http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48404
--- Comment #9 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-04-06 06:53:53 UTC --- (In reply to comment #8) > My gcc4.5 and gcc4.4 apparently did not have libquadmath-support Yes, libquadmath is a new GCC 4.6 feature, cf. http://gcc.gnu.org/gcc-4.6/changes.html and http://gcc.gnu.org/onlinedocs/libquadmath/ -- While primarily added and used for gfortran, it also can be used with C/C++. On GLIBC systems, libquadmath has printf hooks, allowing one to use the __float128 directly in (s,sn,f,)printf. (On other systems, quadmath_snprintf has to be used.) > Not much can be done if the packages get it wrong. Thanks for the help. I'll > close the bug report. Thanks. (In terms of compatibility of older programs with newer "libgfortan"s, it is unfortunate. However, as the capabilities of the compiler are checked during the compilation of the library, it is difficult to avoid. Fortunately, it only affects SELECTED_REAL_KIND where the arguments are not known at compile time. -- The Fortran 2008 "workaround" is to use ISO_Fortran_env's REAL_KINDS, which gfortran supports since GCC 4.6 - but F2008 only and GCC since 4.6 does not make it really portable.)