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Posted to commits@commons.apache.org by tn...@apache.org on 2015/02/16 23:40:06 UTC

[36/82] [partial] [math] Update for next development iteration: commons-math4

http://git-wip-us.apache.org/repos/asf/commons-math/blob/a7b4803f/src/main/java/org/apache/commons/math3/dfp/Dfp.java
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diff --git a/src/main/java/org/apache/commons/math3/dfp/Dfp.java b/src/main/java/org/apache/commons/math3/dfp/Dfp.java
deleted file mode 100644
index 19d79a8..0000000
--- a/src/main/java/org/apache/commons/math3/dfp/Dfp.java
+++ /dev/null
@@ -1,2882 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.commons.math3.dfp;
-
-import java.util.Arrays;
-
-import org.apache.commons.math3.RealFieldElement;
-import org.apache.commons.math3.exception.DimensionMismatchException;
-import org.apache.commons.math3.util.FastMath;
-
-/**
- *  Decimal floating point library for Java
- *
- *  <p>Another floating point class.  This one is built using radix 10000
- *  which is 10<sup>4</sup>, so its almost decimal.</p>
- *
- *  <p>The design goals here are:
- *  <ol>
- *    <li>Decimal math, or close to it</li>
- *    <li>Settable precision (but no mix between numbers using different settings)</li>
- *    <li>Portability.  Code should be kept as portable as possible.</li>
- *    <li>Performance</li>
- *    <li>Accuracy  - Results should always be +/- 1 ULP for basic
- *         algebraic operation</li>
- *    <li>Comply with IEEE 854-1987 as much as possible.
- *         (See IEEE 854-1987 notes below)</li>
- *  </ol></p>
- *
- *  <p>Trade offs:
- *  <ol>
- *    <li>Memory foot print.  I'm using more memory than necessary to
- *         represent numbers to get better performance.</li>
- *    <li>Digits are bigger, so rounding is a greater loss.  So, if you
- *         really need 12 decimal digits, better use 4 base 10000 digits
- *         there can be one partially filled.</li>
- *  </ol></p>
- *
- *  <p>Numbers are represented  in the following form:
- *  <pre>
- *  n  =  sign &times; mant &times; (radix)<sup>exp</sup>;</p>
- *  </pre>
- *  where sign is &plusmn;1, mantissa represents a fractional number between
- *  zero and one.  mant[0] is the least significant digit.
- *  exp is in the range of -32767 to 32768</p>
- *
- *  <p>IEEE 854-1987  Notes and differences</p>
- *
- *  <p>IEEE 854 requires the radix to be either 2 or 10.  The radix here is
- *  10000, so that requirement is not met, but  it is possible that a
- *  subclassed can be made to make it behave as a radix 10
- *  number.  It is my opinion that if it looks and behaves as a radix
- *  10 number then it is one and that requirement would be met.</p>
- *
- *  <p>The radix of 10000 was chosen because it should be faster to operate
- *  on 4 decimal digits at once instead of one at a time.  Radix 10 behavior
- *  can be realized by adding an additional rounding step to ensure that
- *  the number of decimal digits represented is constant.</p>
- *
- *  <p>The IEEE standard specifically leaves out internal data encoding,
- *  so it is reasonable to conclude that such a subclass of this radix
- *  10000 system is merely an encoding of a radix 10 system.</p>
- *
- *  <p>IEEE 854 also specifies the existence of "sub-normal" numbers.  This
- *  class does not contain any such entities.  The most significant radix
- *  10000 digit is always non-zero.  Instead, we support "gradual underflow"
- *  by raising the underflow flag for numbers less with exponent less than
- *  expMin, but don't flush to zero until the exponent reaches MIN_EXP-digits.
- *  Thus the smallest number we can represent would be:
- *  1E(-(MIN_EXP-digits-1)*4),  eg, for digits=5, MIN_EXP=-32767, that would
- *  be 1e-131092.</p>
- *
- *  <p>IEEE 854 defines that the implied radix point lies just to the right
- *  of the most significant digit and to the left of the remaining digits.
- *  This implementation puts the implied radix point to the left of all
- *  digits including the most significant one.  The most significant digit
- *  here is the one just to the right of the radix point.  This is a fine
- *  detail and is really only a matter of definition.  Any side effects of
- *  this can be rendered invisible by a subclass.</p>
- * @see DfpField
- * @since 2.2
- */
-public class Dfp implements RealFieldElement<Dfp> {
-
-    /** The radix, or base of this system.  Set to 10000 */
-    public static final int RADIX = 10000;
-
-    /** The minimum exponent before underflow is signaled.  Flush to zero
-     *  occurs at minExp-DIGITS */
-    public static final int MIN_EXP = -32767;
-
-    /** The maximum exponent before overflow is signaled and results flushed
-     *  to infinity */
-    public static final int MAX_EXP =  32768;
-
-    /** The amount under/overflows are scaled by before going to trap handler */
-    public static final int ERR_SCALE = 32760;
-
-    /** Indicator value for normal finite numbers. */
-    public static final byte FINITE = 0;
-
-    /** Indicator value for Infinity. */
-    public static final byte INFINITE = 1;
-
-    /** Indicator value for signaling NaN. */
-    public static final byte SNAN = 2;
-
-    /** Indicator value for quiet NaN. */
-    public static final byte QNAN = 3;
-
-    /** String for NaN representation. */
-    private static final String NAN_STRING = "NaN";
-
-    /** String for positive infinity representation. */
-    private static final String POS_INFINITY_STRING = "Infinity";
-
-    /** String for negative infinity representation. */
-    private static final String NEG_INFINITY_STRING = "-Infinity";
-
-    /** Name for traps triggered by addition. */
-    private static final String ADD_TRAP = "add";
-
-    /** Name for traps triggered by multiplication. */
-    private static final String MULTIPLY_TRAP = "multiply";
-
-    /** Name for traps triggered by division. */
-    private static final String DIVIDE_TRAP = "divide";
-
-    /** Name for traps triggered by square root. */
-    private static final String SQRT_TRAP = "sqrt";
-
-    /** Name for traps triggered by alignment. */
-    private static final String ALIGN_TRAP = "align";
-
-    /** Name for traps triggered by truncation. */
-    private static final String TRUNC_TRAP = "trunc";
-
-    /** Name for traps triggered by nextAfter. */
-    private static final String NEXT_AFTER_TRAP = "nextAfter";
-
-    /** Name for traps triggered by lessThan. */
-    private static final String LESS_THAN_TRAP = "lessThan";
-
-    /** Name for traps triggered by greaterThan. */
-    private static final String GREATER_THAN_TRAP = "greaterThan";
-
-    /** Name for traps triggered by newInstance. */
-    private static final String NEW_INSTANCE_TRAP = "newInstance";
-
-    /** Mantissa. */
-    protected int[] mant;
-
-    /** Sign bit: 1 for positive, -1 for negative. */
-    protected byte sign;
-
-    /** Exponent. */
-    protected int exp;
-
-    /** Indicator for non-finite / non-number values. */
-    protected byte nans;
-
-    /** Factory building similar Dfp's. */
-    private final DfpField field;
-
-    /** Makes an instance with a value of zero.
-     * @param field field to which this instance belongs
-     */
-    protected Dfp(final DfpField field) {
-        mant = new int[field.getRadixDigits()];
-        sign = 1;
-        exp = 0;
-        nans = FINITE;
-        this.field = field;
-    }
-
-    /** Create an instance from a byte value.
-     * @param field field to which this instance belongs
-     * @param x value to convert to an instance
-     */
-    protected Dfp(final DfpField field, byte x) {
-        this(field, (long) x);
-    }
-
-    /** Create an instance from an int value.
-     * @param field field to which this instance belongs
-     * @param x value to convert to an instance
-     */
-    protected Dfp(final DfpField field, int x) {
-        this(field, (long) x);
-    }
-
-    /** Create an instance from a long value.
-     * @param field field to which this instance belongs
-     * @param x value to convert to an instance
-     */
-    protected Dfp(final DfpField field, long x) {
-
-        // initialize as if 0
-        mant = new int[field.getRadixDigits()];
-        nans = FINITE;
-        this.field = field;
-
-        boolean isLongMin = false;
-        if (x == Long.MIN_VALUE) {
-            // special case for Long.MIN_VALUE (-9223372036854775808)
-            // we must shift it before taking its absolute value
-            isLongMin = true;
-            ++x;
-        }
-
-        // set the sign
-        if (x < 0) {
-            sign = -1;
-            x = -x;
-        } else {
-            sign = 1;
-        }
-
-        exp = 0;
-        while (x != 0) {
-            System.arraycopy(mant, mant.length - exp, mant, mant.length - 1 - exp, exp);
-            mant[mant.length - 1] = (int) (x % RADIX);
-            x /= RADIX;
-            exp++;
-        }
-
-        if (isLongMin) {
-            // remove the shift added for Long.MIN_VALUE
-            // we know in this case that fixing the last digit is sufficient
-            for (int i = 0; i < mant.length - 1; i++) {
-                if (mant[i] != 0) {
-                    mant[i]++;
-                    break;
-                }
-            }
-        }
-    }
-
-    /** Create an instance from a double value.
-     * @param field field to which this instance belongs
-     * @param x value to convert to an instance
-     */
-    protected Dfp(final DfpField field, double x) {
-
-        // initialize as if 0
-        mant = new int[field.getRadixDigits()];
-        sign = 1;
-        exp = 0;
-        nans = FINITE;
-        this.field = field;
-
-        long bits = Double.doubleToLongBits(x);
-        long mantissa = bits & 0x000fffffffffffffL;
-        int exponent = (int) ((bits & 0x7ff0000000000000L) >> 52) - 1023;
-
-        if (exponent == -1023) {
-            // Zero or sub-normal
-            if (x == 0) {
-                // make sure 0 has the right sign
-                if ((bits & 0x8000000000000000L) != 0) {
-                    sign = -1;
-                }
-                return;
-            }
-
-            exponent++;
-
-            // Normalize the subnormal number
-            while ( (mantissa & 0x0010000000000000L) == 0) {
-                exponent--;
-                mantissa <<= 1;
-            }
-            mantissa &= 0x000fffffffffffffL;
-        }
-
-        if (exponent == 1024) {
-            // infinity or NAN
-            if (x != x) {
-                sign = (byte) 1;
-                nans = QNAN;
-            } else if (x < 0) {
-                sign = (byte) -1;
-                nans = INFINITE;
-            } else {
-                sign = (byte) 1;
-                nans = INFINITE;
-            }
-            return;
-        }
-
-        Dfp xdfp = new Dfp(field, mantissa);
-        xdfp = xdfp.divide(new Dfp(field, 4503599627370496l)).add(field.getOne());  // Divide by 2^52, then add one
-        xdfp = xdfp.multiply(DfpMath.pow(field.getTwo(), exponent));
-
-        if ((bits & 0x8000000000000000L) != 0) {
-            xdfp = xdfp.negate();
-        }
-
-        System.arraycopy(xdfp.mant, 0, mant, 0, mant.length);
-        sign = xdfp.sign;
-        exp  = xdfp.exp;
-        nans = xdfp.nans;
-
-    }
-
-    /** Copy constructor.
-     * @param d instance to copy
-     */
-    public Dfp(final Dfp d) {
-        mant  = d.mant.clone();
-        sign  = d.sign;
-        exp   = d.exp;
-        nans  = d.nans;
-        field = d.field;
-    }
-
-    /** Create an instance from a String representation.
-     * @param field field to which this instance belongs
-     * @param s string representation of the instance
-     */
-    protected Dfp(final DfpField field, final String s) {
-
-        // initialize as if 0
-        mant = new int[field.getRadixDigits()];
-        sign = 1;
-        exp = 0;
-        nans = FINITE;
-        this.field = field;
-
-        boolean decimalFound = false;
-        final int rsize = 4;   // size of radix in decimal digits
-        final int offset = 4;  // Starting offset into Striped
-        final char[] striped = new char[getRadixDigits() * rsize + offset * 2];
-
-        // Check some special cases
-        if (s.equals(POS_INFINITY_STRING)) {
-            sign = (byte) 1;
-            nans = INFINITE;
-            return;
-        }
-
-        if (s.equals(NEG_INFINITY_STRING)) {
-            sign = (byte) -1;
-            nans = INFINITE;
-            return;
-        }
-
-        if (s.equals(NAN_STRING)) {
-            sign = (byte) 1;
-            nans = QNAN;
-            return;
-        }
-
-        // Check for scientific notation
-        int p = s.indexOf("e");
-        if (p == -1) { // try upper case?
-            p = s.indexOf("E");
-        }
-
-        final String fpdecimal;
-        int sciexp = 0;
-        if (p != -1) {
-            // scientific notation
-            fpdecimal = s.substring(0, p);
-            String fpexp = s.substring(p+1);
-            boolean negative = false;
-
-            for (int i=0; i<fpexp.length(); i++)
-            {
-                if (fpexp.charAt(i) == '-')
-                {
-                    negative = true;
-                    continue;
-                }
-                if (fpexp.charAt(i) >= '0' && fpexp.charAt(i) <= '9') {
-                    sciexp = sciexp * 10 + fpexp.charAt(i) - '0';
-                }
-            }
-
-            if (negative) {
-                sciexp = -sciexp;
-            }
-        } else {
-            // normal case
-            fpdecimal = s;
-        }
-
-        // If there is a minus sign in the number then it is negative
-        if (fpdecimal.indexOf("-") !=  -1) {
-            sign = -1;
-        }
-
-        // First off, find all of the leading zeros, trailing zeros, and significant digits
-        p = 0;
-
-        // Move p to first significant digit
-        int decimalPos = 0;
-        for (;;) {
-            if (fpdecimal.charAt(p) >= '1' && fpdecimal.charAt(p) <= '9') {
-                break;
-            }
-
-            if (decimalFound && fpdecimal.charAt(p) == '0') {
-                decimalPos--;
-            }
-
-            if (fpdecimal.charAt(p) == '.') {
-                decimalFound = true;
-            }
-
-            p++;
-
-            if (p == fpdecimal.length()) {
-                break;
-            }
-        }
-
-        // Copy the string onto Stripped
-        int q = offset;
-        striped[0] = '0';
-        striped[1] = '0';
-        striped[2] = '0';
-        striped[3] = '0';
-        int significantDigits=0;
-        for(;;) {
-            if (p == (fpdecimal.length())) {
-                break;
-            }
-
-            // Don't want to run pass the end of the array
-            if (q == mant.length*rsize+offset+1) {
-                break;
-            }
-
-            if (fpdecimal.charAt(p) == '.') {
-                decimalFound = true;
-                decimalPos = significantDigits;
-                p++;
-                continue;
-            }
-
-            if (fpdecimal.charAt(p) < '0' || fpdecimal.charAt(p) > '9') {
-                p++;
-                continue;
-            }
-
-            striped[q] = fpdecimal.charAt(p);
-            q++;
-            p++;
-            significantDigits++;
-        }
-
-
-        // If the decimal point has been found then get rid of trailing zeros.
-        if (decimalFound && q != offset) {
-            for (;;) {
-                q--;
-                if (q == offset) {
-                    break;
-                }
-                if (striped[q] == '0') {
-                    significantDigits--;
-                } else {
-                    break;
-                }
-            }
-        }
-
-        // special case of numbers like "0.00000"
-        if (decimalFound && significantDigits == 0) {
-            decimalPos = 0;
-        }
-
-        // Implicit decimal point at end of number if not present
-        if (!decimalFound) {
-            decimalPos = q-offset;
-        }
-
-        // Find the number of significant trailing zeros
-        q = offset;  // set q to point to first sig digit
-        p = significantDigits-1+offset;
-
-        while (p > q) {
-            if (striped[p] != '0') {
-                break;
-            }
-            p--;
-        }
-
-        // Make sure the decimal is on a mod 10000 boundary
-        int i = ((rsize * 100) - decimalPos - sciexp % rsize) % rsize;
-        q -= i;
-        decimalPos += i;
-
-        // Make the mantissa length right by adding zeros at the end if necessary
-        while ((p - q) < (mant.length * rsize)) {
-            for (i = 0; i < rsize; i++) {
-                striped[++p] = '0';
-            }
-        }
-
-        // Ok, now we know how many trailing zeros there are,
-        // and where the least significant digit is
-        for (i = mant.length - 1; i >= 0; i--) {
-            mant[i] = (striped[q]   - '0') * 1000 +
-                      (striped[q+1] - '0') * 100  +
-                      (striped[q+2] - '0') * 10   +
-                      (striped[q+3] - '0');
-            q += 4;
-        }
-
-
-        exp = (decimalPos+sciexp) / rsize;
-
-        if (q < striped.length) {
-            // Is there possible another digit?
-            round((striped[q] - '0')*1000);
-        }
-
-    }
-
-    /** Creates an instance with a non-finite value.
-     * @param field field to which this instance belongs
-     * @param sign sign of the Dfp to create
-     * @param nans code of the value, must be one of {@link #INFINITE},
-     * {@link #SNAN},  {@link #QNAN}
-     */
-    protected Dfp(final DfpField field, final byte sign, final byte nans) {
-        this.field = field;
-        this.mant    = new int[field.getRadixDigits()];
-        this.sign    = sign;
-        this.exp     = 0;
-        this.nans    = nans;
-    }
-
-    /** Create an instance with a value of 0.
-     * Use this internally in preference to constructors to facilitate subclasses
-     * @return a new instance with a value of 0
-     */
-    public Dfp newInstance() {
-        return new Dfp(getField());
-    }
-
-    /** Create an instance from a byte value.
-     * @param x value to convert to an instance
-     * @return a new instance with value x
-     */
-    public Dfp newInstance(final byte x) {
-        return new Dfp(getField(), x);
-    }
-
-    /** Create an instance from an int value.
-     * @param x value to convert to an instance
-     * @return a new instance with value x
-     */
-    public Dfp newInstance(final int x) {
-        return new Dfp(getField(), x);
-    }
-
-    /** Create an instance from a long value.
-     * @param x value to convert to an instance
-     * @return a new instance with value x
-     */
-    public Dfp newInstance(final long x) {
-        return new Dfp(getField(), x);
-    }
-
-    /** Create an instance from a double value.
-     * @param x value to convert to an instance
-     * @return a new instance with value x
-     */
-    public Dfp newInstance(final double x) {
-        return new Dfp(getField(), x);
-    }
-
-    /** Create an instance by copying an existing one.
-     * Use this internally in preference to constructors to facilitate subclasses.
-     * @param d instance to copy
-     * @return a new instance with the same value as d
-     */
-    public Dfp newInstance(final Dfp d) {
-
-        // make sure we don't mix number with different precision
-        if (field.getRadixDigits() != d.field.getRadixDigits()) {
-            field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-            final Dfp result = newInstance(getZero());
-            result.nans = QNAN;
-            return dotrap(DfpField.FLAG_INVALID, NEW_INSTANCE_TRAP, d, result);
-        }
-
-        return new Dfp(d);
-
-    }
-
-    /** Create an instance from a String representation.
-     * Use this internally in preference to constructors to facilitate subclasses.
-     * @param s string representation of the instance
-     * @return a new instance parsed from specified string
-     */
-    public Dfp newInstance(final String s) {
-        return new Dfp(field, s);
-    }
-
-    /** Creates an instance with a non-finite value.
-     * @param sig sign of the Dfp to create
-     * @param code code of the value, must be one of {@link #INFINITE},
-     * {@link #SNAN},  {@link #QNAN}
-     * @return a new instance with a non-finite value
-     */
-    public Dfp newInstance(final byte sig, final byte code) {
-        return field.newDfp(sig, code);
-    }
-
-    /** Get the {@link org.apache.commons.math3.Field Field} (really a {@link DfpField}) to which the instance belongs.
-     * <p>
-     * The field is linked to the number of digits and acts as a factory
-     * for {@link Dfp} instances.
-     * </p>
-     * @return {@link org.apache.commons.math3.Field Field} (really a {@link DfpField}) to which the instance belongs
-     */
-    public DfpField getField() {
-        return field;
-    }
-
-    /** Get the number of radix digits of the instance.
-     * @return number of radix digits
-     */
-    public int getRadixDigits() {
-        return field.getRadixDigits();
-    }
-
-    /** Get the constant 0.
-     * @return a Dfp with value zero
-     */
-    public Dfp getZero() {
-        return field.getZero();
-    }
-
-    /** Get the constant 1.
-     * @return a Dfp with value one
-     */
-    public Dfp getOne() {
-        return field.getOne();
-    }
-
-    /** Get the constant 2.
-     * @return a Dfp with value two
-     */
-    public Dfp getTwo() {
-        return field.getTwo();
-    }
-
-    /** Shift the mantissa left, and adjust the exponent to compensate.
-     */
-    protected void shiftLeft() {
-        for (int i = mant.length - 1; i > 0; i--) {
-            mant[i] = mant[i-1];
-        }
-        mant[0] = 0;
-        exp--;
-    }
-
-    /* Note that shiftRight() does not call round() as that round() itself
-     uses shiftRight() */
-    /** Shift the mantissa right, and adjust the exponent to compensate.
-     */
-    protected void shiftRight() {
-        for (int i = 0; i < mant.length - 1; i++) {
-            mant[i] = mant[i+1];
-        }
-        mant[mant.length - 1] = 0;
-        exp++;
-    }
-
-    /** Make our exp equal to the supplied one, this may cause rounding.
-     *  Also causes de-normalized numbers.  These numbers are generally
-     *  dangerous because most routines assume normalized numbers.
-     *  Align doesn't round, so it will return the last digit destroyed
-     *  by shifting right.
-     *  @param e desired exponent
-     *  @return last digit destroyed by shifting right
-     */
-    protected int align(int e) {
-        int lostdigit = 0;
-        boolean inexact = false;
-
-        int diff = exp - e;
-
-        int adiff = diff;
-        if (adiff < 0) {
-            adiff = -adiff;
-        }
-
-        if (diff == 0) {
-            return 0;
-        }
-
-        if (adiff > (mant.length + 1)) {
-            // Special case
-            Arrays.fill(mant, 0);
-            exp = e;
-
-            field.setIEEEFlagsBits(DfpField.FLAG_INEXACT);
-            dotrap(DfpField.FLAG_INEXACT, ALIGN_TRAP, this, this);
-
-            return 0;
-        }
-
-        for (int i = 0; i < adiff; i++) {
-            if (diff < 0) {
-                /* Keep track of loss -- only signal inexact after losing 2 digits.
-                 * the first lost digit is returned to add() and may be incorporated
-                 * into the result.
-                 */
-                if (lostdigit != 0) {
-                    inexact = true;
-                }
-
-                lostdigit = mant[0];
-
-                shiftRight();
-            } else {
-                shiftLeft();
-            }
-        }
-
-        if (inexact) {
-            field.setIEEEFlagsBits(DfpField.FLAG_INEXACT);
-            dotrap(DfpField.FLAG_INEXACT, ALIGN_TRAP, this, this);
-        }
-
-        return lostdigit;
-
-    }
-
-    /** Check if instance is less than x.
-     * @param x number to check instance against
-     * @return true if instance is less than x and neither are NaN, false otherwise
-     */
-    public boolean lessThan(final Dfp x) {
-
-        // make sure we don't mix number with different precision
-        if (field.getRadixDigits() != x.field.getRadixDigits()) {
-            field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-            final Dfp result = newInstance(getZero());
-            result.nans = QNAN;
-            dotrap(DfpField.FLAG_INVALID, LESS_THAN_TRAP, x, result);
-            return false;
-        }
-
-        /* if a nan is involved, signal invalid and return false */
-        if (isNaN() || x.isNaN()) {
-            field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-            dotrap(DfpField.FLAG_INVALID, LESS_THAN_TRAP, x, newInstance(getZero()));
-            return false;
-        }
-
-        return compare(this, x) < 0;
-    }
-
-    /** Check if instance is greater than x.
-     * @param x number to check instance against
-     * @return true if instance is greater than x and neither are NaN, false otherwise
-     */
-    public boolean greaterThan(final Dfp x) {
-
-        // make sure we don't mix number with different precision
-        if (field.getRadixDigits() != x.field.getRadixDigits()) {
-            field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-            final Dfp result = newInstance(getZero());
-            result.nans = QNAN;
-            dotrap(DfpField.FLAG_INVALID, GREATER_THAN_TRAP, x, result);
-            return false;
-        }
-
-        /* if a nan is involved, signal invalid and return false */
-        if (isNaN() || x.isNaN()) {
-            field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-            dotrap(DfpField.FLAG_INVALID, GREATER_THAN_TRAP, x, newInstance(getZero()));
-            return false;
-        }
-
-        return compare(this, x) > 0;
-    }
-
-    /** Check if instance is less than or equal to 0.
-     * @return true if instance is not NaN and less than or equal to 0, false otherwise
-     */
-    public boolean negativeOrNull() {
-
-        if (isNaN()) {
-            field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-            dotrap(DfpField.FLAG_INVALID, LESS_THAN_TRAP, this, newInstance(getZero()));
-            return false;
-        }
-
-        return (sign < 0) || ((mant[mant.length - 1] == 0) && !isInfinite());
-
-    }
-
-    /** Check if instance is strictly less than 0.
-     * @return true if instance is not NaN and less than or equal to 0, false otherwise
-     */
-    public boolean strictlyNegative() {
-
-        if (isNaN()) {
-            field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-            dotrap(DfpField.FLAG_INVALID, LESS_THAN_TRAP, this, newInstance(getZero()));
-            return false;
-        }
-
-        return (sign < 0) && ((mant[mant.length - 1] != 0) || isInfinite());
-
-    }
-
-    /** Check if instance is greater than or equal to 0.
-     * @return true if instance is not NaN and greater than or equal to 0, false otherwise
-     */
-    public boolean positiveOrNull() {
-
-        if (isNaN()) {
-            field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-            dotrap(DfpField.FLAG_INVALID, LESS_THAN_TRAP, this, newInstance(getZero()));
-            return false;
-        }
-
-        return (sign > 0) || ((mant[mant.length - 1] == 0) && !isInfinite());
-
-    }
-
-    /** Check if instance is strictly greater than 0.
-     * @return true if instance is not NaN and greater than or equal to 0, false otherwise
-     */
-    public boolean strictlyPositive() {
-
-        if (isNaN()) {
-            field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-            dotrap(DfpField.FLAG_INVALID, LESS_THAN_TRAP, this, newInstance(getZero()));
-            return false;
-        }
-
-        return (sign > 0) && ((mant[mant.length - 1] != 0) || isInfinite());
-
-    }
-
-    /** Get the absolute value of instance.
-     * @return absolute value of instance
-     * @since 3.2
-     */
-    public Dfp abs() {
-        Dfp result = newInstance(this);
-        result.sign = 1;
-        return result;
-    }
-
-    /** Check if instance is infinite.
-     * @return true if instance is infinite
-     */
-    public boolean isInfinite() {
-        return nans == INFINITE;
-    }
-
-    /** Check if instance is not a number.
-     * @return true if instance is not a number
-     */
-    public boolean isNaN() {
-        return (nans == QNAN) || (nans == SNAN);
-    }
-
-    /** Check if instance is equal to zero.
-     * @return true if instance is equal to zero
-     */
-    public boolean isZero() {
-
-        if (isNaN()) {
-            field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-            dotrap(DfpField.FLAG_INVALID, LESS_THAN_TRAP, this, newInstance(getZero()));
-            return false;
-        }
-
-        return (mant[mant.length - 1] == 0) && !isInfinite();
-
-    }
-
-    /** Check if instance is equal to x.
-     * @param other object to check instance against
-     * @return true if instance is equal to x and neither are NaN, false otherwise
-     */
-    @Override
-    public boolean equals(final Object other) {
-
-        if (other instanceof Dfp) {
-            final Dfp x = (Dfp) other;
-            if (isNaN() || x.isNaN() || field.getRadixDigits() != x.field.getRadixDigits()) {
-                return false;
-            }
-
-            return compare(this, x) == 0;
-        }
-
-        return false;
-
-    }
-
-    /**
-     * Gets a hashCode for the instance.
-     * @return a hash code value for this object
-     */
-    @Override
-    public int hashCode() {
-        return 17 + (sign << 8) + (nans << 16) + exp + Arrays.hashCode(mant);
-    }
-
-    /** Check if instance is not equal to x.
-     * @param x number to check instance against
-     * @return true if instance is not equal to x and neither are NaN, false otherwise
-     */
-    public boolean unequal(final Dfp x) {
-        if (isNaN() || x.isNaN() || field.getRadixDigits() != x.field.getRadixDigits()) {
-            return false;
-        }
-
-        return greaterThan(x) || lessThan(x);
-    }
-
-    /** Compare two instances.
-     * @param a first instance in comparison
-     * @param b second instance in comparison
-     * @return -1 if a<b, 1 if a>b and 0 if a==b
-     *  Note this method does not properly handle NaNs or numbers with different precision.
-     */
-    private static int compare(final Dfp a, final Dfp b) {
-        // Ignore the sign of zero
-        if (a.mant[a.mant.length - 1] == 0 && b.mant[b.mant.length - 1] == 0 &&
-            a.nans == FINITE && b.nans == FINITE) {
-            return 0;
-        }
-
-        if (a.sign != b.sign) {
-            if (a.sign == -1) {
-                return -1;
-            } else {
-                return 1;
-            }
-        }
-
-        // deal with the infinities
-        if (a.nans == INFINITE && b.nans == FINITE) {
-            return a.sign;
-        }
-
-        if (a.nans == FINITE && b.nans == INFINITE) {
-            return -b.sign;
-        }
-
-        if (a.nans == INFINITE && b.nans == INFINITE) {
-            return 0;
-        }
-
-        // Handle special case when a or b is zero, by ignoring the exponents
-        if (b.mant[b.mant.length-1] != 0 && a.mant[b.mant.length-1] != 0) {
-            if (a.exp < b.exp) {
-                return -a.sign;
-            }
-
-            if (a.exp > b.exp) {
-                return a.sign;
-            }
-        }
-
-        // compare the mantissas
-        for (int i = a.mant.length - 1; i >= 0; i--) {
-            if (a.mant[i] > b.mant[i]) {
-                return a.sign;
-            }
-
-            if (a.mant[i] < b.mant[i]) {
-                return -a.sign;
-            }
-        }
-
-        return 0;
-
-    }
-
-    /** Round to nearest integer using the round-half-even method.
-     *  That is round to nearest integer unless both are equidistant.
-     *  In which case round to the even one.
-     *  @return rounded value
-     * @since 3.2
-     */
-    public Dfp rint() {
-        return trunc(DfpField.RoundingMode.ROUND_HALF_EVEN);
-    }
-
-    /** Round to an integer using the round floor mode.
-     * That is, round toward -Infinity
-     *  @return rounded value
-     * @since 3.2
-     */
-    public Dfp floor() {
-        return trunc(DfpField.RoundingMode.ROUND_FLOOR);
-    }
-
-    /** Round to an integer using the round ceil mode.
-     * That is, round toward +Infinity
-     *  @return rounded value
-     * @since 3.2
-     */
-    public Dfp ceil() {
-        return trunc(DfpField.RoundingMode.ROUND_CEIL);
-    }
-
-    /** Returns the IEEE remainder.
-     * @param d divisor
-     * @return this less n &times; d, where n is the integer closest to this/d
-     * @since 3.2
-     */
-    public Dfp remainder(final Dfp d) {
-
-        final Dfp result = this.subtract(this.divide(d).rint().multiply(d));
-
-        // IEEE 854-1987 says that if the result is zero, then it carries the sign of this
-        if (result.mant[mant.length-1] == 0) {
-            result.sign = sign;
-        }
-
-        return result;
-
-    }
-
-    /** Does the integer conversions with the specified rounding.
-     * @param rmode rounding mode to use
-     * @return truncated value
-     */
-    protected Dfp trunc(final DfpField.RoundingMode rmode) {
-        boolean changed = false;
-
-        if (isNaN()) {
-            return newInstance(this);
-        }
-
-        if (nans == INFINITE) {
-            return newInstance(this);
-        }
-
-        if (mant[mant.length-1] == 0) {
-            // a is zero
-            return newInstance(this);
-        }
-
-        /* If the exponent is less than zero then we can certainly
-         * return zero */
-        if (exp < 0) {
-            field.setIEEEFlagsBits(DfpField.FLAG_INEXACT);
-            Dfp result = newInstance(getZero());
-            result = dotrap(DfpField.FLAG_INEXACT, TRUNC_TRAP, this, result);
-            return result;
-        }
-
-        /* If the exponent is greater than or equal to digits, then it
-         * must already be an integer since there is no precision left
-         * for any fractional part */
-
-        if (exp >= mant.length) {
-            return newInstance(this);
-        }
-
-        /* General case:  create another dfp, result, that contains the
-         * a with the fractional part lopped off.  */
-
-        Dfp result = newInstance(this);
-        for (int i = 0; i < mant.length-result.exp; i++) {
-            changed |= result.mant[i] != 0;
-            result.mant[i] = 0;
-        }
-
-        if (changed) {
-            switch (rmode) {
-                case ROUND_FLOOR:
-                    if (result.sign == -1) {
-                        // then we must increment the mantissa by one
-                        result = result.add(newInstance(-1));
-                    }
-                    break;
-
-                case ROUND_CEIL:
-                    if (result.sign == 1) {
-                        // then we must increment the mantissa by one
-                        result = result.add(getOne());
-                    }
-                    break;
-
-                case ROUND_HALF_EVEN:
-                default:
-                    final Dfp half = newInstance("0.5");
-                    Dfp a = subtract(result);  // difference between this and result
-                    a.sign = 1;            // force positive (take abs)
-                    if (a.greaterThan(half)) {
-                        a = newInstance(getOne());
-                        a.sign = sign;
-                        result = result.add(a);
-                    }
-
-                    /** If exactly equal to 1/2 and odd then increment */
-                    if (a.equals(half) && result.exp > 0 && (result.mant[mant.length-result.exp]&1) != 0) {
-                        a = newInstance(getOne());
-                        a.sign = sign;
-                        result = result.add(a);
-                    }
-                    break;
-            }
-
-            field.setIEEEFlagsBits(DfpField.FLAG_INEXACT);  // signal inexact
-            result = dotrap(DfpField.FLAG_INEXACT, TRUNC_TRAP, this, result);
-            return result;
-        }
-
-        return result;
-    }
-
-    /** Convert this to an integer.
-     * If greater than 2147483647, it returns 2147483647. If less than -2147483648 it returns -2147483648.
-     * @return converted number
-     */
-    public int intValue() {
-        Dfp rounded;
-        int result = 0;
-
-        rounded = rint();
-
-        if (rounded.greaterThan(newInstance(2147483647))) {
-            return 2147483647;
-        }
-
-        if (rounded.lessThan(newInstance(-2147483648))) {
-            return -2147483648;
-        }
-
-        for (int i = mant.length - 1; i >= mant.length - rounded.exp; i--) {
-            result = result * RADIX + rounded.mant[i];
-        }
-
-        if (rounded.sign == -1) {
-            result = -result;
-        }
-
-        return result;
-    }
-
-    /** Get the exponent of the greatest power of 10000 that is
-     *  less than or equal to the absolute value of this.  I.E.  if
-     *  this is 10<sup>6</sup> then log10K would return 1.
-     *  @return integer base 10000 logarithm
-     */
-    public int log10K() {
-        return exp - 1;
-    }
-
-    /** Get the specified  power of 10000.
-     * @param e desired power
-     * @return 10000<sup>e</sup>
-     */
-    public Dfp power10K(final int e) {
-        Dfp d = newInstance(getOne());
-        d.exp = e + 1;
-        return d;
-    }
-
-    /** Get the exponent of the greatest power of 10 that is less than or equal to abs(this).
-     *  @return integer base 10 logarithm
-     * @since 3.2
-     */
-    public int intLog10()  {
-        if (mant[mant.length-1] > 1000) {
-            return exp * 4 - 1;
-        }
-        if (mant[mant.length-1] > 100) {
-            return exp * 4 - 2;
-        }
-        if (mant[mant.length-1] > 10) {
-            return exp * 4 - 3;
-        }
-        return exp * 4 - 4;
-    }
-
-    /** Return the specified  power of 10.
-     * @param e desired power
-     * @return 10<sup>e</sup>
-     */
-    public Dfp power10(final int e) {
-        Dfp d = newInstance(getOne());
-
-        if (e >= 0) {
-            d.exp = e / 4 + 1;
-        } else {
-            d.exp = (e + 1) / 4;
-        }
-
-        switch ((e % 4 + 4) % 4) {
-            case 0:
-                break;
-            case 1:
-                d = d.multiply(10);
-                break;
-            case 2:
-                d = d.multiply(100);
-                break;
-            default:
-                d = d.multiply(1000);
-        }
-
-        return d;
-    }
-
-    /** Negate the mantissa of this by computing the complement.
-     *  Leaves the sign bit unchanged, used internally by add.
-     *  Denormalized numbers are handled properly here.
-     *  @param extra ???
-     *  @return ???
-     */
-    protected int complement(int extra) {
-
-        extra = RADIX-extra;
-        for (int i = 0; i < mant.length; i++) {
-            mant[i] = RADIX-mant[i]-1;
-        }
-
-        int rh = extra / RADIX;
-        extra -= rh * RADIX;
-        for (int i = 0; i < mant.length; i++) {
-            final int r = mant[i] + rh;
-            rh = r / RADIX;
-            mant[i] = r - rh * RADIX;
-        }
-
-        return extra;
-    }
-
-    /** Add x to this.
-     * @param x number to add
-     * @return sum of this and x
-     */
-    public Dfp add(final Dfp x) {
-
-        // make sure we don't mix number with different precision
-        if (field.getRadixDigits() != x.field.getRadixDigits()) {
-            field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-            final Dfp result = newInstance(getZero());
-            result.nans = QNAN;
-            return dotrap(DfpField.FLAG_INVALID, ADD_TRAP, x, result);
-        }
-
-        /* handle special cases */
-        if (nans != FINITE || x.nans != FINITE) {
-            if (isNaN()) {
-                return this;
-            }
-
-            if (x.isNaN()) {
-                return x;
-            }
-
-            if (nans == INFINITE && x.nans == FINITE) {
-                return this;
-            }
-
-            if (x.nans == INFINITE && nans == FINITE) {
-                return x;
-            }
-
-            if (x.nans == INFINITE && nans == INFINITE && sign == x.sign) {
-                return x;
-            }
-
-            if (x.nans == INFINITE && nans == INFINITE && sign != x.sign) {
-                field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-                Dfp result = newInstance(getZero());
-                result.nans = QNAN;
-                result = dotrap(DfpField.FLAG_INVALID, ADD_TRAP, x, result);
-                return result;
-            }
-        }
-
-        /* copy this and the arg */
-        Dfp a = newInstance(this);
-        Dfp b = newInstance(x);
-
-        /* initialize the result object */
-        Dfp result = newInstance(getZero());
-
-        /* Make all numbers positive, but remember their sign */
-        final byte asign = a.sign;
-        final byte bsign = b.sign;
-
-        a.sign = 1;
-        b.sign = 1;
-
-        /* The result will be signed like the arg with greatest magnitude */
-        byte rsign = bsign;
-        if (compare(a, b) > 0) {
-            rsign = asign;
-        }
-
-        /* Handle special case when a or b is zero, by setting the exponent
-       of the zero number equal to the other one.  This avoids an alignment
-       which would cause catastropic loss of precision */
-        if (b.mant[mant.length-1] == 0) {
-            b.exp = a.exp;
-        }
-
-        if (a.mant[mant.length-1] == 0) {
-            a.exp = b.exp;
-        }
-
-        /* align number with the smaller exponent */
-        int aextradigit = 0;
-        int bextradigit = 0;
-        if (a.exp < b.exp) {
-            aextradigit = a.align(b.exp);
-        } else {
-            bextradigit = b.align(a.exp);
-        }
-
-        /* complement the smaller of the two if the signs are different */
-        if (asign != bsign) {
-            if (asign == rsign) {
-                bextradigit = b.complement(bextradigit);
-            } else {
-                aextradigit = a.complement(aextradigit);
-            }
-        }
-
-        /* add the mantissas */
-        int rh = 0; /* acts as a carry */
-        for (int i = 0; i < mant.length; i++) {
-            final int r = a.mant[i]+b.mant[i]+rh;
-            rh = r / RADIX;
-            result.mant[i] = r - rh * RADIX;
-        }
-        result.exp = a.exp;
-        result.sign = rsign;
-
-        /* handle overflow -- note, when asign!=bsign an overflow is
-         * normal and should be ignored.  */
-
-        if (rh != 0 && (asign == bsign)) {
-            final int lostdigit = result.mant[0];
-            result.shiftRight();
-            result.mant[mant.length-1] = rh;
-            final int excp = result.round(lostdigit);
-            if (excp != 0) {
-                result = dotrap(excp, ADD_TRAP, x, result);
-            }
-        }
-
-        /* normalize the result */
-        for (int i = 0; i < mant.length; i++) {
-            if (result.mant[mant.length-1] != 0) {
-                break;
-            }
-            result.shiftLeft();
-            if (i == 0) {
-                result.mant[0] = aextradigit+bextradigit;
-                aextradigit = 0;
-                bextradigit = 0;
-            }
-        }
-
-        /* result is zero if after normalization the most sig. digit is zero */
-        if (result.mant[mant.length-1] == 0) {
-            result.exp = 0;
-
-            if (asign != bsign) {
-                // Unless adding 2 negative zeros, sign is positive
-                result.sign = 1;  // Per IEEE 854-1987 Section 6.3
-            }
-        }
-
-        /* Call round to test for over/under flows */
-        final int excp = result.round(aextradigit + bextradigit);
-        if (excp != 0) {
-            result = dotrap(excp, ADD_TRAP, x, result);
-        }
-
-        return result;
-    }
-
-    /** Returns a number that is this number with the sign bit reversed.
-     * @return the opposite of this
-     */
-    public Dfp negate() {
-        Dfp result = newInstance(this);
-        result.sign = (byte) - result.sign;
-        return result;
-    }
-
-    /** Subtract x from this.
-     * @param x number to subtract
-     * @return difference of this and a
-     */
-    public Dfp subtract(final Dfp x) {
-        return add(x.negate());
-    }
-
-    /** Round this given the next digit n using the current rounding mode.
-     * @param n ???
-     * @return the IEEE flag if an exception occurred
-     */
-    protected int round(int n) {
-        boolean inc = false;
-        switch (field.getRoundingMode()) {
-            case ROUND_DOWN:
-                inc = false;
-                break;
-
-            case ROUND_UP:
-                inc = n != 0;       // round up if n!=0
-                break;
-
-            case ROUND_HALF_UP:
-                inc = n >= 5000;  // round half up
-                break;
-
-            case ROUND_HALF_DOWN:
-                inc = n > 5000;  // round half down
-                break;
-
-            case ROUND_HALF_EVEN:
-                inc = n > 5000 || (n == 5000 && (mant[0] & 1) == 1);  // round half-even
-                break;
-
-            case ROUND_HALF_ODD:
-                inc = n > 5000 || (n == 5000 && (mant[0] & 1) == 0);  // round half-odd
-                break;
-
-            case ROUND_CEIL:
-                inc = sign == 1 && n != 0;  // round ceil
-                break;
-
-            case ROUND_FLOOR:
-            default:
-                inc = sign == -1 && n != 0;  // round floor
-                break;
-        }
-
-        if (inc) {
-            // increment if necessary
-            int rh = 1;
-            for (int i = 0; i < mant.length; i++) {
-                final int r = mant[i] + rh;
-                rh = r / RADIX;
-                mant[i] = r - rh * RADIX;
-            }
-
-            if (rh != 0) {
-                shiftRight();
-                mant[mant.length-1] = rh;
-            }
-        }
-
-        // check for exceptional cases and raise signals if necessary
-        if (exp < MIN_EXP) {
-            // Gradual Underflow
-            field.setIEEEFlagsBits(DfpField.FLAG_UNDERFLOW);
-            return DfpField.FLAG_UNDERFLOW;
-        }
-
-        if (exp > MAX_EXP) {
-            // Overflow
-            field.setIEEEFlagsBits(DfpField.FLAG_OVERFLOW);
-            return DfpField.FLAG_OVERFLOW;
-        }
-
-        if (n != 0) {
-            // Inexact
-            field.setIEEEFlagsBits(DfpField.FLAG_INEXACT);
-            return DfpField.FLAG_INEXACT;
-        }
-
-        return 0;
-
-    }
-
-    /** Multiply this by x.
-     * @param x multiplicand
-     * @return product of this and x
-     */
-    public Dfp multiply(final Dfp x) {
-
-        // make sure we don't mix number with different precision
-        if (field.getRadixDigits() != x.field.getRadixDigits()) {
-            field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-            final Dfp result = newInstance(getZero());
-            result.nans = QNAN;
-            return dotrap(DfpField.FLAG_INVALID, MULTIPLY_TRAP, x, result);
-        }
-
-        Dfp result = newInstance(getZero());
-
-        /* handle special cases */
-        if (nans != FINITE || x.nans != FINITE) {
-            if (isNaN()) {
-                return this;
-            }
-
-            if (x.isNaN()) {
-                return x;
-            }
-
-            if (nans == INFINITE && x.nans == FINITE && x.mant[mant.length-1] != 0) {
-                result = newInstance(this);
-                result.sign = (byte) (sign * x.sign);
-                return result;
-            }
-
-            if (x.nans == INFINITE && nans == FINITE && mant[mant.length-1] != 0) {
-                result = newInstance(x);
-                result.sign = (byte) (sign * x.sign);
-                return result;
-            }
-
-            if (x.nans == INFINITE && nans == INFINITE) {
-                result = newInstance(this);
-                result.sign = (byte) (sign * x.sign);
-                return result;
-            }
-
-            if ( (x.nans == INFINITE && nans == FINITE && mant[mant.length-1] == 0) ||
-                    (nans == INFINITE && x.nans == FINITE && x.mant[mant.length-1] == 0) ) {
-                field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-                result = newInstance(getZero());
-                result.nans = QNAN;
-                result = dotrap(DfpField.FLAG_INVALID, MULTIPLY_TRAP, x, result);
-                return result;
-            }
-        }
-
-        int[] product = new int[mant.length*2];  // Big enough to hold even the largest result
-
-        for (int i = 0; i < mant.length; i++) {
-            int rh = 0;  // acts as a carry
-            for (int j=0; j<mant.length; j++) {
-                int r = mant[i] * x.mant[j];    // multiply the 2 digits
-                r += product[i+j] + rh;  // add to the product digit with carry in
-
-                rh = r / RADIX;
-                product[i+j] = r - rh * RADIX;
-            }
-            product[i+mant.length] = rh;
-        }
-
-        // Find the most sig digit
-        int md = mant.length * 2 - 1;  // default, in case result is zero
-        for (int i = mant.length * 2 - 1; i >= 0; i--) {
-            if (product[i] != 0) {
-                md = i;
-                break;
-            }
-        }
-
-        // Copy the digits into the result
-        for (int i = 0; i < mant.length; i++) {
-            result.mant[mant.length - i - 1] = product[md - i];
-        }
-
-        // Fixup the exponent.
-        result.exp = exp + x.exp + md - 2 * mant.length + 1;
-        result.sign = (byte)((sign == x.sign)?1:-1);
-
-        if (result.mant[mant.length-1] == 0) {
-            // if result is zero, set exp to zero
-            result.exp = 0;
-        }
-
-        final int excp;
-        if (md > (mant.length-1)) {
-            excp = result.round(product[md-mant.length]);
-        } else {
-            excp = result.round(0); // has no effect except to check status
-        }
-
-        if (excp != 0) {
-            result = dotrap(excp, MULTIPLY_TRAP, x, result);
-        }
-
-        return result;
-
-    }
-
-    /** Multiply this by a single digit x.
-     * @param x multiplicand
-     * @return product of this and x
-     */
-    public Dfp multiply(final int x) {
-        if (x >= 0 && x < RADIX) {
-            return multiplyFast(x);
-        } else {
-            return multiply(newInstance(x));
-        }
-    }
-
-    /** Multiply this by a single digit 0&lt;=x&lt;radix.
-     * There are speed advantages in this special case.
-     * @param x multiplicand
-     * @return product of this and x
-     */
-    private Dfp multiplyFast(final int x) {
-        Dfp result = newInstance(this);
-
-        /* handle special cases */
-        if (nans != FINITE) {
-            if (isNaN()) {
-                return this;
-            }
-
-            if (nans == INFINITE && x != 0) {
-                result = newInstance(this);
-                return result;
-            }
-
-            if (nans == INFINITE && x == 0) {
-                field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-                result = newInstance(getZero());
-                result.nans = QNAN;
-                result = dotrap(DfpField.FLAG_INVALID, MULTIPLY_TRAP, newInstance(getZero()), result);
-                return result;
-            }
-        }
-
-        /* range check x */
-        if (x < 0 || x >= RADIX) {
-            field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-            result = newInstance(getZero());
-            result.nans = QNAN;
-            result = dotrap(DfpField.FLAG_INVALID, MULTIPLY_TRAP, result, result);
-            return result;
-        }
-
-        int rh = 0;
-        for (int i = 0; i < mant.length; i++) {
-            final int r = mant[i] * x + rh;
-            rh = r / RADIX;
-            result.mant[i] = r - rh * RADIX;
-        }
-
-        int lostdigit = 0;
-        if (rh != 0) {
-            lostdigit = result.mant[0];
-            result.shiftRight();
-            result.mant[mant.length-1] = rh;
-        }
-
-        if (result.mant[mant.length-1] == 0) { // if result is zero, set exp to zero
-            result.exp = 0;
-        }
-
-        final int excp = result.round(lostdigit);
-        if (excp != 0) {
-            result = dotrap(excp, MULTIPLY_TRAP, result, result);
-        }
-
-        return result;
-    }
-
-    /** Divide this by divisor.
-     * @param divisor divisor
-     * @return quotient of this by divisor
-     */
-    public Dfp divide(Dfp divisor) {
-        int dividend[]; // current status of the dividend
-        int quotient[]; // quotient
-        int remainder[];// remainder
-        int qd;         // current quotient digit we're working with
-        int nsqd;       // number of significant quotient digits we have
-        int trial=0;    // trial quotient digit
-        int minadj;     // minimum adjustment
-        boolean trialgood; // Flag to indicate a good trail digit
-        int md=0;       // most sig digit in result
-        int excp;       // exceptions
-
-        // make sure we don't mix number with different precision
-        if (field.getRadixDigits() != divisor.field.getRadixDigits()) {
-            field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-            final Dfp result = newInstance(getZero());
-            result.nans = QNAN;
-            return dotrap(DfpField.FLAG_INVALID, DIVIDE_TRAP, divisor, result);
-        }
-
-        Dfp result = newInstance(getZero());
-
-        /* handle special cases */
-        if (nans != FINITE || divisor.nans != FINITE) {
-            if (isNaN()) {
-                return this;
-            }
-
-            if (divisor.isNaN()) {
-                return divisor;
-            }
-
-            if (nans == INFINITE && divisor.nans == FINITE) {
-                result = newInstance(this);
-                result.sign = (byte) (sign * divisor.sign);
-                return result;
-            }
-
-            if (divisor.nans == INFINITE && nans == FINITE) {
-                result = newInstance(getZero());
-                result.sign = (byte) (sign * divisor.sign);
-                return result;
-            }
-
-            if (divisor.nans == INFINITE && nans == INFINITE) {
-                field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-                result = newInstance(getZero());
-                result.nans = QNAN;
-                result = dotrap(DfpField.FLAG_INVALID, DIVIDE_TRAP, divisor, result);
-                return result;
-            }
-        }
-
-        /* Test for divide by zero */
-        if (divisor.mant[mant.length-1] == 0) {
-            field.setIEEEFlagsBits(DfpField.FLAG_DIV_ZERO);
-            result = newInstance(getZero());
-            result.sign = (byte) (sign * divisor.sign);
-            result.nans = INFINITE;
-            result = dotrap(DfpField.FLAG_DIV_ZERO, DIVIDE_TRAP, divisor, result);
-            return result;
-        }
-
-        dividend = new int[mant.length+1];  // one extra digit needed
-        quotient = new int[mant.length+2];  // two extra digits needed 1 for overflow, 1 for rounding
-        remainder = new int[mant.length+1]; // one extra digit needed
-
-        /* Initialize our most significant digits to zero */
-
-        dividend[mant.length] = 0;
-        quotient[mant.length] = 0;
-        quotient[mant.length+1] = 0;
-        remainder[mant.length] = 0;
-
-        /* copy our mantissa into the dividend, initialize the
-       quotient while we are at it */
-
-        for (int i = 0; i < mant.length; i++) {
-            dividend[i] = mant[i];
-            quotient[i] = 0;
-            remainder[i] = 0;
-        }
-
-        /* outer loop.  Once per quotient digit */
-        nsqd = 0;
-        for (qd = mant.length+1; qd >= 0; qd--) {
-            /* Determine outer limits of our quotient digit */
-
-            // r =  most sig 2 digits of dividend
-            final int divMsb = dividend[mant.length]*RADIX+dividend[mant.length-1];
-            int min = divMsb       / (divisor.mant[mant.length-1]+1);
-            int max = (divMsb + 1) / divisor.mant[mant.length-1];
-
-            trialgood = false;
-            while (!trialgood) {
-                // try the mean
-                trial = (min+max)/2;
-
-                /* Multiply by divisor and store as remainder */
-                int rh = 0;
-                for (int i = 0; i < mant.length + 1; i++) {
-                    int dm = (i<mant.length)?divisor.mant[i]:0;
-                    final int r = (dm * trial) + rh;
-                    rh = r / RADIX;
-                    remainder[i] = r - rh * RADIX;
-                }
-
-                /* subtract the remainder from the dividend */
-                rh = 1;  // carry in to aid the subtraction
-                for (int i = 0; i < mant.length + 1; i++) {
-                    final int r = ((RADIX-1) - remainder[i]) + dividend[i] + rh;
-                    rh = r / RADIX;
-                    remainder[i] = r - rh * RADIX;
-                }
-
-                /* Lets analyze what we have here */
-                if (rh == 0) {
-                    // trial is too big -- negative remainder
-                    max = trial-1;
-                    continue;
-                }
-
-                /* find out how far off the remainder is telling us we are */
-                minadj = (remainder[mant.length] * RADIX)+remainder[mant.length-1];
-                minadj /= divisor.mant[mant.length-1] + 1;
-
-                if (minadj >= 2) {
-                    min = trial+minadj;  // update the minimum
-                    continue;
-                }
-
-                /* May have a good one here, check more thoroughly.  Basically
-           its a good one if it is less than the divisor */
-                trialgood = false;  // assume false
-                for (int i = mant.length - 1; i >= 0; i--) {
-                    if (divisor.mant[i] > remainder[i]) {
-                        trialgood = true;
-                    }
-                    if (divisor.mant[i] < remainder[i]) {
-                        break;
-                    }
-                }
-
-                if (remainder[mant.length] != 0) {
-                    trialgood = false;
-                }
-
-                if (trialgood == false) {
-                    min = trial+1;
-                }
-            }
-
-            /* Great we have a digit! */
-            quotient[qd] = trial;
-            if (trial != 0 || nsqd != 0) {
-                nsqd++;
-            }
-
-            if (field.getRoundingMode() == DfpField.RoundingMode.ROUND_DOWN && nsqd == mant.length) {
-                // We have enough for this mode
-                break;
-            }
-
-            if (nsqd > mant.length) {
-                // We have enough digits
-                break;
-            }
-
-            /* move the remainder into the dividend while left shifting */
-            dividend[0] = 0;
-            for (int i = 0; i < mant.length; i++) {
-                dividend[i + 1] = remainder[i];
-            }
-        }
-
-        /* Find the most sig digit */
-        md = mant.length;  // default
-        for (int i = mant.length + 1; i >= 0; i--) {
-            if (quotient[i] != 0) {
-                md = i;
-                break;
-            }
-        }
-
-        /* Copy the digits into the result */
-        for (int i=0; i<mant.length; i++) {
-            result.mant[mant.length-i-1] = quotient[md-i];
-        }
-
-        /* Fixup the exponent. */
-        result.exp = exp - divisor.exp + md - mant.length;
-        result.sign = (byte) ((sign == divisor.sign) ? 1 : -1);
-
-        if (result.mant[mant.length-1] == 0) { // if result is zero, set exp to zero
-            result.exp = 0;
-        }
-
-        if (md > (mant.length-1)) {
-            excp = result.round(quotient[md-mant.length]);
-        } else {
-            excp = result.round(0);
-        }
-
-        if (excp != 0) {
-            result = dotrap(excp, DIVIDE_TRAP, divisor, result);
-        }
-
-        return result;
-    }
-
-    /** Divide by a single digit less than radix.
-     *  Special case, so there are speed advantages. 0 &lt;= divisor &lt; radix
-     * @param divisor divisor
-     * @return quotient of this by divisor
-     */
-    public Dfp divide(int divisor) {
-
-        // Handle special cases
-        if (nans != FINITE) {
-            if (isNaN()) {
-                return this;
-            }
-
-            if (nans == INFINITE) {
-                return newInstance(this);
-            }
-        }
-
-        // Test for divide by zero
-        if (divisor == 0) {
-            field.setIEEEFlagsBits(DfpField.FLAG_DIV_ZERO);
-            Dfp result = newInstance(getZero());
-            result.sign = sign;
-            result.nans = INFINITE;
-            result = dotrap(DfpField.FLAG_DIV_ZERO, DIVIDE_TRAP, getZero(), result);
-            return result;
-        }
-
-        // range check divisor
-        if (divisor < 0 || divisor >= RADIX) {
-            field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-            Dfp result = newInstance(getZero());
-            result.nans = QNAN;
-            result = dotrap(DfpField.FLAG_INVALID, DIVIDE_TRAP, result, result);
-            return result;
-        }
-
-        Dfp result = newInstance(this);
-
-        int rl = 0;
-        for (int i = mant.length-1; i >= 0; i--) {
-            final int r = rl*RADIX + result.mant[i];
-            final int rh = r / divisor;
-            rl = r - rh * divisor;
-            result.mant[i] = rh;
-        }
-
-        if (result.mant[mant.length-1] == 0) {
-            // normalize
-            result.shiftLeft();
-            final int r = rl * RADIX;        // compute the next digit and put it in
-            final int rh = r / divisor;
-            rl = r - rh * divisor;
-            result.mant[0] = rh;
-        }
-
-        final int excp = result.round(rl * RADIX / divisor);  // do the rounding
-        if (excp != 0) {
-            result = dotrap(excp, DIVIDE_TRAP, result, result);
-        }
-
-        return result;
-
-    }
-
-    /** {@inheritDoc} */
-    public Dfp reciprocal() {
-        return field.getOne().divide(this);
-    }
-
-    /** Compute the square root.
-     * @return square root of the instance
-     * @since 3.2
-     */
-    public Dfp sqrt() {
-
-        // check for unusual cases
-        if (nans == FINITE && mant[mant.length-1] == 0) {
-            // if zero
-            return newInstance(this);
-        }
-
-        if (nans != FINITE) {
-            if (nans == INFINITE && sign == 1) {
-                // if positive infinity
-                return newInstance(this);
-            }
-
-            if (nans == QNAN) {
-                return newInstance(this);
-            }
-
-            if (nans == SNAN) {
-                Dfp result;
-
-                field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-                result = newInstance(this);
-                result = dotrap(DfpField.FLAG_INVALID, SQRT_TRAP, null, result);
-                return result;
-            }
-        }
-
-        if (sign == -1) {
-            // if negative
-            Dfp result;
-
-            field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-            result = newInstance(this);
-            result.nans = QNAN;
-            result = dotrap(DfpField.FLAG_INVALID, SQRT_TRAP, null, result);
-            return result;
-        }
-
-        Dfp x = newInstance(this);
-
-        /* Lets make a reasonable guess as to the size of the square root */
-        if (x.exp < -1 || x.exp > 1) {
-            x.exp = this.exp / 2;
-        }
-
-        /* Coarsely estimate the mantissa */
-        switch (x.mant[mant.length-1] / 2000) {
-            case 0:
-                x.mant[mant.length-1] = x.mant[mant.length-1]/2+1;
-                break;
-            case 2:
-                x.mant[mant.length-1] = 1500;
-                break;
-            case 3:
-                x.mant[mant.length-1] = 2200;
-                break;
-            default:
-                x.mant[mant.length-1] = 3000;
-        }
-
-        Dfp dx = newInstance(x);
-
-        /* Now that we have the first pass estimate, compute the rest
-       by the formula dx = (y - x*x) / (2x); */
-
-        Dfp px  = getZero();
-        Dfp ppx = getZero();
-        while (x.unequal(px)) {
-            dx = newInstance(x);
-            dx.sign = -1;
-            dx = dx.add(this.divide(x));
-            dx = dx.divide(2);
-            ppx = px;
-            px = x;
-            x = x.add(dx);
-
-            if (x.equals(ppx)) {
-                // alternating between two values
-                break;
-            }
-
-            // if dx is zero, break.  Note testing the most sig digit
-            // is a sufficient test since dx is normalized
-            if (dx.mant[mant.length-1] == 0) {
-                break;
-            }
-        }
-
-        return x;
-
-    }
-
-    /** Get a string representation of the instance.
-     * @return string representation of the instance
-     */
-    @Override
-    public String toString() {
-        if (nans != FINITE) {
-            // if non-finite exceptional cases
-            if (nans == INFINITE) {
-                return (sign < 0) ? NEG_INFINITY_STRING : POS_INFINITY_STRING;
-            } else {
-                return NAN_STRING;
-            }
-        }
-
-        if (exp > mant.length || exp < -1) {
-            return dfp2sci();
-        }
-
-        return dfp2string();
-
-    }
-
-    /** Convert an instance to a string using scientific notation.
-     * @return string representation of the instance in scientific notation
-     */
-    protected String dfp2sci() {
-        char rawdigits[]    = new char[mant.length * 4];
-        char outputbuffer[] = new char[mant.length * 4 + 20];
-        int p;
-        int q;
-        int e;
-        int ae;
-        int shf;
-
-        // Get all the digits
-        p = 0;
-        for (int i = mant.length - 1; i >= 0; i--) {
-            rawdigits[p++] = (char) ((mant[i] / 1000) + '0');
-            rawdigits[p++] = (char) (((mant[i] / 100) %10) + '0');
-            rawdigits[p++] = (char) (((mant[i] / 10) % 10) + '0');
-            rawdigits[p++] = (char) (((mant[i]) % 10) + '0');
-        }
-
-        // Find the first non-zero one
-        for (p = 0; p < rawdigits.length; p++) {
-            if (rawdigits[p] != '0') {
-                break;
-            }
-        }
-        shf = p;
-
-        // Now do the conversion
-        q = 0;
-        if (sign == -1) {
-            outputbuffer[q++] = '-';
-        }
-
-        if (p != rawdigits.length) {
-            // there are non zero digits...
-            outputbuffer[q++] = rawdigits[p++];
-            outputbuffer[q++] = '.';
-
-            while (p<rawdigits.length) {
-                outputbuffer[q++] = rawdigits[p++];
-            }
-        } else {
-            outputbuffer[q++] = '0';
-            outputbuffer[q++] = '.';
-            outputbuffer[q++] = '0';
-            outputbuffer[q++] = 'e';
-            outputbuffer[q++] = '0';
-            return new String(outputbuffer, 0, 5);
-        }
-
-        outputbuffer[q++] = 'e';
-
-        // Find the msd of the exponent
-
-        e = exp * 4 - shf - 1;
-        ae = e;
-        if (e < 0) {
-            ae = -e;
-        }
-
-        // Find the largest p such that p < e
-        for (p = 1000000000; p > ae; p /= 10) {
-            // nothing to do
-        }
-
-        if (e < 0) {
-            outputbuffer[q++] = '-';
-        }
-
-        while (p > 0) {
-            outputbuffer[q++] = (char)(ae / p + '0');
-            ae %= p;
-            p /= 10;
-        }
-
-        return new String(outputbuffer, 0, q);
-
-    }
-
-    /** Convert an instance to a string using normal notation.
-     * @return string representation of the instance in normal notation
-     */
-    protected String dfp2string() {
-        char buffer[] = new char[mant.length*4 + 20];
-        int p = 1;
-        int q;
-        int e = exp;
-        boolean pointInserted = false;
-
-        buffer[0] = ' ';
-
-        if (e <= 0) {
-            buffer[p++] = '0';
-            buffer[p++] = '.';
-            pointInserted = true;
-        }
-
-        while (e < 0) {
-            buffer[p++] = '0';
-            buffer[p++] = '0';
-            buffer[p++] = '0';
-            buffer[p++] = '0';
-            e++;
-        }
-
-        for (int i = mant.length - 1; i >= 0; i--) {
-            buffer[p++] = (char) ((mant[i] / 1000) + '0');
-            buffer[p++] = (char) (((mant[i] / 100) % 10) + '0');
-            buffer[p++] = (char) (((mant[i] / 10) % 10) + '0');
-            buffer[p++] = (char) (((mant[i]) % 10) + '0');
-            if (--e == 0) {
-                buffer[p++] = '.';
-                pointInserted = true;
-            }
-        }
-
-        while (e > 0) {
-            buffer[p++] = '0';
-            buffer[p++] = '0';
-            buffer[p++] = '0';
-            buffer[p++] = '0';
-            e--;
-        }
-
-        if (!pointInserted) {
-            // Ensure we have a radix point!
-            buffer[p++] = '.';
-        }
-
-        // Suppress leading zeros
-        q = 1;
-        while (buffer[q] == '0') {
-            q++;
-        }
-        if (buffer[q] == '.') {
-            q--;
-        }
-
-        // Suppress trailing zeros
-        while (buffer[p-1] == '0') {
-            p--;
-        }
-
-        // Insert sign
-        if (sign < 0) {
-            buffer[--q] = '-';
-        }
-
-        return new String(buffer, q, p - q);
-
-    }
-
-    /** Raises a trap.  This does not set the corresponding flag however.
-     *  @param type the trap type
-     *  @param what - name of routine trap occurred in
-     *  @param oper - input operator to function
-     *  @param result - the result computed prior to the trap
-     *  @return The suggested return value from the trap handler
-     */
-    public Dfp dotrap(int type, String what, Dfp oper, Dfp result) {
-        Dfp def = result;
-
-        switch (type) {
-            case DfpField.FLAG_INVALID:
-                def = newInstance(getZero());
-                def.sign = result.sign;
-                def.nans = QNAN;
-                break;
-
-            case DfpField.FLAG_DIV_ZERO:
-                if (nans == FINITE && mant[mant.length-1] != 0) {
-                    // normal case, we are finite, non-zero
-                    def = newInstance(getZero());
-                    def.sign = (byte)(sign*oper.sign);
-                    def.nans = INFINITE;
-                }
-
-                if (nans == FINITE && mant[mant.length-1] == 0) {
-                    //  0/0
-                    def = newInstance(getZero());
-                    def.nans = QNAN;
-                }
-
-                if (nans == INFINITE || nans == QNAN) {
-                    def = newInstance(getZero());
-                    def.nans = QNAN;
-                }
-
-                if (nans == INFINITE || nans == SNAN) {
-                    def = newInstance(getZero());
-                    def.nans = QNAN;
-                }
-                break;
-
-            case DfpField.FLAG_UNDERFLOW:
-                if ( (result.exp+mant.length) < MIN_EXP) {
-                    def = newInstance(getZero());
-                    def.sign = result.sign;
-                } else {
-                    def = newInstance(result);  // gradual underflow
-                }
-                result.exp += ERR_SCALE;
-                break;
-
-            case DfpField.FLAG_OVERFLOW:
-                result.exp -= ERR_SCALE;
-                def = newInstance(getZero());
-                def.sign = result.sign;
-                def.nans = INFINITE;
-                break;
-
-            default: def = result; break;
-        }
-
-        return trap(type, what, oper, def, result);
-
-    }
-
-    /** Trap handler.  Subclasses may override this to provide trap
-     *  functionality per IEEE 854-1987.
-     *
-     *  @param type  The exception type - e.g. FLAG_OVERFLOW
-     *  @param what  The name of the routine we were in e.g. divide()
-     *  @param oper  An operand to this function if any
-     *  @param def   The default return value if trap not enabled
-     *  @param result    The result that is specified to be delivered per
-     *                   IEEE 854, if any
-     *  @return the value that should be return by the operation triggering the trap
-     */
-    protected Dfp trap(int type, String what, Dfp oper, Dfp def, Dfp result) {
-        return def;
-    }
-
-    /** Returns the type - one of FINITE, INFINITE, SNAN, QNAN.
-     * @return type of the number
-     */
-    public int classify() {
-        return nans;
-    }
-
-    /** Creates an instance that is the same as x except that it has the sign of y.
-     * abs(x) = dfp.copysign(x, dfp.one)
-     * @param x number to get the value from
-     * @param y number to get the sign from
-     * @return a number with the value of x and the sign of y
-     */
-    public static Dfp copysign(final Dfp x, final Dfp y) {
-        Dfp result = x.newInstance(x);
-        result.sign = y.sign;
-        return result;
-    }
-
-    /** Returns the next number greater than this one in the direction of x.
-     * If this==x then simply returns this.
-     * @param x direction where to look at
-     * @return closest number next to instance in the direction of x
-     */
-    public Dfp nextAfter(final Dfp x) {
-
-        // make sure we don't mix number with different precision
-        if (field.getRadixDigits() != x.field.getRadixDigits()) {
-            field.setIEEEFlagsBits(DfpField.FLAG_INVALID);
-            final Dfp result = newInstance(getZero());
-            result.nans = QNAN;
-            return dotrap(DfpField.FLAG_INVALID, NEXT_AFTER_TRAP, x, result);
-        }
-
-        // if this is greater than x
-        boolean up = false;
-        if (this.lessThan(x)) {
-            up = true;
-        }
-
-        if (compare(this, x) == 0) {
-            return newInstance(x);
-        }
-
-        if (lessThan(getZero())) {
-            up = !up;
-        }
-
-        final Dfp inc;
-        Dfp result;
-        if (up) {
-            inc = newInstance(getOne());
-            inc.exp = this.exp-mant.length+1;
-            inc.sign = this.sign;
-
-            if (this.equals(getZero())) {
-                inc.exp = MIN_EXP-mant.length;
-            }
-
-            result = add(inc);
-        } else {
-            inc = newInstance(getOne());
-            inc.exp = this.exp;
-            inc.sign = this.sign;
-
-            if (this.equals(inc)) {
-                inc.exp = this.exp-mant.length;
-            } else {
-                inc.exp = this.exp-mant.length+1;
-            }
-
-            if (this.equals(getZero())) {
-                inc.exp = MIN_EXP-mant.length;
-            }
-
-            result = this.subtract(inc);
-        }
-
-        if (result.classify() == INFINITE && this.classify() != INFINITE) {
-            field.setIEEEFlagsBits(DfpField.FLAG_INEXACT);
-            result = dotrap(DfpField.FLAG_INEXACT, NEXT_AFTER_TRAP, x, result);
-        }
-
-        if (result.equals(getZero()) && this.equals(getZero()) == false) {
-            field.setIEEEFlagsBits(DfpField.FLAG_INEXACT);
-            result = dotrap(DfpField.FLAG_INEXACT, NEXT_AFTER_TRAP, x, result);
-        }
-
-        return result;
-
-    }
-
-    /** Convert the instance into a double.
-     * @return a double approximating the instance
-     * @see #toSplitDouble()
-     */
-    public double toDouble() {
-
-        if (isInfinite()) {
-            if (lessThan(getZero())) {
-                return Double.NEGATIVE_INFINITY;
-            } else {
-                return Double.POSITIVE_INFINITY;
-            }
-        }
-
-        if (isNaN()) {
-            return Double.NaN;
-        }
-
-        Dfp y = this;
-        boolean negate = false;
-        int cmp0 = compare(this, getZero());
-        if (cmp0 == 0) {
-            return sign < 0 ? -0.0 : +0.0;
-        } else if (cmp0 < 0) {
-            y = negate();
-            negate = true;
-        }
-
-        /* Find the exponent, first estimate by integer log10, then adjust.
-         Should be faster than doing a natural logarithm.  */
-        int exponent = (int)(y.intLog10() * 3.32);
-        if (exponent < 0) {
-            exponent--;
-        }
-
-        Dfp tempDfp = DfpMath.pow(getTwo(), exponent);
-        while (tempDfp.lessThan(y) || tempDfp.equals(y)) {
-            tempDfp = tempDfp.multiply(2);
-            exponent++;
-        }
-        exponent--;
-
-        /* We have the exponent, now work on the mantissa */
-
-        y = y.divide(DfpMath.pow(getTwo(), exponent));
-        if (exponent > -1023) {
-            y = y.subtract(getOne());
-        }
-
-        if (exponent < -1074) {
-            return 0;
-        }
-
-        if (exponent > 1023) {
-            return negate ? Double.NEGATIVE_INFINITY : Double.POSITIVE_INFINITY;
-        }
-
-
-        y = y.multiply(newInstance(4503599627370496l)).rint();
-        String str = y.toString();
-        str = str.substring(0, str.length()-1);
-        long mantissa = Long.parseLong(str);
-
-        if (mantissa == 4503599627370496L) {
-            // Handle special case where we round up to next power of two
-            mantissa = 0;
-            exponent++;
-        }
-
-        /* Its going to be subnormal, so make adjustments */
-        if (exponent <= -1023) {
-            exponent--;
-        }
-
-        while (exponent < -1023) {
-            exponent++;
-            mantissa >>>= 1;
-        }
-
-        long bits = mantissa | ((exponent + 1023L) << 52);
-        double x = Double.longBitsToDouble(bits);
-
-        if (negate) {
-            x = -x;
-        }
-
-        return x;
-
-    }
-
-    /** Convert the instance into a split double.
-     * @return an array of two doubles which sum represent the instance
-     * @see #toDouble()
-     */
-    public double[] toSplitDouble() {
-        double split[] = new double[2];
-        long mask = 0xffffffffc0000000L;
-
-        split[0] = Double.longBitsToDouble(Double.doubleToLongBits(toDouble()) & mask);
-        split[1] = subtract(newInstance(split[0])).toDouble();
-
-        return split;
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public double getReal() {
-        return toDouble();
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp add(final double a) {
-        return add(newInstance(a));
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp subtract(final double a) {
-        return subtract(newInstance(a));
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp multiply(final double a) {
-        return multiply(newInstance(a));
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp divide(final double a) {
-        return divide(newInstance(a));
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp remainder(final double a) {
-        return remainder(newInstance(a));
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public long round() {
-        return FastMath.round(toDouble());
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp signum() {
-        if (isNaN() || isZero()) {
-            return this;
-        } else {
-            return newInstance(sign > 0 ? +1 : -1);
-        }
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp copySign(final Dfp s) {
-        if ((sign >= 0 && s.sign >= 0) || (sign < 0 && s.sign < 0)) { // Sign is currently OK
-            return this;
-        }
-        return negate(); // flip sign
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp copySign(final double s) {
-        long sb = Double.doubleToLongBits(s);
-        if ((sign >= 0 && sb >= 0) || (sign < 0 && sb < 0)) { // Sign is currently OK
-            return this;
-        }
-        return negate(); // flip sign
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp scalb(final int n) {
-        return multiply(DfpMath.pow(getTwo(), n));
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp hypot(final Dfp y) {
-        return multiply(this).add(y.multiply(y)).sqrt();
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp cbrt() {
-        return rootN(3);
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp rootN(final int n) {
-        return (sign >= 0) ?
-               DfpMath.pow(this, getOne().divide(n)) :
-               DfpMath.pow(negate(), getOne().divide(n)).negate();
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp pow(final double p) {
-        return DfpMath.pow(this, newInstance(p));
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp pow(final int n) {
-        return DfpMath.pow(this, n);
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp pow(final Dfp e) {
-        return DfpMath.pow(this, e);
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp exp() {
-        return DfpMath.exp(this);
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp expm1() {
-        return DfpMath.exp(this).subtract(getOne());
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp log() {
-        return DfpMath.log(this);
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp log1p() {
-        return DfpMath.log(this.add(getOne()));
-    }
-
-//  TODO: deactivate this implementation (and return type) in 4.0
-    /** Get the exponent of the greatest power of 10 that is less than or equal to abs(this).
-     *  @return integer base 10 logarithm
-     *  @deprecated as of 3.2, replaced by {@link #intLog10()}, in 4.0 the return type
-     *  will be changed to Dfp
-     */
-    @Deprecated
-    public int log10()  {
-        return intLog10();
-    }
-
-//    TODO: activate this implementation (and return type) in 4.0
-//    /** {@inheritDoc}
-//     * @since 3.2
-//     */
-//    public Dfp log10() {
-//        return DfpMath.log(this).divide(DfpMath.log(newInstance(10)));
-//    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp cos() {
-        return DfpMath.cos(this);
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp sin() {
-        return DfpMath.sin(this);
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp tan() {
-        return DfpMath.tan(this);
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp acos() {
-        return DfpMath.acos(this);
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp asin() {
-        return DfpMath.asin(this);
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp atan() {
-        return DfpMath.atan(this);
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp atan2(final Dfp x)
-        throws DimensionMismatchException {
-
-        // compute r = sqrt(x^2+y^2)
-        final Dfp r = x.multiply(x).add(multiply(this)).sqrt();
-
-        if (x.sign >= 0) {
-
-            // compute atan2(y, x) = 2 atan(y / (r + x))
-            return getTwo().multiply(divide(r.add(x)).atan());
-
-        } else {
-
-            // compute atan2(y, x) = +/- pi - 2 atan(y / (r - x))
-            final Dfp tmp = getTwo().multiply(divide(r.subtract(x)).atan());
-            final Dfp pmPi = newInstance((tmp.sign <= 0) ? -FastMath.PI : FastMath.PI);
-            return pmPi.subtract(tmp);
-
-        }
-
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp cosh() {
-        return DfpMath.exp(this).add(DfpMath.exp(negate())).divide(2);
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp sinh() {
-        return DfpMath.exp(this).subtract(DfpMath.exp(negate())).divide(2);
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp tanh() {
-        final Dfp ePlus  = DfpMath.exp(this);
-        final Dfp eMinus = DfpMath.exp(negate());
-        return ePlus.subtract(eMinus).divide(ePlus.add(eMinus));
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp acosh() {
-        return multiply(this).subtract(getOne()).sqrt().add(this).log();
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp asinh() {
-        return multiply(this).add(getOne()).sqrt().add(this).log();
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp atanh() {
-        return getOne().add(this).divide(getOne().subtract(this)).log().divide(2);
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp linearCombination(final Dfp[] a, final Dfp[] b)
-        throws DimensionMismatchException {
-        if (a.length != b.length) {
-            throw new DimensionMismatchException(a.length, b.length);
-        }
-        Dfp r = getZero();
-        for (int i = 0; i < a.length; ++i) {
-            r = r.add(a[i].multiply(b[i]));
-        }
-        return r;
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp linearCombination(final double[] a, final Dfp[] b)
-        throws DimensionMismatchException {
-        if (a.length != b.length) {
-            throw new DimensionMismatchException(a.length, b.length);
-        }
-        Dfp r = getZero();
-        for (int i = 0; i < a.length; ++i) {
-            r = r.add(b[i].multiply(a[i]));
-        }
-        return r;
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp linearCombination(final Dfp a1, final Dfp b1, final Dfp a2, final Dfp b2) {
-        return a1.multiply(b1).add(a2.multiply(b2));
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp linearCombination(final double a1, final Dfp b1, final double a2, final Dfp b2) {
-        return b1.multiply(a1).add(b2.multiply(a2));
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp linearCombination(final Dfp a1, final Dfp b1,
-                                 final Dfp a2, final Dfp b2,
-                                 final Dfp a3, final Dfp b3) {
-        return a1.multiply(b1).add(a2.multiply(b2)).add(a3.multiply(b3));
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp linearCombination(final double a1, final Dfp b1,
-                                 final double a2, final Dfp b2,
-                                 final double a3, final Dfp b3) {
-        return b1.multiply(a1).add(b2.multiply(a2)).add(b3.multiply(a3));
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp linearCombination(final Dfp a1, final Dfp b1, final Dfp a2, final Dfp b2,
-                                 final Dfp a3, final Dfp b3, final Dfp a4, final Dfp b4) {
-        return a1.multiply(b1).add(a2.multiply(b2)).add(a3.multiply(b3)).add(a4.multiply(b4));
-    }
-
-    /** {@inheritDoc}
-     * @since 3.2
-     */
-    public Dfp linearCombination(final double a1, final Dfp b1, final double a2, final Dfp b2,
-                                 final double a3, final Dfp b3, final double a4, final Dfp b4) {
-        return b1.multiply(a1).add(b2.multiply(a2)).add(b3.multiply(a3)).add(b4.multiply(a4));
-    }
-
-}