This is a good reminder that optimization without measurement is stupidity.

It’s also a reminder that compilers aren’t magic and optimizers aren’t all-knowing.

People have a tendency to ascribe magical properties to anything they don’t understand. Compilers and optimizers more so.

Measure before and after any optimization. You’d be surprised at what does and doesn’t improve efficiency.

Today’s CPUs are more complex than a human can understand.

Measure twice, cut once.