Well, truth be told, benchmarking isn't needed. the bitwise operator would be fastest
if (x & 1) /* In C of course */
because that's probably one of the quickest cpu instructions out there: AND AL, 0x1
Not surprisingly, that's already what if (%x & 1) in mIRC does-- which is further reason why an "iseven" isn't needed.. the addition would be purely for readability purpose..that doesn't sell me, anyway.