assertLockHeld(p.mheapLock)

	// If the searchAddr refers to a region which has a higher address than
	// any known chunk, then we know we're out of memory.
	if chunkIndex(p.searchAddr.addr()) >= p.end {
		return pageCache{}
	}
	c := pageCache{}
	ci := chunkIndex(p.searchAddr.addr()) // chunk index
	var chunk *pallocData
	if p.summary[len(p.summary)-1][ci] != 0 {
		// Fast path: there's free pages at or near the searchAddr address.

	// because it comes from the OS, so it's sufficient to align the
	// index.
	haveMin := s.min.Load()
	haveMax := s.max.Load()
	needMin := alignDown(uintptr(chunkIndex(base)), physPageSize/scSize)
	needMax := alignUp(uintptr(chunkIndex(limit)), physPageSize/scSize)

	// We need a contiguous range, so extend the range if there's no overlap.
	if needMax < haveMin {
		needMax = haveMin
	}

  Type new_element_type =
      IntegerType::get(attr.getContext(), storage_bit_width_);
  return attr.mapValues(new_element_type, [&](const APFloat &old) {
    int chunk_index = flatten_index / chunk_size;
    flatten_index++;
    return converters[chunk_index % dim_size].quantizeFloatToInt(old);
  });
}