def get_register_count(num_blocks, num_threads):
    """
    Returns the number of registers available per block for sm_20

    Parameters
    ----------
    num_blocks : int
        The number of blocks to target per kernel launch
    num_threads : int
        The number of threads to target per kernel launch
    """
    return max(min(32768 / num_blocks / num_threads, 63), 1)
