Re: [OctDev] arpack: eigs crash with octave 3.0.5 compiled with --enable-64

[David Bateman]

Alexander Barth wrote:
> On Fri, Jun 5, 2009 at 9:20 PM, David Bateman<address@hidden> wrote:
>   
> > Why not just use
> > octave_idx_type if the fortran logical index is 8bit with --enable-64?
> >
> >     
>
> This is in the end what I did, but I declared a macro
> octave_f77_bool_type defined as octave_idx_type.
>
> The underlying assumption is that the Fortran compiler uses the same
> amount of bytes for INTEGER and LOGICAL. I would prefer to "hide" this
> assumption behind a macro since there might be some Fortran compilers
> that handle things differently. (After all, it is quite wasteful to
> allocate 8 bytes for a variable with only two states).
>
> I looked a bit around how the different Fortran compilers handle the
> size of LOGICALs. For gfortran (with and without  -fdefault-integer-8)
> and ifort (with and without -i8), the size of LOGICALs will always be
> the size of INTEGER. However, with pgf90, the compiler option -i8,
> leaves the size of LOGICALs to 4 bytes. Only the option -i8storage
> allocates 8 bytes for INTEGER and LOGICAL.
>
> This reminds me also a bit of the assumption that size of a pointer
> will always be the same as the size of an int in C. Such assumption is
> the classical problem when porting a program to 64-bit CPU.
>
> Cheers,
> Alex
>   
Grrr, then we need an autoconf test that probes the number of bytes in a 
fortran logical type and sets your macro appropriately...

D.

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