JIT compilation speed

[Dibyendu Majumdar]

On 27 July 2015 at 23:20, Basile Starynkevitch <basile@starynkevitch.net> wrote:
>>> Is there a timeframe for the performance improvements to the JIT
>>> compilation speed?
>>
>> The patch kit I posted here:
>>    https://gcc.gnu.org/ml/gcc-patches/2015-06/msg00116.html
>> gives about a 5x speedup (from about 50ms down to about 10ms on my box),
>

Ok, that seems good improvement. I don't have a specific benchmark but
I have noticed that when I enable full compilation the Lua test suite
takes 4-5 times longer to run compared to LLVM - in both cases the JIT
compilation time dominates - so improvement of 5x may put libgccjit in
the same ballpark as LLVM. That would be good enough to start with.

>
> So, for Dibyendu Majumdar: if the GCCJIT compilation time matters a lot to
> you in RAVI and the performance of the emitted machine code matters much
> less to you, I am afraid that GCCJIT is not the optimal library for your
> needs in RAVI (using GNU lightning or asmjit would make JIT-ing time much
> faster, at the expense of a produced machine code which runs 2 to 5 times
> slower than what GCCJIT can achieve with -O1).
>

Yes understand that - I think that libgccjit needs to be at least as
efficient as LLVM - that should be good enough.

Regards
Dibyendu