https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119244
--- Comment #16 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Note, a check for IEEE quad long double case could be #if __LDBL_MANT_DIG__ == 113 && __LDBL_MIN_EXP__ == -16381 // Use long double, l suffix on calls, l or L suffix in literals #elif __FLT128_MANT_DIG__ == 113 && __FLT128_MIN_EXP__ == -16381 && defined(USE_IEC_60559) // Use _Float128, f128 suffix on calls, f128 or F128 suffix on literals #else // Use __float128, q suffix on calls, q or Q suffix on literals #endif and configure making sure the library isn't configured in if none of those is available.
