about ARM microprocessor
Well, for one thing the ARM compiler generates code that can be used in an ARM microcontroller, the Tasking compiler for ARM does (to my best knowledge) not exist. The compiler you use needs to support your target device, e.g. LPC2292, an ARM microcontroller versus C167CR, an Infineon microcontroller supported by Tasking.
Compiler internals such as optimization levels, multipass linking and so on are probably not the kinds of information you were looking for.
Cheers, Bob