1. Write a LEGv8 assembly code to compute the sum and mean of four 64-bit values. The four values are stored in an array. Compute the sum and mean and store the sum and mean in X20 and X21 respectively. Assume all values are 64-bits. Do not use divide and branch instructions in your code. Comment your assembly code. (You can use the some code from the test. S in Programming Assignment 0, there was an array with 3 values; but you need an array with 4 values here)