https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109661
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> --- When it is changed to typedef unsigned long U __attribute__ ((aligned (256))); typedef enum : U { V = 0 } W; U foo (U a, W b) { return a + U (b); } the ICE started earlier, maybe r13-5123-g3df1a115be22caeab3 ?