-#define SCM_GSUBR_MAKTYPE(req, opt, rst) ((req)|((opt)<<4)|((rst)<<8))
-#define SCM_GSUBR_MAX 33
-#define SCM_GSUBR_REQ(x) ((long)(x)&0xf)
-#define SCM_GSUBR_OPT(x) (((long)(x)&0xf0)>>4)
-#define SCM_GSUBR_REST(x) ((long)(x)>>8)
+/* Subrs
+ */
+
+/* Max number of args to the C procedure backing a gsubr */
+#define SCM_GSUBR_MAX 10
+
+#define SCM_PRIMITIVE_P(x) (SCM_PROGRAM_P (x) && SCM_PROGRAM_IS_PRIMITIVE (x))
+
+#define SCM_PRIMITIVE_GENERIC_P(x) (SCM_PROGRAM_P (x) && SCM_PROGRAM_IS_PRIMITIVE_GENERIC (x))
+
+#define SCM_SUBRF(x) \
+ ((SCM (*) (void)) \
+ SCM_POINTER_VALUE (SCM_PROGRAM_FREE_VARIABLE_REF (x, 0)))
+
+#define SCM_SUBR_NAME(x) (SCM_PROGRAM_FREE_VARIABLE_REF (x, 1))
+
+#define SCM_SUBR_GENERIC(x) \
+ ((SCM *) SCM_POINTER_VALUE (SCM_PROGRAM_FREE_VARIABLE_REF (x, 2)))
+
+#define SCM_SET_SUBR_GENERIC(x, g) \
+ (*SCM_SUBR_GENERIC (x) = (g))
+
+\f
+
+SCM_INTERNAL int scm_i_primitive_arity (SCM subr, int *req, int *opt, int *rest);
+SCM_INTERNAL scm_t_uintptr scm_i_primitive_call_ip (SCM subr);