That's not a fair reading. I don't see anywhere that the article makes a any suggestion about when to optimize, it only suggests techniques that you could presumably use when you actually need to. Just as it's silly to prematurely optimize, it's silly to toss these suggestions out the window. If you hit a point where you need to optimize, these suggestions can be very useful.
> You're also fighting JIT assumptions, since all VM devs will attempt to optimize against common patterns
Optimization nearly always means that you're optimizing against a particular implementation, which may not be the same in the future. But your app lives today, in today's world. If you actually do hit a bottleneck, should you throw up your hands and say, "Don't worry, I'm sure it won't matter in a few years?" Of course not. Just as you shouldn't prematurely optimize, you should be willing to do it when necessary. Having some knowledge about what might work is definitely helpful.
In fairness, unless you only care about Chrome, there are many implementations already. Many of these types of optimizations do not necessarily have a net positive effect on performance across the board.
>That's not a fair reading. I don't see anywhere that the article makes a any suggestion about when to optimize, it only suggests techniques that you could presumably use when you actually need to.
Then you don't have a fair reading of my comment. I didn't say to never use it. There may be time-sensitive areas that perform a lot of work, very often. In those cases, go nuts, squeeze out every ms per frame you can. In the vast majority of cases, don't bother. Focus on maintainability and architecture and choose the right data structures (that's where your bottlenecks are going to be). Don't bother with low level details.
> You're also fighting JIT assumptions, since all VM devs will attempt to optimize against common patterns
Optimization nearly always means that you're optimizing against a particular implementation, which may not be the same in the future. But your app lives today, in today's world. If you actually do hit a bottleneck, should you throw up your hands and say, "Don't worry, I'm sure it won't matter in a few years?" Of course not. Just as you shouldn't prematurely optimize, you should be willing to do it when necessary. Having some knowledge about what might work is definitely helpful.