Charles Greathouse on Thu, 25 Oct 2012 22:17:09 +0200


[Date Prev] [Date Next] [Thread Prev] [Thread Next] [Date Index] [Thread Index]

Re: forprime in 32bit is 50x slower if p>2^32


Maybe I'll set up my build script to make both 32- and 64-bit, then. I
haven't tested any of my 32-bit code, though I usually write code in
both forms when convenient.

Charles Greathouse
Analyst/Programmer
Case Western Reserve University

On Thu, Oct 25, 2012 at 3:59 PM, Bill Allombert
<Bill.Allombert@math.u-bordeaux1.fr> wrote:
> On Thu, Oct 25, 2012 at 03:34:46PM -0400, Charles Greathouse wrote:
>> > Maybe we could at least replace 210 by something larger.
>>
>> Maybe. Maybe even use a small sieve if the numbers are large enough
>> (not in this case...), say of length 4 log x (98% likely to contain
>> the next prime).
>>
>> > If you had to debug ellheegner in 32bit, you might change your mind.
>> >
>> > Beside ARM users are stuck with 32bit for some years still.
>>
>> Yes, it's bad for Windows and ARM users (as well as legacy users). I
>> do think it would be nice, but I have a hard time seeing how it could
>> be fit in. Even if I had a machine to test with I owe Karim an
>> implementation of forfactored() first.
>
> Well, I do not mean to insist, but I need to clarify that it is usually very
> easy to build 32bit binaries on a 64bit system.  There is no need for a new
> machine or a new OS or even a new compiler, only a 32bit libc. Just do
> CC='gcc -m32' ./Configure.
>
> Cheers,
> Bill.