##### Gate 2009 pipelining

Consider a 4 stage pipeline processor. The number of cycles needed by the four instructions I1, I2, I3, I4 in stages S1, S2, S3, S4 is shown below:

S1 S2 S3 S4

I1 2 1 1 1

I2 1 3 2 2

I3 2 1 1 3

I4 1 2 2 2

What is the number of cycles needed to execute the following loop?

For (i=1 to 2) {I1; I2; I3; I4;}

A.16

B.23

C.28

D.30

23