http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52080
--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-02-01 10:25:21 UTC --- SPARC64 also can do 32bit loads/stores as the following testcase shows: struct x { long a; unsigned int lock; unsigned int full; }; void wrong(struct x *ptr) { ptr->full = 1; } here we simply use a 32bit store.