Ciao,
Il 2021-11-08 18:57 Marco Bodrato ha scritto:
I got inspired by a piece of code that Seth Troisi sent a couple of
years ago and I wrote a gmp_pi_ui(n) function with two variants, a
trivial one (it calls gmp_primesieve) and an implementation of the
Legendre strategy.
I attach it for comments. Compiled with -DMAIN it prints the number of
primes up to increasing powers of two. On my computer, with small
ranges it is slower than GP/Pari, for large ranges, it is faster...
I checked the results against https://oeis.org/A007053 and
https://oeis.org/A006880 up to 2^47. Everything seems correct... Of
course, for "large" (>2^32) values it is a slow function.
It currently takes an ui for the argument. But it should not be
impossible to implement it also for values larger than 32 bits on
32-bits CPUs... Is it worth trying?
Ĝis,
m
--
http://bodrato.it/papers/
_______________________________________________
gmp-devel mailing list
gmp-devel@gmplib.org
https://gmplib.org/mailman/listinfo/gmp-devel
