The program has been compiled in MIPS assembly code assuming that registers $t6 and $t7 have been initialized with values 0 and 4 N respectively. The symbols VECTA and VECTB are 16-bit constant. The processor clock frequency is 1 GHz.

a) Apply loop unrolling (as well as instruction re-ordering, if you like) on the above MIPS code for two iterations. Write the corresponding MIPS instruction code.

b) Draw the pipeline execution diagram of your MIPS instructions (one iteration of the new loop would be enough) and compute the average CPI of the loop.

FOR beq $t6, $t7 , END # if ($t6 =- $t7) goto END add $t2, $t2,$t3 # $t2 $t2