Instruction Level parallelism (ILP)

• ILP will increase throughput and decrease CPU execution time

• ILP will increase structural hazards

  • Cannot issue 2 instructions to the same pipe

• ILP makes reduction in other stalls even more important

  • A “bubble” costs more than the loss of a single instruction issue

• ILP will make the design more complex

  • WAW and WAR hazards can occur
  • Out-of-order completion can occur
  • Precise exception handling is more difficult
    

Previous slide

Next slide

Back to first slide

View graphic version