Is there a way to benchmark/profile portably?

[Dukc]

Is there some way to measure the performance of a function so 
that the results will be same in different computers (all x86, 
but otherwise different processors)? I'm thinking of making a 
test suite that could find performance regressions automatically.

I figured out Bochs[1] could be used for that, but it seems an 
overkill for me to install a whole virtual operating system just 
to benchmark functions. Does anybody know more lightweight way?

[1] http://bochs.sourceforge.net/