On Don, 2012-09-06 at 09:45 -0400, Tom Stellard wrote: > On Thu, Sep 06, 2012 at 01:00:01PM +0200, Michel Dänzer wrote: > > From: Michel Dänzer <michel.daen...@amd.com> > > I'm still not quite sure what the intended use cases are for adding > implicit uses and defs to instructions. I tried to do this with the VCC > register for VOPC and the V_CNDMASK instructions, but the optimizer > was incorrectly marking some instructions dead. It's possible there was > something else I was doing that was wrong, but in any case I think we > should keep an eye on this for potential bugs.
Yeah, I was hitting similar issues trying to only enable WQM for the parts where it's really needed. I suspect the problem is that implicit uses and defs only reference the physical registers, whereas the optimizer only tracks dependencies between values. But I have no idea yet how that could be addressed in order to e.g. prevent vector instructions from being moved beyond changes to the EXEC register. > Either way, this change won't hurt anything. Right, although this does seem to at least prevent the enabling of WQM from being considered dead and removed. > Reviewed-by: Tom Stellard <thomas.stell...@amd.com> Thanks! -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Debian, X and DRI developer _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev