Generate StoreGlobal stubs with Hydrogen

src/objects.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 616 matching lines @@
   ASSERT(!value->IsPropertyCell() && !value->IsCell());
   return value;
 }
 
 
 Object* JSObject::SetNormalizedProperty(LookupResult* result, Object* value) {
   ASSERT(!HasFastProperties());
   if (IsGlobalObject()) {
     PropertyCell* cell = PropertyCell::cast(
         property_dictionary()->ValueAt(result->GetDictionaryEntry()));
-    cell->set_value(value);
+    cell->set_value_infer_type(value);
   } else {
     property_dictionary()->ValueAtPut(result->GetDictionaryEntry(), value);
   }
   return value;
 }
 
 
 Handle<Object> JSObject::SetNormalizedProperty(Handle<JSObject> object,
                                                Handle<Name> key,
                                                Handle<Object> value,
                                                PropertyDetails details) {
   CALL_HEAP_FUNCTION(object->GetIsolate(),
                      object->SetNormalizedProperty(*key, *value, details),
                      Object);
 }
 
 
 MaybeObject* JSObject::SetNormalizedProperty(Name* name,
                                              Object* value,
                                              PropertyDetails details) {
   ASSERT(!HasFastProperties());
   int entry = property_dictionary()->FindEntry(name);
   if (entry == NameDictionary::kNotFound) {
     Object* store_value = value;
     if (IsGlobalObject()) {
       Heap* heap = name->GetHeap();
-      MaybeObject* maybe_store_value =
-          heap->AllocatePropertyCell(value);
+      MaybeObject* maybe_store_value = heap->AllocatePropertyCell(value);
       if (!maybe_store_value->ToObject(&store_value)) return maybe_store_value;
     }
     Object* dict;
     { MaybeObject* maybe_dict =
           property_dictionary()->Add(name, store_value, details);
       if (!maybe_dict->ToObject(&dict)) return maybe_dict;
     }
     set_properties(NameDictionary::cast(dict));
     return value;
   }
 
   PropertyDetails original_details = property_dictionary()->DetailsAt(entry);
   int enumeration_index;
   // Preserve the enumeration index unless the property was deleted.
   if (original_details.IsDeleted()) {
     enumeration_index = property_dictionary()->NextEnumerationIndex();
     property_dictionary()->SetNextEnumerationIndex(enumeration_index + 1);
   } else {
     enumeration_index = original_details.dictionary_index();
     ASSERT(enumeration_index > 0);
   }
 
   details = PropertyDetails(
       details.attributes(), details.type(), enumeration_index);
 
   if (IsGlobalObject()) {
     PropertyCell* cell =
         PropertyCell::cast(property_dictionary()->ValueAt(entry));
-    cell->set_value(value);
+    cell->set_value_infer_type(value);
     // Please note we have to update the property details.
     property_dictionary()->DetailsAtPut(entry, details);
   } else {
     property_dictionary()->SetEntry(entry, name, value, details);
   }
   return value;
 }
 
 
 MaybeObject* JSObject::DeleteNormalizedProperty(Name* name, DeleteMode mode) {
@@ skipping 11 matching lines @@
         // from the DontDelete cell without checking if it contains
         // the hole value.
         Map* new_map;
         MaybeObject* maybe_new_map = map()->CopyDropDescriptors();
         if (!maybe_new_map->To(&new_map)) return maybe_new_map;
 
         ASSERT(new_map->is_dictionary_map());
         set_map(new_map);
       }
       PropertyCell* cell = PropertyCell::cast(dictionary->ValueAt(entry));
-      cell->set_value(cell->GetHeap()->the_hole_value());
+      cell->set_value_infer_type(cell->GetHeap()->the_hole_value());
       dictionary->DetailsAtPut(entry, details.AsDeleted());
     } else {
       Object* deleted = dictionary->DeleteProperty(entry, mode);
       if (deleted == GetHeap()->true_value()) {
         FixedArray* new_properties = NULL;
         MaybeObject* maybe_properties = dictionary->Shrink(name);
         if (!maybe_properties->To(&new_properties)) {
           return maybe_properties;
         }
         set_properties(new_properties);
@@ skipping 1186 matching lines @@
                                        Object* value,
                                        PropertyAttributes attributes) {
   ASSERT(!HasFastProperties());
   NameDictionary* dict = property_dictionary();
   Object* store_value = value;
   if (IsGlobalObject()) {
     // In case name is an orphaned property reuse the cell.
     int entry = dict->FindEntry(name);
     if (entry != NameDictionary::kNotFound) {
       store_value = dict->ValueAt(entry);
-      PropertyCell::cast(store_value)->set_value(value);
+      PropertyCell::cast(store_value)->set_value_infer_type(value);
       // Assign an enumeration index to the property and update
       // SetNextEnumerationIndex.
       int index = dict->NextEnumerationIndex();
       PropertyDetails details = PropertyDetails(attributes, NORMAL, index);
       dict->SetNextEnumerationIndex(index + 1);
       dict->SetEntry(entry, name, store_value, details);
       return value;
     }
     Heap* heap = GetHeap();
     { MaybeObject* maybe_store_value =
           heap->AllocatePropertyCell(value);
       if (!maybe_store_value->ToObject(&store_value)) return maybe_store_value;
     }
-    PropertyCell::cast(store_value)->set_value(value);
+    PropertyCell::cast(store_value)->set_value_infer_type(value);
   }
   PropertyDetails details = PropertyDetails(attributes, NORMAL, 0);
   Object* result;
   { MaybeObject* maybe_result = dict->Add(name, store_value, details);
     if (!maybe_result->ToObject(&result)) return maybe_result;
   }
   if (dict != result) set_properties(NameDictionary::cast(result));
   return value;
 }
 
@@ skipping 8146 matching lines @@
   return statement_position;
 }
 
 
 SafepointEntry Code::GetSafepointEntry(Address pc) {
   SafepointTable table(this);
   return table.FindEntry(pc);
 }
 
 
-Map* Code::FindFirstMap() {
+Object* Code::FindNthObject(int n, Map* match_map) {
   ASSERT(is_inline_cache_stub());
   DisallowHeapAllocation no_allocation;
   int mask = RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT);
   for (RelocIterator it(this, mask); !it.done(); it.next()) {
     RelocInfo* info = it.rinfo();
     Object* object = info->target_object();
-    if (object->IsMap()) return Map::cast(object);
+    if (object->IsHeapObject()) {
+      if (HeapObject::cast(object)->map() == match_map) {
+        if (--n == 0) return object;
+      }
+    }
   }
   return NULL;
 }
 
 
-void Code::ReplaceFirstMap(Map* replace_with) {
+Map* Code::FindFirstMap() {
+  Object* result = FindNthObject(1, GetHeap()->meta_map());
+  if (result == NULL) return NULL;

[rossberg, 2013/06/25 10:47:38]

Nit: could avoid the extra return using ?:

[danno, 2013/06/28 13:56:05]

Done.

+  return Map::cast(result);
+}
+
+
+void Code::ReplaceNthObject(int n,
+                            Map* match_map,
+                            Object* replace_with) {
   ASSERT(is_inline_cache_stub());
   DisallowHeapAllocation no_allocation;
   int mask = RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT);
   for (RelocIterator it(this, mask); !it.done(); it.next()) {
     RelocInfo* info = it.rinfo();
     Object* object = info->target_object();
-    if (object->IsMap()) {
-      info->set_target_object(replace_with);
-      return;
+    if (object->IsHeapObject()) {
+      if (HeapObject::cast(object)->map() == match_map) {
+        if (--n == 0) {
+          info->set_target_object(replace_with);
+          return;
+        }
+      }
     }
   }
   UNREACHABLE();
 }
 
 
 void Code::FindAllMaps(MapHandleList* maps) {
   ASSERT(is_inline_cache_stub());
   DisallowHeapAllocation no_allocation;
   int mask = RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT);
   for (RelocIterator it(this, mask); !it.done(); it.next()) {
     RelocInfo* info = it.rinfo();
     Object* object = info->target_object();
     if (object->IsMap()) maps->Add(Handle<Map>(Map::cast(object)));
   }
 }
 
 
+void Code::ReplaceFirstMap(Map* replace_with) {
+  ReplaceNthObject(1, GetHeap()->meta_map(), replace_with);
+}
+
+
 Code* Code::FindFirstCode() {
   ASSERT(is_inline_cache_stub());
   DisallowHeapAllocation no_allocation;
   int mask = RelocInfo::ModeMask(RelocInfo::CODE_TARGET);
   for (RelocIterator it(this, mask); !it.done(); it.next()) {
     RelocInfo* info = it.rinfo();
     return Code::GetCodeFromTargetAddress(info->target_address());
   }
   return NULL;
 }
@@ skipping 21 matching lines @@
   int mask = RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT);
   for (RelocIterator it(this, mask); !it.done(); it.next()) {
     RelocInfo* info = it.rinfo();
     Object* object = info->target_object();
     if (object->IsName()) return Name::cast(object);
   }
   return NULL;
 }
 
 
+void Code::ReplaceNthCell(int n,
+                          Cell* replace_with) {

[rossberg, 2013/06/25 10:47:38]

Nit: this fits on the previous line

[danno, 2013/06/28 13:56:05]

Done.

+  ASSERT(is_inline_cache_stub());
+  DisallowHeapAllocation no_allocation;
+  int mask = RelocInfo::ModeMask(RelocInfo::CELL);
+  for (RelocIterator it(this, mask); !it.done(); it.next()) {
+    RelocInfo* info = it.rinfo();
+    if (--n == 0) {
+      info->set_target_cell(replace_with);
+      return;
+    }
+  }
+  UNREACHABLE();
+}
+
+
 void Code::ClearInlineCaches() {
   int mask = RelocInfo::ModeMask(RelocInfo::CODE_TARGET) |
              RelocInfo::ModeMask(RelocInfo::CONSTRUCT_CALL) |
              RelocInfo::ModeMask(RelocInfo::CODE_TARGET_WITH_ID) |
              RelocInfo::ModeMask(RelocInfo::CODE_TARGET_CONTEXT);
   for (RelocIterator it(this, mask); !it.done(); it.next()) {
     RelocInfo* info = it.rinfo();
     Code* target(Code::GetCodeFromTargetAddress(info->target_address()));
     if (target->is_inline_cache_stub()) {
       IC::Clear(info->pc());
@@ skipping 863 matching lines @@
                 proto_transitions->length());
 }
 
 
 void Map::AddDependentCompilationInfo(DependentCode::DependencyGroup group,
                                       CompilationInfo* info) {
   Handle<DependentCode> dep(dependent_code());
   Handle<DependentCode> codes =
       DependentCode::Insert(dep, group, info->object_wrapper());
   if (*codes != dependent_code()) set_dependent_code(*codes);
-  info->dependent_maps(group)->Add(Handle<Map>(this), info->zone());
+  info->dependencies(group)->Add(Handle<HeapObject>(this), info->zone());
 }
 
 
 void Map::AddDependentCode(DependentCode::DependencyGroup group,
                            Handle<Code> code) {
   Handle<DependentCode> codes = DependentCode::Insert(
       Handle<DependentCode>(dependent_code()), group, code);
   if (*codes != dependent_code()) set_dependent_code(*codes);
 }
 
 
 DependentCode::GroupStartIndexes::GroupStartIndexes(DependentCode* entries) {
   Recompute(entries);
 }
 
 
 void DependentCode::GroupStartIndexes::Recompute(DependentCode* entries) {
   start_indexes_[0] = 0;
   for (int g = 1; g <= kGroupCount; g++) {
     int count = entries->number_of_entries(static_cast<DependencyGroup>(g - 1));
     start_indexes_[g] = start_indexes_[g - 1] + count;
   }
 }
 
 
+DependentCode* DependentCode::ForObject(Handle<HeapObject> object,
+                                        DependencyGroup group) {
+  AllowDeferredHandleDereference dependencies_are_safe;
+  if (group == DependentCode::kPropertyCellChangedGroup) {
+    return Handle<PropertyCell>::cast(object)->dependent_code();
+  }
+  return Handle<Map>::cast(object)->dependent_code();
+}
+
+
 Handle<DependentCode> DependentCode::Insert(Handle<DependentCode> entries,
                                             DependencyGroup group,
                                             Handle<Object> object) {
   GroupStartIndexes starts(*entries);
   int start = starts.at(group);
   int end = starts.at(group + 1);
   int number_of_entries = starts.number_of_entries();
   if (start < end && entries->object_at(end - 1) == *object) {
     // Do not append the compilation info if it is already in the array.
     // It is sufficient to just check only the last element because
@@ skipping 118 matching lines @@
   int start = starts.at(group);
   int end = starts.at(group + 1);
   int code_entries = starts.number_of_entries();
   if (start == end) return;
   for (int i = start; i < end; i++) {
     if (is_code_at(i)) {
       Code* code = code_at(i);
       code->set_marked_for_deoptimization(true);
     } else {
       CompilationInfo* info = compilation_info_at(i);
-      info->AbortDueToDependentMap();
+      info->AbortDueToDependencyChange();
     }
   }
   // Compact the array by moving all subsequent groups to fill in the new holes.
   for (int src = end, dst = start; src < code_entries; src++, dst++) {
     copy(src, dst);
   }
   // Now the holes are at the end of the array, zap them for heap-verifier.
   int removed = end - start;
   for (int i = code_entries - removed; i < code_entries; i++) {
     clear_at(i);
@@ skipping 4512 matching lines @@
 Type* PropertyCell::type() {
   return static_cast<Type*>(type_raw());
 }
 
 
 void PropertyCell::set_type(Type* type, WriteBarrierMode ignored) {
   set_type_raw(type, ignored);
 }
 
 
+Type* PropertyCell::UnionType(Object* value) {

[rossberg, 2013/06/25 10:47:38]

I'm not sure I fully understand the logic of this function. Intuitively, it
seems more complicated than it should be (I had to draw a state transition
diagram to follow it :) ).

Also, 'UnionType' is a bit of an odd name, since it never computes a proper
union. And it doesn't make it particularly obvious that it has the side effect
of causing deopts. How about something like 'UpdateType'?

[danno, 2013/06/28 13:56:05]

Done.

+  Isolate* isolate = GetIsolate();
+  Handle<Object> value_handle(value, isolate);
+  Handle<Type> old_type(type(), isolate);
+  Handle<Type> new_type(Type::Constant(value_handle, isolate), isolate);
+
+  if (new_type->Is(old_type) && !value->IsTheHole()) {

[rossberg, 2013/06/25 10:47:38]

There is repeated special-casing for the hole. Maybe that can be avoided by
initialising new_type as:

  Handle<Type> new_type(value->IsTheHole() ? Type::Any() :
Type::Constant(value_handle, isolate), isolate);

[danno, 2013/06/28 13:56:05]

Done.

+    return *old_type;
+  }
+
+  dependent_code()->DeoptimizeDependentCodeGroup(
+      isolate, DependentCode::kPropertyCellChangedGroup);
+
+  if (*old_type == Type::None()) {

[rossberg, 2013/06/25 10:47:38]

Please don't rely on pointer equality for types. This should be
"old_type->Is(Type::None())".

[danno, 2013/06/28 13:56:05]

Done.

+    if (new_type->IsConstant() && !value->IsTheHole()) {

[rossberg, 2013/06/25 10:47:38]

Given that new_type is initialised to a Constant above, the first part of the
condition seems redundant. Moreover, if you initialise new_type as I suggested
above, I believe you can return new_type unconditionally.

[danno, 2013/06/28 13:56:05]

Done.

+      return *new_type;
+    }
+  } else if (old_type->IsConstant() && old_type->AsConstant()->IsUndefined()) {

[rossberg, 2013/06/25 10:47:38]

I think you can just as well test "old_type->Is(Type::Undefined())" for this.

Also, IIUC, you allow overriding undefined with the hole here.

[danno, 2013/06/28 13:56:05]

Done.

+    return *new_type;
+  }
+
+  return Type::Any();
+}
+
+
+void PropertyCell::set_value_infer_type(Object* value,
+                                        WriteBarrierMode ignored) {
+  set_value(value, ignored);
+  set_type(UnionType(value));
+}
+
+
+void PropertyCell::AddDependentCompilationInfo(CompilationInfo* info) {
+  Handle<DependentCode> dep(dependent_code());
+  Handle<DependentCode> codes =
+      DependentCode::Insert(dep, DependentCode::kPropertyCellChangedGroup,
+                            info->object_wrapper());
+  if (*codes != dependent_code()) set_dependent_code(*codes);
+  info->dependencies(DependentCode::kPropertyCellChangedGroup)->Add(
+      Handle<HeapObject>(this), info->zone());
+}
+
+
+void PropertyCell::AddDependentCode(Handle<Code> code) {
+  Handle<DependentCode> codes = DependentCode::Insert(
+      Handle<DependentCode>(dependent_code()),
+      DependentCode::kPropertyCellChangedGroup, code);
+  if (*codes != dependent_code()) set_dependent_code(*codes);
+}
+
+
 } }  // namespace v8::internal