倒数第二行显示overloaded function as left operand，求大神告诉我怎么改

#include <stdio.h>
void  max2( int x1,  int x2  ,int  x3,  int  *y1 ,int  *y2)
    {   if (x1>=x2  && x1>=x3)
                            {   *y1=x1;
                                   if(x2>=x3)     *y2=x2;
                                   else   *y2=x3;
                             }
                      if(x1>=x2 && x1< x3)
                             {   *y1=x3;
                                   if(x1>=x2)  *y2=x1;
                                   else  *y2=x2;
                              }
                      if(x1<x2 && x2>=x3)
                               {   *y1=x2;
                                     if (x1>=x3)  *y2=x1;
                                     else  *y2=x3;
                                }
                      if (x1<x2 && x2<x3)
                                {  *y1=x3;
                                      if(x1>=x2)  *y2=x1;
                                      else  *y2=x2;
                                 }
                 }
        void main(void)
                   {   int  v1=5,v2=9,v3=7,f1,f2;
                          max2=(v1,v2,v3,&f1,&f2);
                            printf("f1=%d ,f2=%d\n",f1,f2);
                   }