1. 课程名 编译原理 Compiling Techniques
浙江大学计算机学院与软件学院
编译原理课程组

2. Information Instructor 李莹 cnliying@zju.edu.cn 13335880866
Teacher Assistant
孙煦雪

3. Text Books
The Dragon Book: Compilers Principles, Techniques, & Tools, Second Edition, Alfred V. Aho
The Tiger Book: Modern Compiler Implementation in C, Andrew Appel

4. Grade Distribution attend class 10% Homework
Class test or Mid-Term Exam
15%
Final during exam period:
65%

5. Course Structure Course has theoretical and practical aspects
Compiling Techniques
Compiler Design

6. Compiler: why? 1940’s The first electronic computers
Programming in machine language
Slow , tedious and error prone
1954 IBM develops the 704
All programming done in assembly
Software costs exceeded hardware costs!

7. Compiler: why? Emerge of higher-level languages
with higher-level notations
more easily programming
Fortran
Scientific computation
Cobol
Business data processing
Lisp
Symbolic computation

8. Higher-level Language
A compiler
For machine
Higher-level Language
Machine Language
For human
Compiler

9. Why Study Compilers Basic idea for constructing translators.
Principle and Techniques reusable in other CS domains.
Influences hardware design, e.g., RISC, VLIW.
Tools (mostly “optimization”) for enhancing software reliability and security.
Excellent software-engineering example --- theory meets practice.
Essential software tool.

10. A compiler
A compiler is a program that can read a program in one language and translate it into an equivalent program in another language
Compiler
Target Program
Source Program
Input
Output

11. A Interpreter
An interpreter directly execute the operations of source program on inputs
Interpreter
Source program
Input
Output

12. A language-processing system

13. The structure Two parts of a compiler operate as a sequence of phases
Analysis, front end
Synthesis,back end
operate as a sequence of phases

14. Lexical Analysis Reads stream of characters
Group the characters into lexemes
For each lexemes, output a Token
<token-name, attribute-value>

15. Syntax Analysis Reads Token stream
Create tree-like intermediate representation (syntax tree)
The grammatical structure of the token stream

16. Semantic Analysis Uses syntax tree information in Symbol table
understand the meaning of program
Too hard for compilers
only check Semantic consistency
Type checking
Type conversions (Coercions)

17. Intermediate Code Geneartion
For portability and reuse
Before generate target program
Generate intermediate representations first
Three address code
Code sequence
One operator
Three operands (max)

18. Code Optimization To improve the intermediate code Run faster
Use less memory
Consume less power

19. Code Generation Takes an intermediate representation as input
Maps it to target language
Registers and memory allocation
Translate IR instructions into machine instructions

20. Symbol-Table Management
An essential function of a compiler
Records
variable names
various attributes of them

21. Passes Several phases may be grouped into a pass
A pass reads an input file and writes an output file
An example of a pass including:
Lexical analysis,
parsing,
semantic analysis
IR generation.

22. Compiler construction tools-1
Some tools could be used to help compiler construction
Parser Generators. automatically produce syntax analyzers from a grammatical description of a programming language.Yacc
Scanner Generators. produce lexical analyzers from a regular-expression description of the tokens of a language.Lex
Syntax-directed translation engines. produce collections of routines for walking a parse tree and generating intermediate code.

23. Compiler construction tools-2
Code-generator generators. produce a code generator from a collection of rules for translating each operation of the intermediate language into the machine language for a target machine.
Data-flow analysis engines. facilitate the gathering of information about how values are transmitted from one part of a program to each other part.
Compiler-construction toolkit. provide an integrated set of routines for constructing various phases of a compiler.

24. The move to Higher-level Languages
First generation languages: machine languages.
Second generation: assembly languages.
Third generation: higher-level languages, Fortran, Cobol, Lisp, C….
Forth generation: languages designed for specific applications, NOMAD, SQL
Fifth generation: logic- and constraint-based languages, Prolog and OPS5

25. Another classification of languages
Imperative
how a computation is to be done
C, C++, C#, Java
Declarative
what computation is to be done
ML, Haskell, Prolog
Von neumann languages
Object-oriented languages
Scripting languages

26. Impacts on Compilers Can help promote the use of high-level languages
Compiler writing is challenging.
A compiler must translate correctly the potentially infinite set of programs

27. Application of Compiler Technology
Implementation of higher-level programming languages
Optimizations for computer architectures
Design of new computer architectures
Program translations
Software productivity tools

28. Optimizations for computer architecture
Parallelism
Multi-core, many-core
VLIW (very long instruction word), issue multiple operations in parallel
Memory hierarchies
Several levels of storage
The closer, the faster
Registers, CPU cache
Main memory
disks

29. Design of new computer architecture
RISC
Specialized architecture
VLIW
SIMD

30. Program translation Binary translation x86 →Sparc x86 →arm
Hardware synthesis
VHDL RTL
Database query interpreters
Compiled simulation

31. Software Productivity Tools
Type checking
Bounds Checking
Memory-Management tools
Code generators

32. Summary Language Processors Compiler Phases
Machine and Assembly languages
Modeling in Compiler Design
Code Optimization
Higher-level Languages
Compilers and Computer Architecture
Software Productivity and Software Security
Programming Language Basics: Scope Rules, Environments, Block Structure, Parameter Passing, Aliasing

33. The end of Lecture01