Hi! ia64 seems to be affected too, but the backend doesn't have any -Wpsabi warnings and I'm not sure if we really need them for an (almost?) dead target.
Untested by me, but Andreas confirmed it fixed all struct-layout-1.exp regressions. Ok for trunk? 2020-04-22 Jakub Jelinek <ja...@redhat.com> PR target/94706 * config/ia64/ia64.c (hfa_element_mode): Ignore cxx17_empty_base_field_p fields. --- gcc/config/ia64/ia64.c.jj 2020-01-12 11:54:36.338414540 +0100 +++ gcc/config/ia64/ia64.c 2020-04-22 12:49:59.627563114 +0200 @@ -4665,7 +4665,7 @@ hfa_element_mode (const_tree type, bool case QUAL_UNION_TYPE: for (t = TYPE_FIELDS (type); t; t = DECL_CHAIN (t)) { - if (TREE_CODE (t) != FIELD_DECL) + if (TREE_CODE (t) != FIELD_DECL || cxx17_empty_base_field_p (t)) continue; mode = hfa_element_mode (TREE_TYPE (t), 1); Jakub