— Function: int mpq_cmp (const mpq_t op1, const mpq_t op2)

Compare op1 and op2. Return a positive value if op1 > op2, zero if op1 = op2, and a negative value if op1 < op2.

To determine if two rationals are equal, mpq_equal is faster than mpq_cmp.

— Macro: int mpq_cmp_ui (const mpq_t op1, unsigned long int num2, unsigned long int den2)
— Macro: int mpq_cmp_si (const mpq_t op1, long int num2, unsigned long int den2)

Compare op1 and num2/den2. Return a positive value if op1 > num2/den2, zero if op1 = num2/den2, and a negative value if op1 < num2/den2.

num2 and den2 are allowed to have common factors.

These functions are implemented as a macros and evaluate their arguments multiple times.

— Macro: int mpq_sgn (const mpq_t op)

Return +1 if op > 0, 0 if op = 0, and -1 if op < 0.

This function is actually implemented as a macro. It evaluates its argument multiple times.

— Function: int mpq_equal (const mpq_t op1, const mpq_t op2)

Return non-zero if op1 and op2 are equal, zero if they are non-equal. Although mpq_cmp can be used for the same purpose, this function is much faster.