Course Overview Computer Systems Programming …...C++ under the hood Movidius Myriad 2 I Custom chip for ML on embedded IoT devices I Carefully crafted C/C++ ML libraries for inference

ECE 2400 / ENGRD 2140Computer Systems Programming

Course Overview

Christopher BattenSchool of Electrical and Computer Engineering

Cornell University

http://www.csl.cornell.edu/courses/ece2400

What is Computer Systems Programming? Activity Trends in Computer Systems Programming Course Logistics

Application-LevelSoftware

System-LevelSoftware


What is Computer Systems Programming?

Activity: Comparing Algorithms

Trends in Computer Systems Programming

Course Logistics

ECE 2400 Course Overview 2 / 30

• What is Computer Systems Programming? • Activity Trends in Computer Systems Programming Course Logistics

The Computer Systems Stack

Application

Gap too large to bridge in one step(but there are exceptions, e.g., a magnetic compass)

Technology



The Computer Systems Stack

In its broadest definition, computer engineering is thedevelopment of the abstraction/implementation layers that allow us to

execute information processing applications efficientlyusing available manufacturing technologies

Register-Transfer Level

Circuits

Devices

Instruction Set Architecture

Programming Language

Algorithm

Microarchitecture

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Application

Operating System

Gate Level

Compiler

Technology

TraditionalComputer Science

TraditionalElectrical Engineering

Computer Engineering is at theinterface between hardware and softwareand considers the entire system



Python for Application-Level Programming


Circuits

Devices



Algorithm

Microarchitecture

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Application

Operating System

Gate Level

Compiler

Technology


?

I High-level, user-facing software

I Enable productivelydevelopingapplications thatprovide newfunctionality tousers

I Enable productivelycollecting,analyzing,visualizing data

I Sometimes called aproductivity-levellanguage



C/C++ for System-Level Programming


Circuits

Devices



Algorithm

Microarchitecture

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Application

Operating System

Gate Level

Compiler

Technology


?System-LevelSoftware

I Connectsapplication softwareto the low-levelcomputer hardware

I Enables carefullymanagingperformance andresource constraints

I Sometimes calledan efficiency-levellanguage



Dynamically Interpreted vs. Statically Compiled

PythonSource Code

"Runtime"Compiler

PythonBytecode

Executew/ Interpreter

PythonLibrary Code

"Runtime"Compiler

PythonBytecode

def min(a,b): if a < b: c = aelse

c = b return c

LOAD_FASTLOAD_FASTCOMPARE_OPPOP_JUMP_IF_FLOAD_FASTSTORE_FASTJUMP_FORWARDLOAD_FASTSTORE_FASTLOAD_FASTRETURN_VALUE

C/C++

Source Code

Ahead-of-TimeCompiler

MachineObject File

Linker

MachineBinary

ExecuteBinary

C/C++Library Code

Ahead-of-TimeCompiler

MachineObject File

pushq %rbpmovq %rsp,%rbpcmpl %esi,%edicmovl %edi,%esimovl %esi,%eaxpopq %rbpretq

int min( int a, int b ){int c; if ( a < b ) c = a; else

c = b; return c;}

101010110010001000100111100111110111111101001110111100010011111000101110111000011

The standard Pythoninterpreter is called CPythonand it is written in C!



Computer Systems Programming is Diverse


Circuits

Devices



Algorithm

Microarchitecture

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Application

Operating System

Gate Level

Compiler

Technology


?System-LevelSoftware

I Python, MATLABI Ruby, JavascriptI SQL, LINQI NumPyI GUI frameworks

I InterpretersI CompilersI DatabasesI Numerical librariesI Operating systemsI Embedded control



Aside: C/C++ for Application-Level Software


Circuits

Devices



Algorithm

Microarchitecture

Co

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Application

Operating System

Gate Level

Compiler

Technology


?

Application-Level&




A Tale of Two Programming Languages

Python Programming Language

I Introduced: 1991

I Most of the machine details arehidden from programmer

I Programmer gives up somecontrol for improved productivity

I Easily supports multipleprogramming paradigms

I Extensive standard library isincluded

I Slow and memory inefficient

C/C++ Programming Language

I Introduced: 1972(C), 1979(C++)

I Most of the machine details areexposed to the programmer

I Programmer is in completecontrol for improved efficiency

I Easily supports multipleprogramming paradigms

I More limited standard library isincluded

I Fast and memory efficient



Comparing the Popularity of Python vs. C/C++

The 2018 Top Programming Languages, IEEE Spectrum



Comparing the Performance of Python vs. C/C++

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The Computer Language Benchmarks Game



Program = Algorithm + Data Structure

While this course covers C/C++ and system-level programming, thiscourse also builds off of your prior programming experience to further

develop your understanding of algorithms and data structures

Data StructureAlgorithm

I Algorithm: Clear set of steps to solve any problem instance in aparticular class of problems

I Data Structure: Way of efficiently organizing and storing dataalong with methods for accessing and manipulating this data


What is Computer Systems Programming? • Activity • Trends in Computer Systems Programming Course Logistics







Course Logistics




I Application: Sort 16 numbers

I Activity Steps. 1. Half the class will use Algorithm A, half uses Algorithm B. 2. When instructor starts timer, flip over worksheet. 3. Sort 16 numbers using assigned algorithm. 4. Lookup when completed and write time on worksheet. 5. Raise hand. 6. When everyone is finished, then analyze data

I Algorithm A

repeat 16 times

find smallest number not crossed off in input list

copy smallest number to next open entry in output list

cross smallest number off input list




I Algorithm B

repeat 8 times, once for each pair in column 1

copy smallest from input pair into next entry in column 1

copy largest from input pair into next entry in column 1

repeat 4 times, once for group of 4 in column 2

repeat 4 times

compare top two numbers not crossed off in both groups

copy smallest number to next open entry in column 2

cross smallest number off input list

... and so on ...


What is Computer Systems Programming? Activity • Trends in Computer Systems Programming • Course Logistics







Course Logistics



Trend towards IoT and Cloud w/ Novel Hardware

Roughly every decade a new, smaller, lower priced computer class formsbased on a new programming platform resulting in entire new industries

103

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1950 1960 1970 1980 2000 2010

G. Bell. "Bell's Law for the Birth and Death of Computer Classes."CACM, Jan 2008.

1990

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m3

2020 1950 1960 1970 1980 2000 20101990 2020

Y. Lee et al. "Modular 1mm3 Die-Stacked Sensing Platform ..."JSSC, Jan 2013.

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Mainframes

Mainframes

Minicomputers

Minicomputers

Workstations

WorkstationsPersonalComputers

PersonalComputers

Laptops

LaptopsHandhelds

Handhelds

Supercomputers

ScalableClusters

CloudComputing

Internetof Things

Internetof Things



Trend towards IoT and Cloud w/ Novel Hardware

Roughly every decade a new, smaller, lower priced computer class formsbased on a new programming platform resulting in entire new industries

103

104

105

106

107

108

102

Pri

ce

in

Do

lla

rs

1950 1960 1970 1980 2000 2010

G. Bell. "Bell's Law for the Birth and Death of Computer Classes."CACM, Jan 2008.

1990

Vo

lum

e i

n c

m3

2020 1950 1960 1970 1980 2000 20101990 2020

Y. Lee et al. "Modular 1mm3 Die-Stacked Sensing Platform ..."JSSC, Jan 2013.

104

106

108

102

100

107

105

103

101

Mainframes

Mainframes

Minicomputers

Minicomputers

Workstations

WorkstationsPersonalComputers

PersonalComputers

Laptops

LaptopsHandhelds

Handhelds

Supercomputers

ScalableClusters

CloudComputing

Internetof Things

Internetof Things

Cloud ComputingI Often requires low-latency,

high-throughput to meet overallapplication requirements

I Increasingly w/ specialized HW

Internet-of-ThingsI Very limited resource constraints

(e.g., energy, memory)I Requires carefully managing

these resources to meet overallapplication requirements

I Increasingly w/ specialized HW



Example Application: Image Recognition

Starfish

Dog



Machine Learning (ML): Training vs. Inference

forward"starfish"

Training

many images

Model

=? "dog"

labels

errorbackward

Inferenceforward

"dog"

fewimages



Computer Systems Programming in ML

CloudComputing

Internetof

Things

Google TPUI Training is done using the

TensorFlow C++ frameworkI Training can take weeksI Google TPU is custom chipI High-level ML frameworks use

C++ under the hood

Movidius Myriad 2I Custom chip for ML on

embedded IoT devicesI Carefully crafted C/C++ ML

libraries for inferenceI Embedded control also

in C/C++


What is Computer Systems Programming? Activity Trends in Computer Systems Programming • Course Logistics •







Course Logistics



ECE 2400 Within the Engineering Curriculum


Circuits

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Algorithm

Microarchitecture

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Application

Operating System

Gate Level

Compiler

Technology

ECE 2300 Digital Logic & Computer Org

ECE 3140 Embedded Systems

ECE 4750 Computer Architecture

ECE 4760 Design with Microcontrollers

ECE 2400 Computer Systems Programming

CS 1110 / CS 1112 Intro to Computing

ECE 2400 is also an ENGRD and thus satisfies theengineering distribution requirement

ECE 2400 can be an excellent way to generally incorporateprogramming into your non-ECE engineering curriculum



Course Objectives

I describe a variety of algorithms and data structures and how toanalyze these algorithms and data structures in terms of time andspace complexity

I apply the C/C++ programming languages to implement algorithmsand data structures using different programming paradigms

I evaluate algorithm and data structure alternatives and make acompelling theoretical and/or practical argument for one approach

I create non-trivial C/C++ programs (roughly 1,000 lines of code) andthe associated testing strategy from an English language specification

I write concise yet comprehensive technical reports that describe aprogram implemented in C/C++, explain the testing strategy used toverify functionality, and evaluate the program to characterize itsperformance and memory usage



Course Structure

I Part 1: Procedural Programming. introduction to C, variables, expressions, functions, conditional & iteration

statements, recursion, static types, pointers, arrays, dynamic allocation

I Part 2: Basic Algorithms and Data Structures. lists, vectors, complexity analysis, insertion sort, selection sort, merge sort,

quick sort, hybrid sorts, stacks, queues, sets, maps

I Part 3: Multi-Paradigm Programming. transition to C++, namespaces, flexible function prototypes, references,

exceptions, new/delete, object oriented programming (C++ classes andinheritance for dynamic polymorphism), generic programming (C++templates for static polymorphism), functional programming (C++ functorsand lambdas), concurrent programming (C++ threads and atomics)

I Part 4: More Algorithms and Data Structures. trees (binary trees, binary search trees), tables (lookup tables, hash

tables), graphs



Programming Assignments

I PA1–3: Fundamentals. PA1: Math functions. PA2: List and Vector Data Structures. PA3: Sorting Algorithms

I PA4–5: Handwriting Recognition System. PA5: Linear vs. Binary Searching. PA5: Trees vs. Tables

I Every programming assignment involves. C/C++ “agile” programming. State-of-the-art tools for build systems,

version control, continuous integration,code coverage

. Performance measurement

. Short technical report







Course Staff

I Prof. Batten InstructorI Yanghui Oh ECE PhDI Justin Joco ECE MEngI Mariangel Rivera CS seniorI Grace Zheng CS seniorI Sarah North ECE juniorI Rikako Onuma CS junior

I Course Staff C/C++ Experience. Many upper-level courses which use C/C++. Internship on YouTube image processing application (C). Internship on chip design file format parser (C). Internship on low-latency stock market trade validator (C). Internship on drone detection using optical flow (C++)



Frequently Asked Questions

I I have not taken CS 1110 nor CS 1112, can I take this class?. We assume some basic programming experience, discuss with instructor

I ECE Majors – How does ECE 2400 satisfy degree requirements?. ECE 2400 can count as your second ENGRD course. ECE 2400 can count as an outside-ECE technical elective. ECE 2400 satisfies the ECE advanced programming requirement

I CS Majors – Can I use ECE 2400 in place of CS 2110?. Kind of but you should probably take CS 2110

I ECE/CS Dual Majors – Can I use ECE 2400 in place of CS 2110?. Absolutely! (NEW)

I CS Minors – Can I use ECE 2400 in place of CS 2110?. Absolutely! (NEW)



Frequently Asked Questions

I Other Majors – How does ECE 2400 satisfy degree requirements?. ECE 2400 can count as one of your two required ENGRD courses

I ECE MEngs – How does ECE 2400 satisfy degree requirements?. ECE 2400 can count as a technical elective, but you remember you can

only use on ECE undergraduate course as a technical elective

I Should I take both ECE 2400 and CS 2110?. Sure! (recall popularity and performance data)


What is Computer Systems Programming? Activity Trends in Computer Systems Programming Course Logistics



Take-Away Points

I Computer systems programming involvesdeveloping software to connect the low-levelcomputer hardware to high-level, user-facingapplication software and usually requires carefulconsideration of performance and resourceconstraints

I We are entering an exciting era where computersystems programming will play a critical role inenabling both cloud computing and theinternet-of-things


Documents

Course Overview Computer Systems Programming …...C++ under the hood Movidius Myriad 2 I Custom chip for ML on embedded IoT devices I Carefully crafted C/C++ ML libraries for inference