Re: [Libjit] libjit about 1000 times slower than native functions

[Omkar Wagh]

Hi
On 09/17/2013 01:06 PM, Aleksey Demakov wrote:
> Yes, jit_apply mechanism is slow. When calling small JIT-ted functions 
> from C almost all time is going to be spent switching from C to JIT 
> runtime rather then executing the function itself. So it's going to 
> perform poorly. For a more accurate idea how fast would be JITed code 
> it is better to benchmark a function that performs some computation 
> many times in a loop or recursively. 
So our use case is actually a few small expressions (dynamically given) 
that we'd like to compile to native code. Response time is very critical 
but start-up time (one time compilation) not so much...

I can see from your answer that libjit probably won't be useful for us. 
Can you recommend something that might help us (better than building an 
expression tree evaluator which we already have)? I was thinking of 
compiling it into a shared library (.so) and loading it immediately but 
are there some standard tools to do that?

Regards,
Omkar