Hi @puddingfjz, we are working on Relax(Relay Next), which has first-class symbolic shape support. Here is a simple dynamic input shape example. Please check out the overview of Relax and our TVMCon talk for more information.
@ziheng has worked on dynamic-shape workload tuning: DietCode: Automatic Optimization for Dynamic Tensor Programs - TVMCon 2021.
@yongwww is working on supporting LSTM on Relax, and adding control flow support(e.g., closure, while_loop) to Relax.