Bill Allombert on Thu, 26 Jan 2012 12:01:30 +0100 |
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Re: questions |
On Thu, Jan 26, 2012 at 01:42:22AM -0800, John W. Nicholson wrote: > OK, I have some questions. > > Let us start with the following quote: > " > 3.13.26 primelimit: gp precomputes a list of all primes less than primelimit at initialization > time. These are used by many arithmetic functions, usually for trial division purposes. If you do > not plan to invoke any of them, you can just set this to 1. The maximal value is a little less than > 2^32 (resp 2^64) on a 32-bit (resp. 64-bit) machine. > Since almost all arithmetic functions eventually require some table of prime numbers, PARI > currently guarantees that the rst 6547 primes, up to and including 65557, are precomputed, even > if primelimit is 1. > The default value is 500k. > " > Q: > What is the true value for "a little less 2^32 (resp 2^64) on a 32-bit (resp. 64-bit) machine"? > And, see what it did below? > " > ? primelimit=2^64 > %1 = 18446744073709551616 You should use default to change primelimit in GP: ? default(primelimit,2^64) But in any case, it is not practically possible to go much higher than 10^10 due to space/time constraint. Cheers, Bill.