Why not use regular rejection sampling when `limit` is known at compile-time.
Does fastrange[1] have fewer rejections due to any excess random bits[2]?
Fastrange is slightly biased because, as Steve Canon observes in that Swift PR, it is just Knuth’s multiplicative reduction. The point of this post is that it’s possible to simplify Lemire’s nearly-divisionless debiasing when the limit is known at compile time.
fanf2|11 months ago
Fastrange is slightly biased because, as Steve Canon observes in that Swift PR, it is just Knuth’s multiplicative reduction. The point of this post is that it’s possible to simplify Lemire’s nearly-divisionless debiasing when the limit is known at compile time.
I previously experimented with really-divisionless debiasing but I was underwhelmed with the results https://dotat.at/@/2022-04-20-really-divisionless.html
aqrit|11 months ago
I was thinking naive: mask off unwanted bits then reject any value above the limit.
It would seem like https://c-faq.com/lib/randrange.html would also move the multiply --or divide by constant-- out of the loop.