What it comes down to is that predictable indirect branches are well-predicted. It does not require any insider information to verify this about Intel architect

What it comes down to is that predictable indirect branches are well-predicted. It does not require any insider information to verify this about Intel architecture processors. I built a "fake interpreter" a while back and found that branch misses in predictable sequences of interpreter code are very unlikely unless there is a longish common prefix of interpreter indirect branches in two interpreter sequences (i.e. one sequence goes ABCDEFGH and the other goes ABCDEFGZ). This led us down a path of also using an interpreter within our own regex engine (Hyperscan) - not for individual engines like NFA/DFA/literal match but for the overall orchestration layer. It's been quite an improvement of code cleanliness and generally has been either performance-neutral or even good. When you replace a great big ugly clagged "if this rare thing happens, go do this code, or else if this happens, go do this other things, then ..." with an interpreter you can get nice performance benefits in the common case - even though there are not branch misses in the "giant clagged pile of code" anti-pattern.