[heap] Add optimized RecordWrites

BUG=

Review URL: https://codereview.chromium.org/1834373003

Cr-Commit-Position: refs/heads/master@{#35231}

src/elements.cc

@@ -1011,13 +1011,10 @@ class ElementsAccessorBase : public ElementsAccessor {
                        &array_length) &&
                    array_length <= Smi::kMaxValue)) {
         // Since we use std::sort above, the GC will no longer know where the
-        // HeapNumbers are, hence we have to write them again.
-        // For Arrays with valid Smi length, we are sure to have no HeapNumber
-        // indices and thus we can skip this step.
-        for (uint32_t i = 0; i < nof_indices; i++) {
-          Object* index = combined_keys->get(i);
-          combined_keys->set(i, index);
-        }
+        // HeapNumbers are.  For Arrays with valid Smi length, we are sure to
+        // have no HeapNumber indices and thus we can skip this step.
+        FIXED_ARRAY_ELEMENTS_WRITE_BARRIER(isolate->heap(), *combined_keys, 0,
+                                           nof_indices);
       }
     }
 

src/heap/heap-inl.h

@@ -399,9 +399,20 @@ void Heap::RecordWrite(Object* object, int offset, Object* o) {
   if (!InNewSpace(o) || !object->IsHeapObject() || InNewSpace(object)) {
     return;
   }
-  Page* page = Page::FromAddress(reinterpret_cast<Address>(object));
-  Address slot = HeapObject::cast(object)->address() + offset;
-  RememberedSet<OLD_TO_NEW>::Insert(page, slot);
+  RememberedSet<OLD_TO_NEW>::Insert(
+      Page::FromAddress(reinterpret_cast<Address>(object)),
+      HeapObject::cast(object)->address() + offset);
+}
+
+void Heap::RecordFixedArrayElements(FixedArray* array, int offset, int length) {
+  if (InNewSpace(array)) return;
+  Page* page = Page::FromAddress(reinterpret_cast<Address>(array));
+  for (int i = 0; i < length; i++) {
+    if (!InNewSpace(array->get(i))) continue;
+    RememberedSet<OLD_TO_NEW>::Insert(
+        page,
+        reinterpret_cast<Address>(array->RawFieldOfElementAt(offset + i)));
+  }
 }
 
 

src/heap/heap.cc

@@ -1111,13 +1111,7 @@ void Heap::MoveElements(FixedArray* array, int dst_index, int src_index,
   DCHECK(array->map() != fixed_cow_array_map());
   Object** dst_objects = array->data_start() + dst_index;
   MemMove(dst_objects, array->data_start() + src_index, len * kPointerSize);
-  if (!InNewSpace(array)) {
-    for (int i = 0; i < len; i++) {
-      RecordWrite(array, array->OffsetOfElementAt(dst_index + i),
-                  dst_objects[i]);
-    }
-  }
-  incremental_marking()->IterateBlackObject(array);
+  FIXED_ARRAY_ELEMENTS_WRITE_BARRIER(this, array, dst_index, src_index);
 }
 
 

src/heap/heap.h

@@ -1084,6 +1084,8 @@ class Heap {
 
   // Write barrier support for object[offset] = o;
   inline void RecordWrite(Object* object, int offset, Object* o);
+  inline void RecordFixedArrayElements(FixedArray* array, int offset,
+                                       int length);
 
   Address* store_buffer_top_address() { return store_buffer()->top_address(); }
 

src/objects-inl.h

@@ -1149,6 +1149,12 @@ MaybeHandle<Object> JSReceiver::GetProperty(Isolate* isolate,
       object, HeapObject::RawField(object, offset), value); \
   heap->RecordWrite(object, offset, value);
 
+#define FIXED_ARRAY_ELEMENTS_WRITE_BARRIER(heap, array, start, length) \
+  do {                                                                 \
+    heap->RecordFixedArrayElements(array, start, length);              \
+    heap->incremental_marking()->IterateBlackObject(array);            \
+  } while (false)
+
 #define CONDITIONAL_WRITE_BARRIER(heap, object, offset, value, mode) \
   if (mode != SKIP_WRITE_BARRIER) {                                  \
     if (mode == UPDATE_WRITE_BARRIER) {                              \