unsigned int cell_base_start_index = Bitmap::IndexToCell(
Bitmap::CellAlignIndex(p->AddressToMarkbitIndex(cell_base)));
- // First check if the object is in the current cell.
+ // Check if the slot points to the start of an object. This can happen e.g.
+ // when we left trim a fixed array. Such slots are invalid and we can remove
+ // them.
+ if ((cells[start_index] & index_in_cell) != 0) {
+ return false;
+ }
+
+ // Check if the object is in the current cell.
MarkBit::CellType slot_mask;
if ((cells[start_index] == 0) ||
(base::bits::CountTrailingZeros32(cells[start_index]) >
// The object is in a preceding cell. Set the mask to find any object.
slot_mask = 0xffffffff;
} else {
+ // The object start is before the the slot index. Hence, in this case the
+ // slot index can not be at the beginning of the cell.
+ CHECK(index_in_cell > 1);
// We are interested in object mark bits right before the slot.
slot_mask = index_in_cell - 1;
}
MarkBit::CellType current_cell = cells[start_index];
- DCHECK(current_cell != 0);
+ CHECK(current_cell != 0);
// Find the last live object in the cell.
unsigned int leading_zeros =
base::bits::CountLeadingZeros32(current_cell & slot_mask);
- DCHECK(leading_zeros != 32);
+ CHECK(leading_zeros != 32);
unsigned int offset = Bitmap::kBitIndexMask - leading_zeros;
cell_base += (start_index - cell_base_start_index) * 32 * kPointerSize;
Address address = cell_base + offset * kPointerSize;
HeapObject* object = HeapObject::FromAddress(address);
- DCHECK(object->address() < reinterpret_cast<Address>(slot));
+ CHECK(object->address() < reinterpret_cast<Address>(slot));
if (object->address() <= slot &&
(object->address() + object->Size()) > slot) {
// If the slot is within the last found object in the cell, the slot is