Move a bunch of GC related files to heap/ subdirectory

src/heap.cc

-// Copyright 2012 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "src/v8.h"
-
-#include "src/accessors.h"
-#include "src/api.h"
-#include "src/base/once.h"
-#include "src/base/utils/random-number-generator.h"
-#include "src/bootstrapper.h"
-#include "src/codegen.h"
-#include "src/compilation-cache.h"
-#include "src/conversions.h"
-#include "src/cpu-profiler.h"
-#include "src/debug.h"
-#include "src/deoptimizer.h"
-#include "src/global-handles.h"
-#include "src/heap-profiler.h"
-#include "src/incremental-marking.h"
-#include "src/isolate-inl.h"
-#include "src/mark-compact.h"
-#include "src/natives.h"
-#include "src/objects-visiting-inl.h"
-#include "src/objects-visiting.h"
-#include "src/runtime-profiler.h"
-#include "src/scopeinfo.h"
-#include "src/snapshot.h"
-#include "src/store-buffer.h"
-#include "src/utils.h"
-#include "src/v8threads.h"
-#include "src/vm-state-inl.h"
-
-#if V8_TARGET_ARCH_ARM && !V8_INTERPRETED_REGEXP
-#include "src/regexp-macro-assembler.h"  // NOLINT
-#include "src/arm/regexp-macro-assembler-arm.h"  // NOLINT
-#endif
-#if V8_TARGET_ARCH_MIPS && !V8_INTERPRETED_REGEXP
-#include "src/regexp-macro-assembler.h"  // NOLINT
-#include "src/mips/regexp-macro-assembler-mips.h"  // NOLINT
-#endif
-#if V8_TARGET_ARCH_MIPS64 && !V8_INTERPRETED_REGEXP
-#include "src/regexp-macro-assembler.h"
-#include "src/mips64/regexp-macro-assembler-mips64.h"
-#endif
-
-namespace v8 {
-namespace internal {
-
-
-Heap::Heap()
-    : amount_of_external_allocated_memory_(0),
-      amount_of_external_allocated_memory_at_last_global_gc_(0),
-      isolate_(NULL),
-      code_range_size_(0),
-      // semispace_size_ should be a power of 2 and old_generation_size_ should
-      // be a multiple of Page::kPageSize.
-      reserved_semispace_size_(8 * (kPointerSize / 4) * MB),
-      max_semi_space_size_(8 * (kPointerSize / 4) * MB),
-      initial_semispace_size_(Page::kPageSize),
-      max_old_generation_size_(700ul * (kPointerSize / 4) * MB),
-      max_executable_size_(256ul * (kPointerSize / 4) * MB),
-      // Variables set based on semispace_size_ and old_generation_size_ in
-      // ConfigureHeap.
-      // Will be 4 * reserved_semispace_size_ to ensure that young
-      // generation can be aligned to its size.
-      maximum_committed_(0),
-      survived_since_last_expansion_(0),
-      sweep_generation_(0),
-      always_allocate_scope_depth_(0),
-      contexts_disposed_(0),
-      global_ic_age_(0),
-      flush_monomorphic_ics_(false),
-      scan_on_scavenge_pages_(0),
-      new_space_(this),
-      old_pointer_space_(NULL),
-      old_data_space_(NULL),
-      code_space_(NULL),
-      map_space_(NULL),
-      cell_space_(NULL),
-      property_cell_space_(NULL),
-      lo_space_(NULL),
-      gc_state_(NOT_IN_GC),
-      gc_post_processing_depth_(0),
-      allocations_count_(0),
-      raw_allocations_hash_(0),
-      dump_allocations_hash_countdown_(FLAG_dump_allocations_digest_at_alloc),
-      ms_count_(0),
-      gc_count_(0),
-      remembered_unmapped_pages_index_(0),
-      unflattened_strings_length_(0),
-#ifdef DEBUG
-      allocation_timeout_(0),
-#endif  // DEBUG
-      old_generation_allocation_limit_(kMinimumOldGenerationAllocationLimit),
-      old_gen_exhausted_(false),
-      inline_allocation_disabled_(false),
-      store_buffer_rebuilder_(store_buffer()),
-      hidden_string_(NULL),
-      gc_safe_size_of_old_object_(NULL),
-      total_regexp_code_generated_(0),
-      tracer_(this),
-      high_survival_rate_period_length_(0),
-      promoted_objects_size_(0),
-      promotion_rate_(0),
-      semi_space_copied_object_size_(0),
-      semi_space_copied_rate_(0),
-      nodes_died_in_new_space_(0),
-      nodes_copied_in_new_space_(0),
-      nodes_promoted_(0),
-      maximum_size_scavenges_(0),
-      max_gc_pause_(0.0),
-      total_gc_time_ms_(0.0),
-      max_alive_after_gc_(0),
-      min_in_mutator_(kMaxInt),
-      marking_time_(0.0),
-      sweeping_time_(0.0),
-      mark_compact_collector_(this),
-      store_buffer_(this),
-      marking_(this),
-      incremental_marking_(this),
-      number_idle_notifications_(0),
-      last_idle_notification_gc_count_(0),
-      last_idle_notification_gc_count_init_(false),
-      mark_sweeps_since_idle_round_started_(0),
-      gc_count_at_last_idle_gc_(0),
-      scavenges_since_last_idle_round_(kIdleScavengeThreshold),
-      full_codegen_bytes_generated_(0),
-      crankshaft_codegen_bytes_generated_(0),
-      gcs_since_last_deopt_(0),
-#ifdef VERIFY_HEAP
-      no_weak_object_verification_scope_depth_(0),
-#endif
-      allocation_sites_scratchpad_length_(0),
-      promotion_queue_(this),
-      configured_(false),
-      external_string_table_(this),
-      chunks_queued_for_free_(NULL),
-      gc_callbacks_depth_(0) {
-  // Allow build-time customization of the max semispace size. Building
-  // V8 with snapshots and a non-default max semispace size is much
-  // easier if you can define it as part of the build environment.
-#if defined(V8_MAX_SEMISPACE_SIZE)
-  max_semi_space_size_ = reserved_semispace_size_ = V8_MAX_SEMISPACE_SIZE;
-#endif
-
-  // Ensure old_generation_size_ is a multiple of kPageSize.
-  DCHECK(MB >= Page::kPageSize);
-
-  memset(roots_, 0, sizeof(roots_[0]) * kRootListLength);
-  set_native_contexts_list(NULL);
-  set_array_buffers_list(Smi::FromInt(0));
-  set_allocation_sites_list(Smi::FromInt(0));
-  set_encountered_weak_collections(Smi::FromInt(0));
-  // Put a dummy entry in the remembered pages so we can find the list the
-  // minidump even if there are no real unmapped pages.
-  RememberUnmappedPage(NULL, false);
-
-  ClearObjectStats(true);
-}
-
-
-intptr_t Heap::Capacity() {
-  if (!HasBeenSetUp()) return 0;
-
-  return new_space_.Capacity() +
-      old_pointer_space_->Capacity() +
-      old_data_space_->Capacity() +
-      code_space_->Capacity() +
-      map_space_->Capacity() +
-      cell_space_->Capacity() +
-      property_cell_space_->Capacity();
-}
-
-
-intptr_t Heap::CommittedMemory() {
-  if (!HasBeenSetUp()) return 0;
-
-  return new_space_.CommittedMemory() +
-      old_pointer_space_->CommittedMemory() +
-      old_data_space_->CommittedMemory() +
-      code_space_->CommittedMemory() +
-      map_space_->CommittedMemory() +
-      cell_space_->CommittedMemory() +
-      property_cell_space_->CommittedMemory() +
-      lo_space_->Size();
-}
-
-
-size_t Heap::CommittedPhysicalMemory() {
-  if (!HasBeenSetUp()) return 0;
-
-  return new_space_.CommittedPhysicalMemory() +
-      old_pointer_space_->CommittedPhysicalMemory() +
-      old_data_space_->CommittedPhysicalMemory() +
-      code_space_->CommittedPhysicalMemory() +
-      map_space_->CommittedPhysicalMemory() +
-      cell_space_->CommittedPhysicalMemory() +
-      property_cell_space_->CommittedPhysicalMemory() +
-      lo_space_->CommittedPhysicalMemory();
-}
-
-
-intptr_t Heap::CommittedMemoryExecutable() {
-  if (!HasBeenSetUp()) return 0;
-
-  return isolate()->memory_allocator()->SizeExecutable();
-}
-
-
-void Heap::UpdateMaximumCommitted() {
-  if (!HasBeenSetUp()) return;
-
-  intptr_t current_committed_memory = CommittedMemory();
-  if (current_committed_memory > maximum_committed_) {
-    maximum_committed_ = current_committed_memory;
-  }
-}
-
-
-intptr_t Heap::Available() {
-  if (!HasBeenSetUp()) return 0;
-
-  return new_space_.Available() +
-      old_pointer_space_->Available() +
-      old_data_space_->Available() +
-      code_space_->Available() +
-      map_space_->Available() +
-      cell_space_->Available() +
-      property_cell_space_->Available();
-}
-
-
-bool Heap::HasBeenSetUp() {
-  return old_pointer_space_ != NULL &&
-         old_data_space_ != NULL &&
-         code_space_ != NULL &&
-         map_space_ != NULL &&
-         cell_space_ != NULL &&
-         property_cell_space_ != NULL &&
-         lo_space_ != NULL;
-}
-
-
-int Heap::GcSafeSizeOfOldObject(HeapObject* object) {
-  if (IntrusiveMarking::IsMarked(object)) {
-    return IntrusiveMarking::SizeOfMarkedObject(object);
-  }
-  return object->SizeFromMap(object->map());
-}
-
-
-GarbageCollector Heap::SelectGarbageCollector(AllocationSpace space,
-                                              const char** reason) {
-  // Is global GC requested?
-  if (space != NEW_SPACE) {
-    isolate_->counters()->gc_compactor_caused_by_request()->Increment();
-    *reason = "GC in old space requested";
-    return MARK_COMPACTOR;
-  }
-
-  if (FLAG_gc_global || (FLAG_stress_compaction && (gc_count_ & 1) != 0)) {
-    *reason = "GC in old space forced by flags";
-    return MARK_COMPACTOR;
-  }
-
-  // Is enough data promoted to justify a global GC?
-  if (OldGenerationAllocationLimitReached()) {
-    isolate_->counters()->gc_compactor_caused_by_promoted_data()->Increment();
-    *reason = "promotion limit reached";
-    return MARK_COMPACTOR;
-  }
-
-  // Have allocation in OLD and LO failed?
-  if (old_gen_exhausted_) {
-    isolate_->counters()->
-        gc_compactor_caused_by_oldspace_exhaustion()->Increment();
-    *reason = "old generations exhausted";
-    return MARK_COMPACTOR;
-  }
-
-  // Is there enough space left in OLD to guarantee that a scavenge can
-  // succeed?
-  //
-  // Note that MemoryAllocator->MaxAvailable() undercounts the memory available
-  // for object promotion. It counts only the bytes that the memory
-  // allocator has not yet allocated from the OS and assigned to any space,
-  // and does not count available bytes already in the old space or code
-  // space.  Undercounting is safe---we may get an unrequested full GC when
-  // a scavenge would have succeeded.
-  if (isolate_->memory_allocator()->MaxAvailable() <= new_space_.Size()) {
-    isolate_->counters()->
-        gc_compactor_caused_by_oldspace_exhaustion()->Increment();
-    *reason = "scavenge might not succeed";
-    return MARK_COMPACTOR;
-  }
-
-  // Default
-  *reason = NULL;
-  return SCAVENGER;
-}
-
-
-// TODO(1238405): Combine the infrastructure for --heap-stats and
-// --log-gc to avoid the complicated preprocessor and flag testing.
-void Heap::ReportStatisticsBeforeGC() {
-  // Heap::ReportHeapStatistics will also log NewSpace statistics when
-  // compiled --log-gc is set.  The following logic is used to avoid
-  // double logging.
-#ifdef DEBUG
-  if (FLAG_heap_stats || FLAG_log_gc) new_space_.CollectStatistics();
-  if (FLAG_heap_stats) {
-    ReportHeapStatistics("Before GC");
-  } else if (FLAG_log_gc) {
-    new_space_.ReportStatistics();
-  }
-  if (FLAG_heap_stats || FLAG_log_gc) new_space_.ClearHistograms();
-#else
-  if (FLAG_log_gc) {
-    new_space_.CollectStatistics();
-    new_space_.ReportStatistics();
-    new_space_.ClearHistograms();
-  }
-#endif  // DEBUG
-}
-
-
-void Heap::PrintShortHeapStatistics() {
-  if (!FLAG_trace_gc_verbose) return;
-  PrintPID("Memory allocator,   used: %6" V8_PTR_PREFIX "d KB"
-               ", available: %6" V8_PTR_PREFIX "d KB\n",
-           isolate_->memory_allocator()->Size() / KB,
-           isolate_->memory_allocator()->Available() / KB);
-  PrintPID("New space,          used: %6" V8_PTR_PREFIX "d KB"
-               ", available: %6" V8_PTR_PREFIX "d KB"
-               ", committed: %6" V8_PTR_PREFIX "d KB\n",
-           new_space_.Size() / KB,
-           new_space_.Available() / KB,
-           new_space_.CommittedMemory() / KB);
-  PrintPID("Old pointers,       used: %6" V8_PTR_PREFIX "d KB"
-               ", available: %6" V8_PTR_PREFIX "d KB"
-               ", committed: %6" V8_PTR_PREFIX "d KB\n",
-           old_pointer_space_->SizeOfObjects() / KB,
-           old_pointer_space_->Available() / KB,
-           old_pointer_space_->CommittedMemory() / KB);
-  PrintPID("Old data space,     used: %6" V8_PTR_PREFIX "d KB"
-               ", available: %6" V8_PTR_PREFIX "d KB"
-               ", committed: %6" V8_PTR_PREFIX "d KB\n",
-           old_data_space_->SizeOfObjects() / KB,
-           old_data_space_->Available() / KB,
-           old_data_space_->CommittedMemory() / KB);
-  PrintPID("Code space,         used: %6" V8_PTR_PREFIX "d KB"
-               ", available: %6" V8_PTR_PREFIX "d KB"
-               ", committed: %6" V8_PTR_PREFIX "d KB\n",
-           code_space_->SizeOfObjects() / KB,
-           code_space_->Available() / KB,
-           code_space_->CommittedMemory() / KB);
-  PrintPID("Map space,          used: %6" V8_PTR_PREFIX "d KB"
-               ", available: %6" V8_PTR_PREFIX "d KB"
-               ", committed: %6" V8_PTR_PREFIX "d KB\n",
-           map_space_->SizeOfObjects() / KB,
-           map_space_->Available() / KB,
-           map_space_->CommittedMemory() / KB);
-  PrintPID("Cell space,         used: %6" V8_PTR_PREFIX "d KB"
-               ", available: %6" V8_PTR_PREFIX "d KB"
-               ", committed: %6" V8_PTR_PREFIX "d KB\n",
-           cell_space_->SizeOfObjects() / KB,
-           cell_space_->Available() / KB,
-           cell_space_->CommittedMemory() / KB);
-  PrintPID("PropertyCell space, used: %6" V8_PTR_PREFIX "d KB"
-               ", available: %6" V8_PTR_PREFIX "d KB"
-               ", committed: %6" V8_PTR_PREFIX "d KB\n",
-           property_cell_space_->SizeOfObjects() / KB,
-           property_cell_space_->Available() / KB,
-           property_cell_space_->CommittedMemory() / KB);
-  PrintPID("Large object space, used: %6" V8_PTR_PREFIX "d KB"
-               ", available: %6" V8_PTR_PREFIX "d KB"
-               ", committed: %6" V8_PTR_PREFIX "d KB\n",
-           lo_space_->SizeOfObjects() / KB,
-           lo_space_->Available() / KB,
-           lo_space_->CommittedMemory() / KB);
-  PrintPID("All spaces,         used: %6" V8_PTR_PREFIX "d KB"
-               ", available: %6" V8_PTR_PREFIX "d KB"
-               ", committed: %6" V8_PTR_PREFIX "d KB\n",
-           this->SizeOfObjects() / KB,
-           this->Available() / KB,
-           this->CommittedMemory() / KB);
-  PrintPID("External memory reported: %6" V8_PTR_PREFIX "d KB\n",
-           static_cast<intptr_t>(amount_of_external_allocated_memory_ / KB));
-  PrintPID("Total time spent in GC  : %.1f ms\n", total_gc_time_ms_);
-}
-
-
-// TODO(1238405): Combine the infrastructure for --heap-stats and
-// --log-gc to avoid the complicated preprocessor and flag testing.
-void Heap::ReportStatisticsAfterGC() {
-  // Similar to the before GC, we use some complicated logic to ensure that
-  // NewSpace statistics are logged exactly once when --log-gc is turned on.
-#if defined(DEBUG)
-  if (FLAG_heap_stats) {
-    new_space_.CollectStatistics();
-    ReportHeapStatistics("After GC");
-  } else if (FLAG_log_gc) {
-    new_space_.ReportStatistics();
-  }
-#else
-  if (FLAG_log_gc) new_space_.ReportStatistics();
-#endif  // DEBUG
-}
-
-
-void Heap::GarbageCollectionPrologue() {
-  {  AllowHeapAllocation for_the_first_part_of_prologue;
-    ClearJSFunctionResultCaches();
-    gc_count_++;
-    unflattened_strings_length_ = 0;
-
-    if (FLAG_flush_code && FLAG_flush_code_incrementally) {
-      mark_compact_collector()->EnableCodeFlushing(true);
-    }
-
-#ifdef VERIFY_HEAP
-    if (FLAG_verify_heap) {
-      Verify();
-    }
-#endif
-  }
-
-  // Reset GC statistics.
-  promoted_objects_size_ = 0;
-  semi_space_copied_object_size_ = 0;
-  nodes_died_in_new_space_ = 0;
-  nodes_copied_in_new_space_ = 0;
-  nodes_promoted_ = 0;
-
-  UpdateMaximumCommitted();
-
-#ifdef DEBUG
-  DCHECK(!AllowHeapAllocation::IsAllowed() && gc_state_ == NOT_IN_GC);
-
-  if (FLAG_gc_verbose) Print();
-
-  ReportStatisticsBeforeGC();
-#endif  // DEBUG
-
-  store_buffer()->GCPrologue();
-
-  if (isolate()->concurrent_osr_enabled()) {
-    isolate()->optimizing_compiler_thread()->AgeBufferedOsrJobs();
-  }
-
-  if (new_space_.IsAtMaximumCapacity()) {
-    maximum_size_scavenges_++;
-  } else {
-    maximum_size_scavenges_ = 0;
-  }
-  CheckNewSpaceExpansionCriteria();
-}
-
-
-intptr_t Heap::SizeOfObjects() {
-  intptr_t total = 0;
-  AllSpaces spaces(this);
-  for (Space* space = spaces.next(); space != NULL; space = spaces.next()) {
-    total += space->SizeOfObjects();
-  }
-  return total;
-}
-
-
-void Heap::ClearAllICsByKind(Code::Kind kind) {
-  HeapObjectIterator it(code_space());
-
-  for (Object* object = it.Next(); object != NULL; object = it.Next()) {
-    Code* code = Code::cast(object);
-    Code::Kind current_kind = code->kind();
-    if (current_kind == Code::FUNCTION ||
-        current_kind == Code::OPTIMIZED_FUNCTION) {
-      code->ClearInlineCaches(kind);
-    }
-  }
-}
-
-
-void Heap::RepairFreeListsAfterBoot() {
-  PagedSpaces spaces(this);
-  for (PagedSpace* space = spaces.next();
-       space != NULL;
-       space = spaces.next()) {
-    space->RepairFreeListsAfterBoot();
-  }
-}
-
-
-void Heap::ProcessPretenuringFeedback() {
-  if (FLAG_allocation_site_pretenuring) {
-    int tenure_decisions = 0;
-    int dont_tenure_decisions = 0;
-    int allocation_mementos_found = 0;
-    int allocation_sites = 0;
-    int active_allocation_sites = 0;
-
-    // If the scratchpad overflowed, we have to iterate over the allocation
-    // sites list.
-    // TODO(hpayer): We iterate over the whole list of allocation sites when
-    // we grew to the maximum semi-space size to deopt maybe tenured
-    // allocation sites. We could hold the maybe tenured allocation sites
-    // in a seperate data structure if this is a performance problem.
-    bool deopt_maybe_tenured = DeoptMaybeTenuredAllocationSites();
-    bool use_scratchpad =
-         allocation_sites_scratchpad_length_ < kAllocationSiteScratchpadSize &&
-         !deopt_maybe_tenured;
-
-    int i = 0;
-    Object* list_element = allocation_sites_list();
-    bool trigger_deoptimization = false;
-    bool maximum_size_scavenge = MaximumSizeScavenge();
-    while (use_scratchpad ?
-              i < allocation_sites_scratchpad_length_ :
-              list_element->IsAllocationSite()) {
-      AllocationSite* site = use_scratchpad ?
-          AllocationSite::cast(allocation_sites_scratchpad()->get(i)) :
-          AllocationSite::cast(list_element);
-      allocation_mementos_found += site->memento_found_count();
-      if (site->memento_found_count() > 0) {
-        active_allocation_sites++;
-        if (site->DigestPretenuringFeedback(maximum_size_scavenge)) {
-          trigger_deoptimization = true;
-        }
-        if (site->GetPretenureMode() == TENURED) {
-          tenure_decisions++;
-        } else {
-          dont_tenure_decisions++;
-        }
-        allocation_sites++;
-      }
-
-      if (deopt_maybe_tenured && site->IsMaybeTenure()) {
-        site->set_deopt_dependent_code(true);
-        trigger_deoptimization = true;
-      }
-
-      if (use_scratchpad) {
-        i++;
-      } else {
-        list_element = site->weak_next();
-      }
-    }
-
-    if (trigger_deoptimization) {
-      isolate_->stack_guard()->RequestDeoptMarkedAllocationSites();
-    }
-
-    FlushAllocationSitesScratchpad();
-
-    if (FLAG_trace_pretenuring_statistics &&
-        (allocation_mementos_found > 0 ||
-         tenure_decisions > 0 ||
-         dont_tenure_decisions > 0)) {
-      PrintF("GC: (mode, #visited allocation sites, #active allocation sites, "
-             "#mementos, #tenure decisions, #donttenure decisions) "
-             "(%s, %d, %d, %d, %d, %d)\n",
-             use_scratchpad ? "use scratchpad" : "use list",
-             allocation_sites,
-             active_allocation_sites,
-             allocation_mementos_found,
-             tenure_decisions,
-             dont_tenure_decisions);
-    }
-  }
-}
-
-
-void Heap::DeoptMarkedAllocationSites() {
-  // TODO(hpayer): If iterating over the allocation sites list becomes a
-  // performance issue, use a cache heap data structure instead (similar to the
-  // allocation sites scratchpad).
-  Object* list_element = allocation_sites_list();
-  while (list_element->IsAllocationSite()) {
-    AllocationSite* site = AllocationSite::cast(list_element);
-    if (site->deopt_dependent_code()) {
-      site->dependent_code()->MarkCodeForDeoptimization(
-          isolate_,
-          DependentCode::kAllocationSiteTenuringChangedGroup);
-      site->set_deopt_dependent_code(false);
-    }
-    list_element = site->weak_next();
-  }
-  Deoptimizer::DeoptimizeMarkedCode(isolate_);
-}
-
-
-void Heap::GarbageCollectionEpilogue() {
-  store_buffer()->GCEpilogue();
-
-  // In release mode, we only zap the from space under heap verification.
-  if (Heap::ShouldZapGarbage()) {
-    ZapFromSpace();
-  }
-
-  // Process pretenuring feedback and update allocation sites.
-  ProcessPretenuringFeedback();
-
-#ifdef VERIFY_HEAP
-  if (FLAG_verify_heap) {
-    Verify();
-  }
-#endif
-
-  AllowHeapAllocation for_the_rest_of_the_epilogue;
-
-#ifdef DEBUG
-  if (FLAG_print_global_handles) isolate_->global_handles()->Print();
-  if (FLAG_print_handles) PrintHandles();
-  if (FLAG_gc_verbose) Print();
-  if (FLAG_code_stats) ReportCodeStatistics("After GC");
-#endif
-  if (FLAG_deopt_every_n_garbage_collections > 0) {
-    // TODO(jkummerow/ulan/jarin): This is not safe! We can't assume that
-    // the topmost optimized frame can be deoptimized safely, because it
-    // might not have a lazy bailout point right after its current PC.
-    if (++gcs_since_last_deopt_ == FLAG_deopt_every_n_garbage_collections) {
-      Deoptimizer::DeoptimizeAll(isolate());
-      gcs_since_last_deopt_ = 0;
-    }
-  }
-
-  UpdateMaximumCommitted();
-
-  isolate_->counters()->alive_after_last_gc()->Set(
-      static_cast<int>(SizeOfObjects()));
-
-  isolate_->counters()->string_table_capacity()->Set(
-      string_table()->Capacity());
-  isolate_->counters()->number_of_symbols()->Set(
-      string_table()->NumberOfElements());
-
-  if (full_codegen_bytes_generated_ + crankshaft_codegen_bytes_generated_ > 0) {
-    isolate_->counters()->codegen_fraction_crankshaft()->AddSample(
-        static_cast<int>((crankshaft_codegen_bytes_generated_ * 100.0) /
-            (crankshaft_codegen_bytes_generated_
-            + full_codegen_bytes_generated_)));
-  }
-
-  if (CommittedMemory() > 0) {
-    isolate_->counters()->external_fragmentation_total()->AddSample(
-        static_cast<int>(100 - (SizeOfObjects() * 100.0) / CommittedMemory()));
-
-    isolate_->counters()->heap_fraction_new_space()->
-        AddSample(static_cast<int>(
-            (new_space()->CommittedMemory() * 100.0) / CommittedMemory()));
-    isolate_->counters()->heap_fraction_old_pointer_space()->AddSample(
-        static_cast<int>(
-            (old_pointer_space()->CommittedMemory() * 100.0) /
-            CommittedMemory()));
-    isolate_->counters()->heap_fraction_old_data_space()->AddSample(
-        static_cast<int>(
-            (old_data_space()->CommittedMemory() * 100.0) /
-            CommittedMemory()));
-    isolate_->counters()->heap_fraction_code_space()->
-        AddSample(static_cast<int>(
-            (code_space()->CommittedMemory() * 100.0) / CommittedMemory()));
-    isolate_->counters()->heap_fraction_map_space()->AddSample(
-        static_cast<int>(
-            (map_space()->CommittedMemory() * 100.0) / CommittedMemory()));
-    isolate_->counters()->heap_fraction_cell_space()->AddSample(
-        static_cast<int>(
-            (cell_space()->CommittedMemory() * 100.0) / CommittedMemory()));
-    isolate_->counters()->heap_fraction_property_cell_space()->
-        AddSample(static_cast<int>(
-            (property_cell_space()->CommittedMemory() * 100.0) /
-            CommittedMemory()));
-    isolate_->counters()->heap_fraction_lo_space()->
-        AddSample(static_cast<int>(
-            (lo_space()->CommittedMemory() * 100.0) / CommittedMemory()));
-
-    isolate_->counters()->heap_sample_total_committed()->AddSample(
-        static_cast<int>(CommittedMemory() / KB));
-    isolate_->counters()->heap_sample_total_used()->AddSample(
-        static_cast<int>(SizeOfObjects() / KB));
-    isolate_->counters()->heap_sample_map_space_committed()->AddSample(
-        static_cast<int>(map_space()->CommittedMemory() / KB));
-    isolate_->counters()->heap_sample_cell_space_committed()->AddSample(
-        static_cast<int>(cell_space()->CommittedMemory() / KB));
-    isolate_->counters()->
-        heap_sample_property_cell_space_committed()->
-            AddSample(static_cast<int>(
-                property_cell_space()->CommittedMemory() / KB));
-    isolate_->counters()->heap_sample_code_space_committed()->AddSample(
-        static_cast<int>(code_space()->CommittedMemory() / KB));
-
-    isolate_->counters()->heap_sample_maximum_committed()->AddSample(
-        static_cast<int>(MaximumCommittedMemory() / KB));
-  }
-
-#define UPDATE_COUNTERS_FOR_SPACE(space)                                       \
-  isolate_->counters()->space##_bytes_available()->Set(                        \
-      static_cast<int>(space()->Available()));                                 \
-  isolate_->counters()->space##_bytes_committed()->Set(                        \
-      static_cast<int>(space()->CommittedMemory()));                           \
-  isolate_->counters()->space##_bytes_used()->Set(                             \
-      static_cast<int>(space()->SizeOfObjects()));
-#define UPDATE_FRAGMENTATION_FOR_SPACE(space)                                  \
-  if (space()->CommittedMemory() > 0) {                                        \
-    isolate_->counters()->external_fragmentation_##space()->AddSample(         \
-        static_cast<int>(100 -                                                 \
-            (space()->SizeOfObjects() * 100.0) / space()->CommittedMemory())); \
-  }
-#define UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(space)                     \
-  UPDATE_COUNTERS_FOR_SPACE(space)                                             \
-  UPDATE_FRAGMENTATION_FOR_SPACE(space)
-
-  UPDATE_COUNTERS_FOR_SPACE(new_space)
-  UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(old_pointer_space)
-  UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(old_data_space)
-  UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(code_space)
-  UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(map_space)
-  UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(cell_space)
-  UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(property_cell_space)
-  UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(lo_space)
-#undef UPDATE_COUNTERS_FOR_SPACE
-#undef UPDATE_FRAGMENTATION_FOR_SPACE
-#undef UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE
-
-#ifdef DEBUG
-  ReportStatisticsAfterGC();
-#endif  // DEBUG
-
-  // Remember the last top pointer so that we can later find out
-  // whether we allocated in new space since the last GC.
-  new_space_top_after_last_gc_ = new_space()->top();
-}
-
-
-void Heap::CollectAllGarbage(int flags,
-                             const char* gc_reason,
-                             const v8::GCCallbackFlags gc_callback_flags) {
-  // Since we are ignoring the return value, the exact choice of space does
-  // not matter, so long as we do not specify NEW_SPACE, which would not
-  // cause a full GC.
-  mark_compact_collector_.SetFlags(flags);
-  CollectGarbage(OLD_POINTER_SPACE, gc_reason, gc_callback_flags);
-  mark_compact_collector_.SetFlags(kNoGCFlags);
-}
-
-
-void Heap::CollectAllAvailableGarbage(const char* gc_reason) {
-  // Since we are ignoring the return value, the exact choice of space does
-  // not matter, so long as we do not specify NEW_SPACE, which would not
-  // cause a full GC.
-  // Major GC would invoke weak handle callbacks on weakly reachable
-  // handles, but won't collect weakly reachable objects until next
-  // major GC.  Therefore if we collect aggressively and weak handle callback
-  // has been invoked, we rerun major GC to release objects which become
-  // garbage.
-  // Note: as weak callbacks can execute arbitrary code, we cannot
-  // hope that eventually there will be no weak callbacks invocations.
-  // Therefore stop recollecting after several attempts.
-  if (isolate()->concurrent_recompilation_enabled()) {
-    // The optimizing compiler may be unnecessarily holding on to memory.
-    DisallowHeapAllocation no_recursive_gc;
-    isolate()->optimizing_compiler_thread()->Flush();
-  }
-  mark_compact_collector()->SetFlags(kMakeHeapIterableMask |
-                                     kReduceMemoryFootprintMask);
-  isolate_->compilation_cache()->Clear();
-  const int kMaxNumberOfAttempts = 7;
-  const int kMinNumberOfAttempts = 2;
-  for (int attempt = 0; attempt < kMaxNumberOfAttempts; attempt++) {
-    if (!CollectGarbage(MARK_COMPACTOR, gc_reason, NULL) &&
-        attempt + 1 >= kMinNumberOfAttempts) {
-      break;
-    }
-  }
-  mark_compact_collector()->SetFlags(kNoGCFlags);
-  new_space_.Shrink();
-  UncommitFromSpace();
-  incremental_marking()->UncommitMarkingDeque();
-}
-
-
-void Heap::EnsureFillerObjectAtTop() {
-  // There may be an allocation memento behind every object in new space.
-  // If we evacuate a not full new space or if we are on the last page of
-  // the new space, then there may be uninitialized memory behind the top
-  // pointer of the new space page. We store a filler object there to
-  // identify the unused space.
-  Address from_top = new_space_.top();
-  Address from_limit = new_space_.limit();
-  if (from_top < from_limit) {
-    int remaining_in_page = static_cast<int>(from_limit - from_top);
-    CreateFillerObjectAt(from_top, remaining_in_page);
-  }
-}
-
-
-bool Heap::CollectGarbage(GarbageCollector collector,
-                          const char* gc_reason,
-                          const char* collector_reason,
-                          const v8::GCCallbackFlags gc_callback_flags) {
-  // The VM is in the GC state until exiting this function.
-  VMState<GC> state(isolate_);
-
-#ifdef DEBUG
-  // Reset the allocation timeout to the GC interval, but make sure to
-  // allow at least a few allocations after a collection. The reason
-  // for this is that we have a lot of allocation sequences and we
-  // assume that a garbage collection will allow the subsequent
-  // allocation attempts to go through.
-  allocation_timeout_ = Max(6, FLAG_gc_interval);
-#endif
-
-  EnsureFillerObjectAtTop();
-
-  if (collector == SCAVENGER && !incremental_marking()->IsStopped()) {
-    if (FLAG_trace_incremental_marking) {
-      PrintF("[IncrementalMarking] Scavenge during marking.\n");
-    }
-  }
-
-  if (collector == MARK_COMPACTOR &&
-      !mark_compact_collector()->abort_incremental_marking() &&
-      !incremental_marking()->IsStopped() &&
-      !incremental_marking()->should_hurry() &&
-      FLAG_incremental_marking_steps) {
-    // Make progress in incremental marking.
-    const intptr_t kStepSizeWhenDelayedByScavenge = 1 * MB;
-    incremental_marking()->Step(kStepSizeWhenDelayedByScavenge,
-                                IncrementalMarking::NO_GC_VIA_STACK_GUARD);
-    if (!incremental_marking()->IsComplete() && !FLAG_gc_global) {
-      if (FLAG_trace_incremental_marking) {
-        PrintF("[IncrementalMarking] Delaying MarkSweep.\n");
-      }
-      collector = SCAVENGER;
-      collector_reason = "incremental marking delaying mark-sweep";
-    }
-  }
-
-  bool next_gc_likely_to_collect_more = false;
-
-  {
-    tracer()->Start(collector, gc_reason, collector_reason);
-    DCHECK(AllowHeapAllocation::IsAllowed());
-    DisallowHeapAllocation no_allocation_during_gc;
-    GarbageCollectionPrologue();
-
-    {
-      HistogramTimerScope histogram_timer_scope(
-          (collector == SCAVENGER) ? isolate_->counters()->gc_scavenger()
-                                   : isolate_->counters()->gc_compactor());
-      next_gc_likely_to_collect_more =
-          PerformGarbageCollection(collector, gc_callback_flags);
-    }
-
-    GarbageCollectionEpilogue();
-    tracer()->Stop();
-  }
-
-  // Start incremental marking for the next cycle. The heap snapshot
-  // generator needs incremental marking to stay off after it aborted.
-  if (!mark_compact_collector()->abort_incremental_marking() &&
-      incremental_marking()->IsStopped() &&
-      incremental_marking()->WorthActivating() &&
-      NextGCIsLikelyToBeFull()) {
-    incremental_marking()->Start();
-  }
-
-  return next_gc_likely_to_collect_more;
-}
-
-
-int Heap::NotifyContextDisposed() {
-  if (isolate()->concurrent_recompilation_enabled()) {
-    // Flush the queued recompilation tasks.
-    isolate()->optimizing_compiler_thread()->Flush();
-  }
-  flush_monomorphic_ics_ = true;
-  AgeInlineCaches();
-  return ++contexts_disposed_;
-}
-
-
-void Heap::MoveElements(FixedArray* array,
-                        int dst_index,
-                        int src_index,
-                        int len) {
-  if (len == 0) return;
-
-  DCHECK(array->map() != fixed_cow_array_map());
-  Object** dst_objects = array->data_start() + dst_index;
-  MemMove(dst_objects, array->data_start() + src_index, len * kPointerSize);
-  if (!InNewSpace(array)) {
-    for (int i = 0; i < len; i++) {
-      // TODO(hpayer): check store buffer for entries
-      if (InNewSpace(dst_objects[i])) {
-        RecordWrite(array->address(), array->OffsetOfElementAt(dst_index + i));
-      }
-    }
-  }
-  incremental_marking()->RecordWrites(array);
-}
-
-
-#ifdef VERIFY_HEAP
-// Helper class for verifying the string table.
-class StringTableVerifier : public ObjectVisitor {
- public:
-  void VisitPointers(Object** start, Object** end) {
-    // Visit all HeapObject pointers in [start, end).
-    for (Object** p = start; p < end; p++) {
-      if ((*p)->IsHeapObject()) {
-        // Check that the string is actually internalized.
-        CHECK((*p)->IsTheHole() || (*p)->IsUndefined() ||
-              (*p)->IsInternalizedString());
-      }
-    }
-  }
-};
-
-
-static void VerifyStringTable(Heap* heap) {
-  StringTableVerifier verifier;
-  heap->string_table()->IterateElements(&verifier);
-}
-#endif  // VERIFY_HEAP
-
-
-static bool AbortIncrementalMarkingAndCollectGarbage(
-    Heap* heap,
-    AllocationSpace space,
-    const char* gc_reason = NULL) {
-  heap->mark_compact_collector()->SetFlags(Heap::kAbortIncrementalMarkingMask);
-  bool result = heap->CollectGarbage(space, gc_reason);
-  heap->mark_compact_collector()->SetFlags(Heap::kNoGCFlags);
-  return result;
-}
-
-
-void Heap::ReserveSpace(int *sizes, Address *locations_out) {
-  bool gc_performed = true;
-  int counter = 0;
-  static const int kThreshold = 20;
-  while (gc_performed && counter++ < kThreshold) {
-    gc_performed = false;
-    DCHECK(NEW_SPACE == FIRST_PAGED_SPACE - 1);
-    for (int space = NEW_SPACE; space <= LAST_PAGED_SPACE; space++) {
-      if (sizes[space] != 0) {
-        AllocationResult allocation;
-        if (space == NEW_SPACE) {
-          allocation = new_space()->AllocateRaw(sizes[space]);
-        } else {
-          allocation = paged_space(space)->AllocateRaw(sizes[space]);
-        }
-        FreeListNode* node;
-        if (!allocation.To(&node)) {
-          if (space == NEW_SPACE) {
-            Heap::CollectGarbage(NEW_SPACE,
-                                 "failed to reserve space in the new space");
-          } else {
-            AbortIncrementalMarkingAndCollectGarbage(
-                this,
-                static_cast<AllocationSpace>(space),
-                "failed to reserve space in paged space");
-          }
-          gc_performed = true;
-          break;
-        } else {
-          // Mark with a free list node, in case we have a GC before
-          // deserializing.
-          node->set_size(this, sizes[space]);
-          locations_out[space] = node->address();
-        }
-      }
-    }
-  }
-
-  if (gc_performed) {
-    // Failed to reserve the space after several attempts.
-    V8::FatalProcessOutOfMemory("Heap::ReserveSpace");
-  }
-}
-
-
-void Heap::EnsureFromSpaceIsCommitted() {
-  if (new_space_.CommitFromSpaceIfNeeded()) return;
-
-  // Committing memory to from space failed.
-  // Memory is exhausted and we will die.
-  V8::FatalProcessOutOfMemory("Committing semi space failed.");
-}
-
-
-void Heap::ClearJSFunctionResultCaches() {
-  if (isolate_->bootstrapper()->IsActive()) return;
-
-  Object* context = native_contexts_list();
-  while (!context->IsUndefined()) {
-    // Get the caches for this context. GC can happen when the context
-    // is not fully initialized, so the caches can be undefined.
-    Object* caches_or_undefined =
-        Context::cast(context)->get(Context::JSFUNCTION_RESULT_CACHES_INDEX);
-    if (!caches_or_undefined->IsUndefined()) {
-      FixedArray* caches = FixedArray::cast(caches_or_undefined);
-      // Clear the caches:
-      int length = caches->length();
-      for (int i = 0; i < length; i++) {
-        JSFunctionResultCache::cast(caches->get(i))->Clear();
-      }
-    }
-    // Get the next context:
-    context = Context::cast(context)->get(Context::NEXT_CONTEXT_LINK);
-  }
-}
-
-
-void Heap::ClearNormalizedMapCaches() {
-  if (isolate_->bootstrapper()->IsActive() &&
-      !incremental_marking()->IsMarking()) {
-    return;
-  }
-
-  Object* context = native_contexts_list();
-  while (!context->IsUndefined()) {
-    // GC can happen when the context is not fully initialized,
-    // so the cache can be undefined.
-    Object* cache =
-        Context::cast(context)->get(Context::NORMALIZED_MAP_CACHE_INDEX);
-    if (!cache->IsUndefined()) {
-      NormalizedMapCache::cast(cache)->Clear();
-    }
-    context = Context::cast(context)->get(Context::NEXT_CONTEXT_LINK);
-  }
-}
-
-
-void Heap::UpdateSurvivalStatistics(int start_new_space_size) {
-  if (start_new_space_size == 0) return;
-
-  promotion_rate_ =
-        (static_cast<double>(promoted_objects_size_) /
-            static_cast<double>(start_new_space_size) * 100);
-
-  semi_space_copied_rate_ =
-        (static_cast<double>(semi_space_copied_object_size_) /
-            static_cast<double>(start_new_space_size) * 100);
-
-  double survival_rate = promotion_rate_ + semi_space_copied_rate_;
-
-  if (survival_rate > kYoungSurvivalRateHighThreshold) {
-    high_survival_rate_period_length_++;
-  } else {
-    high_survival_rate_period_length_ = 0;
-  }
-}
-
-bool Heap::PerformGarbageCollection(
-    GarbageCollector collector,
-    const v8::GCCallbackFlags gc_callback_flags) {
-  int freed_global_handles = 0;
-
-  if (collector != SCAVENGER) {
-    PROFILE(isolate_, CodeMovingGCEvent());
-  }
-
-#ifdef VERIFY_HEAP
-  if (FLAG_verify_heap) {
-    VerifyStringTable(this);
-  }
-#endif
-
-  GCType gc_type =
-      collector == MARK_COMPACTOR ? kGCTypeMarkSweepCompact : kGCTypeScavenge;
-
-  { GCCallbacksScope scope(this);
-    if (scope.CheckReenter()) {
-      AllowHeapAllocation allow_allocation;
-      GCTracer::Scope scope(tracer(), GCTracer::Scope::EXTERNAL);
-      VMState<EXTERNAL> state(isolate_);
-      HandleScope handle_scope(isolate_);
-      CallGCPrologueCallbacks(gc_type, kNoGCCallbackFlags);
-    }
-  }
-
-  EnsureFromSpaceIsCommitted();
-
-  int start_new_space_size = Heap::new_space()->SizeAsInt();
-
-  if (IsHighSurvivalRate()) {
-    // We speed up the incremental marker if it is running so that it
-    // does not fall behind the rate of promotion, which would cause a
-    // constantly growing old space.
-    incremental_marking()->NotifyOfHighPromotionRate();
-  }
-
-  if (collector == MARK_COMPACTOR) {
-    // Perform mark-sweep with optional compaction.
-    MarkCompact();
-    sweep_generation_++;
-    // Temporarily set the limit for case when PostGarbageCollectionProcessing
-    // allocates and triggers GC. The real limit is set at after
-    // PostGarbageCollectionProcessing.
-    old_generation_allocation_limit_ =
-        OldGenerationAllocationLimit(PromotedSpaceSizeOfObjects(), 0);
-    old_gen_exhausted_ = false;
-  } else {
-    Scavenge();
-  }
-
-  UpdateSurvivalStatistics(start_new_space_size);
-
-  isolate_->counters()->objs_since_last_young()->Set(0);
-
-  // Callbacks that fire after this point might trigger nested GCs and
-  // restart incremental marking, the assertion can't be moved down.
-  DCHECK(collector == SCAVENGER || incremental_marking()->IsStopped());
-
-  gc_post_processing_depth_++;
-  { AllowHeapAllocation allow_allocation;
-    GCTracer::Scope scope(tracer(), GCTracer::Scope::EXTERNAL);
-    freed_global_handles =
-        isolate_->global_handles()->PostGarbageCollectionProcessing(collector);
-  }
-  gc_post_processing_depth_--;
-
-  isolate_->eternal_handles()->PostGarbageCollectionProcessing(this);
-
-  // Update relocatables.
-  Relocatable::PostGarbageCollectionProcessing(isolate_);
-
-  if (collector == MARK_COMPACTOR) {
-    // Register the amount of external allocated memory.
-    amount_of_external_allocated_memory_at_last_global_gc_ =
-        amount_of_external_allocated_memory_;
-    old_generation_allocation_limit_ =
-        OldGenerationAllocationLimit(PromotedSpaceSizeOfObjects(),
-                                     freed_global_handles);
-  }
-
-  { GCCallbacksScope scope(this);
-    if (scope.CheckReenter()) {
-      AllowHeapAllocation allow_allocation;
-      GCTracer::Scope scope(tracer(), GCTracer::Scope::EXTERNAL);
-      VMState<EXTERNAL> state(isolate_);
-      HandleScope handle_scope(isolate_);
-      CallGCEpilogueCallbacks(gc_type, gc_callback_flags);
-    }
-  }
-
-#ifdef VERIFY_HEAP
-  if (FLAG_verify_heap) {
-    VerifyStringTable(this);
-  }
-#endif
-
-  return freed_global_handles > 0;
-}
-
-
-void Heap::CallGCPrologueCallbacks(GCType gc_type, GCCallbackFlags flags) {
-  for (int i = 0; i < gc_prologue_callbacks_.length(); ++i) {
-    if (gc_type & gc_prologue_callbacks_[i].gc_type) {
-      if (!gc_prologue_callbacks_[i].pass_isolate_) {
-        v8::GCPrologueCallback callback =
-            reinterpret_cast<v8::GCPrologueCallback>(
-                gc_prologue_callbacks_[i].callback);
-        callback(gc_type, flags);
-      } else {
-        v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(this->isolate());
-        gc_prologue_callbacks_[i].callback(isolate, gc_type, flags);
-      }
-    }
-  }
-}
-
-
-void Heap::CallGCEpilogueCallbacks(GCType gc_type,
-                                   GCCallbackFlags gc_callback_flags) {
-  for (int i = 0; i < gc_epilogue_callbacks_.length(); ++i) {
-    if (gc_type & gc_epilogue_callbacks_[i].gc_type) {
-      if (!gc_epilogue_callbacks_[i].pass_isolate_) {
-        v8::GCPrologueCallback callback =
-            reinterpret_cast<v8::GCPrologueCallback>(
-                gc_epilogue_callbacks_[i].callback);
-        callback(gc_type, gc_callback_flags);
-      } else {
-        v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(this->isolate());
-        gc_epilogue_callbacks_[i].callback(
-            isolate, gc_type, gc_callback_flags);
-      }
-    }
-  }
-}
-
-
-void Heap::MarkCompact() {
-  gc_state_ = MARK_COMPACT;
-  LOG(isolate_, ResourceEvent("markcompact", "begin"));
-
-  uint64_t size_of_objects_before_gc = SizeOfObjects();
-
-  mark_compact_collector_.Prepare();
-
-  ms_count_++;
-
-  MarkCompactPrologue();
-
-  mark_compact_collector_.CollectGarbage();
-
-  LOG(isolate_, ResourceEvent("markcompact", "end"));
-
-  gc_state_ = NOT_IN_GC;
-
-  isolate_->counters()->objs_since_last_full()->Set(0);
-
-  flush_monomorphic_ics_ = false;
-
-  if (FLAG_allocation_site_pretenuring) {
-    EvaluateOldSpaceLocalPretenuring(size_of_objects_before_gc);
-  }
-}
-
-
-void Heap::MarkCompactPrologue() {
-  // At any old GC clear the keyed lookup cache to enable collection of unused
-  // maps.
-  isolate_->keyed_lookup_cache()->Clear();
-  isolate_->context_slot_cache()->Clear();
-  isolate_->descriptor_lookup_cache()->Clear();
-  RegExpResultsCache::Clear(string_split_cache());
-  RegExpResultsCache::Clear(regexp_multiple_cache());
-
-  isolate_->compilation_cache()->MarkCompactPrologue();
-
-  CompletelyClearInstanceofCache();
-
-  FlushNumberStringCache();
-  if (FLAG_cleanup_code_caches_at_gc) {
-    polymorphic_code_cache()->set_cache(undefined_value());
-  }
-
-  ClearNormalizedMapCaches();
-}
-
-
-// Helper class for copying HeapObjects
-class ScavengeVisitor: public ObjectVisitor {
- public:
-  explicit ScavengeVisitor(Heap* heap) : heap_(heap) {}
-
-  void VisitPointer(Object** p) { ScavengePointer(p); }
-
-  void VisitPointers(Object** start, Object** end) {
-    // Copy all HeapObject pointers in [start, end)
-    for (Object** p = start; p < end; p++) ScavengePointer(p);
-  }
-
- private:
-  void ScavengePointer(Object** p) {
-    Object* object = *p;
-    if (!heap_->InNewSpace(object)) return;
-    Heap::ScavengeObject(reinterpret_cast<HeapObject**>(p),
-                         reinterpret_cast<HeapObject*>(object));
-  }
-
-  Heap* heap_;
-};
-
-
-#ifdef VERIFY_HEAP
-// Visitor class to verify pointers in code or data space do not point into
-// new space.
-class VerifyNonPointerSpacePointersVisitor: public ObjectVisitor {
- public:
-  explicit VerifyNonPointerSpacePointersVisitor(Heap* heap) : heap_(heap) {}
-  void VisitPointers(Object** start, Object**end) {
-    for (Object** current = start; current < end; current++) {
-      if ((*current)->IsHeapObject()) {
-        CHECK(!heap_->InNewSpace(HeapObject::cast(*current)));
-      }
-    }
-  }
-
- private:
-  Heap* heap_;
-};
-
-
-static void VerifyNonPointerSpacePointers(Heap* heap) {
-  // Verify that there are no pointers to new space in spaces where we
-  // do not expect them.
-  VerifyNonPointerSpacePointersVisitor v(heap);
-  HeapObjectIterator code_it(heap->code_space());
-  for (HeapObject* object = code_it.Next();
-       object != NULL; object = code_it.Next())
-    object->Iterate(&v);
-
-  // The old data space was normally swept conservatively so that the iterator
-  // doesn't work, so we normally skip the next bit.
-  if (heap->old_data_space()->swept_precisely()) {
-    HeapObjectIterator data_it(heap->old_data_space());
-    for (HeapObject* object = data_it.Next();
-         object != NULL; object = data_it.Next())
-      object->Iterate(&v);
-  }
-}
-#endif  // VERIFY_HEAP
-
-
-void Heap::CheckNewSpaceExpansionCriteria() {
-  if (new_space_.Capacity() < new_space_.MaximumCapacity() &&
-      survived_since_last_expansion_ > new_space_.Capacity()) {
-    // Grow the size of new space if there is room to grow, enough data
-    // has survived scavenge since the last expansion and we are not in
-    // high promotion mode.
-    new_space_.Grow();
-    survived_since_last_expansion_ = 0;
-  }
-}
-
-
-static bool IsUnscavengedHeapObject(Heap* heap, Object** p) {
-  return heap->InNewSpace(*p) &&
-      !HeapObject::cast(*p)->map_word().IsForwardingAddress();
-}
-
-
-void Heap::ScavengeStoreBufferCallback(
-    Heap* heap,
-    MemoryChunk* page,
-    StoreBufferEvent event) {
-  heap->store_buffer_rebuilder_.Callback(page, event);
-}
-
-
-void StoreBufferRebuilder::Callback(MemoryChunk* page, StoreBufferEvent event) {
-  if (event == kStoreBufferStartScanningPagesEvent) {
-    start_of_current_page_ = NULL;
-    current_page_ = NULL;
-  } else if (event == kStoreBufferScanningPageEvent) {
-    if (current_page_ != NULL) {
-      // If this page already overflowed the store buffer during this iteration.
-      if (current_page_->scan_on_scavenge()) {
-        // Then we should wipe out the entries that have been added for it.
-        store_buffer_->SetTop(start_of_current_page_);
-      } else if (store_buffer_->Top() - start_of_current_page_ >=
-                 (store_buffer_->Limit() - store_buffer_->Top()) >> 2) {
-        // Did we find too many pointers in the previous page?  The heuristic is
-        // that no page can take more then 1/5 the remaining slots in the store
-        // buffer.
-        current_page_->set_scan_on_scavenge(true);
-        store_buffer_->SetTop(start_of_current_page_);
-      } else {
-        // In this case the page we scanned took a reasonable number of slots in
-        // the store buffer.  It has now been rehabilitated and is no longer
-        // marked scan_on_scavenge.
-        DCHECK(!current_page_->scan_on_scavenge());
-      }
-    }
-    start_of_current_page_ = store_buffer_->Top();
-    current_page_ = page;
-  } else if (event == kStoreBufferFullEvent) {
-    // The current page overflowed the store buffer again.  Wipe out its entries
-    // in the store buffer and mark it scan-on-scavenge again.  This may happen
-    // several times while scanning.
-    if (current_page_ == NULL) {
-      // Store Buffer overflowed while scanning promoted objects.  These are not
-      // in any particular page, though they are likely to be clustered by the
-      // allocation routines.
-      store_buffer_->EnsureSpace(StoreBuffer::kStoreBufferSize / 2);
-    } else {
-      // Store Buffer overflowed while scanning a particular old space page for
-      // pointers to new space.
-      DCHECK(current_page_ == page);
-      DCHECK(page != NULL);
-      current_page_->set_scan_on_scavenge(true);
-      DCHECK(start_of_current_page_ != store_buffer_->Top());
-      store_buffer_->SetTop(start_of_current_page_);
-    }
-  } else {
-    UNREACHABLE();
-  }
-}
-
-
-void PromotionQueue::Initialize() {
-  // Assumes that a NewSpacePage exactly fits a number of promotion queue
-  // entries (where each is a pair of intptr_t). This allows us to simplify
-  // the test fpr when to switch pages.
-  DCHECK((Page::kPageSize - MemoryChunk::kBodyOffset) % (2 * kPointerSize)
-         == 0);
-  limit_ = reinterpret_cast<intptr_t*>(heap_->new_space()->ToSpaceStart());
-  front_ = rear_ =
-      reinterpret_cast<intptr_t*>(heap_->new_space()->ToSpaceEnd());
-  emergency_stack_ = NULL;
-  guard_ = false;
-}
-
-
-void PromotionQueue::RelocateQueueHead() {
-  DCHECK(emergency_stack_ == NULL);
-
-  Page* p = Page::FromAllocationTop(reinterpret_cast<Address>(rear_));
-  intptr_t* head_start = rear_;
-  intptr_t* head_end =
-      Min(front_, reinterpret_cast<intptr_t*>(p->area_end()));
-
-  int entries_count =
-      static_cast<int>(head_end - head_start) / kEntrySizeInWords;
-
-  emergency_stack_ = new List<Entry>(2 * entries_count);
-
-  while (head_start != head_end) {
-    int size = static_cast<int>(*(head_start++));
-    HeapObject* obj = reinterpret_cast<HeapObject*>(*(head_start++));
-    emergency_stack_->Add(Entry(obj, size));
-  }
-  rear_ = head_end;
-}
-
-
-class ScavengeWeakObjectRetainer : public WeakObjectRetainer {
- public:
-  explicit ScavengeWeakObjectRetainer(Heap* heap) : heap_(heap) { }
-
-  virtual Object* RetainAs(Object* object) {
-    if (!heap_->InFromSpace(object)) {
-      return object;
-    }
-
-    MapWord map_word = HeapObject::cast(object)->map_word();
-    if (map_word.IsForwardingAddress()) {
-      return map_word.ToForwardingAddress();
-    }
-    return NULL;
-  }
-
- private:
-  Heap* heap_;
-};
-
-
-void Heap::Scavenge() {
-  RelocationLock relocation_lock(this);
-
-#ifdef VERIFY_HEAP
-  if (FLAG_verify_heap) VerifyNonPointerSpacePointers(this);
-#endif
-
-  gc_state_ = SCAVENGE;
-
-  // Implements Cheney's copying algorithm
-  LOG(isolate_, ResourceEvent("scavenge", "begin"));
-
-  // Clear descriptor cache.
-  isolate_->descriptor_lookup_cache()->Clear();
-
-  // Used for updating survived_since_last_expansion_ at function end.
-  intptr_t survived_watermark = PromotedSpaceSizeOfObjects();
-
-  SelectScavengingVisitorsTable();
-
-  incremental_marking()->PrepareForScavenge();
-
-  // Flip the semispaces.  After flipping, to space is empty, from space has
-  // live objects.
-  new_space_.Flip();
-  new_space_.ResetAllocationInfo();
-
-  // We need to sweep newly copied objects which can be either in the
-  // to space or promoted to the old generation.  For to-space
-  // objects, we treat the bottom of the to space as a queue.  Newly
-  // copied and unswept objects lie between a 'front' mark and the
-  // allocation pointer.
-  //
-  // Promoted objects can go into various old-generation spaces, and
-  // can be allocated internally in the spaces (from the free list).
-  // We treat the top of the to space as a queue of addresses of
-  // promoted objects.  The addresses of newly promoted and unswept
-  // objects lie between a 'front' mark and a 'rear' mark that is
-  // updated as a side effect of promoting an object.
-  //
-  // There is guaranteed to be enough room at the top of the to space
-  // for the addresses of promoted objects: every object promoted
-  // frees up its size in bytes from the top of the new space, and
-  // objects are at least one pointer in size.
-  Address new_space_front = new_space_.ToSpaceStart();
-  promotion_queue_.Initialize();
-
-#ifdef DEBUG
-  store_buffer()->Clean();
-#endif
-
-  ScavengeVisitor scavenge_visitor(this);
-  // Copy roots.
-  IterateRoots(&scavenge_visitor, VISIT_ALL_IN_SCAVENGE);
-
-  // Copy objects reachable from the old generation.
-  {
-    StoreBufferRebuildScope scope(this,
-                                  store_buffer(),
-                                  &ScavengeStoreBufferCallback);
-    store_buffer()->IteratePointersToNewSpace(&ScavengeObject);
-  }
-
-  // Copy objects reachable from simple cells by scavenging cell values
-  // directly.
-  HeapObjectIterator cell_iterator(cell_space_);
-  for (HeapObject* heap_object = cell_iterator.Next();
-       heap_object != NULL;
-       heap_object = cell_iterator.Next()) {
-    if (heap_object->IsCell()) {
-      Cell* cell = Cell::cast(heap_object);
-      Address value_address = cell->ValueAddress();
-      scavenge_visitor.VisitPointer(reinterpret_cast<Object**>(value_address));
-    }
-  }
-
-  // Copy objects reachable from global property cells by scavenging global
-  // property cell values directly.
-  HeapObjectIterator js_global_property_cell_iterator(property_cell_space_);
-  for (HeapObject* heap_object = js_global_property_cell_iterator.Next();
-       heap_object != NULL;
-       heap_object = js_global_property_cell_iterator.Next()) {
-    if (heap_object->IsPropertyCell()) {
-      PropertyCell* cell = PropertyCell::cast(heap_object);
-      Address value_address = cell->ValueAddress();
-      scavenge_visitor.VisitPointer(reinterpret_cast<Object**>(value_address));
-      Address type_address = cell->TypeAddress();
-      scavenge_visitor.VisitPointer(reinterpret_cast<Object**>(type_address));
-    }
-  }
-
-  // Copy objects reachable from the encountered weak collections list.
-  scavenge_visitor.VisitPointer(&encountered_weak_collections_);
-
-  // Copy objects reachable from the code flushing candidates list.
-  MarkCompactCollector* collector = mark_compact_collector();
-  if (collector->is_code_flushing_enabled()) {
-    collector->code_flusher()->IteratePointersToFromSpace(&scavenge_visitor);
-  }
-
-  new_space_front = DoScavenge(&scavenge_visitor, new_space_front);
-
-  while (isolate()->global_handles()->IterateObjectGroups(
-      &scavenge_visitor, &IsUnscavengedHeapObject)) {
-    new_space_front = DoScavenge(&scavenge_visitor, new_space_front);
-  }
-  isolate()->global_handles()->RemoveObjectGroups();
-  isolate()->global_handles()->RemoveImplicitRefGroups();
-
-  isolate_->global_handles()->IdentifyNewSpaceWeakIndependentHandles(
-      &IsUnscavengedHeapObject);
-  isolate_->global_handles()->IterateNewSpaceWeakIndependentRoots(
-      &scavenge_visitor);
-  new_space_front = DoScavenge(&scavenge_visitor, new_space_front);
-
-  UpdateNewSpaceReferencesInExternalStringTable(
-      &UpdateNewSpaceReferenceInExternalStringTableEntry);
-
-  promotion_queue_.Destroy();
-
-  incremental_marking()->UpdateMarkingDequeAfterScavenge();
-
-  ScavengeWeakObjectRetainer weak_object_retainer(this);
-  ProcessWeakReferences(&weak_object_retainer);
-
-  DCHECK(new_space_front == new_space_.top());
-
-  // Set age mark.
-  new_space_.set_age_mark(new_space_.top());
-
-  new_space_.LowerInlineAllocationLimit(
-      new_space_.inline_allocation_limit_step());
-
-  // Update how much has survived scavenge.
-  IncrementYoungSurvivorsCounter(static_cast<int>(
-      (PromotedSpaceSizeOfObjects() - survived_watermark) + new_space_.Size()));
-
-  LOG(isolate_, ResourceEvent("scavenge", "end"));
-
-  gc_state_ = NOT_IN_GC;
-
-  scavenges_since_last_idle_round_++;
-}
-
-
-String* Heap::UpdateNewSpaceReferenceInExternalStringTableEntry(Heap* heap,
-                                                                Object** p) {
-  MapWord first_word = HeapObject::cast(*p)->map_word();
-
-  if (!first_word.IsForwardingAddress()) {
-    // Unreachable external string can be finalized.
-    heap->FinalizeExternalString(String::cast(*p));
-    return NULL;
-  }
-
-  // String is still reachable.
-  return String::cast(first_word.ToForwardingAddress());
-}
-
-
-void Heap::UpdateNewSpaceReferencesInExternalStringTable(
-    ExternalStringTableUpdaterCallback updater_func) {
-#ifdef VERIFY_HEAP
-  if (FLAG_verify_heap) {
-    external_string_table_.Verify();
-  }
-#endif
-
-  if (external_string_table_.new_space_strings_.is_empty()) return;
-
-  Object** start = &external_string_table_.new_space_strings_[0];
-  Object** end = start + external_string_table_.new_space_strings_.length();
-  Object** last = start;
-
-  for (Object** p = start; p < end; ++p) {
-    DCHECK(InFromSpace(*p));
-    String* target = updater_func(this, p);
-
-    if (target == NULL) continue;
-
-    DCHECK(target->IsExternalString());
-
-    if (InNewSpace(target)) {
-      // String is still in new space.  Update the table entry.
-      *last = target;
-      ++last;
-    } else {
-      // String got promoted.  Move it to the old string list.
-      external_string_table_.AddOldString(target);
-    }
-  }
-
-  DCHECK(last <= end);
-  external_string_table_.ShrinkNewStrings(static_cast<int>(last - start));
-}
-
-
-void Heap::UpdateReferencesInExternalStringTable(
-    ExternalStringTableUpdaterCallback updater_func) {
-
-  // Update old space string references.
-  if (external_string_table_.old_space_strings_.length() > 0) {
-    Object** start = &external_string_table_.old_space_strings_[0];
-    Object** end = start + external_string_table_.old_space_strings_.length();
-    for (Object** p = start; p < end; ++p) *p = updater_func(this, p);
-  }
-
-  UpdateNewSpaceReferencesInExternalStringTable(updater_func);
-}
-
-
-void Heap::ProcessWeakReferences(WeakObjectRetainer* retainer) {
-  ProcessArrayBuffers(retainer);
-  ProcessNativeContexts(retainer);
-  // TODO(mvstanton): AllocationSites only need to be processed during
-  // MARK_COMPACT, as they live in old space. Verify and address.
-  ProcessAllocationSites(retainer);
-}
-
-
-void Heap::ProcessNativeContexts(WeakObjectRetainer* retainer) {
-  Object* head = VisitWeakList<Context>(this, native_contexts_list(), retainer);
-  // Update the head of the list of contexts.
-  set_native_contexts_list(head);
-}
-
-
-void Heap::ProcessArrayBuffers(WeakObjectRetainer* retainer) {
-  Object* array_buffer_obj =
-      VisitWeakList<JSArrayBuffer>(this, array_buffers_list(), retainer);
-  set_array_buffers_list(array_buffer_obj);
-}
-
-
-void Heap::TearDownArrayBuffers() {
-  Object* undefined = undefined_value();
-  for (Object* o = array_buffers_list(); o != undefined;) {
-    JSArrayBuffer* buffer = JSArrayBuffer::cast(o);
-    Runtime::FreeArrayBuffer(isolate(), buffer);
-    o = buffer->weak_next();
-  }
-  set_array_buffers_list(undefined);
-}
-
-
-void Heap::ProcessAllocationSites(WeakObjectRetainer* retainer) {
-  Object* allocation_site_obj =
-      VisitWeakList<AllocationSite>(this, allocation_sites_list(), retainer);
-  set_allocation_sites_list(allocation_site_obj);
-}
-
-
-void Heap::ResetAllAllocationSitesDependentCode(PretenureFlag flag) {
-  DisallowHeapAllocation no_allocation_scope;
-  Object* cur = allocation_sites_list();
-  bool marked = false;
-  while (cur->IsAllocationSite()) {
-    AllocationSite* casted = AllocationSite::cast(cur);
-    if (casted->GetPretenureMode() == flag) {
-      casted->ResetPretenureDecision();
-      casted->set_deopt_dependent_code(true);
-      marked = true;
-    }
-    cur = casted->weak_next();
-  }
-  if (marked) isolate_->stack_guard()->RequestDeoptMarkedAllocationSites();
-}
-
-
-void Heap::EvaluateOldSpaceLocalPretenuring(
-    uint64_t size_of_objects_before_gc) {
-  uint64_t size_of_objects_after_gc = SizeOfObjects();
-  double old_generation_survival_rate =
-      (static_cast<double>(size_of_objects_after_gc) * 100) /
-          static_cast<double>(size_of_objects_before_gc);
-
-  if (old_generation_survival_rate < kOldSurvivalRateLowThreshold) {
-    // Too many objects died in the old generation, pretenuring of wrong
-    // allocation sites may be the cause for that. We have to deopt all
-    // dependent code registered in the allocation sites to re-evaluate
-    // our pretenuring decisions.
-    ResetAllAllocationSitesDependentCode(TENURED);
-    if (FLAG_trace_pretenuring) {
-      PrintF("Deopt all allocation sites dependent code due to low survival "
-             "rate in the old generation %f\n", old_generation_survival_rate);
-    }
-  }
-}
-
-
-void Heap::VisitExternalResources(v8::ExternalResourceVisitor* visitor) {
-  DisallowHeapAllocation no_allocation;
-  // All external strings are listed in the external string table.
-
-  class ExternalStringTableVisitorAdapter : public ObjectVisitor {
-   public:
-    explicit ExternalStringTableVisitorAdapter(
-        v8::ExternalResourceVisitor* visitor) : visitor_(visitor) {}
-    virtual void VisitPointers(Object** start, Object** end) {
-      for (Object** p = start; p < end; p++) {
-        DCHECK((*p)->IsExternalString());
-        visitor_->VisitExternalString(Utils::ToLocal(
-            Handle<String>(String::cast(*p))));
-      }
-    }
-   private:
-    v8::ExternalResourceVisitor* visitor_;
-  } external_string_table_visitor(visitor);
-
-  external_string_table_.Iterate(&external_string_table_visitor);
-}
-
-
-class NewSpaceScavenger : public StaticNewSpaceVisitor<NewSpaceScavenger> {
- public:
-  static inline void VisitPointer(Heap* heap, Object** p) {
-    Object* object = *p;
-    if (!heap->InNewSpace(object)) return;
-    Heap::ScavengeObject(reinterpret_cast<HeapObject**>(p),
-                         reinterpret_cast<HeapObject*>(object));
-  }
-};
-
-
-Address Heap::DoScavenge(ObjectVisitor* scavenge_visitor,
-                         Address new_space_front) {
-  do {
-    SemiSpace::AssertValidRange(new_space_front, new_space_.top());
-    // The addresses new_space_front and new_space_.top() define a
-    // queue of unprocessed copied objects.  Process them until the
-    // queue is empty.
-    while (new_space_front != new_space_.top()) {
-      if (!NewSpacePage::IsAtEnd(new_space_front)) {
-        HeapObject* object = HeapObject::FromAddress(new_space_front);
-        new_space_front +=
-          NewSpaceScavenger::IterateBody(object->map(), object);
-      } else {
-        new_space_front =
-            NewSpacePage::FromLimit(new_space_front)->next_page()->area_start();
-      }
-    }
-
-    // Promote and process all the to-be-promoted objects.
-    {
-      StoreBufferRebuildScope scope(this,
-                                    store_buffer(),
-                                    &ScavengeStoreBufferCallback);
-      while (!promotion_queue()->is_empty()) {
-        HeapObject* target;
-        int size;
-        promotion_queue()->remove(&target, &size);
-
-        // Promoted object might be already partially visited
-        // during old space pointer iteration. Thus we search specificly
-        // for pointers to from semispace instead of looking for pointers
-        // to new space.
-        DCHECK(!target->IsMap());
-        IterateAndMarkPointersToFromSpace(target->address(),
-                                          target->address() + size,
-                                          &ScavengeObject);
-      }
-    }
-
-    // Take another spin if there are now unswept objects in new space
-    // (there are currently no more unswept promoted objects).
-  } while (new_space_front != new_space_.top());
-
-  return new_space_front;
-}
-
-
-STATIC_ASSERT((FixedDoubleArray::kHeaderSize &
-               kDoubleAlignmentMask) == 0);  // NOLINT
-STATIC_ASSERT((ConstantPoolArray::kFirstEntryOffset &
-               kDoubleAlignmentMask) == 0);  // NOLINT
-STATIC_ASSERT((ConstantPoolArray::kExtendedFirstOffset &
-               kDoubleAlignmentMask) == 0);  // NOLINT
-
-
-INLINE(static HeapObject* EnsureDoubleAligned(Heap* heap,
-                                              HeapObject* object,
-                                              int size));
-
-static HeapObject* EnsureDoubleAligned(Heap* heap,
-                                       HeapObject* object,
-                                       int size) {
-  if ((OffsetFrom(object->address()) & kDoubleAlignmentMask) != 0) {
-    heap->CreateFillerObjectAt(object->address(), kPointerSize);
-    return HeapObject::FromAddress(object->address() + kPointerSize);
-  } else {
-    heap->CreateFillerObjectAt(object->address() + size - kPointerSize,
-                               kPointerSize);
-    return object;
-  }
-}
-
-
-enum LoggingAndProfiling {
-  LOGGING_AND_PROFILING_ENABLED,
-  LOGGING_AND_PROFILING_DISABLED
-};
-
-
-enum MarksHandling { TRANSFER_MARKS, IGNORE_MARKS };
-
-
-template<MarksHandling marks_handling,
-         LoggingAndProfiling logging_and_profiling_mode>
-class ScavengingVisitor : public StaticVisitorBase {
- public:
-  static void Initialize() {
-    table_.Register(kVisitSeqOneByteString, &EvacuateSeqOneByteString);
-    table_.Register(kVisitSeqTwoByteString, &EvacuateSeqTwoByteString);
-    table_.Register(kVisitShortcutCandidate, &EvacuateShortcutCandidate);
-    table_.Register(kVisitByteArray, &EvacuateByteArray);
-    table_.Register(kVisitFixedArray, &EvacuateFixedArray);
-    table_.Register(kVisitFixedDoubleArray, &EvacuateFixedDoubleArray);
-    table_.Register(kVisitFixedTypedArray, &EvacuateFixedTypedArray);
-    table_.Register(kVisitFixedFloat64Array, &EvacuateFixedFloat64Array);
-
-    table_.Register(kVisitNativeContext,
-                    &ObjectEvacuationStrategy<POINTER_OBJECT>::
-                        template VisitSpecialized<Context::kSize>);
-
-    table_.Register(kVisitConsString,
-                    &ObjectEvacuationStrategy<POINTER_OBJECT>::
-                        template VisitSpecialized<ConsString::kSize>);
-
-    table_.Register(kVisitSlicedString,
-                    &ObjectEvacuationStrategy<POINTER_OBJECT>::
-                        template VisitSpecialized<SlicedString::kSize>);
-
-    table_.Register(kVisitSymbol,
-                    &ObjectEvacuationStrategy<POINTER_OBJECT>::
-                        template VisitSpecialized<Symbol::kSize>);
-
-    table_.Register(kVisitSharedFunctionInfo,
-                    &ObjectEvacuationStrategy<POINTER_OBJECT>::
-                        template VisitSpecialized<SharedFunctionInfo::kSize>);
-
-    table_.Register(kVisitJSWeakCollection,
-                    &ObjectEvacuationStrategy<POINTER_OBJECT>::
-                    Visit);
-
-    table_.Register(kVisitJSArrayBuffer,
-                    &ObjectEvacuationStrategy<POINTER_OBJECT>::
-                    Visit);
-
-    table_.Register(kVisitJSTypedArray,
-                    &ObjectEvacuationStrategy<POINTER_OBJECT>::
-                    Visit);
-
-    table_.Register(kVisitJSDataView,
-                    &ObjectEvacuationStrategy<POINTER_OBJECT>::
-                    Visit);
-
-    table_.Register(kVisitJSRegExp,
-                    &ObjectEvacuationStrategy<POINTER_OBJECT>::
-                    Visit);
-
-    if (marks_handling == IGNORE_MARKS) {
-      table_.Register(kVisitJSFunction,
-                      &ObjectEvacuationStrategy<POINTER_OBJECT>::
-                          template VisitSpecialized<JSFunction::kSize>);
-    } else {
-      table_.Register(kVisitJSFunction, &EvacuateJSFunction);
-    }
-
-    table_.RegisterSpecializations<ObjectEvacuationStrategy<DATA_OBJECT>,
-                                   kVisitDataObject,
-                                   kVisitDataObjectGeneric>();
-
-    table_.RegisterSpecializations<ObjectEvacuationStrategy<POINTER_OBJECT>,
-                                   kVisitJSObject,
-                                   kVisitJSObjectGeneric>();
-
-    table_.RegisterSpecializations<ObjectEvacuationStrategy<POINTER_OBJECT>,
-                                   kVisitStruct,
-                                   kVisitStructGeneric>();
-  }
-
-  static VisitorDispatchTable<ScavengingCallback>* GetTable() {
-    return &table_;
-  }
-
- private:
-  enum ObjectContents  { DATA_OBJECT, POINTER_OBJECT };
-
-  static void RecordCopiedObject(Heap* heap, HeapObject* obj) {
-    bool should_record = false;
-#ifdef DEBUG
-    should_record = FLAG_heap_stats;
-#endif
-    should_record = should_record || FLAG_log_gc;
-    if (should_record) {
-      if (heap->new_space()->Contains(obj)) {
-        heap->new_space()->RecordAllocation(obj);
-      } else {
-        heap->new_space()->RecordPromotion(obj);
-      }
-    }
-  }
-
-  // Helper function used by CopyObject to copy a source object to an
-  // allocated target object and update the forwarding pointer in the source
-  // object.  Returns the target object.
-  INLINE(static void MigrateObject(Heap* heap,
-                                   HeapObject* source,
-                                   HeapObject* target,
-                                   int size)) {
-    // If we migrate into to-space, then the to-space top pointer should be
-    // right after the target object. Incorporate double alignment
-    // over-allocation.
-    DCHECK(!heap->InToSpace(target) ||
-        target->address() + size == heap->new_space()->top() ||
-        target->address() + size + kPointerSize == heap->new_space()->top());
-
-    // Make sure that we do not overwrite the promotion queue which is at
-    // the end of to-space.
-    DCHECK(!heap->InToSpace(target) ||
-        heap->promotion_queue()->IsBelowPromotionQueue(
-            heap->new_space()->top()));
-
-    // Copy the content of source to target.
-    heap->CopyBlock(target->address(), source->address(), size);
-
-    // Set the forwarding address.
-    source->set_map_word(MapWord::FromForwardingAddress(target));
-
-    if (logging_and_profiling_mode == LOGGING_AND_PROFILING_ENABLED) {
-      // Update NewSpace stats if necessary.
-      RecordCopiedObject(heap, target);
-      heap->OnMoveEvent(target, source, size);
-    }
-
-    if (marks_handling == TRANSFER_MARKS) {
-      if (Marking::TransferColor(source, target)) {
-        MemoryChunk::IncrementLiveBytesFromGC(target->address(), size);
-      }
-    }
-  }
-
-  template<int alignment>
-  static inline bool SemiSpaceCopyObject(Map* map,
-                                         HeapObject** slot,
-                                         HeapObject* object,
-                                         int object_size) {
-    Heap* heap = map->GetHeap();
-
-    int allocation_size = object_size;
-    if (alignment != kObjectAlignment) {
-      DCHECK(alignment == kDoubleAlignment);
-      allocation_size += kPointerSize;
-    }
-
-    DCHECK(heap->AllowedToBeMigrated(object, NEW_SPACE));
-    AllocationResult allocation =
-        heap->new_space()->AllocateRaw(allocation_size);
-
-    HeapObject* target = NULL;  // Initialization to please compiler.
-    if (allocation.To(&target)) {
-      if (alignment != kObjectAlignment) {
-        target = EnsureDoubleAligned(heap, target, allocation_size);
-      }
-
-      // Order is important here: Set the promotion limit before migrating
-      // the object. Otherwise we may end up overwriting promotion queue
-      // entries when we migrate the object.
-      heap->promotion_queue()->SetNewLimit(heap->new_space()->top());
-
-      // Order is important: slot might be inside of the target if target
-      // was allocated over a dead object and slot comes from the store
-      // buffer.
-      *slot = target;
-      MigrateObject(heap, object, target, object_size);
-
-      heap->IncrementSemiSpaceCopiedObjectSize(object_size);
-      return true;
-    }
-    return false;
-  }
-
-
-  template<ObjectContents object_contents, int alignment>
-  static inline bool PromoteObject(Map* map,
-                                   HeapObject** slot,
-                                   HeapObject* object,
-                                   int object_size) {
-    Heap* heap = map->GetHeap();
-
-    int allocation_size = object_size;
-    if (alignment != kObjectAlignment) {
-      DCHECK(alignment == kDoubleAlignment);
-      allocation_size += kPointerSize;
-    }
-
-    AllocationResult allocation;
-    if (object_contents == DATA_OBJECT) {
-      DCHECK(heap->AllowedToBeMigrated(object, OLD_DATA_SPACE));
-      allocation = heap->old_data_space()->AllocateRaw(allocation_size);
-    } else {
-      DCHECK(heap->AllowedToBeMigrated(object, OLD_POINTER_SPACE));
-      allocation = heap->old_pointer_space()->AllocateRaw(allocation_size);
-    }
-
-    HeapObject* target = NULL;  // Initialization to please compiler.
-    if (allocation.To(&target)) {
-      if (alignment != kObjectAlignment) {
-        target = EnsureDoubleAligned(heap, target, allocation_size);
-      }
-
-      // Order is important: slot might be inside of the target if target
-      // was allocated over a dead object and slot comes from the store
-      // buffer.
-      *slot = target;
-      MigrateObject(heap, object, target, object_size);
-
-      if (object_contents == POINTER_OBJECT) {
-        if (map->instance_type() == JS_FUNCTION_TYPE) {
-          heap->promotion_queue()->insert(
-              target, JSFunction::kNonWeakFieldsEndOffset);
-        } else {
-          heap->promotion_queue()->insert(target, object_size);
-        }
-      }
-      heap->IncrementPromotedObjectsSize(object_size);
-      return true;
-    }
-    return false;
-  }
-
-
-  template<ObjectContents object_contents, int alignment>
-  static inline void EvacuateObject(Map* map,
-                                    HeapObject** slot,
-                                    HeapObject* object,
-                                    int object_size) {
-    SLOW_DCHECK(object_size <= Page::kMaxRegularHeapObjectSize);
-    SLOW_DCHECK(object->Size() == object_size);
-    Heap* heap = map->GetHeap();
-
-    if (!heap->ShouldBePromoted(object->address(), object_size)) {
-      // A semi-space copy may fail due to fragmentation. In that case, we
-      // try to promote the object.
-      if (SemiSpaceCopyObject<alignment>(map, slot, object, object_size)) {
-        return;
-      }
-    }
-
-    if (PromoteObject<object_contents, alignment>(
-        map, slot, object, object_size)) {
-      return;
-    }
-
-    // If promotion failed, we try to copy the object to the other semi-space
-    if (SemiSpaceCopyObject<alignment>(map, slot, object, object_size)) return;
-
-    UNREACHABLE();
-  }
-
-
-  static inline void EvacuateJSFunction(Map* map,
-                                        HeapObject** slot,
-                                        HeapObject* object) {
-    ObjectEvacuationStrategy<POINTER_OBJECT>::
-        template VisitSpecialized<JSFunction::kSize>(map, slot, object);
-
-    HeapObject* target = *slot;
-    MarkBit mark_bit = Marking::MarkBitFrom(target);
-    if (Marking::IsBlack(mark_bit)) {
-      // This object is black and it might not be rescanned by marker.
-      // We should explicitly record code entry slot for compaction because
-      // promotion queue processing (IterateAndMarkPointersToFromSpace) will
-      // miss it as it is not HeapObject-tagged.
-      Address code_entry_slot =
-          target->address() + JSFunction::kCodeEntryOffset;
-      Code* code = Code::cast(Code::GetObjectFromEntryAddress(code_entry_slot));
-      map->GetHeap()->mark_compact_collector()->
-          RecordCodeEntrySlot(code_entry_slot, code);
-    }
-  }
-
-
-  static inline void EvacuateFixedArray(Map* map,
-                                        HeapObject** slot,
-                                        HeapObject* object) {
-    int object_size = FixedArray::BodyDescriptor::SizeOf(map, object);
-    EvacuateObject<POINTER_OBJECT, kObjectAlignment>(
-        map, slot, object, object_size);
-  }
-
-
-  static inline void EvacuateFixedDoubleArray(Map* map,
-                                              HeapObject** slot,
-                                              HeapObject* object) {
-    int length = reinterpret_cast<FixedDoubleArray*>(object)->length();
-    int object_size = FixedDoubleArray::SizeFor(length);
-    EvacuateObject<DATA_OBJECT, kDoubleAlignment>(
-        map, slot, object, object_size);
-  }
-
-
-  static inline void EvacuateFixedTypedArray(Map* map,
-                                             HeapObject** slot,
-                                             HeapObject* object) {
-    int object_size = reinterpret_cast<FixedTypedArrayBase*>(object)->size();
-    EvacuateObject<DATA_OBJECT, kObjectAlignment>(
-        map, slot, object, object_size);
-  }
-
-
-  static inline void EvacuateFixedFloat64Array(Map* map,
-                                               HeapObject** slot,
-                                               HeapObject* object) {
-    int object_size = reinterpret_cast<FixedFloat64Array*>(object)->size();
-    EvacuateObject<DATA_OBJECT, kDoubleAlignment>(
-        map, slot, object, object_size);
-  }
-
-
-  static inline void EvacuateByteArray(Map* map,
-                                       HeapObject** slot,
-                                       HeapObject* object) {
-    int object_size = reinterpret_cast<ByteArray*>(object)->ByteArraySize();
-    EvacuateObject<DATA_OBJECT, kObjectAlignment>(
-        map, slot, object, object_size);
-  }
-
-
-  static inline void EvacuateSeqOneByteString(Map* map,
-                                            HeapObject** slot,
-                                            HeapObject* object) {
-    int object_size = SeqOneByteString::cast(object)->
-        SeqOneByteStringSize(map->instance_type());
-    EvacuateObject<DATA_OBJECT, kObjectAlignment>(
-        map, slot, object, object_size);
-  }
-
-
-  static inline void EvacuateSeqTwoByteString(Map* map,
-                                              HeapObject** slot,
-                                              HeapObject* object) {
-    int object_size = SeqTwoByteString::cast(object)->
-        SeqTwoByteStringSize(map->instance_type());
-    EvacuateObject<DATA_OBJECT, kObjectAlignment>(
-        map, slot, object, object_size);
-  }
-
-
-  static inline void EvacuateShortcutCandidate(Map* map,
-                                               HeapObject** slot,
-                                               HeapObject* object) {
-    DCHECK(IsShortcutCandidate(map->instance_type()));
-
-    Heap* heap = map->GetHeap();
-
-    if (marks_handling == IGNORE_MARKS &&
-        ConsString::cast(object)->unchecked_second() ==
-        heap->empty_string()) {
-      HeapObject* first =
-          HeapObject::cast(ConsString::cast(object)->unchecked_first());
-
-      *slot = first;
-
-      if (!heap->InNewSpace(first)) {
-        object->set_map_word(MapWord::FromForwardingAddress(first));
-        return;
-      }
-
-      MapWord first_word = first->map_word();
-      if (first_word.IsForwardingAddress()) {
-        HeapObject* target = first_word.ToForwardingAddress();
-
-        *slot = target;
-        object->set_map_word(MapWord::FromForwardingAddress(target));
-        return;
-      }
-
-      heap->DoScavengeObject(first->map(), slot, first);
-      object->set_map_word(MapWord::FromForwardingAddress(*slot));
-      return;
-    }
-
-    int object_size = ConsString::kSize;
-    EvacuateObject<POINTER_OBJECT, kObjectAlignment>(
-        map, slot, object, object_size);
-  }
-
-  template<ObjectContents object_contents>
-  class ObjectEvacuationStrategy {
-   public:
-    template<int object_size>
-    static inline void VisitSpecialized(Map* map,
-                                        HeapObject** slot,
-                                        HeapObject* object) {
-      EvacuateObject<object_contents, kObjectAlignment>(
-          map, slot, object, object_size);
-    }
-
-    static inline void Visit(Map* map,
-                             HeapObject** slot,
-                             HeapObject* object) {
-      int object_size = map->instance_size();
-      EvacuateObject<object_contents, kObjectAlignment>(
-          map, slot, object, object_size);
-    }
-  };
-
-  static VisitorDispatchTable<ScavengingCallback> table_;
-};
-
-
-template<MarksHandling marks_handling,
-         LoggingAndProfiling logging_and_profiling_mode>
-VisitorDispatchTable<ScavengingCallback>
-    ScavengingVisitor<marks_handling, logging_and_profiling_mode>::table_;
-
-
-static void InitializeScavengingVisitorsTables() {
-  ScavengingVisitor<TRANSFER_MARKS,
-                    LOGGING_AND_PROFILING_DISABLED>::Initialize();
-  ScavengingVisitor<IGNORE_MARKS, LOGGING_AND_PROFILING_DISABLED>::Initialize();
-  ScavengingVisitor<TRANSFER_MARKS,
-                    LOGGING_AND_PROFILING_ENABLED>::Initialize();
-  ScavengingVisitor<IGNORE_MARKS, LOGGING_AND_PROFILING_ENABLED>::Initialize();
-}
-
-
-void Heap::SelectScavengingVisitorsTable() {
-  bool logging_and_profiling =
-      FLAG_verify_predictable ||
-      isolate()->logger()->is_logging() ||
-      isolate()->cpu_profiler()->is_profiling() ||
-      (isolate()->heap_profiler() != NULL &&
-       isolate()->heap_profiler()->is_tracking_object_moves());
-
-  if (!incremental_marking()->IsMarking()) {
-    if (!logging_and_profiling) {
-      scavenging_visitors_table_.CopyFrom(
-          ScavengingVisitor<IGNORE_MARKS,
-                            LOGGING_AND_PROFILING_DISABLED>::GetTable());
-    } else {
-      scavenging_visitors_table_.CopyFrom(
-          ScavengingVisitor<IGNORE_MARKS,
-                            LOGGING_AND_PROFILING_ENABLED>::GetTable());
-    }
-  } else {
-    if (!logging_and_profiling) {
-      scavenging_visitors_table_.CopyFrom(
-          ScavengingVisitor<TRANSFER_MARKS,
-                            LOGGING_AND_PROFILING_DISABLED>::GetTable());
-    } else {
-      scavenging_visitors_table_.CopyFrom(
-          ScavengingVisitor<TRANSFER_MARKS,
-                            LOGGING_AND_PROFILING_ENABLED>::GetTable());
-    }
-
-    if (incremental_marking()->IsCompacting()) {
-      // When compacting forbid short-circuiting of cons-strings.
-      // Scavenging code relies on the fact that new space object
-      // can't be evacuated into evacuation candidate but
-      // short-circuiting violates this assumption.
-      scavenging_visitors_table_.Register(
-          StaticVisitorBase::kVisitShortcutCandidate,
-          scavenging_visitors_table_.GetVisitorById(
-              StaticVisitorBase::kVisitConsString));
-    }
-  }
-}
-
-
-void Heap::ScavengeObjectSlow(HeapObject** p, HeapObject* object) {
-  SLOW_DCHECK(object->GetIsolate()->heap()->InFromSpace(object));
-  MapWord first_word = object->map_word();
-  SLOW_DCHECK(!first_word.IsForwardingAddress());
-  Map* map = first_word.ToMap();
-  map->GetHeap()->DoScavengeObject(map, p, object);
-}
-
-
-AllocationResult Heap::AllocatePartialMap(InstanceType instance_type,
-                                          int instance_size) {
-  Object* result;
-  AllocationResult allocation = AllocateRaw(Map::kSize, MAP_SPACE, MAP_SPACE);
-  if (!allocation.To(&result)) return allocation;
-
-  // Map::cast cannot be used due to uninitialized map field.
-  reinterpret_cast<Map*>(result)->set_map(raw_unchecked_meta_map());
-  reinterpret_cast<Map*>(result)->set_instance_type(instance_type);
-  reinterpret_cast<Map*>(result)->set_instance_size(instance_size);
-  reinterpret_cast<Map*>(result)->set_visitor_id(
-        StaticVisitorBase::GetVisitorId(instance_type, instance_size));
-  reinterpret_cast<Map*>(result)->set_inobject_properties(0);
-  reinterpret_cast<Map*>(result)->set_pre_allocated_property_fields(0);
-  reinterpret_cast<Map*>(result)->set_unused_property_fields(0);
-  reinterpret_cast<Map*>(result)->set_bit_field(0);
-  reinterpret_cast<Map*>(result)->set_bit_field2(0);
-  int bit_field3 = Map::EnumLengthBits::encode(kInvalidEnumCacheSentinel) |
-                   Map::OwnsDescriptors::encode(true);
-  reinterpret_cast<Map*>(result)->set_bit_field3(bit_field3);
-  return result;
-}
-
-
-AllocationResult Heap::AllocateMap(InstanceType instance_type,
-                                   int instance_size,
-                                   ElementsKind elements_kind) {
-  HeapObject* result;
-  AllocationResult allocation = AllocateRaw(Map::kSize, MAP_SPACE, MAP_SPACE);
-  if (!allocation.To(&result)) return allocation;
-
-  result->set_map_no_write_barrier(meta_map());
-  Map* map = Map::cast(result);
-  map->set_instance_type(instance_type);
-  map->set_visitor_id(
-      StaticVisitorBase::GetVisitorId(instance_type, instance_size));
-  map->set_prototype(null_value(), SKIP_WRITE_BARRIER);
-  map->set_constructor(null_value(), SKIP_WRITE_BARRIER);
-  map->set_instance_size(instance_size);
-  map->set_inobject_properties(0);
-  map->set_pre_allocated_property_fields(0);
-  map->set_code_cache(empty_fixed_array(), SKIP_WRITE_BARRIER);
-  map->set_dependent_code(DependentCode::cast(empty_fixed_array()),
-                          SKIP_WRITE_BARRIER);
-  map->init_back_pointer(undefined_value());
-  map->set_unused_property_fields(0);
-  map->set_instance_descriptors(empty_descriptor_array());
-  map->set_bit_field(0);
-  map->set_bit_field2(1 << Map::kIsExtensible);
-  int bit_field3 = Map::EnumLengthBits::encode(kInvalidEnumCacheSentinel) |
-                   Map::OwnsDescriptors::encode(true);
-  map->set_bit_field3(bit_field3);
-  map->set_elements_kind(elements_kind);
-
-  return map;
-}
-
-
-AllocationResult Heap::AllocateFillerObject(int size,
-                                            bool double_align,
-                                            AllocationSpace space) {
-  HeapObject* obj;
-  { AllocationResult allocation = AllocateRaw(size, space, space);
-    if (!allocation.To(&obj)) return allocation;
-  }
-#ifdef DEBUG
-  MemoryChunk* chunk = MemoryChunk::FromAddress(obj->address());
-  DCHECK(chunk->owner()->identity() == space);
-#endif
-  CreateFillerObjectAt(obj->address(), size);
-  return obj;
-}
-
-
-const Heap::StringTypeTable Heap::string_type_table[] = {
-#define STRING_TYPE_ELEMENT(type, size, name, camel_name)                      \
-  {type, size, k##camel_name##MapRootIndex},
-  STRING_TYPE_LIST(STRING_TYPE_ELEMENT)
-#undef STRING_TYPE_ELEMENT
-};
-
-
-const Heap::ConstantStringTable Heap::constant_string_table[] = {
-#define CONSTANT_STRING_ELEMENT(name, contents)                                \
-  {contents, k##name##RootIndex},
-  INTERNALIZED_STRING_LIST(CONSTANT_STRING_ELEMENT)
-#undef CONSTANT_STRING_ELEMENT
-};
-
-
-const Heap::StructTable Heap::struct_table[] = {
-#define STRUCT_TABLE_ELEMENT(NAME, Name, name)                                 \
-  { NAME##_TYPE, Name::kSize, k##Name##MapRootIndex },
-  STRUCT_LIST(STRUCT_TABLE_ELEMENT)
-#undef STRUCT_TABLE_ELEMENT
-};
-
-
-bool Heap::CreateInitialMaps() {
-  HeapObject* obj;
-  { AllocationResult allocation = AllocatePartialMap(MAP_TYPE, Map::kSize);
-    if (!allocation.To(&obj)) return false;
-  }
-  // Map::cast cannot be used due to uninitialized map field.
-  Map* new_meta_map = reinterpret_cast<Map*>(obj);
-  set_meta_map(new_meta_map);
-  new_meta_map->set_map(new_meta_map);
-
-  {  // Partial map allocation
-#define ALLOCATE_PARTIAL_MAP(instance_type, size, field_name)                  \
-    { Map* map;                                                                \
-      if (!AllocatePartialMap((instance_type), (size)).To(&map)) return false; \
-      set_##field_name##_map(map);                                             \
-    }
-
-    ALLOCATE_PARTIAL_MAP(FIXED_ARRAY_TYPE, kVariableSizeSentinel, fixed_array);
-    ALLOCATE_PARTIAL_MAP(ODDBALL_TYPE, Oddball::kSize, undefined);
-    ALLOCATE_PARTIAL_MAP(ODDBALL_TYPE, Oddball::kSize, null);
-    ALLOCATE_PARTIAL_MAP(CONSTANT_POOL_ARRAY_TYPE, kVariableSizeSentinel,
-                         constant_pool_array);
-
-#undef ALLOCATE_PARTIAL_MAP
-  }
-
-  // Allocate the empty array.
-  { AllocationResult allocation = AllocateEmptyFixedArray();
-    if (!allocation.To(&obj)) return false;
-  }
-  set_empty_fixed_array(FixedArray::cast(obj));
-
-  { AllocationResult allocation = Allocate(null_map(), OLD_POINTER_SPACE);
-    if (!allocation.To(&obj)) return false;
-  }
-  set_null_value(Oddball::cast(obj));
-  Oddball::cast(obj)->set_kind(Oddball::kNull);
-
-  { AllocationResult allocation = Allocate(undefined_map(), OLD_POINTER_SPACE);
-    if (!allocation.To(&obj)) return false;
-  }
-  set_undefined_value(Oddball::cast(obj));
-  Oddball::cast(obj)->set_kind(Oddball::kUndefined);
-  DCHECK(!InNewSpace(undefined_value()));
-
-  // Set preliminary exception sentinel value before actually initializing it.
-  set_exception(null_value());
-
-  // Allocate the empty descriptor array.
-  { AllocationResult allocation = AllocateEmptyFixedArray();
-    if (!allocation.To(&obj)) return false;
-  }
-  set_empty_descriptor_array(DescriptorArray::cast(obj));
-
-  // Allocate the constant pool array.
-  { AllocationResult allocation = AllocateEmptyConstantPoolArray();
-    if (!allocation.To(&obj)) return false;
-  }
-  set_empty_constant_pool_array(ConstantPoolArray::cast(obj));
-
-  // Fix the instance_descriptors for the existing maps.
-  meta_map()->set_code_cache(empty_fixed_array());
-  meta_map()->set_dependent_code(DependentCode::cast(empty_fixed_array()));
-  meta_map()->init_back_pointer(undefined_value());
-  meta_map()->set_instance_descriptors(empty_descriptor_array());
-
-  fixed_array_map()->set_code_cache(empty_fixed_array());
-  fixed_array_map()->set_dependent_code(
-      DependentCode::cast(empty_fixed_array()));
-  fixed_array_map()->init_back_pointer(undefined_value());
-  fixed_array_map()->set_instance_descriptors(empty_descriptor_array());
-
-  undefined_map()->set_code_cache(empty_fixed_array());
-  undefined_map()->set_dependent_code(DependentCode::cast(empty_fixed_array()));
-  undefined_map()->init_back_pointer(undefined_value());
-  undefined_map()->set_instance_descriptors(empty_descriptor_array());
-
-  null_map()->set_code_cache(empty_fixed_array());
-  null_map()->set_dependent_code(DependentCode::cast(empty_fixed_array()));
-  null_map()->init_back_pointer(undefined_value());
-  null_map()->set_instance_descriptors(empty_descriptor_array());
-
-  constant_pool_array_map()->set_code_cache(empty_fixed_array());
-  constant_pool_array_map()->set_dependent_code(
-      DependentCode::cast(empty_fixed_array()));
-  constant_pool_array_map()->init_back_pointer(undefined_value());
-  constant_pool_array_map()->set_instance_descriptors(empty_descriptor_array());
-
-  // Fix prototype object for existing maps.
-  meta_map()->set_prototype(null_value());
-  meta_map()->set_constructor(null_value());
-
-  fixed_array_map()->set_prototype(null_value());
-  fixed_array_map()->set_constructor(null_value());
-
-  undefined_map()->set_prototype(null_value());
-  undefined_map()->set_constructor(null_value());
-
-  null_map()->set_prototype(null_value());
-  null_map()->set_constructor(null_value());
-
-  constant_pool_array_map()->set_prototype(null_value());
-  constant_pool_array_map()->set_constructor(null_value());
-
-  {  // Map allocation
-#define ALLOCATE_MAP(instance_type, size, field_name)                          \
-    { Map* map;                                                                \
-      if (!AllocateMap((instance_type), size).To(&map)) return false;          \
-      set_##field_name##_map(map);                                             \
-    }
-
-#define ALLOCATE_VARSIZE_MAP(instance_type, field_name)                        \
-    ALLOCATE_MAP(instance_type, kVariableSizeSentinel, field_name)
-
-    ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, fixed_cow_array)
-    DCHECK(fixed_array_map() != fixed_cow_array_map());
-
-    ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, scope_info)
-    ALLOCATE_MAP(HEAP_NUMBER_TYPE, HeapNumber::kSize, heap_number)
-    ALLOCATE_MAP(
-        MUTABLE_HEAP_NUMBER_TYPE, HeapNumber::kSize, mutable_heap_number)
-    ALLOCATE_MAP(SYMBOL_TYPE, Symbol::kSize, symbol)
-    ALLOCATE_MAP(FOREIGN_TYPE, Foreign::kSize, foreign)
-
-    ALLOCATE_MAP(ODDBALL_TYPE, Oddball::kSize, the_hole);
-    ALLOCATE_MAP(ODDBALL_TYPE, Oddball::kSize, boolean);
-    ALLOCATE_MAP(ODDBALL_TYPE, Oddball::kSize, uninitialized);
-    ALLOCATE_MAP(ODDBALL_TYPE, Oddball::kSize, arguments_marker);
-    ALLOCATE_MAP(ODDBALL_TYPE, Oddball::kSize, no_interceptor_result_sentinel);
-    ALLOCATE_MAP(ODDBALL_TYPE, Oddball::kSize, exception);
-    ALLOCATE_MAP(ODDBALL_TYPE, Oddball::kSize, termination_exception);
-
-    for (unsigned i = 0; i < ARRAY_SIZE(string_type_table); i++) {
-      const StringTypeTable& entry = string_type_table[i];
-      { AllocationResult allocation = AllocateMap(entry.type, entry.size);
-        if (!allocation.To(&obj)) return false;
-      }
-      // Mark cons string maps as unstable, because their objects can change
-      // maps during GC.
-      Map* map = Map::cast(obj);
-      if (StringShape(entry.type).IsCons()) map->mark_unstable();
-      roots_[entry.index] = map;
-    }
-
-    ALLOCATE_VARSIZE_MAP(STRING_TYPE, undetectable_string)
-    undetectable_string_map()->set_is_undetectable();
-
-    ALLOCATE_VARSIZE_MAP(ASCII_STRING_TYPE, undetectable_ascii_string);
-    undetectable_ascii_string_map()->set_is_undetectable();
-
-    ALLOCATE_VARSIZE_MAP(FIXED_DOUBLE_ARRAY_TYPE, fixed_double_array)
-    ALLOCATE_VARSIZE_MAP(BYTE_ARRAY_TYPE, byte_array)
-    ALLOCATE_VARSIZE_MAP(FREE_SPACE_TYPE, free_space)
-
-#define ALLOCATE_EXTERNAL_ARRAY_MAP(Type, type, TYPE, ctype, size)            \
-    ALLOCATE_MAP(EXTERNAL_##TYPE##_ARRAY_TYPE, ExternalArray::kAlignedSize,   \
-        external_##type##_array)
-
-     TYPED_ARRAYS(ALLOCATE_EXTERNAL_ARRAY_MAP)
-#undef ALLOCATE_EXTERNAL_ARRAY_MAP
-
-#define ALLOCATE_FIXED_TYPED_ARRAY_MAP(Type, type, TYPE, ctype, size)         \
-    ALLOCATE_VARSIZE_MAP(FIXED_##TYPE##_ARRAY_TYPE,                           \
-        fixed_##type##_array)
-
-     TYPED_ARRAYS(ALLOCATE_FIXED_TYPED_ARRAY_MAP)
-#undef ALLOCATE_FIXED_TYPED_ARRAY_MAP
-
-    ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, sloppy_arguments_elements)
-
-    ALLOCATE_VARSIZE_MAP(CODE_TYPE, code)
-
-    ALLOCATE_MAP(CELL_TYPE, Cell::kSize, cell)
-    ALLOCATE_MAP(PROPERTY_CELL_TYPE, PropertyCell::kSize, global_property_cell)
-    ALLOCATE_MAP(FILLER_TYPE, kPointerSize, one_pointer_filler)
-    ALLOCATE_MAP(FILLER_TYPE, 2 * kPointerSize, two_pointer_filler)
-
-
-    for (unsigned i = 0; i < ARRAY_SIZE(struct_table); i++) {
-      const StructTable& entry = struct_table[i];
-      Map* map;
-      if (!AllocateMap(entry.type, entry.size).To(&map))
-        return false;
-      roots_[entry.index] = map;
-    }
-
-    ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, hash_table)
-    ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, ordered_hash_table)
-
-    ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, function_context)
-    ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, catch_context)
-    ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, with_context)
-    ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, block_context)
-    ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, module_context)
-    ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, global_context)
-
-    ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, native_context)
-    native_context_map()->set_dictionary_map(true);
-    native_context_map()->set_visitor_id(
-        StaticVisitorBase::kVisitNativeContext);
-
-    ALLOCATE_MAP(SHARED_FUNCTION_INFO_TYPE, SharedFunctionInfo::kAlignedSize,
-        shared_function_info)
-
-    ALLOCATE_MAP(JS_MESSAGE_OBJECT_TYPE, JSMessageObject::kSize,
-        message_object)
-    ALLOCATE_MAP(JS_OBJECT_TYPE, JSObject::kHeaderSize + kPointerSize,
-        external)
-    external_map()->set_is_extensible(false);
-#undef ALLOCATE_VARSIZE_MAP
-#undef ALLOCATE_MAP
-  }
-
-  { // Empty arrays
-    { ByteArray* byte_array;
-      if (!AllocateByteArray(0, TENURED).To(&byte_array)) return false;
-      set_empty_byte_array(byte_array);
-    }
-
-#define ALLOCATE_EMPTY_EXTERNAL_ARRAY(Type, type, TYPE, ctype, size)           \
-    { ExternalArray* obj;                                                      \
-      if (!AllocateEmptyExternalArray(kExternal##Type##Array).To(&obj))        \
-          return false;                                                        \
-      set_empty_external_##type##_array(obj);                                  \
-    }
-
-    TYPED_ARRAYS(ALLOCATE_EMPTY_EXTERNAL_ARRAY)
-#undef ALLOCATE_EMPTY_EXTERNAL_ARRAY
-
-#define ALLOCATE_EMPTY_FIXED_TYPED_ARRAY(Type, type, TYPE, ctype, size)        \
-    { FixedTypedArrayBase* obj;                                                \
-      if (!AllocateEmptyFixedTypedArray(kExternal##Type##Array).To(&obj))      \
-          return false;                                                        \
-      set_empty_fixed_##type##_array(obj);                                     \
-    }
-
-    TYPED_ARRAYS(ALLOCATE_EMPTY_FIXED_TYPED_ARRAY)
-#undef ALLOCATE_EMPTY_FIXED_TYPED_ARRAY
-  }
-  DCHECK(!InNewSpace(empty_fixed_array()));
-  return true;
-}
-
-
-AllocationResult Heap::AllocateHeapNumber(double value,
-                                          MutableMode mode,
-                                          PretenureFlag pretenure) {
-  // Statically ensure that it is safe to allocate heap numbers in paged
-  // spaces.
-  int size = HeapNumber::kSize;
-  STATIC_ASSERT(HeapNumber::kSize <= Page::kMaxRegularHeapObjectSize);
-
-  AllocationSpace space = SelectSpace(size, OLD_DATA_SPACE, pretenure);
-
-  HeapObject* result;
-  { AllocationResult allocation = AllocateRaw(size, space, OLD_DATA_SPACE);
-    if (!allocation.To(&result)) return allocation;
-  }
-
-  Map* map = mode == MUTABLE ? mutable_heap_number_map() : heap_number_map();
-  HeapObject::cast(result)->set_map_no_write_barrier(map);
-  HeapNumber::cast(result)->set_value(value);
-  return result;
-}
-
-
-AllocationResult Heap::AllocateCell(Object* value) {
-  int size = Cell::kSize;
-  STATIC_ASSERT(Cell::kSize <= Page::kMaxRegularHeapObjectSize);
-
-  HeapObject* result;
-  { AllocationResult allocation = AllocateRaw(size, CELL_SPACE, CELL_SPACE);
-    if (!allocation.To(&result)) return allocation;
-  }
-  result->set_map_no_write_barrier(cell_map());
-  Cell::cast(result)->set_value(value);
-  return result;
-}
-
-
-AllocationResult Heap::AllocatePropertyCell() {
-  int size = PropertyCell::kSize;
-  STATIC_ASSERT(PropertyCell::kSize <= Page::kMaxRegularHeapObjectSize);
-
-  HeapObject* result;
-  AllocationResult allocation =
-      AllocateRaw(size, PROPERTY_CELL_SPACE, PROPERTY_CELL_SPACE);
-  if (!allocation.To(&result)) return allocation;
-
-  result->set_map_no_write_barrier(global_property_cell_map());
-  PropertyCell* cell = PropertyCell::cast(result);
-  cell->set_dependent_code(DependentCode::cast(empty_fixed_array()),
-                           SKIP_WRITE_BARRIER);
-  cell->set_value(the_hole_value());
-  cell->set_type(HeapType::None());
-  return result;
-}
-
-
-void Heap::CreateApiObjects() {
-  HandleScope scope(isolate());
-  Factory* factory = isolate()->factory();
-  Handle<Map> new_neander_map =
-      factory->NewMap(JS_OBJECT_TYPE, JSObject::kHeaderSize);
-
-  // Don't use Smi-only elements optimizations for objects with the neander
-  // map. There are too many cases where element values are set directly with a
-  // bottleneck to trap the Smi-only -> fast elements transition, and there
-  // appears to be no benefit for optimize this case.
-  new_neander_map->set_elements_kind(TERMINAL_FAST_ELEMENTS_KIND);
-  set_neander_map(*new_neander_map);
-
-  Handle<JSObject> listeners = factory->NewNeanderObject();
-  Handle<FixedArray> elements = factory->NewFixedArray(2);
-  elements->set(0, Smi::FromInt(0));
-  listeners->set_elements(*elements);
-  set_message_listeners(*listeners);
-}
-
-
-void Heap::CreateJSEntryStub() {
-  JSEntryStub stub(isolate());
-  set_js_entry_code(*stub.GetCode());
-}
-
-
-void Heap::CreateJSConstructEntryStub() {
-  JSConstructEntryStub stub(isolate());
-  set_js_construct_entry_code(*stub.GetCode());
-}
-
-
-void Heap::CreateFixedStubs() {
-  // Here we create roots for fixed stubs. They are needed at GC
-  // for cooking and uncooking (check out frames.cc).
-  // The eliminates the need for doing dictionary lookup in the
-  // stub cache for these stubs.
-  HandleScope scope(isolate());
-
-  // Create stubs that should be there, so we don't unexpectedly have to
-  // create them if we need them during the creation of another stub.
-  // Stub creation mixes raw pointers and handles in an unsafe manner so
-  // we cannot create stubs while we are creating stubs.
-  CodeStub::GenerateStubsAheadOfTime(isolate());
-
-  // MacroAssembler::Abort calls (usually enabled with --debug-code) depend on
-  // CEntryStub, so we need to call GenerateStubsAheadOfTime before JSEntryStub
-  // is created.
-
-  // gcc-4.4 has problem generating correct code of following snippet:
-  // {  JSEntryStub stub;
-  //    js_entry_code_ = *stub.GetCode();
-  // }
-  // {  JSConstructEntryStub stub;
-  //    js_construct_entry_code_ = *stub.GetCode();
-  // }
-  // To workaround the problem, make separate functions without inlining.
-  Heap::CreateJSEntryStub();
-  Heap::CreateJSConstructEntryStub();
-}
-
-
-void Heap::CreateInitialObjects() {
-  HandleScope scope(isolate());
-  Factory* factory = isolate()->factory();
-
-  // The -0 value must be set before NewNumber works.
-  set_minus_zero_value(*factory->NewHeapNumber(-0.0, IMMUTABLE, TENURED));
-  DCHECK(std::signbit(minus_zero_value()->Number()) != 0);
-
-  set_nan_value(
-      *factory->NewHeapNumber(base::OS::nan_value(), IMMUTABLE, TENURED));
-  set_infinity_value(*factory->NewHeapNumber(V8_INFINITY, IMMUTABLE, TENURED));
-
-  // The hole has not been created yet, but we want to put something
-  // predictable in the gaps in the string table, so lets make that Smi zero.
-  set_the_hole_value(reinterpret_cast<Oddball*>(Smi::FromInt(0)));
-
-  // Allocate initial string table.
-  set_string_table(*StringTable::New(isolate(), kInitialStringTableSize));
-
-  // Finish initializing oddballs after creating the string table.
-  Oddball::Initialize(isolate(),
-                      factory->undefined_value(),
-                      "undefined",
-                      factory->nan_value(),
-                      Oddball::kUndefined);
-
-  // Initialize the null_value.
-  Oddball::Initialize(isolate(),
-                      factory->null_value(),
-                      "null",
-                      handle(Smi::FromInt(0), isolate()),
-                      Oddball::kNull);
-
-  set_true_value(*factory->NewOddball(factory->boolean_map(),
-                                      "true",
-                                      handle(Smi::FromInt(1), isolate()),
-                                      Oddball::kTrue));
-
-  set_false_value(*factory->NewOddball(factory->boolean_map(),
-                                       "false",
-                                       handle(Smi::FromInt(0), isolate()),
-                                       Oddball::kFalse));
-
-  set_the_hole_value(*factory->NewOddball(factory->the_hole_map(),
-                                          "hole",
-                                          handle(Smi::FromInt(-1), isolate()),
-                                          Oddball::kTheHole));
-
-  set_uninitialized_value(
-      *factory->NewOddball(factory->uninitialized_map(),
-                           "uninitialized",
-                           handle(Smi::FromInt(-1), isolate()),
-                           Oddball::kUninitialized));
-
-  set_arguments_marker(*factory->NewOddball(factory->arguments_marker_map(),
-                                            "arguments_marker",
-                                            handle(Smi::FromInt(-4), isolate()),
-                                            Oddball::kArgumentMarker));
-
-  set_no_interceptor_result_sentinel(
-      *factory->NewOddball(factory->no_interceptor_result_sentinel_map(),
-                           "no_interceptor_result_sentinel",
-                           handle(Smi::FromInt(-2), isolate()),
-                           Oddball::kOther));
-
-  set_termination_exception(
-      *factory->NewOddball(factory->termination_exception_map(),
-                           "termination_exception",
-                           handle(Smi::FromInt(-3), isolate()),
-                           Oddball::kOther));
-
-  set_exception(
-      *factory->NewOddball(factory->exception_map(),
-                           "exception",
-                           handle(Smi::FromInt(-5), isolate()),
-                           Oddball::kException));
-
-  for (unsigned i = 0; i < ARRAY_SIZE(constant_string_table); i++) {
-    Handle<String> str =
-        factory->InternalizeUtf8String(constant_string_table[i].contents);
-    roots_[constant_string_table[i].index] = *str;
-  }
-
-  // Allocate the hidden string which is used to identify the hidden properties
-  // in JSObjects. The hash code has a special value so that it will not match
-  // the empty string when searching for the property. It cannot be part of the
-  // loop above because it needs to be allocated manually with the special
-  // hash code in place. The hash code for the hidden_string is zero to ensure
-  // that it will always be at the first entry in property descriptors.
-  hidden_string_ = *factory->NewOneByteInternalizedString(
-      OneByteVector("", 0), String::kEmptyStringHash);
-
-  // Create the code_stubs dictionary. The initial size is set to avoid
-  // expanding the dictionary during bootstrapping.
-  set_code_stubs(*UnseededNumberDictionary::New(isolate(), 128));
-
-  // Create the non_monomorphic_cache used in stub-cache.cc. The initial size
-  // is set to avoid expanding the dictionary during bootstrapping.
-  set_non_monomorphic_cache(*UnseededNumberDictionary::New(isolate(), 64));
-
-  set_polymorphic_code_cache(PolymorphicCodeCache::cast(
-      *factory->NewStruct(POLYMORPHIC_CODE_CACHE_TYPE)));
-
-  set_instanceof_cache_function(Smi::FromInt(0));
-  set_instanceof_cache_map(Smi::FromInt(0));
-  set_instanceof_cache_answer(Smi::FromInt(0));
-
-  CreateFixedStubs();
-
-  // Allocate the dictionary of intrinsic function names.
-  Handle<NameDictionary> intrinsic_names =
-      NameDictionary::New(isolate(), Runtime::kNumFunctions);
-  Runtime::InitializeIntrinsicFunctionNames(isolate(), intrinsic_names);
-  set_intrinsic_function_names(*intrinsic_names);
-
-  set_number_string_cache(*factory->NewFixedArray(
-      kInitialNumberStringCacheSize * 2, TENURED));
-
-  // Allocate cache for single character one byte strings.
-  set_single_character_string_cache(*factory->NewFixedArray(
-      String::kMaxOneByteCharCode + 1, TENURED));
-
-  // Allocate cache for string split and regexp-multiple.
-  set_string_split_cache(*factory->NewFixedArray(
-      RegExpResultsCache::kRegExpResultsCacheSize, TENURED));
-  set_regexp_multiple_cache(*factory->NewFixedArray(
-      RegExpResultsCache::kRegExpResultsCacheSize, TENURED));
-
-  // Allocate cache for external strings pointing to native source code.
-  set_natives_source_cache(*factory->NewFixedArray(
-      Natives::GetBuiltinsCount()));
-
-  set_undefined_cell(*factory->NewCell(factory->undefined_value()));
-
-  // The symbol registry is initialized lazily.
-  set_symbol_registry(undefined_value());
-
-  // Allocate object to hold object observation state.
-  set_observation_state(*factory->NewJSObjectFromMap(
-      factory->NewMap(JS_OBJECT_TYPE, JSObject::kHeaderSize)));
-
-  // Microtask queue uses the empty fixed array as a sentinel for "empty".
-  // Number of queued microtasks stored in Isolate::pending_microtask_count().
-  set_microtask_queue(empty_fixed_array());
-
-  set_detailed_stack_trace_symbol(*factory->NewPrivateSymbol());
-  set_elements_transition_symbol(*factory->NewPrivateSymbol());
-  set_frozen_symbol(*factory->NewPrivateSymbol());
-  set_megamorphic_symbol(*factory->NewPrivateSymbol());
-  set_nonexistent_symbol(*factory->NewPrivateSymbol());
-  set_normal_ic_symbol(*factory->NewPrivateSymbol());
-  set_observed_symbol(*factory->NewPrivateSymbol());
-  set_stack_trace_symbol(*factory->NewPrivateSymbol());
-  set_uninitialized_symbol(*factory->NewPrivateSymbol());
-
-  Handle<SeededNumberDictionary> slow_element_dictionary =
-      SeededNumberDictionary::New(isolate(), 0, TENURED);
-  slow_element_dictionary->set_requires_slow_elements();
-  set_empty_slow_element_dictionary(*slow_element_dictionary);
-
-  set_materialized_objects(*factory->NewFixedArray(0, TENURED));
-
-  // Handling of script id generation is in Factory::NewScript.
-  set_last_script_id(Smi::FromInt(v8::UnboundScript::kNoScriptId));
-
-  set_allocation_sites_scratchpad(*factory->NewFixedArray(
-      kAllocationSiteScratchpadSize, TENURED));
-  InitializeAllocationSitesScratchpad();
-
-  // Initialize keyed lookup cache.
-  isolate_->keyed_lookup_cache()->Clear();
-
-  // Initialize context slot cache.
-  isolate_->context_slot_cache()->Clear();
-
-  // Initialize descriptor cache.
-  isolate_->descriptor_lookup_cache()->Clear();
-
-  // Initialize compilation cache.
-  isolate_->compilation_cache()->Clear();
-}
-
-
-bool Heap::RootCanBeWrittenAfterInitialization(Heap::RootListIndex root_index) {
-  RootListIndex writable_roots[] = {
-    kStoreBufferTopRootIndex,
-    kStackLimitRootIndex,
-    kNumberStringCacheRootIndex,
-    kInstanceofCacheFunctionRootIndex,
-    kInstanceofCacheMapRootIndex,
-    kInstanceofCacheAnswerRootIndex,
-    kCodeStubsRootIndex,
-    kNonMonomorphicCacheRootIndex,
-    kPolymorphicCodeCacheRootIndex,
-    kLastScriptIdRootIndex,
-    kEmptyScriptRootIndex,
-    kRealStackLimitRootIndex,
-    kArgumentsAdaptorDeoptPCOffsetRootIndex,
-    kConstructStubDeoptPCOffsetRootIndex,
-    kGetterStubDeoptPCOffsetRootIndex,
-    kSetterStubDeoptPCOffsetRootIndex,
-    kStringTableRootIndex,
-  };
-
-  for (unsigned int i = 0; i < ARRAY_SIZE(writable_roots); i++) {
-    if (root_index == writable_roots[i])
-      return true;
-  }
-  return false;
-}
-
-
-bool Heap::RootCanBeTreatedAsConstant(RootListIndex root_index) {
-  return !RootCanBeWrittenAfterInitialization(root_index) &&
-      !InNewSpace(roots_array_start()[root_index]);
-}
-
-
-Object* RegExpResultsCache::Lookup(Heap* heap,
-                                   String* key_string,
-                                   Object* key_pattern,
-                                   ResultsCacheType type) {
-  FixedArray* cache;
-  if (!key_string->IsInternalizedString()) return Smi::FromInt(0);
-  if (type == STRING_SPLIT_SUBSTRINGS) {
-    DCHECK(key_pattern->IsString());
-    if (!key_pattern->IsInternalizedString()) return Smi::FromInt(0);
-    cache = heap->string_split_cache();
-  } else {
-    DCHECK(type == REGEXP_MULTIPLE_INDICES);
-    DCHECK(key_pattern->IsFixedArray());
-    cache = heap->regexp_multiple_cache();
-  }
-
-  uint32_t hash = key_string->Hash();
-  uint32_t index = ((hash & (kRegExpResultsCacheSize - 1)) &
-      ~(kArrayEntriesPerCacheEntry - 1));
-  if (cache->get(index + kStringOffset) == key_string &&
-      cache->get(index + kPatternOffset) == key_pattern) {
-    return cache->get(index + kArrayOffset);
-  }
-  index =
-      ((index + kArrayEntriesPerCacheEntry) & (kRegExpResultsCacheSize - 1));
-  if (cache->get(index + kStringOffset) == key_string &&
-      cache->get(index + kPatternOffset) == key_pattern) {
-    return cache->get(index + kArrayOffset);
-  }
-  return Smi::FromInt(0);
-}
-
-
-void RegExpResultsCache::Enter(Isolate* isolate,
-                               Handle<String> key_string,
-                               Handle<Object> key_pattern,
-                               Handle<FixedArray> value_array,
-                               ResultsCacheType type) {
-  Factory* factory = isolate->factory();
-  Handle<FixedArray> cache;
-  if (!key_string->IsInternalizedString()) return;
-  if (type == STRING_SPLIT_SUBSTRINGS) {
-    DCHECK(key_pattern->IsString());
-    if (!key_pattern->IsInternalizedString()) return;
-    cache = factory->string_split_cache();
-  } else {
-    DCHECK(type == REGEXP_MULTIPLE_INDICES);
-    DCHECK(key_pattern->IsFixedArray());
-    cache = factory->regexp_multiple_cache();
-  }
-
-  uint32_t hash = key_string->Hash();
-  uint32_t index = ((hash & (kRegExpResultsCacheSize - 1)) &
-      ~(kArrayEntriesPerCacheEntry - 1));
-  if (cache->get(index + kStringOffset) == Smi::FromInt(0)) {
-    cache->set(index + kStringOffset, *key_string);
-    cache->set(index + kPatternOffset, *key_pattern);
-    cache->set(index + kArrayOffset, *value_array);
-  } else {
-    uint32_t index2 =
-        ((index + kArrayEntriesPerCacheEntry) & (kRegExpResultsCacheSize - 1));
-    if (cache->get(index2 + kStringOffset) == Smi::FromInt(0)) {
-      cache->set(index2 + kStringOffset, *key_string);
-      cache->set(index2 + kPatternOffset, *key_pattern);
-      cache->set(index2 + kArrayOffset, *value_array);
-    } else {
-      cache->set(index2 + kStringOffset, Smi::FromInt(0));
-      cache->set(index2 + kPatternOffset, Smi::FromInt(0));
-      cache->set(index2 + kArrayOffset, Smi::FromInt(0));
-      cache->set(index + kStringOffset, *key_string);
-      cache->set(index + kPatternOffset, *key_pattern);
-      cache->set(index + kArrayOffset, *value_array);
-    }
-  }
-  // If the array is a reasonably short list of substrings, convert it into a
-  // list of internalized strings.
-  if (type == STRING_SPLIT_SUBSTRINGS && value_array->length() < 100) {
-    for (int i = 0; i < value_array->length(); i++) {
-      Handle<String> str(String::cast(value_array->get(i)), isolate);
-      Handle<String> internalized_str = factory->InternalizeString(str);
-      value_array->set(i, *internalized_str);
-    }
-  }
-  // Convert backing store to a copy-on-write array.
-  value_array->set_map_no_write_barrier(*factory->fixed_cow_array_map());
-}
-
-
-void RegExpResultsCache::Clear(FixedArray* cache) {
-  for (int i = 0; i < kRegExpResultsCacheSize; i++) {
-    cache->set(i, Smi::FromInt(0));
-  }
-}
-
-
-int Heap::FullSizeNumberStringCacheLength() {
-  // Compute the size of the number string cache based on the max newspace size.
-  // The number string cache has a minimum size based on twice the initial cache
-  // size to ensure that it is bigger after being made 'full size'.
-  int number_string_cache_size = max_semi_space_size_ / 512;
-  number_string_cache_size = Max(kInitialNumberStringCacheSize * 2,
-                                 Min(0x4000, number_string_cache_size));
-  // There is a string and a number per entry so the length is twice the number
-  // of entries.
-  return number_string_cache_size * 2;
-}
-
-
-void Heap::FlushNumberStringCache() {
-  // Flush the number to string cache.
-  int len = number_string_cache()->length();
-  for (int i = 0; i < len; i++) {
-    number_string_cache()->set_undefined(i);
-  }
-}
-
-
-void Heap::FlushAllocationSitesScratchpad() {
-  for (int i = 0; i < allocation_sites_scratchpad_length_; i++) {
-    allocation_sites_scratchpad()->set_undefined(i);
-  }
-  allocation_sites_scratchpad_length_ = 0;
-}
-
-
-void Heap::InitializeAllocationSitesScratchpad() {
-  DCHECK(allocation_sites_scratchpad()->length() ==
-         kAllocationSiteScratchpadSize);
-  for (int i = 0; i < kAllocationSiteScratchpadSize; i++) {
-    allocation_sites_scratchpad()->set_undefined(i);
-  }
-}
-
-
-void Heap::AddAllocationSiteToScratchpad(AllocationSite* site,
-                                         ScratchpadSlotMode mode) {
-  if (allocation_sites_scratchpad_length_ < kAllocationSiteScratchpadSize) {
-    // We cannot use the normal write-barrier because slots need to be
-    // recorded with non-incremental marking as well. We have to explicitly
-    // record the slot to take evacuation candidates into account.
-    allocation_sites_scratchpad()->set(
-        allocation_sites_scratchpad_length_, site, SKIP_WRITE_BARRIER);
-    Object** slot = allocation_sites_scratchpad()->RawFieldOfElementAt(
-        allocation_sites_scratchpad_length_);
-
-    if (mode == RECORD_SCRATCHPAD_SLOT) {
-      // We need to allow slots buffer overflow here since the evacuation
-      // candidates are not part of the global list of old space pages and
-      // releasing an evacuation candidate due to a slots buffer overflow
-      // results in lost pages.
-      mark_compact_collector()->RecordSlot(
-          slot, slot, *slot, SlotsBuffer::IGNORE_OVERFLOW);
-    }
-    allocation_sites_scratchpad_length_++;
-  }
-}
-
-
-Map* Heap::MapForExternalArrayType(ExternalArrayType array_type) {
-  return Map::cast(roots_[RootIndexForExternalArrayType(array_type)]);
-}
-
-
-Heap::RootListIndex Heap::RootIndexForExternalArrayType(
-    ExternalArrayType array_type) {
-  switch (array_type) {
-#define ARRAY_TYPE_TO_ROOT_INDEX(Type, type, TYPE, ctype, size)               \
-    case kExternal##Type##Array:                                              \
-      return kExternal##Type##ArrayMapRootIndex;
-
-    TYPED_ARRAYS(ARRAY_TYPE_TO_ROOT_INDEX)
-#undef ARRAY_TYPE_TO_ROOT_INDEX
-
-    default:
-      UNREACHABLE();
-      return kUndefinedValueRootIndex;
-  }
-}
-
-
-Map* Heap::MapForFixedTypedArray(ExternalArrayType array_type) {
-  return Map::cast(roots_[RootIndexForFixedTypedArray(array_type)]);
-}
-
-
-Heap::RootListIndex Heap::RootIndexForFixedTypedArray(
-    ExternalArrayType array_type) {
-  switch (array_type) {
-#define ARRAY_TYPE_TO_ROOT_INDEX(Type, type, TYPE, ctype, size)               \
-    case kExternal##Type##Array:                                              \
-      return kFixed##Type##ArrayMapRootIndex;
-
-    TYPED_ARRAYS(ARRAY_TYPE_TO_ROOT_INDEX)
-#undef ARRAY_TYPE_TO_ROOT_INDEX
-
-    default:
-      UNREACHABLE();
-      return kUndefinedValueRootIndex;
-  }
-}
-
-
-Heap::RootListIndex Heap::RootIndexForEmptyExternalArray(
-    ElementsKind elementsKind) {
-  switch (elementsKind) {
-#define ELEMENT_KIND_TO_ROOT_INDEX(Type, type, TYPE, ctype, size)             \
-    case EXTERNAL_##TYPE##_ELEMENTS:                                          \
-      return kEmptyExternal##Type##ArrayRootIndex;
-
-    TYPED_ARRAYS(ELEMENT_KIND_TO_ROOT_INDEX)
-#undef ELEMENT_KIND_TO_ROOT_INDEX
-
-    default:
-      UNREACHABLE();
-      return kUndefinedValueRootIndex;
-  }
-}
-
-
-Heap::RootListIndex Heap::RootIndexForEmptyFixedTypedArray(
-    ElementsKind elementsKind) {
-  switch (elementsKind) {
-#define ELEMENT_KIND_TO_ROOT_INDEX(Type, type, TYPE, ctype, size)             \
-    case TYPE##_ELEMENTS:                                                     \
-      return kEmptyFixed##Type##ArrayRootIndex;
-
-    TYPED_ARRAYS(ELEMENT_KIND_TO_ROOT_INDEX)
-#undef ELEMENT_KIND_TO_ROOT_INDEX
-    default:
-      UNREACHABLE();
-      return kUndefinedValueRootIndex;
-  }
-}
-
-
-ExternalArray* Heap::EmptyExternalArrayForMap(Map* map) {
-  return ExternalArray::cast(
-      roots_[RootIndexForEmptyExternalArray(map->elements_kind())]);
-}
-
-
-FixedTypedArrayBase* Heap::EmptyFixedTypedArrayForMap(Map* map) {
-  return FixedTypedArrayBase::cast(
-      roots_[RootIndexForEmptyFixedTypedArray(map->elements_kind())]);
-}
-
-
-AllocationResult Heap::AllocateForeign(Address address,
-                                       PretenureFlag pretenure) {
-  // Statically ensure that it is safe to allocate foreigns in paged spaces.
-  STATIC_ASSERT(Foreign::kSize <= Page::kMaxRegularHeapObjectSize);
-  AllocationSpace space = (pretenure == TENURED) ? OLD_DATA_SPACE : NEW_SPACE;
-  Foreign* result;
-  AllocationResult allocation = Allocate(foreign_map(), space);
-  if (!allocation.To(&result)) return allocation;
-  result->set_foreign_address(address);
-  return result;
-}
-
-
-AllocationResult Heap::AllocateByteArray(int length, PretenureFlag pretenure) {
-  if (length < 0 || length > ByteArray::kMaxLength) {
-    v8::internal::Heap::FatalProcessOutOfMemory("invalid array length", true);
-  }
-  int size = ByteArray::SizeFor(length);
-  AllocationSpace space = SelectSpace(size, OLD_DATA_SPACE, pretenure);
-  HeapObject* result;
-  { AllocationResult allocation = AllocateRaw(size, space, OLD_DATA_SPACE);
-    if (!allocation.To(&result)) return allocation;
-  }
-
-  result->set_map_no_write_barrier(byte_array_map());
-  ByteArray::cast(result)->set_length(length);
-  return result;
-}
-
-
-void Heap::CreateFillerObjectAt(Address addr, int size) {
-  if (size == 0) return;
-  HeapObject* filler = HeapObject::FromAddress(addr);
-  if (size == kPointerSize) {
-    filler->set_map_no_write_barrier(one_pointer_filler_map());
-  } else if (size == 2 * kPointerSize) {
-    filler->set_map_no_write_barrier(two_pointer_filler_map());
-  } else {
-    filler->set_map_no_write_barrier(free_space_map());
-    FreeSpace::cast(filler)->set_size(size);
-  }
-}
-
-
-bool Heap::CanMoveObjectStart(HeapObject* object) {
-  Address address = object->address();
-  bool is_in_old_pointer_space = InOldPointerSpace(address);
-  bool is_in_old_data_space = InOldDataSpace(address);
-
-  if (lo_space()->Contains(object)) return false;
-
-  Page* page = Page::FromAddress(address);
-  // We can move the object start if:
-  // (1) the object is not in old pointer or old data space,
-  // (2) the page of the object was already swept,
-  // (3) the page was already concurrently swept. This case is an optimization
-  // for concurrent sweeping. The WasSwept predicate for concurrently swept
-  // pages is set after sweeping all pages.
-  return (!is_in_old_pointer_space && !is_in_old_data_space) ||
-         page->WasSwept() || page->SweepingCompleted();
-}
-
-
-void Heap::AdjustLiveBytes(Address address, int by, InvocationMode mode) {
-  if (incremental_marking()->IsMarking() &&
-      Marking::IsBlack(Marking::MarkBitFrom(address))) {
-    if (mode == FROM_GC) {
-      MemoryChunk::IncrementLiveBytesFromGC(address, by);
-    } else {
-      MemoryChunk::IncrementLiveBytesFromMutator(address, by);
-    }
-  }
-}
-
-
-AllocationResult Heap::AllocateExternalArray(int length,
-                                         ExternalArrayType array_type,
-                                         void* external_pointer,
-                                         PretenureFlag pretenure) {
-  int size = ExternalArray::kAlignedSize;
-  AllocationSpace space = SelectSpace(size, OLD_DATA_SPACE, pretenure);
-  HeapObject* result;
-  { AllocationResult allocation = AllocateRaw(size, space, OLD_DATA_SPACE);
-    if (!allocation.To(&result)) return allocation;
-  }
-
-  result->set_map_no_write_barrier(
-      MapForExternalArrayType(array_type));
-  ExternalArray::cast(result)->set_length(length);
-  ExternalArray::cast(result)->set_external_pointer(external_pointer);
-  return result;
-}
-
-static void ForFixedTypedArray(ExternalArrayType array_type,
-                               int* element_size,
-                               ElementsKind* element_kind) {
-  switch (array_type) {
-#define TYPED_ARRAY_CASE(Type, type, TYPE, ctype, size)                       \
-    case kExternal##Type##Array:                                              \
-      *element_size = size;                                                   \
-      *element_kind = TYPE##_ELEMENTS;                                        \
-      return;
-
-    TYPED_ARRAYS(TYPED_ARRAY_CASE)
-#undef TYPED_ARRAY_CASE
-
-    default:
-      *element_size = 0;  // Bogus
-      *element_kind = UINT8_ELEMENTS;  // Bogus
-      UNREACHABLE();
-  }
-}
-
-
-AllocationResult Heap::AllocateFixedTypedArray(int length,
-                                               ExternalArrayType array_type,
-                                               PretenureFlag pretenure) {
-  int element_size;
-  ElementsKind elements_kind;
-  ForFixedTypedArray(array_type, &element_size, &elements_kind);
-  int size = OBJECT_POINTER_ALIGN(
-      length * element_size + FixedTypedArrayBase::kDataOffset);
-#ifndef V8_HOST_ARCH_64_BIT
-  if (array_type == kExternalFloat64Array) {
-    size += kPointerSize;
-  }
-#endif
-  AllocationSpace space = SelectSpace(size, OLD_DATA_SPACE, pretenure);
-
-  HeapObject* object;
-  AllocationResult allocation = AllocateRaw(size, space, OLD_DATA_SPACE);
-  if (!allocation.To(&object)) return allocation;
-
-  if (array_type == kExternalFloat64Array) {
-    object = EnsureDoubleAligned(this, object, size);
-  }
-
-  object->set_map(MapForFixedTypedArray(array_type));
-  FixedTypedArrayBase* elements = FixedTypedArrayBase::cast(object);
-  elements->set_length(length);
-  memset(elements->DataPtr(), 0, elements->DataSize());
-  return elements;
-}
-
-
-AllocationResult Heap::AllocateCode(int object_size, bool immovable) {
-  DCHECK(IsAligned(static_cast<intptr_t>(object_size), kCodeAlignment));
-  AllocationResult allocation =
-      AllocateRaw(object_size, CODE_SPACE, CODE_SPACE);
-
-  HeapObject* result;
-  if (!allocation.To(&result)) return allocation;
-
-  if (immovable) {
-    Address address = result->address();
-    // Code objects which should stay at a fixed address are allocated either
-    // in the first page of code space (objects on the first page of each space
-    // are never moved) or in large object space.
-    if (!code_space_->FirstPage()->Contains(address) &&
-        MemoryChunk::FromAddress(address)->owner()->identity() != LO_SPACE) {
-      // Discard the first code allocation, which was on a page where it could
-      // be moved.
-      CreateFillerObjectAt(result->address(), object_size);
-      allocation = lo_space_->AllocateRaw(object_size, EXECUTABLE);
-      if (!allocation.To(&result)) return allocation;
-      OnAllocationEvent(result, object_size);
-    }
-  }
-
-  result->set_map_no_write_barrier(code_map());
-  Code* code = Code::cast(result);
-  DCHECK(isolate_->code_range() == NULL ||
-         !isolate_->code_range()->valid() ||
-         isolate_->code_range()->contains(code->address()));
-  code->set_gc_metadata(Smi::FromInt(0));
-  code->set_ic_age(global_ic_age_);
-  return code;
-}
-
-
-AllocationResult Heap::CopyCode(Code* code) {
-  AllocationResult allocation;
-  HeapObject* new_constant_pool;
-  if (FLAG_enable_ool_constant_pool &&
-      code->constant_pool() != empty_constant_pool_array()) {
-    // Copy the constant pool, since edits to the copied code may modify
-    // the constant pool.
-    allocation = CopyConstantPoolArray(code->constant_pool());
-    if (!allocation.To(&new_constant_pool)) return allocation;
-  } else {
-    new_constant_pool = empty_constant_pool_array();
-  }
-
-  HeapObject* result;
-  // Allocate an object the same size as the code object.
-  int obj_size = code->Size();
-  allocation = AllocateRaw(obj_size, CODE_SPACE, CODE_SPACE);
-  if (!allocation.To(&result)) return allocation;
-
-  // Copy code object.
-  Address old_addr = code->address();
-  Address new_addr = result->address();
-  CopyBlock(new_addr, old_addr, obj_size);
-  Code* new_code = Code::cast(result);
-
-  // Update the constant pool.
-  new_code->set_constant_pool(new_constant_pool);
-
-  // Relocate the copy.
-  DCHECK(isolate_->code_range() == NULL ||
-         !isolate_->code_range()->valid() ||
-         isolate_->code_range()->contains(code->address()));
-  new_code->Relocate(new_addr - old_addr);
-  return new_code;
-}
-
-
-AllocationResult Heap::CopyCode(Code* code, Vector<byte> reloc_info) {
-  // Allocate ByteArray and ConstantPoolArray before the Code object, so that we
-  // do not risk leaving uninitialized Code object (and breaking the heap).
-  ByteArray* reloc_info_array;
-  { AllocationResult allocation =
-        AllocateByteArray(reloc_info.length(), TENURED);
-    if (!allocation.To(&reloc_info_array)) return allocation;
-  }
-  HeapObject* new_constant_pool;
-  if (FLAG_enable_ool_constant_pool &&
-      code->constant_pool() != empty_constant_pool_array()) {
-    // Copy the constant pool, since edits to the copied code may modify
-    // the constant pool.
-    AllocationResult allocation =
-        CopyConstantPoolArray(code->constant_pool());
-    if (!allocation.To(&new_constant_pool)) return allocation;
-  } else {
-    new_constant_pool = empty_constant_pool_array();
-  }
-
-  int new_body_size = RoundUp(code->instruction_size(), kObjectAlignment);
-
-  int new_obj_size = Code::SizeFor(new_body_size);
-
-  Address old_addr = code->address();
-
-  size_t relocation_offset =
-      static_cast<size_t>(code->instruction_end() - old_addr);
-
-  HeapObject* result;
-  AllocationResult allocation =
-      AllocateRaw(new_obj_size, CODE_SPACE, CODE_SPACE);
-  if (!allocation.To(&result)) return allocation;
-
-  // Copy code object.
-  Address new_addr = result->address();
-
-  // Copy header and instructions.
-  CopyBytes(new_addr, old_addr, relocation_offset);
-
-  Code* new_code = Code::cast(result);
-  new_code->set_relocation_info(reloc_info_array);
-
-  // Update constant pool.
-  new_code->set_constant_pool(new_constant_pool);
-
-  // Copy patched rinfo.
-  CopyBytes(new_code->relocation_start(),
-            reloc_info.start(),
-            static_cast<size_t>(reloc_info.length()));
-
-  // Relocate the copy.
-  DCHECK(isolate_->code_range() == NULL ||
-         !isolate_->code_range()->valid() ||
-         isolate_->code_range()->contains(code->address()));
-  new_code->Relocate(new_addr - old_addr);
-
-#ifdef VERIFY_HEAP
-  if (FLAG_verify_heap) code->ObjectVerify();
-#endif
-  return new_code;
-}
-
-
-void Heap::InitializeAllocationMemento(AllocationMemento* memento,
-                                       AllocationSite* allocation_site) {
-  memento->set_map_no_write_barrier(allocation_memento_map());
-  DCHECK(allocation_site->map() == allocation_site_map());
-  memento->set_allocation_site(allocation_site, SKIP_WRITE_BARRIER);
-  if (FLAG_allocation_site_pretenuring) {
-    allocation_site->IncrementMementoCreateCount();
-  }
-}
-
-
-AllocationResult Heap::Allocate(Map* map, AllocationSpace space,
-                            AllocationSite* allocation_site) {
-  DCHECK(gc_state_ == NOT_IN_GC);
-  DCHECK(map->instance_type() != MAP_TYPE);
-  // If allocation failures are disallowed, we may allocate in a different
-  // space when new space is full and the object is not a large object.
-  AllocationSpace retry_space =
-      (space != NEW_SPACE) ? space : TargetSpaceId(map->instance_type());
-  int size = map->instance_size();
-  if (allocation_site != NULL) {
-    size += AllocationMemento::kSize;
-  }
-  HeapObject* result;
-  AllocationResult allocation = AllocateRaw(size, space, retry_space);
-  if (!allocation.To(&result)) return allocation;
-  // No need for write barrier since object is white and map is in old space.
-  result->set_map_no_write_barrier(map);
-  if (allocation_site != NULL) {
-    AllocationMemento* alloc_memento = reinterpret_cast<AllocationMemento*>(
-        reinterpret_cast<Address>(result) + map->instance_size());
-    InitializeAllocationMemento(alloc_memento, allocation_site);
-  }
-  return result;
-}
-
-
-void Heap::InitializeJSObjectFromMap(JSObject* obj,
-                                     FixedArray* properties,
-                                     Map* map) {
-  obj->set_properties(properties);
-  obj->initialize_elements();
-  // TODO(1240798): Initialize the object's body using valid initial values
-  // according to the object's initial map.  For example, if the map's
-  // instance type is JS_ARRAY_TYPE, the length field should be initialized
-  // to a number (e.g. Smi::FromInt(0)) and the elements initialized to a
-  // fixed array (e.g. Heap::empty_fixed_array()).  Currently, the object
-  // verification code has to cope with (temporarily) invalid objects.  See
-  // for example, JSArray::JSArrayVerify).
-  Object* filler;
-  // We cannot always fill with one_pointer_filler_map because objects
-  // created from API functions expect their internal fields to be initialized
-  // with undefined_value.
-  // Pre-allocated fields need to be initialized with undefined_value as well
-  // so that object accesses before the constructor completes (e.g. in the
-  // debugger) will not cause a crash.
-  if (map->constructor()->IsJSFunction() &&
-      JSFunction::cast(map->constructor())->
-          IsInobjectSlackTrackingInProgress()) {
-    // We might want to shrink the object later.
-    DCHECK(obj->GetInternalFieldCount() == 0);
-    filler = Heap::one_pointer_filler_map();
-  } else {
-    filler = Heap::undefined_value();
-  }
-  obj->InitializeBody(map, Heap::undefined_value(), filler);
-}
-
-
-AllocationResult Heap::AllocateJSObjectFromMap(
-    Map* map,
-    PretenureFlag pretenure,
-    bool allocate_properties,
-    AllocationSite* allocation_site) {
-  // JSFunctions should be allocated using AllocateFunction to be
-  // properly initialized.
-  DCHECK(map->instance_type() != JS_FUNCTION_TYPE);
-
-  // Both types of global objects should be allocated using
-  // AllocateGlobalObject to be properly initialized.
-  DCHECK(map->instance_type() != JS_GLOBAL_OBJECT_TYPE);
-  DCHECK(map->instance_type() != JS_BUILTINS_OBJECT_TYPE);
-
-  // Allocate the backing storage for the properties.
-  FixedArray* properties;
-  if (allocate_properties) {
-    int prop_size = map->InitialPropertiesLength();
-    DCHECK(prop_size >= 0);
-    { AllocationResult allocation = AllocateFixedArray(prop_size, pretenure);
-      if (!allocation.To(&properties)) return allocation;
-    }
-  } else {
-    properties = empty_fixed_array();
-  }
-
-  // Allocate the JSObject.
-  int size = map->instance_size();
-  AllocationSpace space = SelectSpace(size, OLD_POINTER_SPACE, pretenure);
-  JSObject* js_obj;
-  AllocationResult allocation = Allocate(map, space, allocation_site);
-  if (!allocation.To(&js_obj)) return allocation;
-
-  // Initialize the JSObject.
-  InitializeJSObjectFromMap(js_obj, properties, map);
-  DCHECK(js_obj->HasFastElements() ||
-         js_obj->HasExternalArrayElements() ||
-         js_obj->HasFixedTypedArrayElements());
-  return js_obj;
-}
-
-
-AllocationResult Heap::AllocateJSObject(JSFunction* constructor,
-                                        PretenureFlag pretenure,
-                                        AllocationSite* allocation_site) {
-  DCHECK(constructor->has_initial_map());
-
-  // Allocate the object based on the constructors initial map.
-  AllocationResult allocation = AllocateJSObjectFromMap(
-      constructor->initial_map(), pretenure, true, allocation_site);
-#ifdef DEBUG
-  // Make sure result is NOT a global object if valid.
-  HeapObject* obj;
-  DCHECK(!allocation.To(&obj) || !obj->IsGlobalObject());
-#endif
-  return allocation;
-}
-
-
-AllocationResult Heap::CopyJSObject(JSObject* source, AllocationSite* site) {
-  // Never used to copy functions.  If functions need to be copied we
-  // have to be careful to clear the literals array.
-  SLOW_DCHECK(!source->IsJSFunction());
-
-  // Make the clone.
-  Map* map = source->map();
-  int object_size = map->instance_size();
-  HeapObject* clone;
-
-  DCHECK(site == NULL || AllocationSite::CanTrack(map->instance_type()));
-
-  WriteBarrierMode wb_mode = UPDATE_WRITE_BARRIER;
-
-  // If we're forced to always allocate, we use the general allocation
-  // functions which may leave us with an object in old space.
-  if (always_allocate()) {
-    { AllocationResult allocation =
-          AllocateRaw(object_size, NEW_SPACE, OLD_POINTER_SPACE);
-      if (!allocation.To(&clone)) return allocation;
-    }
-    Address clone_address = clone->address();
-    CopyBlock(clone_address,
-              source->address(),
-              object_size);
-    // Update write barrier for all fields that lie beyond the header.
-    RecordWrites(clone_address,
-                 JSObject::kHeaderSize,
-                 (object_size - JSObject::kHeaderSize) / kPointerSize);
-  } else {
-    wb_mode = SKIP_WRITE_BARRIER;
-
-    { int adjusted_object_size = site != NULL
-          ? object_size + AllocationMemento::kSize
-          : object_size;
-    AllocationResult allocation =
-          AllocateRaw(adjusted_object_size, NEW_SPACE, NEW_SPACE);
-      if (!allocation.To(&clone)) return allocation;
-    }
-    SLOW_DCHECK(InNewSpace(clone));
-    // Since we know the clone is allocated in new space, we can copy
-    // the contents without worrying about updating the write barrier.
-    CopyBlock(clone->address(),
-              source->address(),
-              object_size);
-
-    if (site != NULL) {
-      AllocationMemento* alloc_memento = reinterpret_cast<AllocationMemento*>(
-          reinterpret_cast<Address>(clone) + object_size);
-      InitializeAllocationMemento(alloc_memento, site);
-    }
-  }
-
-  SLOW_DCHECK(
-      JSObject::cast(clone)->GetElementsKind() == source->GetElementsKind());
-  FixedArrayBase* elements = FixedArrayBase::cast(source->elements());
-  FixedArray* properties = FixedArray::cast(source->properties());
-  // Update elements if necessary.
-  if (elements->length() > 0) {
-    FixedArrayBase* elem;
-    { AllocationResult allocation;
-      if (elements->map() == fixed_cow_array_map()) {
-        allocation = FixedArray::cast(elements);
-      } else if (source->HasFastDoubleElements()) {
-        allocation = CopyFixedDoubleArray(FixedDoubleArray::cast(elements));
-      } else {
-        allocation = CopyFixedArray(FixedArray::cast(elements));
-      }
-      if (!allocation.To(&elem)) return allocation;
-    }
-    JSObject::cast(clone)->set_elements(elem, wb_mode);
-  }
-  // Update properties if necessary.
-  if (properties->length() > 0) {
-    FixedArray* prop;
-    { AllocationResult allocation = CopyFixedArray(properties);
-      if (!allocation.To(&prop)) return allocation;
-    }
-    JSObject::cast(clone)->set_properties(prop, wb_mode);
-  }
-  // Return the new clone.
-  return clone;
-}
-
-
-static inline void WriteOneByteData(Vector<const char> vector,
-                                    uint8_t* chars,
-                                    int len) {
-  // Only works for ascii.
-  DCHECK(vector.length() == len);
-  MemCopy(chars, vector.start(), len);
-}
-
-static inline void WriteTwoByteData(Vector<const char> vector,
-                                    uint16_t* chars,
-                                    int len) {
-  const uint8_t* stream = reinterpret_cast<const uint8_t*>(vector.start());
-  unsigned stream_length = vector.length();
-  while (stream_length != 0) {
-    unsigned consumed = 0;
-    uint32_t c = unibrow::Utf8::ValueOf(stream, stream_length, &consumed);
-    DCHECK(c != unibrow::Utf8::kBadChar);
-    DCHECK(consumed <= stream_length);
-    stream_length -= consumed;
-    stream += consumed;
-    if (c > unibrow::Utf16::kMaxNonSurrogateCharCode) {
-      len -= 2;
-      if (len < 0) break;
-      *chars++ = unibrow::Utf16::LeadSurrogate(c);
-      *chars++ = unibrow::Utf16::TrailSurrogate(c);
-    } else {
-      len -= 1;
-      if (len < 0) break;
-      *chars++ = c;
-    }
-  }
-  DCHECK(stream_length == 0);
-  DCHECK(len == 0);
-}
-
-
-static inline void WriteOneByteData(String* s, uint8_t* chars, int len) {
-  DCHECK(s->length() == len);
-  String::WriteToFlat(s, chars, 0, len);
-}
-
-
-static inline void WriteTwoByteData(String* s, uint16_t* chars, int len) {
-  DCHECK(s->length() == len);
-  String::WriteToFlat(s, chars, 0, len);
-}
-
-
-template<bool is_one_byte, typename T>
-AllocationResult Heap::AllocateInternalizedStringImpl(
-    T t, int chars, uint32_t hash_field) {
-  DCHECK(chars >= 0);
-  // Compute map and object size.
-  int size;
-  Map* map;
-
-  DCHECK_LE(0, chars);
-  DCHECK_GE(String::kMaxLength, chars);
-  if (is_one_byte) {
-    map = ascii_internalized_string_map();
-    size = SeqOneByteString::SizeFor(chars);
-  } else {
-    map = internalized_string_map();
-    size = SeqTwoByteString::SizeFor(chars);
-  }
-  AllocationSpace space = SelectSpace(size, OLD_DATA_SPACE, TENURED);
-
-  // Allocate string.
-  HeapObject* result;
-  { AllocationResult allocation = AllocateRaw(size, space, OLD_DATA_SPACE);
-    if (!allocation.To(&result)) return allocation;
-  }
-
-  result->set_map_no_write_barrier(map);
-  // Set length and hash fields of the allocated string.
-  String* answer = String::cast(result);
-  answer->set_length(chars);
-  answer->set_hash_field(hash_field);
-
-  DCHECK_EQ(size, answer->Size());
-
-  if (is_one_byte) {
-    WriteOneByteData(t, SeqOneByteString::cast(answer)->GetChars(), chars);
-  } else {
-    WriteTwoByteData(t, SeqTwoByteString::cast(answer)->GetChars(), chars);
-  }
-  return answer;
-}
-
-
-// Need explicit instantiations.
-template
-AllocationResult Heap::AllocateInternalizedStringImpl<true>(
-    String*, int, uint32_t);
-template
-AllocationResult Heap::AllocateInternalizedStringImpl<false>(
-    String*, int, uint32_t);
-template
-AllocationResult Heap::AllocateInternalizedStringImpl<false>(
-    Vector<const char>, int, uint32_t);
-
-
-AllocationResult Heap::AllocateRawOneByteString(int length,
-                                                PretenureFlag pretenure) {
-  DCHECK_LE(0, length);
-  DCHECK_GE(String::kMaxLength, length);
-  int size = SeqOneByteString::SizeFor(length);
-  DCHECK(size <= SeqOneByteString::kMaxSize);
-  AllocationSpace space = SelectSpace(size, OLD_DATA_SPACE, pretenure);
-
-  HeapObject* result;
-  { AllocationResult allocation = AllocateRaw(size, space, OLD_DATA_SPACE);
-    if (!allocation.To(&result)) return allocation;
-  }
-
-  // Partially initialize the object.
-  result->set_map_no_write_barrier(ascii_string_map());
-  String::cast(result)->set_length(length);
-  String::cast(result)->set_hash_field(String::kEmptyHashField);
-  DCHECK_EQ(size, HeapObject::cast(result)->Size());
-
-  return result;
-}
-
-
-AllocationResult Heap::AllocateRawTwoByteString(int length,
-                                                PretenureFlag pretenure) {
-  DCHECK_LE(0, length);
-  DCHECK_GE(String::kMaxLength, length);
-  int size = SeqTwoByteString::SizeFor(length);
-  DCHECK(size <= SeqTwoByteString::kMaxSize);
-  AllocationSpace space = SelectSpace(size, OLD_DATA_SPACE, pretenure);
-
-  HeapObject* result;
-  { AllocationResult allocation = AllocateRaw(size, space, OLD_DATA_SPACE);
-    if (!allocation.To(&result)) return allocation;
-  }
-
-  // Partially initialize the object.
-  result->set_map_no_write_barrier(string_map());
-  String::cast(result)->set_length(length);
-  String::cast(result)->set_hash_field(String::kEmptyHashField);
-  DCHECK_EQ(size, HeapObject::cast(result)->Size());
-  return result;
-}
-
-
-AllocationResult Heap::AllocateEmptyFixedArray() {
-  int size = FixedArray::SizeFor(0);
-  HeapObject* result;
-  { AllocationResult allocation =
-        AllocateRaw(size, OLD_DATA_SPACE, OLD_DATA_SPACE);
-    if (!allocation.To(&result)) return allocation;
-  }
-  // Initialize the object.
-  result->set_map_no_write_barrier(fixed_array_map());
-  FixedArray::cast(result)->set_length(0);
-  return result;
-}
-
-
-AllocationResult Heap::AllocateEmptyExternalArray(
-    ExternalArrayType array_type) {
-  return AllocateExternalArray(0, array_type, NULL, TENURED);
-}
-
-
-AllocationResult Heap::CopyAndTenureFixedCOWArray(FixedArray* src) {
-  if (!InNewSpace(src)) {
-    return src;
-  }
-
-  int len = src->length();
-  HeapObject* obj;
-  { AllocationResult allocation = AllocateRawFixedArray(len, TENURED);
-    if (!allocation.To(&obj)) return allocation;
-  }
-  obj->set_map_no_write_barrier(fixed_array_map());
-  FixedArray* result = FixedArray::cast(obj);
-  result->set_length(len);
-
-  // Copy the content
-  DisallowHeapAllocation no_gc;
-  WriteBarrierMode mode = result->GetWriteBarrierMode(no_gc);
-  for (int i = 0; i < len; i++) result->set(i, src->get(i), mode);
-
-  // TODO(mvstanton): The map is set twice because of protection against calling
-  // set() on a COW FixedArray. Issue v8:3221 created to track this, and
-  // we might then be able to remove this whole method.
-  HeapObject::cast(obj)->set_map_no_write_barrier(fixed_cow_array_map());
-  return result;
-}
-
-
-AllocationResult Heap::AllocateEmptyFixedTypedArray(
-    ExternalArrayType array_type) {
-  return AllocateFixedTypedArray(0, array_type, TENURED);
-}
-
-
-AllocationResult Heap::CopyFixedArrayWithMap(FixedArray* src, Map* map) {
-  int len = src->length();
-  HeapObject* obj;
-  { AllocationResult allocation = AllocateRawFixedArray(len, NOT_TENURED);
-    if (!allocation.To(&obj)) return allocation;
-  }
-  if (InNewSpace(obj)) {
-    obj->set_map_no_write_barrier(map);
-    CopyBlock(obj->address() + kPointerSize,
-              src->address() + kPointerSize,
-              FixedArray::SizeFor(len) - kPointerSize);
-    return obj;
-  }
-  obj->set_map_no_write_barrier(map);
-  FixedArray* result = FixedArray::cast(obj);
-  result->set_length(len);
-
-  // Copy the content
-  DisallowHeapAllocation no_gc;
-  WriteBarrierMode mode = result->GetWriteBarrierMode(no_gc);
-  for (int i = 0; i < len; i++) result->set(i, src->get(i), mode);
-  return result;
-}
-
-
-AllocationResult Heap::CopyFixedDoubleArrayWithMap(FixedDoubleArray* src,
-                                                   Map* map) {
-  int len = src->length();
-  HeapObject* obj;
-  { AllocationResult allocation = AllocateRawFixedDoubleArray(len, NOT_TENURED);
-    if (!allocation.To(&obj)) return allocation;
-  }
-  obj->set_map_no_write_barrier(map);
-  CopyBlock(
-      obj->address() + FixedDoubleArray::kLengthOffset,
-      src->address() + FixedDoubleArray::kLengthOffset,
-      FixedDoubleArray::SizeFor(len) - FixedDoubleArray::kLengthOffset);
-  return obj;
-}
-
-
-AllocationResult Heap::CopyConstantPoolArrayWithMap(ConstantPoolArray* src,
-                                                    Map* map) {
-  HeapObject* obj;
-  if (src->is_extended_layout()) {
-    ConstantPoolArray::NumberOfEntries small(src,
-        ConstantPoolArray::SMALL_SECTION);
-    ConstantPoolArray::NumberOfEntries extended(src,
-        ConstantPoolArray::EXTENDED_SECTION);
-    AllocationResult allocation =
-        AllocateExtendedConstantPoolArray(small, extended);
-    if (!allocation.To(&obj)) return allocation;
-  } else {
-    ConstantPoolArray::NumberOfEntries small(src,
-        ConstantPoolArray::SMALL_SECTION);
-    AllocationResult allocation = AllocateConstantPoolArray(small);
-    if (!allocation.To(&obj)) return allocation;
-  }
-  obj->set_map_no_write_barrier(map);
-  CopyBlock(
-      obj->address() + ConstantPoolArray::kFirstEntryOffset,
-      src->address() + ConstantPoolArray::kFirstEntryOffset,
-      src->size() - ConstantPoolArray::kFirstEntryOffset);
-  return obj;
-}
-
-
-AllocationResult Heap::AllocateRawFixedArray(int length,
-                                             PretenureFlag pretenure) {
-  if (length < 0 || length > FixedArray::kMaxLength) {
-    v8::internal::Heap::FatalProcessOutOfMemory("invalid array length", true);
-  }
-  int size = FixedArray::SizeFor(length);
-  AllocationSpace space = SelectSpace(size, OLD_POINTER_SPACE, pretenure);
-
-  return AllocateRaw(size, space, OLD_POINTER_SPACE);
-}
-
-
-AllocationResult Heap::AllocateFixedArrayWithFiller(int length,
-                                                    PretenureFlag pretenure,
-                                                    Object* filler) {
-  DCHECK(length >= 0);
-  DCHECK(empty_fixed_array()->IsFixedArray());
-  if (length == 0) return empty_fixed_array();
-
-  DCHECK(!InNewSpace(filler));
-  HeapObject* result;
-  { AllocationResult allocation = AllocateRawFixedArray(length, pretenure);
-    if (!allocation.To(&result)) return allocation;
-  }
-
-  result->set_map_no_write_barrier(fixed_array_map());
-  FixedArray* array = FixedArray::cast(result);
-  array->set_length(length);
-  MemsetPointer(array->data_start(), filler, length);
-  return array;
-}
-
-
-AllocationResult Heap::AllocateFixedArray(int length, PretenureFlag pretenure) {
-  return AllocateFixedArrayWithFiller(length, pretenure, undefined_value());
-}
-
-
-AllocationResult Heap::AllocateUninitializedFixedArray(int length) {
-  if (length == 0) return empty_fixed_array();
-
-  HeapObject* obj;
-  { AllocationResult allocation = AllocateRawFixedArray(length, NOT_TENURED);
-    if (!allocation.To(&obj)) return allocation;
-  }
-
-  obj->set_map_no_write_barrier(fixed_array_map());
-  FixedArray::cast(obj)->set_length(length);
-  return obj;
-}
-
-
-AllocationResult Heap::AllocateUninitializedFixedDoubleArray(
-    int length,
-    PretenureFlag pretenure) {
-  if (length == 0) return empty_fixed_array();
-
-  HeapObject* elements;
-  AllocationResult allocation = AllocateRawFixedDoubleArray(length, pretenure);
-  if (!allocation.To(&elements)) return allocation;
-
-  elements->set_map_no_write_barrier(fixed_double_array_map());
-  FixedDoubleArray::cast(elements)->set_length(length);
-  return elements;
-}
-
-
-AllocationResult Heap::AllocateRawFixedDoubleArray(int length,
-                                                   PretenureFlag pretenure) {
-  if (length < 0 || length > FixedDoubleArray::kMaxLength) {
-    v8::internal::Heap::FatalProcessOutOfMemory("invalid array length", true);
-  }
-  int size = FixedDoubleArray::SizeFor(length);
-#ifndef V8_HOST_ARCH_64_BIT
-  size += kPointerSize;
-#endif
-  AllocationSpace space = SelectSpace(size, OLD_DATA_SPACE, pretenure);
-
-  HeapObject* object;
-  { AllocationResult allocation = AllocateRaw(size, space, OLD_DATA_SPACE);
-    if (!allocation.To(&object)) return allocation;
-  }
-
-  return EnsureDoubleAligned(this, object, size);
-}
-
-
-AllocationResult Heap::AllocateConstantPoolArray(
-      const ConstantPoolArray::NumberOfEntries& small) {
-  CHECK(small.are_in_range(0, ConstantPoolArray::kMaxSmallEntriesPerType));
-  int size = ConstantPoolArray::SizeFor(small);
-#ifndef V8_HOST_ARCH_64_BIT
-  size += kPointerSize;
-#endif
-  AllocationSpace space = SelectSpace(size, OLD_POINTER_SPACE, TENURED);
-
-  HeapObject* object;
-  { AllocationResult allocation = AllocateRaw(size, space, OLD_POINTER_SPACE);
-    if (!allocation.To(&object)) return allocation;
-  }
-  object = EnsureDoubleAligned(this, object, size);
-  object->set_map_no_write_barrier(constant_pool_array_map());
-
-  ConstantPoolArray* constant_pool = ConstantPoolArray::cast(object);
-  constant_pool->Init(small);
-  constant_pool->ClearPtrEntries(isolate());
-  return constant_pool;
-}
-
-
-AllocationResult Heap::AllocateExtendedConstantPoolArray(
-    const ConstantPoolArray::NumberOfEntries& small,
-    const ConstantPoolArray::NumberOfEntries& extended) {
-  CHECK(small.are_in_range(0, ConstantPoolArray::kMaxSmallEntriesPerType));
-  CHECK(extended.are_in_range(0, kMaxInt));
-  int size = ConstantPoolArray::SizeForExtended(small, extended);
-#ifndef V8_HOST_ARCH_64_BIT
-  size += kPointerSize;
-#endif
-  AllocationSpace space = SelectSpace(size, OLD_POINTER_SPACE, TENURED);
-
-  HeapObject* object;
-  { AllocationResult allocation = AllocateRaw(size, space, OLD_POINTER_SPACE);
-    if (!allocation.To(&object)) return allocation;
-  }
-  object = EnsureDoubleAligned(this, object, size);
-  object->set_map_no_write_barrier(constant_pool_array_map());
-
-  ConstantPoolArray* constant_pool = ConstantPoolArray::cast(object);
-  constant_pool->InitExtended(small, extended);
-  constant_pool->ClearPtrEntries(isolate());
-  return constant_pool;
-}
-
-
-AllocationResult Heap::AllocateEmptyConstantPoolArray() {
-  ConstantPoolArray::NumberOfEntries small(0, 0, 0, 0);
-  int size = ConstantPoolArray::SizeFor(small);
-  HeapObject* result;
-  { AllocationResult allocation =
-        AllocateRaw(size, OLD_DATA_SPACE, OLD_DATA_SPACE);
-    if (!allocation.To(&result)) return allocation;
-  }
-  result->set_map_no_write_barrier(constant_pool_array_map());
-  ConstantPoolArray::cast(result)->Init(small);
-  return result;
-}
-
-
-AllocationResult Heap::AllocateSymbol() {
-  // Statically ensure that it is safe to allocate symbols in paged spaces.
-  STATIC_ASSERT(Symbol::kSize <= Page::kMaxRegularHeapObjectSize);
-
-  HeapObject* result;
-  AllocationResult allocation =
-      AllocateRaw(Symbol::kSize, OLD_POINTER_SPACE, OLD_POINTER_SPACE);
-  if (!allocation.To(&result)) return allocation;
-
-  result->set_map_no_write_barrier(symbol_map());
-
-  // Generate a random hash value.
-  int hash;
-  int attempts = 0;
-  do {
-    hash = isolate()->random_number_generator()->NextInt() & Name::kHashBitMask;
-    attempts++;
-  } while (hash == 0 && attempts < 30);
-  if (hash == 0) hash = 1;  // never return 0
-
-  Symbol::cast(result)->set_hash_field(
-      Name::kIsNotArrayIndexMask | (hash << Name::kHashShift));
-  Symbol::cast(result)->set_name(undefined_value());
-  Symbol::cast(result)->set_flags(Smi::FromInt(0));
-
-  DCHECK(!Symbol::cast(result)->is_private());
-  return result;
-}
-
-
-AllocationResult Heap::AllocateStruct(InstanceType type) {
-  Map* map;
-  switch (type) {
-#define MAKE_CASE(NAME, Name, name) \
-    case NAME##_TYPE: map = name##_map(); break;
-STRUCT_LIST(MAKE_CASE)
-#undef MAKE_CASE
-    default:
-      UNREACHABLE();
-      return exception();
-  }
-  int size = map->instance_size();
-  AllocationSpace space = SelectSpace(size, OLD_POINTER_SPACE, TENURED);
-  Struct* result;
-  { AllocationResult allocation = Allocate(map, space);
-    if (!allocation.To(&result)) return allocation;
-  }
-  result->InitializeBody(size);
-  return result;
-}
-
-
-bool Heap::IsHeapIterable() {
-  // TODO(hpayer): This function is not correct. Allocation folding in old
-  // space breaks the iterability.
-  return (old_pointer_space()->swept_precisely() &&
-          old_data_space()->swept_precisely() &&
-          new_space_top_after_last_gc_ == new_space()->top());
-}
-
-
-void Heap::MakeHeapIterable() {
-  DCHECK(AllowHeapAllocation::IsAllowed());
-  if (!IsHeapIterable()) {
-    CollectAllGarbage(kMakeHeapIterableMask, "Heap::MakeHeapIterable");
-  }
-  if (mark_compact_collector()->sweeping_in_progress()) {
-    mark_compact_collector()->EnsureSweepingCompleted();
-  }
-  DCHECK(IsHeapIterable());
-}
-
-
-void Heap::AdvanceIdleIncrementalMarking(intptr_t step_size) {
-  incremental_marking()->Step(step_size,
-                              IncrementalMarking::NO_GC_VIA_STACK_GUARD);
-
-  if (incremental_marking()->IsComplete()) {
-    bool uncommit = false;
-    if (gc_count_at_last_idle_gc_ == gc_count_) {
-      // No GC since the last full GC, the mutator is probably not active.
-      isolate_->compilation_cache()->Clear();
-      uncommit = true;
-    }
-    CollectAllGarbage(kReduceMemoryFootprintMask,
-                      "idle notification: finalize incremental");
-    mark_sweeps_since_idle_round_started_++;
-    gc_count_at_last_idle_gc_ = gc_count_;
-    if (uncommit) {
-      new_space_.Shrink();
-      UncommitFromSpace();
-    }
-  }
-}
-
-
-bool Heap::IdleNotification(int hint) {
-  // If incremental marking is off, we do not perform idle notification.
-  if (!FLAG_incremental_marking) return true;
-
-  // Hints greater than this value indicate that
-  // the embedder is requesting a lot of GC work.
-  const int kMaxHint = 1000;
-  const int kMinHintForIncrementalMarking = 10;
-  // Minimal hint that allows to do full GC.
-  const int kMinHintForFullGC = 100;
-  intptr_t size_factor = Min(Max(hint, 20), kMaxHint) / 4;
-  // The size factor is in range [5..250]. The numbers here are chosen from
-  // experiments. If you changes them, make sure to test with
-  // chrome/performance_ui_tests --gtest_filter="GeneralMixMemoryTest.*
-  intptr_t step_size =
-      size_factor * IncrementalMarking::kAllocatedThreshold;
-
-  isolate()->counters()->gc_idle_time_allotted_in_ms()->AddSample(hint);
-  HistogramTimerScope idle_notification_scope(
-      isolate_->counters()->gc_idle_notification());
-
-  if (contexts_disposed_ > 0) {
-    contexts_disposed_ = 0;
-    int mark_sweep_time = Min(TimeMarkSweepWouldTakeInMs(), 1000);
-    if (hint >= mark_sweep_time && !FLAG_expose_gc &&
-        incremental_marking()->IsStopped()) {
-      HistogramTimerScope scope(isolate_->counters()->gc_context());
-      CollectAllGarbage(kReduceMemoryFootprintMask,
-                        "idle notification: contexts disposed");
-    } else {
-      AdvanceIdleIncrementalMarking(step_size);
-    }
-
-    // After context disposal there is likely a lot of garbage remaining, reset
-    // the idle notification counters in order to trigger more incremental GCs
-    // on subsequent idle notifications.
-    StartIdleRound();
-    return false;
-  }
-
-  // By doing small chunks of GC work in each IdleNotification,
-  // perform a round of incremental GCs and after that wait until
-  // the mutator creates enough garbage to justify a new round.
-  // An incremental GC progresses as follows:
-  // 1. many incremental marking steps,
-  // 2. one old space mark-sweep-compact,
-  // Use mark-sweep-compact events to count incremental GCs in a round.
-
-  if (mark_sweeps_since_idle_round_started_ >= kMaxMarkSweepsInIdleRound) {
-    if (EnoughGarbageSinceLastIdleRound()) {
-      StartIdleRound();
-    } else {
-      return true;
-    }
-  }
-
-  int remaining_mark_sweeps = kMaxMarkSweepsInIdleRound -
-                              mark_sweeps_since_idle_round_started_;
-
-  if (incremental_marking()->IsStopped()) {
-    // If there are no more than two GCs left in this idle round and we are
-    // allowed to do a full GC, then make those GCs full in order to compact
-    // the code space.
-    // TODO(ulan): Once we enable code compaction for incremental marking,
-    // we can get rid of this special case and always start incremental marking.
-    if (remaining_mark_sweeps <= 2 && hint >= kMinHintForFullGC) {
-      CollectAllGarbage(kReduceMemoryFootprintMask,
-                        "idle notification: finalize idle round");
-      mark_sweeps_since_idle_round_started_++;
-    } else if (hint > kMinHintForIncrementalMarking) {
-      incremental_marking()->Start();
-    }
-  }
-  if (!incremental_marking()->IsStopped() &&
-      hint > kMinHintForIncrementalMarking) {
-    AdvanceIdleIncrementalMarking(step_size);
-  }
-
-  if (mark_sweeps_since_idle_round_started_ >= kMaxMarkSweepsInIdleRound) {
-    FinishIdleRound();
-    return true;
-  }
-
-  // If the IdleNotifcation is called with a large hint we will wait for
-  // the sweepter threads here.
-  if (hint >= kMinHintForFullGC &&
-      mark_compact_collector()->sweeping_in_progress()) {
-    mark_compact_collector()->EnsureSweepingCompleted();
-  }
-
-  return false;
-}
-
-
-#ifdef DEBUG
-
-void Heap::Print() {
-  if (!HasBeenSetUp()) return;
-  isolate()->PrintStack(stdout);
-  AllSpaces spaces(this);
-  for (Space* space = spaces.next(); space != NULL; space = spaces.next()) {
-    space->Print();
-  }
-}
-
-
-void Heap::ReportCodeStatistics(const char* title) {
-  PrintF(">>>>>> Code Stats (%s) >>>>>>\n", title);
-  PagedSpace::ResetCodeStatistics(isolate());
-  // We do not look for code in new space, map space, or old space.  If code
-  // somehow ends up in those spaces, we would miss it here.
-  code_space_->CollectCodeStatistics();
-  lo_space_->CollectCodeStatistics();
-  PagedSpace::ReportCodeStatistics(isolate());
-}
-
-
-// This function expects that NewSpace's allocated objects histogram is
-// populated (via a call to CollectStatistics or else as a side effect of a
-// just-completed scavenge collection).
-void Heap::ReportHeapStatistics(const char* title) {
-  USE(title);
-  PrintF(">>>>>> =============== %s (%d) =============== >>>>>>\n",
-         title, gc_count_);
-  PrintF("old_generation_allocation_limit_ %" V8_PTR_PREFIX "d\n",
-         old_generation_allocation_limit_);
-
-  PrintF("\n");
-  PrintF("Number of handles : %d\n", HandleScope::NumberOfHandles(isolate_));
-  isolate_->global_handles()->PrintStats();
-  PrintF("\n");
-
-  PrintF("Heap statistics : ");
-  isolate_->memory_allocator()->ReportStatistics();
-  PrintF("To space : ");
-  new_space_.ReportStatistics();
-  PrintF("Old pointer space : ");
-  old_pointer_space_->ReportStatistics();
-  PrintF("Old data space : ");
-  old_data_space_->ReportStatistics();
-  PrintF("Code space : ");
-  code_space_->ReportStatistics();
-  PrintF("Map space : ");
-  map_space_->ReportStatistics();
-  PrintF("Cell space : ");
-  cell_space_->ReportStatistics();
-  PrintF("PropertyCell space : ");
-  property_cell_space_->ReportStatistics();
-  PrintF("Large object space : ");
-  lo_space_->ReportStatistics();
-  PrintF(">>>>>> ========================================= >>>>>>\n");
-}
-
-#endif  // DEBUG
-
-bool Heap::Contains(HeapObject* value) {
-  return Contains(value->address());
-}
-
-
-bool Heap::Contains(Address addr) {
-  if (isolate_->memory_allocator()->IsOutsideAllocatedSpace(addr)) return false;
-  return HasBeenSetUp() &&
-    (new_space_.ToSpaceContains(addr) ||
-     old_pointer_space_->Contains(addr) ||
-     old_data_space_->Contains(addr) ||
-     code_space_->Contains(addr) ||
-     map_space_->Contains(addr) ||
-     cell_space_->Contains(addr) ||
-     property_cell_space_->Contains(addr) ||
-     lo_space_->SlowContains(addr));
-}
-
-
-bool Heap::InSpace(HeapObject* value, AllocationSpace space) {
-  return InSpace(value->address(), space);
-}
-
-
-bool Heap::InSpace(Address addr, AllocationSpace space) {
-  if (isolate_->memory_allocator()->IsOutsideAllocatedSpace(addr)) return false;
-  if (!HasBeenSetUp()) return false;
-
-  switch (space) {
-    case NEW_SPACE:
-      return new_space_.ToSpaceContains(addr);
-    case OLD_POINTER_SPACE:
-      return old_pointer_space_->Contains(addr);
-    case OLD_DATA_SPACE:
-      return old_data_space_->Contains(addr);
-    case CODE_SPACE:
-      return code_space_->Contains(addr);
-    case MAP_SPACE:
-      return map_space_->Contains(addr);
-    case CELL_SPACE:
-      return cell_space_->Contains(addr);
-    case PROPERTY_CELL_SPACE:
-      return property_cell_space_->Contains(addr);
-    case LO_SPACE:
-      return lo_space_->SlowContains(addr);
-    case INVALID_SPACE:
-      break;
-  }
-  UNREACHABLE();
-  return false;
-}
-
-
-#ifdef VERIFY_HEAP
-void Heap::Verify() {
-  CHECK(HasBeenSetUp());
-  HandleScope scope(isolate());
-
-  store_buffer()->Verify();
-
-  if (mark_compact_collector()->sweeping_in_progress()) {
-    // We have to wait here for the sweeper threads to have an iterable heap.
-    mark_compact_collector()->EnsureSweepingCompleted();
-  }
-
-  VerifyPointersVisitor visitor;
-  IterateRoots(&visitor, VISIT_ONLY_STRONG);
-
-  VerifySmisVisitor smis_visitor;
-  IterateSmiRoots(&smis_visitor);
-
-  new_space_.Verify();
-
-  old_pointer_space_->Verify(&visitor);
-  map_space_->Verify(&visitor);
-
-  VerifyPointersVisitor no_dirty_regions_visitor;
-  old_data_space_->Verify(&no_dirty_regions_visitor);
-  code_space_->Verify(&no_dirty_regions_visitor);
-  cell_space_->Verify(&no_dirty_regions_visitor);
-  property_cell_space_->Verify(&no_dirty_regions_visitor);
-
-  lo_space_->Verify();
-}
-#endif
-
-
-void Heap::ZapFromSpace() {
-  NewSpacePageIterator it(new_space_.FromSpaceStart(),
-                          new_space_.FromSpaceEnd());
-  while (it.has_next()) {
-    NewSpacePage* page = it.next();
-    for (Address cursor = page->area_start(), limit = page->area_end();
-         cursor < limit;
-         cursor += kPointerSize) {
-      Memory::Address_at(cursor) = kFromSpaceZapValue;
-    }
-  }
-}
-
-
-void Heap::IterateAndMarkPointersToFromSpace(Address start,
-                                             Address end,
-                                             ObjectSlotCallback callback) {
-  Address slot_address = start;
-
-  // We are not collecting slots on new space objects during mutation
-  // thus we have to scan for pointers to evacuation candidates when we
-  // promote objects. But we should not record any slots in non-black
-  // objects. Grey object's slots would be rescanned.
-  // White object might not survive until the end of collection
-  // it would be a violation of the invariant to record it's slots.
-  bool record_slots = false;
-  if (incremental_marking()->IsCompacting()) {
-    MarkBit mark_bit = Marking::MarkBitFrom(HeapObject::FromAddress(start));
-    record_slots = Marking::IsBlack(mark_bit);
-  }
-
-  while (slot_address < end) {
-    Object** slot = reinterpret_cast<Object**>(slot_address);
-    Object* object = *slot;
-    // If the store buffer becomes overfull we mark pages as being exempt from
-    // the store buffer.  These pages are scanned to find pointers that point
-    // to the new space.  In that case we may hit newly promoted objects and
-    // fix the pointers before the promotion queue gets to them.  Thus the 'if'.
-    if (object->IsHeapObject()) {
-      if (Heap::InFromSpace(object)) {
-        callback(reinterpret_cast<HeapObject**>(slot),
-                 HeapObject::cast(object));
-        Object* new_object = *slot;
-        if (InNewSpace(new_object)) {
-          SLOW_DCHECK(Heap::InToSpace(new_object));
-          SLOW_DCHECK(new_object->IsHeapObject());
-          store_buffer_.EnterDirectlyIntoStoreBuffer(
-              reinterpret_cast<Address>(slot));
-        }
-        SLOW_DCHECK(!MarkCompactCollector::IsOnEvacuationCandidate(new_object));
-      } else if (record_slots &&
-                 MarkCompactCollector::IsOnEvacuationCandidate(object)) {
-        mark_compact_collector()->RecordSlot(slot, slot, object);
-      }
-    }
-    slot_address += kPointerSize;
-  }
-}
-
-
-#ifdef DEBUG
-typedef bool (*CheckStoreBufferFilter)(Object** addr);
-
-
-bool IsAMapPointerAddress(Object** addr) {
-  uintptr_t a = reinterpret_cast<uintptr_t>(addr);
-  int mod = a % Map::kSize;
-  return mod >= Map::kPointerFieldsBeginOffset &&
-         mod < Map::kPointerFieldsEndOffset;
-}
-
-
-bool EverythingsAPointer(Object** addr) {
-  return true;
-}
-
-
-static void CheckStoreBuffer(Heap* heap,
-                             Object** current,
-                             Object** limit,
-                             Object**** store_buffer_position,
-                             Object*** store_buffer_top,
-                             CheckStoreBufferFilter filter,
-                             Address special_garbage_start,
-                             Address special_garbage_end) {
-  Map* free_space_map = heap->free_space_map();
-  for ( ; current < limit; current++) {
-    Object* o = *current;
-    Address current_address = reinterpret_cast<Address>(current);
-    // Skip free space.
-    if (o == free_space_map) {
-      Address current_address = reinterpret_cast<Address>(current);
-      FreeSpace* free_space =
-          FreeSpace::cast(HeapObject::FromAddress(current_address));
-      int skip = free_space->Size();
-      DCHECK(current_address + skip <= reinterpret_cast<Address>(limit));
-      DCHECK(skip > 0);
-      current_address += skip - kPointerSize;
-      current = reinterpret_cast<Object**>(current_address);
-      continue;
-    }
-    // Skip the current linear allocation space between top and limit which is
-    // unmarked with the free space map, but can contain junk.
-    if (current_address == special_garbage_start &&
-        special_garbage_end != special_garbage_start) {
-      current_address = special_garbage_end - kPointerSize;
-      current = reinterpret_cast<Object**>(current_address);
-      continue;
-    }
-    if (!(*filter)(current)) continue;
-    DCHECK(current_address < special_garbage_start ||
-           current_address >= special_garbage_end);
-    DCHECK(reinterpret_cast<uintptr_t>(o) != kFreeListZapValue);
-    // We have to check that the pointer does not point into new space
-    // without trying to cast it to a heap object since the hash field of
-    // a string can contain values like 1 and 3 which are tagged null
-    // pointers.
-    if (!heap->InNewSpace(o)) continue;
-    while (**store_buffer_position < current &&
-           *store_buffer_position < store_buffer_top) {
-      (*store_buffer_position)++;
-    }
-    if (**store_buffer_position != current ||
-        *store_buffer_position == store_buffer_top) {
-      Object** obj_start = current;
-      while (!(*obj_start)->IsMap()) obj_start--;
-      UNREACHABLE();
-    }
-  }
-}
-
-
-// Check that the store buffer contains all intergenerational pointers by
-// scanning a page and ensuring that all pointers to young space are in the
-// store buffer.
-void Heap::OldPointerSpaceCheckStoreBuffer() {
-  OldSpace* space = old_pointer_space();
-  PageIterator pages(space);
-
-  store_buffer()->SortUniq();
-
-  while (pages.has_next()) {
-    Page* page = pages.next();
-    Object** current = reinterpret_cast<Object**>(page->area_start());
-
-    Address end = page->area_end();
-
-    Object*** store_buffer_position = store_buffer()->Start();
-    Object*** store_buffer_top = store_buffer()->Top();
-
-    Object** limit = reinterpret_cast<Object**>(end);
-    CheckStoreBuffer(this,
-                     current,
-                     limit,
-                     &store_buffer_position,
-                     store_buffer_top,
-                     &EverythingsAPointer,
-                     space->top(),
-                     space->limit());
-  }
-}
-
-
-void Heap::MapSpaceCheckStoreBuffer() {
-  MapSpace* space = map_space();
-  PageIterator pages(space);
-
-  store_buffer()->SortUniq();
-
-  while (pages.has_next()) {
-    Page* page = pages.next();
-    Object** current = reinterpret_cast<Object**>(page->area_start());
-
-    Address end = page->area_end();
-
-    Object*** store_buffer_position = store_buffer()->Start();
-    Object*** store_buffer_top = store_buffer()->Top();
-
-    Object** limit = reinterpret_cast<Object**>(end);
-    CheckStoreBuffer(this,
-                     current,
-                     limit,
-                     &store_buffer_position,
-                     store_buffer_top,
-                     &IsAMapPointerAddress,
-                     space->top(),
-                     space->limit());
-  }
-}
-
-
-void Heap::LargeObjectSpaceCheckStoreBuffer() {
-  LargeObjectIterator it(lo_space());
-  for (HeapObject* object = it.Next(); object != NULL; object = it.Next()) {
-    // We only have code, sequential strings, or fixed arrays in large
-    // object space, and only fixed arrays can possibly contain pointers to
-    // the young generation.
-    if (object->IsFixedArray()) {
-      Object*** store_buffer_position = store_buffer()->Start();
-      Object*** store_buffer_top = store_buffer()->Top();
-      Object** current = reinterpret_cast<Object**>(object->address());
-      Object** limit =
-          reinterpret_cast<Object**>(object->address() + object->Size());
-      CheckStoreBuffer(this,
-                       current,
-                       limit,
-                       &store_buffer_position,
-                       store_buffer_top,
-                       &EverythingsAPointer,
-                       NULL,
-                       NULL);
-    }
-  }
-}
-#endif
-
-
-void Heap::IterateRoots(ObjectVisitor* v, VisitMode mode) {
-  IterateStrongRoots(v, mode);
-  IterateWeakRoots(v, mode);
-}
-
-
-void Heap::IterateWeakRoots(ObjectVisitor* v, VisitMode mode) {
-  v->VisitPointer(reinterpret_cast<Object**>(&roots_[kStringTableRootIndex]));
-  v->Synchronize(VisitorSynchronization::kStringTable);
-  if (mode != VISIT_ALL_IN_SCAVENGE &&
-      mode != VISIT_ALL_IN_SWEEP_NEWSPACE) {
-    // Scavenge collections have special processing for this.
-    external_string_table_.Iterate(v);
-  }
-  v->Synchronize(VisitorSynchronization::kExternalStringsTable);
-}
-
-
-void Heap::IterateSmiRoots(ObjectVisitor* v) {
-  // Acquire execution access since we are going to read stack limit values.
-  ExecutionAccess access(isolate());
-  v->VisitPointers(&roots_[kSmiRootsStart], &roots_[kRootListLength]);
-  v->Synchronize(VisitorSynchronization::kSmiRootList);
-}
-
-
-void Heap::IterateStrongRoots(ObjectVisitor* v, VisitMode mode) {
-  v->VisitPointers(&roots_[0], &roots_[kStrongRootListLength]);
-  v->Synchronize(VisitorSynchronization::kStrongRootList);
-
-  v->VisitPointer(BitCast<Object**>(&hidden_string_));
-  v->Synchronize(VisitorSynchronization::kInternalizedString);
-
-  isolate_->bootstrapper()->Iterate(v);
-  v->Synchronize(VisitorSynchronization::kBootstrapper);
-  isolate_->Iterate(v);
-  v->Synchronize(VisitorSynchronization::kTop);
-  Relocatable::Iterate(isolate_, v);
-  v->Synchronize(VisitorSynchronization::kRelocatable);
-
-  if (isolate_->deoptimizer_data() != NULL) {
-    isolate_->deoptimizer_data()->Iterate(v);
-  }
-  v->Synchronize(VisitorSynchronization::kDebug);
-  isolate_->compilation_cache()->Iterate(v);
-  v->Synchronize(VisitorSynchronization::kCompilationCache);
-
-  // Iterate over local handles in handle scopes.
-  isolate_->handle_scope_implementer()->Iterate(v);
-  isolate_->IterateDeferredHandles(v);
-  v->Synchronize(VisitorSynchronization::kHandleScope);
-
-  // Iterate over the builtin code objects and code stubs in the
-  // heap. Note that it is not necessary to iterate over code objects
-  // on scavenge collections.
-  if (mode != VISIT_ALL_IN_SCAVENGE) {
-    isolate_->builtins()->IterateBuiltins(v);
-  }
-  v->Synchronize(VisitorSynchronization::kBuiltins);
-
-  // Iterate over global handles.
-  switch (mode) {
-    case VISIT_ONLY_STRONG:
-      isolate_->global_handles()->IterateStrongRoots(v);
-      break;
-    case VISIT_ALL_IN_SCAVENGE:
-      isolate_->global_handles()->IterateNewSpaceStrongAndDependentRoots(v);
-      break;
-    case VISIT_ALL_IN_SWEEP_NEWSPACE:
-    case VISIT_ALL:
-      isolate_->global_handles()->IterateAllRoots(v);
-      break;
-  }
-  v->Synchronize(VisitorSynchronization::kGlobalHandles);
-
-  // Iterate over eternal handles.
-  if (mode == VISIT_ALL_IN_SCAVENGE) {
-    isolate_->eternal_handles()->IterateNewSpaceRoots(v);
-  } else {
-    isolate_->eternal_handles()->IterateAllRoots(v);
-  }
-  v->Synchronize(VisitorSynchronization::kEternalHandles);
-
-  // Iterate over pointers being held by inactive threads.
-  isolate_->thread_manager()->Iterate(v);
-  v->Synchronize(VisitorSynchronization::kThreadManager);
-
-  // Iterate over the pointers the Serialization/Deserialization code is
-  // holding.
-  // During garbage collection this keeps the partial snapshot cache alive.
-  // During deserialization of the startup snapshot this creates the partial
-  // snapshot cache and deserializes the objects it refers to.  During
-  // serialization this does nothing, since the partial snapshot cache is
-  // empty.  However the next thing we do is create the partial snapshot,
-  // filling up the partial snapshot cache with objects it needs as we go.
-  SerializerDeserializer::Iterate(isolate_, v);
-  // We don't do a v->Synchronize call here, because in debug mode that will
-  // output a flag to the snapshot.  However at this point the serializer and
-  // deserializer are deliberately a little unsynchronized (see above) so the
-  // checking of the sync flag in the snapshot would fail.
-}
-
-
-// TODO(1236194): Since the heap size is configurable on the command line
-// and through the API, we should gracefully handle the case that the heap
-// size is not big enough to fit all the initial objects.
-bool Heap::ConfigureHeap(int max_semi_space_size,
-                         int max_old_space_size,
-                         int max_executable_size,
-                         size_t code_range_size) {
-  if (HasBeenSetUp()) return false;
-
-  // Overwrite default configuration.
-  if (max_semi_space_size > 0) {
-    max_semi_space_size_ = max_semi_space_size * MB;
-  }
-  if (max_old_space_size > 0) {
-    max_old_generation_size_ = max_old_space_size * MB;
-  }
-  if (max_executable_size > 0) {
-    max_executable_size_ = max_executable_size * MB;
-  }
-
-  // If max space size flags are specified overwrite the configuration.
-  if (FLAG_max_semi_space_size > 0) {
-    max_semi_space_size_ = FLAG_max_semi_space_size * MB;
-  }
-  if (FLAG_max_old_space_size > 0) {
-    max_old_generation_size_ = FLAG_max_old_space_size * MB;
-  }
-  if (FLAG_max_executable_size > 0) {
-    max_executable_size_ = FLAG_max_executable_size * MB;
-  }
-
-  if (FLAG_stress_compaction) {
-    // This will cause more frequent GCs when stressing.
-    max_semi_space_size_ = Page::kPageSize;
-  }
-
-  if (Snapshot::HaveASnapshotToStartFrom()) {
-    // If we are using a snapshot we always reserve the default amount
-    // of memory for each semispace because code in the snapshot has
-    // write-barrier code that relies on the size and alignment of new
-    // space.  We therefore cannot use a larger max semispace size
-    // than the default reserved semispace size.
-    if (max_semi_space_size_ > reserved_semispace_size_) {
-      max_semi_space_size_ = reserved_semispace_size_;
-      if (FLAG_trace_gc) {
-        PrintPID("Max semi-space size cannot be more than %d kbytes\n",
-                 reserved_semispace_size_ >> 10);
-      }
-    }
-  } else {
-    // If we are not using snapshots we reserve space for the actual
-    // max semispace size.
-    reserved_semispace_size_ = max_semi_space_size_;
-  }
-
-  // The max executable size must be less than or equal to the max old
-  // generation size.
-  if (max_executable_size_ > max_old_generation_size_) {
-    max_executable_size_ = max_old_generation_size_;
-  }
-
-  // The new space size must be a power of two to support single-bit testing
-  // for containment.
-  max_semi_space_size_ = RoundUpToPowerOf2(max_semi_space_size_);
-  reserved_semispace_size_ = RoundUpToPowerOf2(reserved_semispace_size_);
-
-  if (FLAG_min_semi_space_size > 0) {
-    int initial_semispace_size = FLAG_min_semi_space_size * MB;
-    if (initial_semispace_size > max_semi_space_size_) {
-      initial_semispace_size_ = max_semi_space_size_;
-      if (FLAG_trace_gc) {
-        PrintPID("Min semi-space size cannot be more than the maximum"
-                 "semi-space size of %d MB\n", max_semi_space_size_);
-      }
-    } else {
-      initial_semispace_size_ = initial_semispace_size;
-    }
-  }
-
-  initial_semispace_size_ = Min(initial_semispace_size_, max_semi_space_size_);
-
-  // The old generation is paged and needs at least one page for each space.
-  int paged_space_count = LAST_PAGED_SPACE - FIRST_PAGED_SPACE + 1;
-  max_old_generation_size_ =
-      Max(static_cast<intptr_t>(paged_space_count * Page::kPageSize),
-          max_old_generation_size_);
-
-  // We rely on being able to allocate new arrays in paged spaces.
-  DCHECK(Page::kMaxRegularHeapObjectSize >=
-         (JSArray::kSize +
-          FixedArray::SizeFor(JSObject::kInitialMaxFastElementArray) +
-          AllocationMemento::kSize));
-
-  code_range_size_ = code_range_size * MB;
-
-  configured_ = true;
-  return true;
-}
-
-
-bool Heap::ConfigureHeapDefault() {
-  return ConfigureHeap(0, 0, 0, 0);
-}
-
-
-void Heap::RecordStats(HeapStats* stats, bool take_snapshot) {
-  *stats->start_marker = HeapStats::kStartMarker;
-  *stats->end_marker = HeapStats::kEndMarker;
-  *stats->new_space_size = new_space_.SizeAsInt();
-  *stats->new_space_capacity = static_cast<int>(new_space_.Capacity());
-  *stats->old_pointer_space_size = old_pointer_space_->SizeOfObjects();
-  *stats->old_pointer_space_capacity = old_pointer_space_->Capacity();
-  *stats->old_data_space_size = old_data_space_->SizeOfObjects();
-  *stats->old_data_space_capacity = old_data_space_->Capacity();
-  *stats->code_space_size = code_space_->SizeOfObjects();
-  *stats->code_space_capacity = code_space_->Capacity();
-  *stats->map_space_size = map_space_->SizeOfObjects();
-  *stats->map_space_capacity = map_space_->Capacity();
-  *stats->cell_space_size = cell_space_->SizeOfObjects();
-  *stats->cell_space_capacity = cell_space_->Capacity();
-  *stats->property_cell_space_size = property_cell_space_->SizeOfObjects();
-  *stats->property_cell_space_capacity = property_cell_space_->Capacity();
-  *stats->lo_space_size = lo_space_->Size();
-  isolate_->global_handles()->RecordStats(stats);
-  *stats->memory_allocator_size = isolate()->memory_allocator()->Size();
-  *stats->memory_allocator_capacity =
-      isolate()->memory_allocator()->Size() +
-      isolate()->memory_allocator()->Available();
-  *stats->os_error = base::OS::GetLastError();
-      isolate()->memory_allocator()->Available();
-  if (take_snapshot) {
-    HeapIterator iterator(this);
-    for (HeapObject* obj = iterator.next();
-         obj != NULL;
-         obj = iterator.next()) {
-      InstanceType type = obj->map()->instance_type();
-      DCHECK(0 <= type && type <= LAST_TYPE);
-      stats->objects_per_type[type]++;
-      stats->size_per_type[type] += obj->Size();
-    }
-  }
-}
-
-
-intptr_t Heap::PromotedSpaceSizeOfObjects() {
-  return old_pointer_space_->SizeOfObjects()
-      + old_data_space_->SizeOfObjects()
-      + code_space_->SizeOfObjects()
-      + map_space_->SizeOfObjects()
-      + cell_space_->SizeOfObjects()
-      + property_cell_space_->SizeOfObjects()
-      + lo_space_->SizeOfObjects();
-}
-
-
-int64_t Heap::PromotedExternalMemorySize() {
-  if (amount_of_external_allocated_memory_
-      <= amount_of_external_allocated_memory_at_last_global_gc_) return 0;
-  return amount_of_external_allocated_memory_
-      - amount_of_external_allocated_memory_at_last_global_gc_;
-}
-
-
-intptr_t Heap::OldGenerationAllocationLimit(intptr_t old_gen_size,
-                                            int freed_global_handles) {
-  const int kMaxHandles = 1000;
-  const int kMinHandles = 100;
-  double min_factor = 1.1;
-  double max_factor = 4;
-  // We set the old generation growing factor to 2 to grow the heap slower on
-  // memory-constrained devices.
-  if (max_old_generation_size_ <= kMaxOldSpaceSizeMediumMemoryDevice) {
-    max_factor = 2;
-  }
-  // If there are many freed global handles, then the next full GC will
-  // likely collect a lot of garbage. Choose the heap growing factor
-  // depending on freed global handles.
-  // TODO(ulan, hpayer): Take into account mutator utilization.
-  double factor;
-  if (freed_global_handles <= kMinHandles) {
-    factor = max_factor;
-  } else if (freed_global_handles >= kMaxHandles) {
-    factor = min_factor;
-  } else {
-    // Compute factor using linear interpolation between points
-    // (kMinHandles, max_factor) and (kMaxHandles, min_factor).
-    factor = max_factor -
-             (freed_global_handles - kMinHandles) * (max_factor - min_factor) /
-             (kMaxHandles - kMinHandles);
-  }
-
-  if (FLAG_stress_compaction ||
-      mark_compact_collector()->reduce_memory_footprint_) {
-    factor = min_factor;
-  }
-
-  intptr_t limit = static_cast<intptr_t>(old_gen_size * factor);
-  limit = Max(limit, kMinimumOldGenerationAllocationLimit);
-  limit += new_space_.Capacity();
-  intptr_t halfway_to_the_max = (old_gen_size + max_old_generation_size_) / 2;
-  return Min(limit, halfway_to_the_max);
-}
-
-
-void Heap::EnableInlineAllocation() {
-  if (!inline_allocation_disabled_) return;
-  inline_allocation_disabled_ = false;
-
-  // Update inline allocation limit for new space.
-  new_space()->UpdateInlineAllocationLimit(0);
-}
-
-
-void Heap::DisableInlineAllocation() {
-  if (inline_allocation_disabled_) return;
-  inline_allocation_disabled_ = true;
-
-  // Update inline allocation limit for new space.
-  new_space()->UpdateInlineAllocationLimit(0);
-
-  // Update inline allocation limit for old spaces.
-  PagedSpaces spaces(this);
-  for (PagedSpace* space = spaces.next();
-       space != NULL;
-       space = spaces.next()) {
-    space->EmptyAllocationInfo();
-  }
-}
-
-
-V8_DECLARE_ONCE(initialize_gc_once);
-
-static void InitializeGCOnce() {
-  InitializeScavengingVisitorsTables();
-  NewSpaceScavenger::Initialize();
-  MarkCompactCollector::Initialize();
-}
-
-
-bool Heap::SetUp() {
-#ifdef DEBUG
-  allocation_timeout_ = FLAG_gc_interval;
-#endif
-
-  // Initialize heap spaces and initial maps and objects. Whenever something
-  // goes wrong, just return false. The caller should check the results and
-  // call Heap::TearDown() to release allocated memory.
-  //
-  // If the heap is not yet configured (e.g. through the API), configure it.
-  // Configuration is based on the flags new-space-size (really the semispace
-  // size) and old-space-size if set or the initial values of semispace_size_
-  // and old_generation_size_ otherwise.
-  if (!configured_) {
-    if (!ConfigureHeapDefault()) return false;
-  }
-
-  base::CallOnce(&initialize_gc_once, &InitializeGCOnce);
-
-  MarkMapPointersAsEncoded(false);
-
-  // Set up memory allocator.
-  if (!isolate_->memory_allocator()->SetUp(MaxReserved(), MaxExecutableSize()))
-      return false;
-
-  // Set up new space.
-  if (!new_space_.SetUp(reserved_semispace_size_, max_semi_space_size_)) {
-    return false;
-  }
-  new_space_top_after_last_gc_ = new_space()->top();
-
-  // Initialize old pointer space.
-  old_pointer_space_ =
-      new OldSpace(this,
-                   max_old_generation_size_,
-                   OLD_POINTER_SPACE,
-                   NOT_EXECUTABLE);
-  if (old_pointer_space_ == NULL) return false;
-  if (!old_pointer_space_->SetUp()) return false;
-
-  // Initialize old data space.
-  old_data_space_ =
-      new OldSpace(this,
-                   max_old_generation_size_,
-                   OLD_DATA_SPACE,
-                   NOT_EXECUTABLE);
-  if (old_data_space_ == NULL) return false;
-  if (!old_data_space_->SetUp()) return false;
-
-  if (!isolate_->code_range()->SetUp(code_range_size_)) return false;
-
-  // Initialize the code space, set its maximum capacity to the old
-  // generation size. It needs executable memory.
-  code_space_ =
-      new OldSpace(this, max_old_generation_size_, CODE_SPACE, EXECUTABLE);
-  if (code_space_ == NULL) return false;
-  if (!code_space_->SetUp()) return false;
-
-  // Initialize map space.
-  map_space_ = new MapSpace(this, max_old_generation_size_, MAP_SPACE);
-  if (map_space_ == NULL) return false;
-  if (!map_space_->SetUp()) return false;
-
-  // Initialize simple cell space.
-  cell_space_ = new CellSpace(this, max_old_generation_size_, CELL_SPACE);
-  if (cell_space_ == NULL) return false;
-  if (!cell_space_->SetUp()) return false;
-
-  // Initialize global property cell space.
-  property_cell_space_ = new PropertyCellSpace(this, max_old_generation_size_,
-                                               PROPERTY_CELL_SPACE);
-  if (property_cell_space_ == NULL) return false;
-  if (!property_cell_space_->SetUp()) return false;
-
-  // The large object code space may contain code or data.  We set the memory
-  // to be non-executable here for safety, but this means we need to enable it
-  // explicitly when allocating large code objects.
-  lo_space_ = new LargeObjectSpace(this, max_old_generation_size_, LO_SPACE);
-  if (lo_space_ == NULL) return false;
-  if (!lo_space_->SetUp()) return false;
-
-  // Set up the seed that is used to randomize the string hash function.
-  DCHECK(hash_seed() == 0);
-  if (FLAG_randomize_hashes) {
-    if (FLAG_hash_seed == 0) {
-      int rnd = isolate()->random_number_generator()->NextInt();
-      set_hash_seed(Smi::FromInt(rnd & Name::kHashBitMask));
-    } else {
-      set_hash_seed(Smi::FromInt(FLAG_hash_seed));
-    }
-  }
-
-  LOG(isolate_, IntPtrTEvent("heap-capacity", Capacity()));
-  LOG(isolate_, IntPtrTEvent("heap-available", Available()));
-
-  store_buffer()->SetUp();
-
-  mark_compact_collector()->SetUp();
-
-  return true;
-}
-
-
-bool Heap::CreateHeapObjects() {
-  // Create initial maps.
-  if (!CreateInitialMaps()) return false;
-  CreateApiObjects();
-
-  // Create initial objects
-  CreateInitialObjects();
-  CHECK_EQ(0, gc_count_);
-
-  set_native_contexts_list(undefined_value());
-  set_array_buffers_list(undefined_value());
-  set_allocation_sites_list(undefined_value());
-  weak_object_to_code_table_ = undefined_value();
-  return true;
-}
-
-
-void Heap::SetStackLimits() {
-  DCHECK(isolate_ != NULL);
-  DCHECK(isolate_ == isolate());
-  // On 64 bit machines, pointers are generally out of range of Smis.  We write
-  // something that looks like an out of range Smi to the GC.
-
-  // Set up the special root array entries containing the stack limits.
-  // These are actually addresses, but the tag makes the GC ignore it.
-  roots_[kStackLimitRootIndex] =
-      reinterpret_cast<Object*>(
-          (isolate_->stack_guard()->jslimit() & ~kSmiTagMask) | kSmiTag);
-  roots_[kRealStackLimitRootIndex] =
-      reinterpret_cast<Object*>(
-          (isolate_->stack_guard()->real_jslimit() & ~kSmiTagMask) | kSmiTag);
-}
-
-
-void Heap::TearDown() {
-#ifdef VERIFY_HEAP
-  if (FLAG_verify_heap) {
-    Verify();
-  }
-#endif
-
-  UpdateMaximumCommitted();
-
-  if (FLAG_print_cumulative_gc_stat) {
-    PrintF("\n");
-    PrintF("gc_count=%d ", gc_count_);
-    PrintF("mark_sweep_count=%d ", ms_count_);
-    PrintF("max_gc_pause=%.1f ", get_max_gc_pause());
-    PrintF("total_gc_time=%.1f ", total_gc_time_ms_);
-    PrintF("min_in_mutator=%.1f ", get_min_in_mutator());
-    PrintF("max_alive_after_gc=%" V8_PTR_PREFIX "d ",
-           get_max_alive_after_gc());
-    PrintF("total_marking_time=%.1f ", tracer_.cumulative_sweeping_duration());
-    PrintF("total_sweeping_time=%.1f ", tracer_.cumulative_sweeping_duration());
-    PrintF("\n\n");
-  }
-
-  if (FLAG_print_max_heap_committed) {
-    PrintF("\n");
-    PrintF("maximum_committed_by_heap=%" V8_PTR_PREFIX "d ",
-      MaximumCommittedMemory());
-    PrintF("maximum_committed_by_new_space=%" V8_PTR_PREFIX "d ",
-      new_space_.MaximumCommittedMemory());
-    PrintF("maximum_committed_by_old_pointer_space=%" V8_PTR_PREFIX "d ",
-      old_data_space_->MaximumCommittedMemory());
-    PrintF("maximum_committed_by_old_data_space=%" V8_PTR_PREFIX "d ",
-      old_pointer_space_->MaximumCommittedMemory());
-    PrintF("maximum_committed_by_old_data_space=%" V8_PTR_PREFIX "d ",
-      old_pointer_space_->MaximumCommittedMemory());
-    PrintF("maximum_committed_by_code_space=%" V8_PTR_PREFIX "d ",
-      code_space_->MaximumCommittedMemory());
-    PrintF("maximum_committed_by_map_space=%" V8_PTR_PREFIX "d ",
-      map_space_->MaximumCommittedMemory());
-    PrintF("maximum_committed_by_cell_space=%" V8_PTR_PREFIX "d ",
-      cell_space_->MaximumCommittedMemory());
-    PrintF("maximum_committed_by_property_space=%" V8_PTR_PREFIX "d ",
-      property_cell_space_->MaximumCommittedMemory());
-    PrintF("maximum_committed_by_lo_space=%" V8_PTR_PREFIX "d ",
-      lo_space_->MaximumCommittedMemory());
-    PrintF("\n\n");
-  }
-
-  if (FLAG_verify_predictable) {
-    PrintAlloctionsHash();
-  }
-
-  TearDownArrayBuffers();
-
-  isolate_->global_handles()->TearDown();
-
-  external_string_table_.TearDown();
-
-  mark_compact_collector()->TearDown();
-
-  new_space_.TearDown();
-
-  if (old_pointer_space_ != NULL) {
-    old_pointer_space_->TearDown();
-    delete old_pointer_space_;
-    old_pointer_space_ = NULL;
-  }
-
-  if (old_data_space_ != NULL) {
-    old_data_space_->TearDown();
-    delete old_data_space_;
-    old_data_space_ = NULL;
-  }
-
-  if (code_space_ != NULL) {
-    code_space_->TearDown();
-    delete code_space_;
-    code_space_ = NULL;
-  }
-
-  if (map_space_ != NULL) {
-    map_space_->TearDown();
-    delete map_space_;
-    map_space_ = NULL;
-  }
-
-  if (cell_space_ != NULL) {
-    cell_space_->TearDown();
-    delete cell_space_;
-    cell_space_ = NULL;
-  }
-
-  if (property_cell_space_ != NULL) {
-    property_cell_space_->TearDown();
-    delete property_cell_space_;
-    property_cell_space_ = NULL;
-  }
-
-  if (lo_space_ != NULL) {
-    lo_space_->TearDown();
-    delete lo_space_;
-    lo_space_ = NULL;
-  }
-
-  store_buffer()->TearDown();
-  incremental_marking()->TearDown();
-
-  isolate_->memory_allocator()->TearDown();
-}
-
-
-void Heap::AddGCPrologueCallback(v8::Isolate::GCPrologueCallback callback,
-                                 GCType gc_type,
-                                 bool pass_isolate) {
-  DCHECK(callback != NULL);
-  GCPrologueCallbackPair pair(callback, gc_type, pass_isolate);
-  DCHECK(!gc_prologue_callbacks_.Contains(pair));
-  return gc_prologue_callbacks_.Add(pair);
-}
-
-
-void Heap::RemoveGCPrologueCallback(v8::Isolate::GCPrologueCallback callback) {
-  DCHECK(callback != NULL);
-  for (int i = 0; i < gc_prologue_callbacks_.length(); ++i) {
-    if (gc_prologue_callbacks_[i].callback == callback) {
-      gc_prologue_callbacks_.Remove(i);
-      return;
-    }
-  }
-  UNREACHABLE();
-}
-
-
-void Heap::AddGCEpilogueCallback(v8::Isolate::GCEpilogueCallback callback,
-                                 GCType gc_type,
-                                 bool pass_isolate) {
-  DCHECK(callback != NULL);
-  GCEpilogueCallbackPair pair(callback, gc_type, pass_isolate);
-  DCHECK(!gc_epilogue_callbacks_.Contains(pair));
-  return gc_epilogue_callbacks_.Add(pair);
-}
-
-
-void Heap::RemoveGCEpilogueCallback(v8::Isolate::GCEpilogueCallback callback) {
-  DCHECK(callback != NULL);
-  for (int i = 0; i < gc_epilogue_callbacks_.length(); ++i) {
-    if (gc_epilogue_callbacks_[i].callback == callback) {
-      gc_epilogue_callbacks_.Remove(i);
-      return;
-    }
-  }
-  UNREACHABLE();
-}
-
-
-// TODO(ishell): Find a better place for this.
-void Heap::AddWeakObjectToCodeDependency(Handle<Object> obj,
-                                         Handle<DependentCode> dep) {
-  DCHECK(!InNewSpace(*obj));
-  DCHECK(!InNewSpace(*dep));
-  // This handle scope keeps the table handle local to this function, which
-  // allows us to safely skip write barriers in table update operations.
-  HandleScope scope(isolate());
-  Handle<WeakHashTable> table(WeakHashTable::cast(weak_object_to_code_table_),
-                              isolate());
-  table = WeakHashTable::Put(table, obj, dep);
-
-  if (ShouldZapGarbage() && weak_object_to_code_table_ != *table) {
-    WeakHashTable::cast(weak_object_to_code_table_)->Zap(the_hole_value());
-  }
-  set_weak_object_to_code_table(*table);
-  DCHECK_EQ(*dep, table->Lookup(obj));
-}
-
-
-DependentCode* Heap::LookupWeakObjectToCodeDependency(Handle<Object> obj) {
-  Object* dep = WeakHashTable::cast(weak_object_to_code_table_)->Lookup(obj);
-  if (dep->IsDependentCode()) return DependentCode::cast(dep);
-  return DependentCode::cast(empty_fixed_array());
-}
-
-
-void Heap::EnsureWeakObjectToCodeTable() {
-  if (!weak_object_to_code_table()->IsHashTable()) {
-    set_weak_object_to_code_table(*WeakHashTable::New(
-        isolate(), 16, USE_DEFAULT_MINIMUM_CAPACITY, TENURED));
-  }
-}
-
-
-void Heap::FatalProcessOutOfMemory(const char* location, bool take_snapshot) {
-  v8::internal::V8::FatalProcessOutOfMemory(location, take_snapshot);
-}
-
-#ifdef DEBUG
-
-class PrintHandleVisitor: public ObjectVisitor {
- public:
-  void VisitPointers(Object** start, Object** end) {
-    for (Object** p = start; p < end; p++)
-      PrintF("  handle %p to %p\n",
-             reinterpret_cast<void*>(p),
-             reinterpret_cast<void*>(*p));
-  }
-};
-
-
-void Heap::PrintHandles() {
-  PrintF("Handles:\n");
-  PrintHandleVisitor v;
-  isolate_->handle_scope_implementer()->Iterate(&v);
-}
-
-#endif
-
-
-Space* AllSpaces::next() {
-  switch (counter_++) {
-    case NEW_SPACE:
-      return heap_->new_space();
-    case OLD_POINTER_SPACE:
-      return heap_->old_pointer_space();
-    case OLD_DATA_SPACE:
-      return heap_->old_data_space();
-    case CODE_SPACE:
-      return heap_->code_space();
-    case MAP_SPACE:
-      return heap_->map_space();
-    case CELL_SPACE:
-      return heap_->cell_space();
-    case PROPERTY_CELL_SPACE:
-      return heap_->property_cell_space();
-    case LO_SPACE:
-      return heap_->lo_space();
-    default:
-      return NULL;
-  }
-}
-
-
-PagedSpace* PagedSpaces::next() {
-  switch (counter_++) {
-    case OLD_POINTER_SPACE:
-      return heap_->old_pointer_space();
-    case OLD_DATA_SPACE:
-      return heap_->old_data_space();
-    case CODE_SPACE:
-      return heap_->code_space();
-    case MAP_SPACE:
-      return heap_->map_space();
-    case CELL_SPACE:
-      return heap_->cell_space();
-    case PROPERTY_CELL_SPACE:
-      return heap_->property_cell_space();
-    default:
-      return NULL;
-  }
-}
-
-
-
-OldSpace* OldSpaces::next() {
-  switch (counter_++) {
-    case OLD_POINTER_SPACE:
-      return heap_->old_pointer_space();
-    case OLD_DATA_SPACE:
-      return heap_->old_data_space();
-    case CODE_SPACE:
-      return heap_->code_space();
-    default:
-      return NULL;
-  }
-}
-
-
-SpaceIterator::SpaceIterator(Heap* heap)
-    : heap_(heap),
-      current_space_(FIRST_SPACE),
-      iterator_(NULL),
-      size_func_(NULL) {
-}
-
-
-SpaceIterator::SpaceIterator(Heap* heap, HeapObjectCallback size_func)
-    : heap_(heap),
-      current_space_(FIRST_SPACE),
-      iterator_(NULL),
-      size_func_(size_func) {
-}
-
-
-SpaceIterator::~SpaceIterator() {
-  // Delete active iterator if any.
-  delete iterator_;
-}
-
-
-bool SpaceIterator::has_next() {
-  // Iterate until no more spaces.
-  return current_space_ != LAST_SPACE;
-}
-
-
-ObjectIterator* SpaceIterator::next() {
-  if (iterator_ != NULL) {
-    delete iterator_;
-    iterator_ = NULL;
-    // Move to the next space
-    current_space_++;
-    if (current_space_ > LAST_SPACE) {
-      return NULL;
-    }
-  }
-
-  // Return iterator for the new current space.
-  return CreateIterator();
-}
-
-
-// Create an iterator for the space to iterate.
-ObjectIterator* SpaceIterator::CreateIterator() {
-  DCHECK(iterator_ == NULL);
-
-  switch (current_space_) {
-    case NEW_SPACE:
-      iterator_ = new SemiSpaceIterator(heap_->new_space(), size_func_);
-      break;
-    case OLD_POINTER_SPACE:
-      iterator_ =
-          new HeapObjectIterator(heap_->old_pointer_space(), size_func_);
-      break;
-    case OLD_DATA_SPACE:
-      iterator_ = new HeapObjectIterator(heap_->old_data_space(), size_func_);
-      break;
-    case CODE_SPACE:
-      iterator_ = new HeapObjectIterator(heap_->code_space(), size_func_);
-      break;
-    case MAP_SPACE:
-      iterator_ = new HeapObjectIterator(heap_->map_space(), size_func_);
-      break;
-    case CELL_SPACE:
-      iterator_ = new HeapObjectIterator(heap_->cell_space(), size_func_);
-      break;
-    case PROPERTY_CELL_SPACE:
-      iterator_ = new HeapObjectIterator(heap_->property_cell_space(),
-                                         size_func_);
-      break;
-    case LO_SPACE:
-      iterator_ = new LargeObjectIterator(heap_->lo_space(), size_func_);
-      break;
-  }
-
-  // Return the newly allocated iterator;
-  DCHECK(iterator_ != NULL);
-  return iterator_;
-}
-
-
-class HeapObjectsFilter {
- public:
-  virtual ~HeapObjectsFilter() {}
-  virtual bool SkipObject(HeapObject* object) = 0;
-};
-
-
-class UnreachableObjectsFilter : public HeapObjectsFilter {
- public:
-  explicit UnreachableObjectsFilter(Heap* heap) : heap_(heap) {
-    MarkReachableObjects();
-  }
-
-  ~UnreachableObjectsFilter() {
-    heap_->mark_compact_collector()->ClearMarkbits();
-  }
-
-  bool SkipObject(HeapObject* object) {
-    MarkBit mark_bit = Marking::MarkBitFrom(object);
-    return !mark_bit.Get();
-  }
-
- private:
-  class MarkingVisitor : public ObjectVisitor {
-   public:
-    MarkingVisitor() : marking_stack_(10) {}
-
-    void VisitPointers(Object** start, Object** end) {
-      for (Object** p = start; p < end; p++) {
-        if (!(*p)->IsHeapObject()) continue;
-        HeapObject* obj = HeapObject::cast(*p);
-        MarkBit mark_bit = Marking::MarkBitFrom(obj);
-        if (!mark_bit.Get()) {
-          mark_bit.Set();
-          marking_stack_.Add(obj);
-        }
-      }
-    }
-
-    void TransitiveClosure() {
-      while (!marking_stack_.is_empty()) {
-        HeapObject* obj = marking_stack_.RemoveLast();
-        obj->Iterate(this);
-      }
-    }
-
-   private:
-    List<HeapObject*> marking_stack_;
-  };
-
-  void MarkReachableObjects() {
-    MarkingVisitor visitor;
-    heap_->IterateRoots(&visitor, VISIT_ALL);
-    visitor.TransitiveClosure();
-  }
-
-  Heap* heap_;
-  DisallowHeapAllocation no_allocation_;
-};
-
-
-HeapIterator::HeapIterator(Heap* heap)
-    : make_heap_iterable_helper_(heap),
-      no_heap_allocation_(),
-      heap_(heap),
-      filtering_(HeapIterator::kNoFiltering),
-      filter_(NULL) {
-  Init();
-}
-
-
-HeapIterator::HeapIterator(Heap* heap,
-                           HeapIterator::HeapObjectsFiltering filtering)
-    : make_heap_iterable_helper_(heap),
-      no_heap_allocation_(),
-      heap_(heap),
-      filtering_(filtering),
-      filter_(NULL) {
-  Init();
-}
-
-
-HeapIterator::~HeapIterator() {
-  Shutdown();
-}
-
-
-void HeapIterator::Init() {
-  // Start the iteration.
-  space_iterator_ = new SpaceIterator(heap_);
-  switch (filtering_) {
-    case kFilterUnreachable:
-      filter_ = new UnreachableObjectsFilter(heap_);
-      break;
-    default:
-      break;
-  }
-  object_iterator_ = space_iterator_->next();
-}
-
-
-void HeapIterator::Shutdown() {
-#ifdef DEBUG
-  // Assert that in filtering mode we have iterated through all
-  // objects. Otherwise, heap will be left in an inconsistent state.
-  if (filtering_ != kNoFiltering) {
-    DCHECK(object_iterator_ == NULL);
-  }
-#endif
-  // Make sure the last iterator is deallocated.
-  delete space_iterator_;
-  space_iterator_ = NULL;
-  object_iterator_ = NULL;
-  delete filter_;
-  filter_ = NULL;
-}
-
-
-HeapObject* HeapIterator::next() {
-  if (filter_ == NULL) return NextObject();
-
-  HeapObject* obj = NextObject();
-  while (obj != NULL && filter_->SkipObject(obj)) obj = NextObject();
-  return obj;
-}
-
-
-HeapObject* HeapIterator::NextObject() {
-  // No iterator means we are done.
-  if (object_iterator_ == NULL) return NULL;
-
-  if (HeapObject* obj = object_iterator_->next_object()) {
-    // If the current iterator has more objects we are fine.
-    return obj;
-  } else {
-    // Go though the spaces looking for one that has objects.
-    while (space_iterator_->has_next()) {
-      object_iterator_ = space_iterator_->next();
-      if (HeapObject* obj = object_iterator_->next_object()) {
-        return obj;
-      }
-    }
-  }
-  // Done with the last space.
-  object_iterator_ = NULL;
-  return NULL;
-}
-
-
-void HeapIterator::reset() {
-  // Restart the iterator.
-  Shutdown();
-  Init();
-}
-
-
-#ifdef DEBUG
-
-Object* const PathTracer::kAnyGlobalObject = NULL;
-
-class PathTracer::MarkVisitor: public ObjectVisitor {
- public:
-  explicit MarkVisitor(PathTracer* tracer) : tracer_(tracer) {}
-  void VisitPointers(Object** start, Object** end) {
-    // Scan all HeapObject pointers in [start, end)
-    for (Object** p = start; !tracer_->found() && (p < end); p++) {
-      if ((*p)->IsHeapObject())
-        tracer_->MarkRecursively(p, this);
-    }
-  }
-
- private:
-  PathTracer* tracer_;
-};
-
-
-class PathTracer::UnmarkVisitor: public ObjectVisitor {
- public:
-  explicit UnmarkVisitor(PathTracer* tracer) : tracer_(tracer) {}
-  void VisitPointers(Object** start, Object** end) {
-    // Scan all HeapObject pointers in [start, end)
-    for (Object** p = start; p < end; p++) {
-      if ((*p)->IsHeapObject())
-        tracer_->UnmarkRecursively(p, this);
-    }
-  }
-
- private:
-  PathTracer* tracer_;
-};
-
-
-void PathTracer::VisitPointers(Object** start, Object** end) {
-  bool done = ((what_to_find_ == FIND_FIRST) && found_target_);
-  // Visit all HeapObject pointers in [start, end)
-  for (Object** p = start; !done && (p < end); p++) {
-    if ((*p)->IsHeapObject()) {
-      TracePathFrom(p);
-      done = ((what_to_find_ == FIND_FIRST) && found_target_);
-    }
-  }
-}
-
-
-void PathTracer::Reset() {
-  found_target_ = false;
-  object_stack_.Clear();
-}
-
-
-void PathTracer::TracePathFrom(Object** root) {
-  DCHECK((search_target_ == kAnyGlobalObject) ||
-         search_target_->IsHeapObject());
-  found_target_in_trace_ = false;
-  Reset();
-
-  MarkVisitor mark_visitor(this);
-  MarkRecursively(root, &mark_visitor);
-
-  UnmarkVisitor unmark_visitor(this);
-  UnmarkRecursively(root, &unmark_visitor);
-
-  ProcessResults();
-}
-
-
-static bool SafeIsNativeContext(HeapObject* obj) {
-  return obj->map() == obj->GetHeap()->raw_unchecked_native_context_map();
-}
-
-
-void PathTracer::MarkRecursively(Object** p, MarkVisitor* mark_visitor) {
-  if (!(*p)->IsHeapObject()) return;
-
-  HeapObject* obj = HeapObject::cast(*p);
-
-  MapWord map_word = obj->map_word();
-  if (!map_word.ToMap()->IsHeapObject()) return;  // visited before
-
-  if (found_target_in_trace_) return;  // stop if target found
-  object_stack_.Add(obj);
-  if (((search_target_ == kAnyGlobalObject) && obj->IsJSGlobalObject()) ||
-      (obj == search_target_)) {
-    found_target_in_trace_ = true;
-    found_target_ = true;
-    return;
-  }
-
-  bool is_native_context = SafeIsNativeContext(obj);
-
-  // not visited yet
-  Map* map = Map::cast(map_word.ToMap());
-
-  MapWord marked_map_word =
-      MapWord::FromRawValue(obj->map_word().ToRawValue() + kMarkTag);
-  obj->set_map_word(marked_map_word);
-
-  // Scan the object body.
-  if (is_native_context && (visit_mode_ == VISIT_ONLY_STRONG)) {
-    // This is specialized to scan Context's properly.
-    Object** start = reinterpret_cast<Object**>(obj->address() +
-                                                Context::kHeaderSize);
-    Object** end = reinterpret_cast<Object**>(obj->address() +
-        Context::kHeaderSize + Context::FIRST_WEAK_SLOT * kPointerSize);
-    mark_visitor->VisitPointers(start, end);
-  } else {
-    obj->IterateBody(map->instance_type(), obj->SizeFromMap(map), mark_visitor);
-  }
-
-  // Scan the map after the body because the body is a lot more interesting
-  // when doing leak detection.
-  MarkRecursively(reinterpret_cast<Object**>(&map), mark_visitor);
-
-  if (!found_target_in_trace_) {  // don't pop if found the target
-    object_stack_.RemoveLast();
-  }
-}
-
-
-void PathTracer::UnmarkRecursively(Object** p, UnmarkVisitor* unmark_visitor) {
-  if (!(*p)->IsHeapObject()) return;
-
-  HeapObject* obj = HeapObject::cast(*p);
-
-  MapWord map_word = obj->map_word();
-  if (map_word.ToMap()->IsHeapObject()) return;  // unmarked already
-
-  MapWord unmarked_map_word =
-      MapWord::FromRawValue(map_word.ToRawValue() - kMarkTag);
-  obj->set_map_word(unmarked_map_word);
-
-  Map* map = Map::cast(unmarked_map_word.ToMap());
-
-  UnmarkRecursively(reinterpret_cast<Object**>(&map), unmark_visitor);
-
-  obj->IterateBody(map->instance_type(), obj->SizeFromMap(map), unmark_visitor);
-}
-
-
-void PathTracer::ProcessResults() {
-  if (found_target_) {
-    OFStream os(stdout);
-    os << "=====================================\n"
-       << "====        Path to object       ====\n"
-       << "=====================================\n\n";
-
-    DCHECK(!object_stack_.is_empty());
-    for (int i = 0; i < object_stack_.length(); i++) {
-      if (i > 0) os << "\n     |\n     |\n     V\n\n";
-      object_stack_[i]->Print(os);
-    }
-    os << "=====================================\n";
-  }
-}
-
-
-// Triggers a depth-first traversal of reachable objects from one
-// given root object and finds a path to a specific heap object and
-// prints it.
-void Heap::TracePathToObjectFrom(Object* target, Object* root) {
-  PathTracer tracer(target, PathTracer::FIND_ALL, VISIT_ALL);
-  tracer.VisitPointer(&root);
-}
-
-
-// Triggers a depth-first traversal of reachable objects from roots
-// and finds a path to a specific heap object and prints it.
-void Heap::TracePathToObject(Object* target) {
-  PathTracer tracer(target, PathTracer::FIND_ALL, VISIT_ALL);
-  IterateRoots(&tracer, VISIT_ONLY_STRONG);
-}
-
-
-// Triggers a depth-first traversal of reachable objects from roots
-// and finds a path to any global object and prints it. Useful for
-// determining the source for leaks of global objects.
-void Heap::TracePathToGlobal() {
-  PathTracer tracer(PathTracer::kAnyGlobalObject,
-                    PathTracer::FIND_ALL,
-                    VISIT_ALL);
-  IterateRoots(&tracer, VISIT_ONLY_STRONG);
-}
-#endif
-
-
-void Heap::UpdateCumulativeGCStatistics(double duration,
-                                        double spent_in_mutator,
-                                        double marking_time) {
-  if (FLAG_print_cumulative_gc_stat) {
-    total_gc_time_ms_ += duration;
-    max_gc_pause_ = Max(max_gc_pause_, duration);
-    max_alive_after_gc_ = Max(max_alive_after_gc_, SizeOfObjects());
-    min_in_mutator_ = Min(min_in_mutator_, spent_in_mutator);
-  } else if (FLAG_trace_gc_verbose) {
-    total_gc_time_ms_ += duration;
-  }
-
-  marking_time_ += marking_time;
-}
-
-
-int KeyedLookupCache::Hash(Handle<Map> map, Handle<Name> name) {
-  DisallowHeapAllocation no_gc;
-  // Uses only lower 32 bits if pointers are larger.
-  uintptr_t addr_hash =
-      static_cast<uint32_t>(reinterpret_cast<uintptr_t>(*map)) >> kMapHashShift;
-  return static_cast<uint32_t>((addr_hash ^ name->Hash()) & kCapacityMask);
-}
-
-
-int KeyedLookupCache::Lookup(Handle<Map> map, Handle<Name> name) {
-  DisallowHeapAllocation no_gc;
-  int index = (Hash(map, name) & kHashMask);
-  for (int i = 0; i < kEntriesPerBucket; i++) {
-    Key& key = keys_[index + i];
-    if ((key.map == *map) && key.name->Equals(*name)) {
-      return field_offsets_[index + i];
-    }
-  }
-  return kNotFound;
-}
-
-
-void KeyedLookupCache::Update(Handle<Map> map,
-                              Handle<Name> name,
-                              int field_offset) {
-  DisallowHeapAllocation no_gc;
-  if (!name->IsUniqueName()) {
-    if (!StringTable::InternalizeStringIfExists(name->GetIsolate(),
-                                                Handle<String>::cast(name)).
-        ToHandle(&name)) {
-      return;
-    }
-  }
-  // This cache is cleared only between mark compact passes, so we expect the
-  // cache to only contain old space names.
-  DCHECK(!map->GetIsolate()->heap()->InNewSpace(*name));
-
-  int index = (Hash(map, name) & kHashMask);
-  // After a GC there will be free slots, so we use them in order (this may
-  // help to get the most frequently used one in position 0).
-  for (int i = 0; i< kEntriesPerBucket; i++) {
-    Key& key = keys_[index];
-    Object* free_entry_indicator = NULL;
-    if (key.map == free_entry_indicator) {
-      key.map = *map;
-      key.name = *name;
-      field_offsets_[index + i] = field_offset;
-      return;
-    }
-  }
-  // No free entry found in this bucket, so we move them all down one and
-  // put the new entry at position zero.
-  for (int i = kEntriesPerBucket - 1; i > 0; i--) {
-    Key& key = keys_[index + i];
-    Key& key2 = keys_[index + i - 1];
-    key = key2;
-    field_offsets_[index + i] = field_offsets_[index + i - 1];
-  }
-
-  // Write the new first entry.
-  Key& key = keys_[index];
-  key.map = *map;
-  key.name = *name;
-  field_offsets_[index] = field_offset;
-}
-
-
-void KeyedLookupCache::Clear() {
-  for (int index = 0; index < kLength; index++) keys_[index].map = NULL;
-}
-
-
-void DescriptorLookupCache::Clear() {
-  for (int index = 0; index < kLength; index++) keys_[index].source = NULL;
-}
-
-
-void ExternalStringTable::CleanUp() {
-  int last = 0;
-  for (int i = 0; i < new_space_strings_.length(); ++i) {
-    if (new_space_strings_[i] == heap_->the_hole_value()) {
-      continue;
-    }
-    DCHECK(new_space_strings_[i]->IsExternalString());
-    if (heap_->InNewSpace(new_space_strings_[i])) {
-      new_space_strings_[last++] = new_space_strings_[i];
-    } else {
-      old_space_strings_.Add(new_space_strings_[i]);
-    }
-  }
-  new_space_strings_.Rewind(last);
-  new_space_strings_.Trim();
-
-  last = 0;
-  for (int i = 0; i < old_space_strings_.length(); ++i) {
-    if (old_space_strings_[i] == heap_->the_hole_value()) {
-      continue;
-    }
-    DCHECK(old_space_strings_[i]->IsExternalString());
-    DCHECK(!heap_->InNewSpace(old_space_strings_[i]));
-    old_space_strings_[last++] = old_space_strings_[i];
-  }
-  old_space_strings_.Rewind(last);
-  old_space_strings_.Trim();
-#ifdef VERIFY_HEAP
-  if (FLAG_verify_heap) {
-    Verify();
-  }
-#endif
-}
-
-
-void ExternalStringTable::TearDown() {
-  for (int i = 0; i < new_space_strings_.length(); ++i) {
-    heap_->FinalizeExternalString(ExternalString::cast(new_space_strings_[i]));
-  }
-  new_space_strings_.Free();
-  for (int i = 0; i < old_space_strings_.length(); ++i) {
-    heap_->FinalizeExternalString(ExternalString::cast(old_space_strings_[i]));
-  }
-  old_space_strings_.Free();
-}
-
-
-void Heap::QueueMemoryChunkForFree(MemoryChunk* chunk) {
-  chunk->set_next_chunk(chunks_queued_for_free_);
-  chunks_queued_for_free_ = chunk;
-}
-
-
-void Heap::FreeQueuedChunks() {
-  if (chunks_queued_for_free_ == NULL) return;
-  MemoryChunk* next;
-  MemoryChunk* chunk;
-  for (chunk = chunks_queued_for_free_; chunk != NULL; chunk = next) {
-    next = chunk->next_chunk();
-    chunk->SetFlag(MemoryChunk::ABOUT_TO_BE_FREED);
-
-    if (chunk->owner()->identity() == LO_SPACE) {
-      // StoreBuffer::Filter relies on MemoryChunk::FromAnyPointerAddress.
-      // If FromAnyPointerAddress encounters a slot that belongs to a large
-      // chunk queued for deletion it will fail to find the chunk because
-      // it try to perform a search in the list of pages owned by of the large
-      // object space and queued chunks were detached from that list.
-      // To work around this we split large chunk into normal kPageSize aligned
-      // pieces and initialize size, owner and flags field of every piece.
-      // If FromAnyPointerAddress encounters a slot that belongs to one of
-      // these smaller pieces it will treat it as a slot on a normal Page.
-      Address chunk_end = chunk->address() + chunk->size();
-      MemoryChunk* inner = MemoryChunk::FromAddress(
-          chunk->address() + Page::kPageSize);
-      MemoryChunk* inner_last = MemoryChunk::FromAddress(chunk_end - 1);
-      while (inner <= inner_last) {
-        // Size of a large chunk is always a multiple of
-        // OS::AllocateAlignment() so there is always
-        // enough space for a fake MemoryChunk header.
-        Address area_end = Min(inner->address() + Page::kPageSize, chunk_end);
-        // Guard against overflow.
-        if (area_end < inner->address()) area_end = chunk_end;
-        inner->SetArea(inner->address(), area_end);
-        inner->set_size(Page::kPageSize);
-        inner->set_owner(lo_space());
-        inner->SetFlag(MemoryChunk::ABOUT_TO_BE_FREED);
-        inner = MemoryChunk::FromAddress(
-            inner->address() + Page::kPageSize);
-      }
-    }
-  }
-  isolate_->heap()->store_buffer()->Compact();
-  isolate_->heap()->store_buffer()->Filter(MemoryChunk::ABOUT_TO_BE_FREED);
-  for (chunk = chunks_queued_for_free_; chunk != NULL; chunk = next) {
-    next = chunk->next_chunk();
-    isolate_->memory_allocator()->Free(chunk);
-  }
-  chunks_queued_for_free_ = NULL;
-}
-
-
-void Heap::RememberUnmappedPage(Address page, bool compacted) {
-  uintptr_t p = reinterpret_cast<uintptr_t>(page);
-  // Tag the page pointer to make it findable in the dump file.
-  if (compacted) {
-    p ^= 0xc1ead & (Page::kPageSize - 1);  // Cleared.
-  } else {
-    p ^= 0x1d1ed & (Page::kPageSize - 1);  // I died.
-  }
-  remembered_unmapped_pages_[remembered_unmapped_pages_index_] =
-      reinterpret_cast<Address>(p);
-  remembered_unmapped_pages_index_++;
-  remembered_unmapped_pages_index_ %= kRememberedUnmappedPages;
-}
-
-
-void Heap::ClearObjectStats(bool clear_last_time_stats) {
-  memset(object_counts_, 0, sizeof(object_counts_));
-  memset(object_sizes_, 0, sizeof(object_sizes_));
-  if (clear_last_time_stats) {
-    memset(object_counts_last_time_, 0, sizeof(object_counts_last_time_));
-    memset(object_sizes_last_time_, 0, sizeof(object_sizes_last_time_));
-  }
-}
-
-
-static base::LazyMutex checkpoint_object_stats_mutex = LAZY_MUTEX_INITIALIZER;
-
-
-void Heap::CheckpointObjectStats() {
-  base::LockGuard<base::Mutex> lock_guard(
-      checkpoint_object_stats_mutex.Pointer());
-  Counters* counters = isolate()->counters();
-#define ADJUST_LAST_TIME_OBJECT_COUNT(name)                                    \
-  counters->count_of_##name()->Increment(                                      \
-      static_cast<int>(object_counts_[name]));                                 \
-  counters->count_of_##name()->Decrement(                                      \
-      static_cast<int>(object_counts_last_time_[name]));                       \
-  counters->size_of_##name()->Increment(                                       \
-      static_cast<int>(object_sizes_[name]));                                  \
-  counters->size_of_##name()->Decrement(                                       \
-      static_cast<int>(object_sizes_last_time_[name]));
-  INSTANCE_TYPE_LIST(ADJUST_LAST_TIME_OBJECT_COUNT)
-#undef ADJUST_LAST_TIME_OBJECT_COUNT
-  int index;
-#define ADJUST_LAST_TIME_OBJECT_COUNT(name)               \
-  index = FIRST_CODE_KIND_SUB_TYPE + Code::name;          \
-  counters->count_of_CODE_TYPE_##name()->Increment(       \
-      static_cast<int>(object_counts_[index]));           \
-  counters->count_of_CODE_TYPE_##name()->Decrement(       \
-      static_cast<int>(object_counts_last_time_[index])); \
-  counters->size_of_CODE_TYPE_##name()->Increment(        \
-      static_cast<int>(object_sizes_[index]));            \
-  counters->size_of_CODE_TYPE_##name()->Decrement(        \
-      static_cast<int>(object_sizes_last_time_[index]));
-  CODE_KIND_LIST(ADJUST_LAST_TIME_OBJECT_COUNT)
-#undef ADJUST_LAST_TIME_OBJECT_COUNT
-#define ADJUST_LAST_TIME_OBJECT_COUNT(name)               \
-  index = FIRST_FIXED_ARRAY_SUB_TYPE + name;              \
-  counters->count_of_FIXED_ARRAY_##name()->Increment(     \
-      static_cast<int>(object_counts_[index]));           \
-  counters->count_of_FIXED_ARRAY_##name()->Decrement(     \
-      static_cast<int>(object_counts_last_time_[index])); \
-  counters->size_of_FIXED_ARRAY_##name()->Increment(      \
-      static_cast<int>(object_sizes_[index]));            \
-  counters->size_of_FIXED_ARRAY_##name()->Decrement(      \
-      static_cast<int>(object_sizes_last_time_[index]));
-  FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(ADJUST_LAST_TIME_OBJECT_COUNT)
-#undef ADJUST_LAST_TIME_OBJECT_COUNT
-#define ADJUST_LAST_TIME_OBJECT_COUNT(name)                                   \
-  index =                                                                     \
-      FIRST_CODE_AGE_SUB_TYPE + Code::k##name##CodeAge - Code::kFirstCodeAge; \
-  counters->count_of_CODE_AGE_##name()->Increment(                            \
-      static_cast<int>(object_counts_[index]));                               \
-  counters->count_of_CODE_AGE_##name()->Decrement(                            \
-      static_cast<int>(object_counts_last_time_[index]));                     \
-  counters->size_of_CODE_AGE_##name()->Increment(                             \
-      static_cast<int>(object_sizes_[index]));                                \
-  counters->size_of_CODE_AGE_##name()->Decrement(                             \
-      static_cast<int>(object_sizes_last_time_[index]));
-  CODE_AGE_LIST_COMPLETE(ADJUST_LAST_TIME_OBJECT_COUNT)
-#undef ADJUST_LAST_TIME_OBJECT_COUNT
-
-  MemCopy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
-  MemCopy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
-  ClearObjectStats();
-}
-
-} }  // namespace v8::internal