well in many programs. • In some recursive functions, tracing JIT performs worse. 2019/4/2 <Programming> 2019 2 What is the problem? 0 0.2 0.4 0.6 0.8 tak fib geo_mean Pyrlang HiPE 0 0.2 0.4 0.6 0.8 1 tak fib geo_mean Pycket Larceny Pyrlang[R. Huang, el. al., ‘16] vs. HiPE Pycket[S. Bauman, el. al. ,‘15] vs. Larceny Tracing JIT (RPython) vs. AOT compiler better better