I n Praise of Computer Organization and Design: The Hardware/ Software Interface, Fifth Edition “ Textbook selection is of en a frustrating act of compromise—pedagogy, content coverage, quality of exposition, level of rigor, cost. C omputer Organization and Design is the rare book that hits all the right notes across the board, without compromise. It is not only the premier computer organization textbook, it is a shining example of what all computer science textbooks could and should be.” — Michael Goldweber, X avier University “ I have been using C omputer Organization and Design for years, from the very f rst edition. T e new Fif h Edition is yet another outstanding improvement on an already classic text. T e evolution from desktop computing to mobile computing to Big Data brings new coverage of embedded processors such as the ARM, new material on how sof ware and hardware interact to increase performance, and cloud computing. All this without sacrif cing the fundamentals.” — Ed Harcourt, St. Lawrence University “To Millennials: Computer Organization and Design is the computer architecture book you should keep on your (virtual) bookshelf. T e book is both old and new, because it develops venerable principles—Moore's Law, abstraction, common case fast, redundancy, memory hierarchies, parallelism, and pipelining—but illustrates them with contemporary designs, e.g., ARM Cortex A8 and Intel Core i7.” — Mark D. Hill, University of Wisconsin-Madison “ T e new edition of Computer Organization and Design keeps pace with advances in emerging embedded and many-core (GPU) systems, where tablets and smartphones will are quickly becoming our new desktops. T is text acknowledges these changes, but continues to provide a rich foundation of the fundamentals in computer organization and design which will be needed for the designers of hardware and sof ware that power this new class of devices and systems.” — Dave Kaeli, N ortheastern University “ T e Fif h Edition of Computer Organization and Design provides more than an introduction to computer architecture. It prepares the reader for the changes necessary to meet the ever-increasing performance needs of mobile systems and big data processing at a time that dif culties in semiconductor scaling are making all systems power constrained. In this new era for computing, hardware and sof ware must be co- designed and system-level architecture is as critical as component-level optimizations.” — Christos Kozyrakis, S tanford University “ Patterson and Hennessy brilliantly address the issues in ever-changing computer hardware architectures, emphasizing on interactions among hardware and sof ware components at various abstraction levels. By interspersing I/O and parallelism concepts with a variety of mechanisms in hardware and sof ware throughout the book, the new edition achieves an excellent holistic presentation of computer architecture for the PostPC era. T is book is an essential guide to hardware and sof ware professionals facing energy ef ciency and parallelization challenges in Tablet PC to cloud computing.” — Jae C. Oh, S yracuse University This page intentionally left blank F I F T H E D I T I O N C omputer Organization and Design T H E H A R D W A R E / S O F T W A R E I N T E R F A C E D avid A. Patterson has been teaching computer architecture at the University of California, Berkeley, since joining the faculty in 1977, where he holds the Pardee Chair of Computer Science. His teaching has been honored by the Distinguished Teaching Award from the University of California, the Karlstrom Award from ACM, and the Mulligan Education Medal and Undergraduate Teaching Award from IEEE. Patterson received the IEEE Technical Achievement Award and the ACM Eckert-Mauchly Award for contributions to RISC, and he shared the IEEE Johnson Information Storage Award for contributions to RAID. He also shared the IEEE John von Neumann Medal and the C & C Prize with John Hennessy. Like his co-author, Patterson is a Fellow of the American Academy of Arts and Sciences, the Computer History Museum, ACM, and IEEE, and he was elected to the National Academy of Engineering, the National Academy of Sciences, and the Silicon Valley Engineering Hall of Fame. He served on the Information Technology Advisory Committee to the U.S. President, as chair of the CS division in the Berkeley EECS department, as chair of the Computing Research Association, and as President of ACM. T is record led to Distinguished Service Awards from ACM and CRA. At Berkeley, Patterson led the design and implementation of RISC I, likely the f rst VLSI reduced instruction set computer, and the foundation of the commercial SPARC architecture. He was a leader of the Redundant Arrays of Inexpensive Disks (RAID) project, which led to dependable storage systems from many companies. He was also involved in the Network of Workstations (NOW) project, which led to cluster technology used by Internet companies and later to cloud computing. T ese projects earned three dissertation awards from ACM. His current research projects are Algorithm-Machine-People and Algorithms and Specializers for Provably Optimal Implementations with Resilience and Ef ciency. T e AMP Lab is developing scalable machine learning algorithms, warehouse-scale-computer-friendly programming models, and crowd-sourcing tools to gain valuable insights quickly from big data in the cloud. T e ASPIRE Lab uses deep hardware and sof ware co-tuning to achieve the highest possible performance and energy ef ciency for mobile and rack computing systems. J ohn L. Hennessy is the tenth president of Stanford University, where he has been a member of the faculty since 1977 in the departments of electrical engineering and computer science. Hennessy is a Fellow of the IEEE and ACM; a member of the National Academy of Engineering, the National Academy of Science, and the American Philosophical Society; and a Fellow of the American Academy of Arts and Sciences. Among his many awards are the 2001 Eckert-Mauchly Award for his contributions to RISC technology, the 2001 Seymour Cray Computer Engineering Award, and the 2000 John von Neumann Award, which he shared with David Patterson. He has also received seven honorary doctorates. I n 1981, he started the MIPS project at Stanford with a handful of graduate students. Af er completing the project in 1984, he took a leave from the university to cofound MIPS Computer Systems (now MIPS Technologies), which developed one of the f rst commercial RISC microprocessors. As of 2006, over 2 billion MIPS microprocessors have been shipped in devices ranging from video games and palmtop computers to laser printers and network switches. Hennessy subsequently led the DASH (Director Architecture for Shared Memory) project, which prototyped the f rst scalable cache coherent multiprocessor; many of the key ideas have been adopted in modern multiprocessors. In addition to his technical activities and university responsibilities, he has continued to work with numerous start-ups both as an early-stage advisor and an investor. F I F T H E D I T I O N C omputer Organization and Design T H E H A R D W A R E / S O F T W A R E I N T E R F A C E D avid A. Patterson U niversity of California, Berkeley J ohn L. Hennessy S tanford University W ith contributions by David Kaeli Kevin Lim Perry Alexander Northeastern University Hewlett-Packard T e University of Kansas Nicole Kaiyan John Nickolls Peter J. Ashenden University of Adelaide NVIDIA Ashenden Designs Pty Ltd David Kirk John Oliver Jason D. Bakos NVIDIA Cal Poly, San Luis Obispo University of South Carolina James R. Larus Milos Prvulovic Javier Bruguera School of Computer and Georgia Tech Communications Science at EPFL Universidade de Santiago de Compostela Partha Ranganathan Jacob Leverich Jichuan Chang Hewlett-Packard Hewlett-Packard Hewlett-Packard Matthew Farrens University of California, Davis A MSTERDAM • BOSTON • HEIDELBERG • LONDON NEW YORK • OXFORD • PARIS • SAN DIEGO SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO M organ Kaufmann is an imprint of Elsevier A cquiring Editor: Todd Green D evelopment Editor: Nate McFadden P roject Manager: Lisa Jones D esigner: Russell Purdy M organ Kaufmann is an imprint of Elsevier T e Boulevard, Langford Lane, Kidlington, Oxford, OX5 1GB 2 25 Wyman Street, Waltham, MA 02451, USA C opyright © 2014 Elsevier Inc. All rights reserved N o part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: w ww.elsevier.com/permissions T is book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein). N otices K nowledge and best practice in this f eld are constantly changing. As new research and experience broaden our understanding, changes in research methods or professional practices, may become necessary. Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information or methods described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility. T o the fullest extent of the law, neither the publisher nor the authors, contributors, or editors, assume any liability for any injury and/ or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein. L ibrary of Congress Cataloging-in-Publication Data P atterson, David A. C omputer organization and design: the hardware/sof ware interface/David A. Patterson, John L. Hennessy. — 5th ed. p . cm. — (T e Morgan Kaufmann series in computer architecture and design) R ev. ed. of: Computer organization and design/John L. Hennessy, David A. Patterson. 1998. S ummary: “Presents the fundamentals of hardware technologies, assembly language, computer arithmetic, pipelining, memory hierarchies and I/O”— Provided by publisher. I SBN 978-0-12-407726-3 (pbk.) 1 . Computer organization. 2. Computer engineering. 3. Computer interfaces. I. Hennessy, John L. II. Hennessy, John L. Computer organization and design. III. Title. B ritish Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library I SBN: 978-0-12-407726-3 F or information on all MK publications visit our website at w ww.mkp.com P rinted and bound in the United States of America 1 3 1 4 1 5 1 6 1 0 9 8 7 6 5 4 3 2 1 T o Linda, who has been, is, and always will be the love of my life A C K N O W L E D G M E N T S F igure 1.10.4 Courtesy of Cray Inc. F igures 1.7, 1.8 Courtesy of iFixit (w ww.if xit.com) . F igure 1.10.5 Courtesy of Apple Computer, Inc. F igure 1.9 Courtesy of Chipworks ( www.chipworks.com) . F igure 1.10.6 Courtesy of the Computer History Museum. F igure 1.13 Courtesy of Intel. F igures 5.17.1, 5.17.2 Courtesy of Museum of Science, Boston. Figures 1.10.1, 1.10.2, 4.15.2 Courtesy of the Charles Babbage Institute, University of Minnesota Libraries, Minneapolis. F igure 5.17.4 Courtesy of MIPS Technologies, Inc. F igures 1.10.3, 4.15.1, 4.15.3, 5.12.3, 6.14.2 Courtesy of IBM. F igure 6.15.1 Courtesy of NASA Ames Research Center. Contents Preface xv C H A P T E R S 1 Computer Abstractions and Technology 2 1.1 Introduction 3 1.2 Eight Great Ideas in Computer Architecture 11 1.3 Below Your Program 13 1.4 Under the Covers 16 1.5 Technologies for Building Processors and Memory 24 1.6 Performance 28 1.7 T e Power Wall 40 1.8 T e Sea Change: T e Switch from Uniprocessors to Multiprocessors 43 1.9 Real Stuf : Benchmarking the Intel Core i7 46 1.10 Fallacies and Pitfalls 49 1.11 Concluding Remarks 52 1.12 Historical Perspective and Further Reading 54 1.13 Exercises 54 2 Instructions: Language of the Computer 60 2.1 Introduction 62 2.2 Operations of the Computer Hardware 63 2.3 Operands of the Computer Hardware 66 2.4 Signed and Unsigned Numbers 73 2.5 Representing Instructions in the Computer 80 2.6 Logical Operations 87 2.7 Instructions for Making Decisions 90 2.8 Supporting Procedures in Computer Hardware 96 2.9 Communicating with People 106 2.10 MIPS Addressing for 32-Bit Immediates and Addresses 111 2.11 Parallelism and Instructions: Synchronization 121 2.12 Translating and Starting a Program 123 2.13 A C Sort Example to Put It All Together 132 2.14 Arrays versus Pointers 141