Résumé
International Symposium on Parallel Symbolic Computation, Grenoble : France (2010) We propose different implementations of the sparse matrix--dense vector multiplication () for finite fields and rings$\Zb/m\Zb$ . We take advantage of graphic card processors (GPU) and multi-core architectures. Our aim is to improve the speed of in the library, and henceforth the speed of its black box algorithms. Besides, we use this and a new parallelization of the sigma-basis algorithm in a parallel block Wiedemann rank implementation over finite fields.