Consider the Following Assembly Language Code

question 20

Essay

Consider the following assembly language code:
I0: ADD R4 = R1 + R0; I1: SUB R9 = R3 - R4; I2: ADD R4 = R5 + R6;
I3: LDW R2 = MEM[R3 + 100]; I4: LDW R2 = MEM[R2 + 0]; I5: STW MEM[R4 + 100] = R2; I6: AND R2 = R2 & R1;
I7: BEQ R9 == R1, Target; I8: AND R9 = R9 & R1;
Consider a pipeline with forwarding, hazard detection, and 1 delay slot for branches. The
pipeline is the typical 5-stage IF, ID, EX, MEM, WB MIPS design. For the above code, complete the pipeline diagram below (instructions on the left, cycles on top) for the code. Insert the characters IF, ID, EX, MEM, WB for each instruction in the boxes. Assume that there two levels of bypassing, that the second half of the decode stage performs a read of source registers, and that the first half of the write-back stage writes to the register file.
Label all data stalls (Draw an X in the box). Label all data forwards that the forwarding unit detects (arrow between the stages handing off the data and the stages receiving the data). What is the final execution time of the code?