Don't speed up your code, make it do less instead

I just read an extremely insightful blog post here. It's about speeding up your code, and the author makes an interesting point that he learned long ago from a mentor of his:

So there is no way, really, to make code go faster, because there is no way to
make instructions execute faster. There is only such a thing as making the
machine do less.

This is fscking brilliant advice. I never thought about code this way, but upon reflection I think he's absolutely correct. I can think of 1000 ways to accomplish this in both managed and unmanaged code, but ultimately it comes from knowing how your code is being built and what instructions are being created from it. As I think about some of the general principles of OO design (i.e. SOLID and such) I really am starting to see how efficient, extensible code improves this. Maybe the right thing to do in managed or unmanaged code when you start analyzing your code for performance is to actually look at the assembly or MSIL that is being generated instead of staring at it and trying to think of ways to optimize. Read the article and learn.