Question

Problem 1:
a) Write LEGv8 assembly language programs for the following C program
  fragments. Please make sure to add any necessary comments.

    P[20] = P[10] + P[30] + 25;

b) Show the machine code that will be generated by the assembly code in
   Problem 1.a. You can write machine code as decimal numbers.

please help me solve this

Answer 1

Let the reference of p be X22

LDUR X9,[X22,#80] //index 8 required offset of 80, temporary register X9 gets p[10]

LDUR X10,[X22,#240] //index 30 required offset of 240, temporary reg X10 gets p[30]

ADD X9,X10,X9 //X10+X9 stored in X9, X9 gets p[10]+p[30]

ADD X9,#25 //X9 gets p[10]+p[30]+25

STUR X9,[X22.#160] //stores p[10]+p[30]+25 in p[20] as index 20 requires offset of 160

Machine code

for ADD opcode is 10001011000, opcode size is 11 and instruction is R format

for LDUR opcode is 11111000010, opcode size is 11 and instruction is D format