http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51119
Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |Joost.VandeVondele at mat | |dot ethz.ch --- Comment #8 from Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> 2012-06-29 07:19:03 UTC --- (In reply to comment #7) > (In reply to comment #6) > > Janne, have you had a chance to look at this ? For larger matrices MATMMUL > > is > > really slow. Anything that includes even the most basic blocking scheme > > should > > be faster. I think this would be a valuable improvement. > > I implemented a block-panel multiplication algorithm similar to GOTO BLAS and > Eigen, but I got side-tracked by other things and never found the time to fix > the corner-case bugs and tune performance. IIRC I reached about 30-40 % of > peak > flops which was a bit disappointing. I think 30% of peak is a good improvement over the current version (which reaches 7% of peak (92% for MKL) for a double precision 8000x8000 matrix multiplication) on a sandy bridge. In addition to blocking, is the Fortran runtime being compiled with a set of compile options that enables vectorization ? In the ideal world, gcc would recognize the loop pattern in the runtime library code, and do blocking, vectorization etc. automagically.