https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82897
--- Comment #7 from Uroš Bizjak <ubizjak at gmail dot com> --- Another idea is to add an "nopromote" attribute to builtin decl (in ix86_Add_new_buitins), detect this attribute in TARGET_PROMOTE_PROTOTYPES and disable promotion in this case. If this approach works, we can perhaps selectively add "nopromote" attribute to masked builtins.