[petsc-users] cannot compile/use ml with 64 bit integers

[Barry Smith]

  Though ml does support 64 bit integers for long vectors they do it in a fundamentally different way than PETSc; only certain integer data is stored in 64 bit form while most integer values are stored in 32 bit integers. In PETSc we manage all integers as either 32 or 64 bit so mixing the two libraries in this case is not possible without a huge amount of work.  Sorry about this.

   You might consider using hype’s Boomeramg or PETSc’s GAMG algebraic multigrid solvers instead, both of which can be used with 64 bit indices.

   Barry

On Feb 21, 2014, at 1:15 PM, Xiangdong <epscodes at gmail.com> wrote:

> Hello everyone,
> 
> When I compile petsc with options -with-64-bit-indices and  ml packages, I got the error like this: "Cannot use ml with 64 bit integers, it is not coded for this capability".
> 
> If I want to use ml as a preconditioner for long vectors (> 2 billions), is there any solution?
> 
> Thank you.
> 
> Best,
> Xiangdong 
>