https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81519
--- Comment #9 from Eric Gallager <egallager at gcc dot gnu.org> --- (In reply to Daniel Santos from comment #7) > (In reply to Martin Liška from comment #4) > > Ok, so I've briefly investigated source code and providing such information > > is definitely not a simple task :/ > > > > I would recommend to fix PR39851 and then one will just compare output of > > following 2 invocations: > > > > gcc --help=target -Q > > gcc --help=target -march=native -Q > > > > Will it work for you? > > > > Note that fully understand which ISA extensions are enable when is also > > quite complex. > > I've thought about this some more and I'm starting to think that all of this > can be determined with a script that iteratively calls gcc --help=target -Q > with various machine flags to determine which -mno-* flags are really needed > and which -m<isa> flags include others. So in effect, I'm thinking that we > can produce optimal C(XX)FLAGS with a script and your PR39851 fix. I'll > have to test this out. > > Thanks If you come up with a script, do you want to put it in contrib?
