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

[Ihor Radchenko]

Emanuel Berg <incal@dataswamp.org> writes:

>>     ;; (declare (type (unsigned-byte 53) reps num z))
>> ...
>> Still ~3x faster compared to Elisp, but not orders
>> of magnitude.
>
> A pretty good optimization! :O
>
> But what kind of optimization is it?

The commented "optimization" is: "Hey, SBCL, do not use bignums. If ints
overflow, so be it".

> Also, what happens if you remove the OPTIMIZE declaration
> as well?

No difference.

> Still, isn't the rule of the "beat the benchmark" game to beat
> it as fast as possible?

Yes, but when CBCL is orders of magnitude faster, it indicates something
conceptually wrong in the algo. 3x is a matter of variation in the
internal details (like extra type checking in Elisp that Po Lu outlined).

-- 
Ihor Radchenko // yantar92,
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