[Trilinos-Users] New and modified MPI configure options

[Willenbring, James M]

IMPORTANT:

With the latest commit, many MPI configure options have changed.  These
changes
apply to the development branch, as well as the new Trilinos 3.01 minor
release.
The 3.01 release should occur within 24 hours.
However, these changes have not been incorporated into the Trilinos 3.0 
release.

The primary purpose of the changes was to make the specification of
MPI-related
options more straight-forward.  The changes should also reduce the number of
options that need to be specified on many machines.

-----------------------------------
Here is an overview of the changes:
-----------------------------------

--enable-mpi no longer sets the default compilers to be mpiCC, mpicc and
mpif77.
Rather, MPI compilers are found in the same way that serial compilers are - 
check for CXX, CC, and F77, if not specified, check for a set list of
compilers
and use the first one that is found.  (Use the other mpi-related options
listed
below to specify mpi-libs, mpi-incdir and mpi-libdir, if necessary.)

--with-mpi-compilers behaves the way that --enable-mpi used to (ie sets
default
MPI compilers.  

--with-mpi-cxx, --with-mpi-cc, and --with-mpi-f77 no longer are valid
options,
simply use CXX, CC, and F77 instead.

---------------------------------------------------
Here is an updated list of the MPI-Related Options:
---------------------------------------------------

--enable-mpi 

Enables MPI mode. Defines HAVE_MPI in the (Package)_Config.h file. Will test

for the ability to preprocess the MPI header file and may test ability to
link 
with MPI.  This option is rarely necessary as many of the below options also

turn MPI on.  


--with-mpi-compilers

Sets the MPI c++ compiler = mpicxx (or mpiCC if mpicxx not available), 
the MPI C compiler = mpicc and the MPI Fortran compiler = mpif77.  
Automatically enables MPI mode.  To use compilers other than these, 
specify mpi locations with the below options.  If none of these options 
are necessary, don't forget to use --enable-mpi.  CXX, CC, and F77 may also 
have to be set if autoconf does not choose the correct compilers by default.

NOTE: This option performs the same function that --enable-mpi used to
perform 
(ie setting default MPI compilers).  

--with-mpi=MPIROOT 

Specify the MPI root directory. Automatically enables MPI mode. 


--with-mpi-libdir=DIR 

Specify the MPI libraries location. Defaults to MPIROOT/lib if --with-mpi 
is specified. If multiple directories must be specified, try 
--with-ldflags="-L<dir1> -L<dir2>" instead. 


--with-mpi-libs="LIBS" 

Specify the MPI libraries. Defaults to "-lmpi" if either --with-mpi or 
--with-mpi-libdir is specified.


--with-mpi-incdir=DIR

Specify the MPI include files location. Defaults to MPIROOT/include if 
--with-mpi is specified. If multiple directories  must be specified, try 
--with-cppflags="-I<dir1> -I<dir2>" instead.

These options have also been updated on the configure --help screens for
each
package.

please direct any questions to jmwille@sandia.gov