Function num_splits 

pub fn num_splits(
    policy: SplitkPolicy,
    sm_count: u32,
    num_q_heads: u32,
    legacy_ref_seqs: u32,
) -> u32

2026-09-25: The split count for a launch.

legacy_ref_seqs is read by SplitkPolicy::Legacy only; the other arms do not depend on the batch, which the_auto_split_count_does_not_move_with_the_co_batched_count tests.