Re: [PATCH] Re: Bignum performance

[Emanuel Berg]

Ihor Radchenko wrote:

>> AFAIU, no conversion takes place between ``Elisp formats''
>> and GMP formats. Our bignums rely on GMP for all data
>> storage and memory allocation.
>
> Thanks for the clarification! So, GMP is not as fast as
> SBCL's implementation after all. SBCL uses
> https://github.com/sbcl/sbcl/blob/master/src/code/bignum.lisp
> - a custom bignum implementation, which is clearly faster
> compared to GMP (in the provided benchmark):
>
> perf record  ~/Git/emacs/src/emacs -Q -batch -l /tmp/fib.eln
> 0.739 s
> (0.007 s for SBCL)
>
>     17.11%  emacs    libgmp.so.10.5.0      [.] __gmpz_sizeinbase
>      7.35%  emacs    libgmp.so.10.5.0      [.] __gmpz_add
>
> ^^ already >0.1 sec.

And we are not the only ones using GMP, right?

So maybe this issue in particular would be solved even more
broadly by a SBCL -> GMP transition ...

BTW, here are a bunch of new benchmarks from elisp-benchmarks
brought to CL. Ironically, as some of them were
from CL in the first place. But it is the way it goes.

  https://dataswamp.org/~incal/cl/bench/

Several benchmarks are to Emacs specific to make sense (work)
anywhere else, but there are still a few left to do.

Not that in fib.cl there are now, also brought from
elisp-benchmarks, a bunch of new implementations to try.

-- 
underground experts united
https://dataswamp.org/~incal