[Bug libfortran/51119] New: MATMUL slow for large matrices

[jb at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51119

             Bug #: 51119
           Summary: MATMUL slow for large matrices
    Classification: Unclassified
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: libfortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: jb@gcc.gnu.org


Compared to ATLAS BLAS on an AMD 10h processor, MATMUL on square matrices with
n > 256 is around a factor of 8 slower. 

While I don't think it's worth spending the time on target-specific parameters
and/or asm-coded inner kernel as high-performance BLAS implementations do, I
suspect that a little effort towards cache blocking could improve things.