I haven't tested this either, but why would the branch be "largely unpredictable"? It's always going to evaluate to false except once, and the one time it evaluates to true the rest of the search will be finished within the branch.
I’m referring to exactly that misprediction when the branch triggers. It’s only predictable if the input arrays always has the same length log2, and it’s called in a loop so the history is there.
