https://bugs.freedesktop.org/show_bug.cgi?id=35257
--- Comment #7 from Tom Stellard <tstellar at gmail.com> 2011-03-14 17:28:24 PDT --- (In reply to comment #5) > (In reply to comment #4) > > Like Marek said, this isn't a bug it is a hardware limitation. The only way > > this could work is with changes to Gnome Shell, so you should contact the > > Gnome > > Shell developers, although they might tell your hardware is unsupported. > > Since we know there's a lot of work still to be done in the compiler's higher > level optimization passes, I always feel like this is a bit of a cop out > answer. The TGSI input is 125 instructions, and it looks like a nightmare of > lowered if-statements. There are way more CMP/SEQ/MUL sequences than any > program should generate. Unsurprisingly, the driver chokes on it. I'm sure > the i915 driver, which has limitations similar to r300, would choke even > worse. > > Comparing the GLSL to the generated TGSI might reveal some high-level > optimization opportunities that we're missing. It may also help us give some > suggestions to the gnome-shell folks to make the shader more friendly to older > hardware. There are, after all, a lot of i915s and r300s out there. > > Just for giggles, could we get the output of MESA_GLSL=dump too? Use the same > procedure as for RADEON_DEBUG=fp. We were able to give some suggestions to the gnome shell developers to get the shader to fit. The optimization that is missing is pre-computing of equivalent expressions (not sure what the technical term is). In this shader there was a four clause conditional that was being used in two different IF statements. I've attached the before and after versions of the shader if you're interested -- Configure bugmail: https://bugs.freedesktop.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the assignee for the bug.
