--- Comment #8 from Alexander Monakov <amonakov at gcc dot gnu.org> ---
Honza: ping :). ipa-pure-const might be a better place to mark functions with
compiler memory barriers, as it already computes and propagates "nonfreeing"
property (thus computing "nonbarrier" in ipa-pure-const would allow to use it
in implementation of nonbarrier_call_p).
OTOH ipa-pure-const is optional, so with -fno-ipa-pure-const, ipa-reference
would see most functions as compiler memory barriers. Although it's possible
to rescan bodies of those functions that ipa-pure-const did not scan, that