Tail-Recursive & Body-Recursive Function Performance Across Elixir & BEAM versions – what’s the impact of the JIT?

Finally having finished my own little yak-shave of figuring out a performance problem and releasing benchee 1.3.0 to fix it here is what I was up to: Taking my old blog post about body-recursive vs. tail-recursive functions and benchmarking it across Elixir & Erlang versions from 1.6 @ OTP 21 up to 1.16 @ OTP 26 and see:

  • How much faster have we gotten? What was the impact of the JIT?
  • Did the performance characteristics change? (aka what’s the fastest for which input)

And spoiler alert, we got quite a bit faster and performance charteristics changed - read on to learn more!