Re: Octave 5.2.0 release

[John W. Eaton]

On 1/16/20 8:14 PM, Nicholas Jankowski wrote:
>     One thing you can try is running the commands from the wiki example
>     (there I recently figured out how to test 64-bit indexing with only 8 GB
>     main memory available):
>
> is there any kind of 'is compiled with 64bit indexing'

We have a way to detect that:

  __octave_config_info__ ("ENABLE_64")

By default, that is true on a systems that have 64-bit pointers (so it 
will be true for both the w64 and w64-64 Windows builds).

But having 64-bit indexing for arrays is separate from having the 
Fortran libraries (BLAS, LAPACK, QUADPACK, DASSL, DASRT, DASPK, LSODE) 
and other code that depends on them like SuiteSparse, built with 64-bit 
integers for indexing.  On most modern systems, the Fortran INTEGER data 
type is a signed 32-bit integer.  This is true for Windows and Linux by 
default.  The w64-64 Windows build uses an option to enable 64-bit 
Fortran INTEGERS when building these libraries.

It looks like we currently don't have anything in __octave_config_info__ 
to indicate that Octave was compiled to expect and use 64-bit Fortran 
integers but we should be able to easily add something based on the 
OCTAVE_SIZEOF_F77_INT_TYPE found in config.h.

> flag such that a 
> test could be written where if true it runs a quick:
>
>  >> a = zeros (1024*1024*1024*3, 1, 'int8');
>
> during the test suite?

That should work on any 64-bit system unless you specifically disable 
64-bit indexing.

jwe