Compiler Design

1. Compiler Design

2.  Group Name : Ethernet
 Topic Name : Compiler Design
 Group Member : 152-15-6232 ( Md. Touhidur Rahman )
152-15-6236 (Sree Joyanto Chandro Barmon)
152-15-6237( Tusher Chandra Ghosh)

3. Index
• Introduction
• Definition
• How it’s work
• Resources
• Question Session

4. What is a Compiler?
A compiler translate texts from one language to other
language.
Programming
Language
(Source)
Compiler
Machine
Language
(Target)

5.  A compiler acts as a translator,
 transforming human-oriented programming languages
into computer-oriented machine languages.
 Ignore machine-dependent details for programmer
What Do Compilers Do ?
 Compilers may generate three types of code:
 Pure Machine Code
 Machine instruction set without assuming the existence of any operating system or library.
 Mostly being OS or embedded applications.
 Augmented Machine Code
 Code with OS routines and runtime support routines.
 More often
 Virtual Machine Code
 Virtual instructions, can be run on any architecture with a virtual machine interpreter or a just-in-time comp
 Ex. Java

6. A Language Processing System

7. Major Tasks
• Any compiler must perform two major tasks
Compiler
Analysis Synthesis
• Analysis of the source program
• Synthesis of a machine-language program

8. The Structure of a Compiler
8
Scanner Parser
Semantic
Routines
Code
Generator
Optimizer
Source
Program Tokens Syntactic
Structure
Symbol and
Attribute
Tables
(Used by all Phases of The Compiler)
(Character Stream)
Intermediate
Representation
Target machine code

9. The Structure of a Compiler
9
Scanner Parser
Semantic
Routines
Code
Generator
Optimizer
Source
Program Tokens Syntactic
Structure
Symbol and
Attribute
Tables
(Used by all
Phases of
The Compiler)
Scanner
 The scanner begins the analysis of the source program
by reading the input, character by character, and
grouping characters into individual words and symbols
(tokens)
 RE ( Regular expression )
 NFA ( Non-deterministic Finite Automata )
 DFA ( Deterministic Finite Automata )
(Character Stream)
Intermediate
Representation
Target machine code

10. The Structure of a Compiler
10
Scanner Parser
Semantic
Routines
Code
Generator
Optimizer
Source
Program Tokens Syntactic
Structure
Symbol and
Attribute
Tables
(Used by all
Phases of
The Compiler)
Parser
 Given a formal syntax specification (typically as a context-
free grammar [CFG] ), the parse reads tokens and groups
them into units as specified by the productions of the
CFG being used.
 As syntactic structure is recognized, the parser either calls
corresponding semantic routines directly or builds a
syntax tree.
 CFG ( Context-Free Grammar )
 GAA ( Grammar Analysis Algorithms )
(Character Stream)
Intermediate
Representation
Target machine code

11. The Structure of a Compiler
11
Scanner Parser
Semantic
Routines
Code
Generator
Optimizer
Source
Program
(Character Stream)
Tokens Syntactic
Structure
Intermediate
Representation
Symbol and
Attribute
Tables
(Used by all
Phases of
The Compiler)
Semantic Routines
 Perform two functions
 Check the static semantics of each construct
 Do the actual translation
 The heart of a compiler
 Syntax Directed Translation
 Semantic Processing Techniques
 IR (Intermediate Representation)
Target machine code

12. The Structure of a Compiler
12
Scanner Parser
Semantic
Routines
Code
Generator
Optimizer
Source
Program Tokens Syntactic
Structure
Symbol and
Attribute
Tables
(Used by all
Phases of
The Compiler)
Optimizer
 The IR code generated by the semantic routines is
analyzed and transformed into functionally equivalent but
improved IR code
 This phase can be very complex and slow
 Peephole optimization
 loop optimization, register allocation, code scheduling
 Register and Temporary Management
 Peephole Optimization
(Character Stream)
Intermediate
Representation
Target machine code

13. The Structure of a Compiler
13
Source
Program
(Character Stream)
Scanner
Tokens
Parser
Syntactic
Structure
Semantic
Routines
Intermediate
Representation
Optimizer
Code
Generator
Code Generator
 Interpretive Code Generation
 Generating Code from Tree/Dag
 Grammar-Based Code Generator
Target machine code

14. The Structure of a Compiler (Example)
14
Scanner
[Lexical Analyzer]
Parser
[Syntax Analyzer]
Semantic Process
[Semantic analyzer]
Code Generator
[Intermediate Code Generator]
Code Optimizer
Tokens
Parse tree
Abstract Syntax Tree Attributes
Non-optimized Intermediate Code
Optimized Intermediate Code
Code Generator
Target machine code
LDF R2,id3
MULF R2,R2,#60.0
LDF R1,id2
ADDF R1,R1,R2
MOVF id1,R1

15. What is NFA and DFA
What is NFA?
 An NFA is a Nondeterministic Finite
Automaton. Nondeterministic means it
can transition to, and be in, multiple
states at once
What is DFA?
 A DFA is a Deterministic Finite
Automaton. Deterministic means that it
can only be in, and transition to, one
state at a time

16. Formal Definition of Nondeterministic Finite Automata.
 An NFA is a five-tuple: N = (S, ∑, δ, S0, F)
 A Finite set of state (S)
 A Set of input symbol (∑)
 A Transition Function (δ)
 The initial/starting state, S0
 A Set of final state F

17. Regular Expression:
State a b
1 {1,2} {1}
2 ϕ {3}
3 ϕ {4}
4 ϕ ϕ
(a|b)* abb
An NFA can easily implemented using a transition table

18. Now we convert the following NFA to DFA
State a b
{1} {1,2} {1}
{1,2} {1,2} {1,3}
{1,3} {1,2} {1,4}
{1,4} {1,2} {1}
Transition Table for DFA

19. Difference Between NFA and DFA
 NFA
 Multiple states Transition at once
 Operator Zero or More
 DFA
 only one state transition in DFA.
 Operator One or More

20. Resources
www.wikipedia.org
www.Google.com
www.tutorialspoint.com
www.slideshare.net