You can run a simulator and run code benchmarks on the simulator. Or run code on an eval board with a comparable processor and do benchmarks there.
I don't know what OpenCV and LADAR are, but I assume you're compiling the code yourself, so you should use the same compiler you'll be using for the target processor.
Even if it appears to run, you really want to know how much margin you have so some tiny change won't break the code. If you have access only to an eval board it's possible to do crude things like toggle an output pin when the processor is idle, in which case the average output voltage can be used to roughly determine how much of the processor bandwidth is still available.