This paper presents a complete end-to-end framework to generate automatic message-passing code for tiled iteration spaces. It considers general parallelepiped tiling transformations and general convex iteration spaces. We aim to address all problems concerning data parallel code generation efficiently by transforming the initial non-rectangular tile to a rectangular one. In this way, data distribution and communication become simple and straightforward. We have implemented our parallelizing techniques in a tool which automatically generates MPI code and run several experiments on a cluster of PCs. Our experimental results show the merit of general parallelepiped tiling transformations, and confirm previous theoretical work on scheduling-optimal tile shapes.