Fortran Compilers described at fortran-lang.org
Polyhedron Software compiler comparisons
HECToR Fortran Compiler Performance Comparison
Summary of Mac Fortran Compiler options
A performance comparison of Mac Fortran compilers
Compiler support for Fortran 2008 and 2018 - PDF file. This is updated regularly and also appears in ACM Fortran Forum.
fortran-compiler-tests collection of Fortran compiler bug examples and tests.