So there's this classic trick: bool isPowerOf2(uint x) { return (x & (x - 1)) == 0; }which has no branches at least with dmd, see http://goo.gl/TVkCwc.Any ideas for faster code?
If you dont mind asm then after you do... tmp = x-1;you could add the borrow/carry flag back onto the tmp, so it'd add back up to zero any time there's an underflow in the (x-1) op.
So two extra instructions, (you need a zero for the ADC) no branch.
