ppt on phases of compiler

1. NETAJI SUBASH ENGINEERING COLLEGE
PHASES OF COMPILER DESIGN
 Name: AJIT YADAV
 University Roll No. : 10900220033
 Class Roll No.:33
 Sec : A
 Stream : IT
 Registration No.:201090100210082

2. What is compiler?
Compiler is a program which
takes one language as input and
translate it into an equivalent
another language.
Compiler is divided into two parts:
Analysis and Synthesis

3. Phases of compiler
 Conceptually, a compiler operates into phases, each
of which transform the source program from one
representation to another.
 Each phase takes input from its previous stage, has
its own representation of source program, and
feeds its output to the next phase of the compiler.
 The compiler has six phases called as lexical
analyzer, syntax analyzer, semantic analyzer,
intermediate code generator, code optimizer and
code generator.
 Two other activities, symbol-table management
and error handling, are interacting with the six
phases of compiler.

4. Lexical analysis
 The lexical analysis is also known
as scanning.
 It is the phase of compilation in
which the complete source code
is scanned and source program is
broken up into group of strings
called token.
 A token is sequence of character
having a collective meaning.
 E.g. Total = count + rate
 After lexical analysis, the statement
is broken up into series of tokens
as follows:
 identifier total, assignment operato
r, identifier count, plus sign,
identifier rate
syntax analysis
 The syntax analysis is also
known as parsing.
 In this phase token generated
by lexical analysis are grouped
together to form a hierarchical
structure known as syntax tree.

5. semantic analysis
• Once syntax is checked in the syntax
analyzer phase the next phase
i.e. semantic analyzer determines the
meaning of the source string.
• For example meaning of source string
means matching parenthesis, matching
if…else statement, performing arithmetic
operation of expression that are type
compatible or checking operation scope.
Code optimization
 The code optimization phase attempt to
improve the intermediate code
 This is necessary to have a faster executing
code or less consumption of memory
 Thus, by optimizing the code the overall
running time of the target program can be
improved.
Intermediate code generation
 The intermediate code is a kind of
code which is easy to generate
and this code can be easily
converted to target code.
 This code is in variety of form
such as three address code,
quadruple, triple, posix.
Code generation
• In this phase, target code is generated.
•The Intermediate code instructions are
translated into sequence of machine
instruction

6. Thank you