There is a good book (books) to read if you can find them. The author, Jon Bently, has written a large number of articles on optimizing C programs.

Somce of these books are certainly out of print. However, they are extremely good.

1. "Writing Efficient Programs", Jon Louis Bently, Prentice-Hall, ISBN 0-13-970251-2 or 0-13-970244-X.

2. "Programming Pearls", Jon Bently, Addison-Wesley, ISBN 0-201-10331-1.

3. "More Programming Pearls", Jon Bently, Addison-Wesley, ISBN 0-201-11889-0.

4. "Programming Pearls, 2nd ed", Jon Bently, Addison-Wesley, ISBN 0-201-65788-0.

Enjoy,

Jon