https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67068
--- Comment #2 from Mike Glass <mwglass at sandia dot gov> --- Yes, all the FORTRAN code is compiled with those options. We want to mimic the behavior of the Intel compiler when we add the '-r8' flag to their compiler: Makes default real and complex declarations, constants, functions, and intrinsics 8 bytes long. REAL declarations are treated as DOUBLE PRECISION (REAL(KIND=8)) and COMPLEX declarations are treated as DOUBLE COMPLEX (COMPLEX(KIND=8)). Real and complex constants of unspecified KIND are evaluated in double precision (KIND=8).