Roll V8 back to 3.6

Roll back to V8 3.6 to fix x86 build, we don't have ucontext.h.

This reverts commits:
5d4cdbf7a67d3662fa0bee4efdb7edd8daec9b0b
c7cc028aaeedbbfa11c11d0b7b243b3d9e837ed9
592a9fc1d8ea420377a2e7efd0600e20b058be2b

Bug: 5688872
Change-Id: Ic961bb5e65b778e98bbfb71cce71d99fa949e995

1 files changed, 0 insertions, 937 deletions

diff --git a/src/incremental-marking.cc b/src/incremental-marking.cc
deleted file mode 100644
index 8fe89b4a..00000000
--- a/src/incremental-marking.cc
+++ /dev/null
@@ -1,937 +0,0 @@
-// Copyright 2011 the V8 project authors. All rights reserved.
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-//       notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-//       copyright notice, this list of conditions and the following
-//       disclaimer in the documentation and/or other materials provided
-//       with the distribution.
-//     * Neither the name of Google Inc. nor the names of its
-//       contributors may be used to endorse or promote products derived
-//       from this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-#include "v8.h"
-
-#include "incremental-marking.h"
-
-#include "code-stubs.h"
-#include "compilation-cache.h"
-#include "v8conversions.h"
-
-namespace v8 {
-namespace internal {
-
-
-IncrementalMarking::IncrementalMarking(Heap* heap)
-    : heap_(heap),
-      state_(STOPPED),
-      marking_deque_memory_(NULL),
-      marking_deque_memory_committed_(false),
-      steps_count_(0),
-      steps_took_(0),
-      longest_step_(0.0),
-      old_generation_space_available_at_start_of_incremental_(0),
-      old_generation_space_used_at_start_of_incremental_(0),
-      steps_count_since_last_gc_(0),
-      steps_took_since_last_gc_(0),
-      should_hurry_(false),
-      allocation_marking_factor_(0),
-      allocated_(0),
-      no_marking_scope_depth_(0) {
-}
-
-
-void IncrementalMarking::TearDown() {
-  delete marking_deque_memory_;
-}
-
-
-void IncrementalMarking::RecordWriteSlow(HeapObject* obj,
-                                         Object** slot,
-                                         Object* value) {
-  if (BaseRecordWrite(obj, slot, value) && is_compacting_ && slot != NULL) {
-    MarkBit obj_bit = Marking::MarkBitFrom(obj);
-    if (Marking::IsBlack(obj_bit)) {
-      // Object is not going to be rescanned we need to record the slot.
-      heap_->mark_compact_collector()->RecordSlot(
-          HeapObject::RawField(obj, 0), slot, value);
-    }
-  }
-}
-
-
-void IncrementalMarking::RecordWriteFromCode(HeapObject* obj,
-                                             Object* value,
-                                             Isolate* isolate) {
-  ASSERT(obj->IsHeapObject());
-
-  // Fast cases should already be covered by RecordWriteStub.
-  ASSERT(value->IsHeapObject());
-  ASSERT(!value->IsHeapNumber());
-  ASSERT(!value->IsString() ||
-         value->IsConsString() ||
-         value->IsSlicedString());
-  ASSERT(Marking::IsWhite(Marking::MarkBitFrom(HeapObject::cast(value))));
-
-  IncrementalMarking* marking = isolate->heap()->incremental_marking();
-  ASSERT(!marking->is_compacting_);
-  marking->RecordWrite(obj, NULL, value);
-}
-
-
-void IncrementalMarking::RecordWriteForEvacuationFromCode(HeapObject* obj,
-                                                          Object** slot,
-                                                          Isolate* isolate) {
-  IncrementalMarking* marking = isolate->heap()->incremental_marking();
-  ASSERT(marking->is_compacting_);
-  marking->RecordWrite(obj, slot, *slot);
-}
-
-
-void IncrementalMarking::RecordCodeTargetPatch(Code* host,
-                                               Address pc,
-                                               HeapObject* value) {
-  if (IsMarking()) {
-    RelocInfo rinfo(pc, RelocInfo::CODE_TARGET, 0, host);
-    RecordWriteIntoCode(host, &rinfo, value);
-  }
-}
-
-
-void IncrementalMarking::RecordCodeTargetPatch(Address pc, HeapObject* value) {
-  if (IsMarking()) {
-    Code* host = heap_->isolate()->inner_pointer_to_code_cache()->
-        GcSafeFindCodeForInnerPointer(pc);
-    RelocInfo rinfo(pc, RelocInfo::CODE_TARGET, 0, host);
-    RecordWriteIntoCode(host, &rinfo, value);
-  }
-}
-
-
-void IncrementalMarking::RecordWriteOfCodeEntrySlow(JSFunction* host,
-                                                Object** slot,
-                                                Code* value) {
-  if (BaseRecordWrite(host, slot, value) && is_compacting_) {
-    ASSERT(slot != NULL);
-    heap_->mark_compact_collector()->
-        RecordCodeEntrySlot(reinterpret_cast<Address>(slot), value);
-  }
-}
-
-
-void IncrementalMarking::RecordWriteIntoCodeSlow(HeapObject* obj,
-                                                 RelocInfo* rinfo,
-                                                 Object* value) {
-  MarkBit value_bit = Marking::MarkBitFrom(HeapObject::cast(value));
-  if (Marking::IsWhite(value_bit)) {
-    MarkBit obj_bit = Marking::MarkBitFrom(obj);
-    if (Marking::IsBlack(obj_bit)) {
-      BlackToGreyAndUnshift(obj, obj_bit);
-      RestartIfNotMarking();
-    }
-    // Object is either grey or white.  It will be scanned if survives.
-    return;
-  }
-
-  if (is_compacting_) {
-    MarkBit obj_bit = Marking::MarkBitFrom(obj);
-    if (Marking::IsBlack(obj_bit)) {
-      // Object is not going to be rescanned.  We need to record the slot.
-      heap_->mark_compact_collector()->RecordRelocSlot(rinfo,
-                                                       Code::cast(value));
-    }
-  }
-}
-
-
-class IncrementalMarkingMarkingVisitor : public ObjectVisitor {
- public:
-  IncrementalMarkingMarkingVisitor(Heap* heap,
-                                   IncrementalMarking* incremental_marking)
-      : heap_(heap),
-        incremental_marking_(incremental_marking) {
-  }
-
-  void VisitEmbeddedPointer(RelocInfo* rinfo) {
-    ASSERT(rinfo->rmode() == RelocInfo::EMBEDDED_OBJECT);
-    Object* target = rinfo->target_object();
-    if (target->NonFailureIsHeapObject()) {
-      heap_->mark_compact_collector()->RecordRelocSlot(rinfo, target);
-      MarkObject(target);
-    }
-  }
-
-  void VisitCodeTarget(RelocInfo* rinfo) {
-    ASSERT(RelocInfo::IsCodeTarget(rinfo->rmode()));
-    Code* target = Code::GetCodeFromTargetAddress(rinfo->target_address());
-    if (FLAG_cleanup_code_caches_at_gc && target->is_inline_cache_stub()
-        && (target->ic_age() != heap_->global_ic_age())) {
-      IC::Clear(rinfo->pc());
-      target = Code::GetCodeFromTargetAddress(rinfo->target_address());
-    }
-    heap_->mark_compact_collector()->RecordRelocSlot(rinfo, Code::cast(target));
-    MarkObject(target);
-  }
-
-  void VisitDebugTarget(RelocInfo* rinfo) {
-    ASSERT((RelocInfo::IsJSReturn(rinfo->rmode()) &&
-            rinfo->IsPatchedReturnSequence()) ||
-           (RelocInfo::IsDebugBreakSlot(rinfo->rmode()) &&
-            rinfo->IsPatchedDebugBreakSlotSequence()));
-    Object* target = Code::GetCodeFromTargetAddress(rinfo->call_address());
-    heap_->mark_compact_collector()->RecordRelocSlot(rinfo, Code::cast(target));
-    MarkObject(target);
-  }
-
-  void VisitCodeEntry(Address entry_address) {
-    Object* target = Code::GetObjectFromEntryAddress(entry_address);
-    heap_->mark_compact_collector()->
-        RecordCodeEntrySlot(entry_address, Code::cast(target));
-    MarkObject(target);
-  }
-
-  void VisitPointer(Object** p) {
-    Object* obj = *p;
-    if (obj->NonFailureIsHeapObject()) {
-      heap_->mark_compact_collector()->RecordSlot(p, p, obj);
-      MarkObject(obj);
-    }
-  }
-
-  void VisitPointers(Object** start, Object** end) {
-    for (Object** p = start; p < end; p++) {
-      Object* obj = *p;
-      if (obj->NonFailureIsHeapObject()) {
-        heap_->mark_compact_collector()->RecordSlot(start, p, obj);
-        MarkObject(obj);
-      }
-    }
-  }
-
- private:
-  // Mark object pointed to by p.
-  INLINE(void MarkObject(Object* obj)) {
-    HeapObject* heap_object = HeapObject::cast(obj);
-    MarkBit mark_bit = Marking::MarkBitFrom(heap_object);
-    if (mark_bit.data_only()) {
-      if (incremental_marking_->MarkBlackOrKeepGrey(mark_bit)) {
-        MemoryChunk::IncrementLiveBytesFromGC(heap_object->address(),
-                                              heap_object->Size());
-      }
-    } else if (Marking::IsWhite(mark_bit)) {
-      incremental_marking_->WhiteToGreyAndPush(heap_object, mark_bit);
-    }
-  }
-
-  Heap* heap_;
-  IncrementalMarking* incremental_marking_;
-};
-
-
-class IncrementalMarkingRootMarkingVisitor : public ObjectVisitor {
- public:
-  IncrementalMarkingRootMarkingVisitor(Heap* heap,
-                                       IncrementalMarking* incremental_marking)
-      : heap_(heap),
-        incremental_marking_(incremental_marking) {
-  }
-
-  void VisitPointer(Object** p) {
-    MarkObjectByPointer(p);
-  }
-
-  void VisitPointers(Object** start, Object** end) {
-    for (Object** p = start; p < end; p++) MarkObjectByPointer(p);
-  }
-
- private:
-  void MarkObjectByPointer(Object** p) {
-    Object* obj = *p;
-    if (!obj->IsHeapObject()) return;
-
-    HeapObject* heap_object = HeapObject::cast(obj);
-    MarkBit mark_bit = Marking::MarkBitFrom(heap_object);
-    if (mark_bit.data_only()) {
-      if (incremental_marking_->MarkBlackOrKeepGrey(mark_bit)) {
-          MemoryChunk::IncrementLiveBytesFromGC(heap_object->address(),
-                                                heap_object->Size());
-      }
-    } else {
-      if (Marking::IsWhite(mark_bit)) {
-        incremental_marking_->WhiteToGreyAndPush(heap_object, mark_bit);
-      }
-    }
-  }
-
-  Heap* heap_;
-  IncrementalMarking* incremental_marking_;
-};
-
-
-void IncrementalMarking::SetOldSpacePageFlags(MemoryChunk* chunk,
-                                              bool is_marking,
-                                              bool is_compacting) {
-  if (is_marking) {
-    chunk->SetFlag(MemoryChunk::POINTERS_TO_HERE_ARE_INTERESTING);
-    chunk->SetFlag(MemoryChunk::POINTERS_FROM_HERE_ARE_INTERESTING);
-
-    // It's difficult to filter out slots recorded for large objects.
-    if (chunk->owner()->identity() == LO_SPACE &&
-        chunk->size() > static_cast<size_t>(Page::kPageSize) &&
-        is_compacting) {
-      chunk->SetFlag(MemoryChunk::RESCAN_ON_EVACUATION);
-    }
-  } else if (chunk->owner()->identity() == CELL_SPACE ||
-             chunk->scan_on_scavenge()) {
-    chunk->ClearFlag(MemoryChunk::POINTERS_TO_HERE_ARE_INTERESTING);
-    chunk->ClearFlag(MemoryChunk::POINTERS_FROM_HERE_ARE_INTERESTING);
-  } else {
-    chunk->ClearFlag(MemoryChunk::POINTERS_TO_HERE_ARE_INTERESTING);
-    chunk->SetFlag(MemoryChunk::POINTERS_FROM_HERE_ARE_INTERESTING);
-  }
-}
-
-
-void IncrementalMarking::SetNewSpacePageFlags(NewSpacePage* chunk,
-                                              bool is_marking) {
-  chunk->SetFlag(MemoryChunk::POINTERS_TO_HERE_ARE_INTERESTING);
-  if (is_marking) {
-    chunk->SetFlag(MemoryChunk::POINTERS_FROM_HERE_ARE_INTERESTING);
-  } else {
-    chunk->ClearFlag(MemoryChunk::POINTERS_FROM_HERE_ARE_INTERESTING);
-  }
-  chunk->SetFlag(MemoryChunk::SCAN_ON_SCAVENGE);
-}
-
-
-void IncrementalMarking::DeactivateIncrementalWriteBarrierForSpace(
-    PagedSpace* space) {
-  PageIterator it(space);
-  while (it.has_next()) {
-    Page* p = it.next();
-    SetOldSpacePageFlags(p, false, false);
-  }
-}
-
-
-void IncrementalMarking::DeactivateIncrementalWriteBarrierForSpace(
-    NewSpace* space) {
-  NewSpacePageIterator it(space);
-  while (it.has_next()) {
-    NewSpacePage* p = it.next();
-    SetNewSpacePageFlags(p, false);
-  }
-}
-
-
-void IncrementalMarking::DeactivateIncrementalWriteBarrier() {
-  DeactivateIncrementalWriteBarrierForSpace(heap_->old_pointer_space());
-  DeactivateIncrementalWriteBarrierForSpace(heap_->old_data_space());
-  DeactivateIncrementalWriteBarrierForSpace(heap_->cell_space());
-  DeactivateIncrementalWriteBarrierForSpace(heap_->map_space());
-  DeactivateIncrementalWriteBarrierForSpace(heap_->code_space());
-  DeactivateIncrementalWriteBarrierForSpace(heap_->new_space());
-
-  LargePage* lop = heap_->lo_space()->first_page();
-  while (lop->is_valid()) {
-    SetOldSpacePageFlags(lop, false, false);
-    lop = lop->next_page();
-  }
-}
-
-
-void IncrementalMarking::ActivateIncrementalWriteBarrier(PagedSpace* space) {
-  PageIterator it(space);
-  while (it.has_next()) {
-    Page* p = it.next();
-    SetOldSpacePageFlags(p, true, is_compacting_);
-  }
-}
-
-
-void IncrementalMarking::ActivateIncrementalWriteBarrier(NewSpace* space) {
-  NewSpacePageIterator it(space->ToSpaceStart(), space->ToSpaceEnd());
-  while (it.has_next()) {
-    NewSpacePage* p = it.next();
-    SetNewSpacePageFlags(p, true);
-  }
-}
-
-
-void IncrementalMarking::ActivateIncrementalWriteBarrier() {
-  ActivateIncrementalWriteBarrier(heap_->old_pointer_space());
-  ActivateIncrementalWriteBarrier(heap_->old_data_space());
-  ActivateIncrementalWriteBarrier(heap_->cell_space());
-  ActivateIncrementalWriteBarrier(heap_->map_space());
-  ActivateIncrementalWriteBarrier(heap_->code_space());
-  ActivateIncrementalWriteBarrier(heap_->new_space());
-
-  LargePage* lop = heap_->lo_space()->first_page();
-  while (lop->is_valid()) {
-    SetOldSpacePageFlags(lop, true, is_compacting_);
-    lop = lop->next_page();
-  }
-}
-
-
-bool IncrementalMarking::WorthActivating() {
-#ifndef DEBUG
-  static const intptr_t kActivationThreshold = 8 * MB;
-#else
-  // TODO(gc) consider setting this to some low level so that some
-  // debug tests run with incremental marking and some without.
-  static const intptr_t kActivationThreshold = 0;
-#endif
-
-  return !FLAG_expose_gc &&
-      FLAG_incremental_marking &&
-      !Serializer::enabled() &&
-      heap_->PromotedSpaceSizeOfObjects() > kActivationThreshold;
-}
-
-
-void IncrementalMarking::ActivateGeneratedStub(Code* stub) {
-  ASSERT(RecordWriteStub::GetMode(stub) ==
-         RecordWriteStub::STORE_BUFFER_ONLY);
-
-  if (!IsMarking()) {
-    // Initially stub is generated in STORE_BUFFER_ONLY mode thus
-    // we don't need to do anything if incremental marking is
-    // not active.
-  } else if (IsCompacting()) {
-    RecordWriteStub::Patch(stub, RecordWriteStub::INCREMENTAL_COMPACTION);
-  } else {
-    RecordWriteStub::Patch(stub, RecordWriteStub::INCREMENTAL);
-  }
-}
-
-
-static void PatchIncrementalMarkingRecordWriteStubs(
-    Heap* heap, RecordWriteStub::Mode mode) {
-  UnseededNumberDictionary* stubs = heap->code_stubs();
-
-  int capacity = stubs->Capacity();
-  for (int i = 0; i < capacity; i++) {
-    Object* k = stubs->KeyAt(i);
-    if (stubs->IsKey(k)) {
-      uint32_t key = NumberToUint32(k);
-
-      if (CodeStub::MajorKeyFromKey(key) ==
-          CodeStub::RecordWrite) {
-        Object* e = stubs->ValueAt(i);
-        if (e->IsCode()) {
-          RecordWriteStub::Patch(Code::cast(e), mode);
-        }
-      }
-    }
-  }
-}
-
-
-void IncrementalMarking::EnsureMarkingDequeIsCommitted() {
-  if (marking_deque_memory_ == NULL) {
-    marking_deque_memory_ = new VirtualMemory(4 * MB);
-  }
-  if (!marking_deque_memory_committed_) {
-    bool success = marking_deque_memory_->Commit(
-        reinterpret_cast<Address>(marking_deque_memory_->address()),
-        marking_deque_memory_->size(),
-        false);  // Not executable.
-    CHECK(success);
-    marking_deque_memory_committed_ = true;
-  }
-}
-
-void IncrementalMarking::UncommitMarkingDeque() {
-  if (state_ == STOPPED && marking_deque_memory_committed_) {
-    bool success = marking_deque_memory_->Uncommit(
-        reinterpret_cast<Address>(marking_deque_memory_->address()),
-        marking_deque_memory_->size());
-    CHECK(success);
-    marking_deque_memory_committed_ = false;
-  }
-}
-
-
-void IncrementalMarking::Start() {
-  if (FLAG_trace_incremental_marking) {
-    PrintF("[IncrementalMarking] Start\n");
-  }
-  ASSERT(FLAG_incremental_marking);
-  ASSERT(state_ == STOPPED);
-
-  ResetStepCounters();
-
-  if (heap_->old_pointer_space()->IsSweepingComplete() &&
-      heap_->old_data_space()->IsSweepingComplete()) {
-    StartMarking(ALLOW_COMPACTION);
-  } else {
-    if (FLAG_trace_incremental_marking) {
-      PrintF("[IncrementalMarking] Start sweeping.\n");
-    }
-    state_ = SWEEPING;
-  }
-
-  heap_->new_space()->LowerInlineAllocationLimit(kAllocatedThreshold);
-}
-
-
-static void MarkObjectGreyDoNotEnqueue(Object* obj) {
-  if (obj->IsHeapObject()) {
-    HeapObject* heap_obj = HeapObject::cast(obj);
-    MarkBit mark_bit = Marking::MarkBitFrom(HeapObject::cast(obj));
-    if (Marking::IsBlack(mark_bit)) {
-      MemoryChunk::IncrementLiveBytesFromGC(heap_obj->address(),
-                                            -heap_obj->Size());
-    }
-    Marking::AnyToGrey(mark_bit);
-  }
-}
-
-
-void IncrementalMarking::StartMarking(CompactionFlag flag) {
-  if (FLAG_trace_incremental_marking) {
-    PrintF("[IncrementalMarking] Start marking\n");
-  }
-
-  is_compacting_ = !FLAG_never_compact && (flag == ALLOW_COMPACTION) &&
-      heap_->mark_compact_collector()->StartCompaction(
-          MarkCompactCollector::INCREMENTAL_COMPACTION);
-
-  state_ = MARKING;
-
-  RecordWriteStub::Mode mode = is_compacting_ ?
-      RecordWriteStub::INCREMENTAL_COMPACTION : RecordWriteStub::INCREMENTAL;
-
-  PatchIncrementalMarkingRecordWriteStubs(heap_, mode);
-
-  EnsureMarkingDequeIsCommitted();
-
-  // Initialize marking stack.
-  Address addr = static_cast<Address>(marking_deque_memory_->address());
-  size_t size = marking_deque_memory_->size();
-  if (FLAG_force_marking_deque_overflows) size = 64 * kPointerSize;
-  marking_deque_.Initialize(addr, addr + size);
-
-  ActivateIncrementalWriteBarrier();
-
-#ifdef DEBUG
-  // Marking bits are cleared by the sweeper.
-  if (FLAG_verify_heap) {
-    heap_->mark_compact_collector()->VerifyMarkbitsAreClean();
-  }
-#endif
-
-  heap_->CompletelyClearInstanceofCache();
-  heap_->isolate()->compilation_cache()->MarkCompactPrologue();
-
-  if (FLAG_cleanup_code_caches_at_gc) {
-    // We will mark cache black with a separate pass
-    // when we finish marking.
-    MarkObjectGreyDoNotEnqueue(heap_->polymorphic_code_cache());
-  }
-
-  // Mark strong roots grey.
-  IncrementalMarkingRootMarkingVisitor visitor(heap_, this);
-  heap_->IterateStrongRoots(&visitor, VISIT_ONLY_STRONG);
-
-  // Ready to start incremental marking.
-  if (FLAG_trace_incremental_marking) {
-    PrintF("[IncrementalMarking] Running\n");
-  }
-}
-
-
-void IncrementalMarking::PrepareForScavenge() {
-  if (!IsMarking()) return;
-  NewSpacePageIterator it(heap_->new_space()->FromSpaceStart(),
-                          heap_->new_space()->FromSpaceEnd());
-  while (it.has_next()) {
-    Bitmap::Clear(it.next());
-  }
-}
-
-
-void IncrementalMarking::UpdateMarkingDequeAfterScavenge() {
-  if (!IsMarking()) return;
-
-  int current = marking_deque_.bottom();
-  int mask = marking_deque_.mask();
-  int limit = marking_deque_.top();
-  HeapObject** array = marking_deque_.array();
-  int new_top = current;
-
-  Map* filler_map = heap_->one_pointer_filler_map();
-
-  while (current != limit) {
-    HeapObject* obj = array[current];
-    ASSERT(obj->IsHeapObject());
-    current = ((current + 1) & mask);
-    if (heap_->InNewSpace(obj)) {
-      MapWord map_word = obj->map_word();
-      if (map_word.IsForwardingAddress()) {
-        HeapObject* dest = map_word.ToForwardingAddress();
-        array[new_top] = dest;
-        new_top = ((new_top + 1) & mask);
-        ASSERT(new_top != marking_deque_.bottom());
-#ifdef DEBUG
-        MarkBit mark_bit = Marking::MarkBitFrom(obj);
-        ASSERT(Marking::IsGrey(mark_bit) ||
-               (obj->IsFiller() && Marking::IsWhite(mark_bit)));
-#endif
-      }
-    } else if (obj->map() != filler_map) {
-      // Skip one word filler objects that appear on the
-      // stack when we perform in place array shift.
-      array[new_top] = obj;
-      new_top = ((new_top + 1) & mask);
-      ASSERT(new_top != marking_deque_.bottom());
-#ifdef DEBUG
-        MarkBit mark_bit = Marking::MarkBitFrom(obj);
-        ASSERT(Marking::IsGrey(mark_bit) ||
-               (obj->IsFiller() && Marking::IsWhite(mark_bit)));
-#endif
-    }
-  }
-  marking_deque_.set_top(new_top);
-
-  steps_took_since_last_gc_ = 0;
-  steps_count_since_last_gc_ = 0;
-  longest_step_ = 0.0;
-}
-
-
-void IncrementalMarking::VisitGlobalContext(Context* ctx, ObjectVisitor* v) {
-  v->VisitPointers(
-      HeapObject::RawField(
-          ctx, Context::MarkCompactBodyDescriptor::kStartOffset),
-      HeapObject::RawField(
-          ctx, Context::MarkCompactBodyDescriptor::kEndOffset));
-
-  MarkCompactCollector* collector = heap_->mark_compact_collector();
-  for (int idx = Context::FIRST_WEAK_SLOT;
-       idx < Context::GLOBAL_CONTEXT_SLOTS;
-       ++idx) {
-    Object** slot =
-        HeapObject::RawField(ctx, FixedArray::OffsetOfElementAt(idx));
-    collector->RecordSlot(slot, slot, *slot);
-  }
-}
-
-
-void IncrementalMarking::Hurry() {
-  if (state() == MARKING) {
-    double start = 0.0;
-    if (FLAG_trace_incremental_marking) {
-      PrintF("[IncrementalMarking] Hurry\n");
-      start = OS::TimeCurrentMillis();
-    }
-    // TODO(gc) hurry can mark objects it encounters black as mutator
-    // was stopped.
-    Map* filler_map = heap_->one_pointer_filler_map();
-    Map* global_context_map = heap_->global_context_map();
-    IncrementalMarkingMarkingVisitor marking_visitor(heap_, this);
-    while (!marking_deque_.IsEmpty()) {
-      HeapObject* obj = marking_deque_.Pop();
-
-      // Explicitly skip one word fillers. Incremental markbit patterns are
-      // correct only for objects that occupy at least two words.
-      Map* map = obj->map();
-      if (map == filler_map) {
-        continue;
-      } else if (map == global_context_map) {
-        // Global contexts have weak fields.
-        VisitGlobalContext(Context::cast(obj), &marking_visitor);
-      } else {
-        obj->Iterate(&marking_visitor);
-      }
-
-      MarkBit mark_bit = Marking::MarkBitFrom(obj);
-      ASSERT(!Marking::IsBlack(mark_bit));
-      Marking::MarkBlack(mark_bit);
-      MemoryChunk::IncrementLiveBytesFromGC(obj->address(), obj->Size());
-    }
-    state_ = COMPLETE;
-    if (FLAG_trace_incremental_marking) {
-      double end = OS::TimeCurrentMillis();
-      PrintF("[IncrementalMarking] Complete (hurry), spent %d ms.\n",
-             static_cast<int>(end - start));
-    }
-  }
-
-  if (FLAG_cleanup_code_caches_at_gc) {
-    PolymorphicCodeCache* poly_cache = heap_->polymorphic_code_cache();
-    Marking::GreyToBlack(Marking::MarkBitFrom(poly_cache));
-    MemoryChunk::IncrementLiveBytesFromGC(poly_cache->address(),
-                                          PolymorphicCodeCache::kSize);
-  }
-
-  Object* context = heap_->global_contexts_list();
-  while (!context->IsUndefined()) {
-    // GC can happen when the context is not fully initialized,
-    // so the cache can be undefined.
-    HeapObject* cache = HeapObject::cast(
-        Context::cast(context)->get(Context::NORMALIZED_MAP_CACHE_INDEX));
-    if (!cache->IsUndefined()) {
-      MarkBit mark_bit = Marking::MarkBitFrom(cache);
-      if (Marking::IsGrey(mark_bit)) {
-        Marking::GreyToBlack(mark_bit);
-        MemoryChunk::IncrementLiveBytesFromGC(cache->address(), cache->Size());
-      }
-    }
-    context = Context::cast(context)->get(Context::NEXT_CONTEXT_LINK);
-  }
-}
-
-
-void IncrementalMarking::Abort() {
-  if (IsStopped()) return;
-  if (FLAG_trace_incremental_marking) {
-    PrintF("[IncrementalMarking] Aborting.\n");
-  }
-  heap_->new_space()->LowerInlineAllocationLimit(0);
-  IncrementalMarking::set_should_hurry(false);
-  ResetStepCounters();
-  if (IsMarking()) {
-    PatchIncrementalMarkingRecordWriteStubs(heap_,
-                                            RecordWriteStub::STORE_BUFFER_ONLY);
-    DeactivateIncrementalWriteBarrier();
-
-    if (is_compacting_) {
-      LargeObjectIterator it(heap_->lo_space());
-      for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
-        Page* p = Page::FromAddress(obj->address());
-        if (p->IsFlagSet(Page::RESCAN_ON_EVACUATION)) {
-          p->ClearFlag(Page::RESCAN_ON_EVACUATION);
-        }
-      }
-    }
-  }
-  heap_->isolate()->stack_guard()->Continue(GC_REQUEST);
-  state_ = STOPPED;
-  is_compacting_ = false;
-}
-
-
-void IncrementalMarking::Finalize() {
-  Hurry();
-  state_ = STOPPED;
-  is_compacting_ = false;
-  heap_->new_space()->LowerInlineAllocationLimit(0);
-  IncrementalMarking::set_should_hurry(false);
-  ResetStepCounters();
-  PatchIncrementalMarkingRecordWriteStubs(heap_,
-                                          RecordWriteStub::STORE_BUFFER_ONLY);
-  DeactivateIncrementalWriteBarrier();
-  ASSERT(marking_deque_.IsEmpty());
-  heap_->isolate()->stack_guard()->Continue(GC_REQUEST);
-}
-
-
-void IncrementalMarking::MarkingComplete() {
-  state_ = COMPLETE;
-  // We will set the stack guard to request a GC now.  This will mean the rest
-  // of the GC gets performed as soon as possible (we can't do a GC here in a
-  // record-write context).  If a few things get allocated between now and then
-  // that shouldn't make us do a scavenge and keep being incremental, so we set
-  // the should-hurry flag to indicate that there can't be much work left to do.
-  set_should_hurry(true);
-  if (FLAG_trace_incremental_marking) {
-    PrintF("[IncrementalMarking] Complete (normal).\n");
-  }
-  if (!heap_->idle_notification_will_schedule_next_gc()) {
-    heap_->isolate()->stack_guard()->RequestGC();
-  }
-}
-
-
-void IncrementalMarking::Step(intptr_t allocated_bytes) {
-  if (heap_->gc_state() != Heap::NOT_IN_GC ||
-      !FLAG_incremental_marking ||
-      !FLAG_incremental_marking_steps ||
-      (state_ != SWEEPING && state_ != MARKING)) {
-    return;
-  }
-
-  allocated_ += allocated_bytes;
-
-  if (allocated_ < kAllocatedThreshold) return;
-
-  if (state_ == MARKING && no_marking_scope_depth_ > 0) return;
-
-  intptr_t bytes_to_process = allocated_ * allocation_marking_factor_;
-  bytes_scanned_ += bytes_to_process;
-
-  double start = 0;
-
-  if (FLAG_trace_incremental_marking || FLAG_trace_gc) {
-    start = OS::TimeCurrentMillis();
-  }
-
-  if (state_ == SWEEPING) {
-    if (heap_->AdvanceSweepers(static_cast<int>(bytes_to_process))) {
-      bytes_scanned_ = 0;
-      StartMarking(PREVENT_COMPACTION);
-    }
-  } else if (state_ == MARKING) {
-    Map* filler_map = heap_->one_pointer_filler_map();
-    Map* global_context_map = heap_->global_context_map();
-    IncrementalMarkingMarkingVisitor marking_visitor(heap_, this);
-    while (!marking_deque_.IsEmpty() && bytes_to_process > 0) {
-      HeapObject* obj = marking_deque_.Pop();
-
-      // Explicitly skip one word fillers. Incremental markbit patterns are
-      // correct only for objects that occupy at least two words.
-      Map* map = obj->map();
-      if (map == filler_map) continue;
-
-      if (obj->IsMap()) {
-        Map* map = Map::cast(obj);
-        heap_->ClearCacheOnMap(map);
-      }
-
-
-      int size = obj->SizeFromMap(map);
-      bytes_to_process -= size;
-      MarkBit map_mark_bit = Marking::MarkBitFrom(map);
-      if (Marking::IsWhite(map_mark_bit)) {
-        WhiteToGreyAndPush(map, map_mark_bit);
-      }
-
-      // TODO(gc) switch to static visitor instead of normal visitor.
-      if (map == global_context_map) {
-        // Global contexts have weak fields.
-        Context* ctx = Context::cast(obj);
-
-        // We will mark cache black with a separate pass
-        // when we finish marking.
-        MarkObjectGreyDoNotEnqueue(ctx->normalized_map_cache());
-
-        VisitGlobalContext(ctx, &marking_visitor);
-      } else {
-        obj->IterateBody(map->instance_type(), size, &marking_visitor);
-      }
-
-      MarkBit obj_mark_bit = Marking::MarkBitFrom(obj);
-      SLOW_ASSERT(Marking::IsGrey(obj_mark_bit) ||
-                  (obj->IsFiller() && Marking::IsWhite(obj_mark_bit)));
-      Marking::MarkBlack(obj_mark_bit);
-      MemoryChunk::IncrementLiveBytesFromGC(obj->address(), size);
-    }
-    if (marking_deque_.IsEmpty()) MarkingComplete();
-  }
-
-  allocated_ = 0;
-
-  steps_count_++;
-  steps_count_since_last_gc_++;
-
-  bool speed_up = false;
-
-  if ((steps_count_ % kAllocationMarkingFactorSpeedupInterval) == 0) {
-    if (FLAG_trace_gc) {
-      PrintF("Speed up marking after %d steps\n",
-             static_cast<int>(kAllocationMarkingFactorSpeedupInterval));
-    }
-    speed_up = true;
-  }
-
-  bool space_left_is_very_small =
-      (old_generation_space_available_at_start_of_incremental_ < 10 * MB);
-
-  bool only_1_nth_of_space_that_was_available_still_left =
-      (SpaceLeftInOldSpace() * (allocation_marking_factor_ + 1) <
-          old_generation_space_available_at_start_of_incremental_);
-
-  if (space_left_is_very_small ||
-      only_1_nth_of_space_that_was_available_still_left) {
-    if (FLAG_trace_gc) PrintF("Speed up marking because of low space left\n");
-    speed_up = true;
-  }
-
-  bool size_of_old_space_multiplied_by_n_during_marking =
-      (heap_->PromotedTotalSize() >
-       (allocation_marking_factor_ + 1) *
-           old_generation_space_used_at_start_of_incremental_);
-  if (size_of_old_space_multiplied_by_n_during_marking) {
-    speed_up = true;
-    if (FLAG_trace_gc) {
-      PrintF("Speed up marking because of heap size increase\n");
-    }
-  }
-
-  int64_t promoted_during_marking = heap_->PromotedTotalSize()
-      - old_generation_space_used_at_start_of_incremental_;
-  intptr_t delay = allocation_marking_factor_ * MB;
-  intptr_t scavenge_slack = heap_->MaxSemiSpaceSize();
-
-  // We try to scan at at least twice the speed that we are allocating.
-  if (promoted_during_marking > bytes_scanned_ / 2 + scavenge_slack + delay) {
-    if (FLAG_trace_gc) {
-      PrintF("Speed up marking because marker was not keeping up\n");
-    }
-    speed_up = true;
-  }
-
-  if (speed_up) {
-    if (state_ != MARKING) {
-      if (FLAG_trace_gc) {
-        PrintF("Postponing speeding up marking until marking starts\n");
-      }
-    } else {
-      allocation_marking_factor_ += kAllocationMarkingFactorSpeedup;
-      allocation_marking_factor_ = static_cast<int>(
-          Min(kMaxAllocationMarkingFactor,
-              static_cast<intptr_t>(allocation_marking_factor_ * 1.3)));
-      if (FLAG_trace_gc) {
-        PrintF("Marking speed increased to %d\n", allocation_marking_factor_);
-      }
-    }
-  }
-
-  if (FLAG_trace_incremental_marking || FLAG_trace_gc) {
-    double end = OS::TimeCurrentMillis();
-    double delta = (end - start);
-    longest_step_ = Max(longest_step_, delta);
-    steps_took_ += delta;
-    steps_took_since_last_gc_ += delta;
-  }
-}
-
-
-void IncrementalMarking::ResetStepCounters() {
-  steps_count_ = 0;
-  steps_took_ = 0;
-  longest_step_ = 0.0;
-  old_generation_space_available_at_start_of_incremental_ =
-      SpaceLeftInOldSpace();
-  old_generation_space_used_at_start_of_incremental_ =
-      heap_->PromotedTotalSize();
-  steps_count_since_last_gc_ = 0;
-  steps_took_since_last_gc_ = 0;
-  bytes_rescanned_ = 0;
-  allocation_marking_factor_ = kInitialAllocationMarkingFactor;
-  bytes_scanned_ = 0;
-}
-
-
-int64_t IncrementalMarking::SpaceLeftInOldSpace() {
-  return heap_->MaxOldGenerationSize() - heap_->PromotedSpaceSize();
-}
-
-} }  // namespace v8::internal