Currently developing a GameBoy emulator and would love to be able to run at 60 FPS in debug mode, is it feasible?
Hey everyone! First of all, here's the source code for the emulator along with the output of cargo flamegraph
https://github.com/nicolas-siplis/feboy
Sorry for the huge image, haven't figured out a way for the graph to show the full name for function calls and this was the only thing I could think of.
If I'm reading the output correctly, it looks like my most of my time is spent in the InterruptHandler::get\_state and InstructionFetcher::fetch\_instruction functions.
I'm super puzzled as to how I could improve the performance of the former because it's actually not that much logic. For the latter I guess it makes sense that it's taking such a significant amount of time since it's basically a gigantic match statement.
I was also surprised as to how much removing HashMap from the InstructionHandler made a difference, since playing in debug mode went from being simply impossible (less than 5FPS would be my guess) to "only" a really miserable experience (at least 10 FPS).