https://bugs.freedesktop.org/show_bug.cgi?id=73320
--- Comment #46 from farmboy0+freedesktop@googlemail.com --- (In reply to comment #45)
Thank you very much for your help farmboy0. I was able to build and run everything as you mentioned. First of all, my systems doesn't hang as you describe in Comment 21, all the games are (kind of) running. I tested master branch of llvm as well as http://cgit.freedesktop.org/~tstellar/llvm/log/?h=si-spill-fixes-v3. Both versions don't crash anymore, but the performance is very bad. With master branch the games are stuttering heavily, every 2-3 seconds the application stops for a second. With the si-spill-fixes-v3 everything's running a bit smoother, but still very slowly. Feels like similar behavior in both cases, but using si-spill-fixes-v3 it feels like the games would "wait" for shorter period of time, therefor more often. I tested with both 64 and 32 bit builds.
You need to realize though that the error message of llvm running out of registers is caused by two seperate issues.
The first issue is caused by errors with the SGPR spilling in llvm 3.4, this one is fixed with llvm git or with Tom's si-spilling-fixes branch.
The second issue is recorded in https://bugs.freedesktop.org/show_bug.cgi?id=75276 and is not yet fixed as (at least for me) it causes crashes.
You can differentiate the two issues while using llvm git. If while running your app you see messages in the console to the effect of VGPR spilling not being supported your app is hit by issue number two. You should then try to run this app with Tom's si-spill-fixes-v3 branch which started to try to implement VGPR spilling if i interpret the change messages correctly.