For the specially interested, there's also this fun thread from some years ago:
http://forum.world.st/Challenge-Tuning-the-large-factorial-td3588660.html

Cheers,
Henry

On 24 May 2016, at 9:57 , Sven Van Caekenberghe <sven@stfx.eu> wrote:

I just published a short, introduction level article,

Speeding up factorial computation by changing the order of multiplications.

This is a story about a small, seemingly innocent code change that speeds up a very simple computation. It is pretty magical and serves as an example of how things are not always what they seem.

https://medium.com/concerning-pharo/speeding-up-factorial-computation-by-changing-the-order-of-multiplications-f4da3a5576da#.l3nrk9oax

Enjoy,

Sven

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