return UNCHANGED;
return DefUseEffect.UNCHANGED;
  private static byte doubleCondMove(OPT_Instruction s) {   {      OPT_Operand val1 = CondMove.getVal1(s);      OPT_Operand val2 = CondMove.getVal2(s);     int cond = CondMove.getCond(s).evaluate(val1, val2);     if (cond != OPT_ConditionOperand.UNKNOWN) {        // BOTH CONSTANTS OR SIMILAR: FOLD        OPT_Operand val =           (cond == OPT_ConditionOperand.TRUE) ? CondMove.getClearTrueValue(s)           : CondMove.getClearFalseValue(s);        Move.mutate(s, DOUBLE_MOVE, CondMove.getClearResult(s), val);        return val.isConstant() ? MOVE_FOLDED : MOVE_REDUCED;     }      if (val1.isConstant() && !val2.isConstant()) {        // Canonicalize by switching operands and fliping code.        OPT_Operand tmp = CondMove.getClearVal1(s);        CondMove.setVal1(s, CondMove.getClearVal2(s));        CondMove.setVal2(s, tmp);        CondMove.getCond(s).flipOperands();      }      OPT_Operand tv = CondMove.getTrueValue(s);      OPT_Operand fv = CondMove.getFalseValue(s);      if (tv.similar(fv)) {        Move.mutate(s, DOUBLE_MOVE, CondMove.getClearResult(s), tv);        return tv.isConstant() ? MOVE_FOLDED : MOVE_REDUCED;      }    }    return UNCHANGED;  }