https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85672
--- Comment #1 from Marc Glisse ---
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.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85672
--- Comment #2 from John David Anglin ---
The config file looks like this:
/* Define if __float128 is supported on this host. */
# define _GLIBCXX_USE_FLOAT128 0
#if !defined(__FLOAT128__) && !defined(__SIZEOF_FLOAT128__)
#undef _GLIBCXX_USE_FLO
