I liked the idea behind this post, but really the author fairly widely missed the mark in my opinion.

The extent to which you can "fool the optimizer" is highly dependent on the language and the code you're talking about. Python is a great example of a language that is devilishly hard to optimize for precisely because of the language semantics. C and C++ are entirely different examples with entirely different optimization issues, usually which have to do with pointers and references and what the compiler is allowed to infer.

The point? Don't just assume your compiler will magically make all your performance issues go away and produce optimal code. Maybe it will, maybe it won't.

As always, the main performance lessons should always be "1) Don't prematurely optimize", and "2) If you see perf issues, run profilers to try to definitively nail where the perf issue is".