public static Type getCmpType()

in fe/fe-common/src/main/java/org/apache/doris/catalog/Type.java [2065:2173]
100 lines of code
62 McCabe index (conditional complexity)

    public static Type getCmpType(Type t1, Type t2, boolean enableDecimal256) {
        if (t1.getPrimitiveType() == PrimitiveType.NULL_TYPE) {
            return t2;
        }
        if (t2.getPrimitiveType() == PrimitiveType.NULL_TYPE) {
            return t1;
        }

        PrimitiveType t1ResultType = t1.getResultType().getPrimitiveType();
        PrimitiveType t2ResultType = t2.getResultType().getPrimitiveType();
        if (canCompareDate(t1.getPrimitiveType(), t2.getPrimitiveType())) {
            return getDateComparisonResultType((ScalarType) t1, (ScalarType) t2);
        }

        // Following logical is compatible with MySQL.
        if (t1ResultType == PrimitiveType.VARCHAR && t2ResultType == PrimitiveType.VARCHAR) {
            return Type.VARCHAR;
        }
        if ((t1ResultType == PrimitiveType.STRING && t2ResultType == PrimitiveType.STRING)
                || (t1ResultType == PrimitiveType.STRING && t2ResultType == PrimitiveType.VARCHAR)
                || (t1ResultType == PrimitiveType.VARCHAR && t2ResultType == PrimitiveType.STRING)) {
            return Type.STRING;
        }
        // TODO(wzy): support NUMERIC/CHAR cast to JSONB
        if (t1ResultType == PrimitiveType.JSONB && t2ResultType == PrimitiveType.JSONB) {
            return Type.JSONB;
        }
        if ((t1ResultType == PrimitiveType.JSONB && t2ResultType == PrimitiveType.VARCHAR)
                || (t1ResultType == PrimitiveType.VARCHAR && t2ResultType == PrimitiveType.JSONB)) {
            return Type.VARCHAR;
        }
        if ((t1ResultType == PrimitiveType.JSONB && t2ResultType == PrimitiveType.STRING)
                || (t1ResultType == PrimitiveType.STRING && t2ResultType == PrimitiveType.JSONB)) {
            return Type.STRING;
        }

        // VARIANT
        if (t1ResultType == PrimitiveType.VARIANT && t2ResultType == PrimitiveType.VARIANT) {
            return Type.VARIANT;
        }
        if ((t1ResultType == PrimitiveType.VARIANT && t2ResultType == PrimitiveType.VARCHAR)
                || (t1ResultType == PrimitiveType.VARCHAR && t2ResultType == PrimitiveType.VARIANT)) {
            return Type.VARCHAR;
        }
        if ((t1ResultType == PrimitiveType.VARIANT && t2ResultType == PrimitiveType.STRING)
                || (t1ResultType == PrimitiveType.STRING && t2ResultType == PrimitiveType.VARIANT)) {
            return Type.STRING;
        }

        // int family type and char family type should cast to char family type
        if ((t1.getPrimitiveType().isFixedPointType() && t2.getPrimitiveType().isCharFamily())
                || (t2.getPrimitiveType().isFixedPointType() && t1.getPrimitiveType().isCharFamily())) {
            return Type.VARCHAR;
        }

        if (t1ResultType == PrimitiveType.BIGINT && t2ResultType == PrimitiveType.BIGINT) {
            return getAssignmentCompatibleType(t1, t2, false, enableDecimal256);
        }
        if (t1.getPrimitiveType().isDecimalV3Type() && t2.getPrimitiveType().isDecimalV3Type()) {
            int resultPrecision = Math.max(t1.getPrecision(), t2.getPrecision());
            PrimitiveType resultDecimalType;
            if (resultPrecision <= ScalarType.MAX_DECIMAL32_PRECISION) {
                resultDecimalType = PrimitiveType.DECIMAL32;
            } else if (resultPrecision <= ScalarType.MAX_DECIMAL64_PRECISION) {
                resultDecimalType = PrimitiveType.DECIMAL64;
            } else {
                resultDecimalType = PrimitiveType.DECIMAL128;
            }
            if (resultPrecision <= ScalarType.MAX_DECIMAL128_PRECISION) {
                return ScalarType.createDecimalType(resultDecimalType, resultPrecision, Math.max(
                        ((ScalarType) t1).getScalarScale(), ((ScalarType) t2).getScalarScale()));
            } else {
                if (enableDecimal256) {
                    return ScalarType.createDecimalType(resultDecimalType, resultPrecision, Math.max(
                            ((ScalarType) t1).getScalarScale(), ((ScalarType) t2).getScalarScale()));
                } else {
                    return Type.DOUBLE;
                }
            }
        }
        if (t1ResultType.isDecimalV3Type() || t2ResultType.isDecimalV3Type()) {
            return getAssignmentCompatibleType(t1, t2, false, enableDecimal256);
        }
        if ((t1ResultType == PrimitiveType.BIGINT
                || t1ResultType == PrimitiveType.DECIMALV2)
                && (t2ResultType == PrimitiveType.BIGINT
                || t2ResultType == PrimitiveType.DECIMALV2)) {
            return Type.DECIMALV2;
        }
        if ((t1ResultType == PrimitiveType.BIGINT
                || t1ResultType == PrimitiveType.LARGEINT)
                && (t2ResultType == PrimitiveType.BIGINT
                || t2ResultType == PrimitiveType.LARGEINT)) {
            return Type.LARGEINT;
        }
        if ((t1ResultType == PrimitiveType.IPV4
                || t1ResultType == PrimitiveType.VARCHAR)
                && (t2ResultType == PrimitiveType.IPV4
                || t2ResultType == PrimitiveType.VARCHAR)) {
            return Type.IPV4;
        }
        if ((t1ResultType == PrimitiveType.IPV6
                || t1ResultType == PrimitiveType.VARCHAR)
                && (t2ResultType == PrimitiveType.IPV6
                || t2ResultType == PrimitiveType.VARCHAR)) {
            return Type.IPV6;
        }
        return Type.DOUBLE;
    }