Is there any way to do constant foldering for relax Expr?


In the old times, there is fold_constant call in relay, so that we could fold a complex constant expr into constant value.

Take pad for example, this op’s pad value seq is different in torch and onnx. So when torch export to onnx, it would create a subgraph to convert into the sequence required by onnx.

In relay, we could easily call fold_constant this subgraph into a constant, but in relax, seems we cannot do this easily?