LLC flags for -O3, or ideally a way to dump which are being used?

Hello,

I am trying to deduce the minimal LLC flags required for producing the equivalent of llc -O3 for my code.

I was hoping there was a way to dump all the flags and their parameters for a given llc -O3 run.

Does anyone know if there is a flag to dump these, or some other way to know which flags llc is using?

Thanks for considering this,
-Chad