[heap] Minor MC: Implement page moving

src/heap/incremental-marking.cc

 // 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.
 
 #include "src/heap/incremental-marking.h"
 
 #include "src/code-stubs.h"
 #include "src/compilation-cache.h"
 #include "src/conversions.h"
 #include "src/heap/concurrent-marking.h"
@@ skipping 803 matching lines @@
       }
       HeapObject* dest = map_word.ToForwardingAddress();
       if (ObjectMarking::IsBlack<kAtomicity>(dest, marking_state(dest))) {
         // The object is already processed by the marker.
         return nullptr;
       }
       DCHECK(ObjectMarking::IsGrey<kAtomicity>(obj, marking_state(obj)) ||
              (obj->IsFiller() &&
               ObjectMarking::IsWhite<kAtomicity>(obj, marking_state(obj))));
       return dest;
+    } else if (heap_->InToSpace(obj)) {
+      // The object may be on a page that was moved in new space.
+      DCHECK(
+          Page::FromAddress(obj->address())->IsFlagSet(Page::SWEEP_TO_ITERATE));
+      return ObjectMarking::IsBlack<kAtomicity>(obj,
+                                                MarkingState::External(obj))
+                 ? obj
+                 : nullptr;
     } else {
+      // The object may be on a page that was moved from new to old space.
+      if (Page::FromAddress(obj->address())
+              ->IsFlagSet(Page::SWEEP_TO_ITERATE)) {
+        return ObjectMarking::IsBlack<kAtomicity>(obj,
+                                                  MarkingState::External(obj))
+                   ? obj
+                   : nullptr;
+      }
       DCHECK(ObjectMarking::IsGrey<kAtomicity>(obj, marking_state(obj)) ||
              (obj->IsFiller() &&
               ObjectMarking::IsWhite<kAtomicity>(obj, marking_state(obj))) ||
              (MemoryChunk::FromAddress(obj->address())
                   ->IsFlagSet(MemoryChunk::HAS_PROGRESS_BAR) &&
               ObjectMarking::IsBlack<kAtomicity>(obj, marking_state(obj))));
       // Skip one word filler objects that appear on the
       // stack when we perform in place array shift.
       return (obj->map() == filler_map) ? nullptr : obj;
     }
@@ skipping 364 matching lines @@
   idle_marking_delay_counter_++;
 }
 
 
 void IncrementalMarking::ClearIdleMarkingDelayCounter() {
   idle_marking_delay_counter_ = 0;
 }
 
 }  // namespace internal
 }  // namespace v8