Re: Follow-on from does Lua need a JIT - making Lua's interpreter faster

[Sergey Rozhenko <sergroj@...>]

On Ср 22.02.17 22:13, Dibyendu Majumdar wrote:
> It seems from the majority of responses so far that JIT is not
> essential for Lua, or putting it another way, a majority of use cases
> can be satisfied without a JIT.
>
> A natural follow on question is can the interpreter be made faster
> without resorting to hand-written assembly code or other esoteric
> optimisations?
Big Yes. When I switched from plain Lua to LuaJIT I was very happy with 
the speedup. I didn't run the numbers, but it felt like 10x increase in 
speed. Then I found out that mobdebug.lua was disabling JIT, so all this 
speedup was from faster interpreter. Speedup from enabling JIT wasn't 
nearly as big.
This speedup probably comes from faster table access, but I don't know 
how LuaJIT achieves it.
What I also love about LuaJIT is that it's the golden standard of Lua in 
terms of language design. Lua 5.3 has suffered a huge degradation in 
that area due to its combined int64/double type.

Best regards,
Sergey "GrayFace" Rozhenko,                 mailto:sergroj@mail.ru