Under what conditions, if any, will (current versions of) ifort assume associativity of arithmatic when working with floating point variables, and optimize away corrections such as those found in the Kahan summation algorithm: ( http://en.wikipedia.org/wiki/Compensated_summation )
i.e. Does the compiler assume associativity of arithmatic by default? When -O3 is passed? Is there a way to turn it off, if it's on?