Agner Fog's optimization guide is worth a very close reading: https://www.agner.org/optimize/microarchitecture.pdf

If you want smaller chunks, Denis Bakhvalov is starting to hit his stride with a nice series of blog posts: https://easyperf.net/notes/

If that's not enough, Ingve (who submitted this) has made literally thousands of submissions, and a surprising number are excellent articles on optimization: https://news.ycombinator.com/submitted?id=ingve

Michael Abrash's Black Book is a classic.

http://www.jagregory.com/abrash-black-book/

It is a classic book and a great reference if you are optimizing for the 80386. But almost totally irrelevant for modern hardware. Its probably still a fun read for reminiscence purposes - Michael Abrash was a great writer.

It goes into pentium architectural points as well which is far more modern than 386. Built-in math coprocessors, Glorious! Though your point remains.

I am guilty of having a fair bit of nostalgia for this book. Memories of sitting in the back seat of my parents car in middle school. Pouring through this book. Fascinated by these inner secrets of machines I knew so little about at the time. Presented in a way even a 12 year old could mostly understand.

Are there any modern equivalents?