https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103387
--- Comment #14 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-12 branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:8caf5805ad76125b84430b8653003f4776489d46 commit r12-9462-g8caf5805ad76125b84430b8653003f4776489d46 Author: Jonathan Wakely <jwak...@redhat.com> Date: Thu Apr 20 21:02:22 2023 +0100 libstdc++: Optimize std::try_facet and std::use_facet [PR103755] The std::try_facet and std::use_facet functions were optimized in r13-3888-gb3ac43a3c05744 to avoid redundant checking for all facets that are required to always be present in every locale. This performs a simpler version of the optimization that only applies to std::ctype<char>, std::num_get<char>, std::num_put<char>, and the wchar_t specializations of those facets. Those are the facets that are cached by std::basic_ios, which means they're used on construction for every iostream object. This smaller change is suitable for the gcc-12 branch, and mitigates the performance loss for powerpc64le-linux on the gcc-12 branch caused by r12-9454-g24cf9f4c6f45f7 for PR 103387. It also greatly improves the performance of constructing iostreams objects, for all targets. libstdc++-v3/ChangeLog: PR libstdc++/103755 * include/bits/locale_classes.tcc (try_facet, use_facet): Do not check array index or dynamic type when accessing required specializations of std::ctype, std::num_get, or std::num_put. * testsuite/22_locale/ctype/is/string/89728_neg.cc: Adjust expected errors.
