* can narrow the possible floor(log10(x)) values to two. For example, if floor(log2(x)) is 6,
     * then 64 <= x < 128, so floor(log10(x)) is either 1 or 2.
     */
    int y = maxLog10ForLeadingZeros[Long.numberOfLeadingZeros(x)];
    /*
     * y is the higher of the two possible values of floor(log10(x)). If x < 10^y, then we want the

  @GwtIncompatible // TODO
  public void testLog10MatchesBigInteger() {
    for (long x : POSITIVE_LONG_CANDIDATES) {
      for (RoundingMode mode : ALL_SAFE_ROUNDING_MODES) {
        assertEquals(BigIntegerMath.log10(valueOf(x), mode), LongMath.log10(x, mode));
      }
    }
  }

  // Relies on the correctness of log10(long, FLOOR) and of pow(long, int).
  @GwtIncompatible // TODO

pkg math, func J1(float64) float64
pkg math, func Jn(int, float64) float64
pkg math, func Ldexp(float64, int) float64
pkg math, func Lgamma(float64) (float64, int)
pkg math, func Log(float64) float64
pkg math, func Log10(float64) float64
pkg math, func Log1p(float64) float64
pkg math, func Log2(float64) float64
pkg math, func Logb(float64) float64
pkg math, func Max(float64, float64) float64