[Bug libstdc++/80826] Compilation Time for many of std::map insertions

["rguenth at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80826

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hubicka at gcc dot gnu.org

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
Looking at callgrind profile shows that early inlining is the TV_INTEGRATION
culprit with expand_call_inline -> cgraph_node::remove -> .. ->
cgraph_node::find_replacement () being the culript showing

      /* Update clone_of pointers.  */
      n = new_clones;
      while (n)
        {
          n->clone_of = next_inline_clone;
          n = n->next_sibling_clone;
        }

as hottest.  The whole function looks like having bad complexity if there are a
lot of inline clones (we call the same function very many times and likely
inline all of them).  I suspect handling this higher up in the chain would be
more
efficient than doing this in expand_call_inline ...