https://bugs.freedesktop.org/show_bug.cgi?id=53511
--- Comment #1 from almos aaalmosss@gmail.com 2012-09-07 18:05:39 UTC --- I see that testing is the first item on the r600todo list, and to see if there are any differences between the two shader compilers. Maybe this should be a prerequisite of that, because most of the shader-heavy applications hit this fallback.
BTW I don't see any performance difference between the two compilers on my hd6850 apart from what I reported in bug 51787