support ceil mode by padding changes (#21310)
Summary:
Modify MKLDNN pooling operation to support ceil mode by adjusting the right/bottom padding accordingly. This is done similarly as in Caffe (see discussion https://github.com/pytorch/pytorch/pull/19205#discussion_r276903751).
To make this possible, I split the padding to left and right (top / bottom). This naming is confusing but actually follows mkldnn's own naming for pooling::compute(). We increase the r paddings so that it matches the ceiling mode expected output size.
Strengthened the test case.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21310
Reviewed By: bddppq
Differential Revision: D15611664
Pulled By: akyrola
fbshipit-source-id: 46b40015dafef69a8fd5e7b2c261d8dbf448cd20
