Hello,
> Also, the alternate implementation should not change the result, so
> something looks amiss in your version. Moreover, I'm unclear how to
> implement an overflow multiply with the safe no overflow version.
(snip)
I made an honest mistake. I had assumed the modulo number of Knuth's LCG
is (2 ^ 64 - 1).
BTW, I found other overflow issue.
In pseudorandom_perm(), `modular_multiply() + (key >> LCG_SHIFT)` may
overflow if the result of modular_multiply() is large. Therefore, I've
improved it.
Also, I've simplified Step 5 in modular_multiply().
I attached pgbench-prp-func-9.patch.
Best regards,
