[Bug] [Relay] Error when compiling a simple ONNX model

[luyaor]

Description

When compiling following model with TVM, it will error.

The model(with ONNX as frontend) with error is as follows, check bug.onnx in bug2.zip.

Error Log

The Relay type checker is unable to show the following types match.
In particular dimension 0 conflicts: 3 does not match 1.
The Relay type checker is unable to show the following types match.
In particular `Tensor[(3), float32]` does not match `Tensor[(1), float32]`
note: run with `TVM_BACKTRACE=1` environment variable to display a backtrace.

How to reproduce

Environment

Python3, with tvm, onnx, you could also use Conda as conda env create -f environment.yml

tvm version: c31e338 Wed Dec 9 14:52:58 2020 +0900

1. Download bug2.zip

2. Run python check.py.

[jwfromm]

Thanks for finding this bug, it's due to a bad assumption made in Prelu conversion about the input layout. The issue is fixed in #7208 and I've confirmed the test script works with that change.