https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106565
kargl at gcc dot gnu.org changed:
What |Removed |Added
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CC| |kargl at gcc dot gnu.org
--- Comment #3 from kargl at gcc dot gnu.org ---
> INTEGER, PARAMETER :: m = 200, n = 300, nn = 150
> REAL :: A(m,n), B(nn,n), C(m,nn), BB(n,nn)
> INTEGER :: i, j, k, L
If you are doing a problem of this size or larger, you want to use the
-fexternal-blas option and link in OpenBLAS.
I added timing code and replicated the loop to both in one go.
% gfcx -o z -O3 -march=native a.f90 && ./z
1.16500998 1615.08594
5.32258606 1615.08020
% gfcx -o z -O3 -march=native a.f90 -fexternal-blas -lopenblas && ./z
2.44668889 1615.08301
1.99379802 1615.08301
