On Sat, Aug 12, 2023 at 10:41:10AM -0300, Jorge D'Elia via Fortran wrote:
>
> $ test-march.exe
>
> Program received signal SIGILL: Illegal instruction.
>
This, to me, suggests that the backend is emitting a wrong
assembly language code. I suspect that you'll need to
compare the generated assembly code between a working
gfortran and the bad gfortran. It is also possible to get
a listing of the actually options that -march=native activates.
For example,
% gfcx -o z -O -march=native --verbose a.f90
It is the options that begin with -m that matter. For my hardware
I see 108 such options. With patients you can determine if one
of these triggers the issues.
One can also scan gcc/gcc/ChangeLog for changes to config/i386/i386.md.
For example
2023-08-07 Jan Beulich <jbeul...@suse.com>
* config/i386/i386.md (sse4_1_round<mode>2): Make
"length_immediate" uniformly 1.
* config/i386/mmx.md (mmx_pblendvb_v8qi): Likewise.
(mmx_pblendvb_<mode>): Likewise.
There are at least 10 commits on 2023-08-07 to this file.
Finally, as a non-git user, you can always try git's bisection
feature to identify where things go left.
--
Steve
