https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64314 --- Comment #2 from Lars Gullik Bjønnes <larsbj at gullik dot net> --- I still see this, but with current gcc5 the call stack has become a bit deeper, instead of 5 calls to walk_tree_1 I now see 9 calls. (with -std=gnu++14 in this case.)