popFront causing more memory to be used

[ixid]

In any case with large values of k the branch prediction will be 
right almost all of the time, explaining why this form is faster 
than modulo as modulo is fairly slow while this is a correctly 
predicted branch doing an addition if it doesn't make it 
branchless. The branchless version gives the same time result as 
branched, is there a way to force that line not to optimized to 
compare the predicted version?