[Bug fortran/68600] Inlined MATMUL is too slow.

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68600

--- Comment #1 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
Created attachment 36864
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36864&action=edit
Code used for the timings