i am not sure if this really is jit compiling? c-script compiles ahead of time. it just does it every run.

i think with most jit compilers the code first gets run by the interpreter and then a code analysis happens which tries to find the hotspots that make most sense to be compiled. the machine code results also often get cached for further runs.

theoretically this should be an advantage because the jit compiler has more information about the code and its runtime behavior than a normal compiler. better optimization should be possible because of that. it's just that normal compilers are around much longer and still have many more years of research invested into them but eventually jit compilers will catch up.