Really? Are you sure that really works? Those registers are not renamed and things could go wrong.
FPCR should be fine, as the manual requires you to surround it with EXCB (which is still serializing) if you want precise information.
rduniq/wruniq I'm less sure about... seems like it should be sufficient to only serialize wruniq though, since the only time you'll have problems with rduniq is if it gets reordered wrt a wruniq.