While modern high-level languages like C++ abstract away many low-level operations, sometimes it’s useful to dive into assembly-level instructions for greater control and understanding. This example demonstrates subtraction using inline assembly in C++, with the addition of the DAS instruction to adjust the result for Binary Coded Decimal (BCD) operations.
#include<iostream.h>
#include<conio.h>
#include<stdio.h>
void main() {
clrscr();
int a, b, c;
cout << "Enter First Number:";
cin >> a;
cout << "Enter Second Number:";
cin >> b;
asm mov ax, a // Move 'a' into AX
asm mov bx, b // Move 'b' into BX
asm sub ax, bx // Subtract BX from AX
asm das // Adjust AX for BCD subtraction
asm mov c, ax // Store result in 'c'
cout << "Result:";
cout << c;
getch();
}
While modern high-level languages like C++ abstract away many low-level operations, sometimes it’s useful to get closer to the hardware to understand how things work under the hood. This example demonstrates how to subtract two 16-bit numbers using inline assembly in a simple C++ program.
#include<iostream.h>
#include<conio.h>
#include<stdio.h>
void main() {
clrscr();
int a, b, c;
cout << "Enter First Number:";
cin >> a;
cout << "Enter Second Number:";
cin >> b;
asm mov ax, a // Move 'a' into AX
asm mov bx, b // Move 'b' into BX
asm sub ax, bx // Subtract BX from AX
asm mov c, ax // Store result in 'c'
cout << "Result:";
cout << c;
getch();
}
This blog post will guide you through a C++ program that performs the addition of two numbers using inline assembly. While modern compilers provide high-level arithmetic operations, understanding inline assembly can help in optimizing performance and understanding low-level interactions with the CPU. Let’s explore this step-by-step!
#include<iostream.h>
#include<conio.h>
#include<stdio.h>
void main()
{
clrscr();
short int a, b, c;
cout << "Enter First Number: ";
cin >> a;
cout << "Enter Second Number: ";
cin >> b;
asm mov ax, a
asm mov ah, 00h
asm mov bx, b
asm mov bh, 00h
asm add al, bl
asm mov c, ax
cout << "Result: ";
cout << c;
getch();
}
This C++ program determines whether a given number is even or odd using 8086-style inline assembly. It utilizes the div instruction to divide the number by 2 and then checks the remainder stored in the dx register.
#include<iostream.h>
#include<conio.h>
void main() {
clrscr();
int a, res;
cout << "\n Enter a number";
cin >> a;
asm mov ax, a // Move input number into AX
asm mov bx, 02h // Move divisor 2 into BX
asm div bx // Divide AX by BX, quotient in AX, remainder in DX
asm mov res, dx // Store remainder in res
if(res == 0) {
cout << "\n Even";
} else {
cout << "\n Odd";
}
getch();
}
This program demonstrates how to use inline 8086 assembly in C++ to determine whether a given number is positive or negative. It’s a great way to understand how conditional branching works at the assembly level.
#include<iostream.h>
#include<conio.h>
void main() {
clrscr();
int a;
cout << "\n Enter a number:";
cin >> a;
asm mov ax, 0000h // Clear AX
asm mov ax, a // Move user input into AX
asm cmp ax, 0000h // Compare AX with 0
asm jl less // Jump to 'less' if AX < 0
asm jge greater // Jump to 'greater' if AX >= 0
less:
cout << "\n Number is negative";
asm jmp end
greater:
cout << "\n Number is positive";
end:
getch();
}
This program demonstrates how to calculate the square, cube, or factorial of a number using 8086 inline assembly in C++. It presents a menu-based approach for the user to choose an operation and performs the calculation using the mul instruction in assembly.
This post walks through a C++ program that demonstrates how to perform basic arithmetic operations like multiplication and division using inline assembly. It allows the user to choose between signed/unsigned multiplication and division in a loop until they decide to exit.
