IL. Primary: What happens if you vote for one candidate but another candidate's pledged delegates? [View all]

For instance, you vote for Biden himself but you also vote for Warren's 5 delegates instead of Biden's.

I didn't do that today, but I've wondered for some time what that does to the delegate tally.
I asked on an 'Illinois for Warren' board but no one could come up with a confident answer.

Thanks.
Gidney N(o math for me, please, I was a Comm major) Cloyd