Method roundToBigInteger

output/java_guava/1.4.16/DoubleMath.java:176–186

(double x, RoundingMode mode)

  // #roundIntermediate, java.lang.Math.getExponent, com.google.common.math.DoubleUtils

  @GwtIncompatible
  public static BigInteger roundToBigInteger(double x, RoundingMode mode) {
    x = roundIntermediate(x, mode);
    if (MIN_LONG_AS_DOUBLE - x < 1.0 & x < MAX_LONG_AS_DOUBLE_PLUS_ONE) {
      return BigInteger.valueOf((long) x);
    }
    int exponent = getExponent(x);
    long significand = getSignificand(x);
    BigInteger result = BigInteger.valueOf(significand).shiftLeft(exponent - SIGNIFICAND_BITS);
    return (x < 0) ? result.negate() : result;
  }

  /**
   * Returns {@code true} if {@code x} is exactly equal to {@code 2^k} for some finite integer