  Many recent machine learning models show dynamic shape characteristics.
However, existing AI compiler optimization systems suffer a lot from problems
brought by dynamic shape models, including compilation overhead, memory usage,
optimization pipeline and deployment complexity. This paper provides a compiler
system to natively support optimization for dynamic shape workloads, named
DISC. DISC enriches a set of IR to form a fully dynamic shape representation.
It generates the runtime flow at compile time to support processing dynamic
shape based logic, which avoids the interpretation overhead at runtime and
enlarges the opportunity of host-device co-optimization. It addresses the
kernel fusion problem of dynamic shapes with shape propagation and constraints
collecting methods. This is the first work to demonstrate how to build an
end-to-end dynamic shape compiler based on MLIR infrastructure. Experiments
show that DISC achieves up to 3.3x speedup than TensorFlow/PyTorch, and 1.8x
than Nimble.
