One of the main BLAS implementations (where lots of numerical computation spends 99% of its time) is OpenBLAs, hand-crafted assembly per CPU. Main competitor is Intel MKL, closed source.
Even if you could interpret that code, your JIT-ing is not going to create exactly the same assembly and will thus perform worse. You can very easily get a C implementation that you can interpret easily but at least as output by a C compiler, that performance is nowhere near where you want to be.
(I realize this is not a problem though, just have the JIT call the libraries, as long as the wrapper can be interpreted you are good.)
Even if you could interpret that code, your JIT-ing is not going to create exactly the same assembly and will thus perform worse. You can very easily get a C implementation that you can interpret easily but at least as output by a C compiler, that performance is nowhere near where you want to be.
(I realize this is not a problem though, just have the JIT call the libraries, as long as the wrapper can be interpreted you are good.)