deps: update v8 to 3.28.73

Reviewed-By: Fedor Indutny <fedor@indutny.com>
PR-URL: https://github.com/joyent/node/pull/8476

1 files changed, 0 insertions, 3120 deletions

diff --git a/deps/v8/src/spaces.cc b/deps/v8/src/spaces.cc
deleted file mode 100644
index fd319ab717..0000000000
--- a/deps/v8/src/spaces.cc
+++ /dev/null
@@ -1,3120 +0,0 @@
-// Copyright 2011 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 "v8.h"
-
-#include "full-codegen.h"
-#include "macro-assembler.h"
-#include "mark-compact.h"
-#include "msan.h"
-#include "platform.h"
-
-namespace v8 {
-namespace internal {
-
-
-// ----------------------------------------------------------------------------
-// HeapObjectIterator
-
-HeapObjectIterator::HeapObjectIterator(PagedSpace* space) {
-  // You can't actually iterate over the anchor page.  It is not a real page,
-  // just an anchor for the double linked page list.  Initialize as if we have
-  // reached the end of the anchor page, then the first iteration will move on
-  // to the first page.
-  Initialize(space,
-             NULL,
-             NULL,
-             kAllPagesInSpace,
-             NULL);
-}
-
-
-HeapObjectIterator::HeapObjectIterator(PagedSpace* space,
-                                       HeapObjectCallback size_func) {
-  // You can't actually iterate over the anchor page.  It is not a real page,
-  // just an anchor for the double linked page list.  Initialize the current
-  // address and end as NULL, then the first iteration will move on
-  // to the first page.
-  Initialize(space,
-             NULL,
-             NULL,
-             kAllPagesInSpace,
-             size_func);
-}
-
-
-HeapObjectIterator::HeapObjectIterator(Page* page,
-                                       HeapObjectCallback size_func) {
-  Space* owner = page->owner();
-  ASSERT(owner == page->heap()->old_pointer_space() ||
-         owner == page->heap()->old_data_space() ||
-         owner == page->heap()->map_space() ||
-         owner == page->heap()->cell_space() ||
-         owner == page->heap()->property_cell_space() ||
-         owner == page->heap()->code_space());
-  Initialize(reinterpret_cast<PagedSpace*>(owner),
-             page->area_start(),
-             page->area_end(),
-             kOnePageOnly,
-             size_func);
-  ASSERT(page->WasSweptPrecisely());
-}
-
-
-void HeapObjectIterator::Initialize(PagedSpace* space,
-                                    Address cur, Address end,
-                                    HeapObjectIterator::PageMode mode,
-                                    HeapObjectCallback size_f) {
-  // Check that we actually can iterate this space.
-  ASSERT(!space->was_swept_conservatively());
-
-  space_ = space;
-  cur_addr_ = cur;
-  cur_end_ = end;
-  page_mode_ = mode;
-  size_func_ = size_f;
-}
-
-
-// We have hit the end of the page and should advance to the next block of
-// objects.  This happens at the end of the page.
-bool HeapObjectIterator::AdvanceToNextPage() {
-  ASSERT(cur_addr_ == cur_end_);
-  if (page_mode_ == kOnePageOnly) return false;
-  Page* cur_page;
-  if (cur_addr_ == NULL) {
-    cur_page = space_->anchor();
-  } else {
-    cur_page = Page::FromAddress(cur_addr_ - 1);
-    ASSERT(cur_addr_ == cur_page->area_end());
-  }
-  cur_page = cur_page->next_page();
-  if (cur_page == space_->anchor()) return false;
-  cur_addr_ = cur_page->area_start();
-  cur_end_ = cur_page->area_end();
-  ASSERT(cur_page->WasSweptPrecisely());
-  return true;
-}
-
-
-// -----------------------------------------------------------------------------
-// CodeRange
-
-
-CodeRange::CodeRange(Isolate* isolate)
-    : isolate_(isolate),
-      code_range_(NULL),
-      free_list_(0),
-      allocation_list_(0),
-      current_allocation_block_index_(0) {
-}
-
-
-bool CodeRange::SetUp(size_t requested) {
-  ASSERT(code_range_ == NULL);
-
-  if (requested == 0) {
-    // On 64-bit platform(s), we put all code objects in a 512 MB range of
-    // virtual address space, so that they can call each other with near calls.
-    if (kIs64BitArch) {
-      requested = 512 * MB;
-    } else {
-      return true;
-    }
-  }
-
-  code_range_ = new VirtualMemory(requested);
-  CHECK(code_range_ != NULL);
-  if (!code_range_->IsReserved()) {
-    delete code_range_;
-    code_range_ = NULL;
-    return false;
-  }
-
-  // We are sure that we have mapped a block of requested addresses.
-  ASSERT(code_range_->size() == requested);
-  LOG(isolate_,
-      NewEvent("CodeRange", code_range_->address(), requested));
-  Address base = reinterpret_cast<Address>(code_range_->address());
-  Address aligned_base =
-      RoundUp(reinterpret_cast<Address>(code_range_->address()),
-              MemoryChunk::kAlignment);
-  size_t size = code_range_->size() - (aligned_base - base);
-  allocation_list_.Add(FreeBlock(aligned_base, size));
-  current_allocation_block_index_ = 0;
-  return true;
-}
-
-
-int CodeRange::CompareFreeBlockAddress(const FreeBlock* left,
-                                       const FreeBlock* right) {
-  // The entire point of CodeRange is that the difference between two
-  // addresses in the range can be represented as a signed 32-bit int,
-  // so the cast is semantically correct.
-  return static_cast<int>(left->start - right->start);
-}
-
-
-bool CodeRange::GetNextAllocationBlock(size_t requested) {
-  for (current_allocation_block_index_++;
-       current_allocation_block_index_ < allocation_list_.length();
-       current_allocation_block_index_++) {
-    if (requested <= allocation_list_[current_allocation_block_index_].size) {
-      return true;  // Found a large enough allocation block.
-    }
-  }
-
-  // Sort and merge the free blocks on the free list and the allocation list.
-  free_list_.AddAll(allocation_list_);
-  allocation_list_.Clear();
-  free_list_.Sort(&CompareFreeBlockAddress);
-  for (int i = 0; i < free_list_.length();) {
-    FreeBlock merged = free_list_[i];
-    i++;
-    // Add adjacent free blocks to the current merged block.
-    while (i < free_list_.length() &&
-           free_list_[i].start == merged.start + merged.size) {
-      merged.size += free_list_[i].size;
-      i++;
-    }
-    if (merged.size > 0) {
-      allocation_list_.Add(merged);
-    }
-  }
-  free_list_.Clear();
-
-  for (current_allocation_block_index_ = 0;
-       current_allocation_block_index_ < allocation_list_.length();
-       current_allocation_block_index_++) {
-    if (requested <= allocation_list_[current_allocation_block_index_].size) {
-      return true;  // Found a large enough allocation block.
-    }
-  }
-  current_allocation_block_index_ = 0;
-  // Code range is full or too fragmented.
-  return false;
-}
-
-
-Address CodeRange::AllocateRawMemory(const size_t requested_size,
-                                     const size_t commit_size,
-                                     size_t* allocated) {
-  ASSERT(commit_size <= requested_size);
-  ASSERT(current_allocation_block_index_ < allocation_list_.length());
-  if (requested_size > allocation_list_[current_allocation_block_index_].size) {
-    // Find an allocation block large enough.
-    if (!GetNextAllocationBlock(requested_size)) return NULL;
-  }
-  // Commit the requested memory at the start of the current allocation block.
-  size_t aligned_requested = RoundUp(requested_size, MemoryChunk::kAlignment);
-  FreeBlock current = allocation_list_[current_allocation_block_index_];
-  if (aligned_requested >= (current.size - Page::kPageSize)) {
-    // Don't leave a small free block, useless for a large object or chunk.
-    *allocated = current.size;
-  } else {
-    *allocated = aligned_requested;
-  }
-  ASSERT(*allocated <= current.size);
-  ASSERT(IsAddressAligned(current.start, MemoryChunk::kAlignment));
-  if (!isolate_->memory_allocator()->CommitExecutableMemory(code_range_,
-                                                            current.start,
-                                                            commit_size,
-                                                            *allocated)) {
-    *allocated = 0;
-    return NULL;
-  }
-  allocation_list_[current_allocation_block_index_].start += *allocated;
-  allocation_list_[current_allocation_block_index_].size -= *allocated;
-  if (*allocated == current.size) {
-    // This block is used up, get the next one.
-    if (!GetNextAllocationBlock(0)) return NULL;
-  }
-  return current.start;
-}
-
-
-bool CodeRange::CommitRawMemory(Address start, size_t length) {
-  return isolate_->memory_allocator()->CommitMemory(start, length, EXECUTABLE);
-}
-
-
-bool CodeRange::UncommitRawMemory(Address start, size_t length) {
-  return code_range_->Uncommit(start, length);
-}
-
-
-void CodeRange::FreeRawMemory(Address address, size_t length) {
-  ASSERT(IsAddressAligned(address, MemoryChunk::kAlignment));
-  free_list_.Add(FreeBlock(address, length));
-  code_range_->Uncommit(address, length);
-}
-
-
-void CodeRange::TearDown() {
-    delete code_range_;  // Frees all memory in the virtual memory range.
-    code_range_ = NULL;
-    free_list_.Free();
-    allocation_list_.Free();
-}
-
-
-// -----------------------------------------------------------------------------
-// MemoryAllocator
-//
-
-MemoryAllocator::MemoryAllocator(Isolate* isolate)
-    : isolate_(isolate),
-      capacity_(0),
-      capacity_executable_(0),
-      size_(0),
-      size_executable_(0),
-      lowest_ever_allocated_(reinterpret_cast<void*>(-1)),
-      highest_ever_allocated_(reinterpret_cast<void*>(0)) {
-}
-
-
-bool MemoryAllocator::SetUp(intptr_t capacity, intptr_t capacity_executable) {
-  capacity_ = RoundUp(capacity, Page::kPageSize);
-  capacity_executable_ = RoundUp(capacity_executable, Page::kPageSize);
-  ASSERT_GE(capacity_, capacity_executable_);
-
-  size_ = 0;
-  size_executable_ = 0;
-
-  return true;
-}
-
-
-void MemoryAllocator::TearDown() {
-  // Check that spaces were torn down before MemoryAllocator.
-  ASSERT(size_ == 0);
-  // TODO(gc) this will be true again when we fix FreeMemory.
-  // ASSERT(size_executable_ == 0);
-  capacity_ = 0;
-  capacity_executable_ = 0;
-}
-
-
-bool MemoryAllocator::CommitMemory(Address base,
-                                   size_t size,
-                                   Executability executable) {
-  if (!VirtualMemory::CommitRegion(base, size, executable == EXECUTABLE)) {
-    return false;
-  }
-  UpdateAllocatedSpaceLimits(base, base + size);
-  return true;
-}
-
-
-void MemoryAllocator::FreeMemory(VirtualMemory* reservation,
-                                 Executability executable) {
-  // TODO(gc) make code_range part of memory allocator?
-  ASSERT(reservation->IsReserved());
-  size_t size = reservation->size();
-  ASSERT(size_ >= size);
-  size_ -= size;
-
-  isolate_->counters()->memory_allocated()->Decrement(static_cast<int>(size));
-
-  if (executable == EXECUTABLE) {
-    ASSERT(size_executable_ >= size);
-    size_executable_ -= size;
-  }
-  // Code which is part of the code-range does not have its own VirtualMemory.
-  ASSERT(!isolate_->code_range()->contains(
-      static_cast<Address>(reservation->address())));
-  ASSERT(executable == NOT_EXECUTABLE || !isolate_->code_range()->exists());
-  reservation->Release();
-}
-
-
-void MemoryAllocator::FreeMemory(Address base,
-                                 size_t size,
-                                 Executability executable) {
-  // TODO(gc) make code_range part of memory allocator?
-  ASSERT(size_ >= size);
-  size_ -= size;
-
-  isolate_->counters()->memory_allocated()->Decrement(static_cast<int>(size));
-
-  if (executable == EXECUTABLE) {
-    ASSERT(size_executable_ >= size);
-    size_executable_ -= size;
-  }
-  if (isolate_->code_range()->contains(static_cast<Address>(base))) {
-    ASSERT(executable == EXECUTABLE);
-    isolate_->code_range()->FreeRawMemory(base, size);
-  } else {
-    ASSERT(executable == NOT_EXECUTABLE || !isolate_->code_range()->exists());
-    bool result = VirtualMemory::ReleaseRegion(base, size);
-    USE(result);
-    ASSERT(result);
-  }
-}
-
-
-Address MemoryAllocator::ReserveAlignedMemory(size_t size,
-                                              size_t alignment,
-                                              VirtualMemory* controller) {
-  VirtualMemory reservation(size, alignment);
-
-  if (!reservation.IsReserved()) return NULL;
-  size_ += reservation.size();
-  Address base = RoundUp(static_cast<Address>(reservation.address()),
-                         alignment);
-  controller->TakeControl(&reservation);
-  return base;
-}
-
-
-Address MemoryAllocator::AllocateAlignedMemory(size_t reserve_size,
-                                               size_t commit_size,
-                                               size_t alignment,
-                                               Executability executable,
-                                               VirtualMemory* controller) {
-  ASSERT(commit_size <= reserve_size);
-  VirtualMemory reservation;
-  Address base = ReserveAlignedMemory(reserve_size, alignment, &reservation);
-  if (base == NULL) return NULL;
-
-  if (executable == EXECUTABLE) {
-    if (!CommitExecutableMemory(&reservation,
-                                base,
-                                commit_size,
-                                reserve_size)) {
-      base = NULL;
-    }
-  } else {
-    if (reservation.Commit(base, commit_size, false)) {
-      UpdateAllocatedSpaceLimits(base, base + commit_size);
-    } else {
-      base = NULL;
-    }
-  }
-
-  if (base == NULL) {
-    // Failed to commit the body. Release the mapping and any partially
-    // commited regions inside it.
-    reservation.Release();
-    return NULL;
-  }
-
-  controller->TakeControl(&reservation);
-  return base;
-}
-
-
-void Page::InitializeAsAnchor(PagedSpace* owner) {
-  set_owner(owner);
-  set_prev_page(this);
-  set_next_page(this);
-}
-
-
-NewSpacePage* NewSpacePage::Initialize(Heap* heap,
-                                       Address start,
-                                       SemiSpace* semi_space) {
-  Address area_start = start + NewSpacePage::kObjectStartOffset;
-  Address area_end = start + Page::kPageSize;
-
-  MemoryChunk* chunk = MemoryChunk::Initialize(heap,
-                                               start,
-                                               Page::kPageSize,
-                                               area_start,
-                                               area_end,
-                                               NOT_EXECUTABLE,
-                                               semi_space);
-  chunk->set_next_chunk(NULL);
-  chunk->set_prev_chunk(NULL);
-  chunk->initialize_scan_on_scavenge(true);
-  bool in_to_space = (semi_space->id() != kFromSpace);
-  chunk->SetFlag(in_to_space ? MemoryChunk::IN_TO_SPACE
-                             : MemoryChunk::IN_FROM_SPACE);
-  ASSERT(!chunk->IsFlagSet(in_to_space ? MemoryChunk::IN_FROM_SPACE
-                                       : MemoryChunk::IN_TO_SPACE));
-  NewSpacePage* page = static_cast<NewSpacePage*>(chunk);
-  heap->incremental_marking()->SetNewSpacePageFlags(page);
-  return page;
-}
-
-
-void NewSpacePage::InitializeAsAnchor(SemiSpace* semi_space) {
-  set_owner(semi_space);
-  set_next_chunk(this);
-  set_prev_chunk(this);
-  // Flags marks this invalid page as not being in new-space.
-  // All real new-space pages will be in new-space.
-  SetFlags(0, ~0);
-}
-
-
-MemoryChunk* MemoryChunk::Initialize(Heap* heap,
-                                     Address base,
-                                     size_t size,
-                                     Address area_start,
-                                     Address area_end,
-                                     Executability executable,
-                                     Space* owner) {
-  MemoryChunk* chunk = FromAddress(base);
-
-  ASSERT(base == chunk->address());
-
-  chunk->heap_ = heap;
-  chunk->size_ = size;
-  chunk->area_start_ = area_start;
-  chunk->area_end_ = area_end;
-  chunk->flags_ = 0;
-  chunk->set_owner(owner);
-  chunk->InitializeReservedMemory();
-  chunk->slots_buffer_ = NULL;
-  chunk->skip_list_ = NULL;
-  chunk->write_barrier_counter_ = kWriteBarrierCounterGranularity;
-  chunk->progress_bar_ = 0;
-  chunk->high_water_mark_ = static_cast<int>(area_start - base);
-  chunk->set_parallel_sweeping(PARALLEL_SWEEPING_DONE);
-  chunk->available_in_small_free_list_ = 0;
-  chunk->available_in_medium_free_list_ = 0;
-  chunk->available_in_large_free_list_ = 0;
-  chunk->available_in_huge_free_list_ = 0;
-  chunk->non_available_small_blocks_ = 0;
-  chunk->ResetLiveBytes();
-  Bitmap::Clear(chunk);
-  chunk->initialize_scan_on_scavenge(false);
-  chunk->SetFlag(WAS_SWEPT_PRECISELY);
-
-  ASSERT(OFFSET_OF(MemoryChunk, flags_) == kFlagsOffset);
-  ASSERT(OFFSET_OF(MemoryChunk, live_byte_count_) == kLiveBytesOffset);
-
-  if (executable == EXECUTABLE) {
-    chunk->SetFlag(IS_EXECUTABLE);
-  }
-
-  if (owner == heap->old_data_space()) {
-    chunk->SetFlag(CONTAINS_ONLY_DATA);
-  }
-
-  return chunk;
-}
-
-
-// Commit MemoryChunk area to the requested size.
-bool MemoryChunk::CommitArea(size_t requested) {
-  size_t guard_size = IsFlagSet(IS_EXECUTABLE) ?
-                      MemoryAllocator::CodePageGuardSize() : 0;
-  size_t header_size = area_start() - address() - guard_size;
-  size_t commit_size = RoundUp(header_size + requested, OS::CommitPageSize());
-  size_t committed_size = RoundUp(header_size + (area_end() - area_start()),
-                                  OS::CommitPageSize());
-
-  if (commit_size > committed_size) {
-    // Commit size should be less or equal than the reserved size.
-    ASSERT(commit_size <= size() - 2 * guard_size);
-    // Append the committed area.
-    Address start = address() + committed_size + guard_size;
-    size_t length = commit_size - committed_size;
-    if (reservation_.IsReserved()) {
-      Executability executable = IsFlagSet(IS_EXECUTABLE)
-          ? EXECUTABLE : NOT_EXECUTABLE;
-      if (!heap()->isolate()->memory_allocator()->CommitMemory(
-              start, length, executable)) {
-        return false;
-      }
-    } else {
-      CodeRange* code_range = heap_->isolate()->code_range();
-      ASSERT(code_range->exists() && IsFlagSet(IS_EXECUTABLE));
-      if (!code_range->CommitRawMemory(start, length)) return false;
-    }
-
-    if (Heap::ShouldZapGarbage()) {
-      heap_->isolate()->memory_allocator()->ZapBlock(start, length);
-    }
-  } else if (commit_size < committed_size) {
-    ASSERT(commit_size > 0);
-    // Shrink the committed area.
-    size_t length = committed_size - commit_size;
-    Address start = address() + committed_size + guard_size - length;
-    if (reservation_.IsReserved()) {
-      if (!reservation_.Uncommit(start, length)) return false;
-    } else {
-      CodeRange* code_range = heap_->isolate()->code_range();
-      ASSERT(code_range->exists() && IsFlagSet(IS_EXECUTABLE));
-      if (!code_range->UncommitRawMemory(start, length)) return false;
-    }
-  }
-
-  area_end_ = area_start_ + requested;
-  return true;
-}
-
-
-void MemoryChunk::InsertAfter(MemoryChunk* other) {
-  MemoryChunk* other_next = other->next_chunk();
-
-  set_next_chunk(other_next);
-  set_prev_chunk(other);
-  other_next->set_prev_chunk(this);
-  other->set_next_chunk(this);
-}
-
-
-void MemoryChunk::Unlink() {
-  MemoryChunk* next_element = next_chunk();
-  MemoryChunk* prev_element = prev_chunk();
-  next_element->set_prev_chunk(prev_element);
-  prev_element->set_next_chunk(next_element);
-  set_prev_chunk(NULL);
-  set_next_chunk(NULL);
-}
-
-
-MemoryChunk* MemoryAllocator::AllocateChunk(intptr_t reserve_area_size,
-                                            intptr_t commit_area_size,
-                                            Executability executable,
-                                            Space* owner) {
-  ASSERT(commit_area_size <= reserve_area_size);
-
-  size_t chunk_size;
-  Heap* heap = isolate_->heap();
-  Address base = NULL;
-  VirtualMemory reservation;
-  Address area_start = NULL;
-  Address area_end = NULL;
-
-  //
-  // MemoryChunk layout:
-  //
-  //             Executable
-  // +----------------------------+<- base aligned with MemoryChunk::kAlignment
-  // |           Header           |
-  // +----------------------------+<- base + CodePageGuardStartOffset
-  // |           Guard            |
-  // +----------------------------+<- area_start_
-  // |           Area             |
-  // +----------------------------+<- area_end_ (area_start + commit_area_size)
-  // |   Committed but not used   |
-  // +----------------------------+<- aligned at OS page boundary
-  // | Reserved but not committed |
-  // +----------------------------+<- aligned at OS page boundary
-  // |           Guard            |
-  // +----------------------------+<- base + chunk_size
-  //
-  //           Non-executable
-  // +----------------------------+<- base aligned with MemoryChunk::kAlignment
-  // |          Header            |
-  // +----------------------------+<- area_start_ (base + kObjectStartOffset)
-  // |           Area             |
-  // +----------------------------+<- area_end_ (area_start + commit_area_size)
-  // |  Committed but not used    |
-  // +----------------------------+<- aligned at OS page boundary
-  // | Reserved but not committed |
-  // +----------------------------+<- base + chunk_size
-  //
-
-  if (executable == EXECUTABLE) {
-    chunk_size = RoundUp(CodePageAreaStartOffset() + reserve_area_size,
-                         OS::CommitPageSize()) + CodePageGuardSize();
-
-    // Check executable memory limit.
-    if (size_executable_ + chunk_size > capacity_executable_) {
-      LOG(isolate_,
-          StringEvent("MemoryAllocator::AllocateRawMemory",
-                      "V8 Executable Allocation capacity exceeded"));
-      return NULL;
-    }
-
-    // Size of header (not executable) plus area (executable).
-    size_t commit_size = RoundUp(CodePageGuardStartOffset() + commit_area_size,
-                                 OS::CommitPageSize());
-    // Allocate executable memory either from code range or from the
-    // OS.
-    if (isolate_->code_range()->exists()) {
-      base = isolate_->code_range()->AllocateRawMemory(chunk_size,
-                                                       commit_size,
-                                                       &chunk_size);
-      ASSERT(IsAligned(reinterpret_cast<intptr_t>(base),
-                       MemoryChunk::kAlignment));
-      if (base == NULL) return NULL;
-      size_ += chunk_size;
-      // Update executable memory size.
-      size_executable_ += chunk_size;
-    } else {
-      base = AllocateAlignedMemory(chunk_size,
-                                   commit_size,
-                                   MemoryChunk::kAlignment,
-                                   executable,
-                                   &reservation);
-      if (base == NULL) return NULL;
-      // Update executable memory size.
-      size_executable_ += reservation.size();
-    }
-
-    if (Heap::ShouldZapGarbage()) {
-      ZapBlock(base, CodePageGuardStartOffset());
-      ZapBlock(base + CodePageAreaStartOffset(), commit_area_size);
-    }
-
-    area_start = base + CodePageAreaStartOffset();
-    area_end = area_start + commit_area_size;
-  } else {
-    chunk_size = RoundUp(MemoryChunk::kObjectStartOffset + reserve_area_size,
-                         OS::CommitPageSize());
-    size_t commit_size = RoundUp(MemoryChunk::kObjectStartOffset +
-                                 commit_area_size, OS::CommitPageSize());
-    base = AllocateAlignedMemory(chunk_size,
-                                 commit_size,
-                                 MemoryChunk::kAlignment,
-                                 executable,
-                                 &reservation);
-
-    if (base == NULL) return NULL;
-
-    if (Heap::ShouldZapGarbage()) {
-      ZapBlock(base, Page::kObjectStartOffset + commit_area_size);
-    }
-
-    area_start = base + Page::kObjectStartOffset;
-    area_end = area_start + commit_area_size;
-  }
-
-  // Use chunk_size for statistics and callbacks because we assume that they
-  // treat reserved but not-yet committed memory regions of chunks as allocated.
-  isolate_->counters()->memory_allocated()->
-      Increment(static_cast<int>(chunk_size));
-
-  LOG(isolate_, NewEvent("MemoryChunk", base, chunk_size));
-  if (owner != NULL) {
-    ObjectSpace space = static_cast<ObjectSpace>(1 << owner->identity());
-    PerformAllocationCallback(space, kAllocationActionAllocate, chunk_size);
-  }
-
-  MemoryChunk* result = MemoryChunk::Initialize(heap,
-                                                base,
-                                                chunk_size,
-                                                area_start,
-                                                area_end,
-                                                executable,
-                                                owner);
-  result->set_reserved_memory(&reservation);
-  MSAN_MEMORY_IS_INITIALIZED_IN_JIT(base, chunk_size);
-  return result;
-}
-
-
-void Page::ResetFreeListStatistics() {
-  non_available_small_blocks_ = 0;
-  available_in_small_free_list_ = 0;
-  available_in_medium_free_list_ = 0;
-  available_in_large_free_list_ = 0;
-  available_in_huge_free_list_ = 0;
-}
-
-
-Page* MemoryAllocator::AllocatePage(intptr_t size,
-                                    PagedSpace* owner,
-                                    Executability executable) {
-  MemoryChunk* chunk = AllocateChunk(size, size, executable, owner);
-
-  if (chunk == NULL) return NULL;
-
-  return Page::Initialize(isolate_->heap(), chunk, executable, owner);
-}
-
-
-LargePage* MemoryAllocator::AllocateLargePage(intptr_t object_size,
-                                              Space* owner,
-                                              Executability executable) {
-  MemoryChunk* chunk = AllocateChunk(object_size,
-                                     object_size,
-                                     executable,
-                                     owner);
-  if (chunk == NULL) return NULL;
-  return LargePage::Initialize(isolate_->heap(), chunk);
-}
-
-
-void MemoryAllocator::Free(MemoryChunk* chunk) {
-  LOG(isolate_, DeleteEvent("MemoryChunk", chunk));
-  if (chunk->owner() != NULL) {
-    ObjectSpace space =
-        static_cast<ObjectSpace>(1 << chunk->owner()->identity());
-    PerformAllocationCallback(space, kAllocationActionFree, chunk->size());
-  }
-
-  isolate_->heap()->RememberUnmappedPage(
-      reinterpret_cast<Address>(chunk), chunk->IsEvacuationCandidate());
-
-  delete chunk->slots_buffer();
-  delete chunk->skip_list();
-
-  VirtualMemory* reservation = chunk->reserved_memory();
-  if (reservation->IsReserved()) {
-    FreeMemory(reservation, chunk->executable());
-  } else {
-    FreeMemory(chunk->address(),
-               chunk->size(),
-               chunk->executable());
-  }
-}
-
-
-bool MemoryAllocator::CommitBlock(Address start,
-                                  size_t size,
-                                  Executability executable) {
-  if (!CommitMemory(start, size, executable)) return false;
-
-  if (Heap::ShouldZapGarbage()) {
-    ZapBlock(start, size);
-  }
-
-  isolate_->counters()->memory_allocated()->Increment(static_cast<int>(size));
-  return true;
-}
-
-
-bool MemoryAllocator::UncommitBlock(Address start, size_t size) {
-  if (!VirtualMemory::UncommitRegion(start, size)) return false;
-  isolate_->counters()->memory_allocated()->Decrement(static_cast<int>(size));
-  return true;
-}
-
-
-void MemoryAllocator::ZapBlock(Address start, size_t size) {
-  for (size_t s = 0; s + kPointerSize <= size; s += kPointerSize) {
-    Memory::Address_at(start + s) = kZapValue;
-  }
-}
-
-
-void MemoryAllocator::PerformAllocationCallback(ObjectSpace space,
-                                                AllocationAction action,
-                                                size_t size) {
-  for (int i = 0; i < memory_allocation_callbacks_.length(); ++i) {
-    MemoryAllocationCallbackRegistration registration =
-      memory_allocation_callbacks_[i];
-    if ((registration.space & space) == space &&
-        (registration.action & action) == action)
-      registration.callback(space, action, static_cast<int>(size));
-  }
-}
-
-
-bool MemoryAllocator::MemoryAllocationCallbackRegistered(
-    MemoryAllocationCallback callback) {
-  for (int i = 0; i < memory_allocation_callbacks_.length(); ++i) {
-    if (memory_allocation_callbacks_[i].callback == callback) return true;
-  }
-  return false;
-}
-
-
-void MemoryAllocator::AddMemoryAllocationCallback(
-    MemoryAllocationCallback callback,
-    ObjectSpace space,
-    AllocationAction action) {
-  ASSERT(callback != NULL);
-  MemoryAllocationCallbackRegistration registration(callback, space, action);
-  ASSERT(!MemoryAllocator::MemoryAllocationCallbackRegistered(callback));
-  return memory_allocation_callbacks_.Add(registration);
-}
-
-
-void MemoryAllocator::RemoveMemoryAllocationCallback(
-     MemoryAllocationCallback callback) {
-  ASSERT(callback != NULL);
-  for (int i = 0; i < memory_allocation_callbacks_.length(); ++i) {
-    if (memory_allocation_callbacks_[i].callback == callback) {
-      memory_allocation_callbacks_.Remove(i);
-      return;
-    }
-  }
-  UNREACHABLE();
-}
-
-
-#ifdef DEBUG
-void MemoryAllocator::ReportStatistics() {
-  float pct = static_cast<float>(capacity_ - size_) / capacity_;
-  PrintF("  capacity: %" V8_PTR_PREFIX "d"
-             ", used: %" V8_PTR_PREFIX "d"
-             ", available: %%%d\n\n",
-         capacity_, size_, static_cast<int>(pct*100));
-}
-#endif
-
-
-int MemoryAllocator::CodePageGuardStartOffset() {
-  // We are guarding code pages: the first OS page after the header
-  // will be protected as non-writable.
-  return RoundUp(Page::kObjectStartOffset, OS::CommitPageSize());
-}
-
-
-int MemoryAllocator::CodePageGuardSize() {
-  return static_cast<int>(OS::CommitPageSize());
-}
-
-
-int MemoryAllocator::CodePageAreaStartOffset() {
-  // We are guarding code pages: the first OS page after the header
-  // will be protected as non-writable.
-  return CodePageGuardStartOffset() + CodePageGuardSize();
-}
-
-
-int MemoryAllocator::CodePageAreaEndOffset() {
-  // We are guarding code pages: the last OS page will be protected as
-  // non-writable.
-  return Page::kPageSize - static_cast<int>(OS::CommitPageSize());
-}
-
-
-bool MemoryAllocator::CommitExecutableMemory(VirtualMemory* vm,
-                                             Address start,
-                                             size_t commit_size,
-                                             size_t reserved_size) {
-  // Commit page header (not executable).
-  if (!vm->Commit(start,
-                  CodePageGuardStartOffset(),
-                  false)) {
-    return false;
-  }
-
-  // Create guard page after the header.
-  if (!vm->Guard(start + CodePageGuardStartOffset())) {
-    return false;
-  }
-
-  // Commit page body (executable).
-  if (!vm->Commit(start + CodePageAreaStartOffset(),
-                  commit_size - CodePageGuardStartOffset(),
-                  true)) {
-    return false;
-  }
-
-  // Create guard page before the end.
-  if (!vm->Guard(start + reserved_size - CodePageGuardSize())) {
-    return false;
-  }
-
-  UpdateAllocatedSpaceLimits(start,
-                             start + CodePageAreaStartOffset() +
-                             commit_size - CodePageGuardStartOffset());
-  return true;
-}
-
-
-// -----------------------------------------------------------------------------
-// MemoryChunk implementation
-
-void MemoryChunk::IncrementLiveBytesFromMutator(Address address, int by) {
-  MemoryChunk* chunk = MemoryChunk::FromAddress(address);
-  if (!chunk->InNewSpace() && !static_cast<Page*>(chunk)->WasSwept()) {
-    static_cast<PagedSpace*>(chunk->owner())->IncrementUnsweptFreeBytes(-by);
-  }
-  chunk->IncrementLiveBytes(by);
-}
-
-
-// -----------------------------------------------------------------------------
-// PagedSpace implementation
-
-PagedSpace::PagedSpace(Heap* heap,
-                       intptr_t max_capacity,
-                       AllocationSpace id,
-                       Executability executable)
-    : Space(heap, id, executable),
-      free_list_(this),
-      was_swept_conservatively_(false),
-      unswept_free_bytes_(0),
-      end_of_unswept_pages_(NULL) {
-  if (id == CODE_SPACE) {
-    area_size_ = heap->isolate()->memory_allocator()->
-        CodePageAreaSize();
-  } else {
-    area_size_ = Page::kPageSize - Page::kObjectStartOffset;
-  }
-  max_capacity_ = (RoundDown(max_capacity, Page::kPageSize) / Page::kPageSize)
-      * AreaSize();
-  accounting_stats_.Clear();
-
-  allocation_info_.set_top(NULL);
-  allocation_info_.set_limit(NULL);
-
-  anchor_.InitializeAsAnchor(this);
-}
-
-
-bool PagedSpace::SetUp() {
-  return true;
-}
-
-
-bool PagedSpace::HasBeenSetUp() {
-  return true;
-}
-
-
-void PagedSpace::TearDown() {
-  PageIterator iterator(this);
-  while (iterator.has_next()) {
-    heap()->isolate()->memory_allocator()->Free(iterator.next());
-  }
-  anchor_.set_next_page(&anchor_);
-  anchor_.set_prev_page(&anchor_);
-  accounting_stats_.Clear();
-}
-
-
-size_t PagedSpace::CommittedPhysicalMemory() {
-  if (!VirtualMemory::HasLazyCommits()) return CommittedMemory();
-  MemoryChunk::UpdateHighWaterMark(allocation_info_.top());
-  size_t size = 0;
-  PageIterator it(this);
-  while (it.has_next()) {
-    size += it.next()->CommittedPhysicalMemory();
-  }
-  return size;
-}
-
-
-Object* PagedSpace::FindObject(Address addr) {
-  // Note: this function can only be called on precisely swept spaces.
-  ASSERT(!heap()->mark_compact_collector()->in_use());
-
-  if (!Contains(addr)) return Smi::FromInt(0);  // Signaling not found.
-
-  Page* p = Page::FromAddress(addr);
-  HeapObjectIterator it(p, NULL);
-  for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
-    Address cur = obj->address();
-    Address next = cur + obj->Size();
-    if ((cur <= addr) && (addr < next)) return obj;
-  }
-
-  UNREACHABLE();
-  return Smi::FromInt(0);
-}
-
-
-bool PagedSpace::CanExpand() {
-  ASSERT(max_capacity_ % AreaSize() == 0);
-
-  if (Capacity() == max_capacity_) return false;
-
-  ASSERT(Capacity() < max_capacity_);
-
-  // Are we going to exceed capacity for this space?
-  if ((Capacity() + Page::kPageSize) > max_capacity_) return false;
-
-  return true;
-}
-
-
-bool PagedSpace::Expand() {
-  if (!CanExpand()) return false;
-
-  intptr_t size = AreaSize();
-
-  if (anchor_.next_page() == &anchor_) {
-    size = SizeOfFirstPage();
-  }
-
-  Page* p = heap()->isolate()->memory_allocator()->AllocatePage(
-      size, this, executable());
-  if (p == NULL) return false;
-
-  ASSERT(Capacity() <= max_capacity_);
-
-  p->InsertAfter(anchor_.prev_page());
-
-  return true;
-}
-
-
-intptr_t PagedSpace::SizeOfFirstPage() {
-  int size = 0;
-  switch (identity()) {
-    case OLD_POINTER_SPACE:
-      size = 96 * kPointerSize * KB;
-      break;
-    case OLD_DATA_SPACE:
-      size = 192 * KB;
-      break;
-    case MAP_SPACE:
-      size = 16 * kPointerSize * KB;
-      break;
-    case CELL_SPACE:
-      size = 16 * kPointerSize * KB;
-      break;
-    case PROPERTY_CELL_SPACE:
-      size = 8 * kPointerSize * KB;
-      break;
-    case CODE_SPACE:
-      if (heap()->isolate()->code_range()->exists()) {
-        // When code range exists, code pages are allocated in a special way
-        // (from the reserved code range). That part of the code is not yet
-        // upgraded to handle small pages.
-        size = AreaSize();
-      } else {
-        size = RoundUp(
-            480 * KB * FullCodeGenerator::kBootCodeSizeMultiplier / 100,
-            kPointerSize);
-      }
-      break;
-    default:
-      UNREACHABLE();
-  }
-  return Min(size, AreaSize());
-}
-
-
-int PagedSpace::CountTotalPages() {
-  PageIterator it(this);
-  int count = 0;
-  while (it.has_next()) {
-    it.next();
-    count++;
-  }
-  return count;
-}
-
-
-void PagedSpace::ObtainFreeListStatistics(Page* page, SizeStats* sizes) {
-  sizes->huge_size_ = page->available_in_huge_free_list();
-  sizes->small_size_ = page->available_in_small_free_list();
-  sizes->medium_size_ = page->available_in_medium_free_list();
-  sizes->large_size_ = page->available_in_large_free_list();
-}
-
-
-void PagedSpace::ResetFreeListStatistics() {
-  PageIterator page_iterator(this);
-  while (page_iterator.has_next()) {
-    Page* page = page_iterator.next();
-    page->ResetFreeListStatistics();
-  }
-}
-
-
-void PagedSpace::IncreaseCapacity(int size) {
-  accounting_stats_.ExpandSpace(size);
-}
-
-
-void PagedSpace::ReleasePage(Page* page) {
-  ASSERT(page->LiveBytes() == 0);
-  ASSERT(AreaSize() == page->area_size());
-
-  if (page->WasSwept()) {
-    intptr_t size = free_list_.EvictFreeListItems(page);
-    accounting_stats_.AllocateBytes(size);
-    ASSERT_EQ(AreaSize(), static_cast<int>(size));
-  } else {
-    DecreaseUnsweptFreeBytes(page);
-  }
-
-  if (page->IsFlagSet(MemoryChunk::SCAN_ON_SCAVENGE)) {
-    heap()->decrement_scan_on_scavenge_pages();
-    page->ClearFlag(MemoryChunk::SCAN_ON_SCAVENGE);
-  }
-
-  ASSERT(!free_list_.ContainsPageFreeListItems(page));
-
-  if (Page::FromAllocationTop(allocation_info_.top()) == page) {
-    allocation_info_.set_top(NULL);
-    allocation_info_.set_limit(NULL);
-  }
-
-  page->Unlink();
-  if (page->IsFlagSet(MemoryChunk::CONTAINS_ONLY_DATA)) {
-    heap()->isolate()->memory_allocator()->Free(page);
-  } else {
-    heap()->QueueMemoryChunkForFree(page);
-  }
-
-  ASSERT(Capacity() > 0);
-  accounting_stats_.ShrinkSpace(AreaSize());
-}
-
-
-#ifdef DEBUG
-void PagedSpace::Print() { }
-#endif
-
-#ifdef VERIFY_HEAP
-void PagedSpace::Verify(ObjectVisitor* visitor) {
-  // We can only iterate over the pages if they were swept precisely.
-  if (was_swept_conservatively_) return;
-
-  bool allocation_pointer_found_in_space =
-      (allocation_info_.top() == allocation_info_.limit());
-  PageIterator page_iterator(this);
-  while (page_iterator.has_next()) {
-    Page* page = page_iterator.next();
-    CHECK(page->owner() == this);
-    if (page == Page::FromAllocationTop(allocation_info_.top())) {
-      allocation_pointer_found_in_space = true;
-    }
-    CHECK(page->WasSweptPrecisely());
-    HeapObjectIterator it(page, NULL);
-    Address end_of_previous_object = page->area_start();
-    Address top = page->area_end();
-    int black_size = 0;
-    for (HeapObject* object = it.Next(); object != NULL; object = it.Next()) {
-      CHECK(end_of_previous_object <= object->address());
-
-      // The first word should be a map, and we expect all map pointers to
-      // be in map space.
-      Map* map = object->map();
-      CHECK(map->IsMap());
-      CHECK(heap()->map_space()->Contains(map));
-
-      // Perform space-specific object verification.
-      VerifyObject(object);
-
-      // The object itself should look OK.
-      object->ObjectVerify();
-
-      // All the interior pointers should be contained in the heap.
-      int size = object->Size();
-      object->IterateBody(map->instance_type(), size, visitor);
-      if (Marking::IsBlack(Marking::MarkBitFrom(object))) {
-        black_size += size;
-      }
-
-      CHECK(object->address() + size <= top);
-      end_of_previous_object = object->address() + size;
-    }
-    CHECK_LE(black_size, page->LiveBytes());
-  }
-  CHECK(allocation_pointer_found_in_space);
-}
-#endif  // VERIFY_HEAP
-
-// -----------------------------------------------------------------------------
-// NewSpace implementation
-
-
-bool NewSpace::SetUp(int reserved_semispace_capacity,
-                     int maximum_semispace_capacity) {
-  // Set up new space based on the preallocated memory block defined by
-  // start and size. The provided space is divided into two semi-spaces.
-  // To support fast containment testing in the new space, the size of
-  // this chunk must be a power of two and it must be aligned to its size.
-  int initial_semispace_capacity = heap()->InitialSemiSpaceSize();
-
-  size_t size = 2 * reserved_semispace_capacity;
-  Address base =
-      heap()->isolate()->memory_allocator()->ReserveAlignedMemory(
-          size, size, &reservation_);
-  if (base == NULL) return false;
-
-  chunk_base_ = base;
-  chunk_size_ = static_cast<uintptr_t>(size);
-  LOG(heap()->isolate(), NewEvent("InitialChunk", chunk_base_, chunk_size_));
-
-  ASSERT(initial_semispace_capacity <= maximum_semispace_capacity);
-  ASSERT(IsPowerOf2(maximum_semispace_capacity));
-
-  // Allocate and set up the histogram arrays if necessary.
-  allocated_histogram_ = NewArray<HistogramInfo>(LAST_TYPE + 1);
-  promoted_histogram_ = NewArray<HistogramInfo>(LAST_TYPE + 1);
-
-#define SET_NAME(name) allocated_histogram_[name].set_name(#name); \
-                       promoted_histogram_[name].set_name(#name);
-  INSTANCE_TYPE_LIST(SET_NAME)
-#undef SET_NAME
-
-  ASSERT(reserved_semispace_capacity == heap()->ReservedSemiSpaceSize());
-  ASSERT(static_cast<intptr_t>(chunk_size_) >=
-         2 * heap()->ReservedSemiSpaceSize());
-  ASSERT(IsAddressAligned(chunk_base_, 2 * reserved_semispace_capacity, 0));
-
-  to_space_.SetUp(chunk_base_,
-                  initial_semispace_capacity,
-                  maximum_semispace_capacity);
-  from_space_.SetUp(chunk_base_ + reserved_semispace_capacity,
-                    initial_semispace_capacity,
-                    maximum_semispace_capacity);
-  if (!to_space_.Commit()) {
-    return false;
-  }
-  ASSERT(!from_space_.is_committed());  // No need to use memory yet.
-
-  start_ = chunk_base_;
-  address_mask_ = ~(2 * reserved_semispace_capacity - 1);
-  object_mask_ = address_mask_ | kHeapObjectTagMask;
-  object_expected_ = reinterpret_cast<uintptr_t>(start_) | kHeapObjectTag;
-
-  ResetAllocationInfo();
-
-  return true;
-}
-
-
-void NewSpace::TearDown() {
-  if (allocated_histogram_) {
-    DeleteArray(allocated_histogram_);
-    allocated_histogram_ = NULL;
-  }
-  if (promoted_histogram_) {
-    DeleteArray(promoted_histogram_);
-    promoted_histogram_ = NULL;
-  }
-
-  start_ = NULL;
-  allocation_info_.set_top(NULL);
-  allocation_info_.set_limit(NULL);
-
-  to_space_.TearDown();
-  from_space_.TearDown();
-
-  LOG(heap()->isolate(), DeleteEvent("InitialChunk", chunk_base_));
-
-  ASSERT(reservation_.IsReserved());
-  heap()->isolate()->memory_allocator()->FreeMemory(&reservation_,
-                                                    NOT_EXECUTABLE);
-  chunk_base_ = NULL;
-  chunk_size_ = 0;
-}
-
-
-void NewSpace::Flip() {
-  SemiSpace::Swap(&from_space_, &to_space_);
-}
-
-
-void NewSpace::Grow() {
-  // Double the semispace size but only up to maximum capacity.
-  ASSERT(Capacity() < MaximumCapacity());
-  int new_capacity = Min(MaximumCapacity(), 2 * static_cast<int>(Capacity()));
-  if (to_space_.GrowTo(new_capacity)) {
-    // Only grow from space if we managed to grow to-space.
-    if (!from_space_.GrowTo(new_capacity)) {
-      // If we managed to grow to-space but couldn't grow from-space,
-      // attempt to shrink to-space.
-      if (!to_space_.ShrinkTo(from_space_.Capacity())) {
-        // We are in an inconsistent state because we could not
-        // commit/uncommit memory from new space.
-        V8::FatalProcessOutOfMemory("Failed to grow new space.");
-      }
-    }
-  }
-  ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_);
-}
-
-
-void NewSpace::Shrink() {
-  int new_capacity = Max(InitialCapacity(), 2 * SizeAsInt());
-  int rounded_new_capacity = RoundUp(new_capacity, Page::kPageSize);
-  if (rounded_new_capacity < Capacity() &&
-      to_space_.ShrinkTo(rounded_new_capacity))  {
-    // Only shrink from-space if we managed to shrink to-space.
-    from_space_.Reset();
-    if (!from_space_.ShrinkTo(rounded_new_capacity)) {
-      // If we managed to shrink to-space but couldn't shrink from
-      // space, attempt to grow to-space again.
-      if (!to_space_.GrowTo(from_space_.Capacity())) {
-        // We are in an inconsistent state because we could not
-        // commit/uncommit memory from new space.
-        V8::FatalProcessOutOfMemory("Failed to shrink new space.");
-      }
-    }
-  }
-  ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_);
-}
-
-
-void NewSpace::UpdateAllocationInfo() {
-  MemoryChunk::UpdateHighWaterMark(allocation_info_.top());
-  allocation_info_.set_top(to_space_.page_low());
-  allocation_info_.set_limit(to_space_.page_high());
-  UpdateInlineAllocationLimit(0);
-  ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_);
-}
-
-
-void NewSpace::ResetAllocationInfo() {
-  to_space_.Reset();
-  UpdateAllocationInfo();
-  pages_used_ = 0;
-  // Clear all mark-bits in the to-space.
-  NewSpacePageIterator it(&to_space_);
-  while (it.has_next()) {
-    Bitmap::Clear(it.next());
-  }
-}
-
-
-void NewSpace::UpdateInlineAllocationLimit(int size_in_bytes) {
-  if (heap()->inline_allocation_disabled()) {
-    // Lowest limit when linear allocation was disabled.
-    Address high = to_space_.page_high();
-    Address new_top = allocation_info_.top() + size_in_bytes;
-    allocation_info_.set_limit(Min(new_top, high));
-  } else if (inline_allocation_limit_step() == 0) {
-    // Normal limit is the end of the current page.
-    allocation_info_.set_limit(to_space_.page_high());
-  } else {
-    // Lower limit during incremental marking.
-    Address high = to_space_.page_high();
-    Address new_top = allocation_info_.top() + size_in_bytes;
-    Address new_limit = new_top + inline_allocation_limit_step_;
-    allocation_info_.set_limit(Min(new_limit, high));
-  }
-  ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_);
-}
-
-
-bool NewSpace::AddFreshPage() {
-  Address top = allocation_info_.top();
-  if (NewSpacePage::IsAtStart(top)) {
-    // The current page is already empty. Don't try to make another.
-
-    // We should only get here if someone asks to allocate more
-    // than what can be stored in a single page.
-    // TODO(gc): Change the limit on new-space allocation to prevent this
-    // from happening (all such allocations should go directly to LOSpace).
-    return false;
-  }
-  if (!to_space_.AdvancePage()) {
-    // Failed to get a new page in to-space.
-    return false;
-  }
-
-  // Clear remainder of current page.
-  Address limit = NewSpacePage::FromLimit(top)->area_end();
-  if (heap()->gc_state() == Heap::SCAVENGE) {
-    heap()->promotion_queue()->SetNewLimit(limit);
-    heap()->promotion_queue()->ActivateGuardIfOnTheSamePage();
-  }
-
-  int remaining_in_page = static_cast<int>(limit - top);
-  heap()->CreateFillerObjectAt(top, remaining_in_page);
-  pages_used_++;
-  UpdateAllocationInfo();
-
-  return true;
-}
-
-
-AllocationResult NewSpace::SlowAllocateRaw(int size_in_bytes) {
-  Address old_top = allocation_info_.top();
-  Address high = to_space_.page_high();
-  if (allocation_info_.limit() < high) {
-    // Either the limit has been lowered because linear allocation was disabled
-    // or because incremental marking wants to get a chance to do a step. Set
-    // the new limit accordingly.
-    Address new_top = old_top + size_in_bytes;
-    int bytes_allocated = static_cast<int>(new_top - top_on_previous_step_);
-    heap()->incremental_marking()->Step(
-        bytes_allocated, IncrementalMarking::GC_VIA_STACK_GUARD);
-    UpdateInlineAllocationLimit(size_in_bytes);
-    top_on_previous_step_ = new_top;
-    return AllocateRaw(size_in_bytes);
-  } else if (AddFreshPage()) {
-    // Switched to new page. Try allocating again.
-    int bytes_allocated = static_cast<int>(old_top - top_on_previous_step_);
-    heap()->incremental_marking()->Step(
-        bytes_allocated, IncrementalMarking::GC_VIA_STACK_GUARD);
-    top_on_previous_step_ = to_space_.page_low();
-    return AllocateRaw(size_in_bytes);
-  } else {
-    return AllocationResult::Retry();
-  }
-}
-
-
-#ifdef VERIFY_HEAP
-// We do not use the SemiSpaceIterator because verification doesn't assume
-// that it works (it depends on the invariants we are checking).
-void NewSpace::Verify() {
-  // The allocation pointer should be in the space or at the very end.
-  ASSERT_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_);
-
-  // There should be objects packed in from the low address up to the
-  // allocation pointer.
-  Address current = to_space_.first_page()->area_start();
-  CHECK_EQ(current, to_space_.space_start());
-
-  while (current != top()) {
-    if (!NewSpacePage::IsAtEnd(current)) {
-      // The allocation pointer should not be in the middle of an object.
-      CHECK(!NewSpacePage::FromLimit(current)->ContainsLimit(top()) ||
-            current < top());
-
-      HeapObject* object = HeapObject::FromAddress(current);
-
-      // The first word should be a map, and we expect all map pointers to
-      // be in map space.
-      Map* map = object->map();
-      CHECK(map->IsMap());
-      CHECK(heap()->map_space()->Contains(map));
-
-      // The object should not be code or a map.
-      CHECK(!object->IsMap());
-      CHECK(!object->IsCode());
-
-      // The object itself should look OK.
-      object->ObjectVerify();
-
-      // All the interior pointers should be contained in the heap.
-      VerifyPointersVisitor visitor;
-      int size = object->Size();
-      object->IterateBody(map->instance_type(), size, &visitor);
-
-      current += size;
-    } else {
-      // At end of page, switch to next page.
-      NewSpacePage* page = NewSpacePage::FromLimit(current)->next_page();
-      // Next page should be valid.
-      CHECK(!page->is_anchor());
-      current = page->area_start();
-    }
-  }
-
-  // Check semi-spaces.
-  CHECK_EQ(from_space_.id(), kFromSpace);
-  CHECK_EQ(to_space_.id(), kToSpace);
-  from_space_.Verify();
-  to_space_.Verify();
-}
-#endif
-
-// -----------------------------------------------------------------------------
-// SemiSpace implementation
-
-void SemiSpace::SetUp(Address start,
-                      int initial_capacity,
-                      int maximum_capacity) {
-  // Creates a space in the young generation. The constructor does not
-  // allocate memory from the OS.  A SemiSpace is given a contiguous chunk of
-  // memory of size 'capacity' when set up, and does not grow or shrink
-  // otherwise.  In the mark-compact collector, the memory region of the from
-  // space is used as the marking stack. It requires contiguous memory
-  // addresses.
-  ASSERT(maximum_capacity >= Page::kPageSize);
-  initial_capacity_ = RoundDown(initial_capacity, Page::kPageSize);
-  capacity_ = initial_capacity;
-  maximum_capacity_ = RoundDown(maximum_capacity, Page::kPageSize);
-  maximum_committed_ = 0;
-  committed_ = false;
-  start_ = start;
-  address_mask_ = ~(maximum_capacity - 1);
-  object_mask_ = address_mask_ | kHeapObjectTagMask;
-  object_expected_ = reinterpret_cast<uintptr_t>(start) | kHeapObjectTag;
-  age_mark_ = start_;
-}
-
-
-void SemiSpace::TearDown() {
-  start_ = NULL;
-  capacity_ = 0;
-}
-
-
-bool SemiSpace::Commit() {
-  ASSERT(!is_committed());
-  int pages = capacity_ / Page::kPageSize;
-  if (!heap()->isolate()->memory_allocator()->CommitBlock(start_,
-                                                          capacity_,
-                                                          executable())) {
-    return false;
-  }
-
-  NewSpacePage* current = anchor();
-  for (int i = 0; i < pages; i++) {
-    NewSpacePage* new_page =
-      NewSpacePage::Initialize(heap(), start_ + i * Page::kPageSize, this);
-    new_page->InsertAfter(current);
-    current = new_page;
-  }
-
-  SetCapacity(capacity_);
-  committed_ = true;
-  Reset();
-  return true;
-}
-
-
-bool SemiSpace::Uncommit() {
-  ASSERT(is_committed());
-  Address start = start_ + maximum_capacity_ - capacity_;
-  if (!heap()->isolate()->memory_allocator()->UncommitBlock(start, capacity_)) {
-    return false;
-  }
-  anchor()->set_next_page(anchor());
-  anchor()->set_prev_page(anchor());
-
-  committed_ = false;
-  return true;
-}
-
-
-size_t SemiSpace::CommittedPhysicalMemory() {
-  if (!is_committed()) return 0;
-  size_t size = 0;
-  NewSpacePageIterator it(this);
-  while (it.has_next()) {
-    size += it.next()->CommittedPhysicalMemory();
-  }
-  return size;
-}
-
-
-bool SemiSpace::GrowTo(int new_capacity) {
-  if (!is_committed()) {
-    if (!Commit()) return false;
-  }
-  ASSERT((new_capacity & Page::kPageAlignmentMask) == 0);
-  ASSERT(new_capacity <= maximum_capacity_);
-  ASSERT(new_capacity > capacity_);
-  int pages_before = capacity_ / Page::kPageSize;
-  int pages_after = new_capacity / Page::kPageSize;
-
-  size_t delta = new_capacity - capacity_;
-
-  ASSERT(IsAligned(delta, OS::AllocateAlignment()));
-  if (!heap()->isolate()->memory_allocator()->CommitBlock(
-      start_ + capacity_, delta, executable())) {
-    return false;
-  }
-  SetCapacity(new_capacity);
-  NewSpacePage* last_page = anchor()->prev_page();
-  ASSERT(last_page != anchor());
-  for (int i = pages_before; i < pages_after; i++) {
-    Address page_address = start_ + i * Page::kPageSize;
-    NewSpacePage* new_page = NewSpacePage::Initialize(heap(),
-                                                      page_address,
-                                                      this);
-    new_page->InsertAfter(last_page);
-    Bitmap::Clear(new_page);
-    // Duplicate the flags that was set on the old page.
-    new_page->SetFlags(last_page->GetFlags(),
-                       NewSpacePage::kCopyOnFlipFlagsMask);
-    last_page = new_page;
-  }
-  return true;
-}
-
-
-bool SemiSpace::ShrinkTo(int new_capacity) {
-  ASSERT((new_capacity & Page::kPageAlignmentMask) == 0);
-  ASSERT(new_capacity >= initial_capacity_);
-  ASSERT(new_capacity < capacity_);
-  if (is_committed()) {
-    size_t delta = capacity_ - new_capacity;
-    ASSERT(IsAligned(delta, OS::AllocateAlignment()));
-
-    MemoryAllocator* allocator = heap()->isolate()->memory_allocator();
-    if (!allocator->UncommitBlock(start_ + new_capacity, delta)) {
-      return false;
-    }
-
-    int pages_after = new_capacity / Page::kPageSize;
-    NewSpacePage* new_last_page =
-        NewSpacePage::FromAddress(start_ + (pages_after - 1) * Page::kPageSize);
-    new_last_page->set_next_page(anchor());
-    anchor()->set_prev_page(new_last_page);
-    ASSERT((current_page_ >= first_page()) && (current_page_ <= new_last_page));
-  }
-
-  SetCapacity(new_capacity);
-
-  return true;
-}
-
-
-void SemiSpace::FlipPages(intptr_t flags, intptr_t mask) {
-  anchor_.set_owner(this);
-  // Fixup back-pointers to anchor. Address of anchor changes
-  // when we swap.
-  anchor_.prev_page()->set_next_page(&anchor_);
-  anchor_.next_page()->set_prev_page(&anchor_);
-
-  bool becomes_to_space = (id_ == kFromSpace);
-  id_ = becomes_to_space ? kToSpace : kFromSpace;
-  NewSpacePage* page = anchor_.next_page();
-  while (page != &anchor_) {
-    page->set_owner(this);
-    page->SetFlags(flags, mask);
-    if (becomes_to_space) {
-      page->ClearFlag(MemoryChunk::IN_FROM_SPACE);
-      page->SetFlag(MemoryChunk::IN_TO_SPACE);
-      page->ClearFlag(MemoryChunk::NEW_SPACE_BELOW_AGE_MARK);
-      page->ResetLiveBytes();
-    } else {
-      page->SetFlag(MemoryChunk::IN_FROM_SPACE);
-      page->ClearFlag(MemoryChunk::IN_TO_SPACE);
-    }
-    ASSERT(page->IsFlagSet(MemoryChunk::SCAN_ON_SCAVENGE));
-    ASSERT(page->IsFlagSet(MemoryChunk::IN_TO_SPACE) ||
-           page->IsFlagSet(MemoryChunk::IN_FROM_SPACE));
-    page = page->next_page();
-  }
-}
-
-
-void SemiSpace::Reset() {
-  ASSERT(anchor_.next_page() != &anchor_);
-  current_page_ = anchor_.next_page();
-}
-
-
-void SemiSpace::Swap(SemiSpace* from, SemiSpace* to) {
-  // We won't be swapping semispaces without data in them.
-  ASSERT(from->anchor_.next_page() != &from->anchor_);
-  ASSERT(to->anchor_.next_page() != &to->anchor_);
-
-  // Swap bits.
-  SemiSpace tmp = *from;
-  *from = *to;
-  *to = tmp;
-
-  // Fixup back-pointers to the page list anchor now that its address
-  // has changed.
-  // Swap to/from-space bits on pages.
-  // Copy GC flags from old active space (from-space) to new (to-space).
-  intptr_t flags = from->current_page()->GetFlags();
-  to->FlipPages(flags, NewSpacePage::kCopyOnFlipFlagsMask);
-
-  from->FlipPages(0, 0);
-}
-
-
-void SemiSpace::SetCapacity(int new_capacity) {
-  capacity_ = new_capacity;
-  if (capacity_ > maximum_committed_) {
-    maximum_committed_ = capacity_;
-  }
-}
-
-
-void SemiSpace::set_age_mark(Address mark) {
-  ASSERT(NewSpacePage::FromLimit(mark)->semi_space() == this);
-  age_mark_ = mark;
-  // Mark all pages up to the one containing mark.
-  NewSpacePageIterator it(space_start(), mark);
-  while (it.has_next()) {
-    it.next()->SetFlag(MemoryChunk::NEW_SPACE_BELOW_AGE_MARK);
-  }
-}
-
-
-#ifdef DEBUG
-void SemiSpace::Print() { }
-#endif
-
-#ifdef VERIFY_HEAP
-void SemiSpace::Verify() {
-  bool is_from_space = (id_ == kFromSpace);
-  NewSpacePage* page = anchor_.next_page();
-  CHECK(anchor_.semi_space() == this);
-  while (page != &anchor_) {
-    CHECK(page->semi_space() == this);
-    CHECK(page->InNewSpace());
-    CHECK(page->IsFlagSet(is_from_space ? MemoryChunk::IN_FROM_SPACE
-                                        : MemoryChunk::IN_TO_SPACE));
-    CHECK(!page->IsFlagSet(is_from_space ? MemoryChunk::IN_TO_SPACE
-                                         : MemoryChunk::IN_FROM_SPACE));
-    CHECK(page->IsFlagSet(MemoryChunk::POINTERS_TO_HERE_ARE_INTERESTING));
-    if (!is_from_space) {
-      // The pointers-from-here-are-interesting flag isn't updated dynamically
-      // on from-space pages, so it might be out of sync with the marking state.
-      if (page->heap()->incremental_marking()->IsMarking()) {
-        CHECK(page->IsFlagSet(MemoryChunk::POINTERS_FROM_HERE_ARE_INTERESTING));
-      } else {
-        CHECK(!page->IsFlagSet(
-            MemoryChunk::POINTERS_FROM_HERE_ARE_INTERESTING));
-      }
-      // TODO(gc): Check that the live_bytes_count_ field matches the
-      // black marking on the page (if we make it match in new-space).
-    }
-    CHECK(page->IsFlagSet(MemoryChunk::SCAN_ON_SCAVENGE));
-    CHECK(page->prev_page()->next_page() == page);
-    page = page->next_page();
-  }
-}
-#endif
-
-#ifdef DEBUG
-void SemiSpace::AssertValidRange(Address start, Address end) {
-  // Addresses belong to same semi-space
-  NewSpacePage* page = NewSpacePage::FromLimit(start);
-  NewSpacePage* end_page = NewSpacePage::FromLimit(end);
-  SemiSpace* space = page->semi_space();
-  CHECK_EQ(space, end_page->semi_space());
-  // Start address is before end address, either on same page,
-  // or end address is on a later page in the linked list of
-  // semi-space pages.
-  if (page == end_page) {
-    CHECK(start <= end);
-  } else {
-    while (page != end_page) {
-      page = page->next_page();
-      CHECK_NE(page, space->anchor());
-    }
-  }
-}
-#endif
-
-
-// -----------------------------------------------------------------------------
-// SemiSpaceIterator implementation.
-SemiSpaceIterator::SemiSpaceIterator(NewSpace* space) {
-  Initialize(space->bottom(), space->top(), NULL);
-}
-
-
-SemiSpaceIterator::SemiSpaceIterator(NewSpace* space,
-                                     HeapObjectCallback size_func) {
-  Initialize(space->bottom(), space->top(), size_func);
-}
-
-
-SemiSpaceIterator::SemiSpaceIterator(NewSpace* space, Address start) {
-  Initialize(start, space->top(), NULL);
-}
-
-
-SemiSpaceIterator::SemiSpaceIterator(Address from, Address to) {
-  Initialize(from, to, NULL);
-}
-
-
-void SemiSpaceIterator::Initialize(Address start,
-                                   Address end,
-                                   HeapObjectCallback size_func) {
-  SemiSpace::AssertValidRange(start, end);
-  current_ = start;
-  limit_ = end;
-  size_func_ = size_func;
-}
-
-
-#ifdef DEBUG
-// heap_histograms is shared, always clear it before using it.
-static void ClearHistograms(Isolate* isolate) {
-  // We reset the name each time, though it hasn't changed.
-#define DEF_TYPE_NAME(name) isolate->heap_histograms()[name].set_name(#name);
-  INSTANCE_TYPE_LIST(DEF_TYPE_NAME)
-#undef DEF_TYPE_NAME
-
-#define CLEAR_HISTOGRAM(name) isolate->heap_histograms()[name].clear();
-  INSTANCE_TYPE_LIST(CLEAR_HISTOGRAM)
-#undef CLEAR_HISTOGRAM
-
-  isolate->js_spill_information()->Clear();
-}
-
-
-static void ClearCodeKindStatistics(int* code_kind_statistics) {
-  for (int i = 0; i < Code::NUMBER_OF_KINDS; i++) {
-    code_kind_statistics[i] = 0;
-  }
-}
-
-
-static void ReportCodeKindStatistics(int* code_kind_statistics) {
-  PrintF("\n   Code kind histograms: \n");
-  for (int i = 0; i < Code::NUMBER_OF_KINDS; i++) {
-    if (code_kind_statistics[i] > 0) {
-      PrintF("     %-20s: %10d bytes\n",
-             Code::Kind2String(static_cast<Code::Kind>(i)),
-             code_kind_statistics[i]);
-    }
-  }
-  PrintF("\n");
-}
-
-
-static int CollectHistogramInfo(HeapObject* obj) {
-  Isolate* isolate = obj->GetIsolate();
-  InstanceType type = obj->map()->instance_type();
-  ASSERT(0 <= type && type <= LAST_TYPE);
-  ASSERT(isolate->heap_histograms()[type].name() != NULL);
-  isolate->heap_histograms()[type].increment_number(1);
-  isolate->heap_histograms()[type].increment_bytes(obj->Size());
-
-  if (FLAG_collect_heap_spill_statistics && obj->IsJSObject()) {
-    JSObject::cast(obj)->IncrementSpillStatistics(
-        isolate->js_spill_information());
-  }
-
-  return obj->Size();
-}
-
-
-static void ReportHistogram(Isolate* isolate, bool print_spill) {
-  PrintF("\n  Object Histogram:\n");
-  for (int i = 0; i <= LAST_TYPE; i++) {
-    if (isolate->heap_histograms()[i].number() > 0) {
-      PrintF("    %-34s%10d (%10d bytes)\n",
-             isolate->heap_histograms()[i].name(),
-             isolate->heap_histograms()[i].number(),
-             isolate->heap_histograms()[i].bytes());
-    }
-  }
-  PrintF("\n");
-
-  // Summarize string types.
-  int string_number = 0;
-  int string_bytes = 0;
-#define INCREMENT(type, size, name, camel_name)      \
-    string_number += isolate->heap_histograms()[type].number(); \
-    string_bytes += isolate->heap_histograms()[type].bytes();
-  STRING_TYPE_LIST(INCREMENT)
-#undef INCREMENT
-  if (string_number > 0) {
-    PrintF("    %-34s%10d (%10d bytes)\n\n", "STRING_TYPE", string_number,
-           string_bytes);
-  }
-
-  if (FLAG_collect_heap_spill_statistics && print_spill) {
-    isolate->js_spill_information()->Print();
-  }
-}
-#endif  // DEBUG
-
-
-// Support for statistics gathering for --heap-stats and --log-gc.
-void NewSpace::ClearHistograms() {
-  for (int i = 0; i <= LAST_TYPE; i++) {
-    allocated_histogram_[i].clear();
-    promoted_histogram_[i].clear();
-  }
-}
-
-
-// Because the copying collector does not touch garbage objects, we iterate
-// the new space before a collection to get a histogram of allocated objects.
-// This only happens when --log-gc flag is set.
-void NewSpace::CollectStatistics() {
-  ClearHistograms();
-  SemiSpaceIterator it(this);
-  for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next())
-    RecordAllocation(obj);
-}
-
-
-static void DoReportStatistics(Isolate* isolate,
-                               HistogramInfo* info, const char* description) {
-  LOG(isolate, HeapSampleBeginEvent("NewSpace", description));
-  // Lump all the string types together.
-  int string_number = 0;
-  int string_bytes = 0;
-#define INCREMENT(type, size, name, camel_name)       \
-    string_number += info[type].number();             \
-    string_bytes += info[type].bytes();
-  STRING_TYPE_LIST(INCREMENT)
-#undef INCREMENT
-  if (string_number > 0) {
-    LOG(isolate,
-        HeapSampleItemEvent("STRING_TYPE", string_number, string_bytes));
-  }
-
-  // Then do the other types.
-  for (int i = FIRST_NONSTRING_TYPE; i <= LAST_TYPE; ++i) {
-    if (info[i].number() > 0) {
-      LOG(isolate,
-          HeapSampleItemEvent(info[i].name(), info[i].number(),
-                              info[i].bytes()));
-    }
-  }
-  LOG(isolate, HeapSampleEndEvent("NewSpace", description));
-}
-
-
-void NewSpace::ReportStatistics() {
-#ifdef DEBUG
-  if (FLAG_heap_stats) {
-    float pct = static_cast<float>(Available()) / Capacity();
-    PrintF("  capacity: %" V8_PTR_PREFIX "d"
-               ", available: %" V8_PTR_PREFIX "d, %%%d\n",
-           Capacity(), Available(), static_cast<int>(pct*100));
-    PrintF("\n  Object Histogram:\n");
-    for (int i = 0; i <= LAST_TYPE; i++) {
-      if (allocated_histogram_[i].number() > 0) {
-        PrintF("    %-34s%10d (%10d bytes)\n",
-               allocated_histogram_[i].name(),
-               allocated_histogram_[i].number(),
-               allocated_histogram_[i].bytes());
-      }
-    }
-    PrintF("\n");
-  }
-#endif  // DEBUG
-
-  if (FLAG_log_gc) {
-    Isolate* isolate = heap()->isolate();
-    DoReportStatistics(isolate, allocated_histogram_, "allocated");
-    DoReportStatistics(isolate, promoted_histogram_, "promoted");
-  }
-}
-
-
-void NewSpace::RecordAllocation(HeapObject* obj) {
-  InstanceType type = obj->map()->instance_type();
-  ASSERT(0 <= type && type <= LAST_TYPE);
-  allocated_histogram_[type].increment_number(1);
-  allocated_histogram_[type].increment_bytes(obj->Size());
-}
-
-
-void NewSpace::RecordPromotion(HeapObject* obj) {
-  InstanceType type = obj->map()->instance_type();
-  ASSERT(0 <= type && type <= LAST_TYPE);
-  promoted_histogram_[type].increment_number(1);
-  promoted_histogram_[type].increment_bytes(obj->Size());
-}
-
-
-size_t NewSpace::CommittedPhysicalMemory() {
-  if (!VirtualMemory::HasLazyCommits()) return CommittedMemory();
-  MemoryChunk::UpdateHighWaterMark(allocation_info_.top());
-  size_t size = to_space_.CommittedPhysicalMemory();
-  if (from_space_.is_committed()) {
-    size += from_space_.CommittedPhysicalMemory();
-  }
-  return size;
-}
-
-
-// -----------------------------------------------------------------------------
-// Free lists for old object spaces implementation
-
-void FreeListNode::set_size(Heap* heap, int size_in_bytes) {
-  ASSERT(size_in_bytes > 0);
-  ASSERT(IsAligned(size_in_bytes, kPointerSize));
-
-  // We write a map and possibly size information to the block.  If the block
-  // is big enough to be a FreeSpace with at least one extra word (the next
-  // pointer), we set its map to be the free space map and its size to an
-  // appropriate array length for the desired size from HeapObject::Size().
-  // If the block is too small (eg, one or two words), to hold both a size
-  // field and a next pointer, we give it a filler map that gives it the
-  // correct size.
-  if (size_in_bytes > FreeSpace::kHeaderSize) {
-    // Can't use FreeSpace::cast because it fails during deserialization.
-    // We have to set the size first with a release store before we store
-    // the map because a concurrent store buffer scan on scavenge must not
-    // observe a map with an invalid size.
-    FreeSpace* this_as_free_space = reinterpret_cast<FreeSpace*>(this);
-    this_as_free_space->nobarrier_set_size(size_in_bytes);
-    synchronized_set_map_no_write_barrier(heap->raw_unchecked_free_space_map());
-  } else if (size_in_bytes == kPointerSize) {
-    set_map_no_write_barrier(heap->raw_unchecked_one_pointer_filler_map());
-  } else if (size_in_bytes == 2 * kPointerSize) {
-    set_map_no_write_barrier(heap->raw_unchecked_two_pointer_filler_map());
-  } else {
-    UNREACHABLE();
-  }
-  // We would like to ASSERT(Size() == size_in_bytes) but this would fail during
-  // deserialization because the free space map is not done yet.
-}
-
-
-FreeListNode* FreeListNode::next() {
-  ASSERT(IsFreeListNode(this));
-  if (map() == GetHeap()->raw_unchecked_free_space_map()) {
-    ASSERT(map() == NULL || Size() >= kNextOffset + kPointerSize);
-    return reinterpret_cast<FreeListNode*>(
-        Memory::Address_at(address() + kNextOffset));
-  } else {
-    return reinterpret_cast<FreeListNode*>(
-        Memory::Address_at(address() + kPointerSize));
-  }
-}
-
-
-FreeListNode** FreeListNode::next_address() {
-  ASSERT(IsFreeListNode(this));
-  if (map() == GetHeap()->raw_unchecked_free_space_map()) {
-    ASSERT(Size() >= kNextOffset + kPointerSize);
-    return reinterpret_cast<FreeListNode**>(address() + kNextOffset);
-  } else {
-    return reinterpret_cast<FreeListNode**>(address() + kPointerSize);
-  }
-}
-
-
-void FreeListNode::set_next(FreeListNode* next) {
-  ASSERT(IsFreeListNode(this));
-  // While we are booting the VM the free space map will actually be null.  So
-  // we have to make sure that we don't try to use it for anything at that
-  // stage.
-  if (map() == GetHeap()->raw_unchecked_free_space_map()) {
-    ASSERT(map() == NULL || Size() >= kNextOffset + kPointerSize);
-    NoBarrier_Store(reinterpret_cast<AtomicWord*>(address() + kNextOffset),
-                    reinterpret_cast<AtomicWord>(next));
-  } else {
-    NoBarrier_Store(reinterpret_cast<AtomicWord*>(address() + kPointerSize),
-                    reinterpret_cast<AtomicWord>(next));
-  }
-}
-
-
-intptr_t FreeListCategory::Concatenate(FreeListCategory* category) {
-  intptr_t free_bytes = 0;
-  if (category->top() != NULL) {
-    // This is safe (not going to deadlock) since Concatenate operations
-    // are never performed on the same free lists at the same time in
-    // reverse order.
-    LockGuard<Mutex> target_lock_guard(mutex());
-    LockGuard<Mutex> source_lock_guard(category->mutex());
-    ASSERT(category->end_ != NULL);
-    free_bytes = category->available();
-    if (end_ == NULL) {
-      end_ = category->end();
-    } else {
-      category->end()->set_next(top());
-    }
-    set_top(category->top());
-    NoBarrier_Store(&top_, category->top_);
-    available_ += category->available();
-    category->Reset();
-  }
-  return free_bytes;
-}
-
-
-void FreeListCategory::Reset() {
-  set_top(NULL);
-  set_end(NULL);
-  set_available(0);
-}
-
-
-intptr_t FreeListCategory::EvictFreeListItemsInList(Page* p) {
-  int sum = 0;
-  FreeListNode* t = top();
-  FreeListNode** n = &t;
-  while (*n != NULL) {
-    if (Page::FromAddress((*n)->address()) == p) {
-      FreeSpace* free_space = reinterpret_cast<FreeSpace*>(*n);
-      sum += free_space->Size();
-      *n = (*n)->next();
-    } else {
-      n = (*n)->next_address();
-    }
-  }
-  set_top(t);
-  if (top() == NULL) {
-    set_end(NULL);
-  }
-  available_ -= sum;
-  return sum;
-}
-
-
-bool FreeListCategory::ContainsPageFreeListItemsInList(Page* p) {
-  FreeListNode* node = top();
-  while (node != NULL) {
-    if (Page::FromAddress(node->address()) == p) return true;
-    node = node->next();
-  }
-  return false;
-}
-
-
-FreeListNode* FreeListCategory::PickNodeFromList(int *node_size) {
-  FreeListNode* node = top();
-
-  if (node == NULL) return NULL;
-
-  while (node != NULL &&
-         Page::FromAddress(node->address())->IsEvacuationCandidate()) {
-    available_ -= reinterpret_cast<FreeSpace*>(node)->Size();
-    node = node->next();
-  }
-
-  if (node != NULL) {
-    set_top(node->next());
-    *node_size = reinterpret_cast<FreeSpace*>(node)->Size();
-    available_ -= *node_size;
-  } else {
-    set_top(NULL);
-  }
-
-  if (top() == NULL) {
-    set_end(NULL);
-  }
-
-  return node;
-}
-
-
-FreeListNode* FreeListCategory::PickNodeFromList(int size_in_bytes,
-                                                 int *node_size) {
-  FreeListNode* node = PickNodeFromList(node_size);
-  if (node != NULL && *node_size < size_in_bytes) {
-    Free(node, *node_size);
-    *node_size = 0;
-    return NULL;
-  }
-  return node;
-}
-
-
-void FreeListCategory::Free(FreeListNode* node, int size_in_bytes) {
-  node->set_next(top());
-  set_top(node);
-  if (end_ == NULL) {
-    end_ = node;
-  }
-  available_ += size_in_bytes;
-}
-
-
-void FreeListCategory::RepairFreeList(Heap* heap) {
-  FreeListNode* n = top();
-  while (n != NULL) {
-    Map** map_location = reinterpret_cast<Map**>(n->address());
-    if (*map_location == NULL) {
-      *map_location = heap->free_space_map();
-    } else {
-      ASSERT(*map_location == heap->free_space_map());
-    }
-    n = n->next();
-  }
-}
-
-
-FreeList::FreeList(PagedSpace* owner)
-    : owner_(owner), heap_(owner->heap()) {
-  Reset();
-}
-
-
-intptr_t FreeList::Concatenate(FreeList* free_list) {
-  intptr_t free_bytes = 0;
-  free_bytes += small_list_.Concatenate(free_list->small_list());
-  free_bytes += medium_list_.Concatenate(free_list->medium_list());
-  free_bytes += large_list_.Concatenate(free_list->large_list());
-  free_bytes += huge_list_.Concatenate(free_list->huge_list());
-  return free_bytes;
-}
-
-
-void FreeList::Reset() {
-  small_list_.Reset();
-  medium_list_.Reset();
-  large_list_.Reset();
-  huge_list_.Reset();
-}
-
-
-int FreeList::Free(Address start, int size_in_bytes) {
-  if (size_in_bytes == 0) return 0;
-
-  FreeListNode* node = FreeListNode::FromAddress(start);
-  node->set_size(heap_, size_in_bytes);
-  Page* page = Page::FromAddress(start);
-
-  // Early return to drop too-small blocks on the floor.
-  if (size_in_bytes < kSmallListMin) {
-    page->add_non_available_small_blocks(size_in_bytes);
-    return size_in_bytes;
-  }
-
-  // Insert other blocks at the head of a free list of the appropriate
-  // magnitude.
-  if (size_in_bytes <= kSmallListMax) {
-    small_list_.Free(node, size_in_bytes);
-    page->add_available_in_small_free_list(size_in_bytes);
-  } else if (size_in_bytes <= kMediumListMax) {
-    medium_list_.Free(node, size_in_bytes);
-    page->add_available_in_medium_free_list(size_in_bytes);
-  } else if (size_in_bytes <= kLargeListMax) {
-    large_list_.Free(node, size_in_bytes);
-    page->add_available_in_large_free_list(size_in_bytes);
-  } else {
-    huge_list_.Free(node, size_in_bytes);
-    page->add_available_in_huge_free_list(size_in_bytes);
-  }
-
-  ASSERT(IsVeryLong() || available() == SumFreeLists());
-  return 0;
-}
-
-
-FreeListNode* FreeList::FindNodeFor(int size_in_bytes, int* node_size) {
-  FreeListNode* node = NULL;
-  Page* page = NULL;
-
-  if (size_in_bytes <= kSmallAllocationMax) {
-    node = small_list_.PickNodeFromList(node_size);
-    if (node != NULL) {
-      ASSERT(size_in_bytes <= *node_size);
-      page = Page::FromAddress(node->address());
-      page->add_available_in_small_free_list(-(*node_size));
-      ASSERT(IsVeryLong() || available() == SumFreeLists());
-      return node;
-    }
-  }
-
-  if (size_in_bytes <= kMediumAllocationMax) {
-    node = medium_list_.PickNodeFromList(node_size);
-    if (node != NULL) {
-      ASSERT(size_in_bytes <= *node_size);
-      page = Page::FromAddress(node->address());
-      page->add_available_in_medium_free_list(-(*node_size));
-      ASSERT(IsVeryLong() || available() == SumFreeLists());
-      return node;
-    }
-  }
-
-  if (size_in_bytes <= kLargeAllocationMax) {
-    node = large_list_.PickNodeFromList(node_size);
-    if (node != NULL) {
-      ASSERT(size_in_bytes <= *node_size);
-      page = Page::FromAddress(node->address());
-      page->add_available_in_large_free_list(-(*node_size));
-      ASSERT(IsVeryLong() || available() == SumFreeLists());
-      return node;
-    }
-  }
-
-  int huge_list_available = huge_list_.available();
-  FreeListNode* top_node = huge_list_.top();
-  for (FreeListNode** cur = &top_node;
-       *cur != NULL;
-       cur = (*cur)->next_address()) {
-    FreeListNode* cur_node = *cur;
-    while (cur_node != NULL &&
-           Page::FromAddress(cur_node->address())->IsEvacuationCandidate()) {
-      int size = reinterpret_cast<FreeSpace*>(cur_node)->Size();
-      huge_list_available -= size;
-      page = Page::FromAddress(cur_node->address());
-      page->add_available_in_huge_free_list(-size);
-      cur_node = cur_node->next();
-    }
-
-    *cur = cur_node;
-    if (cur_node == NULL) {
-      huge_list_.set_end(NULL);
-      break;
-    }
-
-    ASSERT((*cur)->map() == heap_->raw_unchecked_free_space_map());
-    FreeSpace* cur_as_free_space = reinterpret_cast<FreeSpace*>(*cur);
-    int size = cur_as_free_space->Size();
-    if (size >= size_in_bytes) {
-      // Large enough node found.  Unlink it from the list.
-      node = *cur;
-      *cur = node->next();
-      *node_size = size;
-      huge_list_available -= size;
-      page = Page::FromAddress(node->address());
-      page->add_available_in_huge_free_list(-size);
-      break;
-    }
-  }
-
-  huge_list_.set_top(top_node);
-  if (huge_list_.top() == NULL) {
-    huge_list_.set_end(NULL);
-  }
-  huge_list_.set_available(huge_list_available);
-
-  if (node != NULL) {
-    ASSERT(IsVeryLong() || available() == SumFreeLists());
-    return node;
-  }
-
-  if (size_in_bytes <= kSmallListMax) {
-    node = small_list_.PickNodeFromList(size_in_bytes, node_size);
-    if (node != NULL) {
-      ASSERT(size_in_bytes <= *node_size);
-      page = Page::FromAddress(node->address());
-      page->add_available_in_small_free_list(-(*node_size));
-    }
-  } else if (size_in_bytes <= kMediumListMax) {
-    node = medium_list_.PickNodeFromList(size_in_bytes, node_size);
-    if (node != NULL) {
-      ASSERT(size_in_bytes <= *node_size);
-      page = Page::FromAddress(node->address());
-      page->add_available_in_medium_free_list(-(*node_size));
-    }
-  } else if (size_in_bytes <= kLargeListMax) {
-    node = large_list_.PickNodeFromList(size_in_bytes, node_size);
-    if (node != NULL) {
-      ASSERT(size_in_bytes <= *node_size);
-      page = Page::FromAddress(node->address());
-      page->add_available_in_large_free_list(-(*node_size));
-    }
-  }
-
-  ASSERT(IsVeryLong() || available() == SumFreeLists());
-  return node;
-}
-
-
-// Allocation on the old space free list.  If it succeeds then a new linear
-// allocation space has been set up with the top and limit of the space.  If
-// the allocation fails then NULL is returned, and the caller can perform a GC
-// or allocate a new page before retrying.
-HeapObject* FreeList::Allocate(int size_in_bytes) {
-  ASSERT(0 < size_in_bytes);
-  ASSERT(size_in_bytes <= kMaxBlockSize);
-  ASSERT(IsAligned(size_in_bytes, kPointerSize));
-  // Don't free list allocate if there is linear space available.
-  ASSERT(owner_->limit() - owner_->top() < size_in_bytes);
-
-  int old_linear_size = static_cast<int>(owner_->limit() - owner_->top());
-  // Mark the old linear allocation area with a free space map so it can be
-  // skipped when scanning the heap.  This also puts it back in the free list
-  // if it is big enough.
-  owner_->Free(owner_->top(), old_linear_size);
-
-  owner_->heap()->incremental_marking()->OldSpaceStep(
-      size_in_bytes - old_linear_size);
-
-  int new_node_size = 0;
-  FreeListNode* new_node = FindNodeFor(size_in_bytes, &new_node_size);
-  if (new_node == NULL) {
-    owner_->SetTopAndLimit(NULL, NULL);
-    return NULL;
-  }
-
-  int bytes_left = new_node_size - size_in_bytes;
-  ASSERT(bytes_left >= 0);
-
-#ifdef DEBUG
-  for (int i = 0; i < size_in_bytes / kPointerSize; i++) {
-    reinterpret_cast<Object**>(new_node->address())[i] =
-        Smi::FromInt(kCodeZapValue);
-  }
-#endif
-
-  // The old-space-step might have finished sweeping and restarted marking.
-  // Verify that it did not turn the page of the new node into an evacuation
-  // candidate.
-  ASSERT(!MarkCompactCollector::IsOnEvacuationCandidate(new_node));
-
-  const int kThreshold = IncrementalMarking::kAllocatedThreshold;
-
-  // Memory in the linear allocation area is counted as allocated.  We may free
-  // a little of this again immediately - see below.
-  owner_->Allocate(new_node_size);
-
-  if (owner_->heap()->inline_allocation_disabled()) {
-    // Keep the linear allocation area empty if requested to do so, just
-    // return area back to the free list instead.
-    owner_->Free(new_node->address() + size_in_bytes, bytes_left);
-    ASSERT(owner_->top() == NULL && owner_->limit() == NULL);
-  } else if (bytes_left > kThreshold &&
-             owner_->heap()->incremental_marking()->IsMarkingIncomplete() &&
-             FLAG_incremental_marking_steps) {
-    int linear_size = owner_->RoundSizeDownToObjectAlignment(kThreshold);
-    // We don't want to give too large linear areas to the allocator while
-    // incremental marking is going on, because we won't check again whether
-    // we want to do another increment until the linear area is used up.
-    owner_->Free(new_node->address() + size_in_bytes + linear_size,
-                 new_node_size - size_in_bytes - linear_size);
-    owner_->SetTopAndLimit(new_node->address() + size_in_bytes,
-                           new_node->address() + size_in_bytes + linear_size);
-  } else if (bytes_left > 0) {
-    // Normally we give the rest of the node to the allocator as its new
-    // linear allocation area.
-    owner_->SetTopAndLimit(new_node->address() + size_in_bytes,
-                           new_node->address() + new_node_size);
-  } else {
-    // TODO(gc) Try not freeing linear allocation region when bytes_left
-    // are zero.
-    owner_->SetTopAndLimit(NULL, NULL);
-  }
-
-  return new_node;
-}
-
-
-intptr_t FreeList::EvictFreeListItems(Page* p) {
-  intptr_t sum = huge_list_.EvictFreeListItemsInList(p);
-  p->set_available_in_huge_free_list(0);
-
-  if (sum < p->area_size()) {
-    sum += small_list_.EvictFreeListItemsInList(p) +
-        medium_list_.EvictFreeListItemsInList(p) +
-        large_list_.EvictFreeListItemsInList(p);
-    p->set_available_in_small_free_list(0);
-    p->set_available_in_medium_free_list(0);
-    p->set_available_in_large_free_list(0);
-  }
-
-  return sum;
-}
-
-
-bool FreeList::ContainsPageFreeListItems(Page* p) {
-  return huge_list_.EvictFreeListItemsInList(p) ||
-         small_list_.EvictFreeListItemsInList(p) ||
-         medium_list_.EvictFreeListItemsInList(p) ||
-         large_list_.EvictFreeListItemsInList(p);
-}
-
-
-void FreeList::RepairLists(Heap* heap) {
-  small_list_.RepairFreeList(heap);
-  medium_list_.RepairFreeList(heap);
-  large_list_.RepairFreeList(heap);
-  huge_list_.RepairFreeList(heap);
-}
-
-
-#ifdef DEBUG
-intptr_t FreeListCategory::SumFreeList() {
-  intptr_t sum = 0;
-  FreeListNode* cur = top();
-  while (cur != NULL) {
-    ASSERT(cur->map() == cur->GetHeap()->raw_unchecked_free_space_map());
-    FreeSpace* cur_as_free_space = reinterpret_cast<FreeSpace*>(cur);
-    sum += cur_as_free_space->nobarrier_size();
-    cur = cur->next();
-  }
-  return sum;
-}
-
-
-static const int kVeryLongFreeList = 500;
-
-
-int FreeListCategory::FreeListLength() {
-  int length = 0;
-  FreeListNode* cur = top();
-  while (cur != NULL) {
-    length++;
-    cur = cur->next();
-    if (length == kVeryLongFreeList) return length;
-  }
-  return length;
-}
-
-
-bool FreeList::IsVeryLong() {
-  if (small_list_.FreeListLength() == kVeryLongFreeList) return  true;
-  if (medium_list_.FreeListLength() == kVeryLongFreeList) return  true;
-  if (large_list_.FreeListLength() == kVeryLongFreeList) return  true;
-  if (huge_list_.FreeListLength() == kVeryLongFreeList) return  true;
-  return false;
-}
-
-
-// This can take a very long time because it is linear in the number of entries
-// on the free list, so it should not be called if FreeListLength returns
-// kVeryLongFreeList.
-intptr_t FreeList::SumFreeLists() {
-  intptr_t sum = small_list_.SumFreeList();
-  sum += medium_list_.SumFreeList();
-  sum += large_list_.SumFreeList();
-  sum += huge_list_.SumFreeList();
-  return sum;
-}
-#endif
-
-
-// -----------------------------------------------------------------------------
-// OldSpace implementation
-
-void PagedSpace::PrepareForMarkCompact() {
-  // We don't have a linear allocation area while sweeping.  It will be restored
-  // on the first allocation after the sweep.
-  EmptyAllocationInfo();
-
-  // This counter will be increased for pages which will be swept by the
-  // sweeper threads.
-  unswept_free_bytes_ = 0;
-
-  // Clear the free list before a full GC---it will be rebuilt afterward.
-  free_list_.Reset();
-}
-
-
-intptr_t PagedSpace::SizeOfObjects() {
-  ASSERT(heap()->mark_compact_collector()->IsConcurrentSweepingInProgress() ||
-         (unswept_free_bytes_ == 0));
-  return Size() - unswept_free_bytes_ - (limit() - top());
-}
-
-
-// After we have booted, we have created a map which represents free space
-// on the heap.  If there was already a free list then the elements on it
-// were created with the wrong FreeSpaceMap (normally NULL), so we need to
-// fix them.
-void PagedSpace::RepairFreeListsAfterBoot() {
-  free_list_.RepairLists(heap());
-}
-
-
-void PagedSpace::EvictEvacuationCandidatesFromFreeLists() {
-  if (allocation_info_.top() >= allocation_info_.limit()) return;
-
-  if (Page::FromAllocationTop(allocation_info_.top())->
-      IsEvacuationCandidate()) {
-    // Create filler object to keep page iterable if it was iterable.
-    int remaining =
-        static_cast<int>(allocation_info_.limit() - allocation_info_.top());
-    heap()->CreateFillerObjectAt(allocation_info_.top(), remaining);
-
-    allocation_info_.set_top(NULL);
-    allocation_info_.set_limit(NULL);
-  }
-}
-
-
-HeapObject* PagedSpace::SlowAllocateRaw(int size_in_bytes) {
-  // Allocation in this space has failed.
-
-  // If sweeper threads are active, try to re-fill the free-lists.
-  MarkCompactCollector* collector = heap()->mark_compact_collector();
-  if (collector->IsConcurrentSweepingInProgress()) {
-    collector->RefillFreeList(this);
-
-    // Retry the free list allocation.
-    HeapObject* object = free_list_.Allocate(size_in_bytes);
-    if (object != NULL) return object;
-  }
-
-  // Free list allocation failed and there is no next page.  Fail if we have
-  // hit the old generation size limit that should cause a garbage
-  // collection.
-  if (!heap()->always_allocate() &&
-      heap()->OldGenerationAllocationLimitReached()) {
-    return NULL;
-  }
-
-  // Try to expand the space and allocate in the new next page.
-  if (Expand()) {
-    ASSERT(CountTotalPages() > 1 || size_in_bytes <= free_list_.available());
-    return free_list_.Allocate(size_in_bytes);
-  }
-
-  // If sweeper threads are active, wait for them at that point.
-  if (collector->IsConcurrentSweepingInProgress()) {
-    collector->WaitUntilSweepingCompleted();
-
-    // After waiting for the sweeper threads, there may be new free-list
-    // entries.
-    HeapObject* object = free_list_.Allocate(size_in_bytes);
-    if (object != NULL) return object;
-  }
-
-  // Finally, fail.
-  return NULL;
-}
-
-
-#ifdef DEBUG
-void PagedSpace::ReportCodeStatistics(Isolate* isolate) {
-  CommentStatistic* comments_statistics =
-      isolate->paged_space_comments_statistics();
-  ReportCodeKindStatistics(isolate->code_kind_statistics());
-  PrintF("Code comment statistics (\"   [ comment-txt   :    size/   "
-         "count  (average)\"):\n");
-  for (int i = 0; i <= CommentStatistic::kMaxComments; i++) {
-    const CommentStatistic& cs = comments_statistics[i];
-    if (cs.size > 0) {
-      PrintF("   %-30s: %10d/%6d     (%d)\n", cs.comment, cs.size, cs.count,
-             cs.size/cs.count);
-    }
-  }
-  PrintF("\n");
-}
-
-
-void PagedSpace::ResetCodeStatistics(Isolate* isolate) {
-  CommentStatistic* comments_statistics =
-      isolate->paged_space_comments_statistics();
-  ClearCodeKindStatistics(isolate->code_kind_statistics());
-  for (int i = 0; i < CommentStatistic::kMaxComments; i++) {
-    comments_statistics[i].Clear();
-  }
-  comments_statistics[CommentStatistic::kMaxComments].comment = "Unknown";
-  comments_statistics[CommentStatistic::kMaxComments].size = 0;
-  comments_statistics[CommentStatistic::kMaxComments].count = 0;
-}
-
-
-// Adds comment to 'comment_statistics' table. Performance OK as long as
-// 'kMaxComments' is small
-static void EnterComment(Isolate* isolate, const char* comment, int delta) {
-  CommentStatistic* comments_statistics =
-      isolate->paged_space_comments_statistics();
-  // Do not count empty comments
-  if (delta <= 0) return;
-  CommentStatistic* cs = &comments_statistics[CommentStatistic::kMaxComments];
-  // Search for a free or matching entry in 'comments_statistics': 'cs'
-  // points to result.
-  for (int i = 0; i < CommentStatistic::kMaxComments; i++) {
-    if (comments_statistics[i].comment == NULL) {
-      cs = &comments_statistics[i];
-      cs->comment = comment;
-      break;
-    } else if (strcmp(comments_statistics[i].comment, comment) == 0) {
-      cs = &comments_statistics[i];
-      break;
-    }
-  }
-  // Update entry for 'comment'
-  cs->size += delta;
-  cs->count += 1;
-}
-
-
-// Call for each nested comment start (start marked with '[ xxx', end marked
-// with ']'.  RelocIterator 'it' must point to a comment reloc info.
-static void CollectCommentStatistics(Isolate* isolate, RelocIterator* it) {
-  ASSERT(!it->done());
-  ASSERT(it->rinfo()->rmode() == RelocInfo::COMMENT);
-  const char* tmp = reinterpret_cast<const char*>(it->rinfo()->data());
-  if (tmp[0] != '[') {
-    // Not a nested comment; skip
-    return;
-  }
-
-  // Search for end of nested comment or a new nested comment
-  const char* const comment_txt =
-      reinterpret_cast<const char*>(it->rinfo()->data());
-  const byte* prev_pc = it->rinfo()->pc();
-  int flat_delta = 0;
-  it->next();
-  while (true) {
-    // All nested comments must be terminated properly, and therefore exit
-    // from loop.
-    ASSERT(!it->done());
-    if (it->rinfo()->rmode() == RelocInfo::COMMENT) {
-      const char* const txt =
-          reinterpret_cast<const char*>(it->rinfo()->data());
-      flat_delta += static_cast<int>(it->rinfo()->pc() - prev_pc);
-      if (txt[0] == ']') break;  // End of nested  comment
-      // A new comment
-      CollectCommentStatistics(isolate, it);
-      // Skip code that was covered with previous comment
-      prev_pc = it->rinfo()->pc();
-    }
-    it->next();
-  }
-  EnterComment(isolate, comment_txt, flat_delta);
-}
-
-
-// Collects code size statistics:
-// - by code kind
-// - by code comment
-void PagedSpace::CollectCodeStatistics() {
-  Isolate* isolate = heap()->isolate();
-  HeapObjectIterator obj_it(this);
-  for (HeapObject* obj = obj_it.Next(); obj != NULL; obj = obj_it.Next()) {
-    if (obj->IsCode()) {
-      Code* code = Code::cast(obj);
-      isolate->code_kind_statistics()[code->kind()] += code->Size();
-      RelocIterator it(code);
-      int delta = 0;
-      const byte* prev_pc = code->instruction_start();
-      while (!it.done()) {
-        if (it.rinfo()->rmode() == RelocInfo::COMMENT) {
-          delta += static_cast<int>(it.rinfo()->pc() - prev_pc);
-          CollectCommentStatistics(isolate, &it);
-          prev_pc = it.rinfo()->pc();
-        }
-        it.next();
-      }
-
-      ASSERT(code->instruction_start() <= prev_pc &&
-             prev_pc <= code->instruction_end());
-      delta += static_cast<int>(code->instruction_end() - prev_pc);
-      EnterComment(isolate, "NoComment", delta);
-    }
-  }
-}
-
-
-void PagedSpace::ReportStatistics() {
-  int pct = static_cast<int>(Available() * 100 / Capacity());
-  PrintF("  capacity: %" V8_PTR_PREFIX "d"
-             ", waste: %" V8_PTR_PREFIX "d"
-             ", available: %" V8_PTR_PREFIX "d, %%%d\n",
-         Capacity(), Waste(), Available(), pct);
-
-  if (was_swept_conservatively_) return;
-  ClearHistograms(heap()->isolate());
-  HeapObjectIterator obj_it(this);
-  for (HeapObject* obj = obj_it.Next(); obj != NULL; obj = obj_it.Next())
-    CollectHistogramInfo(obj);
-  ReportHistogram(heap()->isolate(), true);
-}
-#endif
-
-
-// -----------------------------------------------------------------------------
-// MapSpace implementation
-// TODO(mvstanton): this is weird...the compiler can't make a vtable unless
-// there is at least one non-inlined virtual function. I would prefer to hide
-// the VerifyObject definition behind VERIFY_HEAP.
-
-void MapSpace::VerifyObject(HeapObject* object) {
-  CHECK(object->IsMap());
-}
-
-
-// -----------------------------------------------------------------------------
-// CellSpace and PropertyCellSpace implementation
-// TODO(mvstanton): this is weird...the compiler can't make a vtable unless
-// there is at least one non-inlined virtual function. I would prefer to hide
-// the VerifyObject definition behind VERIFY_HEAP.
-
-void CellSpace::VerifyObject(HeapObject* object) {
-  CHECK(object->IsCell());
-}
-
-
-void PropertyCellSpace::VerifyObject(HeapObject* object) {
-  CHECK(object->IsPropertyCell());
-}
-
-
-// -----------------------------------------------------------------------------
-// LargeObjectIterator
-
-LargeObjectIterator::LargeObjectIterator(LargeObjectSpace* space) {
-  current_ = space->first_page_;
-  size_func_ = NULL;
-}
-
-
-LargeObjectIterator::LargeObjectIterator(LargeObjectSpace* space,
-                                         HeapObjectCallback size_func) {
-  current_ = space->first_page_;
-  size_func_ = size_func;
-}
-
-
-HeapObject* LargeObjectIterator::Next() {
-  if (current_ == NULL) return NULL;
-
-  HeapObject* object = current_->GetObject();
-  current_ = current_->next_page();
-  return object;
-}
-
-
-// -----------------------------------------------------------------------------
-// LargeObjectSpace
-static bool ComparePointers(void* key1, void* key2) {
-    return key1 == key2;
-}
-
-
-LargeObjectSpace::LargeObjectSpace(Heap* heap,
-                                   intptr_t max_capacity,
-                                   AllocationSpace id)
-    : Space(heap, id, NOT_EXECUTABLE),  // Managed on a per-allocation basis
-      max_capacity_(max_capacity),
-      first_page_(NULL),
-      size_(0),
-      page_count_(0),
-      objects_size_(0),
-      chunk_map_(ComparePointers, 1024) {}
-
-
-bool LargeObjectSpace::SetUp() {
-  first_page_ = NULL;
-  size_ = 0;
-  maximum_committed_ = 0;
-  page_count_ = 0;
-  objects_size_ = 0;
-  chunk_map_.Clear();
-  return true;
-}
-
-
-void LargeObjectSpace::TearDown() {
-  while (first_page_ != NULL) {
-    LargePage* page = first_page_;
-    first_page_ = first_page_->next_page();
-    LOG(heap()->isolate(), DeleteEvent("LargeObjectChunk", page->address()));
-
-    ObjectSpace space = static_cast<ObjectSpace>(1 << identity());
-    heap()->isolate()->memory_allocator()->PerformAllocationCallback(
-        space, kAllocationActionFree, page->size());
-    heap()->isolate()->memory_allocator()->Free(page);
-  }
-  SetUp();
-}
-
-
-AllocationResult LargeObjectSpace::AllocateRaw(int object_size,
-                                               Executability executable) {
-  // Check if we want to force a GC before growing the old space further.
-  // If so, fail the allocation.
-  if (!heap()->always_allocate() &&
-      heap()->OldGenerationAllocationLimitReached()) {
-    return AllocationResult::Retry(identity());
-  }
-
-  if (Size() + object_size > max_capacity_) {
-    return AllocationResult::Retry(identity());
-  }
-
-  LargePage* page = heap()->isolate()->memory_allocator()->
-      AllocateLargePage(object_size, this, executable);
-  if (page == NULL) return AllocationResult::Retry(identity());
-  ASSERT(page->area_size() >= object_size);
-
-  size_ += static_cast<int>(page->size());
-  objects_size_ += object_size;
-  page_count_++;
-  page->set_next_page(first_page_);
-  first_page_ = page;
-
-  if (size_ > maximum_committed_) {
-    maximum_committed_ = size_;
-  }
-
-  // Register all MemoryChunk::kAlignment-aligned chunks covered by
-  // this large page in the chunk map.
-  uintptr_t base = reinterpret_cast<uintptr_t>(page) / MemoryChunk::kAlignment;
-  uintptr_t limit = base + (page->size() - 1) / MemoryChunk::kAlignment;
-  for (uintptr_t key = base; key <= limit; key++) {
-    HashMap::Entry* entry = chunk_map_.Lookup(reinterpret_cast<void*>(key),
-                                              static_cast<uint32_t>(key),
-                                              true);
-    ASSERT(entry != NULL);
-    entry->value = page;
-  }
-
-  HeapObject* object = page->GetObject();
-
-  if (Heap::ShouldZapGarbage()) {
-    // Make the object consistent so the heap can be verified in OldSpaceStep.
-    // We only need to do this in debug builds or if verify_heap is on.
-    reinterpret_cast<Object**>(object->address())[0] =
-        heap()->fixed_array_map();
-    reinterpret_cast<Object**>(object->address())[1] = Smi::FromInt(0);
-  }
-
-  heap()->incremental_marking()->OldSpaceStep(object_size);
-  return object;
-}
-
-
-size_t LargeObjectSpace::CommittedPhysicalMemory() {
-  if (!VirtualMemory::HasLazyCommits()) return CommittedMemory();
-  size_t size = 0;
-  LargePage* current = first_page_;
-  while (current != NULL) {
-    size += current->CommittedPhysicalMemory();
-    current = current->next_page();
-  }
-  return size;
-}
-
-
-// GC support
-Object* LargeObjectSpace::FindObject(Address a) {
-  LargePage* page = FindPage(a);
-  if (page != NULL) {
-    return page->GetObject();
-  }
-  return Smi::FromInt(0);  // Signaling not found.
-}
-
-
-LargePage* LargeObjectSpace::FindPage(Address a) {
-  uintptr_t key = reinterpret_cast<uintptr_t>(a) / MemoryChunk::kAlignment;
-  HashMap::Entry* e = chunk_map_.Lookup(reinterpret_cast<void*>(key),
-                                        static_cast<uint32_t>(key),
-                                        false);
-  if (e != NULL) {
-    ASSERT(e->value != NULL);
-    LargePage* page = reinterpret_cast<LargePage*>(e->value);
-    ASSERT(page->is_valid());
-    if (page->Contains(a)) {
-      return page;
-    }
-  }
-  return NULL;
-}
-
-
-void LargeObjectSpace::FreeUnmarkedObjects() {
-  LargePage* previous = NULL;
-  LargePage* current = first_page_;
-  while (current != NULL) {
-    HeapObject* object = current->GetObject();
-    // Can this large page contain pointers to non-trivial objects.  No other
-    // pointer object is this big.
-    bool is_pointer_object = object->IsFixedArray();
-    MarkBit mark_bit = Marking::MarkBitFrom(object);
-    if (mark_bit.Get()) {
-      mark_bit.Clear();
-      Page::FromAddress(object->address())->ResetProgressBar();
-      Page::FromAddress(object->address())->ResetLiveBytes();
-      previous = current;
-      current = current->next_page();
-    } else {
-      LargePage* page = current;
-      // Cut the chunk out from the chunk list.
-      current = current->next_page();
-      if (previous == NULL) {
-        first_page_ = current;
-      } else {
-        previous->set_next_page(current);
-      }
-
-      // Free the chunk.
-      heap()->mark_compact_collector()->ReportDeleteIfNeeded(
-          object, heap()->isolate());
-      size_ -= static_cast<int>(page->size());
-      objects_size_ -= object->Size();
-      page_count_--;
-
-      // Remove entries belonging to this page.
-      // Use variable alignment to help pass length check (<= 80 characters)
-      // of single line in tools/presubmit.py.
-      const intptr_t alignment = MemoryChunk::kAlignment;
-      uintptr_t base = reinterpret_cast<uintptr_t>(page)/alignment;
-      uintptr_t limit = base + (page->size()-1)/alignment;
-      for (uintptr_t key = base; key <= limit; key++) {
-        chunk_map_.Remove(reinterpret_cast<void*>(key),
-                          static_cast<uint32_t>(key));
-      }
-
-      if (is_pointer_object) {
-        heap()->QueueMemoryChunkForFree(page);
-      } else {
-        heap()->isolate()->memory_allocator()->Free(page);
-      }
-    }
-  }
-  heap()->FreeQueuedChunks();
-}
-
-
-bool LargeObjectSpace::Contains(HeapObject* object) {
-  Address address = object->address();
-  MemoryChunk* chunk = MemoryChunk::FromAddress(address);
-
-  bool owned = (chunk->owner() == this);
-
-  SLOW_ASSERT(!owned || FindObject(address)->IsHeapObject());
-
-  return owned;
-}
-
-
-#ifdef VERIFY_HEAP
-// We do not assume that the large object iterator works, because it depends
-// on the invariants we are checking during verification.
-void LargeObjectSpace::Verify() {
-  for (LargePage* chunk = first_page_;
-       chunk != NULL;
-       chunk = chunk->next_page()) {
-    // Each chunk contains an object that starts at the large object page's
-    // object area start.
-    HeapObject* object = chunk->GetObject();
-    Page* page = Page::FromAddress(object->address());
-    CHECK(object->address() == page->area_start());
-
-    // The first word should be a map, and we expect all map pointers to be
-    // in map space.
-    Map* map = object->map();
-    CHECK(map->IsMap());
-    CHECK(heap()->map_space()->Contains(map));
-
-    // We have only code, sequential strings, external strings
-    // (sequential strings that have been morphed into external
-    // strings), fixed arrays, and byte arrays in large object space.
-    CHECK(object->IsCode() || object->IsSeqString() ||
-           object->IsExternalString() || object->IsFixedArray() ||
-           object->IsFixedDoubleArray() || object->IsByteArray());
-
-    // The object itself should look OK.
-    object->ObjectVerify();
-
-    // Byte arrays and strings don't have interior pointers.
-    if (object->IsCode()) {
-      VerifyPointersVisitor code_visitor;
-      object->IterateBody(map->instance_type(),
-                          object->Size(),
-                          &code_visitor);
-    } else if (object->IsFixedArray()) {
-      FixedArray* array = FixedArray::cast(object);
-      for (int j = 0; j < array->length(); j++) {
-        Object* element = array->get(j);
-        if (element->IsHeapObject()) {
-          HeapObject* element_object = HeapObject::cast(element);
-          CHECK(heap()->Contains(element_object));
-          CHECK(element_object->map()->IsMap());
-        }
-      }
-    }
-  }
-}
-#endif
-
-
-#ifdef DEBUG
-void LargeObjectSpace::Print() {
-  LargeObjectIterator it(this);
-  for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
-    obj->Print();
-  }
-}
-
-
-void LargeObjectSpace::ReportStatistics() {
-  PrintF("  size: %" V8_PTR_PREFIX "d\n", size_);
-  int num_objects = 0;
-  ClearHistograms(heap()->isolate());
-  LargeObjectIterator it(this);
-  for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
-    num_objects++;
-    CollectHistogramInfo(obj);
-  }
-
-  PrintF("  number of objects %d, "
-         "size of objects %" V8_PTR_PREFIX "d\n", num_objects, objects_size_);
-  if (num_objects > 0) ReportHistogram(heap()->isolate(), false);
-}
-
-
-void LargeObjectSpace::CollectCodeStatistics() {
-  Isolate* isolate = heap()->isolate();
-  LargeObjectIterator obj_it(this);
-  for (HeapObject* obj = obj_it.Next(); obj != NULL; obj = obj_it.Next()) {
-    if (obj->IsCode()) {
-      Code* code = Code::cast(obj);
-      isolate->code_kind_statistics()[code->kind()] += code->Size();
-    }
-  }
-}
-
-
-void Page::Print() {
-  // Make a best-effort to print the objects in the page.
-  PrintF("Page@%p in %s\n",
-         this->address(),
-         AllocationSpaceName(this->owner()->identity()));
-  printf(" --------------------------------------\n");
-  HeapObjectIterator objects(this, heap()->GcSafeSizeOfOldObjectFunction());
-  unsigned mark_size = 0;
-  for (HeapObject* object = objects.Next();
-       object != NULL;
-       object = objects.Next()) {
-    bool is_marked = Marking::MarkBitFrom(object).Get();
-    PrintF(" %c ", (is_marked ? '!' : ' '));  // Indent a little.
-    if (is_marked) {
-      mark_size += heap()->GcSafeSizeOfOldObjectFunction()(object);
-    }
-    object->ShortPrint();
-    PrintF("\n");
-  }
-  printf(" --------------------------------------\n");
-  printf(" Marked: %x, LiveCount: %x\n", mark_size, LiveBytes());
-}
-
-#endif  // DEBUG
-
-} }  // namespace v8::internal