[Bug driver/79569] Unrecognized command line option ‘-m3dnowa’

["ubizjak at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79569

--- Comment #3 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to Jakub Jelinek from comment #1)
> I bet this goes all the way down to r125180 or so, ix86_handle_option
> returns false for OPT_3dnowa.  So, either the option should not be
> recognized, then we should add Ignore to it etc., or we should make it work
> (again?).  Right now it seems the effect of -m3dnowa happens only if -march=
> for a CPU that includes 3dnowa is included.

This option is marked as Undocumented in i386.opt.

Ages ago, it made sense to switch it only with -march= option. Nowadays we
should handle it as we handle other options. So, your patch is OK in this
regard, but please remove Undocumented from i386.opt and add this option to
doc/invoke.texi.