This document provides information about the Coarray ICAR program.

• Installation and testing
• System requirements
• Generating documentation

The first execution creates three *.dat files and takes about 30 minutes usin 4 cores inside a Lubuntu Linux virtualmachine. Subsequent executions will read the *.dat files and executive run much faster than the first run.

$ cd coarray_icar/src/tests 
$ export COMPILER=gnu
$ make USE_ASSERTIONS=.true.
$ cafrun -n 4 ./test-ideal

which will run the test-ideal executable program in 4 images.

Compile and test coarray in a bash shell on a Linux, macOS, or the Windows Subsystem for Linux:

  cd <path-to-coarray-icar>  # Change directory to the coarray_icar source directory
  mkdir build            # create the build directory
  cd build
  FC=<compiler-command> cmake .. -DCMAKE_INSTALL_PREFIX=<coarray-icar-install-path>
  make -j <number-of-processes>
  ctest

where

• <path-to-coarray-icar> is the location of of the downloaded coarray ICAR source archive
• <number-of-processes> is a count of the parallel processes that make should use, and
• <compiler-command> is the command you use to invoke the compiler of your choice.
• <coarray-icar-install-path> is the desired location for installing coarray ICAR

For example, you might specify, ~/coarray_icar, 4, caf, and ~/bin, respectively, if the Coarray ICAR source is in your home directoy, you want to accelerate the build by using 4 parallel processes, and you use the command caf to invoke the GNU Fortran compiler via the [OpenCoarrays] wrapper. Alternatively, specify ifort as the compiler command for to invoke the Intel Fortran compiler and optionally specific -DDISTRIBUTED:BOOL=ON to compile using the Intel Parallel Studio Cluster Edition for execution on distributed-memory platforms:

  FC=ifort cmake .. -DDISTRIBUTED:BOOL=ON

Append -DNO_ASSERTIONS=ON to the above cmake command to turn off runtime checking of assertions. Including assertions enhances the runtime error checking at a significant cost (factor of 2 in runtime).

The following operating systems are supported:

• Windows 10 Ubuntu Subsystem for Linux beta
• Linux
• macOS

The following compilers are supported:

• Intel Fortran Compiler Version 16.0.0 or later
• GNU Fortran Compiler Version 6.3.0 (a regression prevents the use of later versions)
• Cray Fortran Compiler (untested)

The following build software is supported:

• CMake 3.10 or later OR
• GNU Makefile

Install the FORD Fortran documentation generator and type

  ford doc-generator.md

which will create doc/ subdirectory containing HTML files. Open doc/index.html for the Coarray ICAR documentation. On Linux, you might exeute the following at the command prompt:

  firefox doc/index.html &