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

[chip at pobox dot com]

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

--- Comment #16 from Chip Salzenberg <chip at pobox dot com> 2012-07-26 22:50:17 UTC ---
In my tests, with this patch, 4.7.1 is about 10% slower than 4.6 ... a vast
improvement but certainly not parity.

./bench46  1.75s user 0.82s system 99% cpu 2.577 total
./bench47  8.01s user 2.78s system 99% cpu 10.800 total
./bench47+patch  1.95s user 0.80s system 99% cpu 2.764 total