[almostgotcaught]

I wish people would stop saying this. It's like CS-woo the idea that some magical solution exists that saves you from having to think real hard about the hardware, that magical abstractions save the day.

All of these things boil down to combinatorial optimization problems (bin packing ring a bell?). And there are no widely available compilers or JITs or whatever that bundle ILP solvers. Thus, what you're really getting with every compiler is a heuristic/approximate solution (to many many combinatorial optimization problems). Decide for yourself whether you're comfortable with your code just being approximately good or if you need to actually understand how your system works.