https://bugs.freedesktop.org/show_bug.cgi?id=43332
--- Comment #2 from Stefano Teso stefano.teso@gmail.com 2011-12-15 09:37:46 PST ---
The bug is also present in the libGL 7.11.2 shipped by debian, so I don't think it's a regression or a bug in my config.
It looks like that inst->Dst[0].Register.WriteMask == 3 in tgsi_scs (), so the ZW components of the dest register are never written. Perhaps this could explain the artifact. Not that I'm a GL expert or anything ;-)