EuroLLVM

MultiLevel Tactics: Lifting loops in MLIR

We propose MultiLevel Tactics, or ML Tactics for short, an extension to MLIR that recognizes high-level abstractions patterns (e.g., linear algebra operations) in low-level dialects and replaces them with the corresponding operations of an appropriate high-level dialect. Our current prototype recognizes matrix multiplications in loop nests of the Affine dialect and lifts these to the Linalg dialect. The pattern recognition and replacement scheme are designed as reusable building blocks for transformations between arbitrary dialects and can recognize commonly recurrent patterns in HPC applications.