#include <stdlib.h>
#include <stdio.h>

typedef int (*foo_t)(int);

int foo_dis1(int x, unsigned s);
int foo_dis2(int x, unsigned s);
int foo_btree(int x, unsigned s);
int foo_btree1(int x, unsigned s);
extern const foo_t foos[];

#define N 100000000

int main(int argc, char *argv[])
{
  if (argc != 3) {
    fprintf(stderr,"Usage: %s <dispatch method> <function>\n",argv[0]);
    fprintf(stderr,"  dispatch method: 0=indirect call; 1=binary search,\n\
    2=bounds-check indirect call, 3=b-tree-like 2-level; 4=b-tree-like 1-level\n");
    exit (1);
  }
  char dispatch = argv[1][0];
  int function = atoi(argv[2]);
  int x=1;
  switch (dispatch) {
  case '0':
    for (long i=0; i<N; i++)
      x=(*(foos[function]))(x);
    break;
  case '1':
    for (long i=0; i<N; i++)
      x=foo_dis1(x,function);
    break;
  case '2':
    for (long i=0; i<N; i++)
      x=foo_dis2(x,function);
    break;
  case '3':
    for (long i=0; i<N; i++)
      x=foo_btree(x,function);
    break;
  case '4':
    for (long i=0; i<N; i++)
      x=foo_btree1(x,function);
    break;
  }
  return 0;
}

int foo0(int x)
{
  return x+1;
}
    
int foo1(int x)
{
  return x-1;
}
    
int foo2(int x)
{
  return x+2;
}
    
int foo3(int x)
{
  return x-2;
}
    
int foo4(int x)
{
  return x+3;
}
    
int foo5(int x)
{
  return x-3;
}
    
int foo6(int x)
{
  return x+4;
}

int foo7(int x)
{
  return x-4;
}