[mhh__]

You're fighting a losing battle though. You can guess what shape the assembly looks like but ultimately unless you have measured and identified somewhere where you can make progress your brain simply cannot keep in mind all the little nuances of the optimizations a compiler does.

It's worth adding that the compilers themselves aren't perfect - you can use LLVM's code to try and predict how your loop will perform (LLVM-MCA) and last time I checked it wasn't amazingly accurate.