https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66963
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Andrew Pinski from comment #1) > I thought this is documented somewhere but __builtin_choose_expr only really > accept constant literals and not constexprs. And the main reason is the __builtin_choose_expr chooses the expression before semantics analysis happens so the first argument needs to be a constant literal.
