[petsc-users] PETSC_INT 32bits / 64 bits problem

[Barry Smith]

  Configure PETSc with --with-64-bit-indices  just leave BLAS LAPACK alone it can use the standard blas and lapack.

   Barry

On Jul 29, 2013, at 2:22 PM, Lu Qiyue <luqiyue at gmail.com> wrote:

> Dear All:
> 
> I am solving a huge system of AX=b, Matrix A is a sparse matrix but its number of non-zeros has been out of range of the upper limit of PETSC_INT (4 bytes). 
> 
> In the online documents
> http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Sys/PetscInt.html
> It shows:
> Its size can be configured with the option --with-64-bit-indices - to be either 32bit or 64bit [default 32 bits int]. 
> Also, in the document:
> http://www.mcs.anl.gov/petsc/petsc-current/include/petscsys.h.html#PetscInt
> Looks need to configure BLAS and LAPACK lib with 64 bits options as well.
> 
> If I just change the PETSC_INT declaration in the driver to LONG INT, warnings prompt out when calling functions which used PETSC_INT data as its parameters.
> 
> Should I recompile (re-install) PETSC to add the 64 bits configurations? And for BLAS and LAPACK libs? Or, is there any other solutions?
> 
> Thanks
> 
> Qiyue Lu