NIOS2IDE 9.1 questions

[Altera_Forum]

I recently upgraded from 7.2 to 9.1 and I have a fairly large C application. I am still trying to get comfortable with it.  

 In 7.2, depending on whether you build in debug or release, a directory of that name was created and the flash file was created and put in the appropriate directory. this seems to no longer be the case. is there a difference in the flash file between debug and release? Basic question, I know.... If I set compiler optimization to on, or 1-3, does that affect the debugger?   Probably, to answer all my questions, is there a cheat sheet on upgrading a project to 9.1? there appears to be a lot of verbage i dont understand....  thanks

[Altera_Forum]

gdb can usually debug code compiled at any optimisation level. 

At higher levels variables that only exist in registers may not be accessible by name, and static functions that are small, or only called once, will be inlined. If you ever need to look at the asm, the optimised code is often easier to follow because it contains less faffing. I would also always debug with the options you intent using in the release - otherwise you can get a sudden surprise!