I am ok with either solution as long as it fixes <a href="https://bugs.freedesktop.org/show_bug.cgi?id=31827">Bug 31827</a>. I have tested my patch and it works. There was a bug in lower_jumps that made discard statements with a condition be treated as without it, causing the removal of all instructions after discard. This code from my patch fixes it: --- a/src/glsl/lower_jumps.cpp +++ b/src/glsl/lower_jumps.cpp @@ -202,7 +202,9 @@ struct ir_lower_jumps_visitor : public ir_control_flow_visitor { virtual void visit(class ir_discard * ir) { - truncate_after_instruction(ir); <div id=":au"> + if (!ir->condition) { + truncate_after_instruction(ir); + } this->block.min_strength = strength_discard; } </div> Marek <div class="gmail_quote">On Thu, Nov 25, 2010 at 12:40 PM, Kenneth Graunke <<a href="mailto:kenneth@whitecape.org">kenneth@whitecape.org</a>> wrote: <blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> I was actually working on the same thing today, and wrote two passes for dealing with discards. I was just looking into adding ir_to_mesa and brw_fs support when I saw your patch, so I just split that out and reused it. Thanks for writing that! I'm not sure whether doing it in a separate pass (like I've done) or in lower_if_to_cond_assign is better. Also, I haven't been able to properly test any of this yet since I don't yet have brw_fs support. It may be completely broken, but I wanted to put it out there anyway so people know there are two possible solutions. _______________________________________________ mesa-dev mailing list <a href="mailto:mesa-dev@lists.freedesktop.org">mesa-dev@lists.freedesktop.org</a> <a href="http://lists.freedesktop.org/mailman/listinfo/mesa-dev" target="_blank">http://lists.freedesktop.org/mailman/listinfo/mesa-dev</a> </blockquote></div>