https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81821
Oleg Endo <olegendo at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Summary|[RX] __atomic_test_and_set |[RX] xchg_mem<mode> uses |overwrites adjacent memory |wrong memory operand size --- Comment #1 from Oleg Endo <olegendo at gcc dot gnu.org> --- As it turns out, the xchg_mem<mode> pattern does not output a specifier. So this problem is not only restricted to __atomic_test_and_set, but also to 8 bit and 16 bit atomic exchange builtins.