Re: [PATCH] Re: Bignum performance (was: Shrinking the C core)

[Ihor Radchenko]

Emanuel Berg <incal@dataswamp.org> writes:

>> It tells that normal int operations are much, much faster
>> compared to bigint. So, your benchmark is rather esoteric if
>> we consider normal usage patterns.
>
> Didn't you provide a whole set of benchmarks with an
> approximated gain of 10%? Maybe some esoteric nature is
> built-in in the benchmark concept ...

The main problem your benchmark demonstrated is with bignum.
By accident, it also revealed slight inefficiency in vector allocation,
but this inefficiency is nowhere near SBCL 0.007 sec vs. Elisp 2.5 sec.

In practice, as more generic benchmarks demonstrated, we only had 10%
performance hit. Not something to claim that Elisp is much slower
compared to CL.

It would be more useful to compare CL with Elisp using less specialized
benchmarks that do not involve bignums. As Mattias commented, we do not
care much about bignum performance in Elisp - it is a rarely used
feature; we are content that it simply works, even if not fast, and the
core contributors (at least, Mattias) are not seeing improving bignums
as their priority.

-- 
Ihor Radchenko // yantar92,
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