https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105049
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
We have
return VIEW_CONVERT_EXPR<U>( VEC_PERM_EXPR < {<<< Unknown tree:
compound_literal_expr
V D.1984 = { 0 }; >>>, { 0 }} , {<<< Unknown tree:
compound_literal_expr
V D.1985 = { 0 }; >>>, { 0 }} , { 0, 0 } > & {(short int) SAVE_EXPR
<c>, (short int) SAVE_EXPR <c>});
where we gimplify the init CTORs to
_1 = {{ 0 }, { 0 }};
_2 = {{ 0 }, { 0 }};
instead of to vector constants. That later runs into a bug in uniform_vector_p
which doesn't handle CTORs of vector elements correctly. Only forwprop
eventually folds those.
I have a patch to fix both issues.
