Padding in the MaxPool operator is not working

[owulveryck]

I am trying to make the test of the Maxpool with padding to turn green (Line 169 of the file maxpool_autogenerated_test.go).

The test consists of an input tensor with shape (1, 3, 28, 28) of float32;
The kernel shape is (3,3) and the strides are set to their default values (1).
The padding given to the model is []int{2,2,2,2}, which has to be converted into a two dimensional []int for the Maxpool operator of Gorgonia. (the doc from onnx is here)

The expected shape of the output tensor is (1,3,30,30).

The problem is that no padding allows me to get this shape (I have tried manually to set the shape in the maxpool_wip.go file like this:

Here is the test I run from the batchnorm branch of this repo

$ cd operator
$ go test -run=TestMaxpool_2d_pads
--- FAIL: TestMaxpool_2d_pads (0.00s)
    maxpool_autogenerated_test.go:222: Info: operator &operators.Maxpool{name:"Maxpool", Pads:[]int{4, 4}, AutoPad:"", StorageOrder:0, KernelShape:(3, 3), Strides:[]int{1, 1}}
    maxpool_autogenerated_test.go:269:
                Error Trace:    maxpool_autogenerated_test.go:269
                Error:          Not equal:
                                expected: (1, 3, 30, 30)
                                actual  : (1, 3, 22, 22)

                                Diff:
                                --- Expected
                                +++ Actual
                                @@ -3,4 +3,4 @@
                                  (int) 3,
                                - (int) 30,
                                - (int) 30
                                + (int) 22,
                                + (int) 22
                                 }
                Test:           TestMaxpool_2d_pads
                Messages:       Tensors should be the same
    maxpool_autogenerated_test.go:270:
                Error Trace:    maxpool_autogenerated_test.go:270
                Error:          Max difference between -3.4028235e+38 and 1.7640524 allowed is 1e-05, but difference was -3.4028234663852886e+38
                Test:           TestMaxpool_2d_pads
                Messages:       Tensors should be the same
FAIL
exit status 1
FAIL    github.com/owulveryck/gorgonnx/operators        0.017s