There are many factors that determine the performance of a system. The choice of hardware can mean the difference between a few MIPS and a few hundred. Good data structures and algorithms are essential, and bookshelves have been written on this topic. Simple guidelines should also be followed to make sure that one’s code can be readily optimized. This paper describes some of the optimizations performed by today’s modern compilers that help to generate highly tuned code for maximum performance and minimal code size.