In Section 3.6.6, we examined the following code as a candidate for the use of conditional data transfer: long cread (long *xp) {return (xp ? *xp: 0);} We showed a trial implementation using a conditional move instruction but argued that it was not valid, since it could attempt to read from a null address. Write a C function cread_alt that has the same behavior as cread, except that it can be compiled to use conditional data transfer. When compiled, the generated code should use a conditional move instruction rather than one of the jump instructions