Delete dead store buffer verification code and code that changes the store buffer in debug mode.

BUG=

Review URL: https://codereview.chromium.org/1009323002

Cr-Commit-Position: refs/heads/master@{#27214}

src/heap/heap.cc

@@ -1575,10 +1575,6 @@ void Heap::Scavenge() {
   Address new_space_front = new_space_.ToSpaceStart();
   promotion_queue_.Initialize();
 
-#ifdef DEBUG
-  store_buffer()->Clean();
-#endif
-
   ScavengeVisitor scavenge_visitor(this);
   // Copy roots.
   IterateRoots(&scavenge_visitor, VISIT_ALL_IN_SCAVENGE);
@@ -4961,143 +4957,6 @@ void Heap::IterateAndMarkPointersToFromSpace(Address start, Address end,
 }
 
 
-#ifdef DEBUG
-typedef bool (*CheckStoreBufferFilter)(Object** addr);
-
-
-bool IsAMapPointerAddress(Object** addr) {
-  uintptr_t a = reinterpret_cast<uintptr_t>(addr);
-  int mod = a % Map::kSize;
-  return mod >= Map::kPointerFieldsBeginOffset &&
-         mod < Map::kPointerFieldsEndOffset;
-}
-
-
-bool EverythingsAPointer(Object** addr) { return true; }
-
-
-static void CheckStoreBuffer(Heap* heap, Object** current, Object** limit,
-                             Object**** store_buffer_position,
-                             Object*** store_buffer_top,
-                             CheckStoreBufferFilter filter,
-                             Address special_garbage_start,
-                             Address special_garbage_end) {
-  Map* free_space_map = heap->free_space_map();
-  for (; current < limit; current++) {
-    Object* o = *current;
-    Address current_address = reinterpret_cast<Address>(current);
-    // Skip free space.
-    if (o == free_space_map) {
-      Address current_address = reinterpret_cast<Address>(current);
-      FreeSpace* free_space =
-          FreeSpace::cast(HeapObject::FromAddress(current_address));
-      int skip = free_space->Size();
-      DCHECK(current_address + skip <= reinterpret_cast<Address>(limit));
-      DCHECK(skip > 0);
-      current_address += skip - kPointerSize;
-      current = reinterpret_cast<Object**>(current_address);
-      continue;
-    }
-    // Skip the current linear allocation space between top and limit which is
-    // unmarked with the free space map, but can contain junk.
-    if (current_address == special_garbage_start &&
-        special_garbage_end != special_garbage_start) {
-      current_address = special_garbage_end - kPointerSize;
-      current = reinterpret_cast<Object**>(current_address);
-      continue;
-    }
-    if (!(*filter)(current)) continue;
-    DCHECK(current_address < special_garbage_start ||
-           current_address >= special_garbage_end);
-    DCHECK(reinterpret_cast<uintptr_t>(o) != kFreeListZapValue);
-    // We have to check that the pointer does not point into new space
-    // without trying to cast it to a heap object since the hash field of
-    // a string can contain values like 1 and 3 which are tagged null
-    // pointers.
-    if (!heap->InNewSpace(o)) continue;
-    while (**store_buffer_position < current &&
-           *store_buffer_position < store_buffer_top) {
-      (*store_buffer_position)++;
-    }
-    if (**store_buffer_position != current ||
-        *store_buffer_position == store_buffer_top) {
-      Object** obj_start = current;
-      while (!(*obj_start)->IsMap()) obj_start--;
-      UNREACHABLE();
-    }
-  }
-}
-
-
-// Check that the store buffer contains all intergenerational pointers by
-// scanning a page and ensuring that all pointers to young space are in the
-// store buffer.
-void Heap::OldPointerSpaceCheckStoreBuffer() {
-  OldSpace* space = old_pointer_space();
-  PageIterator pages(space);
-
-  store_buffer()->SortUniq();
-
-  while (pages.has_next()) {
-    Page* page = pages.next();
-    Object** current = reinterpret_cast<Object**>(page->area_start());
-
-    Address end = page->area_end();
-
-    Object*** store_buffer_position = store_buffer()->Start();
-    Object*** store_buffer_top = store_buffer()->Top();
-
-    Object** limit = reinterpret_cast<Object**>(end);
-    CheckStoreBuffer(this, current, limit, &store_buffer_position,
-                     store_buffer_top, &EverythingsAPointer, space->top(),
-                     space->limit());
-  }
-}
-
-
-void Heap::MapSpaceCheckStoreBuffer() {
-  MapSpace* space = map_space();
-  PageIterator pages(space);
-
-  store_buffer()->SortUniq();
-
-  while (pages.has_next()) {
-    Page* page = pages.next();
-    Object** current = reinterpret_cast<Object**>(page->area_start());
-
-    Address end = page->area_end();
-
-    Object*** store_buffer_position = store_buffer()->Start();
-    Object*** store_buffer_top = store_buffer()->Top();
-
-    Object** limit = reinterpret_cast<Object**>(end);
-    CheckStoreBuffer(this, current, limit, &store_buffer_position,
-                     store_buffer_top, &IsAMapPointerAddress, space->top(),
-                     space->limit());
-  }
-}
-
-
-void Heap::LargeObjectSpaceCheckStoreBuffer() {
-  LargeObjectIterator it(lo_space());
-  for (HeapObject* object = it.Next(); object != NULL; object = it.Next()) {
-    // We only have code, sequential strings, or fixed arrays in large
-    // object space, and only fixed arrays can possibly contain pointers to
-    // the young generation.
-    if (object->IsFixedArray()) {
-      Object*** store_buffer_position = store_buffer()->Start();
-      Object*** store_buffer_top = store_buffer()->Top();
-      Object** current = reinterpret_cast<Object**>(object->address());
-      Object** limit =
-          reinterpret_cast<Object**>(object->address() + object->Size());
-      CheckStoreBuffer(this, current, limit, &store_buffer_position,
-                       store_buffer_top, &EverythingsAPointer, NULL, NULL);
-    }
-  }
-}
-#endif
-
-
 void Heap::IterateRoots(ObjectVisitor* v, VisitMode mode) {
   IterateStrongRoots(v, mode);
   IterateWeakRoots(v, mode);

src/heap/heap.h

@@ -995,10 +995,6 @@ class Heap {
   void Print();
   void PrintHandles();
 
-  void OldPointerSpaceCheckStoreBuffer();
-  void MapSpaceCheckStoreBuffer();
-  void LargeObjectSpaceCheckStoreBuffer();
-
   // Report heap statistics.
   void ReportHeapStatistics(const char* title);
   void ReportCodeStatistics(const char* title);

src/heap/store-buffer.cc

@@ -108,26 +108,6 @@ void StoreBuffer::StoreBufferOverflow(Isolate* isolate) {
 }
 
 
-void StoreBuffer::Uniq() {
-  // Remove adjacent duplicates and cells that do not point at new space.
-  Address previous = NULL;
-  Address* write = old_start_;
-  DCHECK(may_move_store_buffer_entries_);
-  for (Address* read = old_start_; read < old_top_; read++) {
-    Address current = *read;
-    if (current != previous) {
-      Object* object = reinterpret_cast<Object*>(
-          base::NoBarrier_Load(reinterpret_cast<base::AtomicWord*>(current)));
-      if (heap_->InNewSpace(object)) {
-        *write++ = current;
-      }
-    }
-    previous = current;
-  }
-  old_top_ = write;
-}
-
-
 bool StoreBuffer::SpaceAvailable(intptr_t space_needed) {
   return old_limit_ - old_top_ >= space_needed;
 }
@@ -247,20 +227,6 @@ void StoreBuffer::Filter(int flag) {
 }
 
 
-void StoreBuffer::SortUniq() {
-  Compact();
-  if (old_buffer_is_sorted_) return;
-  std::sort(old_start_, old_top_);
-  Uniq();
-
-  old_buffer_is_sorted_ = true;
-
-  // Filtering hash sets are inconsistent with the store buffer after this
-  // operation.
-  ClearFilteringHashSets();
-}
-
-
 bool StoreBuffer::PrepareForIteration() {
   Compact();
   PointerChunkIterator it(heap_);
@@ -285,41 +251,6 @@ bool StoreBuffer::PrepareForIteration() {
 }
 
 
-#ifdef DEBUG
-void StoreBuffer::Clean() {
-  ClearFilteringHashSets();
-  Uniq();  // Also removes things that no longer point to new space.
-  EnsureSpace(kStoreBufferSize / 2);
-}
-
-
-static Address* in_store_buffer_1_element_cache = NULL;
-
-
-bool StoreBuffer::CellIsInStoreBuffer(Address cell_address) {
-  if (!FLAG_enable_slow_asserts) return true;
-  if (in_store_buffer_1_element_cache != NULL &&
-      *in_store_buffer_1_element_cache == cell_address) {
-    return true;
-  }
-  Address* top = reinterpret_cast<Address*>(heap_->store_buffer_top());
-  for (Address* current = top - 1; current >= start_; current--) {
-    if (*current == cell_address) {
-      in_store_buffer_1_element_cache = current;
-      return true;
-    }
-  }
-  for (Address* current = old_top_ - 1; current >= old_start_; current--) {
-    if (*current == cell_address) {
-      in_store_buffer_1_element_cache = current;
-      return true;
-    }
-  }
-  return false;
-}
-#endif
-
-
 void StoreBuffer::ClearFilteringHashSets() {
   if (!hash_sets_are_empty_) {
     memset(reinterpret_cast<void*>(hash_set_1_), 0,

src/heap/store-buffer.h

@@ -83,21 +83,11 @@ class StoreBuffer {
   bool old_buffer_is_sorted() { return old_buffer_is_sorted_; }
   bool old_buffer_is_filtered() { return old_buffer_is_filtered_; }
 
-  // Goes through the store buffer removing pointers to things that have
-  // been promoted.  Rebuilds the store buffer completely if it overflowed.
-  void SortUniq();
-
   void EnsureSpace(intptr_t space_needed);
   void Verify();
 
   bool PrepareForIteration();
 
-#ifdef DEBUG
-  void Clean();
-  // Slow, for asserts only.
-  bool CellIsInStoreBuffer(Address cell);
-#endif
-
   void Filter(int flag);
 
   // Eliminates all stale store buffer entries from the store buffer, i.e.,
@@ -144,7 +134,6 @@ class StoreBuffer {
   void ClearFilteringHashSets();
 
   bool SpaceAvailable(intptr_t space_needed);
-  void Uniq();
   void ExemptPopularPages(int prime_sample_step, int threshold);
 
   void ProcessOldToNewSlot(Address slot_address,