https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85672
--- Comment #1 from Marc Glisse <glisse at gcc dot gnu.org> --- I think there is an inconsistency where we #define _GLIBCXX_USE_FLOAT128 0 (can you check your c++config.h?) to say that it shouldn't be supported, but then test with #ifdef and not #if.
