I looked through the "About CodeWarrior Development Studio" installation log, and found a line that says "C/C++ Development Tools" provided by Eclipse CDT. That's the closest thing I can find to any compiler identification.
EDIT:
I also notice that I have a gnu subdirectory in my CodeWarrior directory, so...maybe my compiler's mingw?
EDIT II:
Aha! I just built an example project, and the console window has several lines:
'Invoking: ARM Ltd Windows GCC C Compiler'
So...how to alter optimization values? They're definitely not set for debugging.
Thanks.