目标机及寄存器分配.cpp

编译原理-实现目标机的功能及分配功能-用于生成目标代码

#include<iostream>
#include<string>
using namespace std;


class Register
{
public:
	int num;
	int active;
	int Print_Register;
	string str;
};



void set(Register &a, int num)
{ 
	a.active=1;
	a.num=num;
}

void exchange_str_num(string str,int i,int &a,int &b,int i3)
{
	int t,k,key,a1,b1,multiples1,multiples2;
	a1=0;
	b1=0;
	multiples1=1;
	multiples2=10;
	key=1;
	t=i;
	k=i;
	for(t=i;(t>0)&((str[t-1]!='+')&(str[t-1]!='-')&(str[t-1]!='*')&(str[t-1]!='/'));t--)
		{ 
			a1=(str[t-1]-48)*multiples1+a1;
			multiples1=multiples1*10;
		}

	for(k=i;(k<(str.length()-1))&((str[k+1]!='+')&(str[k+1]!='-')&(str[k+1]!='*')&(str[k+1]!='/'));k++)
		{ 
			b1=b1*multiples2+(str[k+1]-48);
	
		}
	
	a=a1;
	b=b1;
	if(i3==1)
	{
	a=a+b;
	b=a-b;
	a=a-b;
	}


} 


void exchange_num_str(string &str,int &i,int c)
{
	string str1,str2;
	int k1,k2,t,k,d,e;

		for(t=i;(t>0)&((str[t-1]!='+')&(str[t-1]!='-')&(str[t-1]!='*')&(str[t-1]!='/'));t--)
		{ 
		}
		k1=t;

		for(k=i;(k<(str.length()-1))&((str[k+1]!='+')&(str[k+1]!='-')&(str[k+1]!='*')&(str[k+1]!='/'));k++)
		{ 	
		}
		k2=k;
		for(int i1=0;i1<k1;i1++)
		{
			str1+=str[i1];
		}
		for(;c>10;)
		{	
		d=c%10;
		c=c/10;
		str2+=char(d+48);
		} 
		str2+=char(c+48);
	
		e=str2.length();
		for(e=e-1;e>=0;e--)
		{    
		str1+=str2[e];
		}
		for(int j=k2+1;j<(str.length());j++)
		{
		str1+=str[j];
		}
		str=str1;
	

}

void  move_num(Register &ax,Register &bx,Register &cx,int &a,int &b)
{ 
	if((ax.Print_Register==1)||(bx.Print_Register==1))
	{
					if(ax.active==0)
						set(ax,b);
					else 
						if(bx.active==0) 
							set(bx,b);
						else 
							if(cx.active==0)
								set(cx,b);
	}
	else
	{
					if(ax.active==0)
					{  
						set(ax,a);
					}
					else 
						if(bx.active==0) 
						{
							set(bx,a);
						}
						else 
							if(cx.active==0)
							{
								set(cx,a);
							}
					if(ax.active==0)
						set(ax,b);
					else 
						if(bx.active==0) 
							set(bx,b);
						else 
							if(cx.active==0)
								set(cx,b);
	}
}

void Print_result(Register &ax,Register &bx,Register &cx,Register &R1,Register &R2,string &str1,string &str2)
{	
	if(cx.active==1)
	{	
		
		str1=bx.str;
		R1=bx;
         
		str2=cx.str;
		R2=cx;
	} 
	else
	{	
		str1=ax.str;
		R1=ax;
         
		str2=bx.str;
		R2=bx;
	}
						
	if((ax.Print_Register==1)||(bx.Print_Register==1))
	{
		cout<<"MOV  "<<str2<<"  "<<R2.num<<endl;
	}
	else 
	{
		cout<<"MOV  "<<str1<<"  "<<R1.num<<endl;
		cout<<"MOV  "<<str2<<"  "<<R2.num<<endl;
		if(R1.str==ax.str)
			ax.Print_Register=1;
		if(R1.str==bx.str)
			bx.Print_Register=1;
		if(R1.str==cx.str)
			cx.Print_Register=1;		
	}
	if(cx.active==1)
	{
		cx.active=0;
	}
	else
	{
		bx.active=0;
	}	
}


int MULDIV(Register &ax,Register &bx,Register &cx,Register &dx,Register &R1,Register &R2,string &str1,string &str2,char str)
{
		if(str=='*')
			{	
				cout<<"MUL  "<<str2<<endl;
				if(str1==ax.str)
				{
					ax.num=R1.num*R2.num;
					return ax.num;
				}
				if(str1==bx.str)
				{
					bx.num=R1.num*R2.num;
					return bx.num;
				}
				if(str1==cx.str)
				{
					cx.num=R1.num*R2.num;
					return cx.num;
				}
				if(str1==dx.str)
				{
					dx.num=R1.num*R2.num;
					return dx.num;
				}
			}
           if(str=='/')
			{	
				cout<<"DIV  "<<str2<<endl;
				if(str1==ax.str)
				{
					ax.num=R1.num/R2.num;
					return ax.num;
				}
				if(str1==bx.str)
				{
					bx.num=R1.num/R2.num;
					return bx.num;
				}
				if(str1==cx.str)
				{
					cx.num=R1.num/R2.num;
					return cx.num;
				}
				if(str1==dx.str)
				{
					dx.num=R1.num/R2.num;
					return dx.num;
				}
			}
}


int ADDSUB(Register &ax,Register &bx,Register &cx,Register &dx,Register &R1,Register &R2,string &str1,string &str2,char str)
{
	  if(str=='+')
			{	
				cout<<"ADD  "<<str1<<"  "<<str2<<endl;
				if(str1==ax.str)
				{
					ax.num=R1.num+R2.num;
					return ax.num;
				}
				if(str1==bx.str)
				{
					bx.num=R1.num+R2.num;
					return bx.num;
				}
				if(str1==cx.str)
				{
					cx.num=R1.num+R2.num;
					return cx.num;
				}
				if(str1==dx.str)
				{
					dx.num=R1.num+R2.num;
					return dx.num;
				}
			}
	    if(str=='-')
			{	
				cout<<"SUB  "<<str1<<"  "<<str2<<endl;
				if(str1==ax.str)
				{
					ax.num=R1.num-R2.num;
					return ax.num;
				}
				if(str1==bx.str)
				{
					bx.num=R1.num-R2.num;
					return bx.num;
				}
				if(str1==cx.str)
				{
					cx.num=R1.num-R2.num;
					return cx.num;
				}
				if(str1==dx.str)
				{
					dx.num=R1.num-R2.num;
					return dx.num;
				}
			}
}



void Result(Register ax,Register bx,Register cx,Register dx)
{
	    cout<<"AX="<<ax.num<<"  ";
		cout<<"BX="<<bx.num<<"  ";
		cout<<"CX="<<cx.num<<"  ";
		cout<<"DX="<<dx.num<<endl<<endl;
}


void main()
{
	string str,str1,str2,str3;
	Register ax,bx,cx,dx,R1,R2;
	int a,b,c;

	ax.str="AX";
	bx.str="BX";
	cx.str="CX";
	dx.str="DX";

	ax.active=0;
	bx.active=0;
	cx.active=0;
	dx.active=0;

	ax.num=0;
	bx.num=0;
	cx.num=0;
	dx.num=0;

	ax.Print_Register=0;
	bx.Print_Register=0;
	cx.Print_Register=0;
	dx.Print_Register=0;
                                                                                                                                                                                                                                                                                                                                                                                                                              
	cout<<"***********************************************************************"<<endl;
	cout<<"*****************       生成目标代码，分配寄存器          *************"<<endl;
	cout<<"***********************************************************************"<<endl;

	cout<<"请输入您想转换的表达式："<<endl;
	getline(cin,str);
	int i3=0;
	int time=0;
	for(int i=0;i<str.length();i++)
	{   
		
		int g1=0;
	        
		if ((str[i]=='*')||(str[i]=='/'))
		{  	
			for(int g=i;g>0;g--)
			{
				if(str[g]=='+')
				g1=1;
			}
		if((g1==1)&(time>0))
			{	
			cout<<"MOV CX AX"<<endl;
			cx.num=ax.num;
			ax.active=0;
			ax.Print_Register=0;
			bx.Print_Register=0;
			}
		exchange_str_num(str,i,a,b,i3); 
	    move_num(ax,bx,cx,a,b);
		Print_result(ax,bx,cx,R1,R2,str1,str2);
		c=MULDIV(ax,bx,cx,dx,R1,R2,str1,str2,str[i]);
		Result(ax,bx,cx,dx);	
		
		for(int i2=i;i2>0;i2--)
		{
			if((str[i2]=='+')||(str[i2]=='-'))
			{
					i3=1;
					i2=0;	
			}
		
		}		
		exchange_num_str(str,i,c);
		i=0;
		}
		time++;
	}

	for(int j=0;j<str.length();j++)
	{   
		if ((str[j]=='+')||(str[j]=='-'))
		{ 
			exchange_str_num(str,j,a,b,i3); 
		    move_num(ax,bx,cx,a,b);
			Print_result(ax,bx,cx,R1,R2,str1,str2);	
			c=ADDSUB(ax,bx,cx,dx,R1,R2,str1,str2,str[j]);
			Result(ax,bx,cx,dx);	
			exchange_num_str(str,j,c);
			j=0;
		}

	}
}