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Re: [PrimeNumbers] building factoring routines

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  • Phil Carmody
    ... Now I ve decomissioned my PPro/200, I don t have a machine slow enough to measure my native double reimplimantation of Lenstra s (LIP) version of Shanks
    Message 1 of 4 , Jun 3, 2006
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      --- Jud McCranie <j.mccranie@...> wrote:
      > At 09:42 AM 6/3/2006, hecht wrote:
      > >I can factor numbers in the 12 digit range pretty quickly now, but it still
      > >took over a minute to find a factor of 10^15 + 3.
      > >
      > >Why so long? It takes me 24 ms (Pollard Rho, HIT library, PIII 700 MHz)
      >
      > For numbers in that range (fewer than 64 bits), I wouldn't use HIT or any
      > other such package. Just use the native data types. Also, Shank's method
      > is probably better for that application than Pollard's method. My program
      > on a 2.4 GHz factors 10^15+3 in 0.01 second.

      Now I've decomissioned my PPro/200, I don't have a machine slow
      enough to measure my native double reimplimantation of Lenstra's
      (LIP) version of Shanks' SQUFOF on that number! (And I gave away
      my ARM dev board yesterday - that would have been really slow.)

      However, I found two Sparcs, with their notoriously underpowered FPUs,
      in America, and indeed they are slow enough for it to be measurable:
      SunBlade100 - 0.007s
      SunUltra5 - 0.010s
      (no idea what clock speed they may be).

      Paul - may I post the code? It's Lenstra's copyright, but you seem
      to be the guardian of it presently?

      Phil

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