.. Copyright (c) 1998 Lawrence Livermore National Security, LLC and other
   HYPRE Project Developers. See the top-level COPYRIGHT file for details.

   SPDX-License-Identifier: (Apache-2.0 OR MIT)


.. _ch-General:

******************************************************************************
General Information
******************************************************************************


Getting the Source Code
==============================================================================

The most recent hypre distribution is available at
`https://github.com/hypre-space/hypre/tags`_ along with previous distribution
versions.

Building the Library
==============================================================================

In this and the following several sections, we discuss the steps to install and
use hypre.  First, we focus on the primary method targeting Unix-like operating
systems, such as Linux, AIX, and Mac OS X.  Then in `CMake instructions`_, we
explain an alternative approach using the CMake build system [CMakeWeb]_, which
is the best approach for building hypre on Windows systems in particular.

After unpacking the hypre tar file, the source code will be in the ``src``
sub-directory of a directory named hypre-VERSION, where VERSION is the current
version number (e.g., hypre-2.29.0).

Move to the ``src`` sub-directory to build hypre for the host platform.  The
simplest method is to configure, compile and install the libraries in
``./hypre/lib`` and ``./hypre/include`` directories, which is accomplished by:

.. code-block:: bash

   ./configure
   make

NOTE: when executing on an IBM platform ``configure`` must be executed under the
nopoe script (``./nopoe ./configure <option> ...<option>``) to force a single
task to be run on the log-in node.

There are many options to ``configure`` and ``make`` to customize such things as
installation directories, compilers used, compile and load flags, etc.

Executing ``configure`` results in the creation of platform specific files that
are used when building the library. The information may include such things as
the system type being used for building and executing, compilers being used,
libraries being searched, option flags being set, etc.  When all of the
searching is done two files are left in the ``src`` directory; ``config.status``
contains information to recreate the current configuration and ``config.log``
contains compiler messages which may help in debugging ``configure`` errors.

Upon successful completion of ``configure`` the file ``config/Makefile.config``
is created from its template ``config/Makefile.config.in`` and hypre is ready to
be built.

Executing ``make``, with or without targets being specified, in the ``src``
directory initiates compiling of all of the source code and building of the
hypre library.  If any errors occur while compiling, the user can edit the file
``config/Makefile.config`` directly then run ``make`` again; without having to
re-run configure.

When building hypre without the install target, the libraries and include files
will be copied into the default directories, ``src/hypre/lib`` and
``src/hypre/include``, respectively.

When building hypre using the install target, the libraries and include files
will be copied into the directories that the user specified in the options to
``configure``, e.g. ``--prefix=/usr/apps``.  If none were specified the default
directories, ``src/hypre/lib`` and ``src/hypre/include``, are used.

.. _config_options:

Configure Options
------------------------------------------------------------------------------

There are many options to ``configure`` to allow the user to override and refine
the defaults for any system. The best way to find out what options are available
is to display the help package, by executing ``./configure --help``, which also
includes the usage information.  The user can mix and match the configure
options and variable settings to meet their needs.

Some commonly used options include:

.. code-block:: none

   --enable-debug                 Sets compiler flags to generate information
                                  needed for debugging.
   --enable-shared                Build shared libraries.
                                  NOTE: in order to use the resulting shared
                                        libraries the user MUST have the path to
                                        the libraries defined in the environment
                                        variable LD_LIBRARY_PATH.
   --with-print-errors            Print HYPRE errors
   --with-openmp                  Use OpenMP. This may affect which compiler is
                                  chosen.
   --enable-bigint                Use long long int for HYPRE_Int (default is NO).
                                  NOTE: This option is not available for Nvidia
                                  and AMD GPUs.
   --enable-mixedint              Use long long int for HYPRE_BigInt and int for
                                  HYPRE_Int.
                                  NOTE: This option disables Euclid, ParaSails,
                                        PILUT and CGC coarsening.

The user can mix and match the configure options and variable settings to meet
their needs.  It should be noted that hypre can be configured with external BLAS
and LAPACK libraries, which can be combined with any other option.  This is done
as follows (currently, both libraries must be configured as external together):

.. code-block:: bash

   ./configure  --with-blas-lib="blas-lib-name" \
                --with-blas-lib-dirs="path-to-blas-lib" \
                --with-lapack-lib="lapack-lib-name" \
                --with-lapack-lib-dirs="path-to-lapack-lib"

The output from ``configure`` is several pages long.  It reports the system type
being used for building and executing, compilers being used, libraries being
searched, option flags being set, etc.


Make Targets
------------------------------------------------------------------------------

The make step in building hypre is where the compiling, loading and creation of
libraries occurs.  Make has several options that are called targets.  These
include:

.. code-block:: none

   help         prints the details of each target

   all          default target in all directories
                compile the entire library
                does NOT rebuild documentation

   clean        deletes all files from the current directory that are
                   created by building the library

   distclean    deletes all files from the current directory that are created
                   by configuring or building the library

   install      compile the source code, build the library and copy executables,
                    libraries, etc to the appropriate directories for user access

   uninstall    deletes all files that the install target created

   tags         runs etags to create a tags table
                file is named TAGS and is saved in the top-level directory

   test         depends on the all target to be completed
                removes existing temporary installation directories
                creates temporary installation directories
                copies all libHYPRE* and *.h files to the temporary locations
                builds the test drivers; linking to the temporary locations to
                   simulate how application codes will link to HYPRE

GPU build
------------------------------------------------------------------------------

Hypre can support NVIDIA GPUs with CUDA and OpenMP (:math:`{\ge}` 4.5). The related ``configure`` options are

.. code-block:: none

  --with-cuda             Use CUDA. Require cuda-9.0 or higher (default is
                          NO).

  --with-device-openmp    Use OpenMP 4.5 Device Directives. This may affect
                          which compiler is chosen.

The related environment variables

.. code-block:: none

   HYPRE_CUDA_SM          (default 70)

   CUDA_HOME              the CUDA home directory

need to be set properly, which can be also set by

.. code-block:: none

   --with-gpu-arch=ARG    (e.g., --with-gpu-arch='60 70')

   --with-cuda-home=DIR

When configured with ``--with-cuda`` or ``--with-device-openmp``, the memory allocated on the GPUs, by default, is the GPU device memory, which is not accessible from the CPUs.
Hypre's structured solvers can run with device memory,
whereas only selected unstructured solvers can run with device memory. See
:ref:`ch-boomeramg-gpu` for details.
Some solver options for BoomerAMG require unified (CUDA managed) memory.
To use these options add the following configure option:

.. code-block:: none

  --enable-unified-memory Use unified memory for allocating the memory
                          (default is NO).

Hypre's Struct solvers can also choose RAJA and Kokkos as the backend.
The ``configure`` options are

.. code-block:: none

  --with-raja             Use RAJA. Require RAJA package to be compiled
                          properly (default is NO).

  --with-kokkos           Use Kokkos. Require kokkos package to be compiled
                          properly(default is NO).

To run on the GPUs with RAJA and Kokkos, the options ``--with-cuda`` and ``--with-device-openmp`` are also needed,
and the RAJA and Kokkos libraries should be built with CUDA or OpenMP 4.5 correspondingly.

The other NVIDIA GPU related options include:

* ``--enable-gpu-profiling``  Use NVTX on CUDA, rocTX on HIP (default is NO)
* ``--enable-cusparse``       Use cuSPARSE for GPU sparse kernels (default is YES)
* ``--enable-cublas``         Use cuBLAS for GPU dense kernels (default is YES)
* ``--enable-curand``         Use random numbers generators on GPUs (default is YES)

Allocations and deallocations of GPU memory are expensive. Memory pooling is a common approach to reduce such overhead and improve performance.
hypre provides caching allocators for GPU device memory and unified memory,
enabled by

.. code-block:: none

  --enable-device-memory-pool  Enable the caching GPU memory allocator in hypre
                               (default is NO)


hypre also supports Umpire [Umpire]_. To enable Umpire pool, include the following options:

.. code-block:: none

  --with-umpire                Use Umpire Allocator for device and unified memory
                               (default is NO)
  --with-umpire-include=/path-of-umpire-install/include
  --with-umpire-lib-dirs=/path-of-umpire-install/lib
  --with-umpire-libs=umpire

For running on AMD GPUs, configure with

.. code-block:: none

  --with-hip              Use HIP for AMD GPUs. (default is NO)
  --with-gpu-arch=ARG     Use appropriate AMD GPU architecture

The other AMD GPU related options include:

* ``--enable-gpu-profiling``  Use NVTX on CUDA, rocTX on HIP (default is NO)
* ``--enable-rocsparse``      Use rocSPARSE (default is YES)
* ``--enable-rocblas``        Use rocBLAS (default is NO)
* ``--enable-rocrand``        Use rocRAND (default is YES)

All the options supported by CUDA are also supported with HIP. **Note that the ``--enable-bigint`` option is not supported with CUDA or HIP.**

For running on Intel GPUs, configure with

.. code-block:: none

  --with-sycl             Use SYCL for Intel GPUs. (default is NO).
  --with-sycl-target=ARG  User specifies sycl targets for AOT compilation in
                          ARG, where ARG is a comma-separated list (enclosed
                          in quotes), e.g. "spir64_gen".
  --with-sycl-target-backend=ARG
                          User specifies additional options for the sycl
                          target backend for AOT compilation in ARG, where ARG
                          contains the desired options (enclosed in
                          double+single quotes), e.g.
                          --with-sycl-target-backend="'-device
                          12.1.0,12.4.0'".

Intel oneMKL functionality is also used by default (and required for certain hypre solvers):

.. code-block:: none

  --enable-onemklsparse   Use oneMKL sparse (default is YES).
  --enable-onemklblas     Use oneMKL blas (default is YES).
  --enable-onemklrand     Use oneMKL rand (default is YES).

The SYCL backend now supports all GPU-enabled hypre functionality currently supported by CUDA/HIP except for FSAI (work in progress).
The ``--enable-bigint`` option is supported with SYCL (not supported for CUDA/HIP).

Testing the Library
------------------------------------------------------------------------------

The ``examples`` subdirectory contains several codes that can be used to test
the newly created hypre library.  To create the executable versions, move into
the ``examples`` subdirectory, enter ``make`` then execute the codes as
described in the initial comments section of each source code.


.. _CMake instructions:

CMake-based Build Instructions
==============================================================================

This section describes hypre's CMake build system, which is particularly useful for building
the code on Windows machines. CMake-based installation provides a platform-independent
build system. CMake can generate Unix and Linux Makefiles, as well as Visual Studio and
(Apple) XCode project files from the same configuration file.  In addition,
CMake also provides a GUI front end and which allows an interactive build and
installation process. For more detailed information on using CMake,
see `CMake's User Interaction Guide <https://cmake.org/cmake/help/latest/guide/user-interaction/index.html>`_.

**Note**: Not all options are currently supported when using CMake. This is an
on-going effort to support all hypre configure options.

Here are the basic steps to configure, make, and install hypre using CMake:

#. Ensure that CMake version 3.13.0 or later is installed on the system.
#. After unpacking the hypre tar file or cloning, move to the ``src`` sub-directory.
#. To build the library, run CMake on the top-level hypre source directory to
   generate files appropriate for the native build system.  To prevent writing
   over the Makefiles in hypre's configure/make system above, only out-of-source
   builds are allowed with CMake, that is, it is required to use a separate build
   directory.

   The directory ``src/cmbuild``
   is provided in the release for convenience, but
   alternative build directories may be created by the user. To configure with
   the default options:

   - Unix: From the ``src/cmbuild`` directory, type ``cmake ..``.

   - Windows Visual Studio: Set the source and build directories to ``src`` and ``src/cmbuild``,
     then click on `Configure` following by `Generate`.


#. To build the library, compile with the native build system:

   - Unix: From the ``src/cmbuild`` directory, type ``make`` or ``make -j 4``
     (for a faster parallel build with 4 threads).

   - Windows Visual Studio: Open the 'hypre' VS solution file generated by CMake
     and build the `ALL_BUILD` target.

#. To install hypre to the installation directory specified in the configuration:

   - Unix: From the ``src/cmbuild`` directory, type ``make install``.

   - Windows Visual Studio: Open the `hypre` VS solution file generated by CMake
     and build the `INSTALL` target.

   - *Note*: The default installation location is set to ``src/hypre``.
     Use the ``HYPRE_INSTALL_PREFIX`` option to change this location if desired.

Changing Default CMake Configuration Options
------------------------------------------------------------------------------

Various configuration options can be set from within CMake (see `CMake options`_).
One option is to specify these options in the command-line CMake invocation,
e.g., to enabling building of the examples:

.. code-block:: none

  cmake -DHYPRE_BUILD_EXAMPLES=ON ..

Another option is to use the CMake GUI (``ccmake`` or ``cmake-gui``) to change the default options
as appropriate, then reconfigure / generate:

- Unix: From the ``src/cmbuild`` directory, type ``ccmake ..``.

  * Change options to desired settings:

    * To set a variable, move the cursor to the variable and press enter.
    * If it is a boolean (ON/OFF) it will toggle the value.
    * If it is string or file, it will allow editing of the string.

  * Then configure (``c`` key).
  * Repeat until all values are set as desired and then generate (``g`` key).

- Windows Visual Studio: Change options, then click on `Configure` then `Generate`.

Then the re-build and re-install with the updated configuration options.

.. _CMake options:

CMake Configure Options
------------------------------------------------------------------------------

There are many options to allow the user to override and refine
the defaults for any system.  The best way to find out what options are available
is to use ``cmake``, ``cmake-gui``, or inspect using Windows Visual Studio.


Some commonly used options (default value) include:

.. code-block:: none

 HYPRE_INSTALL_PREFIX (src/hypre) Installation location.
 HYPRE_BUILD_EXAMPLES (OFF)       Compile test cases for examples of using the library.
 HYPRE_BUILD_TYPE (Release)       Sets compiler flags to generate information.
                                  needed for debugging.
 HYPRE_ENABLE_SHARED (OFF)        Build shared libraries.
 HYPRE_PRINT_ERRORS (OFF)         Print HYPRE errors.
 HYPRE_WITH_OPENMP (OFF)          Use OpenMP.

 HYPRE_ENABLE_BIGINT (OFF)        Use long long int for HYPRE_Int.
 HYPRE_ENABLE_MIXEDINT (OFF)      Use long long int for HYPRE_BigInt and int for
                                  HYPRE_Int.

GPU CMake Build Options
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Some of the commonly used options for GPU CMake builds of hypre are listed below.

* CUDA support for NVIDIA GPUs relevant options:

.. code-block:: none

 HYPRE_WITH_CUDA (OFF)            Use CUDA v9.0 or higher.
 HYPRE_CUDA_SM (70)               Target CUDA architecture.

When configured with CUDA, the memory allocated on the GPUs, by default, is the GPU device memory, which is not accessible from the CPUs.
Hypre's structured solvers can run with device memory,
whereas only selected unstructured solvers can run with device memory. See
:ref:`ch-boomeramg-gpu` for details.
Some solver options for BoomerAMG require unified (CUDA managed) memory.
To use these options turn the following option on:

.. code-block:: none

  HYPRE_ENABLE_UNIFIED_MEMORY (OFF)  Use unified memory for allocating the memory.

The other NVIDIA GPU related options include:

.. code-block:: none

 HYPRE_ENABLE_GPU_PROFILING (OFF) Use NVTX.
 HYPRE_ENABLE_CUSPARSE (ON)       Use cuSPARSE for GPU sparse kernels.
 HYPRE_ENABLE_CUBLAS (OFF)        Use cuBLAS for GPU dense kernels.
 HYPRE_ENABLE_CURAND (ON)         Use random numbers generators on GPUs.

Allocations and deallocations of GPU memory are expensive. Memory pooling is a common approach to reduce such overhead and improve performance.
hypre provides caching allocators for GPU device memory and unified memory,
enabled by

.. code-block:: none

 HYPRE_ENABLE_DEVICE_POOL (OFF)   Enable the caching GPU memory allocator in hypre


hypre also supports Umpire [Umpire]_. To enable Umpire pool, include the following options:

.. code-block:: none

 HYPRE_WITH_UMPIRE (OFF)          Use Umpire Allocator for device and unified memory.
 TPL_UMPIRE_LIBRARIES             List of absolute paths to Umpire link libraries.
 TPL_UMPIRE_INCLUDE_DIRS          List of absolute paths to Umpire include directories.

SYCL support for Intel GPUs relevant options:

.. code-block:: none

 HYPRE_WITH_SYCL (OFF)            Enable SYCL support.
 HYPRE_SYCL_TARGET                Target SYCL architecture, e.g. 'spir64_gen'.
 HYPRE_SYCL_TARGET_BACKEND        Additional SYCL backend options, e.g. '-device 12.1.0,12.4.0'.


Testing the Library with CMake Build Process
------------------------------------------------------------------------------

The ``examples`` subdirectory contains several codes that can be used to test
the newly created hypre library. The CMake option ``HYPRE_BUILD_EXAMPLES`` should
be enabled so ensure the executables in the ``examples`` subdirectory are built.

Linking to the Library
==============================================================================

An application code linking with hypre must be compiled with
``-I$PREFIX/include`` and linked with ``-L$PREFIX/lib -lHYPRE``, where
``$PREFIX`` is the directory where hypre is installed, default is ``hypre``, or
as defined by the configure option ``--prefix=PREFIX``. As noted above, if hypre
was built as a shared library the user MUST have its location defined in the
environment variable ``LD_LIBRARY_PATH``.

As an example of linking with hypre, a user may refer to the ``Makefile`` in the
``examples`` sub-directory.  It is designed to build codes similar to user
applications that link with and call hypre.  All include and linking flags are
defined in the ``Makefile.config`` file by ``configure``.


Error Flags
==============================================================================

Every hypre function returns an integer, which is used to indicate errors
during execution.  Note that the error flag returned by a given function
reflects the errors from *all* previous calls to hypre functions.  In
particular, a value of zero means that all hypre functions up to (and
including) the current one have completed successfully.  This new error flag
system is being implemented throughout the library, but currently there are
still functions that do not support it.  The error flag value is a combination
of one or a few of the following error codes:

#. ``HYPRE_ERROR_GENERIC`` -- describes a generic error
#. ``HYPRE_ERROR_MEMORY`` -- hypre was unable to allocate memory
#. ``HYPRE_ERROR_ARG`` -- error in one of the arguments of a hypre function
#. ``HYPRE_ERROR_CONV`` -- a hypre solver did not converge as expected

One can use the ``HYPRE_CheckError`` function to determine exactly which errors
have occurred:

.. code-block:: c

   /* call some HYPRE functions */
   int  hypre_ierr;
   hypre_ierr = HYPRE_Function();

   /* check if the previously called hypre functions returned error(s) */
   if (hypre_ierr)
      /* check if the error with code HYPRE_ERROR_CODE has occurred */
      if (HYPRE_CheckError(hypre_ierr,HYPRE_ERROR_CODE))

The corresponding FORTRAN code is

.. code-block:: fortran

   ! header file with hypre error codes
   include 'HYPRE_error_f.h'

   ! call some HYPRE functions
   integer  hypre_ierr
   call HYPRE_Function(hypre_ierr)

   ! check if the previously called hypre functions returned error(s)
   if (hypre_ierr .ne. 0) then
      ! check if the error with code HYPRE_ERROR_CODE has occurred
      call HYPRE_CheckError(hypre_ierr, HYPRE_ERROR_CODE, check)
      if (check .ne. 0) then

The global error flag can also be obtained directly, between calls to other
hypre functions, by calling ``HYPRE_GetError()``.  If an argument error
(``HYPRE_ERROR_ARG``) has occurred, the argument index (counting from 1) can be
obtained from ``HYPRE_GetErrorArg()``.  To get a character string with a
description of all errors in a given error flag, use

.. code-block:: c

   HYPRE_DescribeError(int hypre_ierr, char *descr);

The global error flag can be cleared manually by calling
``HYPRE_ClearAllErrors()``, which will essentially ignore all previous hypre
errors. To only clear a specific error code, the user can call
``HYPRE_ClearError(HYPRE_ERROR_CODE)``.  Finally, if hypre was configured with
``--with-print-errors``, additional error information will be printed to the
standard error during execution.


Bug Reporting and General Support
==============================================================================

Simply create an issue at `https://github.com/hypre-space/hypre/issues`_ to
report bugs, request features, or ask general usage questions.

Users should include as much relevant information as possible in their issue
report, including at a minimum, the hypre version number being used.  For
compile and runtime problems, please also include the machine type, operating
system, MPI implementation, compiler, and any error messages produced.


.. _LSI_install:

Using HYPRE in External FEI Implementations
==============================================================================

.. warning::
   FEI is not actively supported by the hypre development team. For similar
   functionality, we recommend using :ref:`sec-Block-Structured-Grids-FEM`, which
   allows the representation of block-structured grid problems via hypre's
   SStruct interface.

To set up hypre for use in external, e.g. Sandia's, FEI implementations one
needs to follow the following steps:

#. obtain the hypre and Sandia's FEI source codes,
#. compile Sandia's FEI (fei-2.5.0) to create the ``fei_base`` library.
#. compile hypre

   * unpack the archive and go into the ``src`` directory
   * do a ``configure`` with the ``--with-fei-inc-dir`` option set to the FEI
     include directory plus other compile options
   * compile with ``make install`` to create the ``HYPRE_LSI`` library in
     ``hypre/lib``.

#. call the FEI functions in your application code (as shown in Chapters
   :ref:`ch-FEI` and :ref:`ch-Solvers`)

   * include ``cfei-hypre.h`` in your file
   * include ``FEI_Implementation.h`` in your file

#. Modify your ``Makefile``

   * include hypre's ``include`` and ``lib`` directories in the search paths.
   * Link with ``-lfei_base -lHYPRE_LSI``.  Note that the order in which the
     libraries are listed may be important.

Building an application executable often requires linking with many different
software packages, and many software packages use some LAPACK and/or BLAS
functions.  In order to alleviate the problem of multiply defined functions at
link time, it is recommended that all software libraries are stripped of all
LAPACK and BLAS function definitions.  These LAPACK and BLAS functions should
then be resolved at link time by linking with the system LAPACK and BLAS
libraries (e.g. dxml on DEC cluster).  Both hypre and SuperLU were built with
this in mind.  However, some other software library files needed may have the
BLAS functions defined in them.  To avoid the problem of multiply defined
functions, it is recommended that the offending library files be stripped of the
BLAS functions.


Calling HYPRE from Other Languages
==============================================================================

The hypre library currently supports two languages: C (native) and Fortran (in
version 2.10.1 and earlier, additional language interfaces were also provided
through a tool called Babel).  The Fortran interface is manually supported to
mirror the "native" C interface used throughout most of this manual.  We
describe this interface next.

Typically, the Fortran subroutine name is the same as the C name, unless it is
longer than 31 characters.  In these situations, the name is condensed to 31
characters, usually by simple truncation.  For now, users should look at the
Fortran test drivers (``*.f`` codes) in the ``test`` directory for the correct
condensed names.  In the future, this aspect of the interface conversion will be
made consistent and straightforward.

The Fortran subroutine argument list is always the same as the corresponding C
routine, except that the error return code ``ierr`` is always last.  Conversion
from C parameter types to Fortran argument type is summarized in following
table:

   ======================  =============================
   C parameter             Fortran argument
   ======================  =============================
   ``int i``               ``integer i``
   ``double d``            ``double precision d``
   ``int *array``          ``integer array(*)``
   ``double *array``       ``double precision array(*)``
   ``char *string``        ``character string(*)``
   ``HYPRE_Type object``   ``integer*8 object``
   ``HYPRE_Type *object``  ``integer*8 object``
   ======================  =============================

Array arguments in hypre are always of type ``(int *)`` or ``(double *)``, and
the corresponding Fortran types are simply ``integer`` or ``double precision``
arrays.  Note that the Fortran arrays may be indexed in any manner.  For
example, an integer array of length ``N`` may be declared in fortran as either
of the following:

.. code-block:: fortran

   integer  array(N)
   integer  array(0:N-1)

hypre objects can usually be declared as in the table because ``integer*8``
usually corresponds to the length of a pointer.  However, there may be some
machines where this is not the case.  On such machines, the Fortran type for a
hypre object should be an ``integer`` of the appropriate length.

This simple example illustrates the above information:

C prototype:

.. code-block:: c

   int HYPRE_IJMatrixSetValues(HYPRE_IJMatrix  matrix,
                               int  nrows, int  *ncols,
                               const int *rows, const int  *cols,
                               const double  *values);

The corresponding Fortran code for calling this routine is as follows:

.. code-block:: fortran

   integer*8         matrix
   integer           nrows, ncols(MAX_NCOLS)
   integer           rows(MAX_ROWS), cols(MAX_COLS)
   double precision  values(MAX_COLS)
   integer           ierr

   call HYPRE_IJMatrixSetValues(matrix, nrows, ncols, rows, cols, values, ierr)