DBG((dbg, LEVEL_4, "\tusedef chain for block\n"));
list_for_each_entry(border_t, b, head, list) {
DBG((dbg, LEVEL_4, "\t%s %+F/%d\n", b->is_def ? "def" : "use",
DBG((dbg, LEVEL_4, "\tusedef chain for block\n"));
list_for_each_entry(border_t, b, head, list) {
DBG((dbg, LEVEL_4, "\t%s %+F/%d\n", b->is_def ? "def" : "use",