https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69504
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
I think at some point the FEs created array-refs here. I think I suggested
that elsewhere during last stage1 but nobody implemented that ... (now it's
already again quite late).
Thus for vector[i] create
ARRAY_REF<VIEW_CONVERT <array-type-for-vector-type> (vector), i>
avoiding the need to take the address of vector.
Thus instead of
bool non_lvalue
= convert_vector_to_pointer_for_subscript (loc, &array, index);
convert the vector to an array type via a VIEW_CONVERT. That should work
for both r and lvalues. Of course it may trigger interesting new paths
should this survive until RTL expansion ;)
The other option is in convert_vector_to_pointer_for_subscript, force
the !lvalue_p path for DECL_HARD_REGISTER *vecp.
