[Bug libstdc++/54075] [4.7.1] unordered_map 3x slower than 4.6.2

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54075

--- Comment #17 from Paolo Carlini <paolo.carlini at oracle dot com> 2012-07-26 
22:55:15 UTC ---
Because of more rehashing, unrelated to reserve, I suppose?