Hi Toon, On 12/15/18 16:49, Toon Moene wrote: > It is probably helpful to ask this question on the GNU Fortran mailing > list (copied here), as more Fortran developers are listening there ... > > Two questions off-hand: > > 1. Do you have a small test case that shows the problem ? not yet. I'd need to sample from the data (matrices) used, in case it turns out due to different tuning in gcc-9. I was hoping that one of the codes on https://www.gnu.org/software/gcc/benchmarks/ already covers this kind of pattern. > 2. Is this single- or multi-threaded code ? The CSC times vector code is just the vanilla Fortran version, and the CSR times vector uses simple OpenMP, so this is nothing fancy. Thanks, Harald > On 12/13/18 10:31 PM, Harald Anlauf wrote: >> Hello, >> >> is there a public gcc benchmark that checks for performance >> regressions in particular for sparse-matrix vector multiplication? >> >> I've noticed (and confirmed by perf measurements) a significant >> performance drop on x86_64/Skylake from gfortran-8 to gfortran-9 >> (current trunk version) for a code that uses both CSC and CSR >> storage. gfortran-8 performance is the same as gfortran-7. >> >> Thanks, >> Harald >> > > Kind regards, >
