As you stated, targeting numerical code (array access and primitive operations) versus general code (with modern features such as virtual dispatch, varargs, gen

As you stated, targeting numerical code (array access and primitive operations) versus general code (with modern features such as virtual dispatch, varargs, generics or even metaprog) is completely different in terms of difficulty and solutions. It is indeed fairly easy to create a highly performant JIT for numerical operations on N-dimensional arrays (vector,matrix..etc..); and depending on your field, it might represent 99% of the execution time. For example, I wrote a really simple JIT compiler for Matlab which performs sometimes better than raw C (and it's backed by LLVM vectorizer to generate the correct SIMD assembly). Link to the Master thesis if you are interested: https://www.dropbox.com/s/caz7d4d08xhbwcu/thesis.pdf?dl=0 https://www.dropbox.com/s/caz7d4d08xhbwcu/thesis.pdf?dl=0