Q$2(40\%)$

In this exercise, we examine how data dependences affect 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 $r1,r2,r3$

or $r{r}_{,}r1,r{4}_{?}$

or $r1,r1,r{2}_{?}$

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

Indicate dependences and their type.

Assume there is no forwarding in this pipelined processor. Indicate hazards and add

nop instructions to eliminate them. X cycles multiply by $250$

Assume there is full forwarding. Indicate hazards and add NOP instructions to

eliminate them. Y cycles multiply by $300$

What is the total execution time of this instruction sequence without forwarding and

with full forwarding? What is the speedup achieved by adding full forwarding to a

pipeline that had no forwarding?