smi::kZero);
 
   Handle<SeededNumberDictionary> slow_element_dictionary =
       SeededNumberDictionary::New(isolate(), 0, TENURED);
@@ -2858,7 +2857,7 @@ void Heap::CreateInitialObjects() {
 
   // Handling of script id generation is in Heap::NextScriptId().
   set_last_script_id(Smi::FromInt(v8::UnboundScript::kNoScriptId));
-  set_next_template_serial_number(Smi::FromInt(0));
+  set_next_template_serial_number(Smi::kZero);
 
   // Allocate the empty script.
   Handle<Script> script = factory->NewScript(factory->empty_string());
@@ -2891,9 +2890,9 @@ void Heap::CreateInitialObjects() {
 
   set_serialized_templates(empty_fixed_array());
 
-  set_weak_stack_trace_list(Smi::FromInt(0));
+  set_weak_stack_trace_list(Smi::kZero);
 
-  set_noscript_shared_function_infos(Smi::FromInt(0));
+  set_noscript_shared_function_infos(Smi::kZero);
 
   // Initialize keyed lookup cache.
   isolate_->keyed_lookup_cache()->Clear();
@@ -3295,7 +3294,7 @@ AllocationResult Heap::AllocateFixedTypedArrayWithExternalPointer(
 
   result->set_map_no_write_barrier(MapForFixedTypedArray(array_type));
   FixedTypedArrayBase* elements = FixedTypedArrayBase::cast(result);
-  elements->set_base_pointer(Smi::FromInt(0), SKIP_WRITE_BARRIER);
+  elements->set_base_pointer(Smi::kZero, SKIP_WRITE_BARRIER);
   elements->set_external_pointer(external_pointer, SKIP_WRITE_BARRIER);
   elements->set_length(length);
   return elements;
@@ -3379,7 +3378,7 @@ AllocationResult Heap::AllocateCode(int object_size, bool immovable) {
   DCHECK(!memory_allocator()->code_range()->valid() ||
          memory_allocator()->code_range()->contains(code->address()) ||
          object_size <= code_space()->AreaSize());
-  code->set_gc_metadata(Smi::FromInt(0));
+  code->set_gc_metadata(Smi::kZero);
   code->set_ic_age(global_ic_age_);
   return code;
 }
@@ -3476,7 +3475,7 @@ void Heap::InitializeJSObjectFromMap(JSObject* obj, FixedArray* properties,
   // TODO(1240798): Initialize the object's body using valid initial values
   // according to the object's initial map.  For example, if the map's
   // instance type is JS_ARRAY_TYPE, the length field should be initialized
-  // to a number (e.g. Smi::FromInt(0)) and the elements initialized to a
+  // to a number (e.g. Smi::kZero) and the elements initialized to a
   // fixed array (e.g. Heap::empty_fixed_array()).  Currently, the object
   // verification code has to cope with (temporarily) invalid objects.  See
   // for example, JSArray::JSArrayVerify).
@@ -5556,8 +5555,8 @@ void Heap::SetStackLimits() {
 }
 
 void Heap::ClearStackLimits() {
-  roots_[kStackLimitRootIndex] = Smi::FromInt(0);
-  roots_[kRealStackLimitRootIndex] = Smi::FromInt(0);
+  roots_[kStackLimitRootIndex] = Smi::kZero;
+  roots_[kRealStackLimitRootIndex] = Smi::kZero;
 }
 
 void Heap::PrintAlloctionsHash() {