A Power Point Presentation on macros and macro processor. What is macros and macro processor . Assembly Language Macro Processor PPT

1. PRESENTATION ON MACROS & MACRO PROCESSOR
Submitted To: Submitted By:
Er. Ritika Yaduvanshi Kuldeep Pathak
ID.No.:- E-9965/17
B.Tech.:- 3rd year(C.S.E.)

2. Introduction
• Macro instructions are single line abbreviations for groups of
instructions.
• It allows the programmer to write shorthand version of a
program.
• The macro processor replaces each macro invocation with the
corresponding sequence of statements.

3. Macro Processor
• Recognize macro definitions
• Save the macro definition
• Recognize macro calls
• Expand macro calls
Source
Code
(with macro)
Macro
Processor
Expanded
Code
Compiler or
Assembler
obj

4. Macro Instructions
• Example 1 :-
.
.
.
A 1,DATA Add contents of DATA to register 1
A 2,DATA Add contents of DATA to register 2
A 3,DATA Add contents of DATA to register 3
.
.
.
A 1,DATA Add contents of DATA to register 1
A 2,DATA Add contents of DATA to register 2
A 3,DATA Add contents of DATA to register 3
.
.
.
DATA DC F’5’
.
.
.

5. Macro Instructions
• We attach a name to a sequence by means of a macro
instruction definition.
• Which is Formed in the following manner :
MACRO Start of Definition
[ ] Macro Name
______
______ Sequence to be abbreviated
______
MEND End of Definition

6. Example
.
Source Expended Source
MACRO
INCR
A 1,DATA
A 2,DATA
A 3,DATA
MEND
.
. .
. .
INCR
. A 1,DATA
. A 2,DATA
. A 3,DATA
.
INCR .
. A 1,DATA
. A 2,DATA
. A 3,DATA
DATA DC F’5’
.
.
.

7. Macro Instruction Arguments
• Example 2:
.
.
.
A 1,DATA 1
A 2,DATA 1
A 3,DATA 1
.
.
A 1,DATA 2
A 2,DATA 2
A 3,DATA 2
.
.
.
DATA 1 DC F’5’
DATA 2 DC F’10’
.
.
.

8. Macro Instruction Arguments
• The instruction sequences are very similar but not identical.
• It can be considered to perform the same operation with a
variable parameter or argument.
• It is specified on the macro name line and distinguished by
the ampersand (&).

9. Macro Instruction Arguments
Example :-
Source Expended Source
MACRO
INCR &ARG
A 1,&ARG
A 2,&ARG
A 3,&ARG
MEND
.
. .
. .
INCR DATA1
. A 1,DATA 1
. A 2,DATA 1
. A 3,DATA 1
.
INCR DATA2 .
. A 1,DATA 2
. A 2,DATA 2
. A 3,DATA 2
DATA1 DC F’5’
DATA2 DC F’10’
.
.
.

10. Macro Calls Within Macros
• Macro calls are available to use in other Macros.
• It is called nested macros.
• Macro calls within Macros can involve several levels.

11. Macro Calls Within Macros
• Example 3 :-
MACRO
ADD1 &ARG
L 1,&ARG
A 1,=F ’1’
ST 1,&ARG
MEND
MACRO
ADDS &ARG1,&ARG2,&ARG3
ADD1 &ARG1
ADD1 &ARG2
ADD1 &ARG3
MEND

12. Expansion of the code