perf regression in vbench stat_ops_* in 0.11.0.rc1
![stat_ops](https://f.cloud.github.com/assets/1820866/377772/3a751b52-a4eb-11e2-933d-954a9b87206c.png)

f84c9c6    5.308533
5d8eb29    4.900217
6dec888    5.946970
d88d76e    5.022049
