[heap] Remove StaticVisitorBase; Introduce Map::GetVisitorId

Bug: chromium:738368
Change-Id: I749517391f9d5dd0827f3d37f975f6c61542d1ff
Reviewed-on: https://chromium-review.googlesource.com/558914
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46391}

src/heap/heap.cc

@@ -2187,29 +2187,28 @@ AllocationResult Heap::AllocatePartialMap(InstanceType instance_type,
   AllocationResult allocation = AllocateRaw(Map::kSize, MAP_SPACE);
   if (!allocation.To(&result)) return allocation;
   // Map::cast cannot be used due to uninitialized map field.
-  reinterpret_cast<Map*>(result)->set_map_after_allocation(
-      reinterpret_cast<Map*>(root(kMetaMapRootIndex)), SKIP_WRITE_BARRIER);
-  reinterpret_cast<Map*>(result)->set_instance_type(instance_type);
-  reinterpret_cast<Map*>(result)->set_instance_size(instance_size);
+  Map* map = reinterpret_cast<Map*>(result);
+  map->set_map_after_allocation(reinterpret_cast<Map*>(root(kMetaMapRootIndex)),
+                                SKIP_WRITE_BARRIER);
+  map->set_instance_type(instance_type);
+  map->set_instance_size(instance_size);
   // Initialize to only containing tagged fields.
-  reinterpret_cast<Map*>(result)->set_visitor_id(
-      StaticVisitorBase::GetVisitorId(instance_type, instance_size, false));
   if (FLAG_unbox_double_fields) {
-    reinterpret_cast<Map*>(result)
-        ->set_layout_descriptor(LayoutDescriptor::FastPointerLayout());
-  }
-  reinterpret_cast<Map*>(result)->clear_unused();
-  reinterpret_cast<Map*>(result)
-      ->set_inobject_properties_or_constructor_function_index(0);
-  reinterpret_cast<Map*>(result)->set_unused_property_fields(0);
-  reinterpret_cast<Map*>(result)->set_bit_field(0);
-  reinterpret_cast<Map*>(result)->set_bit_field2(0);
+    map->set_layout_descriptor(LayoutDescriptor::FastPointerLayout());
+  }
+  // GetVisitorId requires a properly initialized LayoutDescriptor.
+  map->set_visitor_id(Map::GetVisitorId(map));
+  map->clear_unused();
+  map->set_inobject_properties_or_constructor_function_index(0);
+  map->set_unused_property_fields(0);
+  map->set_bit_field(0);
+  map->set_bit_field2(0);
   int bit_field3 = Map::EnumLengthBits::encode(kInvalidEnumCacheSentinel) |
                    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::kZero);
-  return result;
+  map->set_bit_field3(bit_field3);
+  map->set_weak_cell_cache(Smi::kZero);
+  return map;
 }
 
 
@@ -2241,7 +2240,7 @@ AllocationResult Heap::AllocateMap(InstanceType instance_type,
   }
   // Must be called only after |instance_type|, |instance_size| and
   // |layout_descriptor| are set.
-  map->set_visitor_id(Heap::GetStaticVisitorIdForMap(map));
+  map->set_visitor_id(Map::GetVisitorId(map));
   map->set_bit_field(0);
   map->set_bit_field2(1 << Map::kIsExtensible);
   int bit_field3 = Map::EnumLengthBits::encode(kInvalidEnumCacheSentinel) |
@@ -6692,12 +6691,6 @@ bool Heap::GetObjectTypeName(size_t index, const char** object_type,
   return false;
 }
 
-
-// static
-int Heap::GetStaticVisitorIdForMap(Map* map) {
-  return StaticVisitorBase::GetVisitorId(map);
-}
-
 const char* AllocationSpaceName(AllocationSpace space) {
   switch (space) {
     case NEW_SPACE:

src/heap/heap.h

@@ -728,10 +728,6 @@ class Heap {
   // by pointer size.
   static inline void CopyBlock(Address dst, Address src, int byte_size);
 
-  // Determines a static visitor id based on the given {map} that can then be
-  // stored on the map to facilitate fast dispatch for {StaticVisitorBase}.
-  static int GetStaticVisitorIdForMap(Map* map);
-
   // Notifies the heap that is ok to start marking or other activities that
   // should not happen during deserialization.
   void NotifyDeserializationComplete();

src/heap/objects-visiting-inl.h

@@ -17,205 +17,6 @@
 namespace v8 {
 namespace internal {
 
-VisitorId StaticVisitorBase::GetVisitorId(Map* map) {
-  return GetVisitorId(map->instance_type(), map->instance_size(),
-                      FLAG_unbox_double_fields && !map->HasFastPointerLayout());
-}
-
-VisitorId StaticVisitorBase::GetVisitorId(int instance_type, int instance_size,
-                                          bool has_unboxed_fields) {
-  if (instance_type < FIRST_NONSTRING_TYPE) {
-    switch (instance_type & kStringRepresentationMask) {
-      case kSeqStringTag:
-        if ((instance_type & kStringEncodingMask) == kOneByteStringTag) {
-          return kVisitSeqOneByteString;
-        } else {
-          return kVisitSeqTwoByteString;
-        }
-
-      case kConsStringTag:
-        if (IsShortcutCandidate(instance_type)) {
-          return kVisitShortcutCandidate;
-        } else {
-          return kVisitConsString;
-        }
-
-      case kSlicedStringTag:
-        return kVisitSlicedString;
-
-      case kExternalStringTag:
-        return kVisitDataObject;
-
-      case kThinStringTag:
-        return kVisitThinString;
-    }
-    UNREACHABLE();
-  }
-
-  switch (instance_type) {
-    case BYTE_ARRAY_TYPE:
-      return kVisitByteArray;
-
-    case BYTECODE_ARRAY_TYPE:
-      return kVisitBytecodeArray;
-
-    case FREE_SPACE_TYPE:
-      return kVisitFreeSpace;
-
-    case FIXED_ARRAY_TYPE:
-      return kVisitFixedArray;
-
-    case FIXED_DOUBLE_ARRAY_TYPE:
-      return kVisitFixedDoubleArray;
-
-    case ODDBALL_TYPE:
-      return kVisitOddball;
-
-    case MAP_TYPE:
-      return kVisitMap;
-
-    case CODE_TYPE:
-      return kVisitCode;
-
-    case CELL_TYPE:
-      return kVisitCell;
-
-    case PROPERTY_CELL_TYPE:
-      return kVisitPropertyCell;
-
-    case WEAK_CELL_TYPE:
-      return kVisitWeakCell;
-
-    case TRANSITION_ARRAY_TYPE:
-      return kVisitTransitionArray;
-
-    case JS_WEAK_MAP_TYPE:
-    case JS_WEAK_SET_TYPE:
-      return kVisitJSWeakCollection;
-
-    case JS_REGEXP_TYPE:
-      return kVisitJSRegExp;
-
-    case SHARED_FUNCTION_INFO_TYPE:
-      return kVisitSharedFunctionInfo;
-
-    case JS_PROXY_TYPE:
-      return kVisitStruct;
-
-    case SYMBOL_TYPE:
-      return kVisitSymbol;
-
-    case JS_ARRAY_BUFFER_TYPE:
-      return kVisitJSArrayBuffer;
-
-    case SMALL_ORDERED_HASH_MAP_TYPE:
-      return kVisitSmallOrderedHashMap;
-
-    case SMALL_ORDERED_HASH_SET_TYPE:
-      return kVisitSmallOrderedHashSet;
-
-    case JS_OBJECT_TYPE:
-    case JS_ERROR_TYPE:
-    case JS_ARGUMENTS_TYPE:
-    case JS_ASYNC_FROM_SYNC_ITERATOR_TYPE:
-    case JS_CONTEXT_EXTENSION_OBJECT_TYPE:
-    case JS_GENERATOR_OBJECT_TYPE:
-    case JS_ASYNC_GENERATOR_OBJECT_TYPE:
-    case JS_MODULE_NAMESPACE_TYPE:
-    case JS_VALUE_TYPE:
-    case JS_DATE_TYPE:
-    case JS_ARRAY_TYPE:
-    case JS_GLOBAL_PROXY_TYPE:
-    case JS_GLOBAL_OBJECT_TYPE:
-    case JS_MESSAGE_OBJECT_TYPE:
-    case JS_TYPED_ARRAY_TYPE:
-    case JS_DATA_VIEW_TYPE:
-    case JS_SET_TYPE:
-    case JS_MAP_TYPE:
-    case JS_SET_ITERATOR_TYPE:
-    case JS_MAP_ITERATOR_TYPE:
-    case JS_STRING_ITERATOR_TYPE:
-
-    case JS_TYPED_ARRAY_KEY_ITERATOR_TYPE:
-    case JS_FAST_ARRAY_KEY_ITERATOR_TYPE:
-    case JS_GENERIC_ARRAY_KEY_ITERATOR_TYPE:
-    case JS_UINT8_ARRAY_KEY_VALUE_ITERATOR_TYPE:
-    case JS_INT8_ARRAY_KEY_VALUE_ITERATOR_TYPE:
-    case JS_UINT16_ARRAY_KEY_VALUE_ITERATOR_TYPE:
-    case JS_INT16_ARRAY_KEY_VALUE_ITERATOR_TYPE:
-    case JS_UINT32_ARRAY_KEY_VALUE_ITERATOR_TYPE:
-    case JS_INT32_ARRAY_KEY_VALUE_ITERATOR_TYPE:
-    case JS_FLOAT32_ARRAY_KEY_VALUE_ITERATOR_TYPE:
-    case JS_FLOAT64_ARRAY_KEY_VALUE_ITERATOR_TYPE:
-    case JS_UINT8_CLAMPED_ARRAY_KEY_VALUE_ITERATOR_TYPE:
-    case JS_FAST_SMI_ARRAY_KEY_VALUE_ITERATOR_TYPE:
-    case JS_FAST_HOLEY_SMI_ARRAY_KEY_VALUE_ITERATOR_TYPE:
-    case JS_FAST_ARRAY_KEY_VALUE_ITERATOR_TYPE:
-    case JS_FAST_HOLEY_ARRAY_KEY_VALUE_ITERATOR_TYPE:
-    case JS_FAST_DOUBLE_ARRAY_KEY_VALUE_ITERATOR_TYPE:
-    case JS_FAST_HOLEY_DOUBLE_ARRAY_KEY_VALUE_ITERATOR_TYPE:
-    case JS_GENERIC_ARRAY_KEY_VALUE_ITERATOR_TYPE:
-    case JS_UINT8_ARRAY_VALUE_ITERATOR_TYPE:
-    case JS_INT8_ARRAY_VALUE_ITERATOR_TYPE:
-    case JS_UINT16_ARRAY_VALUE_ITERATOR_TYPE:
-    case JS_INT16_ARRAY_VALUE_ITERATOR_TYPE:
-    case JS_UINT32_ARRAY_VALUE_ITERATOR_TYPE:
-    case JS_INT32_ARRAY_VALUE_ITERATOR_TYPE:
-    case JS_FLOAT32_ARRAY_VALUE_ITERATOR_TYPE:
-    case JS_FLOAT64_ARRAY_VALUE_ITERATOR_TYPE:
-    case JS_UINT8_CLAMPED_ARRAY_VALUE_ITERATOR_TYPE:
-    case JS_FAST_SMI_ARRAY_VALUE_ITERATOR_TYPE:
-    case JS_FAST_HOLEY_SMI_ARRAY_VALUE_ITERATOR_TYPE:
-    case JS_FAST_ARRAY_VALUE_ITERATOR_TYPE:
-    case JS_FAST_HOLEY_ARRAY_VALUE_ITERATOR_TYPE:
-    case JS_FAST_DOUBLE_ARRAY_VALUE_ITERATOR_TYPE:
-    case JS_FAST_HOLEY_DOUBLE_ARRAY_VALUE_ITERATOR_TYPE:
-    case JS_GENERIC_ARRAY_VALUE_ITERATOR_TYPE:
-
-    case JS_PROMISE_CAPABILITY_TYPE:
-    case JS_PROMISE_TYPE:
-    case JS_BOUND_FUNCTION_TYPE:
-      return has_unboxed_fields ? kVisitJSObject : kVisitJSObjectFast;
-    case JS_API_OBJECT_TYPE:
-    case JS_SPECIAL_API_OBJECT_TYPE:
-      return kVisitJSApiObject;
-
-    case JS_FUNCTION_TYPE:
-      return kVisitJSFunction;
-
-    case FILLER_TYPE:
-    case FOREIGN_TYPE:
-    case HEAP_NUMBER_TYPE:
-    case MUTABLE_HEAP_NUMBER_TYPE:
-      return kVisitDataObject;
-
-    case FIXED_UINT8_ARRAY_TYPE:
-    case FIXED_INT8_ARRAY_TYPE:
-    case FIXED_UINT16_ARRAY_TYPE:
-    case FIXED_INT16_ARRAY_TYPE:
-    case FIXED_UINT32_ARRAY_TYPE:
-    case FIXED_INT32_ARRAY_TYPE:
-    case FIXED_FLOAT32_ARRAY_TYPE:
-    case FIXED_UINT8_CLAMPED_ARRAY_TYPE:
-      return kVisitFixedTypedArrayBase;
-
-    case FIXED_FLOAT64_ARRAY_TYPE:
-      return kVisitFixedFloat64Array;
-
-#define MAKE_STRUCT_CASE(NAME, Name, name) case NAME##_TYPE:
-      STRUCT_LIST(MAKE_STRUCT_CASE)
-#undef MAKE_STRUCT_CASE
-      if (instance_type == ALLOCATION_SITE_TYPE) {
-        return kVisitAllocationSite;
-      }
-
-      return kVisitStruct;
-
-    default:
-      UNREACHABLE();
-  }
-}
-
 template <typename ResultType, typename ConcreteVisitor>
 ResultType HeapVisitor<ResultType, ConcreteVisitor>::Visit(HeapObject* object) {
   return Visit(object->map(), object);

src/heap/objects-visiting.h

@@ -14,74 +14,6 @@
 namespace v8 {
 namespace internal {
 
-#define VISITOR_ID_LIST(V) \
-  V(AllocationSite)        \
-  V(ByteArray)             \
-  V(BytecodeArray)         \
-  V(Cell)                  \
-  V(Code)                  \
-  V(ConsString)            \
-  V(DataObject)            \
-  V(FixedArray)            \
-  V(FixedDoubleArray)      \
-  V(FixedFloat64Array)     \
-  V(FixedTypedArrayBase)   \
-  V(FreeSpace)             \
-  V(JSApiObject)           \
-  V(JSArrayBuffer)         \
-  V(JSFunction)            \
-  V(JSObject)              \
-  V(JSObjectFast)          \
-  V(JSRegExp)              \
-  V(JSWeakCollection)      \
-  V(Map)                   \
-  V(NativeContext)         \
-  V(Oddball)               \
-  V(PropertyCell)          \
-  V(SeqOneByteString)      \
-  V(SeqTwoByteString)      \
-  V(SharedFunctionInfo)    \
-  V(ShortcutCandidate)     \
-  V(SlicedString)          \
-  V(SmallOrderedHashMap)   \
-  V(SmallOrderedHashSet)   \
-  V(Struct)                \
-  V(Symbol)                \
-  V(ThinString)            \
-  V(TransitionArray)       \
-  V(WeakCell)
-
-// For data objects, JS objects and structs along with generic visitor which
-// can visit object of any size we provide visitors specialized by
-// object size in words.
-// Ids of specialized visitors are declared in a linear order (without
-// holes) starting from the id of visitor specialized for 2 words objects
-// (base visitor id) and ending with the id of generic visitor.
-// Method GetVisitorIdForSize depends on this ordering to calculate visitor
-// id of specialized visitor from given instance size, base visitor id and
-// generic visitor's id.
-enum VisitorId {
-#define VISITOR_ID_ENUM_DECL(id) kVisit##id,
-  VISITOR_ID_LIST(VISITOR_ID_ENUM_DECL)
-#undef VISITOR_ID_ENUM_DECL
-      kVisitorIdCount
-};
-
-// Base class for all static visitors.
-class StaticVisitorBase : public AllStatic {
- public:
-  // Visitor ID should fit in one byte.
-  STATIC_ASSERT(kVisitorIdCount <= 256);
-
-  // Determine which specialized visitor should be used for given instance type
-  // and instance type.
-  static inline VisitorId GetVisitorId(int instance_type, int instance_size,
-                                       bool has_unboxed_fields);
-
-  // Determine which specialized visitor should be used for given map.
-  static inline VisitorId GetVisitorId(Map* map);
-};
-
 #define TYPED_VISITOR_ID_LIST(V) \
   V(AllocationSite)              \
   V(ByteArray)                   \
@@ -112,10 +44,9 @@ class StaticVisitorBase : public AllStatic {
   V(TransitionArray)             \
   V(WeakCell)
 
-// The base class for visitors that need to dispatch on object type. It is
-// similar to StaticVisitor except it uses virtual dispatch instead of static
-// dispatch table. The default behavior of all visit functions is to iterate
-// body of the given object using the BodyDescriptor of the object.
+// The base class for visitors that need to dispatch on object type. The default
+// behavior of all visit functions is to iterate body of the given object using
+// the BodyDescriptor of the object.
 //
 // The visit functions return the size of the object cast to ResultType.
 //
@@ -124,8 +55,6 @@ class StaticVisitorBase : public AllStatic {
 //   class SomeVisitor : public HeapVisitor<ResultType, SomeVisitor> {
 //     ...
 //   }
-//
-// TODO(ulan): replace static visitors with the HeapVisitor.
 template <typename ResultType, typename ConcreteVisitor>
 class HeapVisitor : public ObjectVisitor {
  public:

src/heap/scavenger-inl.h

@@ -6,11 +6,15 @@
 #define V8_HEAP_SCAVENGER_INL_H_
 
 #include "src/heap/scavenger.h"
+#include "src/objects/map.h"
 
 namespace v8 {
 namespace internal {
 
-bool Scavenger::ContainsOnlyData(VisitorId visitor_id) {
+namespace {
+
+// White list for objects that for sure only contain data.
+bool ContainsOnlyData(VisitorId visitor_id) {
   switch (visitor_id) {
     case kVisitSeqOneByteString:
       return true;
@@ -28,6 +32,8 @@ bool Scavenger::ContainsOnlyData(VisitorId visitor_id) {
   return false;
 }
 
+}  // namespace
+
 // Helper function used by CopyObject to copy a source object to an
 // allocated target object and update the forwarding pointer in the source
 // object. Returns the target object.

src/heap/scavenger.h

@@ -32,9 +32,6 @@ class Scavenger {
   inline Heap* heap() { return heap_; }
 
  private:
-  // White list for objects that for sure only contain data.
-  V8_INLINE static bool ContainsOnlyData(VisitorId visitor_id);
-
   V8_INLINE HeapObject* MigrateObject(HeapObject* source, HeapObject* target,
                                       int size);
 

src/objects-debug.cc

@@ -425,7 +425,7 @@ void Map::DictionaryMapVerify() {
   CHECK(is_dictionary_map());
   CHECK(instance_descriptors()->IsEmpty());
   CHECK_EQ(0, unused_property_fields());
-  CHECK_EQ(Heap::GetStaticVisitorIdForMap(this), visitor_id());
+  CHECK_EQ(Map::GetVisitorId(this), visitor_id());
 }
 
 

src/objects-inl.h

@@ -4273,11 +4273,11 @@ void Map::UpdateDescriptors(DescriptorArray* descriptors,
     // TODO(ishell): remove these checks from VERIFY_HEAP mode.
     if (FLAG_verify_heap) {
       CHECK(layout_descriptor()->IsConsistentWithMap(this));
-      CHECK(visitor_id() == Heap::GetStaticVisitorIdForMap(this));
+      CHECK(visitor_id() == Map::GetVisitorId(this));
     }
 #else
     SLOW_DCHECK(layout_descriptor()->IsConsistentWithMap(this));
-    DCHECK(visitor_id() == Heap::GetStaticVisitorIdForMap(this));
+    DCHECK(visitor_id() == Map::GetVisitorId(this));
 #endif
   }
 }
@@ -4299,7 +4299,7 @@ void Map::InitializeDescriptors(DescriptorArray* descriptors,
 #else
     SLOW_DCHECK(layout_descriptor()->IsConsistentWithMap(this));
 #endif
-    set_visitor_id(Heap::GetStaticVisitorIdForMap(this));
+    set_visitor_id(Map::GetVisitorId(this));
   }
 }
 

src/objects.cc

@@ -2855,6 +2855,204 @@ void Map::PrintReconfiguration(FILE* file, int modify_index, PropertyKind kind,
   os << "]\n";
 }
 
+VisitorId Map::GetVisitorId(Map* map) {
+  STATIC_ASSERT(kVisitorIdCount <= 256);
+
+  const int instance_type = map->instance_type();
+  const bool has_unboxed_fields =
+      FLAG_unbox_double_fields && !map->HasFastPointerLayout();
+  if (instance_type < FIRST_NONSTRING_TYPE) {
+    switch (instance_type & kStringRepresentationMask) {
+      case kSeqStringTag:
+        if ((instance_type & kStringEncodingMask) == kOneByteStringTag) {
+          return kVisitSeqOneByteString;
+        } else {
+          return kVisitSeqTwoByteString;
+        }
+
+      case kConsStringTag:
+        if (IsShortcutCandidate(instance_type)) {
+          return kVisitShortcutCandidate;
+        } else {
+          return kVisitConsString;
+        }
+
+      case kSlicedStringTag:
+        return kVisitSlicedString;
+
+      case kExternalStringTag:
+        return kVisitDataObject;
+
+      case kThinStringTag:
+        return kVisitThinString;
+    }
+    UNREACHABLE();
+  }
+
+  switch (instance_type) {
+    case BYTE_ARRAY_TYPE:
+      return kVisitByteArray;
+
+    case BYTECODE_ARRAY_TYPE:
+      return kVisitBytecodeArray;
+
+    case FREE_SPACE_TYPE:
+      return kVisitFreeSpace;
+
+    case FIXED_ARRAY_TYPE:
+      return kVisitFixedArray;
+
+    case FIXED_DOUBLE_ARRAY_TYPE:
+      return kVisitFixedDoubleArray;
+
+    case ODDBALL_TYPE:
+      return kVisitOddball;
+
+    case MAP_TYPE:
+      return kVisitMap;
+
+    case CODE_TYPE:
+      return kVisitCode;
+
+    case CELL_TYPE:
+      return kVisitCell;
+
+    case PROPERTY_CELL_TYPE:
+      return kVisitPropertyCell;
+
+    case WEAK_CELL_TYPE:
+      return kVisitWeakCell;
+
+    case TRANSITION_ARRAY_TYPE:
+      return kVisitTransitionArray;
+
+    case JS_WEAK_MAP_TYPE:
+    case JS_WEAK_SET_TYPE:
+      return kVisitJSWeakCollection;
+
+    case JS_REGEXP_TYPE:
+      return kVisitJSRegExp;
+
+    case SHARED_FUNCTION_INFO_TYPE:
+      return kVisitSharedFunctionInfo;
+
+    case JS_PROXY_TYPE:
+      return kVisitStruct;
+
+    case SYMBOL_TYPE:
+      return kVisitSymbol;
+
+    case JS_ARRAY_BUFFER_TYPE:
+      return kVisitJSArrayBuffer;
+
+    case SMALL_ORDERED_HASH_MAP_TYPE:
+      return kVisitSmallOrderedHashMap;
+
+    case SMALL_ORDERED_HASH_SET_TYPE:
+      return kVisitSmallOrderedHashSet;
+
+    case JS_OBJECT_TYPE:
+    case JS_ERROR_TYPE:
+    case JS_ARGUMENTS_TYPE:
+    case JS_ASYNC_FROM_SYNC_ITERATOR_TYPE:
+    case JS_CONTEXT_EXTENSION_OBJECT_TYPE:
+    case JS_GENERATOR_OBJECT_TYPE:
+    case JS_ASYNC_GENERATOR_OBJECT_TYPE:
+    case JS_MODULE_NAMESPACE_TYPE:
+    case JS_VALUE_TYPE:
+    case JS_DATE_TYPE:
+    case JS_ARRAY_TYPE:
+    case JS_GLOBAL_PROXY_TYPE:
+    case JS_GLOBAL_OBJECT_TYPE:
+    case JS_MESSAGE_OBJECT_TYPE:
+    case JS_TYPED_ARRAY_TYPE:
+    case JS_DATA_VIEW_TYPE:
+    case JS_SET_TYPE:
+    case JS_MAP_TYPE:
+    case JS_SET_ITERATOR_TYPE:
+    case JS_MAP_ITERATOR_TYPE:
+    case JS_STRING_ITERATOR_TYPE:
+
+    case JS_TYPED_ARRAY_KEY_ITERATOR_TYPE:
+    case JS_FAST_ARRAY_KEY_ITERATOR_TYPE:
+    case JS_GENERIC_ARRAY_KEY_ITERATOR_TYPE:
+    case JS_UINT8_ARRAY_KEY_VALUE_ITERATOR_TYPE:
+    case JS_INT8_ARRAY_KEY_VALUE_ITERATOR_TYPE:
+    case JS_UINT16_ARRAY_KEY_VALUE_ITERATOR_TYPE:
+    case JS_INT16_ARRAY_KEY_VALUE_ITERATOR_TYPE:
+    case JS_UINT32_ARRAY_KEY_VALUE_ITERATOR_TYPE:
+    case JS_INT32_ARRAY_KEY_VALUE_ITERATOR_TYPE:
+    case JS_FLOAT32_ARRAY_KEY_VALUE_ITERATOR_TYPE:
+    case JS_FLOAT64_ARRAY_KEY_VALUE_ITERATOR_TYPE:
+    case JS_UINT8_CLAMPED_ARRAY_KEY_VALUE_ITERATOR_TYPE:
+    case JS_FAST_SMI_ARRAY_KEY_VALUE_ITERATOR_TYPE:
+    case JS_FAST_HOLEY_SMI_ARRAY_KEY_VALUE_ITERATOR_TYPE:
+    case JS_FAST_ARRAY_KEY_VALUE_ITERATOR_TYPE:
+    case JS_FAST_HOLEY_ARRAY_KEY_VALUE_ITERATOR_TYPE:
+    case JS_FAST_DOUBLE_ARRAY_KEY_VALUE_ITERATOR_TYPE:
+    case JS_FAST_HOLEY_DOUBLE_ARRAY_KEY_VALUE_ITERATOR_TYPE:
+    case JS_GENERIC_ARRAY_KEY_VALUE_ITERATOR_TYPE:
+    case JS_UINT8_ARRAY_VALUE_ITERATOR_TYPE:
+    case JS_INT8_ARRAY_VALUE_ITERATOR_TYPE:
+    case JS_UINT16_ARRAY_VALUE_ITERATOR_TYPE:
+    case JS_INT16_ARRAY_VALUE_ITERATOR_TYPE:
+    case JS_UINT32_ARRAY_VALUE_ITERATOR_TYPE:
+    case JS_INT32_ARRAY_VALUE_ITERATOR_TYPE:
+    case JS_FLOAT32_ARRAY_VALUE_ITERATOR_TYPE:
+    case JS_FLOAT64_ARRAY_VALUE_ITERATOR_TYPE:
+    case JS_UINT8_CLAMPED_ARRAY_VALUE_ITERATOR_TYPE:
+    case JS_FAST_SMI_ARRAY_VALUE_ITERATOR_TYPE:
+    case JS_FAST_HOLEY_SMI_ARRAY_VALUE_ITERATOR_TYPE:
+    case JS_FAST_ARRAY_VALUE_ITERATOR_TYPE:
+    case JS_FAST_HOLEY_ARRAY_VALUE_ITERATOR_TYPE:
+    case JS_FAST_DOUBLE_ARRAY_VALUE_ITERATOR_TYPE:
+    case JS_FAST_HOLEY_DOUBLE_ARRAY_VALUE_ITERATOR_TYPE:
+    case JS_GENERIC_ARRAY_VALUE_ITERATOR_TYPE:
+
+    case JS_PROMISE_CAPABILITY_TYPE:
+    case JS_PROMISE_TYPE:
+    case JS_BOUND_FUNCTION_TYPE:
+      return has_unboxed_fields ? kVisitJSObject : kVisitJSObjectFast;
+    case JS_API_OBJECT_TYPE:
+    case JS_SPECIAL_API_OBJECT_TYPE:
+      return kVisitJSApiObject;
+
+    case JS_FUNCTION_TYPE:
+      return kVisitJSFunction;
+
+    case FILLER_TYPE:
+    case FOREIGN_TYPE:
+    case HEAP_NUMBER_TYPE:
+    case MUTABLE_HEAP_NUMBER_TYPE:
+      return kVisitDataObject;
+
+    case FIXED_UINT8_ARRAY_TYPE:
+    case FIXED_INT8_ARRAY_TYPE:
+    case FIXED_UINT16_ARRAY_TYPE:
+    case FIXED_INT16_ARRAY_TYPE:
+    case FIXED_UINT32_ARRAY_TYPE:
+    case FIXED_INT32_ARRAY_TYPE:
+    case FIXED_FLOAT32_ARRAY_TYPE:
+    case FIXED_UINT8_CLAMPED_ARRAY_TYPE:
+      return kVisitFixedTypedArrayBase;
+
+    case FIXED_FLOAT64_ARRAY_TYPE:
+      return kVisitFixedFloat64Array;
+
+#define MAKE_STRUCT_CASE(NAME, Name, name) case NAME##_TYPE:
+      STRUCT_LIST(MAKE_STRUCT_CASE)
+#undef MAKE_STRUCT_CASE
+      if (instance_type == ALLOCATION_SITE_TYPE) {
+        return kVisitAllocationSite;
+      }
+
+      return kVisitStruct;
+
+    default:
+      UNREACHABLE();
+  }
+}
+
 void Map::PrintGeneralization(
     FILE* file, const char* reason, int modify_index, int split,
     int descriptors, bool descriptor_to_field,
@@ -8819,7 +9017,7 @@ void Map::InstallDescriptors(Handle<Map> parent, Handle<Map> child,
 #else
     SLOW_DCHECK(child->layout_descriptor()->IsConsistentWithMap(*child));
 #endif
-    child->set_visitor_id(Heap::GetStaticVisitorIdForMap(*child));
+    child->set_visitor_id(Map::GetVisitorId(*child));
   }
 
   Handle<Name> name = handle(descriptors->GetKey(new_descriptor));
@@ -8970,7 +9168,7 @@ Handle<Map> Map::Create(Isolate* isolate, int inobject_properties) {
   copy->SetInObjectProperties(inobject_properties);
   copy->set_unused_property_fields(inobject_properties);
   copy->set_instance_size(new_instance_size);
-  copy->set_visitor_id(Heap::GetStaticVisitorIdForMap(*copy));
+  copy->set_visitor_id(Map::GetVisitorId(*copy));
   return copy;
 }
 
@@ -11909,7 +12107,7 @@ static void GetMinInobjectSlack(Map* map, void* data) {
 
 static void ShrinkInstanceSize(Map* map, void* data) {
 #ifdef DEBUG
-  int old_visitor_id = Heap::GetStaticVisitorIdForMap(map);
+  int old_visitor_id = Map::GetVisitorId(map);
 #endif
   int slack = *reinterpret_cast<int*>(data);
   DCHECK_GE(slack, 0);
@@ -11917,7 +12115,7 @@ static void ShrinkInstanceSize(Map* map, void* data) {
   map->set_unused_property_fields(map->unused_property_fields() - slack);
   map->set_instance_size(map->instance_size() - slack * kPointerSize);
   map->set_construction_counter(Map::kNoSlackTracking);
-  DCHECK_EQ(old_visitor_id, Heap::GetStaticVisitorIdForMap(map));
+  DCHECK_EQ(old_visitor_id, Map::GetVisitorId(map));
 }
 
 static void StopSlackTracking(Map* map, void* data) {

src/objects/map.h

@@ -15,6 +15,59 @@
 namespace v8 {
 namespace internal {
 
+#define VISITOR_ID_LIST(V) \
+  V(AllocationSite)        \
+  V(ByteArray)             \
+  V(BytecodeArray)         \
+  V(Cell)                  \
+  V(Code)                  \
+  V(ConsString)            \
+  V(DataObject)            \
+  V(FixedArray)            \
+  V(FixedDoubleArray)      \
+  V(FixedFloat64Array)     \
+  V(FixedTypedArrayBase)   \
+  V(FreeSpace)             \
+  V(JSApiObject)           \
+  V(JSArrayBuffer)         \
+  V(JSFunction)            \
+  V(JSObject)              \
+  V(JSObjectFast)          \
+  V(JSRegExp)              \
+  V(JSWeakCollection)      \
+  V(Map)                   \
+  V(NativeContext)         \
+  V(Oddball)               \
+  V(PropertyCell)          \
+  V(SeqOneByteString)      \
+  V(SeqTwoByteString)      \
+  V(SharedFunctionInfo)    \
+  V(ShortcutCandidate)     \
+  V(SlicedString)          \
+  V(SmallOrderedHashMap)   \
+  V(SmallOrderedHashSet)   \
+  V(Struct)                \
+  V(Symbol)                \
+  V(ThinString)            \
+  V(TransitionArray)       \
+  V(WeakCell)
+
+// For data objects, JS objects and structs along with generic visitor which
+// can visit object of any size we provide visitors specialized by
+// object size in words.
+// Ids of specialized visitors are declared in a linear order (without
+// holes) starting from the id of visitor specialized for 2 words objects
+// (base visitor id) and ending with the id of generic visitor.
+// Method GetVisitorIdForSize depends on this ordering to calculate visitor
+// id of specialized visitor from given instance size, base visitor id and
+// generic visitor's id.
+enum VisitorId {
+#define VISITOR_ID_ENUM_DECL(id) kVisit##id,
+  VISITOR_ID_LIST(VISITOR_ID_ENUM_DECL)
+#undef VISITOR_ID_ENUM_DECL
+      kVisitorIdCount
+};
+
 typedef std::vector<Handle<Map>> MapHandles;
 
 // All heap objects have a Map that describes their structure.
@@ -694,6 +747,8 @@ class Map : public HeapObject {
   // the descriptor array.
   inline void NotifyLeafMapLayoutChange();
 
+  static VisitorId GetVisitorId(Map* map);
+
  private:
   // Returns the map that this (root) map transitions to if its elements_kind
   // is changed to |elements_kind|, or |nullptr| if no such map is cached yet.