Intermediate representations in imperative compilers: A survey

Compilers commonly translate an input program into an intermediate representation (IR) before optimizing it and generating code. Over time there have been a number of different approaches to designing and implementing IRs. Different IRs have varying benefits and drawbacks. In this survey, we highlight key developments in the area of IR for imperative compilers, group them by a taxonomy and timeline, and comment on the divide between academic research and real-world compiler technology. We conclude that mainstream compilers, especially in the multicore era, could benefit from further IR innovations.