https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116035
--- Comment #4 from Christoph Müllner <cmuellner at gcc dot gnu.org> --- I understood this as GCC 14 and 15 (i.e., master) show this issue. Testing with GCC 13 shows: error: '-march=rv64g_xtheadmemidx_zba': unexpected ISA string at end: 'zba' The issue does not apply to GCC 13 or older because the affected extensions were not supported back then. By the way thanks for reminding me of the GCC 14 backport.