Flow control is not always necessary. Other times it can be minimized. The point is not to never branch, but to avoid unnecessary ones.

It's not applicable to every situation, but one way to do this is some very basic fuzzy logic. You do a little math and then either choose a single branch at the end, or sometimes avoid a branch altogether. https://www.geeksforgeeks.org/artificial-intelligence/fuzzy-...

Another way to avoid some branches is to have specialized routines, maybe with multiple dispatch, rather than more general methods with a bunch of checks within them for slightly different situations.

A classic performance hack for critical sections is loop unrolling.