1. Write the following C code in MIPS assembler: x = x + y + z - q; Assume that x, y, z, q are stored in registers $s1-$s4. 2. Describe the difference between carry and overflow. For each of the following, state if it is a carry, an overflow, or neither. (a) 1011 + 0111 (unsigned) (b) 0111 + 0010 (unsigned) (c) 0111 + 0010 (signed) (d) 1000 + 0111 (signed) 3. Convert the C function below to a MIPS assembly language subroutine. Then write code that calls the subroutine (assuming that n is in $a0) and stores the return value in $v0. unsigned int func(unsigned int n) { if (n == 0) return 0; else return n - 1; } 4. Use the register values below for the next questions. Assume each of the following questions starts from the original values; that is, DO NOT use value changes from one question as propagating into future parts of the question. $s0=5 $s1=6 $s2=7 (a) Give the values of $s0, $s1 and $s2 after this instruction: add $s0, $s1, $s2 (b) Give the values of $s0, $s1 and $s2 after this instruction: sub $s0, $s2, $s1 (c) Give the value of $s0 after this instruction: addi $s0, $s0, -1 5. Write instructions to push $s0 to the stack and instructions to pop it off. PUSH: POP: 6. Convert -67 and 42 into binary, using twos decimal representation for the negative number. Add the numbers. Convert the result back to decimal. Show all your work. 7. Fill in the immediate field in the ORI instruction below to force bits 5 and 7 of $t0 to be 1, while leaving all other bits unchanged. ORI $t0, $t0, 0x_________________ 8. What does the following code do? Rewrite the code using sll instead of add. add $t0, $t0, $t0 9. Write MIPS code to implement the following loop: for (i=0; i<3;i++) array[i] += 3; // assume address of array is in $s6, and $s3 = i which is initialized to zero 10. For each addressing mode, write a sample instruction using that mode. 11. (a) What is this MIPS statement: 0x012b8022 (b) Convert the following MIPS statement to machine/hex code: or $s0, $t2, $t5 Chapter 3 Questions 12. Write an add instruction to add the value in $t0 to $t1 and store it in $s0. Use an instruction that will not cause an overflow. 13. (a) Convert 35 to binary (b) convert -9 to binary (c) add the two numbers in binary. Assume all operands are 8 bits. 14. Write instruction(s) to multiply the value in $t0 by the value in $t1. Both may be 32 bits. 15. What is the difference between add and addu? 16. Describe how the hi/lo registers are used in multiplication.