Various approach on core VM implementation with speed test on Fibonacci function.
I compare lua, luaJIT, luavm with my core evaluation of rust_stack, rust_tree, 1byte_format and the native rust_native. Then, the same thing, with a tail call optimization version for all of them (six in total).
As lua, luaJIT, luavm share the same fib.lua, while my impls will have their custom rival with _tail postfix.
-
With recursion call => fib(30):
luajit 0.011 rust_native 0.012 lua 0.078 luavm 1.925 rust_stack 7.232 1byte_format 9.826 rust_tree 35.151 -
With
tail call optimization=> fib(30, 0, 1):luajit 0.003 rust_stack_tail 0.003 rust_native_tail 0.003 lua 0.004 rust_tree_tail 0.004 1byte_format 0.004 luavm 0.006 -
With
i128+ TCO => fib(100, 0, 1) with 10 runs :rust_native_tail 0.003 luajit 0.004 lua 0.004 1byte_format 0.004 rust_stack_tail 0.004 luavm 0.007 rust_tree_tail 0.008
I think this is where compilers did some tricky optimization to turn recursive call version into tail call optimization version. Which is why their non-TCO and TCO version have close results while I have to optimize the common version to speed up.
1byte_format && rust_stack_tail are the same 100 loops like every others but 1byte_format have 400 more instructions to execute than rust_stack_tail.
When there's no (or less) difference in algorithm/compiler optimization, the direct call from a series of instructions could be just as fast as native code or JITed, bytecode execution.