http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58950
--- Comment #4 from Marc Glisse <glisse at gcc dot gnu.org> --- (In reply to Manuel López-Ibáñez from comment #3) > You could decorate __builtin_shuffle with attribute "warn_unused_result". It > is not the same, but it probably more precise. It would also warn for: > __builtin_shuffle(x,++m), while -Wunused-value would not. Would it? The front-ends replace __builtin_shuffle with VEC_PERM_EXPR quite early. I am not even sure we have a function type to which we could attach the attribute.
