[heap] Scavenger: Cache compacting property

Bug: chromium:738865
Change-Id: I02cb7ea48a1dfaec25bf702b09242d537fe612f4
Reviewed-on: https://chromium-review.googlesource.com/589271
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46939}

src/heap/heap.cc

@@ -1920,14 +1920,13 @@ void Heap::Scavenge() {
   const int kMainThreadId = 0;
   Scavenger* scavengers[kMaxScavengerTasks];
   const bool is_logging = IsLogging(isolate());
-  const bool is_incremental_marking = incremental_marking()->IsMarking();
   const int num_scavenge_tasks = NumberOfScavengeTasks();
   Scavenger::Barrier barrier;
   CopiedList copied_list(num_scavenge_tasks);
   PromotionList promotion_list(num_scavenge_tasks);
   for (int i = 0; i < num_scavenge_tasks; i++) {
-    scavengers[i] = new Scavenger(this, is_logging, is_incremental_marking,
-                                  &copied_list, &promotion_list, i);
+    scavengers[i] =
+        new Scavenger(this, is_logging, &copied_list, &promotion_list, i);
     job.AddTask(new ScavengingTask(this, scavengers[i], &barrier));
   }
 

src/heap/scavenger.cc

@@ -58,6 +58,19 @@ class IterateAndScavengePromotedObjectsVisitor final : public ObjectVisitor {
   const bool record_slots_;
 };
 
+Scavenger::Scavenger(Heap* heap, bool is_logging, CopiedList* copied_list,
+                     PromotionList* promotion_list, int task_id)
+    : heap_(heap),
+      promotion_list_(promotion_list, task_id),
+      copied_list_(copied_list, task_id),
+      local_pretenuring_feedback_(kInitialLocalPretenuringFeedbackCapacity),
+      copied_size_(0),
+      promoted_size_(0),
+      allocator_(heap),
+      is_logging_(is_logging),
+      is_incremental_marking_(heap->incremental_marking()->IsMarking()),
+      is_compacting_(heap->incremental_marking()->IsCompacting()) {}
+
 void Scavenger::IterateAndScavengePromotedObject(HeapObject* target, int size) {
   // We are not collecting slots on new space objects during mutation
   // thus we have to scan for pointers to evacuation candidates when we
@@ -65,9 +78,9 @@ void Scavenger::IterateAndScavengePromotedObject(HeapObject* target, int size) {
   // objects. Grey object's slots would be rescanned.
   // White object might not survive until the end of collection
   // it would be a violation of the invariant to record it's slots.
-  const bool record_slots = heap()->incremental_marking()->IsCompacting() &&
-                            ObjectMarking::IsBlack<AccessMode::ATOMIC>(
-                                target, MarkingState::Internal(target));
+  const bool record_slots =
+      is_compacting_ && ObjectMarking::IsBlack<AccessMode::ATOMIC>(
+                            target, MarkingState::Internal(target));
   IterateAndScavengePromotedObjectsVisitor visitor(heap(), this, record_slots);
   if (target->IsJSFunction()) {
     // JSFunctions reachable through kNextFunctionLinkOffset are weak. Slots for

src/heap/scavenger.h

@@ -63,17 +63,8 @@ class Scavenger {
     bool done_;
   };
 
-  Scavenger(Heap* heap, bool is_logging, bool is_incremental_marking,
-            CopiedList* copied_list, PromotionList* promotion_list, int task_id)
-      : heap_(heap),
-        promotion_list_(promotion_list, task_id),
-        copied_list_(copied_list, task_id),
-        local_pretenuring_feedback_(kInitialLocalPretenuringFeedbackCapacity),
-        copied_size_(0),
-        promoted_size_(0),
-        allocator_(heap),
-        is_logging_(is_logging),
-        is_incremental_marking_(is_incremental_marking) {}
+  Scavenger(Heap* heap, bool is_logging, CopiedList* copied_list,
+            PromotionList* promotion_list, int task_id);
 
   // Scavenges an object |object| referenced from slot |p|. |object| is required
   // to be in from space.
@@ -142,8 +133,9 @@ class Scavenger {
   size_t copied_size_;
   size_t promoted_size_;
   LocalAllocator allocator_;
-  bool is_logging_;
-  bool is_incremental_marking_;
+  const bool is_logging_;
+  const bool is_incremental_marking_;
+  const bool is_compacting_;
 
   friend class IterateAndScavengePromotedObjectsVisitor;
 };