Graph IRs for Impure Higher-Order Languages: Making Aggressive Optimizations Affordable - OOPSLA 2023

Explore a groundbreaking 18-minute video presentation from OOPSLA2 2023 that introduces a novel graph-based intermediate representation (IR) for compiler optimizations in impure higher-order languages. Discover how this innovative approach combines reachability types with an expressive effect system to compute precise effect dependencies, enabling aggressive global optimizations while supporting local reasoning and separate compilation. Learn about the formalization of this new graph IR based on a λ-calculus with a reachability type-and-effect system and its application in various performance case studies, including tensor loop fusion, CUDA kernel fusion, symbolic execution of LLVM IR, and SQL query compilation. Gain insights into the significant speedups of up to 21x observed in the Scala LMS compiler framework using this new graph IR.