auto M68000::condition(n4 condition) -> bool {
  switch(condition) {
  case  0: return true;   //T
  case  1: return false;  //F
  case  2: return !r.c && !r.z;  //HI
  case  3: return  r.c ||  r.z;  //LS
  case  4: return !r.c;  //CC,HS
  case  5: return  r.c;  //CS,LO
  case  6: return !r.z;  //NE
  case  7: return  r.z;  //EQ
  case  8: return !r.v;  //VC
  case  9: return  r.v;  //VS
  case 10: return !r.n;  //PL
  case 11: return  r.n;  //MI
  case 12: return  r.n ==  r.v;  //GE
  case 13: return  r.n !=  r.v;  //LT
  case 14: return  r.n ==  r.v && !r.z;  //GT
  case 15: return  r.n !=  r.v ||  r.z;  //LE
  }
  unreachable;
}
