The goalposts are constantly changing, but there are refactorings that achieve both.
As a student, real world performance analysis was one of the ways I kept myself engaged in otherwise sometimes tedious curricula. After college I landed a job far away from home only to discover their software was so slow I was embarrassed to be associated with it, so I got a quick self-directed study in practical optimization.
On any given day, you're much more likely to be amused by your own cleverness than anyone else is, so you either do it for your own reasons, stop doing it entirely, or find palatable forms of expression.
My most concrete example is probably the bizarre love triangle between locality of reference, lazy evaluation, and common subexpression elimination. There are several islands of sanity where reading comprehension is improved by refactoring in ways that happen to reduce or avoid calculations.
You clean up the code and it gets 5% faster. You use the same pattern in three places and you're comfortably into double digits.
As more evidence piled up for me about the dangers of confusing code, I spent more time thinking about the legibility and very little time thinking about the performance, but the fact is that I still do it intuitively. 25yo me would still be pretty happy with the performance of my code, even though <mumble>yo me gets a little concerned about that level of enthusiasm.
As a student, real world performance analysis was one of the ways I kept myself engaged in otherwise sometimes tedious curricula. After college I landed a job far away from home only to discover their software was so slow I was embarrassed to be associated with it, so I got a quick self-directed study in practical optimization.
On any given day, you're much more likely to be amused by your own cleverness than anyone else is, so you either do it for your own reasons, stop doing it entirely, or find palatable forms of expression.
My most concrete example is probably the bizarre love triangle between locality of reference, lazy evaluation, and common subexpression elimination. There are several islands of sanity where reading comprehension is improved by refactoring in ways that happen to reduce or avoid calculations.
You clean up the code and it gets 5% faster. You use the same pattern in three places and you're comfortably into double digits.
As more evidence piled up for me about the dangers of confusing code, I spent more time thinking about the legibility and very little time thinking about the performance, but the fact is that I still do it intuitively. 25yo me would still be pretty happy with the performance of my code, even though <mumble>yo me gets a little concerned about that level of enthusiasm.