Comment by friendly_chap
12 years ago
I think we can agree that having that level of control is unnecessary for most programming tasks. In fields where it matters, fine. Otherwise I let the compiler do it's job, probably they will get better/are already better at it than me. I don't trust humans, including myself. My compiler never made a bad decision so far because it woke up with a hangover/in a bad mood.
Your compiler has no idea about whether data structure A will perform 100 times faster than data structure B because B is scattered all over memory and incurs a page fault on every reference and A has locality of reference.
No compiler optimization is going to get you a 100 to 1 improvement with a conventional language, but choosing the right data structure and algorithm for a task certainly can.