Coarrays in GNU Fortran

Coarray Fortran is a set of features of the Fortran 2008 standard which makes Fortran a PGAS language. Currently, the coarray support is provided mainly by commercial compilers like Cray and Intel. In this work we present two coarray implementations on the GNU Fortran compiler. We present a performance comparison between our coarray implementations and those provided by Cray and Intel. Such comparison includes synthetic benchmarks and real, commonly used, scientific applications.