Abstract
Many fields of study in compilers give rise to the concept of a join point — a place where different execution paths come together. While they have often been treated by representing them as functions or continuations, we believe it is time to study them in their own right. We show that adding them to a direct-style functional intermediate language allows new optimizations to be performed, including a functional version of loop-invariant code motion. Finally, we report on recent work on the Glasgow Haskell Compiler which added join points to the Core language.