Immediatelly promote marked objects

src/heap/heap-inl.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HEAP_HEAP_INL_H_
 #define V8_HEAP_HEAP_INL_H_
 
 #include <cmath>
 
 #include "src/base/platform/platform.h"
@@ skipping 375 matching lines @@
 
 bool Heap::InOldSpaceSlow(Address address) {
   return old_space_->ContainsSlow(address);
 }
 
 bool Heap::OldGenerationAllocationLimitReached() {
   if (!incremental_marking()->IsStopped()) return false;
   return OldGenerationSpaceAvailable() < 0;
 }
 
-
+template <MarksHandling marks_handling>
 bool Heap::ShouldBePromoted(Address old_address, int object_size) {
   Page* page = Page::FromAddress(old_address);
   Address age_mark = new_space_.age_mark();
+
+  if (marks_handling == TRANSFER_MARKS) {

[Michael Lippautz, 2016/05/24 11:54:51]

TRANSFER_MARKS is a confusing name for this one as we don't actually transfer
the marks but rather consider them when deciding whether to promote or not.

Maybe have a separate enum and call this one PROMOTE_MARKED?

+    MarkBit mark_bit = Marking::MarkBitFrom(old_address);
+    if (!Marking::IsWhite(mark_bit)) {
+      return true;
+    }
+  }
+
   return page->IsFlagSet(MemoryChunk::NEW_SPACE_BELOW_AGE_MARK) &&
          (!page->ContainsLimit(age_mark) || old_address < age_mark);
 }
 
 void Heap::RecordWrite(Object* object, int offset, Object* o) {
   if (!InNewSpace(o) || !object->IsHeapObject() || InNewSpace(object)) {
     return;
   }
   RememberedSet<OLD_TO_NEW>::Insert(
       Page::FromAddress(reinterpret_cast<Address>(object)),
@@ skipping 324 matching lines @@
 
 void VerifySmisVisitor::VisitPointers(Object** start, Object** end) {
   for (Object** current = start; current < end; current++) {
     CHECK((*current)->IsSmi());
   }
 }
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_HEAP_INL_H_