Automatically generating instruction selectors using declarative machine descriptions

Abstract

Despite years of work on retargetable compilers, creating a good, reliable back end for an optimizing compiler still entails a lot of hard work. Moreover, a critical component of the back end---the instruction selector---must be written by a person who is expert in both the compiler's intermediate code and the target machine's instruction set. By generating the instruction selector from declarative machine descriptions we have (a) made it unnecessary for one person to be both a compiler expert and a machine expert, and (b) made creating an optimizing back end easier than ever before.