[mraleph]

When you say "JIT compilers are notoriously tricky to implement" what, I think, you actually mean is "optimizations for dynamically typed languages are notoriously tricky to implement".

If the language you need to compile is Lua - then it does matter whether you are trying to compile it just-in-time or ahead-of-time. Both would be hard to implement if you care about performance (and implementing an AOT compiler that produces fast code would probably be even harder than JIT).

Similarly if your language is like Pallene - which reminds me of Oberon-2 of all things, then you can implement both AOT and JIT with much less effort.

That does not however mean that AOT is trivial to write - as you increase the expressivity of the language and add more ways to write abstract code so does the complexity of optimizing away the cost of those abstractions (eliminating indirections and allocations, resolving polymorphic calls statically, etc)

Finally at some point, even a language like Pallene might benefit from a JIT - because of JITs' ability to see the execution and focus on actually taken execution paths, rather then looking at the program as whole and not knowing which paths would actually be taken.

[hugomg]

You hit the nail on the head. With a more "Oberon-like" language we can use textbook optimization algorithms and take advantage of existing compiler backends, like GCC and LLVM. For dynamic languages these techniques aren't enough so more sophisticated JIT compilation seems to be the only option.