Problem with gmp_randinit_set

Marco Bodrato bodrato at
Sun Feb 19 19:41:05 UTC 2017


Il Sab, 18 Febbraio 2017 1:47 pm, Pedro Gimeno ha scritto:
> Niels Möller wrote, On 2017-02-18 08:24:

>> Do we want to generate same sequences as other mersenne twister
>> implementations, or is it only an issue of whether or not we
>> want to change seeding and generate different sequences
>> than earlier GMP versions?

> The latter.

As Niels showed, it is not too complex to rewrite the modular
exponentiation currently used to seed the Mersenne Twister using only the
mpn layer.

The problem is that Niels' code, mine, and the current mpz code... do all
"reduce" modulo (2^19937-20023) obtaining some non-canonical

If we "do not want to generate different sequences than earlier GMP", we
will have to mimic current behaviour, even in the corner cases...

Is it worth doing?

If the small patch already pushed is enough to heal the _initset, _reseed
problem, we might dec


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