Oregon State University, Corvallis

CS 472

Homework 1 Due Oct 14 at 8am Points 20 Questions 16 Available until Dec 20 at 11:59pm Time Limit None Instructions Attempt History Attempt Time Score LATEST Attempt 1 4,682 minutes 8 out of 20 Score for this quiz: 8 out of 20 Submitted Oct 14 at 5:41am This attempt took 4,682 minutes. Homework #1 covers the topics taught in Module 1 and Module 2. It consists of 4 Questions (each of them consists of sub-questions ) There is no time-limit. Question 1 In this question, we will compare the performance of two processors, pA and pB. The processors are identical except: The ALU in pB has specialized multiplier logic and supports the mult instruction The ALU in pA does not have multiplier logic and does not support the mult instruction pB's cycle time is 20% longer than pA's cycle time due to the added complexity Because pA does not support a mult instruction, multiplication must be done by a software algorithm that uses other available instructions to calculate the result. (The assembler for pA provides a mult pseudo-instruction, which is expanded to several instructions during assembly.) Assume the following real-world instruction distribution for each processor running the same workload. pA pB CPI MULT 0% 5% 32 LW 5% 25% 3 SW 5% 25% 2 R-TYPE 70% 15% 1 BEQ 20% 30% 2 12/5/2020 Homework 1: COMPUTER ARCHITECTURE (CS_472_X001_F2020) https://canvas.oregonstate.edu/courses/1781618/quizzes/2593664 2/15 Q 0 / 1 pts uestion 1 Question 1.1 What is the average CPI of pA for this workload? Exact answer. 3 You Answered Correct Answers 1.35 (with margin: 0) 1.35 = 0.05(3) + 0.05(2) + 0.70(1) + 0.20(2) Q 0 / 1 pts uestion 2 Question 1.2 What is the average CPI of pB for this workload? Exact answer.