return UNCHANGED;
return DefUseEffect.UNCHANGED;
  private static byte doubleAdd(OPT_Instruction s) {   if (CF_DOUBLE) {      canonicalizeCommutativeOperator(s);      OPT_Operand op2 = Binary.getVal2(s);      if (op2.isDoubleConstant()) {        double val2 = op2.asDoubleConstant().value;        OPT_Operand op1 = Binary.getVal1(s);        if (op1.isDoubleConstant()) {          // BOTH CONSTANTS: FOLD          double val1 = op1.asDoubleConstant().value;          Move.mutate(s, DOUBLE_MOVE, Binary.getClearResult(s),                       DC(val1 + val2));          return MOVE_FOLDED;        }        if (val2 == 0.0) {          // x + 0.0 is x, even if x is a NaN          Move.mutate(s, DOUBLE_MOVE, Binary.getClearResult(s),                      Binary.getClearVal1(s));          return MOVE_REDUCED;        }      }    }    return UNCHANGED;  }