@Nullable
  private DfaInstructionState[] handleRelationBinop(
      BinopInstruction instruction,
      DataFlowRunner runner,
      DfaMemoryState memState,
      DfaValue dfaRight,
      DfaValue dfaLeft) {
    DfaValueFactory factory = runner.getFactory();
    final Instruction next = runner.getInstruction(instruction.getIndex() + 1);
    DfaRelationValue dfaRelation =
        factory
            .getRelationFactory()
            .createRelation(dfaLeft, dfaRight, instruction.getOperationSign(), false);
    if (dfaRelation == null) {
      return null;
    }

    myCanBeNullInInstanceof.add(instruction);

    ArrayList<DfaInstructionState> states = new ArrayList<DfaInstructionState>();

    final DfaMemoryState trueCopy = memState.createCopy();
    if (trueCopy.applyCondition(dfaRelation)) {
      trueCopy.push(factory.getConstFactory().getTrue());
      instruction.setTrueReachable();
      states.add(new DfaInstructionState(next, trueCopy));
    }

    //noinspection UnnecessaryLocalVariable
    DfaMemoryState falseCopy = memState;
    if (falseCopy.applyCondition(dfaRelation.createNegated())) {
      falseCopy.push(factory.getConstFactory().getFalse());
      instruction.setFalseReachable();
      states.add(new DfaInstructionState(next, falseCopy));
      if (instruction instanceof InstanceofInstruction && !falseCopy.isNull(dfaLeft)) {
        myUsefulInstanceofs.add((InstanceofInstruction) instruction);
      }
    }

    return states.toArray(new DfaInstructionState[states.size()]);
  }
  @Nullable
  private static DfaInstructionState[] handleConstantComparison(
      BinopInstruction instruction,
      DataFlowRunner runner,
      DfaMemoryState memState,
      DfaValue dfaRight,
      DfaValue dfaLeft,
      IElementType opSign) {
    if (dfaRight instanceof DfaConstValue && dfaLeft instanceof DfaVariableValue) {
      Object value = ((DfaConstValue) dfaRight).getValue();
      if (value instanceof Number) {
        DfaInstructionState[] result =
            checkComparingWithConstant(
                instruction,
                runner,
                memState,
                (DfaVariableValue) dfaLeft,
                opSign,
                ((Number) value).doubleValue());
        if (result != null) {
          return result;
        }
      }
    }
    if (dfaRight instanceof DfaVariableValue && dfaLeft instanceof DfaConstValue) {
      return handleConstantComparison(
          instruction,
          runner,
          memState,
          dfaLeft,
          dfaRight,
          DfaRelationValue.getSymmetricOperation(opSign));
    }

    if (EQEQ != opSign && NE != opSign) {
      return null;
    }

    if (dfaLeft instanceof DfaConstValue && dfaRight instanceof DfaConstValue
        || dfaLeft == runner.getFactory().getConstFactory().getContractFail()
        || dfaRight == runner.getFactory().getConstFactory().getContractFail()) {
      boolean negated =
          (NE == opSign)
              ^ (DfaMemoryStateImpl.isNaN(dfaLeft) || DfaMemoryStateImpl.isNaN(dfaRight));
      if (dfaLeft == dfaRight ^ negated) {
        return alwaysTrue(instruction, runner, memState);
      }
      return alwaysFalse(instruction, runner, memState);
    }

    return null;
  }