FWIW, llvmpipe is greatly slower in compiling bigger shaders. As in from 200ms to 10s slower.
Probably worth mentioning that the corresponding time period (launch to glxgears) for the last major architectural change was a lot longer :
Originally Posted by phoronix
r600 - May 2007 to July 2009 (~26 months)
SI - Dec 2011 to July 2012 (~7 months)
The times are even shorter if you measure relative to cards people are likely to actually purchase for use with the open source drivers (Feb for 77xx, Mar for 78xx so 4-5 months rather than 7) but that's starting to get downright boring.
If part of the problem is that the community isn't doing enough to develop the driver, maybe AMD could give the new GPU's to driver devs to so that they can work on their drivers and test them. That way, they aren't only working on the drivers of the GPU's they currently own as well as encourage new development by people who want free stuff. It may be cheaper for AMD than hiring new people.