https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107304
--- Comment #10 from Hongyu Wang <wwwhhhyyy333 at gmail dot com> ---
(In reply to H.J. Lu from comment #9)
> (In reply to Hongtao.liu from comment #8)
> > (In reply to H.J. Lu from comment #7)
> > > (In reply to Hongtao.liu from comment #6)
> > > > (In reply to Hongtao.liu from comment #5)
> > > > > (In reply to H.J. Lu from comment #4)
> > > > > > Since the default is -march=tigerlake, it enables AVX512 in the
> > > > > > middle end.
> > > > > > When "arch=alderlake" disables AVX512, we fails to expand AVX512 to
> > > > > > non-AVX512
> > > > > > ISAs. It means that target_clones can't be more restrictive than the
> > > > > > default. We
> > > > > > should provide better diagnostics.
> > > > >
> > > > > Is there any place checking ISA difference for target_clones?
> > > >
> > > > ix86_valid_target_attribute_inner_p?
> > >
> > > It may not have all ISA infos. Will this
> > >
> > > diff --git a/gcc/config/i386/i386-options.cc
> > > b/gcc/config/i386/i386-options.cc
> > > index acb2291e70f..1efaae132e9 100644
> > > --- a/gcc/config/i386/i386-options.cc
> > > +++ b/gcc/config/i386/i386-options.cc
> > > @@ -2953,6 +2953,14 @@ ix86_option_override_internal (bool main_args_p,
> > > fine grained control & costing. */
> > > SET_OPTION_IF_UNSET (opts, opts_set, param_vect_partial_vector_usage,
> > > 0);
> > >
> > > + if (!main_args_p
> > > + && &global_options != opts
> > > + && (((opts->x_ix86_isa_flags & global_options.x_ix86_isa_flags)
> > > + != global_options.x_ix86_isa_flags)
> > > + || ((opts->x_ix86_isa_flags2 & global_options.x_ix86_isa_flags2)
> > > + != global_options.x_ix86_isa_flags2)))
> > > + error ("Target ISAs are more restrictive than the default");
> > > +
> > > return true;
> > > }
> > >
> > > work?
> >
> > Looks reasonable to me.
>
> It doesn't work since we may use target attribute to disable MMX/SSE/SSE2.
> This problem seems to be __builtin_shuffle related.
Clang works properly as it overrides -march= to any target clones. I suppose we
can do similar things in ix86_valid_target_attribute_p
https://godbolt.org/z/v7xT1zahd
