CSSE232 : Computer Architecture I

Name: Box: Date:

HW7

In the following assembly code fragment, registers $t1 and $t2 are initialized to N and zero respectively.
```
LOOP: beq  $t1, $0, DONE
      addi $t2, $t2, 1
      addi $t1, $t1, -1
      j LOOP
DONE:
```
a. (2 points) What is the value in register $t2 for when the code reaches the label DONE:?

b. (2 points) How many MIPS instructions are executed?

c. (6 points) If the registers $t1 and $t2 correspond to variables i and a respectively, write the equivalent C code for the loop.

Consider the following C code fragment.
```
for (i=0; i<a; i++) {
  a = a + b;
}
```
a. (4 points) Assuming that the values of i, a, and b in registers $t0, $t1 and $t2, translate the C code to MIPS assembly. Use a minimum number of instructions.

b. (4 points) If the variables a and b are initialized to 10 and 1, what is the total number of MIPS instructions executed?