https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64722
--- Comment #2 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
Indeed, adding this to toplev.c fixes the issue:
@@ -2166,7 +2169,8 @@ toplev::finalize (void)
{
rtl_initialized = false;
this_target_rtl->target_specific_initialized = false;
+ this_target_rtl->x_pic_offset_table_rtx = NULL;
/* Needs to be called before cgraph_c_finalize since it uses symtab. */
ipa_reference_c_finalize ();
fixes the issue; 5 iterations of test-hello-world.c run to completion.
