https://bugs.freedesktop.org/show_bug.cgi?id=73110
--- Comment #4 from Marek Olšák maraeo@gmail.com --- The shaders are generated by this code:
http://cgit.freedesktop.org/mesa/mesa/diff/src/gallium/auxiliary/util/u_simp... http://cgit.freedesktop.org/mesa/mesa/diff/src/gallium/auxiliary/util/u_simp...
There is nothing special except for the texel fetch instructions which read from MSAA textures. The shaders also contain float<->int and float<->unsigned conversions. I think the latter is not used with GLSL very often.