[littlestymaar]

But that's not something these kinds of tools are supposed do, even with trivial functions… These tools have no idea about the run-time (and there's no way they coule, since it depends on the load you put on the hardware in parallel of running your program)

[redjamjar]

I agree. There are tools though which are specifically for determining worst-case execution time for e.g. embedded systems which can actually give accurate timing information (upto a point).