Re: Optimize mul_var() for var1ndigits >= 8

On Tue, Aug 6, 2024, at 13:52, Dean Rasheed wrote:
> On Mon, 5 Aug 2024 at 13:34, Joel Jacobson <joel(at)compiler(dot)org> wrote:
>>
>> Noted from 5e1f3b9eb:
>> "While it adds some space on 32-bit machines, we aren't optimizing for that case anymore."
>>
>> In this case, the extra 32-bit numeric_mul code seems to be 89 lines of code, excluding comments.
>> To me, this seems like quite a lot, so I lean on thinking we should omit that code for now.
>> We can always add it later if we get pushback.
>>
>
> OK, I guess that's reasonable. There is no clear-cut right answer
> here, but I don't really want to have a lot of 32-bit-specific code
> that significantly complicates this function, making it harder to
> maintain. Without that code, the patch becomes much simpler, which
> seems like a decent justification for any performance tradeoffs on
> 32-bit machines that are unlikely to affect many people anyway.
>
> Regards,
> Dean
>
> Attachments:
> * v4-0001-Extend-mul_var_short-to-5-and-6-digit-inputs.patch
> * v4-0002-Optimise-numeric-multiplication-using-base-NBASE-.patch

I've reviewed and tested both patches and think they are ready to be committed.

Neat with the pairs variables, really improved readability a lot,
compared to my first version.

Also neat you found a way to adjust the res_weight in a simpler way
than my quite lengthy expression.

Regards,
Joel