I have some legacy Fortran code (Several hundreds of lines long). The code works fine in older versions of GCC (6.3) at the uni, but on newer versions it returns NaN.
What options can I add to modern gfortran (Not installing an old version) for potentially fixing this issue.
What I've tried: -std=legacy and -m32,-mpc32. (Since I'm not sure whether the working compiler is 32 or 64 bits) All return NaN (-m32 is also slow)