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High Performance Conjugate Gradient Benchmark (HPCG)
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:Author: Jack Dongarra and Michael Heroux and Piotr Luszczek
:Revision: 2.4
:Date: June 3, 2014

============
Introduction
============

HPCG is a software package that performs a fixed number of symmetric
Gauss-Seidel preconditioned conjugate gradient iterations using double
precision (64 bit) floating point values.  Integer arrays have global and local
scope (global indices are unique across the entire distributed memory system,
local indices are unique within a memory image).  Integer data for global/local
indices have three modes:

* 32/32 - global and local integers are 32-bit
* 64/32 - global integers are 64-bit, local are 32-bit
* 64/64 - global and local are 64-bit.

These various modes are required in order to address sufficiently big problems
if the range of indexing goes above 2^31 (roughly 2.1B), or to conserve storage
costs if the range of indexing is less than 2^31.

The  HPCG  software  package requires the availibility on your system of an
implementation of the  Message Passing Interface (MPI). An implementation
compliant with MPI version 1.1 is sufficient.

============
Installation
============

See the file ``INSTALL`` in this directory.

=============
Documentation
=============

The source code documentation can be generated with a Doxygen (version 1.8 or
newer). In this directory type::

    doxygen tools/hpcg.dox

Doxygen will then generate various output formats in the ``out`` directory.

======
Tuning
======

See the file ``TUNING`` in this directory.

====
Bugs
====

Known problems and bugs with this release are documented in the file
``BUGS``.

===================
Further information
===================

Check out  the website  http://software.sandia.gov/hpcg for the latest
information.