diff --git a/configure.ac b/configure.ac index 75ee1a7c01c..3f747bf38cc 100644 --- a/configure.ac +++ b/configure.ac @@ -445,7 +445,8 @@ int main() { struct { uint64_t *v; } x; - return (int)__atomic_load_n(x.v, __ATOMIC_ACQUIRE); + return (int)__atomic_load_n(x.v, __ATOMIC_ACQUIRE) & + (int)__atomic_add_fetch(x.v, (uint64_t)1, __ATOMIC_ACQ_REL); }]])], GCC_ATOMIC_BUILTINS_SUPPORTED=yes, GCC_ATOMIC_BUILTINS_SUPPORTED=no) dnl If that didn't work, we try linking with -latomic, which is needed on some @@ -459,7 +460,8 @@ if test "x$GCC_ATOMIC_BUILTINS_SUPPORTED" != xyes; then struct { uint64_t *v; } x; - return (int)__atomic_load_n(x.v, __ATOMIC_ACQUIRE); + return (int)__atomic_load_n(x.v, __ATOMIC_ACQUIRE) & + (int)__atomic_add_fetch(x.v, (uint64_t)1, __ATOMIC_ACQ_REL); }]])], GCC_ATOMIC_BUILTINS_SUPPORTED=yes LIBATOMIC_LIBS="-latomic", GCC_ATOMIC_BUILTINS_SUPPORTED=no) LDFLAGS=$save_LDFLAGS