I've heard many variations of the above, and the solution to almost all of them is loop versioning as appropriate to the particular case. In this case, a single

I've heard many variations of the above, and the solution to almost all of them is loop versioning as appropriate to the particular case. In this case, a single check before the loop would suffice, and then that 6% disappears. The battle can't be won because of a perspective difference. It's really difficult to communicate the importance of a sane programming model when a sane programming model has not been a priority for C or C++ since their respective inceptions. They've prioritized low-level manipulations and performance over everything else and ironically painted themselves into silly corners like this one; even when you want the hardware instruction that does signed two's complement arithmetic, you can't get it, because the other firmly-held belief that compilers are never wrong.