Re: isprime() runtime jump between 10^18 and 10^20?

Aurel Page on Tue, 06 Jan 2026 21:24:11 +0100

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Re: isprime() runtime jump between 10^18 and 10^20?

To: pari-users@pari.math.u-bordeaux.fr
Subject: Re: isprime() runtime jump between 10^18 and 10^20?
From: Aurel Page <aurel.page@normalesup.org>
Date: Tue, 6 Jan 2026 21:24:07 +0100
References: <2c3f147fba43433a547a56ba16b42e42@stamm-wilbrandt.de> <1fea967c-e61d-42ee-b9e3-4b990e4fea1e@normalesup.org> <b5f32074befc3114eaaea0bd9e3a730e@stamm-wilbrandt.de>

On 06/01/2026 20:59, hermann@stamm-wilbrandt.de wrote:

Thanks for the explanation. But long is a signed type, shouldn't thetransition from long to t_INT happen at +2^63?

Indeed, I meant ulong. For primality testing the sign can be (and istherefore) discarded.


Cheers,
Aurel

References:
- isprime() runtime jump between 10^18 and 10^20?
  - From: hermann@stamm-wilbrandt.de
- Re: isprime() runtime jump between 10^18 and 10^20?
  - From: Aurel Page <aurel.page@normalesup.org>
- Re: isprime() runtime jump between 10^18 and 10^20?
  - From: hermann@stamm-wilbrandt.de

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