Ebook: Writing efficient programs

Bentley has the right idea when he states that you first write a correct, understandable and maintainable program, and then if it is not fast enough, modify it to improve the efficiency. He is also correct in pointing out that with this approach, modifications to improve efficiency, while not altering the correctness of the program, tend to reduce the clarity and maintainability of the code. However, he does miss one important point, which in his defense, is to a large extent due to the date of original publication.With the availability of modern tools and advances in software design, it is now possible to create programs where the efficiency of the code can be part of the design. Changes in the design made to improve the efficiency can increase the maintainability and reduces the need for final alterations that lower the clarity and portability.