message: missing count_one optimisation
diff: @@ -94,13 +94,19 @@ impl SmallBitmap {
  unsafe { self.get_index_sparse_fast(b) }
  }
  - /// Get the position of a level index in the sparse array for insertion
  #[inline]
  - pub fn get_sparse_pos(&self, b: LevelIndex) -> ArrayIndex {
  + #[target_feature(enable = "popcnt")]
  + unsafe fn get_sparse_pos_fast(&self, b: LevelIndex) -> ArrayIndex {
  let mask = b.mask();
  ArrayIndex::create((self.0 & (mask - 1)).count_ones() as usize)
  }
  + /// Get the position of a level index in the sparse array for insertion
  + #[inline]
  + pub fn get_sparse_pos(&self, b: LevelIndex) -> ArrayIndex {
  + unsafe { self.get_sparse_pos_fast(b) }
  + }
  +
  /// Check if the element exist
  pub fn is_set(&self, b: LevelIndex) -> bool {
  (self.0 & b.mask()) != 0
  