Hi David, It's certainly possible, but it's going to take some work. My random idea would be to change how all the branch instructions are defined, so the stash their real target address somewhere and jump to your handler. Other than that manually instrumenting the program (or doing it with some compiler modifications) would probably be your best bet. While it doesn't take any time to switch thread contexts, by definition the context has all the state from the thread in it, so I'm not sure how switching would solve your problem.
Ali On Mar 24, 2013, at 11:18 PM, David Gloe <gloex...@umn.edu> wrote: > Hello, > > I am attempting to instrument branch instructions in a program in gem5. So > far, I have code in AtomicSimpleCPU which determines when branch instructions > are executed. For every branch, I would like to call an instrumentation > function and then return to execution of the simulated program. This would be > fairly simple, but I would like to execute the instrumentation function > within the simulator, so the instrumentation time is taken into account on > the simulator statistics. > > Is it possible to do something like this? Any ideas on how to do this? The > function could be compiled in with the program, so we might be able to > instrument by manually setting up arguments and changing the PC to the > instrumentation function. Another idea I had would be to have two thread > contexts for one CPU with one running the application and one doing > instrumentation, and switching between them as needed. Is this sort of thing > possible; is there any simulation time used by thread context switches? > > Thanks, > David G. > > -- > David Gloe > gloex...@umn.edu da...@cs.umn.edu dcg...@gmail.com > Masters Student, Computer Science > University of Minnesota > > _______________________________________________ > gem5-users mailing list > gem5-users@gem5.org > http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users > _______________________________________________ gem5-users mailing list gem5-users@gem5.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
