https://bugs.freedesktop.org/show_bug.cgi?id=89069
--- Comment #33 from Marek Olšák maraeo@gmail.com --- (In reply to Michel Dänzer from comment #32)
Sounds like it may be worth a shot to enable it again then.
I think unsafe-fp-math enables Abs and Neg source modifiers and other optimizations, so it's definitely worth it.