svmc.cpp

简单的虚拟机代码 可以看看！！ ！！ ！！！1

#include "stdafx.h"

using namespace std;

SVMC::SVMC()
:accumulator(0),
counter(0),
instructionRegister(0),
operationCode(0),
operand(0)
{
	for(int i = 0;i < 100;i++)
	{
		memory[i] = 0;
	}
	cout << "*** Welcome to Simpletron! ***" << endl;
	cout << endl << "Simple Virtual Mechine created!" << endl;
}

SVMC::SVMC(const SVMC & value)
{
	if(this == &value)
	{
		return;
	}

	for(int i = 0;i < 100;i++)
	{
		memory[i] = value.memory[i];
	}
	
	accumulator = value.accumulator;
	counter = value.counter;
	instructionRegister = value.instructionRegister;
	operand = value.operand;
	operationCode = value.operationCode;

	cout << "*** Welcome to Simpletron! ***" << endl;
	cout << endl << "*** Simple Virtual Mechine created! ***" << endl;
}

void SVMC::init()
{
	for(int i = 0;i < 100;i++)
	{
		memory[i] = 0;
	}

	accumulator = 0;
	counter = 0;
	instructionRegister = 0;
	operand = 0;
	operationCode = 0;

	cout << endl << "*** Simple Virtual Mechine initiated! ***" << endl;
}

void SVMC::loadInstructions()
{
	init();

	cout << "*** Please enter your program one instruction ***" << endl;
	cout << "*** (or data word) at a time. I will type the ***" << endl;
	cout << "*** location number and a question mark (?).  ***" << endl;
	cout << "*** You then type the word for that location. ***" << endl;
	cout << "*** Type -1 to stop entering your program.    ***" << endl;
	
	do
	{
		int tmp = 0;

		do
		{
			cout << setw(2) << setfill('0') << counter << " ?";
			cin >> tmp;

		}while(tmp < -1 || tmp > 9999);

		memory[counter++] = tmp;

	}while(memory[counter -1] != -1);

	counter = 0;
	cout << "*** Instructions loaded successfully ! ***" << endl;
}

void SVMC::print() const
{
	cout << "*** States ***" << endl;
	cout << "REGISTERS:" << endl;
	cout << setw(20) << left << setfill(' ') << "Accumulator" << setw(5) << internal << showpos << setfill('0') << accumulator << endl;
	cout << setw(20) << left << setfill(' ') << "Counter"  << "   " << setw(2) << noshowpos << internal << setfill('0') <<  counter << endl;
	cout << setw(20) << left << setfill(' ') << "InstructionRegister" << setw(5) << internal << showpos << setfill('0') << instructionRegister << endl;
	cout << setw(20) << left << setfill(' ') << "OperationCode"  << "   " << setw(2) << noshowpos  << internal << setfill('0') <<  operationCode << endl;
	cout << setw(20) << left << setfill(' ') << "Operand"  << "   " << setw(2) << noshowpos  << internal << setfill('0') <<  operand << endl;
	cout << endl << "MEMORY:" << endl << "  ";

	for(int i = 0;i < 10;i++)
	{
		cout << noshowpos << setfill(' ') << setw(5) << i;
	}

	for(int i = 0;i < 100;i++)
	{
		if(i % 10 == 0)
		{
			cout << setw(2) << noshowpos << endl << i;
		}

		cout << setw(5) << setfill('0') << showpos << memory[i];
	}

	cout << endl << "*** finished ***" << endl;
}

bool SVMC::nextMove()
{
	instructionRegister = memory[counter++];
	operationCode = instructionRegister/100;
	operand = instructionRegister%100;

	try
	{
		int tmp = 0;

		switch(operationCode)
		{
		case 10:
			do
			{
				cout << "*** Please enter a data between -9999 and +9999 ***" << endl;
				cin >> tmp;

			}while(tmp < -9999 || tmp > 9999);
			
			memory[operand] = tmp;
			
			cin.ignore();
			break;
		case 11:
			cout << memory[operand];
			break;
		case 20:
			accumulator = memory[operand];
			break;
		case 21:
			memory[operand] = accumulator;
			break;
		case 30:
			accumulator += memory[operand];
			if(accumulator > 9999 || accumulator < -9999)
			{
				cout << "*** ERROR! *** Accumulator Register out of bound at instruction #" << counter << "! ***" << endl;
				print();
				return true;
			}
			break;
		case 31:
			accumulator -= memory[operand];
			if(accumulator > 9999 || accumulator < -9999)
			{
				cout << "*** ERROR! *** Accumulator Register out of bound at instruction #" << counter << "! ***" << endl;
				print();
				return true;
			}
			break;
		case 32:
			accumulator *= memory[operand];
			if(accumulator > 9999 || accumulator < -9999)
			{
				cout << "*** ERROR! *** Accumulator Register out of bound at instruction #" << counter << "! ***" << endl;
				print();
				return true;
			}
			break;
		case 33:
			if(memory[operand] == 0)
			{
				cout << "*** Attempt to divide by zero ***" << endl;
				cout << "*** Simpletron execution abnormally terminated ***" << endl;
				print();
				return true;
			}
			accumulator /= memory[operand];
			break;
		case 40:
			counter = operand;
			break;
		case 41:
			if(accumulator < 0)
			{
				counter = operand;
			}
			break;
		case 42:
			if(accumulator == 0)
			{
				counter = operand;
			}
			break;
		case 43:
			return true;
		default:
			break;
		}
	}
	catch(...)
	{
		cout << "*** ERROR! *** Memory & Instruction ERROR at #" << counter << " ! *** ERROR! ***" << endl;
		print();
		return true;
	}
	return false;
}

void SVMC::excute()
{
	loadInstructions();

	while(!nextMove())
	{
		//print();
		cout << endl;
	}
}