+ /**
+ * Generate the prologue.
+ * @param self The callback object.
+ * @param mem A pointer to the mem node. Update this if you define new memory.
+ * @param reg_map A mapping mapping all callee_save/ignore/parameter registers to their defining nodes.
+ * @return The register which shall be used as a stack frame base.
+ *
+ * All nodes which define registers in @p reg_map must keep @p reg_map current.
+ */
+ const arch_register_t *(*prologue)(void *self, ir_node **mem, pmap *reg_map);
+
+ /**
+ * Generate the epilogue.
+ * @param self The callback object.
+ * @param mem Memory one can attach to.
+ * @param reg_map A mapping mapping all callee_save/ignore/return registers to their defining nodes.
+ *
+ * All nodes which define registers in @p reg_map must keep @p reg_map current.
+ * Also, the @p mem variable must be updated, if memory producing nodes are inserted.
+ */