[llvm] How to run a simple Machine Function Pass

Hi all,

I’m trying to run a MachineFunction Pass, but it seems running that is more complicated that running a frontend pass. llvm 3.4 official document [http://llvm.org/docs/WritingAnLLVMPass.html] only describes writing/running a front end pass, while running backend passes are completely different. So, it would be very helpful if someone explains, how one can run a backend pass step by step.