+#else
+/* PGI barfs if R is long. Play it safe. */
+# define verify(R) _GL_VERIFY (R, "verify (...)")
+#endif
+
+#ifndef __has_builtin
+# define __has_builtin(x) 0
+#endif
+
+/* Assume that R always holds. This lets the compiler optimize
+ accordingly. R should not have side-effects; it may or may not be
+ evaluated. Behavior is undefined if R is false. */
+
+#if (__has_builtin (__builtin_unreachable) \
+ || 4 < __GNUC__ + (5 <= __GNUC_MINOR__))
+# define assume(R) ((R) ? (void) 0 : __builtin_unreachable ())
+#elif 1200 <= _MSC_VER
+# define assume(R) __assume (R)
+#elif ((defined GCC_LINT || defined lint) \
+ && (__has_builtin (__builtin_trap) \
+ || 3 < __GNUC__ + (3 < __GNUC_MINOR__ + (4 <= __GNUC_PATCHLEVEL__))))
+ /* Doing it this way helps various packages when configured with
+ --enable-gcc-warnings, which compiles with -Dlint. It's nicer
+ when 'assume' silences warnings even with older GCCs. */
+# define assume(R) ((R) ? (void) 0 : __builtin_trap ())
+#else
+ /* Some tools grok NOTREACHED, e.g., Oracle Studio 12.6. */
+# define assume(R) ((R) ? (void) 0 : /*NOTREACHED*/ (void) 0)
+#endif