XIL and YIL: the intermediate languages of TOBEY

Abstract

Typically, the choice of intermediate representation by a particular compiler implementation seeks to address a specific goal. The intermediate language of the TOBEY compilers, XIL, was initially chosen to facilitate the production of highly optimal scalar code, yet, it was easily extended to a higher level form YIL in order to support a new suite of optimizations which in most existing compilers are done at the level of source to source translation. In this paper we will discuss those design features of XIL that were important factors in the production of optimal scalar code. In addition we will demonstrate how the strength of the YIL abstraction lay in its ability to access the underlying low level representation.