CS603(C) Compiler Design Unit 4 study material for RGPV CSE 6th Semester. Learn Intermediate Code Generation, Boolean Expressions, Case Statements, Backpatching, Procedure Calls, Basic Blocks, Flow Graphs, Register Allocation, DAG Representation and Peephole Optimization.
Unit 4 explains how a compiler generates intermediate code and prepares it for final machine code generation. This unit covers important concepts like basic blocks, flow graphs, register allocation, DAG representation, backpatching and peephole optimization.
Learn how compiler converts source program into machine-independent intermediate representation.
Understand program structure using leaders, basic blocks and control flow graphs.
Study register allocation, DAG representation and peephole optimization for better code.
Complete syllabus-based topics of Compiler Design Unit 4.
Process of generating machine-independent code between source code and target code.
Common forms include postfix notation, syntax tree, DAG and three-address code.
Intermediate representation where each instruction has at most three addresses or operands.
Code generation for boolean expressions using logical operations and conditional jumps.
Translation of switch or case statements using jump tables or conditional branches.
Technique used to fill jump addresses later when the target address becomes known.
Code generation for procedure calls, parameter passing, return values and activation records.
A sequence of consecutive statements with single entry and single exit point.
Leaders are instructions that begin a basic block, such as first instruction, jump target and instruction after jump.
Graphical representation of control flow between basic blocks in a program.
Process of assigning variables and temporary values to CPU registers for faster execution.
Decides which value should be stored in which register at a particular point of execution.
Directed Acyclic Graph representation of expressions used to identify common subexpressions.
DAG is used to represent computations inside a basic block and remove redundant calculations.
Local optimization technique that improves small sequences of target code instructions.
Includes instruction selection, register allocation, evaluation order and memory management.
Basic Block: A basic block is a sequence of consecutive statements in which control enters only at the beginning
and leaves only at the end.
Use: Basic blocks help in flow graph construction and code optimization.
Important: First instruction, target of jump and instruction following a jump are considered leaders.
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Complete Compiler Design Unit 4 notes for code generation and optimization basics.
Download NotesThese questions are useful for 7 marks and 14 marks answers in RGPV exams.
High-priority topics from Unit 4 based on common RGPV exam patterns.
| Topic | Expected Frequency | Importance |
|---|---|---|
| Intermediate Code Generation | Very High | ⭐⭐⭐⭐⭐ |
| Three Address Code | Very High | ⭐⭐⭐⭐⭐ |
| Boolean Expression Translation | High | ⭐⭐⭐⭐ |
| Backpatching | Very High | ⭐⭐⭐⭐⭐ |
| Basic Blocks | Very High | ⭐⭐⭐⭐⭐ |
| Flow Graphs | High | ⭐⭐⭐⭐⭐ |
| Register Allocation | High | ⭐⭐⭐⭐ |
| DAG Representation | Very High | ⭐⭐⭐⭐⭐ |
| Peephole Optimization | High | ⭐⭐⭐⭐ |
Intermediate code generation converts source program into machine-independent intermediate representation.
Three address code is an intermediate code form where each instruction contains at most three addresses.
Backpatching is a technique used to fill jump target addresses later when they become known.
A basic block is a sequence of statements with one entry point and one exit point.
DAG stands for Directed Acyclic Graph and is used to represent expressions and identify common subexpressions.
Intermediate code generation, three address code, backpatching, basic blocks, flow graphs, DAG and peephole optimization are important.
Intermediate code generation, basic blocks, DAG, backpatching and peephole optimization are frequently asked in RGPV exams.
Unit 4 builds the base for final code generation, machine code generation and code optimization.
Intermediate code, flow graphs and optimization concepts are useful for compiler, system software and language design roles.