in file Gmp.php, method Crypt_DiffieHellman_Math_BigInteger_Gmp::compare() Compare two big integers and returns result as an integer where 0 means both are identical, 1 that left_operand is larger, or -1 that right_operand is larger.
compare
in file Bcmath.php, method Crypt_DiffieHellman_Math_BigInteger_Bcmath::compare() Compare two big integers and returns result as an integer where 0 means both are identical, 1 that left_operand is larger, or -1 that right_operand is larger.