https://bugs.freedesktop.org/show_bug.cgi?id=71138
--- Comment #4 from yashax@windowslive.com --- (In reply to comment #3)
This looks like z-fighting issues. You might want to try disabling compiler backends via R600_DEBUG environment variable:
R600_DEBUG=nollvm R600_DEBUG=nosb R600_DEBUG=nollvm,nosb
The bug still exists with these environment variables. The bug report and my last tests were done with shader detail setting on low. I found that the bug happens with shader detail on low and medium, but on high and very high the bug disappears.