Strange counter-performance in an alternative `decimalLength9` function

[Basile B.]

On Wednesday, 26 February 2020 at 22:07:30 UTC, Johan wrote:
> On Wednesday, 26 February 2020 at 00:50:35 UTC, Basile B. wrote:
>> [...]
>
> Hi Basile,
>   I recently saw this presentation: 
> https://www.youtube.com/watch?v=Czr5dBfs72U

Andrei made a talk about this too a few years ago.

> It has some ideas that may help you make sure your measurements 
> are good and may give you ideas to find the performance 
> bottleneck or where to optimize.
> llvm-mca is featured on godbolt.org: 
> https://mca.godbolt.org/z/YWp3yv
>
> cheers,
>   Johan