A macro processor is a fundamental system program designed to streamline the programming process by replacing macro instructions within a source code with their pre-defined sequences of statements. This implementation provides a basic macro processor written in C.
This C program functions by reading an assembly language program that may contain macro definitions and macro calls. The input assembly code is expected to be provided in a file named MACIN.TXT. The core functionality of this processor involves:
Macro Definition Detection: Identifying and parsing macro definitions within the input source code.
Macro Definition Storage: Storing the identified macro definitions in a dedicated data structure known as the Macro Definition Table (MDT).
Macro Expansion: When macro calls are encountered in the input, the processor retrieves the corresponding definition from the MDT and substitutes the macro call with the stored sequence of assembly language statements.
The final expanded assembly code, with all macro calls replaced by their respective bodies, is then written to an output file named MACOUT.TXT. This process effectively automates the expansion of commonly used code blocks, reducing redundancy and improving code readability and maintainability.
In this blog post, we’ll delve into the world of assembly language programming using the 8086 microprocessors. We’ll explore a practical example: creating an assembly program to determine the largest number from a given set of values.
This C++ program demonstrates how to find the largest element from a set of five integers using 8086 assembly instructions embedded directly into the code. The inline assembly helps perform comparisons and updates the result with the highest value found.
This post demonstrates how to sort an array of integers using inline assembly in C++. Here, we perform sorting in ascending order by comparing and swapping adjacent elements using embedded assembly within a C++ program.
#include<iostream.h>
#include<conio.h>
void main()
{
int a[5], x, y;
int i, j;
cout << "\n Enter 5 Numbers:";
for(i = 0; i < 5; i++)
{
cin >> a[i];
}
//Sorting
for(i = 0; i < 4; i++)
{
for(j = 0; j < 4; j++)
{
x = a[j];
y = a[j + 1];
_asm {
mov ax, x
mov bx, y
cmp ax, bx
jl nxt
mov cx, ax
mov ax, bx
mov bx, cx
mov x, ax
mov y, bx
}
nxt:
a[j] = x;
a[j + 1] = y;
}
}
cout << "\n Sorted Array:";
for(i = 0; i < 5; i++)
cout << a[i] << " ";
getch();
}
This C++ program demonstrates how to find the smallest number from an array using inline 8086 assembly language instructions. The logic involves comparing each array element and storing the smallest found so far using cmp and conditional jump instructions.
#include<iostream.h>
#include<conio.h>
void main()
{
short a[5], x, y, res;
short i, j;
y = 999; // Initialize with a large number
cout << "\n Enter 5 Numbers:";
for (i = 0; i < 5; i++) {
cin >> a[i];
}
asm {
mov bx, y
}
// Finding smallest
for (i = 0; i < 5; i++) {
x = a[i];
asm {
mov ax, x
mov bx, y
cmp ax, bx
jnb nxt // Jump if not below (i.e., current is not smaller)
mov bx, ax
mov y, bx
}
nxt:
}
asm {
mov res, bx;
}
cout << "\n Smallest Element:" << res;
getch();
}
In this blog post, we’ll explore how to find the smallest number from a given set of values using an 8086 assembly language program. The following code snippet demonstrates this process:
data segment
STRING1 DB 08h,14h,05h,0Fh,09h
res db ?
data ends
code segment
assume cs:code, ds:data
start: mov ax, data
mov ds, ax
mov cx, 04h
mov bl, 79h
LEA SI, STRING1
up:
mov al, [SI]
cmp al, bl
jge nxt
mov bl, al
nxt:
inc si
dec cx
jnz up
mov res,bl
int 3
code ends
end start
