[Bug middle-end/96750] 10-12% performance decrease in benchmark going from GCC8 to GCC9/GCC10

[mattreecebentley at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96750

--- Comment #6 from Matt Bentley <mattreecebentley at gmail dot com> ---
Created attachment 49278
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=49278&action=edit
Demonstration of code which doesn't trigger the performance anomaly.

plf_colony_fast.h does not trigger the problem, has one branch eliminated in
each insert/emplace function.