Assume that the following sequence of instructions is executed on a 5-stage pipelined datapath:

ADD R5,R2,R1

LW R3,4(R5)

LW R2,0(R2)

OR R3,R5,R3

SW R3,0(R5)

a. If there is no forwarding or hazard detection, insert NOPs to ensure correct execution. (10)

b. Now use nops only when a hazard cannot be avoided by changing or rearranging these instructions. You can assume register R7 can be used to hold temporary values in your modified code. (10)