I spend most of my time writing C for embedded systems. You should focus first on making life easy for the people reading your code. Use `% 2` and `* 4` when those are the things you mean, rather than `& 1` and `<< 2`. Compilers have been able to do those strength reductions on their own for years, and in most cases even if the compiler didn't, the cycles you'd save aren't worth it.