The Mature Optimization Handbook

The trickiest part of speeding up a program is not doing it, but deciding whether it’s worth doing at all. There are few clear principles, only rules of thumb.

Part of the problem is that optimization is hard to do well. It’s frighteningly easy to devolve into superstitious ritual and rationalization. Then again, there can be big payoffs hidden in surprising places. That’s why expert advice about performance tends to have a gnomic, self-contradictory flavor: “If you don’t know what you are doing, don’t do it! You’ll know if you know what you are doing. And remember to design your programs for performance.” The experts are acutely worried about encouraging more folly, yet can’t quite bring themselves to ignore the possible gains.