void BinaryOpExpression::outputCPPImpl(CodeGenerator &cg,
                                       AnalysisResultPtr ar) {

    if (isOpEqual() && outputCPPImplOpEqual(cg, ar)) return;

    bool wrapped = true;
    switch (m_op) {
    case T_CONCAT_EQUAL:
        if (const char *prefix = stringBufferPrefix(cg, ar, m_exp1)) {
            SimpleVariablePtr sv = static_pointer_cast<SimpleVariable>(m_exp1);
            ExpressionPtrVec ev;
            bool hasVoid = false;
            getConcatList(ev, m_exp2, hasVoid);
            cg_printf("%s", stringBufferName(Option::TempPrefix, prefix,
                                             sv->getName().c_str()).c_str());
            outputStringBufExprs(ev, cg, ar);
            return;
        }
        cg_printf("concat_assign");
        break;
    case '.':
    {
        ExpressionPtr self = static_pointer_cast<Expression>(shared_from_this());
        ExpressionPtrVec ev;
        bool hasVoid = false;
        int num = getConcatList(ev, self, hasVoid);
        assert(!hasVoid);
        if (num <= MAX_CONCAT_ARGS) {
            assert(num >= 2);
            if (num == 2) {
                cg_printf("concat(");
            } else {
                if (num > MAX_CONCAT_ARGS) ar->m_concatLengths.insert(num);
                cg_printf("concat%d(", num);
            }
            for (size_t i = 0; i < ev.size(); i++) {
                ExpressionPtr exp = ev[i];
                if (i) cg_printf(", ");
                outputStringExpr(cg, ar, exp, false);
            }
            cg_printf(")");
        } else {
            cg_printf("StringBuffer()");
            outputStringBufExprs(ev, cg, ar);
            cg_printf(".detach()");
        }
    }
    return;
    case T_LOGICAL_XOR:
        cg_printf("logical_xor");
        break;
    case '|':
        cg_printf("bitwise_or");
        break;
    case '&':
        cg_printf("bitwise_and");
        break;
    case '^':
        cg_printf("bitwise_xor");
        break;
    case T_IS_IDENTICAL:
        cg_printf("same");
        break;
    case T_IS_NOT_IDENTICAL:
        cg_printf("!same");
        break;
    case T_IS_EQUAL:
        cg_printf("equal");
        break;
    case T_IS_NOT_EQUAL:
        cg_printf("!equal");
        break;
    case '<':
        cg_printf("less");
        break;
    case T_IS_SMALLER_OR_EQUAL:
        cg_printf("not_more");
        break;
    case '>':
        cg_printf("more");
        break;
    case T_IS_GREATER_OR_EQUAL:
        cg_printf("not_less");
        break;
    case '/':
        cg_printf("divide");
        break;
    case '%':
        cg_printf("modulo");
        break;
    case T_INSTANCEOF:
        cg_printf("instanceOf");
        break;
    default:
        wrapped = !isUnused();
        break;
    }

    if (wrapped) cg_printf("(");

    ExpressionPtr first = m_exp1;
    ExpressionPtr second = m_exp2;

    // we could implement these functions natively on String and Array classes
    switch (m_op) {
    case '+':
    case '-':
    case '*':
    case '/':
        if (!first->outputCPPArithArg(cg, ar, m_op == '+')) {
            TypePtr argType = first->hasCPPTemp() ?
                              first->getType() : first->getActualType();
            bool flag = castIfNeeded(getActualType(), argType, cg, ar, getScope());
            first->outputCPP(cg, ar);
            if (flag) {
                cg_printf(")");
            }
        }
        break;
    case T_SL:
    case T_SR:
        ASSERT(first->getType()->is(Type::KindOfInt64));
        first->outputCPP(cg, ar);
        break;
    default:
        first->outputCPP(cg, ar);
        break;
    }

    switch (m_op) {
    case T_PLUS_EQUAL:
        cg_printf(" += ");
        break;
    case T_MINUS_EQUAL:
        cg_printf(" -= ");
        break;
    case T_MUL_EQUAL:
        cg_printf(" *= ");
        break;
    case T_DIV_EQUAL:
        cg_printf(" /= ");
        break;
    case T_MOD_EQUAL:
        cg_printf(" %%= ");
        break;
    case T_AND_EQUAL:
        cg_printf(" &= ");
        break;
    case T_OR_EQUAL:
        cg_printf(" |= ");
        break;
    case T_XOR_EQUAL:
        cg_printf(" ^= ");
        break;
    case T_SL_EQUAL:
        cg_printf(" <<= ");
        break;
    case T_SR_EQUAL:
        cg_printf(" >>= ");
        break;
    case T_BOOLEAN_OR:
        cg_printf(" || ");
        break;
    case T_BOOLEAN_AND:
        cg_printf(" && ");
        break;
    case T_LOGICAL_OR:
        cg_printf(" || ");
        break;
    case T_LOGICAL_AND:
        cg_printf(" && ");
        break;
    default:
        switch (m_op) {
        case '+':
            cg_printf(" + ");
            break;
        case '-':
            cg_printf(" - ");
            break;
        case '*':
            cg_printf(" * ");
            break;
        case T_SL:
            cg_printf(" << ");
            break;
        case T_SR:
            cg_printf(" >> ");
            break;
        default:
            cg_printf(", ");
            break;
        }
        break;
    }

    switch (m_op) {
    case '+':
    case '-':
    case '*':
    case '/':
        if (!second->outputCPPArithArg(cg, ar, m_op == '+')) {
            TypePtr argType = second->hasCPPTemp() ?
                              second->getType() : second->getActualType();
            bool flag = castIfNeeded(getActualType(), argType, cg, ar, getScope());
            second->outputCPP(cg, ar);
            if (flag) {
                cg_printf(")");
            }
        }
        break;
    case T_INSTANCEOF:
    {
        if (second->isScalar()) {
            ScalarExpressionPtr scalar =
                dynamic_pointer_cast<ScalarExpression>(second);
            bool notQuoted = scalar && !scalar->isQuoted();
            std::string s = second->getLiteralString();
            if (s == "static" && notQuoted) {
                cg_printf("FrameInjection::GetStaticClassName(fi.getThreadInfo())");
            } else if (s != "") {
                if (s == "self" && notQuoted) {
                    ClassScopeRawPtr cls = getOriginalClass();
                    if (cls) {
                        s = cls->getOriginalName();
                    }
                } else if (s == "parent" && notQuoted) {
                    ClassScopeRawPtr cls = getOriginalClass();
                    if (cls && !cls->getParent().empty()) {
                        s = cls->getParent();
                    }
                }
                cg_printString(s, ar, shared_from_this());
            } else {
                second->outputCPP(cg, ar);
            }
        } else {
            second->outputCPP(cg, ar);
        }
        break;
    }
    case T_PLUS_EQUAL:
    case T_MINUS_EQUAL:
    case T_MUL_EQUAL:
    {
        TypePtr t1 = first->getCPPType();
        TypePtr t2 = second->getType();
        if (t1 && !t1->is(Type::KindOfArray) &&
                t2 && Type::IsCastNeeded(ar, t2, t1)) {
            t1->outputCPPCast(cg, ar, getScope());
            cg_printf("(");
            second->outputCPP(cg, ar);
            cg_printf(")");
        } else {
            second->outputCPP(cg, ar);
        }
        break;
    }
    case T_BOOLEAN_OR:
    case T_BOOLEAN_AND:
    case T_LOGICAL_AND:
    case T_LOGICAL_OR:
        if (isUnused()) {
            cg_printf("(");
            if (second->outputCPPUnneeded(cg, ar)) {
                cg_printf(",");
            }
            cg_printf("false)");
        } else {
            second->outputCPP(cg, ar);
        }
        break;
    default:
        second->outputCPP(cg, ar);
    }

    if (wrapped) cg_printf(")");
}