> Pike's rules 1 and 2 restate Tony Hoare's famous maxim "Premature optimization is the root of all evil."
Looks like wrongly attributed to Hoare? That famous quote is by Knuth
Looks like wrongly attributed to Hoare? That famous quote is by Knuth
"We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil. Yet we should not pass up our opportunities in that critical 3%."
1. It is only ever about small efficiencies.
2. And about small efficiencies in the 97% non-critical parts
So:
1. It is always valid to concern yourself with large efficiencies.
2. In the critical 3%, it is also legitimate to worry about small efficiencies.
For context, later in the same paper (Structured Programming with goto statements):
“The conventional wisdom [..] calls for ignoring efficiency in the small; but I believe this is simply an overreaction [..] In established engineering disciplines a 12% improvement, easily obtained, is never considered marginal; and I believe the same viewpoint should prevail in software engineering."
So his actual message is pretty much the opposite of what is attributed to him.