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Re: Sieve of Erastosthenes optimized to the max

From	Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups	comp.lang.c++
Subject	Re: Sieve of Erastosthenes optimized to the max
Date	2024-05-21 19:06 -0700
Organization	A noiseless patient Spider
Message-ID	<86r0duwqgg.fsf@linuxsc.com> (permalink)
References	(16 earlier) <utoh9d$6lrr$1@raubtier-asyl.eternal-september.org> <utq0ag$hvrl$3@dont-email.me> <utq0os$ibqn$1@raubtier-asyl.eternal-september.org> <utq11p$icmm$1@dont-email.me> <v25c87$1ld9m$1@dont-email.me>

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Vir Campestris <vir.campestris@invalid.invalid> writes:

> I've been playing with this.  Has it really been this long?  I
> ought to have more time than this...  [...]
>
> I missed Tim's Mod 30 trick, and that might well help.  But I
> think I'm bored with this.  It would save a lot of memory, but
> the extra computation might make it slower.

Two comments.  Using the mod 30 encoding can be speed competitive
with simpler encodings.  The second comment is, it isn't just
that less memory is used, but that more primes can be found.
Bonita brags about how fast some code is, but it's an apples
and oranges comparison - that code doesn't do the job because
it runs into a memory limit way sooner than using a mod 30
encoding, and trying to run past that limit would make the
code R E A L L Y  S L O W.

> Maybe I'll try one day ;)

I hope you do.  If you have some difficulty seeing how to
avoid the seeming speed penalties, feel free to ask, I am
happy to help.

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Thread

Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-05-16 17:28 +0100
  Re: Sieve of Erastosthenes optimized to the max Ben Bacarisse <ben@bsb.me.uk> - 2024-05-16 21:40 +0100
  Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-21 19:06 -0700
    Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-05-30 12:32 +0100
      Re: Sieve of Erastosthenes optimized to the max Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-30 14:17 +0200
      Re: Sieve of Erastosthenes optimized to the max Paavo Helde <eesnimi@osa.pri.ee> - 2024-05-30 19:55 +0300
        Re: Sieve of Erastosthenes optimized to the max Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-31 10:17 +0200
          Re: Sieve of Erastosthenes optimized to the max Paavo Helde <eesnimi@osa.pri.ee> - 2024-05-31 20:52 +0300
      Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-05-30 22:17 -0700
        Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-06-01 21:07 +0100
          Re: Sieve of Erastosthenes optimized to the max Richard Damon <richard@damon-family.org> - 2024-06-01 20:43 -0400
          Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-02 03:23 -0700
            Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-02 19:50 -0700
              Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-06-18 20:56 +0100
                Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-18 17:34 -0700
                Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-06-30 21:47 +0100
                Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-01 23:20 -0700
                Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-07-02 21:24 +0100
                Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-07-03 11:25 +0100
                Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-15 06:15 -0700
                Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-20 07:41 -0700
                OT: Re: Sieve of Erastosthenes optimized to the max Vir Campestris <vir.campestris@invalid.invalid> - 2024-07-25 12:46 +0100
                Re: Sieve of Erastosthenes optimized to the max Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-23 07:34 -0700

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