/deps/v8/src/mark-compact.cc - CSE2410 Fall 2014 Bounce - CS Projects

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       // Copyright 2012 the V8 project authors. All rights reserved.
       // Redistribution and use in source and binary forms, with or without
       // modification, are permitted provided that the following conditions are
       // met:
       //
       //     * Redistributions of source code must retain the above copyright
       //       notice, this list of conditions and the following disclaimer.
       //     * Redistributions in binary form must reproduce the above
       //       copyright notice, this list of conditions and the following
       //       disclaimer in the documentation and/or other materials provided
       //       with the distribution.
       //     * Neither the name of Google Inc. nor the names of its
       //       contributors may be used to endorse or promote products derived
       //       from this software without specific prior written permission.
       //
       // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
       // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
       // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
       // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
       // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
       // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
       // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
       // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
       // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
       // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
       // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
       #include "v8.h"
       #include "code-stubs.h"
       #include "compilation-cache.h"
       #include "cpu-profiler.h"
       #include "deoptimizer.h"
       #include "execution.h"
       #include "gdb-jit.h"
       #include "global-handles.h"
       #include "heap-profiler.h"
       #include "ic-inl.h"
       #include "incremental-marking.h"
       #include "mark-compact.h"
       #include "objects-visiting.h"
       #include "objects-visiting-inl.h"
       #include "stub-cache.h"
       #include "sweeper-thread.h"
       namespace v8 {
       namespace internal {
       const char* Marking::kWhiteBitPattern = "00";
       const char* Marking::kBlackBitPattern = "10";
       const char* Marking::kGreyBitPattern = "11";
       const char* Marking::kImpossibleBitPattern = "01";
       // -------------------------------------------------------------------------
       // MarkCompactCollector
       MarkCompactCollector::MarkCompactCollector() :  // NOLINT
       #ifdef DEBUG
             state_(IDLE),
       #endif
             sweep_precisely_(false),
             reduce_memory_footprint_(false),
             abort_incremental_marking_(false),
             marking_parity_(ODD_MARKING_PARITY),
             compacting_(false),
             was_marked_incrementally_(false),
             sweeping_pending_(false),
             sequential_sweeping_(false),
             tracer_(NULL),
             migration_slots_buffer_(NULL),
             heap_(NULL),
             code_flusher_(NULL),
             encountered_weak_collections_(NULL),
             have_code_to_deoptimize_(false) { }
       #ifdef VERIFY_HEAP
       class VerifyMarkingVisitor: public ObjectVisitor {
        public:
         explicit VerifyMarkingVisitor(Heap* heap) : heap_(heap) {}
         void VisitPointers(Object** start, Object** end) {
           for (Object** current = start; current < end; current++) {
             if ((*current)->IsHeapObject()) {
               HeapObject* object = HeapObject::cast(*current);
               CHECK(heap_->mark_compact_collector()->IsMarked(object));
+            }
+          }
+        }
         void VisitEmbeddedPointer(RelocInfo* rinfo) {
           ASSERT(rinfo->rmode() == RelocInfo::EMBEDDED_OBJECT);
           if (!Code::IsWeakEmbeddedObject(rinfo->host()->kind(),
                                           rinfo->target_object())) {
             VisitPointer(rinfo->target_object_address());
+          }
+        }
        private:
         Heap* heap_;
       };
       static void VerifyMarking(Heap* heap, Address bottom, Address top) {
         VerifyMarkingVisitor visitor(heap);
         HeapObject* object;
         Address next_object_must_be_here_or_later = bottom;
         for (Address current = bottom;
              current < top;
              current += kPointerSize) {
           object = HeapObject::FromAddress(current);
           if (MarkCompactCollector::IsMarked(object)) {
             CHECK(current >= next_object_must_be_here_or_later);
             object->Iterate(&visitor);
             next_object_must_be_here_or_later = current + object->Size();
+          }
+        }
+      }
       static void VerifyMarking(NewSpace* space) {
         Address end = space->top();
         NewSpacePageIterator it(space->bottom(), end);
         // The bottom position is at the start of its page. Allows us to use
         // page->area_start() as start of range on all pages.
         CHECK_EQ(space->bottom(),
                   NewSpacePage::FromAddress(space->bottom())->area_start());
         while (it.has_next()) {
           NewSpacePage* page = it.next();
           Address limit = it.has_next() ? page->area_end() : end;
           CHECK(limit == end || !page->Contains(end));
           VerifyMarking(space->heap(), page->area_start(), limit);
+        }
+      }
       static void VerifyMarking(PagedSpace* space) {
         PageIterator it(space);
         while (it.has_next()) {
           Page* p = it.next();
           VerifyMarking(space->heap(), p->area_start(), p->area_end());
+        }
+      }
       static void VerifyMarking(Heap* heap) {
         VerifyMarking(heap->old_pointer_space());
         VerifyMarking(heap->old_data_space());
         VerifyMarking(heap->code_space());
         VerifyMarking(heap->cell_space());
         VerifyMarking(heap->property_cell_space());
         VerifyMarking(heap->map_space());
         VerifyMarking(heap->new_space());
         VerifyMarkingVisitor visitor(heap);
         LargeObjectIterator it(heap->lo_space());
         for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
           if (MarkCompactCollector::IsMarked(obj)) {
             obj->Iterate(&visitor);
+          }
+        }
         heap->IterateStrongRoots(&visitor, VISIT_ONLY_STRONG);
+      }
       class VerifyEvacuationVisitor: public ObjectVisitor {
        public:
         void VisitPointers(Object** start, Object** end) {
           for (Object** current = start; current < end; current++) {
             if ((*current)->IsHeapObject()) {
               HeapObject* object = HeapObject::cast(*current);
               CHECK(!MarkCompactCollector::IsOnEvacuationCandidate(object));
+            }
+          }
+        }
       };
       static void VerifyEvacuation(Address bottom, Address top) {
         VerifyEvacuationVisitor visitor;
         HeapObject* object;
         Address next_object_must_be_here_or_later = bottom;
         for (Address current = bottom;
              current < top;
              current += kPointerSize) {
           object = HeapObject::FromAddress(current);
           if (MarkCompactCollector::IsMarked(object)) {
             CHECK(current >= next_object_must_be_here_or_later);
             object->Iterate(&visitor);
             next_object_must_be_here_or_later = current + object->Size();
+          }
+        }
+      }
       static void VerifyEvacuation(NewSpace* space) {
         NewSpacePageIterator it(space->bottom(), space->top());
         VerifyEvacuationVisitor visitor;
         while (it.has_next()) {
           NewSpacePage* page = it.next();
           Address current = page->area_start();
           Address limit = it.has_next() ? page->area_end() : space->top();
           CHECK(limit == space->top() || !page->Contains(space->top()));
           while (current < limit) {
             HeapObject* object = HeapObject::FromAddress(current);
             object->Iterate(&visitor);
             current += object->Size();
+          }
+        }
+      }
       static void VerifyEvacuation(PagedSpace* space) {
         PageIterator it(space);
         while (it.has_next()) {
           Page* p = it.next();
           if (p->IsEvacuationCandidate()) continue;
           VerifyEvacuation(p->area_start(), p->area_end());
+        }
+      }
       static void VerifyEvacuation(Heap* heap) {
         VerifyEvacuation(heap->old_pointer_space());
         VerifyEvacuation(heap->old_data_space());
         VerifyEvacuation(heap->code_space());
         VerifyEvacuation(heap->cell_space());
         VerifyEvacuation(heap->property_cell_space());
         VerifyEvacuation(heap->map_space());
         VerifyEvacuation(heap->new_space());
         VerifyEvacuationVisitor visitor;
         heap->IterateStrongRoots(&visitor, VISIT_ALL);
+      }
       #endif  // VERIFY_HEAP
       #ifdef DEBUG
       class VerifyNativeContextSeparationVisitor: public ObjectVisitor {
        public:
         VerifyNativeContextSeparationVisitor() : current_native_context_(NULL) {}
         void VisitPointers(Object** start, Object** end) {
           for (Object** current = start; current < end; current++) {
             if ((*current)->IsHeapObject()) {
               HeapObject* object = HeapObject::cast(*current);
               if (object->IsString()) continue;
               switch (object->map()->instance_type()) {
                 case JS_FUNCTION_TYPE:
                   CheckContext(JSFunction::cast(object)->context());
                   break;
                 case JS_GLOBAL_PROXY_TYPE:
                   CheckContext(JSGlobalProxy::cast(object)->native_context());
                   break;
                 case JS_GLOBAL_OBJECT_TYPE:
                 case JS_BUILTINS_OBJECT_TYPE:
                   CheckContext(GlobalObject::cast(object)->native_context());
                   break;
                 case JS_ARRAY_TYPE:
                 case JS_DATE_TYPE:
                 case JS_OBJECT_TYPE:
                 case JS_REGEXP_TYPE:
                   VisitPointer(HeapObject::RawField(object, JSObject::kMapOffset));
                   break;
                 case MAP_TYPE:
                   VisitPointer(HeapObject::RawField(object, Map::kPrototypeOffset));
                   VisitPointer(HeapObject::RawField(object, Map::kConstructorOffset));
                   break;
                 case FIXED_ARRAY_TYPE:
                   if (object->IsContext()) {
                     CheckContext(object);
                   } else {
                     FixedArray* array = FixedArray::cast(object);
                     int length = array->length();
                     // Set array length to zero to prevent cycles while iterating
                     // over array bodies, this is easier than intrusive marking.
                     array->set_length(0);
                     array->IterateBody(
                         FIXED_ARRAY_TYPE, FixedArray::SizeFor(length), this);
                     array->set_length(length);
+                  }
                   break;
                 case CELL_TYPE:
                 case JS_PROXY_TYPE:
                 case JS_VALUE_TYPE:
                 case TYPE_FEEDBACK_INFO_TYPE:
                   object->Iterate(this);
                   break;
                 case DECLARED_ACCESSOR_INFO_TYPE:
                 case EXECUTABLE_ACCESSOR_INFO_TYPE:
                 case BYTE_ARRAY_TYPE:
                 case CALL_HANDLER_INFO_TYPE:
                 case CODE_TYPE:
                 case FIXED_DOUBLE_ARRAY_TYPE:
                 case HEAP_NUMBER_TYPE:
                 case INTERCEPTOR_INFO_TYPE:
                 case ODDBALL_TYPE:
                 case SCRIPT_TYPE:
                 case SHARED_FUNCTION_INFO_TYPE:
                   break;
                 default:
                   UNREACHABLE();
+              }
+            }
+          }
+        }
        private:
         void CheckContext(Object* context) {
           if (!context->IsContext()) return;
           Context* native_context = Context::cast(context)->native_context();
           if (current_native_context_ == NULL) {
             current_native_context_ = native_context;
           } else {
             CHECK_EQ(current_native_context_, native_context);
+          }
+        }
         Context* current_native_context_;
       };
       static void VerifyNativeContextSeparation(Heap* heap) {
         HeapObjectIterator it(heap->code_space());
         for (Object* object = it.Next(); object != NULL; object = it.Next()) {
           VerifyNativeContextSeparationVisitor visitor;
           Code::cast(object)->CodeIterateBody(&visitor);
+        }
+      }
       #endif
       void MarkCompactCollector::TearDown() {
         AbortCompaction();
+      }
       void MarkCompactCollector::AddEvacuationCandidate(Page* p) {
         p->MarkEvacuationCandidate();
         evacuation_candidates_.Add(p);
+      }
       static void TraceFragmentation(PagedSpace* space) {
         int number_of_pages = space->CountTotalPages();
         intptr_t reserved = (number_of_pages * space->AreaSize());
         intptr_t free = reserved - space->SizeOfObjects();
         PrintF("[%s]: %d pages, %d (%.1f%%) free\n",
                AllocationSpaceName(space->identity()),
                number_of_pages,
                static_cast<int>(free),
                static_cast<double>(free) * 100 / reserved);
+      }
       bool MarkCompactCollector::StartCompaction(CompactionMode mode) {
         if (!compacting_) {
           ASSERT(evacuation_candidates_.length() == 0);
       #ifdef ENABLE_GDB_JIT_INTERFACE
           // If GDBJIT interface is active disable compaction.
           if (FLAG_gdbjit) return false;
       #endif
           CollectEvacuationCandidates(heap()->old_pointer_space());
           CollectEvacuationCandidates(heap()->old_data_space());
           if (FLAG_compact_code_space &&
               (mode == NON_INCREMENTAL_COMPACTION ||
                FLAG_incremental_code_compaction)) {
             CollectEvacuationCandidates(heap()->code_space());
           } else if (FLAG_trace_fragmentation) {
             TraceFragmentation(heap()->code_space());
+          }
           if (FLAG_trace_fragmentation) {
             TraceFragmentation(heap()->map_space());
             TraceFragmentation(heap()->cell_space());
             TraceFragmentation(heap()->property_cell_space());
+          }
           heap()->old_pointer_space()->EvictEvacuationCandidatesFromFreeLists();
           heap()->old_data_space()->EvictEvacuationCandidatesFromFreeLists();
           heap()->code_space()->EvictEvacuationCandidatesFromFreeLists();
           compacting_ = evacuation_candidates_.length() > 0;
+        }
         return compacting_;
+      }
       void MarkCompactCollector::CollectGarbage() {
         // Make sure that Prepare() has been called. The individual steps below will
         // update the state as they proceed.
         ASSERT(state_ == PREPARE_GC);
         ASSERT(encountered_weak_collections_ == Smi::FromInt(0));
         heap()->allocation_mementos_found_ = 0;
         MarkLiveObjects();
         ASSERT(heap_->incremental_marking()->IsStopped());
         if (FLAG_collect_maps) ClearNonLiveReferences();
         ClearWeakCollections();
       #ifdef VERIFY_HEAP
         if (FLAG_verify_heap) {
           VerifyMarking(heap_);
+        }
       #endif
         SweepSpaces();
         if (!FLAG_collect_maps) ReattachInitialMaps();
       #ifdef DEBUG
         if (FLAG_verify_native_context_separation) {
           VerifyNativeContextSeparation(heap_);
+        }
       #endif
       #ifdef VERIFY_HEAP
         if (heap()->weak_embedded_objects_verification_enabled()) {
           VerifyWeakEmbeddedObjectsInOptimizedCode();
+        }
         if (FLAG_collect_maps && FLAG_omit_map_checks_for_leaf_maps) {
           VerifyOmittedMapChecks();
+        }
       #endif
         Finish();
         if (marking_parity_ == EVEN_MARKING_PARITY) {
           marking_parity_ = ODD_MARKING_PARITY;
         } else {
           ASSERT(marking_parity_ == ODD_MARKING_PARITY);
           marking_parity_ = EVEN_MARKING_PARITY;
+        }
         if (FLAG_trace_track_allocation_sites &&
             heap()->allocation_mementos_found_ > 0) {
           PrintF("AllocationMementos found during mark-sweep = %d\n",
                  heap()->allocation_mementos_found_);
+        }
         tracer_ = NULL;
+      }
       #ifdef VERIFY_HEAP
       void MarkCompactCollector::VerifyMarkbitsAreClean(PagedSpace* space) {
         PageIterator it(space);
         while (it.has_next()) {
           Page* p = it.next();
           CHECK(p->markbits()->IsClean());
           CHECK_EQ(0, p->LiveBytes());
+        }
+      }
       void MarkCompactCollector::VerifyMarkbitsAreClean(NewSpace* space) {
         NewSpacePageIterator it(space->bottom(), space->top());
         while (it.has_next()) {
           NewSpacePage* p = it.next();
           CHECK(p->markbits()->IsClean());
           CHECK_EQ(0, p->LiveBytes());
+        }
+      }
       void MarkCompactCollector::VerifyMarkbitsAreClean() {
         VerifyMarkbitsAreClean(heap_->old_pointer_space());
         VerifyMarkbitsAreClean(heap_->old_data_space());
         VerifyMarkbitsAreClean(heap_->code_space());
         VerifyMarkbitsAreClean(heap_->cell_space());
         VerifyMarkbitsAreClean(heap_->property_cell_space());
         VerifyMarkbitsAreClean(heap_->map_space());
         VerifyMarkbitsAreClean(heap_->new_space());
         LargeObjectIterator it(heap_->lo_space());
         for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
           MarkBit mark_bit = Marking::MarkBitFrom(obj);
           CHECK(Marking::IsWhite(mark_bit));
           CHECK_EQ(0, Page::FromAddress(obj->address())->LiveBytes());
+        }
+      }
       void MarkCompactCollector::VerifyWeakEmbeddedObjectsInOptimizedCode() {
         HeapObjectIterator code_iterator(heap()->code_space());
         for (HeapObject* obj = code_iterator.Next();
              obj != NULL;
              obj = code_iterator.Next()) {
           Code* code = Code::cast(obj);
           if (code->kind() != Code::OPTIMIZED_FUNCTION) continue;
           if (WillBeDeoptimized(code)) continue;
           code->VerifyEmbeddedObjectsDependency();
+        }
+      }
       void MarkCompactCollector::VerifyOmittedMapChecks() {
         HeapObjectIterator iterator(heap()->map_space());
         for (HeapObject* obj = iterator.Next();
              obj != NULL;
              obj = iterator.Next()) {
           Map* map = Map::cast(obj);
           map->VerifyOmittedMapChecks();
+        }
+      }
       #endif  // VERIFY_HEAP
       static void ClearMarkbitsInPagedSpace(PagedSpace* space) {
         PageIterator it(space);
         while (it.has_next()) {
           Bitmap::Clear(it.next());
+        }
+      }
       static void ClearMarkbitsInNewSpace(NewSpace* space) {
         NewSpacePageIterator it(space->ToSpaceStart(), space->ToSpaceEnd());
         while (it.has_next()) {
           Bitmap::Clear(it.next());
+        }
+      }
       void MarkCompactCollector::ClearMarkbits() {
         ClearMarkbitsInPagedSpace(heap_->code_space());
         ClearMarkbitsInPagedSpace(heap_->map_space());
         ClearMarkbitsInPagedSpace(heap_->old_pointer_space());
         ClearMarkbitsInPagedSpace(heap_->old_data_space());
         ClearMarkbitsInPagedSpace(heap_->cell_space());
         ClearMarkbitsInPagedSpace(heap_->property_cell_space());
         ClearMarkbitsInNewSpace(heap_->new_space());
         LargeObjectIterator it(heap_->lo_space());
         for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
           MarkBit mark_bit = Marking::MarkBitFrom(obj);
           mark_bit.Clear();
           mark_bit.Next().Clear();
           Page::FromAddress(obj->address())->ResetProgressBar();
           Page::FromAddress(obj->address())->ResetLiveBytes();
+        }
+      }
       void MarkCompactCollector::StartSweeperThreads() {
         sweeping_pending_ = true;
         for (int i = 0; i < FLAG_sweeper_threads; i++) {
           isolate()->sweeper_threads()[i]->StartSweeping();
+        }
+      }
       void MarkCompactCollector::WaitUntilSweepingCompleted() {
         ASSERT(sweeping_pending_ == true);
         for (int i = 0; i < FLAG_sweeper_threads; i++) {
           isolate()->sweeper_threads()[i]->WaitForSweeperThread();
+        }
         sweeping_pending_ = false;
         StealMemoryFromSweeperThreads(heap()->paged_space(OLD_DATA_SPACE));
         StealMemoryFromSweeperThreads(heap()->paged_space(OLD_POINTER_SPACE));
         heap()->paged_space(OLD_DATA_SPACE)->ResetUnsweptFreeBytes();
         heap()->paged_space(OLD_POINTER_SPACE)->ResetUnsweptFreeBytes();
+      }
       intptr_t MarkCompactCollector::
                    StealMemoryFromSweeperThreads(PagedSpace* space) {
         intptr_t freed_bytes = 0;
         for (int i = 0; i < FLAG_sweeper_threads; i++) {
           freed_bytes += isolate()->sweeper_threads()[i]->StealMemory(space);
+        }
         space->AddToAccountingStats(freed_bytes);
         space->DecrementUnsweptFreeBytes(freed_bytes);
         return freed_bytes;
+      }
       bool MarkCompactCollector::AreSweeperThreadsActivated() {
         return isolate()->sweeper_threads() != NULL;
+      }
       bool MarkCompactCollector::IsConcurrentSweepingInProgress() {
         return sweeping_pending_;
+      }
       bool Marking::TransferMark(Address old_start, Address new_start) {
         // This is only used when resizing an object.
         ASSERT(MemoryChunk::FromAddress(old_start) ==
                MemoryChunk::FromAddress(new_start));
         // If the mark doesn't move, we don't check the color of the object.
         // It doesn't matter whether the object is black, since it hasn't changed
         // size, so the adjustment to the live data count will be zero anyway.
         if (old_start == new_start) return false;
         MarkBit new_mark_bit = MarkBitFrom(new_start);
         MarkBit old_mark_bit = MarkBitFrom(old_start);
       #ifdef DEBUG
         ObjectColor old_color = Color(old_mark_bit);
       #endif
         if (Marking::IsBlack(old_mark_bit)) {
           old_mark_bit.Clear();
           ASSERT(IsWhite(old_mark_bit));
           Marking::MarkBlack(new_mark_bit);
           return true;
         } else if (Marking::IsGrey(old_mark_bit)) {
           ASSERT(heap_->incremental_marking()->IsMarking());
           old_mark_bit.Clear();
           old_mark_bit.Next().Clear();
           ASSERT(IsWhite(old_mark_bit));
           heap_->incremental_marking()->WhiteToGreyAndPush(
               HeapObject::FromAddress(new_start), new_mark_bit);
           heap_->incremental_marking()->RestartIfNotMarking();
+        }
       #ifdef DEBUG
         ObjectColor new_color = Color(new_mark_bit);
         ASSERT(new_color == old_color);
       #endif
         return false;
+      }
       const char* AllocationSpaceName(AllocationSpace space) {
         switch (space) {
           case NEW_SPACE: return "NEW_SPACE";
           case OLD_POINTER_SPACE: return "OLD_POINTER_SPACE";
           case OLD_DATA_SPACE: return "OLD_DATA_SPACE";
           case CODE_SPACE: return "CODE_SPACE";
           case MAP_SPACE: return "MAP_SPACE";
           case CELL_SPACE: return "CELL_SPACE";
           case PROPERTY_CELL_SPACE:
             return "PROPERTY_CELL_SPACE";
           case LO_SPACE: return "LO_SPACE";
           default:
             UNREACHABLE();
+        }
         return NULL;
+      }
       // Returns zero for pages that have so little fragmentation that it is not
       // worth defragmenting them.  Otherwise a positive integer that gives an
       // estimate of fragmentation on an arbitrary scale.
       static int FreeListFragmentation(PagedSpace* space, Page* p) {
         // If page was not swept then there are no free list items on it.
         if (!p->WasSwept()) {
           if (FLAG_trace_fragmentation) {
             PrintF("%p [%s]: %d bytes live (unswept)\n",
                    reinterpret_cast<void*>(p),
                    AllocationSpaceName(space->identity()),
                    p->LiveBytes());
+          }
           return 0;
+        }
         PagedSpace::SizeStats sizes;
         space->ObtainFreeListStatistics(p, &sizes);
         intptr_t ratio;
         intptr_t ratio_threshold;
         intptr_t area_size = space->AreaSize();
         if (space->identity() == CODE_SPACE) {
           ratio = (sizes.medium_size_ * 10 + sizes.large_size_ * 2) * 100 /
               area_size;
           ratio_threshold = 10;
         } else {
           ratio = (sizes.small_size_ * 5 + sizes.medium_size_) * 100 /
               area_size;
           ratio_threshold = 15;
+        }
         if (FLAG_trace_fragmentation) {
           PrintF("%p [%s]: %d (%.2f%%) %d (%.2f%%) %d (%.2f%%) %d (%.2f%%) %s\n",
                  reinterpret_cast<void*>(p),
                  AllocationSpaceName(space->identity()),
                  static_cast<int>(sizes.small_size_),
                  static_cast<double>(sizes.small_size_ * 100) /
                  area_size,
                  static_cast<int>(sizes.medium_size_),
                  static_cast<double>(sizes.medium_size_ * 100) /
                  area_size,
                  static_cast<int>(sizes.large_size_),
                  static_cast<double>(sizes.large_size_ * 100) /
                  area_size,
                  static_cast<int>(sizes.huge_size_),
                  static_cast<double>(sizes.huge_size_ * 100) /
                  area_size,
                  (ratio > ratio_threshold) ? "[fragmented]" : "");
+        }
         if (FLAG_always_compact && sizes.Total() != area_size) {
           return 1;
+        }
         if (ratio <= ratio_threshold) return 0;  // Not fragmented.
         return static_cast<int>(ratio - ratio_threshold);
+      }
       void MarkCompactCollector::CollectEvacuationCandidates(PagedSpace* space) {
         ASSERT(space->identity() == OLD_POINTER_SPACE ||
                space->identity() == OLD_DATA_SPACE ||
                space->identity() == CODE_SPACE);
         static const int kMaxMaxEvacuationCandidates = 1000;
         int number_of_pages = space->CountTotalPages();
         int max_evacuation_candidates =
             static_cast<int>(sqrt(number_of_pages / 2.0) + 1);
         if (FLAG_stress_compaction || FLAG_always_compact) {
           max_evacuation_candidates = kMaxMaxEvacuationCandidates;
+        }
         class Candidate {
          public:
           Candidate() : fragmentation_(0), page_(NULL) { }
           Candidate(int f, Page* p) : fragmentation_(f), page_(p) { }
           int fragmentation() { return fragmentation_; }
           Page* page() { return page_; }
          private:
           int fragmentation_;
           Page* page_;
         };
         enum CompactionMode {
           COMPACT_FREE_LISTS,
           REDUCE_MEMORY_FOOTPRINT
         };
         CompactionMode mode = COMPACT_FREE_LISTS;
         intptr_t reserved = number_of_pages * space->AreaSize();
         intptr_t over_reserved = reserved - space->SizeOfObjects();
         static const intptr_t kFreenessThreshold = 50;
         if (reduce_memory_footprint_ && over_reserved >= space->AreaSize()) {
           // If reduction of memory footprint was requested, we are aggressive
           // about choosing pages to free.  We expect that half-empty pages
           // are easier to compact so slightly bump the limit.
           mode = REDUCE_MEMORY_FOOTPRINT;
           max_evacuation_candidates += 2;
+        }
         if (over_reserved > reserved / 3 && over_reserved >= 2 * space->AreaSize()) {
           // If over-usage is very high (more than a third of the space), we
           // try to free all mostly empty pages.  We expect that almost empty
           // pages are even easier to compact so bump the limit even more.
           mode = REDUCE_MEMORY_FOOTPRINT;
           max_evacuation_candidates *= 2;
+        }
         if (FLAG_trace_fragmentation && mode == REDUCE_MEMORY_FOOTPRINT) {
           PrintF("Estimated over reserved memory: %.1f / %.1f MB (threshold %d), "
                  "evacuation candidate limit: %d\n",
                  static_cast<double>(over_reserved) / MB,
                  static_cast<double>(reserved) / MB,
                  static_cast<int>(kFreenessThreshold),
                  max_evacuation_candidates);
+        }
         intptr_t estimated_release = 0;
         Candidate candidates[kMaxMaxEvacuationCandidates];
         max_evacuation_candidates =
             Min(kMaxMaxEvacuationCandidates, max_evacuation_candidates);
         int count = 0;
         int fragmentation = 0;
         Candidate* least = NULL;
         PageIterator it(space);
         if (it.has_next()) it.next();  // Never compact the first page.
         while (it.has_next()) {
           Page* p = it.next();
           p->ClearEvacuationCandidate();
           if (FLAG_stress_compaction) {
             unsigned int counter = space->heap()->ms_count();
             uintptr_t page_number = reinterpret_cast<uintptr_t>(p) >> kPageSizeBits;
             if ((counter & 1) == (page_number & 1)) fragmentation = 1;
           } else if (mode == REDUCE_MEMORY_FOOTPRINT) {
             // Don't try to release too many pages.
             if (estimated_release >= over_reserved) {
               continue;
+            }
             intptr_t free_bytes = 0;
             if (!p->WasSwept()) {
               free_bytes = (p->area_size() - p->LiveBytes());
             } else {
               PagedSpace::SizeStats sizes;
               space->ObtainFreeListStatistics(p, &sizes);
               free_bytes = sizes.Total();
+            }
             int free_pct = static_cast<int>(free_bytes * 100) / p->area_size();
             if (free_pct >= kFreenessThreshold) {
               estimated_release += free_bytes;
               fragmentation = free_pct;
             } else {
               fragmentation = 0;
+            }
             if (FLAG_trace_fragmentation) {
               PrintF("%p [%s]: %d (%.2f%%) free %s\n",
                      reinterpret_cast<void*>(p),
                      AllocationSpaceName(space->identity()),
                      static_cast<int>(free_bytes),
                      static_cast<double>(free_bytes * 100) / p->area_size(),
                      (fragmentation > 0) ? "[fragmented]" : "");
+            }
           } else {
             fragmentation = FreeListFragmentation(space, p);
+          }
           if (fragmentation != 0) {
             if (count < max_evacuation_candidates) {
               candidates[count++] = Candidate(fragmentation, p);
             } else {
               if (least == NULL) {
                 for (int i = 0; i < max_evacuation_candidates; i++) {
                   if (least == NULL ||
                       candidates[i].fragmentation() < least->fragmentation()) {
                     least = candidates + i;
+                  }
+                }
+              }
               if (least->fragmentation() < fragmentation) {
                 *least = Candidate(fragmentation, p);
                 least = NULL;
+              }
+            }
+          }
+        }
         for (int i = 0; i < count; i++) {
           AddEvacuationCandidate(candidates[i].page());
+        }
         if (count > 0 && FLAG_trace_fragmentation) {
           PrintF("Collected %d evacuation candidates for space %s\n",
                  count,
                  AllocationSpaceName(space->identity()));
+        }
+      }
       void MarkCompactCollector::AbortCompaction() {
         if (compacting_) {
           int npages = evacuation_candidates_.length();
           for (int i = 0; i < npages; i++) {
             Page* p = evacuation_candidates_[i];
             slots_buffer_allocator_.DeallocateChain(p->slots_buffer_address());
             p->ClearEvacuationCandidate();
             p->ClearFlag(MemoryChunk::RESCAN_ON_EVACUATION);
+          }
           compacting_ = false;
           evacuation_candidates_.Rewind(0);
           invalidated_code_.Rewind(0);
+        }
         ASSERT_EQ(0, evacuation_candidates_.length());
+      }
       void MarkCompactCollector::Prepare(GCTracer* tracer) {
         was_marked_incrementally_ = heap()->incremental_marking()->IsMarking();
         // Rather than passing the tracer around we stash it in a static member
         // variable.
         tracer_ = tracer;
       #ifdef DEBUG
         ASSERT(state_ == IDLE);
         state_ = PREPARE_GC;
       #endif
         ASSERT(!FLAG_never_compact || !FLAG_always_compact);
         if (IsConcurrentSweepingInProgress()) {
           // Instead of waiting we could also abort the sweeper threads here.
           WaitUntilSweepingCompleted();
+        }
         // Clear marking bits if incremental marking is aborted.
         if (was_marked_incrementally_ && abort_incremental_marking_) {
           heap()->incremental_marking()->Abort();
           ClearMarkbits();
           AbortCompaction();
           was_marked_incrementally_ = false;
+        }
         // Don't start compaction if we are in the middle of incremental
         // marking cycle. We did not collect any slots.
         if (!FLAG_never_compact && !was_marked_incrementally_) {
           StartCompaction(NON_INCREMENTAL_COMPACTION);
+        }
         PagedSpaces spaces(heap());
         for (PagedSpace* space = spaces.next();
              space != NULL;
              space = spaces.next()) {
           space->PrepareForMarkCompact();
+        }
       #ifdef VERIFY_HEAP
         if (!was_marked_incrementally_ && FLAG_verify_heap) {
           VerifyMarkbitsAreClean();
+        }
       #endif
+      }
       void MarkCompactCollector::Finish() {
       #ifdef DEBUG
         ASSERT(state_ == SWEEP_SPACES || state_ == RELOCATE_OBJECTS);
         state_ = IDLE;
       #endif
         // The stub cache is not traversed during GC; clear the cache to
         // force lazy re-initialization of it. This must be done after the
         // GC, because it relies on the new address of certain old space
         // objects (empty string, illegal builtin).
         isolate()->stub_cache()->Clear();
         if (have_code_to_deoptimize_) {
           // Some code objects were marked for deoptimization during the GC.
           Deoptimizer::DeoptimizeMarkedCode(isolate());
           have_code_to_deoptimize_ = false;
+        }
+      }
       // -------------------------------------------------------------------------
       // Phase 1: tracing and marking live objects.
       //   before: all objects are in normal state.
       //   after: a live object's map pointer is marked as '00'.
       // Marking all live objects in the heap as part of mark-sweep or mark-compact
       // collection.  Before marking, all objects are in their normal state.  After
       // marking, live objects' map pointers are marked indicating that the object
       // has been found reachable.
       //
       // The marking algorithm is a (mostly) depth-first (because of possible stack
       // overflow) traversal of the graph of objects reachable from the roots.  It
       // uses an explicit stack of pointers rather than recursion.  The young
       // generation's inactive ('from') space is used as a marking stack.  The
       // objects in the marking stack are the ones that have been reached and marked
       // but their children have not yet been visited.
       //
       // The marking stack can overflow during traversal.  In that case, we set an
       // overflow flag.  When the overflow flag is set, we continue marking objects
       // reachable from the objects on the marking stack, but no longer push them on
       // the marking stack.  Instead, we mark them as both marked and overflowed.
       // When the stack is in the overflowed state, objects marked as overflowed
       // have been reached and marked but their children have not been visited yet.
       // After emptying the marking stack, we clear the overflow flag and traverse
       // the heap looking for objects marked as overflowed, push them on the stack,
       // and continue with marking.  This process repeats until all reachable
       // objects have been marked.
       void CodeFlusher::ProcessJSFunctionCandidates() {
         Code* lazy_compile = isolate_->builtins()->builtin(Builtins::kLazyCompile);
         Object* undefined = isolate_->heap()->undefined_value();
         JSFunction* candidate = jsfunction_candidates_head_;
         JSFunction* next_candidate;
         while (candidate != NULL) {
           next_candidate = GetNextCandidate(candidate);
           ClearNextCandidate(candidate, undefined);
           SharedFunctionInfo* shared = candidate->shared();
           Code* code = shared->code();
           MarkBit code_mark = Marking::MarkBitFrom(code);
           if (!code_mark.Get()) {
             if (FLAG_trace_code_flushing && shared->is_compiled()) {
               PrintF("[code-flushing clears: ");
               shared->ShortPrint();
               PrintF(" - age: %d]\n", code->GetAge());
+            }
             shared->set_code(lazy_compile);
             candidate->set_code(lazy_compile);
           } else {
             candidate->set_code(code);
+          }
           // We are in the middle of a GC cycle so the write barrier in the code
           // setter did not record the slot update and we have to do that manually.
           Address slot = candidate->address() + JSFunction::kCodeEntryOffset;
           Code* target = Code::cast(Code::GetObjectFromEntryAddress(slot));
           isolate_->heap()->mark_compact_collector()->
               RecordCodeEntrySlot(slot, target);
           Object** shared_code_slot =
               HeapObject::RawField(shared, SharedFunctionInfo::kCodeOffset);
           isolate_->heap()->mark_compact_collector()->
               RecordSlot(shared_code_slot, shared_code_slot, *shared_code_slot);
           candidate = next_candidate;
+        }
         jsfunction_candidates_head_ = NULL;
+      }
       void CodeFlusher::ProcessSharedFunctionInfoCandidates() {
         Code* lazy_compile = isolate_->builtins()->builtin(Builtins::kLazyCompile);
         SharedFunctionInfo* candidate = shared_function_info_candidates_head_;
         SharedFunctionInfo* next_candidate;
         while (candidate != NULL) {
           next_candidate = GetNextCandidate(candidate);
           ClearNextCandidate(candidate);
           Code* code = candidate->code();
           MarkBit code_mark = Marking::MarkBitFrom(code);
           if (!code_mark.Get()) {
             if (FLAG_trace_code_flushing && candidate->is_compiled()) {
               PrintF("[code-flushing clears: ");
               candidate->ShortPrint();
               PrintF(" - age: %d]\n", code->GetAge());
+            }
             candidate->set_code(lazy_compile);
+          }
           Object** code_slot =
               HeapObject::RawField(candidate, SharedFunctionInfo::kCodeOffset);
           isolate_->heap()->mark_compact_collector()->
               RecordSlot(code_slot, code_slot, *code_slot);
           candidate = next_candidate;
+        }
         shared_function_info_candidates_head_ = NULL;
+      }
       void CodeFlusher::ProcessOptimizedCodeMaps() {
         static const int kEntriesStart = SharedFunctionInfo::kEntriesStart;
         static const int kEntryLength = SharedFunctionInfo::kEntryLength;
         static const int kContextOffset = 0;
         static const int kCodeOffset = 1;
         static const int kLiteralsOffset = 2;
         STATIC_ASSERT(kEntryLength == 3);
         SharedFunctionInfo* holder = optimized_code_map_holder_head_;
         SharedFunctionInfo* next_holder;
         while (holder != NULL) {
           next_holder = GetNextCodeMap(holder);
           ClearNextCodeMap(holder);
           FixedArray* code_map = FixedArray::cast(holder->optimized_code_map());
           int new_length = kEntriesStart;
           int old_length = code_map->length();
           for (int i = kEntriesStart; i < old_length; i += kEntryLength) {
             Code* code = Code::cast(code_map->get(i + kCodeOffset));
             MarkBit code_mark = Marking::MarkBitFrom(code);
             if (!code_mark.Get()) {
               continue;
+            }
             // Update and record the context slot in the optimized code map.
             Object** context_slot = HeapObject::RawField(code_map,
                 FixedArray::OffsetOfElementAt(new_length));
             code_map->set(new_length++, code_map->get(i + kContextOffset));
             ASSERT(Marking::IsBlack(
                 Marking::MarkBitFrom(HeapObject::cast(*context_slot))));
             isolate_->heap()->mark_compact_collector()->
                 RecordSlot(context_slot, context_slot, *context_slot);
             // Update and record the code slot in the optimized code map.
             Object** code_slot = HeapObject::RawField(code_map,
                 FixedArray::OffsetOfElementAt(new_length));
             code_map->set(new_length++, code_map->get(i + kCodeOffset));
             ASSERT(Marking::IsBlack(
                 Marking::MarkBitFrom(HeapObject::cast(*code_slot))));
             isolate_->heap()->mark_compact_collector()->
                 RecordSlot(code_slot, code_slot, *code_slot);
             // Update and record the literals slot in the optimized code map.
             Object** literals_slot = HeapObject::RawField(code_map,
                 FixedArray::OffsetOfElementAt(new_length));
             code_map->set(new_length++, code_map->get(i + kLiteralsOffset));
             ASSERT(Marking::IsBlack(
                 Marking::MarkBitFrom(HeapObject::cast(*literals_slot))));
             isolate_->heap()->mark_compact_collector()->
                 RecordSlot(literals_slot, literals_slot, *literals_slot);
+          }
           // Trim the optimized code map if entries have been removed.
           if (new_length < old_length) {
             holder->TrimOptimizedCodeMap(old_length - new_length);
+          }
           holder = next_holder;
+        }
         optimized_code_map_holder_head_ = NULL;
+      }
       void CodeFlusher::EvictCandidate(SharedFunctionInfo* shared_info) {
         // Make sure previous flushing decisions are revisited.
         isolate_->heap()->incremental_marking()->RecordWrites(shared_info);
         if (FLAG_trace_code_flushing) {
           PrintF("[code-flushing abandons function-info: ");
           shared_info->ShortPrint();
           PrintF("]\n");
+        }
         SharedFunctionInfo* candidate = shared_function_info_candidates_head_;
         SharedFunctionInfo* next_candidate;
         if (candidate == shared_info) {
           next_candidate = GetNextCandidate(shared_info);
           shared_function_info_candidates_head_ = next_candidate;
           ClearNextCandidate(shared_info);
         } else {
           while (candidate != NULL) {
             next_candidate = GetNextCandidate(candidate);
             if (next_candidate == shared_info) {
               next_candidate = GetNextCandidate(shared_info);
               SetNextCandidate(candidate, next_candidate);
               ClearNextCandidate(shared_info);
               break;
+            }
             candidate = next_candidate;
+          }
+        }
+      }
       void CodeFlusher::EvictCandidate(JSFunction* function) {
         ASSERT(!function->next_function_link()->IsUndefined());
         Object* undefined = isolate_->heap()->undefined_value();
         // Make sure previous flushing decisions are revisited.
         isolate_->heap()->incremental_marking()->RecordWrites(function);
         isolate_->heap()->incremental_marking()->RecordWrites(function->shared());
         if (FLAG_trace_code_flushing) {
           PrintF("[code-flushing abandons closure: ");
           function->shared()->ShortPrint();
           PrintF("]\n");
+        }
         JSFunction* candidate = jsfunction_candidates_head_;
         JSFunction* next_candidate;
         if (candidate == function) {
           next_candidate = GetNextCandidate(function);
           jsfunction_candidates_head_ = next_candidate;
           ClearNextCandidate(function, undefined);
         } else {
           while (candidate != NULL) {
             next_candidate = GetNextCandidate(candidate);
             if (next_candidate == function) {
               next_candidate = GetNextCandidate(function);
               SetNextCandidate(candidate, next_candidate);
               ClearNextCandidate(function, undefined);
               break;
+            }
             candidate = next_candidate;
+          }
+        }
+      }
       void CodeFlusher::EvictOptimizedCodeMap(SharedFunctionInfo* code_map_holder) {
         ASSERT(!FixedArray::cast(code_map_holder->optimized_code_map())->
                get(SharedFunctionInfo::kNextMapIndex)->IsUndefined());
         // Make sure previous flushing decisions are revisited.
         isolate_->heap()->incremental_marking()->RecordWrites(code_map_holder);
         if (FLAG_trace_code_flushing) {
           PrintF("[code-flushing abandons code-map: ");
           code_map_holder->ShortPrint();
           PrintF("]\n");
+        }
         SharedFunctionInfo* holder = optimized_code_map_holder_head_;
         SharedFunctionInfo* next_holder;
         if (holder == code_map_holder) {
           next_holder = GetNextCodeMap(code_map_holder);
           optimized_code_map_holder_head_ = next_holder;
           ClearNextCodeMap(code_map_holder);
         } else {
           while (holder != NULL) {
             next_holder = GetNextCodeMap(holder);
             if (next_holder == code_map_holder) {
               next_holder = GetNextCodeMap(code_map_holder);
               SetNextCodeMap(holder, next_holder);
               ClearNextCodeMap(code_map_holder);
               break;
+            }
             holder = next_holder;
+          }
+        }
+      }
       void CodeFlusher::EvictJSFunctionCandidates() {
         JSFunction* candidate = jsfunction_candidates_head_;
         JSFunction* next_candidate;
         while (candidate != NULL) {
           next_candidate = GetNextCandidate(candidate);
           EvictCandidate(candidate);
           candidate = next_candidate;
+        }
         ASSERT(jsfunction_candidates_head_ == NULL);
+      }
       void CodeFlusher::EvictSharedFunctionInfoCandidates() {
         SharedFunctionInfo* candidate = shared_function_info_candidates_head_;
         SharedFunctionInfo* next_candidate;
         while (candidate != NULL) {
           next_candidate = GetNextCandidate(candidate);
           EvictCandidate(candidate);
           candidate = next_candidate;
+        }
         ASSERT(shared_function_info_candidates_head_ == NULL);
+      }
       void CodeFlusher::EvictOptimizedCodeMaps() {
         SharedFunctionInfo* holder = optimized_code_map_holder_head_;
         SharedFunctionInfo* next_holder;
         while (holder != NULL) {
           next_holder = GetNextCodeMap(holder);
           EvictOptimizedCodeMap(holder);
           holder = next_holder;
+        }
         ASSERT(optimized_code_map_holder_head_ == NULL);
+      }
       void CodeFlusher::IteratePointersToFromSpace(ObjectVisitor* v) {
         Heap* heap = isolate_->heap();
         JSFunction** slot = &jsfunction_candidates_head_;
         JSFunction* candidate = jsfunction_candidates_head_;
         while (candidate != NULL) {
           if (heap->InFromSpace(candidate)) {
             v->VisitPointer(reinterpret_cast<Object**>(slot));
+          }
           candidate = GetNextCandidate(*slot);
           slot = GetNextCandidateSlot(*slot);
+        }
+      }
       MarkCompactCollector::~MarkCompactCollector() {
         if (code_flusher_ != NULL) {
           delete code_flusher_;
           code_flusher_ = NULL;
+        }
+      }
       static inline HeapObject* ShortCircuitConsString(Object** p) {
         // Optimization: If the heap object pointed to by p is a non-internalized
         // cons string whose right substring is HEAP->empty_string, update
         // it in place to its left substring.  Return the updated value.
         //
         // Here we assume that if we change *p, we replace it with a heap object
         // (i.e., the left substring of a cons string is always a heap object).
         //
         // The check performed is:
         //   object->IsConsString() && !object->IsInternalizedString() &&
         //   (ConsString::cast(object)->second() == HEAP->empty_string())
         // except the maps for the object and its possible substrings might be
         // marked.
         HeapObject* object = HeapObject::cast(*p);
         if (!FLAG_clever_optimizations) return object;
         Map* map = object->map();
         InstanceType type = map->instance_type();
         if ((type & kShortcutTypeMask) != kShortcutTypeTag) return object;
         Object* second = reinterpret_cast<ConsString*>(object)->second();
         Heap* heap = map->GetHeap();
         if (second != heap->empty_string()) {
           return object;
+        }
         // Since we don't have the object's start, it is impossible to update the
         // page dirty marks. Therefore, we only replace the string with its left
         // substring when page dirty marks do not change.
         Object* first = reinterpret_cast<ConsString*>(object)->first();
         if (!heap->InNewSpace(object) && heap->InNewSpace(first)) return object;
         *p = first;
         return HeapObject::cast(first);
+      }
       class MarkCompactMarkingVisitor
           : public StaticMarkingVisitor<MarkCompactMarkingVisitor> {
        public:
         static void ObjectStatsVisitBase(StaticVisitorBase::VisitorId id,
                                          Map* map, HeapObject* obj);
         static void ObjectStatsCountFixedArray(
             FixedArrayBase* fixed_array,
             FixedArraySubInstanceType fast_type,
             FixedArraySubInstanceType dictionary_type);
         template<MarkCompactMarkingVisitor::VisitorId id>
         class ObjectStatsTracker {
          public:
           static inline void Visit(Map* map, HeapObject* obj);
         };
         static void Initialize();
         INLINE(static void VisitPointer(Heap* heap, Object** p)) {
           MarkObjectByPointer(heap->mark_compact_collector(), p, p);
+        }
         INLINE(static void VisitPointers(Heap* heap, Object** start, Object** end)) {
           // Mark all objects pointed to in [start, end).
           const int kMinRangeForMarkingRecursion = 64;
           if (end - start >= kMinRangeForMarkingRecursion) {
             if (VisitUnmarkedObjects(heap, start, end)) return;
             // We are close to a stack overflow, so just mark the objects.
+          }
           MarkCompactCollector* collector = heap->mark_compact_collector();
           for (Object** p = start; p < end; p++) {
             MarkObjectByPointer(collector, start, p);
+          }
+        }
         // Marks the object black and pushes it on the marking stack.
         INLINE(static void MarkObject(Heap* heap, HeapObject* object)) {
           MarkBit mark = Marking::MarkBitFrom(object);
           heap->mark_compact_collector()->MarkObject(object, mark);
+        }
         // Marks the object black without pushing it on the marking stack.
         // Returns true if object needed marking and false otherwise.
         INLINE(static bool MarkObjectWithoutPush(Heap* heap, HeapObject* object)) {
           MarkBit mark_bit = Marking::MarkBitFrom(object);
           if (!mark_bit.Get()) {
             heap->mark_compact_collector()->SetMark(object, mark_bit);
             return true;
+          }
           return false;
+        }
         // Mark object pointed to by p.
         INLINE(static void MarkObjectByPointer(MarkCompactCollector* collector,
                                                Object** anchor_slot,
                                                Object** p)) {
           if (!(*p)->IsHeapObject()) return;
           HeapObject* object = ShortCircuitConsString(p);
           collector->RecordSlot(anchor_slot, p, object);
           MarkBit mark = Marking::MarkBitFrom(object);
           collector->MarkObject(object, mark);
+        }
         // Visit an unmarked object.
         INLINE(static void VisitUnmarkedObject(MarkCompactCollector* collector,
                                                HeapObject* obj)) {
       #ifdef DEBUG
           ASSERT(collector->heap()->Contains(obj));
           ASSERT(!collector->heap()->mark_compact_collector()->IsMarked(obj));
       #endif
           Map* map = obj->map();
           Heap* heap = obj->GetHeap();
           MarkBit mark = Marking::MarkBitFrom(obj);
           heap->mark_compact_collector()->SetMark(obj, mark);
           // Mark the map pointer and the body.
           MarkBit map_mark = Marking::MarkBitFrom(map);
           heap->mark_compact_collector()->MarkObject(map, map_mark);
           IterateBody(map, obj);
+        }
         // Visit all unmarked objects pointed to by [start, end).
         // Returns false if the operation fails (lack of stack space).
         INLINE(static bool VisitUnmarkedObjects(Heap* heap,
                                                 Object** start,
                                                 Object** end)) {
           // Return false is we are close to the stack limit.
           StackLimitCheck check(heap->isolate());
           if (check.HasOverflowed()) return false;
           MarkCompactCollector* collector = heap->mark_compact_collector();
           // Visit the unmarked objects.
           for (Object** p = start; p < end; p++) {
             Object* o = *p;
             if (!o->IsHeapObject()) continue;
             collector->RecordSlot(start, p, o);
             HeapObject* obj = HeapObject::cast(o);
             MarkBit mark = Marking::MarkBitFrom(obj);
             if (mark.Get()) continue;
             VisitUnmarkedObject(collector, obj);
+          }
           return true;
+        }
         INLINE(static void BeforeVisitingSharedFunctionInfo(HeapObject* object)) {
           SharedFunctionInfo* shared = SharedFunctionInfo::cast(object);
           shared->BeforeVisitingPointers();
+        }
         static void VisitWeakCollection(Map* map, HeapObject* object) {
           MarkCompactCollector* collector = map->GetHeap()->mark_compact_collector();
           JSWeakCollection* weak_collection =
               reinterpret_cast<JSWeakCollection*>(object);
           // Enqueue weak map in linked list of encountered weak maps.
           if (weak_collection->next() == Smi::FromInt(0)) {
             weak_collection->set_next(collector->encountered_weak_collections());
             collector->set_encountered_weak_collections(weak_collection);
+          }
           // Skip visiting the backing hash table containing the mappings.
           int object_size = JSWeakCollection::BodyDescriptor::SizeOf(map, object);
           BodyVisitorBase<MarkCompactMarkingVisitor>::IteratePointers(
               map->GetHeap(),
               object,
               JSWeakCollection::BodyDescriptor::kStartOffset,
               JSWeakCollection::kTableOffset);
           BodyVisitorBase<MarkCompactMarkingVisitor>::IteratePointers(
               map->GetHeap(),
               object,
               JSWeakCollection::kTableOffset + kPointerSize,
               object_size);
           // Mark the backing hash table without pushing it on the marking stack.
           Object* table_object = weak_collection->table();
           if (!table_object->IsHashTable()) return;
           WeakHashTable* table = WeakHashTable::cast(table_object);
           Object** table_slot =
               HeapObject::RawField(weak_collection, JSWeakCollection::kTableOffset);
           MarkBit table_mark = Marking::MarkBitFrom(table);
           collector->RecordSlot(table_slot, table_slot, table);
           if (!table_mark.Get()) collector->SetMark(table, table_mark);
           // Recording the map slot can be skipped, because maps are not compacted.
           collector->MarkObject(table->map(), Marking::MarkBitFrom(table->map()));
           ASSERT(MarkCompactCollector::IsMarked(table->map()));
+        }
        private:
         template<int id>
         static inline void TrackObjectStatsAndVisit(Map* map, HeapObject* obj);
         // Code flushing support.
         static const int kRegExpCodeThreshold = 5;
         static void UpdateRegExpCodeAgeAndFlush(Heap* heap,
                                                 JSRegExp* re,
                                                 bool is_ascii) {
           // Make sure that the fixed array is in fact initialized on the RegExp.
           // We could potentially trigger a GC when initializing the RegExp.
           if (HeapObject::cast(re->data())->map()->instance_type() !=
                   FIXED_ARRAY_TYPE) return;
           // Make sure this is a RegExp that actually contains code.
           if (re->TypeTag() != JSRegExp::IRREGEXP) return;
           Object* code = re->DataAt(JSRegExp::code_index(is_ascii));
           if (!code->IsSmi() &&
               HeapObject::cast(code)->map()->instance_type() == CODE_TYPE) {
             // Save a copy that can be reinstated if we need the code again.
             re->SetDataAt(JSRegExp::saved_code_index(is_ascii), code);
             // Saving a copy might create a pointer into compaction candidate
             // that was not observed by marker.  This might happen if JSRegExp data
             // was marked through the compilation cache before marker reached JSRegExp
             // object.
             FixedArray* data = FixedArray::cast(re->data());
             Object** slot = data->data_start() + JSRegExp::saved_code_index(is_ascii);
             heap->mark_compact_collector()->
                 RecordSlot(slot, slot, code);
             // Set a number in the 0-255 range to guarantee no smi overflow.
             re->SetDataAt(JSRegExp::code_index(is_ascii),
                           Smi::FromInt(heap->sweep_generation() & 0xff));
           } else if (code->IsSmi()) {
             int value = Smi::cast(code)->value();
             // The regexp has not been compiled yet or there was a compilation error.
             if (value == JSRegExp::kUninitializedValue ||
                 value == JSRegExp::kCompilationErrorValue) {
               return;
+            }
             // Check if we should flush now.
             if (value == ((heap->sweep_generation() - kRegExpCodeThreshold) & 0xff)) {
               re->SetDataAt(JSRegExp::code_index(is_ascii),
                             Smi::FromInt(JSRegExp::kUninitializedValue));
               re->SetDataAt(JSRegExp::saved_code_index(is_ascii),
                             Smi::FromInt(JSRegExp::kUninitializedValue));
+            }
+          }
+        }
         // Works by setting the current sweep_generation (as a smi) in the
         // code object place in the data array of the RegExp and keeps a copy
         // around that can be reinstated if we reuse the RegExp before flushing.
         // If we did not use the code for kRegExpCodeThreshold mark sweep GCs
         // we flush the code.
         static void VisitRegExpAndFlushCode(Map* map, HeapObject* object) {
           Heap* heap = map->GetHeap();
           MarkCompactCollector* collector = heap->mark_compact_collector();
           if (!collector->is_code_flushing_enabled()) {
             VisitJSRegExp(map, object);
             return;
+          }
           JSRegExp* re = reinterpret_cast<JSRegExp*>(object);
           // Flush code or set age on both ASCII and two byte code.
           UpdateRegExpCodeAgeAndFlush(heap, re, true);
           UpdateRegExpCodeAgeAndFlush(heap, re, false);
           // Visit the fields of the RegExp, including the updated FixedArray.
           VisitJSRegExp(map, object);
+        }
         static VisitorDispatchTable<Callback> non_count_table_;
       };
       void MarkCompactMarkingVisitor::ObjectStatsCountFixedArray(
           FixedArrayBase* fixed_array,
           FixedArraySubInstanceType fast_type,
           FixedArraySubInstanceType dictionary_type) {
         Heap* heap = fixed_array->map()->GetHeap();
         if (fixed_array->map() != heap->fixed_cow_array_map() &&
             fixed_array->map() != heap->fixed_double_array_map() &&
             fixed_array != heap->empty_fixed_array()) {
           if (fixed_array->IsDictionary()) {
             heap->RecordFixedArraySubTypeStats(dictionary_type,
                                                fixed_array->Size());
           } else {
             heap->RecordFixedArraySubTypeStats(fast_type,
                                                fixed_array->Size());
+          }
+        }
+      }
       void MarkCompactMarkingVisitor::ObjectStatsVisitBase(
           MarkCompactMarkingVisitor::VisitorId id, Map* map, HeapObject* obj) {
         Heap* heap = map->GetHeap();
         int object_size = obj->Size();
         heap->RecordObjectStats(map->instance_type(), object_size);
         non_count_table_.GetVisitorById(id)(map, obj);
         if (obj->IsJSObject()) {
           JSObject* object = JSObject::cast(obj);
           ObjectStatsCountFixedArray(object->elements(),
                                      DICTIONARY_ELEMENTS_SUB_TYPE,
                                      FAST_ELEMENTS_SUB_TYPE);
           ObjectStatsCountFixedArray(object->properties(),
                                      DICTIONARY_PROPERTIES_SUB_TYPE,
                                      FAST_PROPERTIES_SUB_TYPE);
+        }
+      }
       template<MarkCompactMarkingVisitor::VisitorId id>
       void MarkCompactMarkingVisitor::ObjectStatsTracker<id>::Visit(
           Map* map, HeapObject* obj) {
         ObjectStatsVisitBase(id, map, obj);
+      }
       template<>
       class MarkCompactMarkingVisitor::ObjectStatsTracker<
           MarkCompactMarkingVisitor::kVisitMap> {
        public:
         static inline void Visit(Map* map, HeapObject* obj) {
           Heap* heap = map->GetHeap();
           Map* map_obj = Map::cast(obj);
           ASSERT(map->instance_type() == MAP_TYPE);
           DescriptorArray* array = map_obj->instance_descriptors();
           if (map_obj->owns_descriptors() &&
               array != heap->empty_descriptor_array()) {
             int fixed_array_size = array->Size();
             heap->RecordFixedArraySubTypeStats(DESCRIPTOR_ARRAY_SUB_TYPE,
                                                fixed_array_size);
+          }
           if (map_obj->HasTransitionArray()) {
             int fixed_array_size = map_obj->transitions()->Size();
             heap->RecordFixedArraySubTypeStats(TRANSITION_ARRAY_SUB_TYPE,
                                                fixed_array_size);
+          }
           if (map_obj->has_code_cache()) {
             CodeCache* cache = CodeCache::cast(map_obj->code_cache());
             heap->RecordFixedArraySubTypeStats(MAP_CODE_CACHE_SUB_TYPE,
                                                cache->default_cache()->Size());
             if (!cache->normal_type_cache()->IsUndefined()) {
               heap->RecordFixedArraySubTypeStats(
                   MAP_CODE_CACHE_SUB_TYPE,
                   FixedArray::cast(cache->normal_type_cache())->Size());
+            }
+          }
           ObjectStatsVisitBase(kVisitMap, map, obj);
+        }
       };
       template<>
       class MarkCompactMarkingVisitor::ObjectStatsTracker<
           MarkCompactMarkingVisitor::kVisitCode> {
        public:
         static inline void Visit(Map* map, HeapObject* obj) {
           Heap* heap = map->GetHeap();
           int object_size = obj->Size();
           ASSERT(map->instance_type() == CODE_TYPE);
           Code* code_obj = Code::cast(obj);
           heap->RecordCodeSubTypeStats(code_obj->kind(), code_obj->GetAge(),
                                        object_size);
           ObjectStatsVisitBase(kVisitCode, map, obj);
+        }
       };
       template<>
       class MarkCompactMarkingVisitor::ObjectStatsTracker<
           MarkCompactMarkingVisitor::kVisitSharedFunctionInfo> {
        public:
         static inline void Visit(Map* map, HeapObject* obj) {
           Heap* heap = map->GetHeap();
           SharedFunctionInfo* sfi = SharedFunctionInfo::cast(obj);
           if (sfi->scope_info() != heap->empty_fixed_array()) {
             heap->RecordFixedArraySubTypeStats(
                 SCOPE_INFO_SUB_TYPE,
                 FixedArray::cast(sfi->scope_info())->Size());
+          }
           ObjectStatsVisitBase(kVisitSharedFunctionInfo, map, obj);
+        }
       };
       template<>
       class MarkCompactMarkingVisitor::ObjectStatsTracker<
           MarkCompactMarkingVisitor::kVisitFixedArray> {
        public:
         static inline void Visit(Map* map, HeapObject* obj) {
           Heap* heap = map->GetHeap();
           FixedArray* fixed_array = FixedArray::cast(obj);
           if (fixed_array == heap->string_table()) {
             heap->RecordFixedArraySubTypeStats(
                 STRING_TABLE_SUB_TYPE,
                 fixed_array->Size());
+          }
           ObjectStatsVisitBase(kVisitFixedArray, map, obj);
+        }
       };
       void MarkCompactMarkingVisitor::Initialize() {
         StaticMarkingVisitor<MarkCompactMarkingVisitor>::Initialize();
         table_.Register(kVisitJSRegExp,
                         &VisitRegExpAndFlushCode);
         if (FLAG_track_gc_object_stats) {
           // Copy the visitor table to make call-through possible.
           non_count_table_.CopyFrom(&table_);
       #define VISITOR_ID_COUNT_FUNCTION(id)                                   \
           table_.Register(kVisit##id, ObjectStatsTracker<kVisit##id>::Visit);
           VISITOR_ID_LIST(VISITOR_ID_COUNT_FUNCTION)
       #undef VISITOR_ID_COUNT_FUNCTION
+        }
+      }
       VisitorDispatchTable<MarkCompactMarkingVisitor::Callback>
           MarkCompactMarkingVisitor::non_count_table_;
       class CodeMarkingVisitor : public ThreadVisitor {
        public:
         explicit CodeMarkingVisitor(MarkCompactCollector* collector)
             : collector_(collector) {}
         void VisitThread(Isolate* isolate, ThreadLocalTop* top) {
           collector_->PrepareThreadForCodeFlushing(isolate, top);
+        }
        private:
         MarkCompactCollector* collector_;
       };
       class SharedFunctionInfoMarkingVisitor : public ObjectVisitor {
        public:
         explicit SharedFunctionInfoMarkingVisitor(MarkCompactCollector* collector)
             : collector_(collector) {}
         void VisitPointers(Object** start, Object** end) {
           for (Object** p = start; p < end; p++) VisitPointer(p);
+        }
         void VisitPointer(Object** slot) {
           Object* obj = *slot;
           if (obj->IsSharedFunctionInfo()) {
             SharedFunctionInfo* shared = reinterpret_cast<SharedFunctionInfo*>(obj);
             MarkBit shared_mark = Marking::MarkBitFrom(shared);
             MarkBit code_mark = Marking::MarkBitFrom(shared->code());
             collector_->MarkObject(shared->code(), code_mark);
             collector_->MarkObject(shared, shared_mark);
+          }
+        }
        private:
         MarkCompactCollector* collector_;
       };
       void MarkCompactCollector::PrepareThreadForCodeFlushing(Isolate* isolate,
                                                               ThreadLocalTop* top) {
         for (StackFrameIterator it(isolate, top); !it.done(); it.Advance()) {
           // Note: for the frame that has a pending lazy deoptimization
           // StackFrame::unchecked_code will return a non-optimized code object for
           // the outermost function and StackFrame::LookupCode will return
           // actual optimized code object.
           StackFrame* frame = it.frame();
           Code* code = frame->unchecked_code();
           MarkBit code_mark = Marking::MarkBitFrom(code);
           MarkObject(code, code_mark);
           if (frame->is_optimized()) {
             MarkCompactMarkingVisitor::MarkInlinedFunctionsCode(heap(),
                                                                 frame->LookupCode());
+          }
+        }
+      }
       void MarkCompactCollector::PrepareForCodeFlushing() {
         // Enable code flushing for non-incremental cycles.
         if (FLAG_flush_code && !FLAG_flush_code_incrementally) {
           EnableCodeFlushing(!was_marked_incrementally_);
+        }
         // If code flushing is disabled, there is no need to prepare for it.
         if (!is_code_flushing_enabled()) return;
         // Ensure that empty descriptor array is marked. Method MarkDescriptorArray
         // relies on it being marked before any other descriptor array.
         HeapObject* descriptor_array = heap()->empty_descriptor_array();
         MarkBit descriptor_array_mark = Marking::MarkBitFrom(descriptor_array);
         MarkObject(descriptor_array, descriptor_array_mark);
         // Make sure we are not referencing the code from the stack.
         ASSERT(this == heap()->mark_compact_collector());
         PrepareThreadForCodeFlushing(heap()->isolate(),
                                      heap()->isolate()->thread_local_top());
         // Iterate the archived stacks in all threads to check if
         // the code is referenced.
         CodeMarkingVisitor code_marking_visitor(this);
         heap()->isolate()->thread_manager()->IterateArchivedThreads(
             &code_marking_visitor);
         SharedFunctionInfoMarkingVisitor visitor(this);
         heap()->isolate()->compilation_cache()->IterateFunctions(&visitor);
         heap()->isolate()->handle_scope_implementer()->Iterate(&visitor);
         ProcessMarkingDeque();
+      }
       // Visitor class for marking heap roots.
       class RootMarkingVisitor : public ObjectVisitor {
        public:
         explicit RootMarkingVisitor(Heap* heap)
           : collector_(heap->mark_compact_collector()) { }
         void VisitPointer(Object** p) {
           MarkObjectByPointer(p);
+        }
         void VisitPointers(Object** start, Object** end) {
           for (Object** p = start; p < end; p++) MarkObjectByPointer(p);
+        }
        private:
         void MarkObjectByPointer(Object** p) {
           if (!(*p)->IsHeapObject()) return;
           // Replace flat cons strings in place.
           HeapObject* object = ShortCircuitConsString(p);
           MarkBit mark_bit = Marking::MarkBitFrom(object);
           if (mark_bit.Get()) return;
           Map* map = object->map();
           // Mark the object.
           collector_->SetMark(object, mark_bit);
           // Mark the map pointer and body, and push them on the marking stack.
           MarkBit map_mark = Marking::MarkBitFrom(map);
           collector_->MarkObject(map, map_mark);
           MarkCompactMarkingVisitor::IterateBody(map, object);
           // Mark all the objects reachable from the map and body.  May leave
           // overflowed objects in the heap.
           collector_->EmptyMarkingDeque();
+        }
         MarkCompactCollector* collector_;
       };
       // Helper class for pruning the string table.
       class StringTableCleaner : public ObjectVisitor {
        public:
         explicit StringTableCleaner(Heap* heap)
           : heap_(heap), pointers_removed_(0) { }
         virtual void VisitPointers(Object** start, Object** end) {
           // Visit all HeapObject pointers in [start, end).
           for (Object** p = start; p < end; p++) {
             Object* o = *p;
             if (o->IsHeapObject() &&
                 !Marking::MarkBitFrom(HeapObject::cast(o)).Get()) {
               // Check if the internalized string being pruned is external. We need to
               // delete the associated external data as this string is going away.
               // Since no objects have yet been moved we can safely access the map of
               // the object.
               if (o->IsExternalString()) {
                 heap_->FinalizeExternalString(String::cast(*p));
+              }
               // Set the entry to the_hole_value (as deleted).
               *p = heap_->the_hole_value();
               pointers_removed_++;
+            }
+          }
+        }
         int PointersRemoved() {
           return pointers_removed_;
+        }
        private:
         Heap* heap_;
         int pointers_removed_;
       };
       // Implementation of WeakObjectRetainer for mark compact GCs. All marked objects
       // are retained.
       class MarkCompactWeakObjectRetainer : public WeakObjectRetainer {
        public:
         virtual Object* RetainAs(Object* object) {
           if (Marking::MarkBitFrom(HeapObject::cast(object)).Get()) {
             return object;
           } else {
             return NULL;
+          }
+        }
       };
       // Fill the marking stack with overflowed objects returned by the given
       // iterator.  Stop when the marking stack is filled or the end of the space
       // is reached, whichever comes first.
       template<class T>
       static void DiscoverGreyObjectsWithIterator(Heap* heap,
                                                   MarkingDeque* marking_deque,
                                                   T* it) {
         // The caller should ensure that the marking stack is initially not full,
         // so that we don't waste effort pointlessly scanning for objects.
         ASSERT(!marking_deque->IsFull());
         Map* filler_map = heap->one_pointer_filler_map();
         for (HeapObject* object = it->Next();
              object != NULL;
              object = it->Next()) {
           MarkBit markbit = Marking::MarkBitFrom(object);
           if ((object->map() != filler_map) && Marking::IsGrey(markbit)) {
             Marking::GreyToBlack(markbit);
             MemoryChunk::IncrementLiveBytesFromGC(object->address(), object->Size());
             marking_deque->PushBlack(object);
             if (marking_deque->IsFull()) return;
+          }
+        }
+      }
       static inline int MarkWordToObjectStarts(uint32_t mark_bits, int* starts);
       static void DiscoverGreyObjectsOnPage(MarkingDeque* marking_deque,
                                             MemoryChunk* p) {
         ASSERT(!marking_deque->IsFull());
         ASSERT(strcmp(Marking::kWhiteBitPattern, "00") == 0);
         ASSERT(strcmp(Marking::kBlackBitPattern, "10") == 0);
         ASSERT(strcmp(Marking::kGreyBitPattern, "11") == 0);
         ASSERT(strcmp(Marking::kImpossibleBitPattern, "01") == 0);
         for (MarkBitCellIterator it(p); !it.Done(); it.Advance()) {
           Address cell_base = it.CurrentCellBase();
           MarkBit::CellType* cell = it.CurrentCell();
           const MarkBit::CellType current_cell = *cell;
           if (current_cell == 0) continue;
           MarkBit::CellType grey_objects;
           if (it.HasNext()) {
             const MarkBit::CellType next_cell = *(cell+1);
             grey_objects = current_cell &
                 ((current_cell >> 1) | (next_cell << (Bitmap::kBitsPerCell - 1)));
           } else {
             grey_objects = current_cell & (current_cell >> 1);
+          }
           int offset = 0;
           while (grey_objects != 0) {
             int trailing_zeros = CompilerIntrinsics::CountTrailingZeros(grey_objects);
             grey_objects >>= trailing_zeros;
             offset += trailing_zeros;
             MarkBit markbit(cell, 1 << offset, false);
             ASSERT(Marking::IsGrey(markbit));
             Marking::GreyToBlack(markbit);
             Address addr = cell_base + offset * kPointerSize;
             HeapObject* object = HeapObject::FromAddress(addr);
             MemoryChunk::IncrementLiveBytesFromGC(object->address(), object->Size());
             marking_deque->PushBlack(object);
             if (marking_deque->IsFull()) return;
             offset += 2;
             grey_objects >>= 2;
+          }
           grey_objects >>= (Bitmap::kBitsPerCell - 1);
+        }
+      }
       int MarkCompactCollector::DiscoverAndPromoteBlackObjectsOnPage(
           NewSpace* new_space,
           NewSpacePage* p) {
         ASSERT(strcmp(Marking::kWhiteBitPattern, "00") == 0);
         ASSERT(strcmp(Marking::kBlackBitPattern, "10") == 0);
         ASSERT(strcmp(Marking::kGreyBitPattern, "11") == 0);
         ASSERT(strcmp(Marking::kImpossibleBitPattern, "01") == 0);
         MarkBit::CellType* cells = p->markbits()->cells();
         int survivors_size = 0;
         for (MarkBitCellIterator it(p); !it.Done(); it.Advance()) {
           Address cell_base = it.CurrentCellBase();
           MarkBit::CellType* cell = it.CurrentCell();
           MarkBit::CellType current_cell = *cell;
           if (current_cell == 0) continue;
           int offset = 0;
           while (current_cell != 0) {
             int trailing_zeros = CompilerIntrinsics::CountTrailingZeros(current_cell);
             current_cell >>= trailing_zeros;
             offset += trailing_zeros;
             Address address = cell_base + offset * kPointerSize;
             HeapObject* object = HeapObject::FromAddress(address);
             int size = object->Size();
             survivors_size += size;
             if (FLAG_trace_track_allocation_sites && object->IsJSObject()) {
               if (AllocationMemento::FindForJSObject(JSObject::cast(object), true)
                   != NULL) {
                 heap()->allocation_mementos_found_++;
+              }
+            }
             offset++;
             current_cell >>= 1;
             // Aggressively promote young survivors to the old space.
             if (TryPromoteObject(object, size)) {
               continue;
+            }
             // Promotion failed. Just migrate object to another semispace.
             MaybeObject* allocation = new_space->AllocateRaw(size);
             if (allocation->IsFailure()) {
               if (!new_space->AddFreshPage()) {
                 // Shouldn't happen. We are sweeping linearly, and to-space
                 // has the same number of pages as from-space, so there is
                 // always room.
                 UNREACHABLE();
+              }
               allocation = new_space->AllocateRaw(size);
               ASSERT(!allocation->IsFailure());
+            }
             Object* target = allocation->ToObjectUnchecked();
             MigrateObject(HeapObject::cast(target)->address(),
                           object->address(),
                           size,
                           NEW_SPACE);
+          }
           *cells = 0;
+        }
         return survivors_size;
+      }
       static void DiscoverGreyObjectsInSpace(Heap* heap,
                                              MarkingDeque* marking_deque,
                                              PagedSpace* space) {
         if (!space->was_swept_conservatively()) {
           HeapObjectIterator it(space);
           DiscoverGreyObjectsWithIterator(heap, marking_deque, &it);
         } else {
           PageIterator it(space);
           while (it.has_next()) {
             Page* p = it.next();
             DiscoverGreyObjectsOnPage(marking_deque, p);
             if (marking_deque->IsFull()) return;
+          }
+        }
+      }
       static void DiscoverGreyObjectsInNewSpace(Heap* heap,
                                                 MarkingDeque* marking_deque) {
         NewSpace* space = heap->new_space();
         NewSpacePageIterator it(space->bottom(), space->top());
         while (it.has_next()) {
           NewSpacePage* page = it.next();
           DiscoverGreyObjectsOnPage(marking_deque, page);
           if (marking_deque->IsFull()) return;
+        }
+      }
       bool MarkCompactCollector::IsUnmarkedHeapObject(Object** p) {
         Object* o = *p;
         if (!o->IsHeapObject()) return false;
         HeapObject* heap_object = HeapObject::cast(o);
         MarkBit mark = Marking::MarkBitFrom(heap_object);
         return !mark.Get();
+      }
       bool MarkCompactCollector::IsUnmarkedHeapObjectWithHeap(Heap* heap,
                                                               Object** p) {
         Object* o = *p;
         ASSERT(o->IsHeapObject());
         HeapObject* heap_object = HeapObject::cast(o);
         MarkBit mark = Marking::MarkBitFrom(heap_object);
         return !mark.Get();
+      }
       void MarkCompactCollector::MarkStringTable(RootMarkingVisitor* visitor) {
         StringTable* string_table = heap()->string_table();
         // Mark the string table itself.
         MarkBit string_table_mark = Marking::MarkBitFrom(string_table);
         SetMark(string_table, string_table_mark);
         // Explicitly mark the prefix.
         string_table->IteratePrefix(visitor);
         ProcessMarkingDeque();
+      }
       void MarkCompactCollector::MarkRoots(RootMarkingVisitor* visitor) {
         // Mark the heap roots including global variables, stack variables,
         // etc., and all objects reachable from them.
         heap()->IterateStrongRoots(visitor, VISIT_ONLY_STRONG);
         // Handle the string table specially.
         MarkStringTable(visitor);
         MarkWeakObjectToCodeTable();
         // There may be overflowed objects in the heap.  Visit them now.
         while (marking_deque_.overflowed()) {
           RefillMarkingDeque();
           EmptyMarkingDeque();
+        }
+      }
       void MarkCompactCollector::MarkImplicitRefGroups() {
         List<ImplicitRefGroup*>* ref_groups =
             isolate()->global_handles()->implicit_ref_groups();
         int last = 0;
         for (int i = 0; i < ref_groups->length(); i++) {
           ImplicitRefGroup* entry = ref_groups->at(i);
           ASSERT(entry != NULL);
           if (!IsMarked(*entry->parent)) {
             (*ref_groups)[last++] = entry;
             continue;
+          }
           Object*** children = entry->children;
           // A parent object is marked, so mark all child heap objects.
           for (size_t j = 0; j < entry->length; ++j) {
             if ((*children[j])->IsHeapObject()) {
               HeapObject* child = HeapObject::cast(*children[j]);
               MarkBit mark = Marking::MarkBitFrom(child);
               MarkObject(child, mark);
+            }
+          }
           // Once the entire group has been marked, dispose it because it's
           // not needed anymore.
           delete entry;
+        }
         ref_groups->Rewind(last);
+      }
       void MarkCompactCollector::MarkWeakObjectToCodeTable() {
         HeapObject* weak_object_to_code_table =
             HeapObject::cast(heap()->weak_object_to_code_table());
         if (!IsMarked(weak_object_to_code_table)) {
           MarkBit mark = Marking::MarkBitFrom(weak_object_to_code_table);
           SetMark(weak_object_to_code_table, mark);
+        }
+      }
       // Mark all objects reachable from the objects on the marking stack.
       // Before: the marking stack contains zero or more heap object pointers.
       // After: the marking stack is empty, and all objects reachable from the
       // marking stack have been marked, or are overflowed in the heap.
       void MarkCompactCollector::EmptyMarkingDeque() {
         while (!marking_deque_.IsEmpty()) {
           HeapObject* object = marking_deque_.Pop();
           ASSERT(object->IsHeapObject());
           ASSERT(heap()->Contains(object));
           ASSERT(Marking::IsBlack(Marking::MarkBitFrom(object)));
           Map* map = object->map();
           MarkBit map_mark = Marking::MarkBitFrom(map);
           MarkObject(map, map_mark);
           MarkCompactMarkingVisitor::IterateBody(map, object);
+        }
+      }
       // Sweep the heap for overflowed objects, clear their overflow bits, and
       // push them on the marking stack.  Stop early if the marking stack fills
       // before sweeping completes.  If sweeping completes, there are no remaining
       // overflowed objects in the heap so the overflow flag on the markings stack
       // is cleared.
       void MarkCompactCollector::RefillMarkingDeque() {
         ASSERT(marking_deque_.overflowed());
         DiscoverGreyObjectsInNewSpace(heap(), &marking_deque_);
         if (marking_deque_.IsFull()) return;
         DiscoverGreyObjectsInSpace(heap(),
                                    &marking_deque_,
                                    heap()->old_pointer_space());
         if (marking_deque_.IsFull()) return;
         DiscoverGreyObjectsInSpace(heap(),
                                    &marking_deque_,
                                    heap()->old_data_space());
         if (marking_deque_.IsFull()) return;
         DiscoverGreyObjectsInSpace(heap(),
                                    &marking_deque_,
                                    heap()->code_space());
         if (marking_deque_.IsFull()) return;
         DiscoverGreyObjectsInSpace(heap(),
                                    &marking_deque_,
                                    heap()->map_space());
         if (marking_deque_.IsFull()) return;
         DiscoverGreyObjectsInSpace(heap(),
                                    &marking_deque_,
                                    heap()->cell_space());
         if (marking_deque_.IsFull()) return;
         DiscoverGreyObjectsInSpace(heap(),
                                    &marking_deque_,
                                    heap()->property_cell_space());
         if (marking_deque_.IsFull()) return;
         LargeObjectIterator lo_it(heap()->lo_space());
         DiscoverGreyObjectsWithIterator(heap(),
                                         &marking_deque_,
                                         &lo_it);
         if (marking_deque_.IsFull()) return;
         marking_deque_.ClearOverflowed();
+      }
       // Mark all objects reachable (transitively) from objects on the marking
       // stack.  Before: the marking stack contains zero or more heap object
       // pointers.  After: the marking stack is empty and there are no overflowed
       // objects in the heap.
       void MarkCompactCollector::ProcessMarkingDeque() {
         EmptyMarkingDeque();
         while (marking_deque_.overflowed()) {
           RefillMarkingDeque();
           EmptyMarkingDeque();
+        }
+      }
       // Mark all objects reachable (transitively) from objects on the marking
       // stack including references only considered in the atomic marking pause.
       void MarkCompactCollector::ProcessEphemeralMarking(ObjectVisitor* visitor) {
         bool work_to_do = true;
         ASSERT(marking_deque_.IsEmpty());
         while (work_to_do) {
           isolate()->global_handles()->IterateObjectGroups(
               visitor, &IsUnmarkedHeapObjectWithHeap);
           MarkImplicitRefGroups();
           ProcessWeakCollections();
           work_to_do = !marking_deque_.IsEmpty();
           ProcessMarkingDeque();
+        }
+      }
       void MarkCompactCollector::ProcessTopOptimizedFrame(ObjectVisitor* visitor) {
         for (StackFrameIterator it(isolate(), isolate()->thread_local_top());
              !it.done(); it.Advance()) {
           if (it.frame()->type() == StackFrame::JAVA_SCRIPT) {
             return;
+          }
           if (it.frame()->type() == StackFrame::OPTIMIZED) {
             Code* code = it.frame()->LookupCode();
             if (!code->CanDeoptAt(it.frame()->pc())) {
               code->CodeIterateBody(visitor);
+            }
             ProcessMarkingDeque();
             return;
+          }
+        }
+      }
       void MarkCompactCollector::MarkLiveObjects() {
         GCTracer::Scope gc_scope(tracer_, GCTracer::Scope::MC_MARK);
         // The recursive GC marker detects when it is nearing stack overflow,
         // and switches to a different marking system.  JS interrupts interfere
         // with the C stack limit check.
         PostponeInterruptsScope postpone(isolate());
         bool incremental_marking_overflowed = false;
         IncrementalMarking* incremental_marking = heap_->incremental_marking();
         if (was_marked_incrementally_) {
           // Finalize the incremental marking and check whether we had an overflow.
           // Both markers use grey color to mark overflowed objects so
           // non-incremental marker can deal with them as if overflow
           // occured during normal marking.
           // But incremental marker uses a separate marking deque
           // so we have to explicitly copy its overflow state.
           incremental_marking->Finalize();
           incremental_marking_overflowed =
               incremental_marking->marking_deque()->overflowed();
           incremental_marking->marking_deque()->ClearOverflowed();
         } else {
           // Abort any pending incremental activities e.g. incremental sweeping.
           incremental_marking->Abort();
+        }
       #ifdef DEBUG
         ASSERT(state_ == PREPARE_GC);
         state_ = MARK_LIVE_OBJECTS;
       #endif
         // The to space contains live objects, a page in from space is used as a
         // marking stack.
         Address marking_deque_start = heap()->new_space()->FromSpacePageLow();
         Address marking_deque_end = heap()->new_space()->FromSpacePageHigh();
         if (FLAG_force_marking_deque_overflows) {
           marking_deque_end = marking_deque_start + 64 * kPointerSize;
+        }
         marking_deque_.Initialize(marking_deque_start,
                                   marking_deque_end);
         ASSERT(!marking_deque_.overflowed());
         if (incremental_marking_overflowed) {
           // There are overflowed objects left in the heap after incremental marking.
           marking_deque_.SetOverflowed();
+        }
         PrepareForCodeFlushing();
         if (was_marked_incrementally_) {
           // There is no write barrier on cells so we have to scan them now at the end
           // of the incremental marking.
+          {
             HeapObjectIterator cell_iterator(heap()->cell_space());
             HeapObject* cell;
             while ((cell = cell_iterator.Next()) != NULL) {
               ASSERT(cell->IsCell());
               if (IsMarked(cell)) {
                 int offset = Cell::kValueOffset;
                 MarkCompactMarkingVisitor::VisitPointer(
                     heap(),
                     reinterpret_cast<Object**>(cell->address() + offset));
+              }
+            }
+          }
+          {
             HeapObjectIterator js_global_property_cell_iterator(
                 heap()->property_cell_space());
             HeapObject* cell;
             while ((cell = js_global_property_cell_iterator.Next()) != NULL) {
               ASSERT(cell->IsPropertyCell());
               if (IsMarked(cell)) {
                 MarkCompactMarkingVisitor::VisitPropertyCell(cell->map(), cell);
+              }
+            }
+          }
+        }
         RootMarkingVisitor root_visitor(heap());
         MarkRoots(&root_visitor);
         ProcessTopOptimizedFrame(&root_visitor);
         // The objects reachable from the roots are marked, yet unreachable
         // objects are unmarked.  Mark objects reachable due to host
         // application specific logic or through Harmony weak maps.
         ProcessEphemeralMarking(&root_visitor);
         // The objects reachable from the roots, weak maps or object groups
         // are marked, yet unreachable objects are unmarked.  Mark objects
         // reachable only from weak global handles.
         //
         // First we identify nonlive weak handles and mark them as pending
         // destruction.
         heap()->isolate()->global_handles()->IdentifyWeakHandles(
             &IsUnmarkedHeapObject);
         // Then we mark the objects and process the transitive closure.
         heap()->isolate()->global_handles()->IterateWeakRoots(&root_visitor);
         while (marking_deque_.overflowed()) {
           RefillMarkingDeque();
           EmptyMarkingDeque();
+        }
         // Repeat host application specific and Harmony weak maps marking to
         // mark unmarked objects reachable from the weak roots.
         ProcessEphemeralMarking(&root_visitor);
         AfterMarking();
+      }
       void MarkCompactCollector::AfterMarking() {
         // Object literal map caches reference strings (cache keys) and maps
         // (cache values). At this point still useful maps have already been
         // marked. Mark the keys for the alive values before we process the
         // string table.
         ProcessMapCaches();
         // Prune the string table removing all strings only pointed to by the
         // string table.  Cannot use string_table() here because the string
         // table is marked.
         StringTable* string_table = heap()->string_table();
         StringTableCleaner v(heap());
         string_table->IterateElements(&v);
         string_table->ElementsRemoved(v.PointersRemoved());
         heap()->external_string_table_.Iterate(&v);
         heap()->external_string_table_.CleanUp();
         // Process the weak references.
         MarkCompactWeakObjectRetainer mark_compact_object_retainer;
         heap()->ProcessWeakReferences(&mark_compact_object_retainer);
         // Remove object groups after marking phase.
         heap()->isolate()->global_handles()->RemoveObjectGroups();
         heap()->isolate()->global_handles()->RemoveImplicitRefGroups();
         // Flush code from collected candidates.
         if (is_code_flushing_enabled()) {
           code_flusher_->ProcessCandidates();
           // If incremental marker does not support code flushing, we need to
           // disable it before incremental marking steps for next cycle.
           if (FLAG_flush_code && !FLAG_flush_code_incrementally) {
             EnableCodeFlushing(false);
+          }
+        }
         if (!FLAG_watch_ic_patching) {
           // Clean up dead objects from the runtime profiler.
           heap()->isolate()->runtime_profiler()->RemoveDeadSamples();
+        }
         if (FLAG_track_gc_object_stats) {
           heap()->CheckpointObjectStats();
+        }
+      }
       void MarkCompactCollector::ProcessMapCaches() {
         Object* raw_context = heap()->native_contexts_list_;
         while (raw_context != heap()->undefined_value()) {
           Context* context = reinterpret_cast<Context*>(raw_context);
           if (IsMarked(context)) {
             HeapObject* raw_map_cache =
                 HeapObject::cast(context->get(Context::MAP_CACHE_INDEX));
             // A map cache may be reachable from the stack. In this case
             // it's already transitively marked and it's too late to clean
             // up its parts.
             if (!IsMarked(raw_map_cache) &&
                 raw_map_cache != heap()->undefined_value()) {
               MapCache* map_cache = reinterpret_cast<MapCache*>(raw_map_cache);
               int existing_elements = map_cache->NumberOfElements();
               int used_elements = 0;
               for (int i = MapCache::kElementsStartIndex;
                    i < map_cache->length();
                    i += MapCache::kEntrySize) {
                 Object* raw_key = map_cache->get(i);
                 if (raw_key == heap()->undefined_value() ||
                     raw_key == heap()->the_hole_value()) continue;
                 STATIC_ASSERT(MapCache::kEntrySize == 2);
                 Object* raw_map = map_cache->get(i + 1);
                 if (raw_map->IsHeapObject() && IsMarked(raw_map)) {
                   ++used_elements;
                 } else {
                   // Delete useless entries with unmarked maps.
                   ASSERT(raw_map->IsMap());
                   map_cache->set_the_hole(i);
                   map_cache->set_the_hole(i + 1);
+                }
+              }
               if (used_elements == 0) {
                 context->set(Context::MAP_CACHE_INDEX, heap()->undefined_value());
               } else {
                 // Note: we don't actually shrink the cache here to avoid
                 // extra complexity during GC. We rely on subsequent cache
                 // usages (EnsureCapacity) to do this.
                 map_cache->ElementsRemoved(existing_elements - used_elements);
                 MarkBit map_cache_markbit = Marking::MarkBitFrom(map_cache);
                 MarkObject(map_cache, map_cache_markbit);
+              }
+            }
+          }
           // Move to next element in the list.
           raw_context = context->get(Context::NEXT_CONTEXT_LINK);
+        }
         ProcessMarkingDeque();
+      }
       void MarkCompactCollector::ReattachInitialMaps() {
         HeapObjectIterator map_iterator(heap()->map_space());
         for (HeapObject* obj = map_iterator.Next();
              obj != NULL;
              obj = map_iterator.Next()) {
           Map* map = Map::cast(obj);
           STATIC_ASSERT(LAST_TYPE == LAST_JS_RECEIVER_TYPE);
           if (map->instance_type() < FIRST_JS_RECEIVER_TYPE) continue;
           if (map->attached_to_shared_function_info()) {
             JSFunction::cast(map->constructor())->shared()->AttachInitialMap(map);
+          }
+        }
+      }
       void MarkCompactCollector::ClearNonLiveReferences() {
         // Iterate over the map space, setting map transitions that go from
         // a marked map to an unmarked map to null transitions.  This action
         // is carried out only on maps of JSObjects and related subtypes.
         HeapObjectIterator map_iterator(heap()->map_space());
         for (HeapObject* obj = map_iterator.Next();
              obj != NULL;
              obj = map_iterator.Next()) {
           Map* map = Map::cast(obj);
           if (!map->CanTransition()) continue;
           MarkBit map_mark = Marking::MarkBitFrom(map);
           if (map_mark.Get() && map->attached_to_shared_function_info()) {
             // This map is used for inobject slack tracking and has been detached
             // from SharedFunctionInfo during the mark phase.
             // Since it survived the GC, reattach it now.
             JSFunction::cast(map->constructor())->shared()->AttachInitialMap(map);
+          }
           ClearNonLivePrototypeTransitions(map);
           ClearNonLiveMapTransitions(map, map_mark);
           if (map_mark.Get()) {
             ClearNonLiveDependentCode(map->dependent_code());
           } else {
             ClearAndDeoptimizeDependentCode(map->dependent_code());
             map->set_dependent_code(DependentCode::cast(heap()->empty_fixed_array()));
+          }
+        }
         // Iterate over property cell space, removing dependent code that is not
         // otherwise kept alive by strong references.
         HeapObjectIterator cell_iterator(heap_->property_cell_space());
         for (HeapObject* cell = cell_iterator.Next();
              cell != NULL;
              cell = cell_iterator.Next()) {
           if (IsMarked(cell)) {
             ClearNonLiveDependentCode(PropertyCell::cast(cell)->dependent_code());
+          }
+        }
         if (heap_->weak_object_to_code_table()->IsHashTable()) {
           WeakHashTable* table =
               WeakHashTable::cast(heap_->weak_object_to_code_table());
           uint32_t capacity = table->Capacity();
           for (uint32_t i = 0; i < capacity; i++) {
             uint32_t key_index = table->EntryToIndex(i);
             Object* key = table->get(key_index);
             if (!table->IsKey(key)) continue;
             uint32_t value_index = table->EntryToValueIndex(i);
             Object* value = table->get(value_index);
             if (IsMarked(key)) {
               if (!IsMarked(value)) {
                 HeapObject* obj = HeapObject::cast(value);
                 MarkBit mark = Marking::MarkBitFrom(obj);
                 SetMark(obj, mark);
+              }
               ClearNonLiveDependentCode(DependentCode::cast(value));
             } else {
               ClearAndDeoptimizeDependentCode(DependentCode::cast(value));
               table->set(key_index, heap_->the_hole_value());
               table->set(value_index, heap_->the_hole_value());
+            }
+          }
+        }
+      }
       void MarkCompactCollector::ClearNonLivePrototypeTransitions(Map* map) {
         int number_of_transitions = map->NumberOfProtoTransitions();
         FixedArray* prototype_transitions = map->GetPrototypeTransitions();
         int new_number_of_transitions = 0;
         const int header = Map::kProtoTransitionHeaderSize;
         const int proto_offset = header + Map::kProtoTransitionPrototypeOffset;
         const int map_offset = header + Map::kProtoTransitionMapOffset;
         const int step = Map::kProtoTransitionElementsPerEntry;
         for (int i = 0; i < number_of_transitions; i++) {
           Object* prototype = prototype_transitions->get(proto_offset + i * step);
           Object* cached_map = prototype_transitions->get(map_offset + i * step);
           if (IsMarked(prototype) && IsMarked(cached_map)) {
             int proto_index = proto_offset + new_number_of_transitions * step;
             int map_index = map_offset + new_number_of_transitions * step;
             if (new_number_of_transitions != i) {
               prototype_transitions->set(
                   proto_index,
                   prototype,
                   UPDATE_WRITE_BARRIER);
               prototype_transitions->set(
                   map_index,
                   cached_map,
                   SKIP_WRITE_BARRIER);
+            }
             Object** slot =
                 HeapObject::RawField(prototype_transitions,
                                      FixedArray::OffsetOfElementAt(proto_index));
             RecordSlot(slot, slot, prototype);
             new_number_of_transitions++;
+          }
+        }
         if (new_number_of_transitions != number_of_transitions) {
           map->SetNumberOfProtoTransitions(new_number_of_transitions);
+        }
         // Fill slots that became free with undefined value.
         for (int i = new_number_of_transitions * step;
              i < number_of_transitions * step;
              i++) {
           prototype_transitions->set_undefined(header + i);
+        }
+      }
       void MarkCompactCollector::ClearNonLiveMapTransitions(Map* map,
                                                             MarkBit map_mark) {
         Object* potential_parent = map->GetBackPointer();
         if (!potential_parent->IsMap()) return;
         Map* parent = Map::cast(potential_parent);
         // Follow back pointer, check whether we are dealing with a map transition
         // from a live map to a dead path and in case clear transitions of parent.
         bool current_is_alive = map_mark.Get();
         bool parent_is_alive = Marking::MarkBitFrom(parent).Get();
         if (!current_is_alive && parent_is_alive) {
           parent->ClearNonLiveTransitions(heap());
+        }
+      }
       void MarkCompactCollector::ClearAndDeoptimizeDependentCode(
           DependentCode* entries) {
         DisallowHeapAllocation no_allocation;
         DependentCode::GroupStartIndexes starts(entries);
         int number_of_entries = starts.number_of_entries();
         if (number_of_entries == 0) return;
         for (int i = 0; i < number_of_entries; i++) {
           // If the entry is compilation info then the map must be alive,
           // and ClearAndDeoptimizeDependentCode shouldn't be called.
           ASSERT(entries->is_code_at(i));
           Code* code = entries->code_at(i);
           if (IsMarked(code) && !code->marked_for_deoptimization()) {
             code->set_marked_for_deoptimization(true);
             have_code_to_deoptimize_ = true;
+          }
           entries->clear_at(i);
+        }
+      }
       void MarkCompactCollector::ClearNonLiveDependentCode(DependentCode* entries) {
         DisallowHeapAllocation no_allocation;
         DependentCode::GroupStartIndexes starts(entries);
         int number_of_entries = starts.number_of_entries();
         if (number_of_entries == 0) return;
         int new_number_of_entries = 0;
         // Go through all groups, remove dead codes and compact.
         for (int g = 0; g < DependentCode::kGroupCount; g++) {
           int group_number_of_entries = 0;
           for (int i = starts.at(g); i < starts.at(g + 1); i++) {
             Object* obj = entries->object_at(i);
             ASSERT(obj->IsCode() || IsMarked(obj));
             if (IsMarked(obj) &&
                 (!obj->IsCode() || !WillBeDeoptimized(Code::cast(obj)))) {
               if (new_number_of_entries + group_number_of_entries != i) {
                 entries->set_object_at(
                     new_number_of_entries + group_number_of_entries, obj);
+              }
               Object** slot = entries->slot_at(new_number_of_entries +
                                                group_number_of_entries);
               RecordSlot(slot, slot, obj);
               group_number_of_entries++;
+            }
+          }
           entries->set_number_of_entries(
               static_cast<DependentCode::DependencyGroup>(g),
               group_number_of_entries);
           new_number_of_entries += group_number_of_entries;
+        }
         for (int i = new_number_of_entries; i < number_of_entries; i++) {
           entries->clear_at(i);
+        }
+      }
       void MarkCompactCollector::ProcessWeakCollections() {
         GCTracer::Scope gc_scope(tracer_, GCTracer::Scope::MC_WEAKCOLLECTION_PROCESS);
         Object* weak_collection_obj = encountered_weak_collections();
         while (weak_collection_obj != Smi::FromInt(0)) {
           ASSERT(MarkCompactCollector::IsMarked(
               HeapObject::cast(weak_collection_obj)));
           JSWeakCollection* weak_collection =
               reinterpret_cast<JSWeakCollection*>(weak_collection_obj);
           ObjectHashTable* table = ObjectHashTable::cast(weak_collection->table());
           Object** anchor = reinterpret_cast<Object**>(table->address());
           for (int i = 0; i < table->Capacity(); i++) {
             if (MarkCompactCollector::IsMarked(HeapObject::cast(table->KeyAt(i)))) {
               Object** key_slot =
                   HeapObject::RawField(table, FixedArray::OffsetOfElementAt(
                       ObjectHashTable::EntryToIndex(i)));
               RecordSlot(anchor, key_slot, *key_slot);
               Object** value_slot =
                   HeapObject::RawField(table, FixedArray::OffsetOfElementAt(
                       ObjectHashTable::EntryToValueIndex(i)));
               MarkCompactMarkingVisitor::MarkObjectByPointer(
                   this, anchor, value_slot);
+            }
+          }
           weak_collection_obj = weak_collection->next();
+        }
+      }
       void MarkCompactCollector::ClearWeakCollections() {
         GCTracer::Scope gc_scope(tracer_, GCTracer::Scope::MC_WEAKCOLLECTION_CLEAR);
         Object* weak_collection_obj = encountered_weak_collections();
         while (weak_collection_obj != Smi::FromInt(0)) {
           ASSERT(MarkCompactCollector::IsMarked(
               HeapObject::cast(weak_collection_obj)));
           JSWeakCollection* weak_collection =
               reinterpret_cast<JSWeakCollection*>(weak_collection_obj);
           ObjectHashTable* table = ObjectHashTable::cast(weak_collection->table());
           for (int i = 0; i < table->Capacity(); i++) {
             if (!MarkCompactCollector::IsMarked(HeapObject::cast(table->KeyAt(i)))) {
               table->RemoveEntry(i);
+            }
+          }
           weak_collection_obj = weak_collection->next();
           weak_collection->set_next(Smi::FromInt(0));
+        }
         set_encountered_weak_collections(Smi::FromInt(0));
+      }
       // We scavange new space simultaneously with sweeping. This is done in two
       // passes.
       //
       // The first pass migrates all alive objects from one semispace to another or
       // promotes them to old space.  Forwarding address is written directly into
       // first word of object without any encoding.  If object is dead we write
       // NULL as a forwarding address.
       //
       // The second pass updates pointers to new space in all spaces.  It is possible
       // to encounter pointers to dead new space objects during traversal of pointers
       // to new space.  We should clear them to avoid encountering them during next
       // pointer iteration.  This is an issue if the store buffer overflows and we
       // have to scan the entire old space, including dead objects, looking for
       // pointers to new space.
       void MarkCompactCollector::MigrateObject(Address dst,
                                                Address src,
                                                int size,
                                                AllocationSpace dest) {
         HeapProfiler* heap_profiler = heap()->isolate()->heap_profiler();
         if (heap_profiler->is_profiling()) {
           heap_profiler->ObjectMoveEvent(src, dst, size);
+        }
         ASSERT(heap()->AllowedToBeMigrated(HeapObject::FromAddress(src), dest));
         ASSERT(dest != LO_SPACE && size <= Page::kMaxNonCodeHeapObjectSize);
         if (dest == OLD_POINTER_SPACE) {
           Address src_slot = src;
           Address dst_slot = dst;
           ASSERT(IsAligned(size, kPointerSize));
           for (int remaining = size / kPointerSize; remaining > 0; remaining--) {
             Object* value = Memory::Object_at(src_slot);
             Memory::Object_at(dst_slot) = value;
             if (heap_->InNewSpace(value)) {
               heap_->store_buffer()->Mark(dst_slot);
             } else if (value->IsHeapObject() && IsOnEvacuationCandidate(value)) {
               SlotsBuffer::AddTo(&slots_buffer_allocator_,
                                  &migration_slots_buffer_,
                                  reinterpret_cast<Object**>(dst_slot),
                                  SlotsBuffer::IGNORE_OVERFLOW);
+            }
             src_slot += kPointerSize;
             dst_slot += kPointerSize;
+          }
           if (compacting_ && HeapObject::FromAddress(dst)->IsJSFunction()) {
             Address code_entry_slot = dst + JSFunction::kCodeEntryOffset;
             Address code_entry = Memory::Address_at(code_entry_slot);
             if (Page::FromAddress(code_entry)->IsEvacuationCandidate()) {
               SlotsBuffer::AddTo(&slots_buffer_allocator_,
                                  &migration_slots_buffer_,
                                  SlotsBuffer::CODE_ENTRY_SLOT,
                                  code_entry_slot,
                                  SlotsBuffer::IGNORE_OVERFLOW);
+            }
+          }
         } else if (dest == CODE_SPACE) {
           PROFILE(isolate(), CodeMoveEvent(src, dst));
           heap()->MoveBlock(dst, src, size);
           SlotsBuffer::AddTo(&slots_buffer_allocator_,
                              &migration_slots_buffer_,
                              SlotsBuffer::RELOCATED_CODE_OBJECT,
                              dst,
                              SlotsBuffer::IGNORE_OVERFLOW);
           Code::cast(HeapObject::FromAddress(dst))->Relocate(dst - src);
         } else {
           ASSERT(dest == OLD_DATA_SPACE || dest == NEW_SPACE);
           heap()->MoveBlock(dst, src, size);
+        }
         Memory::Address_at(src) = dst;
+      }
       // Visitor for updating pointers from live objects in old spaces to new space.
       // It does not expect to encounter pointers to dead objects.
       class PointersUpdatingVisitor: public ObjectVisitor {
        public:
         explicit PointersUpdatingVisitor(Heap* heap) : heap_(heap) { }
         void VisitPointer(Object** p) {
           UpdatePointer(p);
+        }
         void VisitPointers(Object** start, Object** end) {
           for (Object** p = start; p < end; p++) UpdatePointer(p);
+        }
         void VisitEmbeddedPointer(RelocInfo* rinfo) {
           ASSERT(rinfo->rmode() == RelocInfo::EMBEDDED_OBJECT);
           Object* target = rinfo->target_object();
           Object* old_target = target;
           VisitPointer(&target);
           // Avoid unnecessary changes that might unnecessary flush the instruction
           // cache.
           if (target != old_target) {
             rinfo->set_target_object(target);
+          }
+        }
         void VisitCodeTarget(RelocInfo* rinfo) {
           ASSERT(RelocInfo::IsCodeTarget(rinfo->rmode()));
           Object* target = Code::GetCodeFromTargetAddress(rinfo->target_address());
           Object* old_target = target;
           VisitPointer(&target);
           if (target != old_target) {
             rinfo->set_target_address(Code::cast(target)->instruction_start());
+          }
+        }
         void VisitCodeAgeSequence(RelocInfo* rinfo) {
           ASSERT(RelocInfo::IsCodeAgeSequence(rinfo->rmode()));
           Object* stub = rinfo->code_age_stub();
           ASSERT(stub != NULL);
           VisitPointer(&stub);
           if (stub != rinfo->code_age_stub()) {
             rinfo->set_code_age_stub(Code::cast(stub));
+          }
+        }
         void VisitDebugTarget(RelocInfo* rinfo) {
           ASSERT((RelocInfo::IsJSReturn(rinfo->rmode()) &&
                   rinfo->IsPatchedReturnSequence()) ||
                  (RelocInfo::IsDebugBreakSlot(rinfo->rmode()) &&
                   rinfo->IsPatchedDebugBreakSlotSequence()));
           Object* target = Code::GetCodeFromTargetAddress(rinfo->call_address());
           VisitPointer(&target);
           rinfo->set_call_address(Code::cast(target)->instruction_start());
+        }
         static inline void UpdateSlot(Heap* heap, Object** slot) {
           Object* obj = *slot;
           if (!obj->IsHeapObject()) return;
           HeapObject* heap_obj = HeapObject::cast(obj);
           MapWord map_word = heap_obj->map_word();
           if (map_word.IsForwardingAddress()) {
             ASSERT(heap->InFromSpace(heap_obj) ||
                    MarkCompactCollector::IsOnEvacuationCandidate(heap_obj));
             HeapObject* target = map_word.ToForwardingAddress();
             *slot = target;
             ASSERT(!heap->InFromSpace(target) &&
                    !MarkCompactCollector::IsOnEvacuationCandidate(target));
+          }
+        }
        private:
         inline void UpdatePointer(Object** p) {
           UpdateSlot(heap_, p);
+        }
         Heap* heap_;
       };
       static void UpdatePointer(HeapObject** p, HeapObject* object) {
         ASSERT(*p == object);
         Address old_addr = object->address();
         Address new_addr = Memory::Address_at(old_addr);
         // The new space sweep will overwrite the map word of dead objects
         // with NULL. In this case we do not need to transfer this entry to
         // the store buffer which we are rebuilding.
         if (new_addr != NULL) {
           *p = HeapObject::FromAddress(new_addr);
         } else {
           // We have to zap this pointer, because the store buffer may overflow later,
           // and then we have to scan the entire heap and we don't want to find
           // spurious newspace pointers in the old space.
           // TODO(mstarzinger): This was changed to a sentinel value to track down
           // rare crashes, change it back to Smi::FromInt(0) later.
           *p = reinterpret_cast<HeapObject*>(Smi::FromInt(0x0f100d00 >> 1));  // flood
+        }
+      }
       static String* UpdateReferenceInExternalStringTableEntry(Heap* heap,
                                                                Object** p) {
         MapWord map_word = HeapObject::cast(*p)->map_word();
         if (map_word.IsForwardingAddress()) {
           return String::cast(map_word.ToForwardingAddress());
+        }
         return String::cast(*p);
+      }
       bool MarkCompactCollector::TryPromoteObject(HeapObject* object,
                                                   int object_size) {
         // TODO(hpayer): Replace that check with an assert.
         CHECK(object_size <= Page::kMaxNonCodeHeapObjectSize);
         OldSpace* target_space = heap()->TargetSpace(object);
         ASSERT(target_space == heap()->old_pointer_space() ||
                target_space == heap()->old_data_space());
         Object* result;
         MaybeObject* maybe_result = target_space->AllocateRaw(
             object_size,
             PagedSpace::MOVE_OBJECT);
         if (maybe_result->ToObject(&result)) {
           HeapObject* target = HeapObject::cast(result);
           MigrateObject(target->address(),
                         object->address(),
                         object_size,
                         target_space->identity());
           heap()->mark_compact_collector()->tracer()->
               increment_promoted_objects_size(object_size);
           return true;
+        }
         return false;
+      }
       void MarkCompactCollector::EvacuateNewSpace() {
         // There are soft limits in the allocation code, designed trigger a mark
         // sweep collection by failing allocations.  But since we are already in
         // a mark-sweep allocation, there is no sense in trying to trigger one.
         AlwaysAllocateScope scope;
         heap()->CheckNewSpaceExpansionCriteria();
         NewSpace* new_space = heap()->new_space();
         // Store allocation range before flipping semispaces.
         Address from_bottom = new_space->bottom();
         Address from_top = new_space->top();
         // Flip the semispaces.  After flipping, to space is empty, from space has
         // live objects.
         new_space->Flip();
         new_space->ResetAllocationInfo();
         int survivors_size = 0;
         // First pass: traverse all objects in inactive semispace, remove marks,
         // migrate live objects and write forwarding addresses.  This stage puts
         // new entries in the store buffer and may cause some pages to be marked
         // scan-on-scavenge.
         NewSpacePageIterator it(from_bottom, from_top);
         while (it.has_next()) {
           NewSpacePage* p = it.next();
           survivors_size += DiscoverAndPromoteBlackObjectsOnPage(new_space, p);
+        }
         heap_->IncrementYoungSurvivorsCounter(survivors_size);
         new_space->set_age_mark(new_space->top());
+      }
       void MarkCompactCollector::EvacuateLiveObjectsFromPage(Page* p) {
         AlwaysAllocateScope always_allocate;
         PagedSpace* space = static_cast<PagedSpace*>(p->owner());
         ASSERT(p->IsEvacuationCandidate() && !p->WasSwept());
         p->MarkSweptPrecisely();
         int offsets[16];
         for (MarkBitCellIterator it(p); !it.Done(); it.Advance()) {
           Address cell_base = it.CurrentCellBase();
           MarkBit::CellType* cell = it.CurrentCell();
           if (*cell == 0) continue;
           int live_objects = MarkWordToObjectStarts(*cell, offsets);
           for (int i = 0; i < live_objects; i++) {
             Address object_addr = cell_base + offsets[i] * kPointerSize;
             HeapObject* object = HeapObject::FromAddress(object_addr);
             ASSERT(Marking::IsBlack(Marking::MarkBitFrom(object)));
             int size = object->Size();
             MaybeObject* target = space->AllocateRaw(size, PagedSpace::MOVE_OBJECT);
             if (target->IsFailure()) {
               // OS refused to give us memory.
               V8::FatalProcessOutOfMemory("Evacuation");
               return;
+            }
             Object* target_object = target->ToObjectUnchecked();
             MigrateObject(HeapObject::cast(target_object)->address(),
                           object_addr,
                           size,
                           space->identity());
             ASSERT(object->map_word().IsForwardingAddress());
+          }
           // Clear marking bits for current cell.
           *cell = 0;
+        }
         p->ResetLiveBytes();
+      }
       void MarkCompactCollector::EvacuatePages() {
         int npages = evacuation_candidates_.length();
         for (int i = 0; i < npages; i++) {
           Page* p = evacuation_candidates_[i];
           ASSERT(p->IsEvacuationCandidate() ||
                  p->IsFlagSet(Page::RESCAN_ON_EVACUATION));
           if (p->IsEvacuationCandidate()) {
             // During compaction we might have to request a new page.
             // Check that space still have room for that.
             if (static_cast<PagedSpace*>(p->owner())->CanExpand()) {
               EvacuateLiveObjectsFromPage(p);
             } else {
               // Without room for expansion evacuation is not guaranteed to succeed.
               // Pessimistically abandon unevacuated pages.
               for (int j = i; j < npages; j++) {
                 Page* page = evacuation_candidates_[j];
                 slots_buffer_allocator_.DeallocateChain(page->slots_buffer_address());
                 page->ClearEvacuationCandidate();
                 page->SetFlag(Page::RESCAN_ON_EVACUATION);
                 page->InsertAfter(static_cast<PagedSpace*>(page->owner())->anchor());
+              }
               return;
+            }
+          }
+        }
+      }
       class EvacuationWeakObjectRetainer : public WeakObjectRetainer {
        public:
         virtual Object* RetainAs(Object* object) {
           if (object->IsHeapObject()) {
             HeapObject* heap_object = HeapObject::cast(object);
             MapWord map_word = heap_object->map_word();
             if (map_word.IsForwardingAddress()) {
               return map_word.ToForwardingAddress();
+            }
+          }
           return object;
+        }
       };
       static inline void UpdateSlot(Isolate* isolate,
                                     ObjectVisitor* v,
                                     SlotsBuffer::SlotType slot_type,
                                     Address addr) {
         switch (slot_type) {
           case SlotsBuffer::CODE_TARGET_SLOT: {
             RelocInfo rinfo(addr, RelocInfo::CODE_TARGET, 0, NULL);
             rinfo.Visit(isolate, v);
             break;
+          }
           case SlotsBuffer::CODE_ENTRY_SLOT: {
             v->VisitCodeEntry(addr);
             break;
+          }
           case SlotsBuffer::RELOCATED_CODE_OBJECT: {
             HeapObject* obj = HeapObject::FromAddress(addr);
             Code::cast(obj)->CodeIterateBody(v);
             break;
+          }
           case SlotsBuffer::DEBUG_TARGET_SLOT: {
             RelocInfo rinfo(addr, RelocInfo::DEBUG_BREAK_SLOT, 0, NULL);
             if (rinfo.IsPatchedDebugBreakSlotSequence()) rinfo.Visit(isolate, v);
             break;
+          }
           case SlotsBuffer::JS_RETURN_SLOT: {
             RelocInfo rinfo(addr, RelocInfo::JS_RETURN, 0, NULL);
             if (rinfo.IsPatchedReturnSequence()) rinfo.Visit(isolate, v);
             break;
+          }
           case SlotsBuffer::EMBEDDED_OBJECT_SLOT: {
             RelocInfo rinfo(addr, RelocInfo::EMBEDDED_OBJECT, 0, NULL);
             rinfo.Visit(isolate, v);
             break;
+          }
           default:
             UNREACHABLE();
             break;
+        }
+      }
       enum SweepingMode {
         SWEEP_ONLY,
         SWEEP_AND_VISIT_LIVE_OBJECTS
       };
       enum SkipListRebuildingMode {
         REBUILD_SKIP_LIST,
         IGNORE_SKIP_LIST
       };
       // Sweep a space precisely.  After this has been done the space can
       // be iterated precisely, hitting only the live objects.  Code space
       // is always swept precisely because we want to be able to iterate
       // over it.  Map space is swept precisely, because it is not compacted.
       // Slots in live objects pointing into evacuation candidates are updated
       // if requested.
       template<SweepingMode sweeping_mode, SkipListRebuildingMode skip_list_mode>
       static void SweepPrecisely(PagedSpace* space,
                                  Page* p,
                                  ObjectVisitor* v) {
         ASSERT(!p->IsEvacuationCandidate() && !p->WasSwept());
         ASSERT_EQ(skip_list_mode == REBUILD_SKIP_LIST,
                   space->identity() == CODE_SPACE);
         ASSERT((p->skip_list() == NULL) || (skip_list_mode == REBUILD_SKIP_LIST));
         double start_time = 0.0;
         if (FLAG_print_cumulative_gc_stat) {
           start_time = OS::TimeCurrentMillis();
+        }
         p->MarkSweptPrecisely();
         Address free_start = p->area_start();
         ASSERT(reinterpret_cast<intptr_t>(free_start) % (32 * kPointerSize) == 0);
         int offsets[16];
         SkipList* skip_list = p->skip_list();
         int curr_region = -1;
         if ((skip_list_mode == REBUILD_SKIP_LIST) && skip_list) {
           skip_list->Clear();
+        }
         for (MarkBitCellIterator it(p); !it.Done(); it.Advance()) {
           Address cell_base = it.CurrentCellBase();
           MarkBit::CellType* cell = it.CurrentCell();
           int live_objects = MarkWordToObjectStarts(*cell, offsets);
           int live_index = 0;
           for ( ; live_objects != 0; live_objects--) {
             Address free_end = cell_base + offsets[live_index++] * kPointerSize;
             if (free_end != free_start) {
               space->Free(free_start, static_cast<int>(free_end - free_start));
       #ifdef ENABLE_GDB_JIT_INTERFACE
               if (FLAG_gdbjit && space->identity() == CODE_SPACE) {
                 GDBJITInterface::RemoveCodeRange(free_start, free_end);
+              }
       #endif
+            }
             HeapObject* live_object = HeapObject::FromAddress(free_end);
             ASSERT(Marking::IsBlack(Marking::MarkBitFrom(live_object)));
             Map* map = live_object->map();
             int size = live_object->SizeFromMap(map);
             if (sweeping_mode == SWEEP_AND_VISIT_LIVE_OBJECTS) {
               live_object->IterateBody(map->instance_type(), size, v);
+            }
             if ((skip_list_mode == REBUILD_SKIP_LIST) && skip_list != NULL) {
               int new_region_start =
                   SkipList::RegionNumber(free_end);
               int new_region_end =
                   SkipList::RegionNumber(free_end + size - kPointerSize);
               if (new_region_start != curr_region ||
                   new_region_end != curr_region) {
                 skip_list->AddObject(free_end, size);
                 curr_region = new_region_end;
+              }
+            }
             free_start = free_end + size;
+          }
           // Clear marking bits for current cell.
           *cell = 0;
+        }
         if (free_start != p->area_end()) {
           space->Free(free_start, static_cast<int>(p->area_end() - free_start));
       #ifdef ENABLE_GDB_JIT_INTERFACE
           if (FLAG_gdbjit && space->identity() == CODE_SPACE) {
             GDBJITInterface::RemoveCodeRange(free_start, p->area_end());
+          }
       #endif
+        }
         p->ResetLiveBytes();
         if (FLAG_print_cumulative_gc_stat) {
           space->heap()->AddSweepingTime(OS::TimeCurrentMillis() - start_time);
+        }
+      }
       static bool SetMarkBitsUnderInvalidatedCode(Code* code, bool value) {
         Page* p = Page::FromAddress(code->address());
         if (p->IsEvacuationCandidate() ||
             p->IsFlagSet(Page::RESCAN_ON_EVACUATION)) {
           return false;
+        }
         Address code_start = code->address();
         Address code_end = code_start + code->Size();
         uint32_t start_index = MemoryChunk::FastAddressToMarkbitIndex(code_start);
         uint32_t end_index =
             MemoryChunk::FastAddressToMarkbitIndex(code_end - kPointerSize);
         Bitmap* b = p->markbits();
         MarkBit start_mark_bit = b->MarkBitFromIndex(start_index);
         MarkBit end_mark_bit = b->MarkBitFromIndex(end_index);
         MarkBit::CellType* start_cell = start_mark_bit.cell();
         MarkBit::CellType* end_cell = end_mark_bit.cell();
         if (value) {
           MarkBit::CellType start_mask = ~(start_mark_bit.mask() - 1);
           MarkBit::CellType end_mask = (end_mark_bit.mask() << 1) - 1;
           if (start_cell == end_cell) {
             *start_cell |= start_mask & end_mask;
           } else {
             *start_cell |= start_mask;
             for (MarkBit::CellType* cell = start_cell + 1; cell < end_cell; cell++) {
               *cell = ~0;
+            }
             *end_cell |= end_mask;
+          }
         } else {
           for (MarkBit::CellType* cell = start_cell ; cell <= end_cell; cell++) {
             *cell = 0;
+          }
+        }
         return true;
+      }
       static bool IsOnInvalidatedCodeObject(Address addr) {
         // We did not record any slots in large objects thus
         // we can safely go to the page from the slot address.
         Page* p = Page::FromAddress(addr);
         // First check owner's identity because old pointer and old data spaces
         // are swept lazily and might still have non-zero mark-bits on some
         // pages.
         if (p->owner()->identity() != CODE_SPACE) return false;
         // In code space only bits on evacuation candidates (but we don't record
         // any slots on them) and under invalidated code objects are non-zero.
         MarkBit mark_bit =
             p->markbits()->MarkBitFromIndex(Page::FastAddressToMarkbitIndex(addr));
         return mark_bit.Get();
+      }
       void MarkCompactCollector::InvalidateCode(Code* code) {
         if (heap_->incremental_marking()->IsCompacting() &&
             !ShouldSkipEvacuationSlotRecording(code)) {
           ASSERT(compacting_);
           // If the object is white than no slots were recorded on it yet.
           MarkBit mark_bit = Marking::MarkBitFrom(code);
           if (Marking::IsWhite(mark_bit)) return;
           invalidated_code_.Add(code);
+        }
+      }
       // Return true if the given code is deoptimized or will be deoptimized.
       bool MarkCompactCollector::WillBeDeoptimized(Code* code) {
         return code->marked_for_deoptimization();
+      }
       bool MarkCompactCollector::MarkInvalidatedCode() {
         bool code_marked = false;
         int length = invalidated_code_.length();
         for (int i = 0; i < length; i++) {
           Code* code = invalidated_code_[i];
           if (SetMarkBitsUnderInvalidatedCode(code, true)) {
             code_marked = true;
+          }
+        }
         return code_marked;
+      }
       void MarkCompactCollector::RemoveDeadInvalidatedCode() {
         int length = invalidated_code_.length();
         for (int i = 0; i < length; i++) {
           if (!IsMarked(invalidated_code_[i])) invalidated_code_[i] = NULL;
+        }
+      }
       void MarkCompactCollector::ProcessInvalidatedCode(ObjectVisitor* visitor) {
         int length = invalidated_code_.length();
         for (int i = 0; i < length; i++) {
           Code* code = invalidated_code_[i];
           if (code != NULL) {
             code->Iterate(visitor);
             SetMarkBitsUnderInvalidatedCode(code, false);
+          }
+        }
         invalidated_code_.Rewind(0);
+      }
       void MarkCompactCollector::EvacuateNewSpaceAndCandidates() {
         Heap::RelocationLock relocation_lock(heap());
         bool code_slots_filtering_required;
         { GCTracer::Scope gc_scope(tracer_, GCTracer::Scope::MC_SWEEP_NEWSPACE);
           code_slots_filtering_required = MarkInvalidatedCode();
           EvacuateNewSpace();
+        }
         { GCTracer::Scope gc_scope(tracer_, GCTracer::Scope::MC_EVACUATE_PAGES);
           EvacuatePages();
+        }
         // Second pass: find pointers to new space and update them.
         PointersUpdatingVisitor updating_visitor(heap());
         { GCTracer::Scope gc_scope(tracer_,
                                    GCTracer::Scope::MC_UPDATE_NEW_TO_NEW_POINTERS);
           // Update pointers in to space.
           SemiSpaceIterator to_it(heap()->new_space()->bottom(),
                                   heap()->new_space()->top());
           for (HeapObject* object = to_it.Next();
                object != NULL;
                object = to_it.Next()) {
             Map* map = object->map();
             object->IterateBody(map->instance_type(),
                                 object->SizeFromMap(map),
                                 &updating_visitor);
+          }
+        }
         { GCTracer::Scope gc_scope(tracer_,
                                    GCTracer::Scope::MC_UPDATE_ROOT_TO_NEW_POINTERS);
           // Update roots.
           heap_->IterateRoots(&updating_visitor, VISIT_ALL_IN_SWEEP_NEWSPACE);
+        }
         { GCTracer::Scope gc_scope(tracer_,
                                    GCTracer::Scope::MC_UPDATE_OLD_TO_NEW_POINTERS);
           StoreBufferRebuildScope scope(heap_,
                                         heap_->store_buffer(),
                                         &Heap::ScavengeStoreBufferCallback);
           heap_->store_buffer()->IteratePointersToNewSpaceAndClearMaps(
               &UpdatePointer);
+        }
         { GCTracer::Scope gc_scope(tracer_,
                                    GCTracer::Scope::MC_UPDATE_POINTERS_TO_EVACUATED);
           SlotsBuffer::UpdateSlotsRecordedIn(heap_,
                                              migration_slots_buffer_,
                                              code_slots_filtering_required);
           if (FLAG_trace_fragmentation) {
             PrintF("  migration slots buffer: %d\n",
                    SlotsBuffer::SizeOfChain(migration_slots_buffer_));
+          }
           if (compacting_ && was_marked_incrementally_) {
             // It's difficult to filter out slots recorded for large objects.
             LargeObjectIterator it(heap_->lo_space());
             for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
               // LargeObjectSpace is not swept yet thus we have to skip
               // dead objects explicitly.
               if (!IsMarked(obj)) continue;
               Page* p = Page::FromAddress(obj->address());
               if (p->IsFlagSet(Page::RESCAN_ON_EVACUATION)) {
                 obj->Iterate(&updating_visitor);
                 p->ClearFlag(Page::RESCAN_ON_EVACUATION);
+              }
+            }
+          }
+        }
         int npages = evacuation_candidates_.length();
         { GCTracer::Scope gc_scope(
             tracer_, GCTracer::Scope::MC_UPDATE_POINTERS_BETWEEN_EVACUATED);
           for (int i = 0; i < npages; i++) {
             Page* p = evacuation_candidates_[i];
             ASSERT(p->IsEvacuationCandidate() ||
                    p->IsFlagSet(Page::RESCAN_ON_EVACUATION));
             if (p->IsEvacuationCandidate()) {
               SlotsBuffer::UpdateSlotsRecordedIn(heap_,
                                                  p->slots_buffer(),
                                                  code_slots_filtering_required);
               if (FLAG_trace_fragmentation) {
                 PrintF("  page %p slots buffer: %d\n",
                        reinterpret_cast<void*>(p),
                        SlotsBuffer::SizeOfChain(p->slots_buffer()));
+              }
               // Important: skip list should be cleared only after roots were updated
               // because root iteration traverses the stack and might have to find
               // code objects from non-updated pc pointing into evacuation candidate.
               SkipList* list = p->skip_list();
               if (list != NULL) list->Clear();
             } else {
               if (FLAG_gc_verbose) {
                 PrintF("Sweeping 0x%" V8PRIxPTR " during evacuation.\n",
                        reinterpret_cast<intptr_t>(p));
+              }
               PagedSpace* space = static_cast<PagedSpace*>(p->owner());
               p->ClearFlag(MemoryChunk::RESCAN_ON_EVACUATION);
               switch (space->identity()) {
                 case OLD_DATA_SPACE:
                   SweepConservatively<SWEEP_SEQUENTIALLY>(space, NULL, p);
                   break;
                 case OLD_POINTER_SPACE:
                   SweepPrecisely<SWEEP_AND_VISIT_LIVE_OBJECTS, IGNORE_SKIP_LIST>(
                       space, p, &updating_visitor);
                   break;
                 case CODE_SPACE:
                   SweepPrecisely<SWEEP_AND_VISIT_LIVE_OBJECTS, REBUILD_SKIP_LIST>(
                       space, p, &updating_visitor);
                   break;
                 default:
                   UNREACHABLE();
                   break;
+              }
+            }
+          }
+        }
         GCTracer::Scope gc_scope(tracer_, GCTracer::Scope::MC_UPDATE_MISC_POINTERS);
         // Update pointers from cells.
         HeapObjectIterator cell_iterator(heap_->cell_space());
         for (HeapObject* cell = cell_iterator.Next();
              cell != NULL;
              cell = cell_iterator.Next()) {
           if (cell->IsCell()) {
             Cell::BodyDescriptor::IterateBody(cell, &updating_visitor);
+          }
+        }
         HeapObjectIterator js_global_property_cell_iterator(
             heap_->property_cell_space());
         for (HeapObject* cell = js_global_property_cell_iterator.Next();
              cell != NULL;
              cell = js_global_property_cell_iterator.Next()) {
           if (cell->IsPropertyCell()) {
             PropertyCell::BodyDescriptor::IterateBody(cell, &updating_visitor);
+          }
+        }
         // Update the head of the native contexts list in the heap.
         updating_visitor.VisitPointer(heap_->native_contexts_list_address());
         heap_->string_table()->Iterate(&updating_visitor);
         updating_visitor.VisitPointer(heap_->weak_object_to_code_table_address());
         if (heap_->weak_object_to_code_table()->IsHashTable()) {
           WeakHashTable* table =
               WeakHashTable::cast(heap_->weak_object_to_code_table());
           table->Iterate(&updating_visitor);
           table->Rehash(heap_->undefined_value());
+        }
         // Update pointers from external string table.
         heap_->UpdateReferencesInExternalStringTable(
             &UpdateReferenceInExternalStringTableEntry);
         if (!FLAG_watch_ic_patching) {
           // Update JSFunction pointers from the runtime profiler.
           heap()->isolate()->runtime_profiler()->UpdateSamplesAfterCompact(
               &updating_visitor);
+        }
         EvacuationWeakObjectRetainer evacuation_object_retainer;
         heap()->ProcessWeakReferences(&evacuation_object_retainer);
         // Visit invalidated code (we ignored all slots on it) and clear mark-bits
         // under it.
         ProcessInvalidatedCode(&updating_visitor);
         heap_->isolate()->inner_pointer_to_code_cache()->Flush();
       #ifdef VERIFY_HEAP
         if (FLAG_verify_heap) {
           VerifyEvacuation(heap_);
+        }
       #endif
         slots_buffer_allocator_.DeallocateChain(&migration_slots_buffer_);
         ASSERT(migration_slots_buffer_ == NULL);
+      }
       void MarkCompactCollector::UnlinkEvacuationCandidates() {
         int npages = evacuation_candidates_.length();
         for (int i = 0; i < npages; i++) {
           Page* p = evacuation_candidates_[i];
           if (!p->IsEvacuationCandidate()) continue;
           p->Unlink();
           p->ClearSweptPrecisely();
           p->ClearSweptConservatively();
+        }
+      }
       void MarkCompactCollector::ReleaseEvacuationCandidates() {
         int npages = evacuation_candidates_.length();
         for (int i = 0; i < npages; i++) {
           Page* p = evacuation_candidates_[i];
           if (!p->IsEvacuationCandidate()) continue;
           PagedSpace* space = static_cast<PagedSpace*>(p->owner());
           space->Free(p->area_start(), p->area_size());
           p->set_scan_on_scavenge(false);
           slots_buffer_allocator_.DeallocateChain(p->slots_buffer_address());
           p->ResetLiveBytes();
           space->ReleasePage(p, false);
+        }
         evacuation_candidates_.Rewind(0);
         compacting_ = false;
         heap()->FreeQueuedChunks();
+      }
       static const int kStartTableEntriesPerLine = 5;
       static const int kStartTableLines = 171;
       static const int kStartTableInvalidLine = 127;
       static const int kStartTableUnusedEntry = 126;
       #define _ kStartTableUnusedEntry
       #define X kStartTableInvalidLine
       // Mark-bit to object start offset table.
       //
       // The line is indexed by the mark bits in a byte.  The first number on
       // the line describes the number of live object starts for the line and the
       // other numbers on the line describe the offsets (in words) of the object
       // starts.
       //
       // Since objects are at least 2 words large we don't have entries for two
       // consecutive 1 bits.  All entries after 170 have at least 2 consecutive bits.
       char kStartTable[kStartTableLines * kStartTableEntriesPerLine] = {
 , _, _, _, _,  // 0
 , 0, _, _, _,  // 1
 , 1, _, _, _,  // 2
         X, _, _, _, _,  // 3
 , 2, _, _, _,  // 4
 , 0, 2, _, _,  // 5
         X, _, _, _, _,  // 6
         X, _, _, _, _,  // 7
 , 3, _, _, _,  // 8
 , 0, 3, _, _,  // 9
 , 1, 3, _, _,  // 10
         X, _, _, _, _,  // 11
         X, _, _, _, _,  // 12
         X, _, _, _, _,  // 13
         X, _, _, _, _,  // 14
         X, _, _, _, _,  // 15
 , 4, _, _, _,  // 16
 , 0, 4, _, _,  // 17
 , 1, 4, _, _,  // 18
         X, _, _, _, _,  // 19
 , 2, 4, _, _,  // 20
 , 0, 2, 4, _,  // 21
         X, _, _, _, _,  // 22
         X, _, _, _, _,  // 23
         X, _, _, _, _,  // 24
         X, _, _, _, _,  // 25
         X, _, _, _, _,  // 26
         X, _, _, _, _,  // 27
         X, _, _, _, _,  // 28
         X, _, _, _, _,  // 29
         X, _, _, _, _,  // 30
         X, _, _, _, _,  // 31
 , 5, _, _, _,  // 32
 , 0, 5, _, _,  // 33
 , 1, 5, _, _,  // 34
         X, _, _, _, _,  // 35
 , 2, 5, _, _,  // 36
 , 0, 2, 5, _,  // 37
         X, _, _, _, _,  // 38
         X, _, _, _, _,  // 39
 , 3, 5, _, _,  // 40
 , 0, 3, 5, _,  // 41
 , 1, 3, 5, _,  // 42
         X, _, _, _, _,  // 43
         X, _, _, _, _,  // 44
         X, _, _, _, _,  // 45
         X, _, _, _, _,  // 46
         X, _, _, _, _,  // 47
         X, _, _, _, _,  // 48
         X, _, _, _, _,  // 49
         X, _, _, _, _,  // 50
         X, _, _, _, _,  // 51
         X, _, _, _, _,  // 52
         X, _, _, _, _,  // 53
         X, _, _, _, _,  // 54
         X, _, _, _, _,  // 55
         X, _, _, _, _,  // 56
         X, _, _, _, _,  // 57
         X, _, _, _, _,  // 58
         X, _, _, _, _,  // 59
         X, _, _, _, _,  // 60
         X, _, _, _, _,  // 61
         X, _, _, _, _,  // 62
         X, _, _, _, _,  // 63
 , 6, _, _, _,  // 64
 , 0, 6, _, _,  // 65
 , 1, 6, _, _,  // 66
         X, _, _, _, _,  // 67
 , 2, 6, _, _,  // 68
 , 0, 2, 6, _,  // 69
         X, _, _, _, _,  // 70
         X, _, _, _, _,  // 71
 , 3, 6, _, _,  // 72
 , 0, 3, 6, _,  // 73
 , 1, 3, 6, _,  // 74
         X, _, _, _, _,  // 75
         X, _, _, _, _,  // 76
         X, _, _, _, _,  // 77
         X, _, _, _, _,  // 78
         X, _, _, _, _,  // 79
 , 4, 6, _, _,  // 80
 , 0, 4, 6, _,  // 81
 , 1, 4, 6, _,  // 82
         X, _, _, _, _,  // 83
 , 2, 4, 6, _,  // 84
 , 0, 2, 4, 6,  // 85
         X, _, _, _, _,  // 86
         X, _, _, _, _,  // 87
         X, _, _, _, _,  // 88
         X, _, _, _, _,  // 89
         X, _, _, _, _,  // 90
         X, _, _, _, _,  // 91
         X, _, _, _, _,  // 92
         X, _, _, _, _,  // 93
         X, _, _, _, _,  // 94
         X, _, _, _, _,  // 95
         X, _, _, _, _,  // 96
         X, _, _, _, _,  // 97
         X, _, _, _, _,  // 98
         X, _, _, _, _,  // 99
         X, _, _, _, _,  // 100
         X, _, _, _, _,  // 101
         X, _, _, _, _,  // 102
         X, _, _, _, _,  // 103
         X, _, _, _, _,  // 104
         X, _, _, _, _,  // 105
         X, _, _, _, _,  // 106
         X, _, _, _, _,  // 107
         X, _, _, _, _,  // 108
         X, _, _, _, _,  // 109
         X, _, _, _, _,  // 110
         X, _, _, _, _,  // 111
         X, _, _, _, _,  // 112
         X, _, _, _, _,  // 113
         X, _, _, _, _,  // 114
         X, _, _, _, _,  // 115
         X, _, _, _, _,  // 116
         X, _, _, _, _,  // 117
         X, _, _, _, _,  // 118
         X, _, _, _, _,  // 119
         X, _, _, _, _,  // 120
         X, _, _, _, _,  // 121
         X, _, _, _, _,  // 122
         X, _, _, _, _,  // 123
         X, _, _, _, _,  // 124
         X, _, _, _, _,  // 125
         X, _, _, _, _,  // 126
         X, _, _, _, _,  // 127
 , 7, _, _, _,  // 128
 , 0, 7, _, _,  // 129
 , 1, 7, _, _,  // 130
         X, _, _, _, _,  // 131
 , 2, 7, _, _,  // 132
 , 0, 2, 7, _,  // 133
         X, _, _, _, _,  // 134
         X, _, _, _, _,  // 135
 , 3, 7, _, _,  // 136
 , 0, 3, 7, _,  // 137
 , 1, 3, 7, _,  // 138
         X, _, _, _, _,  // 139
         X, _, _, _, _,  // 140
         X, _, _, _, _,  // 141
         X, _, _, _, _,  // 142
         X, _, _, _, _,  // 143
 , 4, 7, _, _,  // 144
 , 0, 4, 7, _,  // 145
 , 1, 4, 7, _,  // 146
         X, _, _, _, _,  // 147
 , 2, 4, 7, _,  // 148
 , 0, 2, 4, 7,  // 149
         X, _, _, _, _,  // 150
         X, _, _, _, _,  // 151
         X, _, _, _, _,  // 152
         X, _, _, _, _,  // 153
         X, _, _, _, _,  // 154
         X, _, _, _, _,  // 155
         X, _, _, _, _,  // 156
         X, _, _, _, _,  // 157
         X, _, _, _, _,  // 158
         X, _, _, _, _,  // 159
 , 5, 7, _, _,  // 160
 , 0, 5, 7, _,  // 161
 , 1, 5, 7, _,  // 162
         X, _, _, _, _,  // 163
 , 2, 5, 7, _,  // 164
 , 0, 2, 5, 7,  // 165
         X, _, _, _, _,  // 166
         X, _, _, _, _,  // 167
 , 3, 5, 7, _,  // 168
 , 0, 3, 5, 7,  // 169
 , 1, 3, 5, 7   // 170
       };
       #undef _
       #undef X
       // Takes a word of mark bits.  Returns the number of objects that start in the
       // range.  Puts the offsets of the words in the supplied array.
       static inline int MarkWordToObjectStarts(uint32_t mark_bits, int* starts) {
         int objects = 0;
         int offset = 0;
         // No consecutive 1 bits.
         ASSERT((mark_bits & 0x180) != 0x180);
         ASSERT((mark_bits & 0x18000) != 0x18000);
         ASSERT((mark_bits & 0x1800000) != 0x1800000);
         while (mark_bits != 0) {
           int byte = (mark_bits & 0xff);
           mark_bits >>= 8;
           if (byte != 0) {
             ASSERT(byte < kStartTableLines);  // No consecutive 1 bits.
             char* table = kStartTable + byte * kStartTableEntriesPerLine;
             int objects_in_these_8_words = table[0];
             ASSERT(objects_in_these_8_words != kStartTableInvalidLine);
             ASSERT(objects_in_these_8_words < kStartTableEntriesPerLine);
             for (int i = 0; i < objects_in_these_8_words; i++) {
               starts[objects++] = offset + table[1 + i];
+            }
+          }
           offset += 8;
+        }
         return objects;
+      }
       static inline Address DigestFreeStart(Address approximate_free_start,
                                             uint32_t free_start_cell) {
         ASSERT(free_start_cell != 0);
         // No consecutive 1 bits.
         ASSERT((free_start_cell & (free_start_cell << 1)) == 0);
         int offsets[16];
         uint32_t cell = free_start_cell;
         int offset_of_last_live;
         if ((cell & 0x80000000u) != 0) {
           // This case would overflow below.
           offset_of_last_live = 31;
         } else {
           // Remove all but one bit, the most significant.  This is an optimization
           // that may or may not be worthwhile.
           cell |= cell >> 16;
           cell |= cell >> 8;
           cell |= cell >> 4;
           cell |= cell >> 2;
           cell |= cell >> 1;
           cell = (cell + 1) >> 1;
           int live_objects = MarkWordToObjectStarts(cell, offsets);
           ASSERT(live_objects == 1);
           offset_of_last_live = offsets[live_objects - 1];
+        }
         Address last_live_start =
             approximate_free_start + offset_of_last_live * kPointerSize;
         HeapObject* last_live = HeapObject::FromAddress(last_live_start);
         Address free_start = last_live_start + last_live->Size();
         return free_start;
+      }
       static inline Address StartOfLiveObject(Address block_address, uint32_t cell) {
         ASSERT(cell != 0);
         // No consecutive 1 bits.
         ASSERT((cell & (cell << 1)) == 0);
         int offsets[16];
         if (cell == 0x80000000u) {  // Avoid overflow below.
           return block_address + 31 * kPointerSize;
+        }
         uint32_t first_set_bit = ((cell ^ (cell - 1)) + 1) >> 1;
         ASSERT((first_set_bit & cell) == first_set_bit);
         int live_objects = MarkWordToObjectStarts(first_set_bit, offsets);
         ASSERT(live_objects == 1);
         USE(live_objects);
         return block_address + offsets[0] * kPointerSize;
+      }
       template<MarkCompactCollector::SweepingParallelism mode>
       static intptr_t Free(PagedSpace* space,
                            FreeList* free_list,
                            Address start,
                            int size) {
         if (mode == MarkCompactCollector::SWEEP_SEQUENTIALLY) {
           return space->Free(start, size);
         } else {
           return size - free_list->Free(start, size);
+        }
+      }
       // Force instantiation of templatized SweepConservatively method for
       // SWEEP_SEQUENTIALLY mode.
       template intptr_t MarkCompactCollector::
           SweepConservatively<MarkCompactCollector::SWEEP_SEQUENTIALLY>(
               PagedSpace*, FreeList*, Page*);
       // Force instantiation of templatized SweepConservatively method for
       // SWEEP_IN_PARALLEL mode.
       template intptr_t MarkCompactCollector::
           SweepConservatively<MarkCompactCollector::SWEEP_IN_PARALLEL>(
               PagedSpace*, FreeList*, Page*);
       // Sweeps a space conservatively.  After this has been done the larger free
       // spaces have been put on the free list and the smaller ones have been
       // ignored and left untouched.  A free space is always either ignored or put
       // on the free list, never split up into two parts.  This is important
       // because it means that any FreeSpace maps left actually describe a region of
       // memory that can be ignored when scanning.  Dead objects other than free
       // spaces will not contain the free space map.
       template<MarkCompactCollector::SweepingParallelism mode>
       intptr_t MarkCompactCollector::SweepConservatively(PagedSpace* space,
                                                          FreeList* free_list,
                                                          Page* p) {
         ASSERT(!p->IsEvacuationCandidate() && !p->WasSwept());
         ASSERT((mode == MarkCompactCollector::SWEEP_IN_PARALLEL &&
                free_list != NULL) ||
                (mode == MarkCompactCollector::SWEEP_SEQUENTIALLY &&
                free_list == NULL));
         p->MarkSweptConservatively();
         intptr_t freed_bytes = 0;
         size_t size = 0;
         // Skip over all the dead objects at the start of the page and mark them free.
         Address cell_base = 0;
         MarkBit::CellType* cell = NULL;
         MarkBitCellIterator it(p);
         for (; !it.Done(); it.Advance()) {
           cell_base = it.CurrentCellBase();
           cell = it.CurrentCell();
           if (*cell != 0) break;
+        }
         if (it.Done()) {
           size = p->area_end() - p->area_start();
           freed_bytes += Free<mode>(space, free_list, p->area_start(),
                                     static_cast<int>(size));
           ASSERT_EQ(0, p->LiveBytes());
           return freed_bytes;
+        }
         // Grow the size of the start-of-page free space a little to get up to the
         // first live object.
         Address free_end = StartOfLiveObject(cell_base, *cell);
         // Free the first free space.
         size = free_end - p->area_start();
         freed_bytes += Free<mode>(space, free_list, p->area_start(),
                                   static_cast<int>(size));
         // The start of the current free area is represented in undigested form by
         // the address of the last 32-word section that contained a live object and
         // the marking bitmap for that cell, which describes where the live object
         // started.  Unless we find a large free space in the bitmap we will not
         // digest this pair into a real address.  We start the iteration here at the
         // first word in the marking bit map that indicates a live object.
         Address free_start = cell_base;
         MarkBit::CellType free_start_cell = *cell;
         for (; !it.Done(); it.Advance()) {
           cell_base = it.CurrentCellBase();
           cell = it.CurrentCell();
           if (*cell != 0) {
             // We have a live object.  Check approximately whether it is more than 32
             // words since the last live object.
             if (cell_base - free_start > 32 * kPointerSize) {
               free_start = DigestFreeStart(free_start, free_start_cell);
               if (cell_base - free_start > 32 * kPointerSize) {
                 // Now that we know the exact start of the free space it still looks
                 // like we have a large enough free space to be worth bothering with.
                 // so now we need to find the start of the first live object at the
                 // end of the free space.
                 free_end = StartOfLiveObject(cell_base, *cell);
                 freed_bytes += Free<mode>(space, free_list, free_start,
                                           static_cast<int>(free_end - free_start));
+              }
+            }
             // Update our undigested record of where the current free area started.
             free_start = cell_base;
             free_start_cell = *cell;
             // Clear marking bits for current cell.
             *cell = 0;
+          }
+        }
         // Handle the free space at the end of the page.
         if (cell_base - free_start > 32 * kPointerSize) {
           free_start = DigestFreeStart(free_start, free_start_cell);
           freed_bytes += Free<mode>(space, free_list, free_start,
                                     static_cast<int>(p->area_end() - free_start));
+        }
         p->ResetLiveBytes();
         return freed_bytes;
+      }
       void MarkCompactCollector::SweepInParallel(PagedSpace* space,
                                                  FreeList* private_free_list,
                                                  FreeList* free_list) {
         PageIterator it(space);
         while (it.has_next()) {
           Page* p = it.next();
           if (p->TryParallelSweeping()) {
             SweepConservatively<SWEEP_IN_PARALLEL>(space, private_free_list, p);
             free_list->Concatenate(private_free_list);
+          }
+        }
+      }
       void MarkCompactCollector::SweepSpace(PagedSpace* space, SweeperType sweeper) {
         space->set_was_swept_conservatively(sweeper == CONSERVATIVE ||
                                             sweeper == LAZY_CONSERVATIVE ||
                                             sweeper == PARALLEL_CONSERVATIVE ||
                                             sweeper == CONCURRENT_CONSERVATIVE);
         space->ClearStats();
         PageIterator it(space);
         int pages_swept = 0;
         bool lazy_sweeping_active = false;
         bool unused_page_present = false;
         bool parallel_sweeping_active = false;
         while (it.has_next()) {
           Page* p = it.next();
           ASSERT(p->parallel_sweeping() == 0);
           ASSERT(!p->IsEvacuationCandidate());
           // Clear sweeping flags indicating that marking bits are still intact.
           p->ClearSweptPrecisely();
           p->ClearSweptConservatively();
           if (p->IsFlagSet(Page::RESCAN_ON_EVACUATION)) {
             // Will be processed in EvacuateNewSpaceAndCandidates.
             ASSERT(evacuation_candidates_.length() > 0);
             continue;
+          }
           // One unused page is kept, all further are released before sweeping them.
           if (p->LiveBytes() == 0) {
             if (unused_page_present) {
               if (FLAG_gc_verbose) {
                 PrintF("Sweeping 0x%" V8PRIxPTR " released page.\n",
                        reinterpret_cast<intptr_t>(p));
+              }
               // Adjust unswept free bytes because releasing a page expects said
               // counter to be accurate for unswept pages.
               space->IncreaseUnsweptFreeBytes(p);
               space->ReleasePage(p, true);
               continue;
+            }
             unused_page_present = true;
+          }
           switch (sweeper) {
             case CONSERVATIVE: {
               if (FLAG_gc_verbose) {
                 PrintF("Sweeping 0x%" V8PRIxPTR " conservatively.\n",
                        reinterpret_cast<intptr_t>(p));
+              }
               SweepConservatively<SWEEP_SEQUENTIALLY>(space, NULL, p);
               pages_swept++;
               break;
+            }
             case LAZY_CONSERVATIVE: {
               if (lazy_sweeping_active) {
                 if (FLAG_gc_verbose) {
                   PrintF("Sweeping 0x%" V8PRIxPTR " lazily postponed.\n",
                          reinterpret_cast<intptr_t>(p));
+                }
                 space->IncreaseUnsweptFreeBytes(p);
               } else {
                 if (FLAG_gc_verbose) {
                   PrintF("Sweeping 0x%" V8PRIxPTR " conservatively.\n",
                          reinterpret_cast<intptr_t>(p));
+                }
                 SweepConservatively<SWEEP_SEQUENTIALLY>(space, NULL, p);
                 pages_swept++;
                 space->SetPagesToSweep(p->next_page());
                 lazy_sweeping_active = true;
+              }
               break;
+            }
             case CONCURRENT_CONSERVATIVE:
             case PARALLEL_CONSERVATIVE: {
               if (!parallel_sweeping_active) {
                 if (FLAG_gc_verbose) {
                   PrintF("Sweeping 0x%" V8PRIxPTR " conservatively.\n",
                          reinterpret_cast<intptr_t>(p));
+                }
                 SweepConservatively<SWEEP_SEQUENTIALLY>(space, NULL, p);
                 pages_swept++;
                 parallel_sweeping_active = true;
               } else {
                 if (FLAG_gc_verbose) {
                   PrintF("Sweeping 0x%" V8PRIxPTR " conservatively in parallel.\n",
                          reinterpret_cast<intptr_t>(p));
+                }
                 p->set_parallel_sweeping(1);
                 space->IncreaseUnsweptFreeBytes(p);
+              }
               break;
+            }
             case PRECISE: {
               if (FLAG_gc_verbose) {
                 PrintF("Sweeping 0x%" V8PRIxPTR " precisely.\n",
                        reinterpret_cast<intptr_t>(p));
+              }
               if (space->identity() == CODE_SPACE) {
                 SweepPrecisely<SWEEP_ONLY, REBUILD_SKIP_LIST>(space, p, NULL);
               } else {
                 SweepPrecisely<SWEEP_ONLY, IGNORE_SKIP_LIST>(space, p, NULL);
+              }
               pages_swept++;
               break;
+            }
             default: {
               UNREACHABLE();
+            }
+          }
+        }
         if (FLAG_gc_verbose) {
           PrintF("SweepSpace: %s (%d pages swept)\n",
                  AllocationSpaceName(space->identity()),
                  pages_swept);
+        }
         // Give pages that are queued to be freed back to the OS.
         heap()->FreeQueuedChunks();
+      }
       void MarkCompactCollector::SweepSpaces() {
         GCTracer::Scope gc_scope(tracer_, GCTracer::Scope::MC_SWEEP);
       #ifdef DEBUG
         state_ = SWEEP_SPACES;
       #endif
         SweeperType how_to_sweep =
             FLAG_lazy_sweeping ? LAZY_CONSERVATIVE : CONSERVATIVE;
         if (FLAG_parallel_sweeping) how_to_sweep = PARALLEL_CONSERVATIVE;
         if (FLAG_concurrent_sweeping) how_to_sweep = CONCURRENT_CONSERVATIVE;
         if (FLAG_expose_gc) how_to_sweep = CONSERVATIVE;
         if (sweep_precisely_) how_to_sweep = PRECISE;
         // Unlink evacuation candidates before sweeper threads access the list of
         // pages to avoid race condition.
         UnlinkEvacuationCandidates();
         // Noncompacting collections simply sweep the spaces to clear the mark
         // bits and free the nonlive blocks (for old and map spaces).  We sweep
         // the map space last because freeing non-live maps overwrites them and
         // the other spaces rely on possibly non-live maps to get the sizes for
         // non-live objects.
         SequentialSweepingScope scope(this);
         SweepSpace(heap()->old_pointer_space(), how_to_sweep);
         SweepSpace(heap()->old_data_space(), how_to_sweep);
         if (how_to_sweep == PARALLEL_CONSERVATIVE ||
             how_to_sweep == CONCURRENT_CONSERVATIVE) {
           // TODO(hpayer): fix race with concurrent sweeper
           StartSweeperThreads();
+        }
         if (how_to_sweep == PARALLEL_CONSERVATIVE) {
           WaitUntilSweepingCompleted();
+        }
         RemoveDeadInvalidatedCode();
         SweepSpace(heap()->code_space(), PRECISE);
         SweepSpace(heap()->cell_space(), PRECISE);
         SweepSpace(heap()->property_cell_space(), PRECISE);
         EvacuateNewSpaceAndCandidates();
         // ClearNonLiveTransitions depends on precise sweeping of map space to
         // detect whether unmarked map became dead in this collection or in one
         // of the previous ones.
         SweepSpace(heap()->map_space(), PRECISE);
         // Deallocate unmarked objects and clear marked bits for marked objects.
         heap_->lo_space()->FreeUnmarkedObjects();
         // Deallocate evacuated candidate pages.
         ReleaseEvacuationCandidates();
+      }
       void MarkCompactCollector::EnableCodeFlushing(bool enable) {
       #ifdef ENABLE_DEBUGGER_SUPPORT
         if (isolate()->debug()->IsLoaded() ||
             isolate()->debug()->has_break_points()) {
           enable = false;
+        }
       #endif
         if (enable) {
           if (code_flusher_ != NULL) return;
           code_flusher_ = new CodeFlusher(isolate());
         } else {
           if (code_flusher_ == NULL) return;
           code_flusher_->EvictAllCandidates();
           delete code_flusher_;
           code_flusher_ = NULL;
+        }
         if (FLAG_trace_code_flushing) {
           PrintF("[code-flushing is now %s]\n", enable ? "on" : "off");
+        }
+      }
       // TODO(1466) ReportDeleteIfNeeded is not called currently.
       // Our profiling tools do not expect intersections between
       // code objects. We should either reenable it or change our tools.
       void MarkCompactCollector::ReportDeleteIfNeeded(HeapObject* obj,
                                                       Isolate* isolate) {
       #ifdef ENABLE_GDB_JIT_INTERFACE
         if (obj->IsCode()) {
           GDBJITInterface::RemoveCode(reinterpret_cast<Code*>(obj));
+        }
       #endif
         if (obj->IsCode()) {
           PROFILE(isolate, CodeDeleteEvent(obj->address()));
+        }
+      }
       Isolate* MarkCompactCollector::isolate() const {
         return heap_->isolate();
+      }
       void MarkCompactCollector::Initialize() {
         MarkCompactMarkingVisitor::Initialize();
         IncrementalMarking::Initialize();
+      }
       bool SlotsBuffer::IsTypedSlot(ObjectSlot slot) {
         return reinterpret_cast<uintptr_t>(slot) < NUMBER_OF_SLOT_TYPES;
+      }
       bool SlotsBuffer::AddTo(SlotsBufferAllocator* allocator,
                               SlotsBuffer** buffer_address,
                               SlotType type,
                               Address addr,
                               AdditionMode mode) {
         SlotsBuffer* buffer = *buffer_address;
         if (buffer == NULL || !buffer->HasSpaceForTypedSlot()) {
           if (mode == FAIL_ON_OVERFLOW && ChainLengthThresholdReached(buffer)) {
             allocator->DeallocateChain(buffer_address);
             return false;
+          }
           buffer = allocator->AllocateBuffer(buffer);
           *buffer_address = buffer;
+        }
         ASSERT(buffer->HasSpaceForTypedSlot());
         buffer->Add(reinterpret_cast<ObjectSlot>(type));
         buffer->Add(reinterpret_cast<ObjectSlot>(addr));
         return true;
+      }
       static inline SlotsBuffer::SlotType SlotTypeForRMode(RelocInfo::Mode rmode) {
         if (RelocInfo::IsCodeTarget(rmode)) {
           return SlotsBuffer::CODE_TARGET_SLOT;
         } else if (RelocInfo::IsEmbeddedObject(rmode)) {
           return SlotsBuffer::EMBEDDED_OBJECT_SLOT;
         } else if (RelocInfo::IsDebugBreakSlot(rmode)) {
           return SlotsBuffer::DEBUG_TARGET_SLOT;
         } else if (RelocInfo::IsJSReturn(rmode)) {
           return SlotsBuffer::JS_RETURN_SLOT;
+        }
         UNREACHABLE();
         return SlotsBuffer::NUMBER_OF_SLOT_TYPES;
+      }
       void MarkCompactCollector::RecordRelocSlot(RelocInfo* rinfo, Object* target) {
         Page* target_page = Page::FromAddress(reinterpret_cast<Address>(target));
         if (target_page->IsEvacuationCandidate() &&
             (rinfo->host() == NULL ||
              !ShouldSkipEvacuationSlotRecording(rinfo->host()))) {
           if (!SlotsBuffer::AddTo(&slots_buffer_allocator_,
                                   target_page->slots_buffer_address(),
                                   SlotTypeForRMode(rinfo->rmode()),
                                   rinfo->pc(),
                                   SlotsBuffer::FAIL_ON_OVERFLOW)) {
             EvictEvacuationCandidate(target_page);
+          }
+        }
+      }
       void MarkCompactCollector::RecordCodeEntrySlot(Address slot, Code* target) {
         Page* target_page = Page::FromAddress(reinterpret_cast<Address>(target));
         if (target_page->IsEvacuationCandidate() &&
             !ShouldSkipEvacuationSlotRecording(reinterpret_cast<Object**>(slot))) {
           if (!SlotsBuffer::AddTo(&slots_buffer_allocator_,
                                   target_page->slots_buffer_address(),
                                   SlotsBuffer::CODE_ENTRY_SLOT,
                                   slot,
                                   SlotsBuffer::FAIL_ON_OVERFLOW)) {
             EvictEvacuationCandidate(target_page);
+          }
+        }
+      }
       void MarkCompactCollector::RecordCodeTargetPatch(Address pc, Code* target) {
         ASSERT(heap()->gc_state() == Heap::MARK_COMPACT);
         if (is_compacting()) {
           Code* host = isolate()->inner_pointer_to_code_cache()->
               GcSafeFindCodeForInnerPointer(pc);
           MarkBit mark_bit = Marking::MarkBitFrom(host);
           if (Marking::IsBlack(mark_bit)) {
             RelocInfo rinfo(pc, RelocInfo::CODE_TARGET, 0, host);
             RecordRelocSlot(&rinfo, target);
+          }
+        }
+      }
       static inline SlotsBuffer::SlotType DecodeSlotType(
           SlotsBuffer::ObjectSlot slot) {
         return static_cast<SlotsBuffer::SlotType>(reinterpret_cast<intptr_t>(slot));
+      }
       void SlotsBuffer::UpdateSlots(Heap* heap) {
         PointersUpdatingVisitor v(heap);
         for (int slot_idx = 0; slot_idx < idx_; ++slot_idx) {
           ObjectSlot slot = slots_[slot_idx];
           if (!IsTypedSlot(slot)) {
             PointersUpdatingVisitor::UpdateSlot(heap, slot);
           } else {
             ++slot_idx;
             ASSERT(slot_idx < idx_);
             UpdateSlot(heap->isolate(),
                        &v,
                        DecodeSlotType(slot),
                        reinterpret_cast<Address>(slots_[slot_idx]));
+          }
+        }
+      }
       void SlotsBuffer::UpdateSlotsWithFilter(Heap* heap) {
         PointersUpdatingVisitor v(heap);
         for (int slot_idx = 0; slot_idx < idx_; ++slot_idx) {
           ObjectSlot slot = slots_[slot_idx];
           if (!IsTypedSlot(slot)) {
             if (!IsOnInvalidatedCodeObject(reinterpret_cast<Address>(slot))) {
               PointersUpdatingVisitor::UpdateSlot(heap, slot);
+            }
           } else {
             ++slot_idx;
             ASSERT(slot_idx < idx_);
             Address pc = reinterpret_cast<Address>(slots_[slot_idx]);
             if (!IsOnInvalidatedCodeObject(pc)) {
               UpdateSlot(heap->isolate(),
                          &v,
                          DecodeSlotType(slot),
                          reinterpret_cast<Address>(slots_[slot_idx]));
+            }
+          }
+        }
+      }
       SlotsBuffer* SlotsBufferAllocator::AllocateBuffer(SlotsBuffer* next_buffer) {
         return new SlotsBuffer(next_buffer);
+      }
       void SlotsBufferAllocator::DeallocateBuffer(SlotsBuffer* buffer) {
         delete buffer;
+      }
       void SlotsBufferAllocator::DeallocateChain(SlotsBuffer** buffer_address) {
         SlotsBuffer* buffer = *buffer_address;
         while (buffer != NULL) {
           SlotsBuffer* next_buffer = buffer->next();
           DeallocateBuffer(buffer);
           buffer = next_buffer;
+        }
         *buffer_address = NULL;
+      }
       } }  // namespace v8::internal