https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85440
--- Comment #15 from Jakub Jelinek <jakub at gcc dot gnu.org> --- For libquadmath you need a working __float128 support. On x86_64, i686 and ia64 this is done through a slow software emulation in libgcc. On powerpc*, there is either a software emulation which requires VSX, or hardware implementation which requires power9. On s390 there is hardware implementation, but long double is already quad, so you don't need libquadmath. For everything else, just use mpfr.
