+#ifdef BUILDING_LIBGUILE
+
+enum scm_opcode
+ {
+#define ENUM(opcode, tag, name, meta) scm_op_##tag = opcode,
+ FOR_EACH_VM_OPERATION(ENUM)
+#undef ENUM
+ };
+
+#define SCM_PACK_OP_24(op,arg) (scm_op_##op | (arg) << 8)
+#define SCM_PACK_OP_8_8_8(op,a,b,c) SCM_PACK_OP_24 (op, (a) | ((b) << 8) | ((c) << 16))
+#define SCM_PACK_OP_8_16(op,a,b) SCM_PACK_OP_24 (op, (a) | (b) << 8)
+#define SCM_PACK_OP_16_8(op,a,b) SCM_PACK_OP_24 (op, (a) | (b) << 16)
+#define SCM_PACK_OP_12_12(op,a,b) SCM_PACK_OP_24 (op, (a) | (b) << 12)
+#define SCM_PACK_OP_ARG_8_24(a,b) ((a) | ((b) << 8))
+
+#define SCM_VM_NUM_INSTRUCTIONS (1<<8)