In this exercise, we examine how data dependences aff ect execution in the basic $5-$stage pipeline described in

Section $4\mathrm{.}5.$ Problems in this exercise refer to the following sequence of instructions:

or r$1,$r$2,$r$3$

or r$2,$r$1,$r$4$

or r$1,$r$1,$r$2$

Also, assume the following cycle times for each of the options related to forwarding:

Without Forwarding$250$ps

With Full Forwarding$300$ps

a$.$ Indicate dependences and their type.

b$.$ Assume there is no forwarding in this pipelined processor. Indicate hazards and add nop instructions to eliminate them.

c$.$ Assume there is full forwarding. Indicate hazards and add NOP instructions to eliminate them.

d$.$ What is the total execution time of this instruction sequence without forwarding and with full forwarding?

e$.$ What is the speedup achieved by adding full forwarding to a pipeline that had no forwarding?