FreeTensor: a free-form DSL with holistic optimizations for irregular tensor programs

Tensor programs are of critical use in many domains. Existing frameworks, such as PyTorch, TensorFlow, and JAX, adopt operator-based programming to ease programming, increase performance, and perform automatic differentiation. However, as the rapid development of tensor programs, operator-based programming shows significant limitations for irregular patterns since a large amount of redundant computation or memory access is introduced. In this work, we propose FreeTensor, a free-form domain specific language which supports redundancy-avoid programming by introducing fine-grained control flow. With optimizations including partial evaluation, dependence-aware transformations, and fine-grained automatic differentiation, FreeTensor is able to generate high performance tensor programs on both CPU and GPU. Experiments show a speedup over existing tensor programming frameworks up to 5.10 × (2.08 × on average) without differentiation, and up to 127.74 × (36.26 × on average) after differentiation, for typical irregular tensor programs.