presto-main/src/main/java/io/prestosql/type/RealOperators.java/RealOperators/negate
class RealOperators:    @ScalarOperator(NEGATION)
    @SqlType(StandardTypes.REAL)
    public static long negate(@SqlType(StandardTypes.REAL) long value)
    {
        return floatToRawIntBits(-intBitsToFloat((int) value));
    }