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.
