https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107304
--- Comment #8 from Hongtao.liu <crazylht at gmail dot com> ---
(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.
