ifort -i8 -r8 options

Barry Smith bsmith at mcs.anl.gov
Tue Jul 14 10:51:23 CDT 2009

   Mumps and hypre do not currently support using 32 bit integer  
indices, though the MUMPS folks say they plan to support it eventually.

   Changing PETSc to convert all 64 bit integers to 32 bit before  
passing to MUMPS and hypre is a huge project and we will not be doing  
You need to lobby the MUMPS and hypre to properly support 64 bit  
integers if you want to use them in that mode.

   Unless you are solving very large problems it seems you should be  
able to use the -r8 flag but not the -i8 flag.


On Jul 14, 2009, at 10:42 AM, Andreas Grassl wrote:

> Hello,
> trying external packages (especially MUMPS and HYPRE) I noticed,  
> that PETSc has
> to be compiled with-32-bit-indices and this is giving me some  
> problems because
> all Diana-routines from which I'm reading out my data are compiled  
> with ifort
> -i8 -r8 flags and I run into trouble matching together 64-bit  
> integers from
> Diana to 32-bit PetscInt's.
> Recompiling Diana without the ugly flags is no alternative.
> Wrapping some casting routines around the arrays seems doable but  
> doesn't seem
> to me the cleanest solution.
> Does anybody have an advice how to handle the problem?
> Cheers,
> ando
> -- 
> /"\                               Grassl Andreas
> \ /    ASCII Ribbon Campaign      Uni Innsbruck Institut f. Mathematik
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> / \                               +43 (0)512 507 6091

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