[mlochbaum]

Bidirectional isn't benchmarked here, and only mentioned once offhand:

> For example, we could already start searching for elements at the slot with expected (average) displacement from their perfect slot and probe bidirectional from there. In practice, this is not very efficient due to high branch misprediction rates and/or unfriendly access pattern.

I think this indicates a regular Robin Hood insertion and modified search, which doesn't sound that similar to Amble and Knuth's method. And anyway the relative costs of mispredictions and cache misses vary wildly based on workflow (paper studies 8-byte keys only). The paper also doesn't present Robin Hood as a clear winner, which is how I interpreted your comment. It's shown as one of five suggestions in the decision graph at the end, and only recommended for load factors between 50% and 80% among other conditions.

Edit: And the paper is from 2015, not the last five years. Is this the right link?