https://bugs.freedesktop.org/show_bug.cgi?id=89069
--- Comment #28 from smoki smoki00790@gmail.com --- After http://cgit.freedesktop.org/mesa/mesa/commit/?id=c6d79ed289a75f13c65f011be87... which improve code quality i can enable unsafe-fp-math and grass is now there with trace from Comment 7
Daniel and others, you might want to recheck this.
I guess unsafe-fp-math might be reenabled now if is stabilise SI and of course because of better radeonsi performance.