+#ifdef powerpc64_HOST_ARCH
+#define JMP_(cont) ((F_) (cont))()
+#endif
+
+/* -----------------------------------------------------------------------------
+ Tail calling on IA64
+ -------------------------------------------------------------------------- */
+
+#ifdef ia64_HOST_ARCH
+
+/* The compiler can more intelligently decide how to do this. We therefore
+ * implement it as a call and optimise to a jump at mangle time. */
+#define JMP_(cont) ((F_) (cont))(); __asm__ volatile ("--- TAILCALL ---");
+
+/* Don't emit calls to __DISCARD__ as this causes hassles */
+#define __DISCARD__()
+
+#endif