Draft: Enable non uniform tile sizes

The goal of this MR is to enable non uniform tile sizes. This is a first step where all computations of dimensions which are the usual formula:

tempXY = X == desc->Yt - 1 ? desc->Y - X * desc->Yb : desc->Yb;

need to be replaced by a function that takes into account at least desc, X and Y, but that may not work in all cases, so this is an ongoing work.