octave: Compiling Octave with 64-bit Indexing
E.3 Compiling Octave with 64-bit Indexing
=========================================
Note: the following only applies to systems that have 64-bit pointers.
Configuring Octave with ‘--enable-64’ cannot magically make a 32-bit
system have a 64-bit address space.
On 64-bit systems, Octave is limited to (approximately) the following
array sizes when using the default 32-bit indexing mode:
double: 16 GB
single: 8 GB
uint64, int64: 16 GB
uint32, int32: 8 GB
uint16, int16: 4 GB
uint8, int8: 2 GB
In each case, the limit is really (approximately) 2^{31} elements
because of the default type of the value used for indexing arrays
(signed 32-bit integer, corresponding to the size of a Fortran INTEGER
value).
Trying to create larger arrays will produce the following error:
octave:1> a = zeros (1024*1024*1024*3, 1, 'int8');
error: memory exhausted or requested size too large
for range of Octave's index type --
trying to return to prompt
You will obtain this error even if your system has enough memory to
create this array (4 GB in the above case).
To use arrays larger than 2 GB, Octave has to be configured with the
option ‘--enable-64’. This option is experimental and you are
encouraged to submit bug reports if you find a problem. With this
option, Octave will use 64-bit integers internally for array dimensions
and indexing. However, all numerical libraries used by Octave will
*also* need to use 64-bit integers for array dimensions and indexing.
In most cases, this means they will need to be compiled from source
since most (all?) distributions which package these libraries compile
them with the default Fortran integer size, which is normally 32-bits
wide.
The following instructions were tested with the development version
of Octave and GCC 4.3.4 on an x86_64 Debian system.
The versions listed below are the versions used for testing. If
newer versions of these packages are available, you should try to use
them, although there may be some differences.
All libraries and header files will be installed in subdirectories of
‘$prefix64’ (you must choose the location of this directory).
• BLAS and LAPACK (<http://www.netlib.org/lapack>)
Reference versions for both libraries are included in the reference
LAPACK 3.2.1 distribution from <netlib.org>.
− Copy the file ‘make.inc.example’ and name it ‘make.inc’. The
options ‘-fdefault-integer-8’ and ‘-fPIC’ (on 64-bit CPU) have
to be added to the variable ‘OPTS’ and ‘NOOPT’.
− Once you have compiled this library make sure that you use it
for compiling Suite Sparse and Octave. In the following we
assume that you installed the LAPACK library as
$prefix64/lib/liblapack.a.
• QRUPDATE (<http://sourceforge.net/projects/qrupdate>)
In the ‘Makeconf’ file:
− Add ‘-fdefault-integer-8’ to ‘FFLAGS’.
− Adjust the BLAS and LAPACK variables as needed if your 64-bit
aware BLAS and LAPACK libraries are in a non-standard
location.
− Set ‘PREFIX’ to the top-level directory of your install tree.
− Run ‘make solib’ to make a shared library.
− Run ‘make install’ to install the library.
• SuiteSparse (<http://www.cise.ufl.edu/research/sparse/SuiteSparse>)
Pass the following options to ‘make’ to enable 64-bit integers for
BLAS library calls. On 64-bit Windows systems, use
‘-DLONGBLAS="long long"’ instead.
CFLAGS='-DLONGBLAS=long'
CXXFLAGS='-DLONGBLAS=long'
The SuiteSparse makefiles don’t generate shared libraries. On some
systems, you can generate them by doing something as simple as
top=$(pwd)
for f in *.a; do
mkdir tmp
cd tmp
ar vx ../$f
gcc -shared -o ../${f%%.a}.so *.o
cd $top
rm -rf tmp
done
Other systems may require a different solution.
• ARPACK (http://forge.scilab.org/index.php/p/arpack-ng/)
− Add ‘-fdefault-integer-8’ to ‘FFLAGS’ when running configure.
− Run ‘make’ to build the library.
− Run ‘make install’ to install the library.
• ATLAS instead of reference BLAS and LAPACK
Suggestions on how to compile ATLAS would be most welcome.
• GLPK
• Qhull (<http://www.qhull.org>)
Both GLPK and Qhull use ‘int’ internally so maximum problem sizes
may be limited.
• Octave
Octave’s 64-bit index support is activated with the configure
option ‘--enable-64’.
./configure \
LD_LIBRARY_PATH="$prefix64/lib" \
CPPFLAGS="-I$prefix64/include" LDFLAGS="-L$prefix64/lib" \
--enable-64
You must ensure that all Fortran sources except those in the
‘liboctave/cruft/ranlib’ directory are compiled such that INTEGERS
are 8-bytes wide. If you are using gfortran, the configure script
should automatically set the Makefile variable ‘F77_INTEGER_8_FLAG’
to ‘-fdefault-integer-8’. If you are using another compiler, you
must set this variable yourself. You should NOT set this flag in
‘FFLAGS’, otherwise the files in ‘liboctave/cruft/ranlib’ will be
miscompiled.
• Other dependencies
Probably nothing special needs to be done for the following
dependencies. If you discover that something does need to be done,
please submit a bug report.
− pcre
− zlib
− hdf5
− fftw3
− cURL
− GraphicsMagick++
− OpenGL
− freetype
− fontconfig
− fltk
Info Catalog
octave: Running Configure and Make
octave: Installation
octave: Installation Problems