[Bug target/114232] [14 regression] ICE when building rr-5.7.0 with LTO on x86

[rguenther at suse dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114232

--- Comment #14 from rguenther at suse dot de <rguenther at suse dot de> ---
On Tue, 5 Mar 2024, jakub at gcc dot gnu.org wrote:

> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114232
> 
> Jakub Jelinek <jakub at gcc dot gnu.org> changed:
> 
>            What    |Removed                     |Added
> ----------------------------------------------------------------------------
>                  CC|                            |jakub at gcc dot gnu.org
> 
> --- Comment #12 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
> Still, it would be nice to understand what changed optimize_function_for_size_p
> (cfun)
> after IPA.  Is something adjusting node->count or node->frequency?
> Otherwise it should just depend on the optimize_size flag which should not
> change...

Maybe we share the TREE optimization node (it gets re-materialized
during LTO streaming) between hot and cold functions and the "first"
one getting in set_cfun will overwrite TREE_OPTIMIZATION_OPTABS in
init_tree_optimization_optabs (though it seems to overwrite things).

In any case I think the tree node sharing only looks at options, not
at function frequency so having TREE_OPTIMIZATION_OPTABS part of
the optimization node looks a bit fragile in the light of sharing.