Hi! The test FAILs on 32-bit targets that don't have __int128 type.
Fixed thusly, regtested on x86_64-linux and i686-linux, committed to trunk as obvious. 2020-03-12 Jakub Jelinek <ja...@redhat.com> PR c++/93907 * g++.dg/cpp2a/concepts-using2.C (cc): Use long long instead of __int128 if __SIZEOF_INT128__ isn't defined. --- gcc/testsuite/g++.dg/cpp2a/concepts-using2.C.jj 2020-03-11 23:31:45.818595378 +0100 +++ gcc/testsuite/g++.dg/cpp2a/concepts-using2.C 2020-03-12 01:25:44.011097711 +0100 @@ -15,7 +15,11 @@ template <typename b> using an = typenam template <typename> constexpr bool ao = c<true>::d; template <typename> constexpr bool i = c<1>::d; template <typename> concept bb = i<b>; +#ifdef __SIZEOF_INT128__ using cc = __int128; +#else +using cc = long long; +#endif template <typename> concept cd = bb<cc>; template <typename bt> concept ce = requires { requires cd<bt>; }; template <typename bt> concept h = ce<bt>; Jakub