presto-main/src/main/java/io/prestosql/operator/aggregation/FloatingPointBitsConverterUtil.java/FloatingPointBitsConverterUtil/sortableLongToDouble
class FloatingPointBitsConverterUtil:    public static double sortableLongToDouble(long value)
    {
        value = value ^ (value >> 63) & Long.MAX_VALUE;
        return Double.longBitsToDouble(value);
    }