@Test
  public void testFloatValue() {
    Decimal128 quotient = new Decimal128();

    Decimal128 three = new Decimal128(3);
    Decimal128 four = new Decimal128(9);
    Decimal128.divide(three, four, quotient, (short) 38);
    assertEquals(0.3333333333333333f, quotient.floatValue(), 0.00000000001f);

    Decimal128 minusThree = new Decimal128(-3);
    Decimal128.divide(minusThree, four, quotient, (short) 38);
    assertEquals(-0.333333333333333f, quotient.floatValue(), 0.00000000001f);
  }
During earlier code testing, if we found errors, test them here as regression tests.
common/src/test/org/apache/hadoop/hive/common/type/TestDecimal128.java