ABSTRACT
The topic of scalar compiler optimizations is definitely not new. It has been studied, researched and criticized for over 40 years. Several books [3, 7, 8, 41, 44] and articles contain detailed descriptions of important optimizations that are performed by compilers. However, the last word has not yet been said on this topic. The emergence of newer intermediate forms and extremely sophisticated microprocessors have always managed to keep the subject alive. Some of the important classical optimization algorithms have been made simpler, more precise and more efficient due to the emergence of the static single assignment (SSA) form as an important intermediate representation used in compilers [9]. In this chapter we present some of the important optimization algorithms as applied to the traditional flow graph and the SSA form. We hope that this helps in gaining an insight into the working of SSA-based algorithms.
