[Bug target/86735] [8/9 Regression] Bad wrong-code bug with "-march=skylake-avx512 -Ofast"

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86735

--- Comment #8 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
On x86_64-apple-darwin17 without access to avx512, I see

% gfcp pr86735.f90 -Ofast -march=skylake
% ./a.out
           1           2           3           4           5           6       
   7           8           9          10          11          12          13   
      14          15          16

Program received signal SIGILL: Illegal instruction.

and

% gfcp pr86735.f90 -Ofast -march=haswell
% ./a.out
           1           2           3           4           5           6       
   7           8           9          10          11          12          13   
      14          15          16

Program received signal SIGILL: Illegal instruction.

but

% gfcp pr86735.f90 -Ofast -march=ivybridge
% ./a.out
           1           2           3           4           5           6       
   7           8           9          10          11          12          13   
      14          15          16
           1           2           3           4           5           6       
   7           8           9          10          11          12          13   
      14          15          16

Is this the same bug or should I file a new one?