er (indices=1)
                             /                  |
                            /                  Add (optional, B=0)
                           /                    |
                        Gather (segment_ids) Unsqueeze (axes=0)
                           \        |           |
                            \     Gather      Slice (data[1,512], starts=0, ends=*, axes=1, steps=1)
                              \    /            |
                                Add          Gather
                                   \       /
                                      Add
                                       |
                                LayerNormalization
        