README file

These are the instruction for compiling IroIro code


Required dependences:
---------------------

* GSL GNU scientific library             [http://www.gnu.org/s/gsl/]
* GMP GNU multiple precision             [http://www.gmplib.org]
* MPFR Multiple precision floating point [http://www.mpfr.org/]


Configure options
=================

Use 
./configure --help 
for a list of all options

The two most relevant ones are
--enable-improved  Turns on faster Wilson kernels
--enable-mpi       Turns on mpi support on multicore pc

MPI is automatic on Hitachi and IBM platforms.

Simple compilation
==================

For a single core run just compile with

./configure
make 

Default optimization level is \c -O3 .

To override compiler flags just use the CXXFLAGS="..." command,
remembering that the following flags are necessary for correct configuration:

-q64 -qlanglvl=stdc99 -qrtti=type

If you have a multicore platform you can speedup the compilation time
by using the command

make -j #processes

Where #processes should be about 1.5x the number of your cores 
to keep all of them busy.


Compilation on AIX Hitachi SR16000 machine
===================================================
Use the following simple lines
 
./configure 
make

Compilation on AIX IBM Blue Gene Q machine
===================================================
Same as Hitachi SR16000, use the following lines
 
./configure 
make


Compilation with INTEL compiler (icpc)
===================================================
The configure will automatically look for INTEL compiler.
If it is found in the path, icpc will be used in compilation.

Use CXXFLAGS="..." during configure to setup your preferred flags
(this will override every default flag).

Note: The compiler must be at least version 12.0.5

Use this line to compile on MPI general machine
===============================================
./configure --enable-mpi 

Run with mpirun -n #nodes #executable


Testing and debugging
=====================
valgrind --leak-check=yes --log-file=valgrind.log ./hmc


Verbosity
=========

In order to set the verbosity of executable files during runtime
use the variable code_verbosity in configuration.

Example
./configure code_verbosity=5

set maximum verbosity. Allowed values from 0 to 5. Default is 1.


Installing required dependences
==============

Required libraries

* The Gnu Scientific Library (GSL) is required during compilation 
  of Domain Wall routines. 
* The Gnu Multiple Precision (GMP) and the MPFR libraries are required 
  for Remez algorithm routines, in rational approximation of functions.  

On AIX the default development environment is in 32 bit mode, 
but IroIro compilation forces 64 bit mode. 
In this case please check that libraries are installed in 64 bit 
version otherwise clash on library names could occur. 

If you are compiling the library in a custom installation 
with XLC on AIX please setup the environment variable 

  OBJECT_MODE=64
  
(use 'export OBJECT_MODE=64' in bash shell), or use

 -q64

among compilation flags (CFLAGS="-q64").

For non standard installation configure assumes that GSL can also reside in
~/gsl/ directory, so that you can just create a symbolic link 
to your preferred build. 
The same applies to ~/gmp and ~/mpfr