struct operation {
  int key;
  int count;
  char *mnem;
  char *oper;
  char *stackcode;
  int disp;
};
struct operation op[2] = {
  {1000, 2, "AST_Add", "+", "ADD", 3},
  {1001, 2, "AST_Sub", "-", "SUB", 3},
};
writenum(op[1].disp);