[object-stats] Distinguish FeedbackVector entries

Record seperate virtual instance types for entries in FeedbackVectors:
- FEEDBACK_VECTOR_ENTRY_TYPE

 Bug: v8:7266

Change-Id: Ibea0615ecd23099e0107505e5d33cf194aade7c0
Reviewed-on: https://chromium-review.googlesource.com/866878
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50678}

src/heap/object-stats.cc

@@ -282,6 +282,7 @@ class ObjectStatsCollectorImpl {
                                 ObjectStats::VirtualInstanceType type,
                                 size_t size);
   void RecordVirtualAllocationSiteDetails(AllocationSite* site);
+  void RecordVirtualFeedbackVectorDetails(FeedbackVector* site);
 
   Heap* heap_;
   ObjectStats* stats_;
@@ -303,11 +304,22 @@ ObjectStatsCollectorImpl::ObjectStatsCollectorImpl(Heap* heap,
 void ObjectStatsCollectorImpl::CollectVirtualStatistics(HeapObject* obj) {
   if (obj->IsAllocationSite()) {
     RecordVirtualAllocationSiteDetails(AllocationSite::cast(obj));
+  } else if (obj->IsFeedbackVector()) {
+    RecordVirtualFeedbackVectorDetails(FeedbackVector::cast(obj));
   }
 }
 
 void ObjectStatsCollectorImpl::RecordVirtualObjectStats(
     HeapObject* obj, ObjectStats::VirtualInstanceType type, size_t size) {
+#if DEBUG
+  if (virtual_objects_.find(obj) != virtual_objects_.end()) {
+    std::stringstream description;
+    obj->Print(description);
+    V8_Fatal(__FILE__, __LINE__,
+             "Object with virtual instance type has been recorded before:\n%s",
+             description.str().c_str());
+  }
+#endif
   virtual_objects_.insert(obj);
   stats_->RecordVirtualObjectStats(type, size);
 }
@@ -348,6 +360,20 @@ void ObjectStatsCollectorImpl::RecordVirtualAllocationSiteDetails(
   }
 }
 
+void ObjectStatsCollectorImpl::RecordVirtualFeedbackVectorDetails(
+    FeedbackVector* vector) {
+  // Except for allocation
+  for (int i = 0; i < vector->length(); i++) {
+    Object* raw_object = vector->get(i);
+    if (!raw_object->IsHeapObject()) continue;
+    HeapObject* object = HeapObject::cast(raw_object);
+    if (object->IsCell() || object->IsFixedArray()) {
+      RecordVirtualObjectStats(object, ObjectStats::FEEDBACK_VECTOR_ENTRY_TYPE,
+                               object->Size());
+    }
+  }
+}
+
 void ObjectStatsCollectorImpl::CollectStatistics(HeapObject* obj) {
   Map* map = obj->map();
 
@@ -438,8 +464,9 @@ void ObjectStatsCollectorImpl::CollectGlobalStatistics() {
 void ObjectStatsCollectorImpl::RecordObjectStats(HeapObject* obj,
                                                  InstanceType type,
                                                  size_t size) {
-  if (virtual_objects_.find(obj) == virtual_objects_.end())
+  if (virtual_objects_.find(obj) == virtual_objects_.end()) {
     stats_->RecordObjectStats(type, size);
+  }
 }
 
 static bool CanRecordFixedArray(Heap* heap, FixedArrayBase* array) {

src/heap/object-stats.h

@@ -23,6 +23,7 @@
   V(BOILERPLATE_ELEMENTS_TYPE)        \
   V(BOILERPLATE_NAME_DICTIONARY_TYPE) \
   V(BOILERPLATE_PROPERTY_ARRAY_TYPE)  \
+  V(FEEDBACK_VECTOR_ENTRY_TYPE)       \
   V(JS_ARRAY_BOILERPLATE_TYPE)        \
   V(JS_OBJECT_BOILERPLATE_TYPE)
 

tools/heap-stats/categories.js

@@ -119,7 +119,7 @@ const CATEGORIES = new Map([
       'PROTOTYPE_INFO_TYPE',
       'STACK_FRAME_INFO_TYPE',
       'TRANSITION_ARRAY_TYPE',
-      'WEAK_CELL_TYPE',
+      'WEAK_CELL_TYPE'
     ])
   ],
   [
@@ -141,6 +141,7 @@ const CATEGORIES = new Map([
       '*FIXED_ARRAY_SHARED_FUNCTION_INFOS_SUB_TYPE',
       'BYTECODE_ARRAY_TYPE',
       'CODE_DATA_CONTAINER_TYPE',
+      'FEEDBACK_VECTOR_ENTRY_TYPE',
       'FEEDBACK_VECTOR_TYPE',
       'LOAD_HANDLER_TYPE',
       'SCRIPT_TYPE',