On Fri, 26 May 2023 at 10:31, Hagen Paul Pfeifer wrote: > > * Jonathan Wakely via Gcc | 2023-05-26 08:30:06 [+0100]: > > >On Fri, 26 May 2023, 08:01 Andrew Pinski via Gcc, <gcc@gcc.gnu.org> wrote: > > > >> > GCC 13.3: gcc -m32 -O3 demo.c > >> > > >> > NOTE: -mtune=native is the default! > >> > >> You need to use -march=native and not -mtune=native .... to turn on > >> the architecture features. > > > >Yes this is just user error. You didn't use the right options to say you > >want SSE2. GCC supports it fine already. > > > >This is also the wrong mailing list for this kind of question, please use > >gcc-h...@gcc.gnu.org for this kind of thing, thanks. > > Correct, that was also my first thought - but: this mistake has been repeated > again and again for decades. Here specifically Stefan Kanthak realized that > something is wrong - in many cases simply mtune=native is used and the error > is not realized.
I suppose we could give a warning if -mtune is used without an explicit -march but it would probably annoy a lot of people. It's not *always* wrong to use -mtune without -march. It's fine if you know what the compiler's default -march is and you're happy with that default. > Maybe we should think about how you can support the users better? Maybe by an > explicit hint in the documentation or by a info message at execution time. And > for such discussions this is the right mailing list! ;-) Yes :-)
