The LLVM-based Flang project is actively developing a standards-compliant compiler for Fortran—the world’s first high-level programming language and still an important language for science and engineering today. While Fortran’s core strength of writing computations on arrays remains, the standard language continues to add new facilities such as object-oriented programming. The Flang project has been exploring the use of MLIR, specifically the definition of Flang’s Fortran IR (FIR) as a framework upon which to build a more comprehensive and regular set of optimizations for both better performance and overall reliability of Flang. This talk will explore what the FIR dialect is, how it is built upon and uses other aspects of MLIR, as well as some of the high-level optimizations achieved.
