https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109493
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- belt_mac_st* st = &state; belt_mac_st* st2 = &state2; ((word*)(st->s))[0] = 0, ((word*)(st->s))[1] = 0; ((word*)(st->r))[0] = 0, ((word*)(st->r))[1] = 0; st->filled = 0; I am 99% sure those are aliasing rule violations. Does -fno-strict-aliasing help?
