El 07/06/2025 a las 10:32, Peter Dimov via Boost escribió:
Joaquin M López Muñoz wrote:
El 07/06/2025 a las 1:33, Peter Dimov via Boost escribió:
Joaquin M López Muñoz wrote:
Hi,
As per feedback given here:
https://lists.boost.org/Archives/boost//2025/05/259548.php
I've experimented with the hash production scheme suggested by Kostas, where h_{i+1} is calculated as h_i * 6364136223846793005 mod 2^64: Where does this multiplier come from? This is the constant suggested by Kostas. A search on the Internet suggests this is used in connection with so-called PCG algorithms. Wikipedia lists it as "MMIX by Donald Knuth", 6364136223846793005 * x + 1442695040888963407 mod 2^64.
This is an LCG multiplier (used with b != 0), so it's not clear whether it would be "good" for an MCG (b == 0).
For multipliers my go-to reference is Vigna and Steele,https://arxiv.org/pdf/2001.05304.
For MCG mod 2^64, it gives 0xf1357aea2e62a9c5 as the "good multiplier".
I can use that, but I'm currently more concerned about the potential impact on performance, which is allegedly independent of the particular constant chosen. Joaquin M Lopez Munoz