[petsc-users] PetscTableCreateHashSize

[Satish Balay]

I've added up to INT_MAX

Let us know if that doesn't work.

Satish

On Mon, 9 Jan 2017, Kong, Fande wrote:

> Thanks a lot Satish!
> 
> Like Jed said, it would be better if we could come up an algorithm for
> automatically computing a hash size for a given n.  Otherwise, we  may need
> to  add more entries to the lookup again in the future.
> 
> Fande,
> 
> On Mon, Jan 9, 2017 at 2:14 PM, Satish Balay <balay at mcs.anl.gov> wrote:
> 
> > On Mon, 9 Jan 2017, Jed Brown wrote:
> >
> > > Satish Balay <balay at mcs.anl.gov> writes:
> > > > Sure - I'm using a crappy algorithm [look-up table] to get
> > > > "prime_number_close_to(1.4*sz)" - as I don't know how to generate
> > > > these numbers automatically.
> > >
> > > FWIW, it only needs to be coprime with PETSC_HASH_FACT.
> >
> > Not sure I understand - are you saying coprime requirement is easier
> > satisfy than a single prime?
> >
> > I had switched this code to use double-hasing algorithm - and the
> > requirement here is - the table size be a prime number. [so I'm
> > attempting to estimate a prime number suitable for the table size]
> >
> > I pushed the following
> > https://urldefense.proofpoint.com/v2/url?u=https-3A__
> > bitbucket.org_petsc_petsc_commits_d742c75fd0d514f7fa1873d5b10984
> > bc3f363031&d=DQIBAg&c=54IZrppPQZKX9mLzcGdPfFD1hxrcB_
> > _aEkJFOKJFd00&r=DUUt3SRGI0_JgtNaS3udV68GRkgV4ts7XKfj2opmi
> > CY&m=nkPXHuaxZeHPzOteY25j_Dptk5XyWiqwzaJbEwI5uWY&s=
> > eOjfGCXP3g18VLYhXY5xrlOr7AFn7o3G_YrYVo8Rw8Y&e=
> >
> > Satish
> >
>