Code Factoring in GCC

Though compilers usually focus on optimizing for performance, the size of the generated code has only received attention recently. On gen-eral desktop systems the code size is not the biggest concern, but on devices with a limited storage capacity compilers should strive for as small a code as possible. GCC already con-tains some very useful algorithms for optimiz-ing code size, but code factoring – a very pow-erful approach to reducing code size – has not been implemented yet in GCC. In this paper we will provide an overview of the possibilities of using code factoring in GCC. Two code fac-toring algorithms have been implemented so far. These algorithms, using CSiBE as a bench-mark, produced a maximum of 27 % in code size reduction and an average of 3%.