No, even then you're doing it wrong. Either: your compiler should optimize it properly and you shouldn't be worrying about it, or you shouldn't be doing it in

No, even then you're doing it wrong. Either: your compiler should optimize it properly and you shouldn't be worrying about it, or you shouldn't be doing it in C anyway. If the difference between the two is actually important, then chances are your compiler is doing a myriad of other things significantly sub-optimally as well. Most likely far more sub-optimally than the difference between either of those.