https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104220
--- Comment #1 from Tobias Burnus <burnus at gcc dot gnu.org> --- Testing now: --- a/libgfortran/ieee/issignaling_fallback.h +++ b/libgfortran/ieee/issignaling_fallback.h @@ -140 +140 @@ __issignalingl (long double x) -#elif (__LDBL_DIG__ = 33) && __LDBL_IS_IEC_60559__ +#elif (__LDBL_DIG__ == 33) && __LDBL_IS_IEC_60559__