Computer Organization Laboratory Work #1.

computer-organization-1.cpp

#include <iostream>
#include <string>

static int calculate(int a, int b, int c, int d)
{
    int result = 0;

    // (4*a + 52 - 9*b) / (c - 84/(d*a))
    __asm {
        ; a * 4
        mov eax, a
        shl eax, 2

        ; a * 4 + 52
        add eax, 52

        ; 9 * b
        mov ebx, b
        imul ebx, 9

        ; a * 4 + 52 - 9 * b
        sub eax, ebx

        push eax

        ; 84 / (d * a)
        mov ebx, d
        imul ebx, a
        mov eax, 84
        cdq
        idiv ebx
        mov ebx, eax

        ; c - 84 / (d * a)
        mov ecx, c
        sub ecx, ebx

        ; Finally.
        pop eax
        cdq
        idiv ecx

        ; Write result.
        mov result, eax
    }

    return result;
}

static int read(std::string message)
{
    int result = 0;
    bool err;

    do
    {
        std::cout << message;
        try
        {
            std::cin >> result;
            if (std::cin.fail())
            {
                std::cin.clear();
                std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
                throw std::invalid_argument("Integer needed. Try again.");
            }
            err = false;
        }
        catch (const std::exception& e)
        {
            std::cout << e.what() << std::endl;
            err = true;
        }
    } while (err);

    return result;
}

int main() // (4*a + 52 - 9*b) / (c - 84/d*a)
{
    int a = read("Enter `a`: ");
    int b = read("Enter `b`: ");
    int c = read("Enter `c`: ");
    int d = read("Enter `d`: ");

    int result = calculate(a, b, c, d);
    // int result = calculate(207, -23, -92, 6);

    std::cout << result << "\n";
}