failFormat("expected log10(%s, UNNECESSARY) = %s; got ArithmeticException", x, floor);
        }
      }
    }
  }

  @GwtIncompatible // TODO
  public void testLog10TrivialOnPowerOf10() {
    long x = 1000000000000L;
    for (RoundingMode mode : ALL_ROUNDING_MODES) {
      assertEquals(12, LongMath.log10(x, mode));
    }
  }

  @GwtIncompatible // TODO