+/** Returns 0 if tv is positive, else > 0.
+ *
+ * @todo
+ * not tested!
+ */
+int tarval_is_negative(tarval *a);
+
+/** The 'bad' tarval. */
+extern tarval *tarval_bad;
+/** Returns the 'bad tarval. */
+tarval *get_tarval_bad(void);
+
+/** The 'undefined' tarval. */
+extern tarval *tarval_undefined;
+/** Returns the 'undefined' tarval. */
+tarval *get_tarval_undefined(void);
+
+/** The mode_b tarval 'false'. */
+extern tarval *tarval_b_false;
+/** Returns the mode_b tarval 'false'. */
+tarval *get_tarval_b_false(void);
+
+/** The mode_b tarval 'true'. */
+extern tarval *tarval_b_true;
+/** Returns the mode_b tarval 'true'. */
+tarval *get_tarval_b_true(void);
+
+/** The 'void' pointer tarval. */
+extern tarval *tarval_P_void;
+/** Returns the 'void' pointer tarval. */
+tarval *get_tarval_P_void(void);
+
+/* These functions calculate and return a tarval representing the requested
+ * value.
+ * The functions get_mode_{Max,Min,...} return tarvals retrieved from these
+ * functions, but these are stored on initialization of the irmode module and
+ * therefore the irmode functions should be prefered to the functions below. */
+
+/** Returns the maximum value of a given mode. */
+tarval *get_tarval_max(ir_mode *mode);
+
+/** Returns the minimum value of a given mode. */
+tarval *get_tarval_min(ir_mode *mode);
+
+/** Returns the 0 value (additive neutral) of a given mode. */
+tarval *get_tarval_null(ir_mode *mode);
+
+/** Returns the 1 value (multiplicative neutral) of a given mode. */
+tarval *get_tarval_one(ir_mode *mode);
+
+/** Return quite nan for float_number modes. */
+tarval *get_tarval_nan(ir_mode *mode);
+
+/** Return +inf for float_number modes. */
+tarval *get_tarval_inf(ir_mode *mode);
+
+/* ******************** Arithmethic operations on tarvals ******************** */
+
+/**
+ * Compares two tarvals
+ *
+ * Compare a with b and return a pnc_number describing the relation
+ * between a and b. This is either Uo, Lt, Eq, Gt, or False if a or b
+ * are symbolic pointers which can not be compared at all.
+ *
+ * @param a A tarval to be compared
+ * @param b A tarval to be compared
+ *
+ * @return
+ * The pnc_number best describing the relation between a and b is returned.
+ * This means the mode with the least bits set is returned, e.g. if the
+ * tarvals are equal the pnc_number 'Eq' is returned, not 'Ge' which
+ * indicates 'greater or equal'
+ *
+ * @sa
+ * irnode.h for the definition of pnc_numbers
+ */
+pnc_number tarval_cmp(tarval *a, tarval *b);
+
+/**
+ * Converts a tarval to another mode.
+ *
+ * Convert tarval 'src' to mode 'mode', this will suceed if and only if mode
+ * 'mode' is wider than the mode of src, as defined in the firm documentation
+ * and as returned by the function mode_is_smaller defined in irmode.h.
+ *
+ * @param src The tarval to convert
+ * @param mode Tho mode to convert to
+ *
+ * @return
+ * If a tarval of mode 'mode' with the result of the conversion of the 'src'
+ * tarvals value already exists, it will be returned, else a new tarval is
+ * constructed and returned
+ *
+ * @note
+ * Illegal conversations will trigger an assertion
+ *
+ * @sa
+ * FIRM documentation for conversion rules
+ * mode_is_smaller defined in irmode.h
+ */
+tarval *tarval_convert_to(tarval *src, ir_mode *m);
+
+/*
+ * These function implement basic computations representable as opcodes
+ * in FIRM nodes.
+ *
+ * PARAMETERS
+ * tarval_neg:
+ * traval_abs:
+ * a - the tarval to operate on
+ *
+ * all oters:
+ * a - the first operand tarval
+ * b - the second operand tarval
+ *
+ * RESULT
+ * If neccessary a new tarval is constructed for the resulting value,
+ * or the one already carrying the computation result is retrieved and
+ * returned as result.
+ *
+ * NOTES
+ * The order the arguments are given in is important, imagine postfix
+ * notation.
+ * Illegal operations will trigger an assertion.
+ * The sort member of the struct mode defines which operations are valid
+ */
+
+/** Negation of a tarval. */
+tarval *tarval_neg(tarval *a);
+
+/** Addition of two tarvals. */
+tarval *tarval_add(tarval *a, tarval *b);
+
+/** Subtraction from a tarval. */
+tarval *tarval_sub(tarval *a, tarval *b);
+
+/** Multiplication of tarvals. */
+tarval *tarval_mul(tarval *a, tarval *b);
+
+/** 'Exact' division. */
+tarval *tarval_quo(tarval *a, tarval *b);
+
+/** Integer division. */
+tarval *tarval_div(tarval *a, tarval *b);
+
+/** Remainder of integer division. */
+tarval *tarval_mod(tarval *a, tarval *b);
+
+/** Absolute value. */
+tarval *tarval_abs(tarval *a);
+
+/** Bitwise and. */
+tarval *tarval_and(tarval *a, tarval *b);
+
+/** Bitwise or. */
+tarval *tarval_or (tarval *a, tarval *b);
+
+/** Bitwise exclusive or. */
+tarval *tarval_eor(tarval *a, tarval *b);
+
+/** Left shift. */
+tarval *tarval_shl(tarval *a, tarval *b);
+
+/** Unsigned (logical) right shift. */
+tarval *tarval_shr(tarval *a, tarval *b);
+
+/** Signed (arithmetic) right shift. */
+tarval *tarval_shrs(tarval *a, tarval *b);
+
+/** Rotation. */
+tarval *tarval_rot(tarval *a, tarval *b);
+
+/* *********** Output of tarvals *********** */
+
+/**
+ * Returns Bit representation of a tarval value, as string of '0' and '1'
+ *
+ * @param tv The tarval
+ *
+ * This function returns a printable bit representation of any value
+ * stored as tarval. This representation is a null terminated C string.
+ *
+ * @return
+ * As usual in C a pointer to a char is returned. The length of the
+ * returned string if fixed, just read as many chars as the mode defines
+ * as size.
+ *
+ * @note
+ * The string is allocated using malloc() and is free()ed on the next call
+ * of this function.
+ * The string consists of the ascii characters '0' and '1' and is
+ * null terminated
+ *
+ * @sa
+ * irmode.h for the definition of the ir_mode struct
+ * the size member of aforementioned struct
+ */
+char *tarval_bitpattern(tarval *tv);
+
+/**
+ * Returns bitpattern [from, to[.
+ */
+char *tarval_sub_bitpattern(tarval *tv, int from, int to);
+
+/**
+ * Identifying some tarvals ???
+ *
+ * @return
+ * - 0 for additive neutral,
+ * - +1 for multiplicative neutral,
+ * - -1 for bitwise-and neutral
+ * - 2 else
+ *
+ * @deprecated
+ * This function is deprecated and its use strongly discouraged.
+ * Implemented for completeness.
+ */
+long tarval_classify(tarval *tv);
+
+/**
+ * Initialization of the tarval module.
+ *
+ * Call before init_mode().
+ */
+void init_tarval_1(void);
+
+/**
+ * Initialization of the tarval module.
+ *
+ * Call after init_mode().
+ */
+void init_tarval_2(void);
+
+#endif /* _TV_H_ */