C++ performance tips and rules of thumb anyone?

When coding, what is a good rule of thumb to keep in mind with respect to performance? There are endless ways to optimize for a specific platform and compiler, but I'm looking for answers that apply equally well (or almost) across compilers and platforms.


A famous quote come to mind:

"We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil." (Knuth, Donald. Structured Programming with go to Statements, ACM Journal Computing Surveys, Vol 6, No. 4, Dec. 1974. p.268.)

But maybe you should not pass large data structures by value anyway... :-)

Edit: And maybe also avoid O(N^2) or more complex algorithms...

Need Your Help

Detect orientation using javascript on android devices

java javascript android

Using some code from this question I have set up some code to detect when an android device is rotated. It works great for the asus tablet (4.0.3) and two simulators (4.0.3 and 2.1), but for the ki...

About UNIX Resources Network

Original, collect and organize Developers related documents, information and materials, contains jQuery, Html, CSS, MySQL, .NET, ASP.NET, SQL, objective-c, iPhone, Ruby on Rails, C, SQL Server, Ruby, Arrays, Regex, ASP.NET MVC, WPF, XML, Ajax, DataBase, and so on.