> I love that despite working with compilers for more than twenty years, they can still surprise and delight me.

This kind of optimization, complete loop removal and computing the final value for simple math loops, is at least 10 years old.

10 years is not a lot. Is almost “yesterday” things being done in a field 10 years old, can still surprise experts in the field. With 30+ years experience I still find relatively new things, that are maybe 15 yo.

In topics like compiler optimization, is not like there are many books which describe this kind of algorithms.

Learning something old can be surprising. Enjoying that learning can be delightful.

Seems like the author is both surprised and delighted with an optimization they learned of today. Surely you’ve been in the same situation before.