AMG based on compatible weighted matching for GPUs

We describe main issues and design principles of an efficient implementation, tailored to recent generations of Nvidia Graphics Processing Units (GPUs), of an Algebraic Multigrid (AMG) preconditioner previously proposed by one of the authors and already available in the open-source package BootCMatch: Bootstrap algebraic multigrid based on Compatible weighted Matching for standard CPUs.This work has been partially supported by the EC under the Horizon 2020 Project Energy Oriented Center of Excellence (EoCoE II): Toward Exascale for Energy, Project ID: 82415