[MLIR] Representing right-padded MemRefs using semi-affine maps

Hi all,

I was hoping to get some clarification on how semi-affine mappings work in padding representation.
My understanding is that the example below represents a MemRef with padding at the front of the slowest dimension:

 memref<784x512xf32, affine_map<(d0, d1) -> (d0 + 48, d1)>>

If I normalise this MemRef I get the following output (as expected):

memref<832x512xf32>

My questions is, if I wanted to represent padding at the end of slowest dimension, how do I do that using an affine map?
Thanks