This PPT covers the entire topic of Macro Assembler. This Includes the topic such as design of a macro assembler, 3 passes of macro assembler etc. This is the PPT of System Programming.

1. BIRLA INSTITUE OF TECHNOLOGY,MESRA
JAIPUR CAMPUS
TOPIC : MACRO ASSEMBLER
BY
MEGHAJ KUMAR MALLICK
(MCA/25017/18)
MCA 2ND YEAR, 4TH SEMESTER

2. Design of a Macro Assembler

3. Design of Macro Assembler
• 3 passes in macro Assembler.
Pass 1:
– Macro definition processing.
– SYMTAB construction.
Pass 2:
– Macro expansion.
– Memory allocation & LC processing.
– Processing of Literals.
– Intermediate Code Generation.

4. pass 3:
– Target code Generation.
– Macro processor can be added asa
processor to an assembler.
– It is implemented in pass 1 of the
assembler.
Design of Macro AssembleR

5. Advantages:
– Many functions don’t have to be
implemented twice.
– Less overhead during processing.(by
removing intermediate code)
– More flexibility is available to the
programmer.
Design of Macro AssembleR

6. Disadvantages:
• Combined pass 1 of the assembler &
macro processor may be too large for a
program to fit into core of some
machine.
• Complexity of such program maybe
overwhelming.
Design of Macro AssembleR

7. PAPASSSPASS 1
R
SeSeararcchh
ppsseeuuddoo-o-oppTTablabl
Search
pseudo-op Table
SeSeararcchh
MMacacrroonnamamee TTaablbl
Search
Macro name Table
SeSeararcchh
mmaacchihinnee-o-opp TTbllee
Search
machine-op Table
GGoo ttoo
PAPASSS
S22
Go to
PASS 2Type ?
Process
Process
Pseudo-ops
Process
Machine instruction
Setup macro
stack frame ,etc.
READ
R
R
R
Maccro definition
Found, macro
calls R
Found
Not
Not
End
pseudo-op
Others
Macro
pseudo-op

8. Microsoft Macro Assembler
 MASM is an assembler for the x86 family of microprocessors,
originally produced MS-DOS operating system. The MASM is the
example of high level assembler. It supports following main
features-
i) A wide variety of macro facilities
ii) Structure programming idioms
iii)High level constructions for looping, procedure calls , and
alteration
The later versions of MASM added the capability of producing
program for the windows operating system. The example of this
type is MASM – 32 which work on the program which already
written API based code in windows .

9. Comparison of Macro Processors
Design
Single pass
 every macro must be defined before it is called
 one-pass processor can alternate between macro definition and
macro expansion
 nested macro definitions may be allowed but nested calls are
not
 Two pass
 Pass1: Recognize macro definitions
 Pass2: Recognize macro calls
 nested macro definitions are not allowed

10. Tables generated while macro
processing
The macro processing leads to generation of three
types of tables –
1. DEFTAB – the definition of the macro is stored in
this table.
2. NAMTAB – the name of the macro is stored in
this table.
3. ARGTAB – all the arguments of macro is stored
in this table.