On Wed, Feb 14, 2018 at 6:15 PM, Jed Brown <j...@jedbrown.org> wrote:
> Richard Tran Mills <rtmi...@anl.gov> writes: > > > On Tue, Feb 13, 2018 at 8:48 PM, Jed Brown <j...@jedbrown.org> wrote: > > > >> Richard Tran Mills <rtmi...@anl.gov> writes: > >> > >> > I haven't experimented very thoroughly with it (hmm... should > probably do > >> > such experiments), but I believe that, once matrix rows become > >> sufficiently > >> > long, then SELL doesn't provide an advantage over AIJ. > >> > >> What is the performance model that explains why SELL doesn't benefit > >> from long rows? It's clear for large blocks where BAIJ can be compiled > >> to vectorized loads and stores, but much less clear when AIJ is > >> producing basically scalar code. > >> > > > > Hmm. I may be mistaken in my statements about long rows and AIJ -- I > think > > it might be the case that every matrix with long rows for which I've seen > > the decent performance with AIJ was something that uses and benefits from > > the Inode versions of the routines. > > Have you tested that Inodes are an improvement? I've seen the opposite > (by about 5%) on some recent Intel. > I have not tested this. I should give this a try and look into what is going on, either way. --Richard [...]