+/**
+ * Create a new opcode.
+ * @param opc The Firm opcode.
+ * @param name A name.
+ * @param commutative True, if the opcode is commuatative.
+ */
+void rflct_new_opcode(opcode opc, const char *name, bool commutative);
+
+/**
+ * Add a signature to the opcode.
+ * @param opc The opcode.
+ * @param args The signature.
+ * @return true, if the signature was added sucessfully, false if no
+ * more signatures can be added to the opcode.
+ */
+bool rflct_opcode_add_signature(opcode opc, rflct_sig_t *sig);
+
+/**
+ * Allocate a new signature.
+ * @param defs Number of def arguments.
+ * @param uses Number of use arguments.
+ * @return An allocated signature.
+ */
+rflct_sig_t *rflct_signature_allocate(int defs, int uses);
+
+/**
+ * Set an argument in a signature.
+ * @param sig The signature.
+ * @param is_use true, if the argument is a use, else it is considered a
+ * def.
+ * @param num The index of the argument.
+ * @param name The name of the argument.
+ * @param mc The mode class of the argument.
+ * @param is_variadic true, if the argument is variadic.
+ * @param mode_equals This variable has following meaning. If the
+ * argument is variadic, a 1 indicates that all operands binding to this
+ * argument must have the same mode. A 0 indicates, that their mode must
+ * be of the specified mode class but can differ. If the argument is non
+ * variadic, a positive number indicates, that the mode of the operand
+ * binding to this argument must be the same as the one binding to
+ * argument indexed by mode_equals. If the mode should not be dependent
+ * to another mode, set -1 here.
+ * @return The index of the argument. Only use this index in mode_equals
+ * parameters of other arguments.
+ */
+int rflct_signature_set_arg(rflct_sig_t *sig, bool is_use, int num,
+ const char *name, rflct_mode_class_t mc, bool is_variadic, int mode_equals);
+
+/**
+ * Get the arguments array index for an argument.
+ * @param sig The signature.
+ * @param is_use True, if the argument indicates a use or def argument.
+ * @param num The number of the argument.
+ * @return The index into the arguments array.
+ */
+int rflct_signature_get_index(const rflct_sig_t *sig, bool is_use, int num);
+
+