Question

Problem 1: Write a function add64 that adds two input unsigned 64 bit integers x and y and returns the unsigned 64 bit integer sum z, i.e. zx+y. In your main function, you should assume that x, y, and z will be stored in the following 6 registers as follows: x: upper 32 bits in $t1 y: upper 32 bits in St3 z: upper 32 bits in St5 lower 32 bits in $to lower 32 bits in $t2 lower 32 bits in $t4 Your main function call should read the values of x and y into the stack, invoke add64, and then return z on the stack. Also, your function should generate an error only if there is an overflow in the overall 64 bit addition (and not if there is an overflow in the addition of the lower 32 bit components).