[RFC] Conv2D padding representation

Development RFC
12

So you suggested the following flow:

  1. Frontend converter generates conv2d (maybe 2-way or 4-way padding).
  2. relay.nn.conv2d legalizes the padding to 4-way.
  3. topi.nn.conv2d only accepts 4-way padding.

Due to the assertion in 3, AutoTVM conv2d workloads should always be 4-way padding. This solution seems promising to me.