src/java.base/share/classes/java/lang/Double.java
changeset 47216 71c04702a3d5
parent 46148 6d8e27cd2f1e
child 52914 4fa75d8ad418
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/lang/Double.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,1075 @@
+/*
+ * Copyright (c) 1994, 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package java.lang;
+
+import jdk.internal.math.FloatingDecimal;
+import jdk.internal.math.DoubleConsts;
+import jdk.internal.HotSpotIntrinsicCandidate;
+
+/**
+ * The {@code Double} class wraps a value of the primitive type
+ * {@code double} in an object. An object of type
+ * {@code Double} contains a single field whose type is
+ * {@code double}.
+ *
+ * <p>In addition, this class provides several methods for converting a
+ * {@code double} to a {@code String} and a
+ * {@code String} to a {@code double}, as well as other
+ * constants and methods useful when dealing with a
+ * {@code double}.
+ *
+ * @author  Lee Boynton
+ * @author  Arthur van Hoff
+ * @author  Joseph D. Darcy
+ * @since 1.0
+ */
+public final class Double extends Number implements Comparable<Double> {
+    /**
+     * A constant holding the positive infinity of type
+     * {@code double}. It is equal to the value returned by
+     * {@code Double.longBitsToDouble(0x7ff0000000000000L)}.
+     */
+    public static final double POSITIVE_INFINITY = 1.0 / 0.0;
+
+    /**
+     * A constant holding the negative infinity of type
+     * {@code double}. It is equal to the value returned by
+     * {@code Double.longBitsToDouble(0xfff0000000000000L)}.
+     */
+    public static final double NEGATIVE_INFINITY = -1.0 / 0.0;
+
+    /**
+     * A constant holding a Not-a-Number (NaN) value of type
+     * {@code double}. It is equivalent to the value returned by
+     * {@code Double.longBitsToDouble(0x7ff8000000000000L)}.
+     */
+    public static final double NaN = 0.0d / 0.0;
+
+    /**
+     * A constant holding the largest positive finite value of type
+     * {@code double},
+     * (2-2<sup>-52</sup>)&middot;2<sup>1023</sup>.  It is equal to
+     * the hexadecimal floating-point literal
+     * {@code 0x1.fffffffffffffP+1023} and also equal to
+     * {@code Double.longBitsToDouble(0x7fefffffffffffffL)}.
+     */
+    public static final double MAX_VALUE = 0x1.fffffffffffffP+1023; // 1.7976931348623157e+308
+
+    /**
+     * A constant holding the smallest positive normal value of type
+     * {@code double}, 2<sup>-1022</sup>.  It is equal to the
+     * hexadecimal floating-point literal {@code 0x1.0p-1022} and also
+     * equal to {@code Double.longBitsToDouble(0x0010000000000000L)}.
+     *
+     * @since 1.6
+     */
+    public static final double MIN_NORMAL = 0x1.0p-1022; // 2.2250738585072014E-308
+
+    /**
+     * A constant holding the smallest positive nonzero value of type
+     * {@code double}, 2<sup>-1074</sup>. It is equal to the
+     * hexadecimal floating-point literal
+     * {@code 0x0.0000000000001P-1022} and also equal to
+     * {@code Double.longBitsToDouble(0x1L)}.
+     */
+    public static final double MIN_VALUE = 0x0.0000000000001P-1022; // 4.9e-324
+
+    /**
+     * Maximum exponent a finite {@code double} variable may have.
+     * It is equal to the value returned by
+     * {@code Math.getExponent(Double.MAX_VALUE)}.
+     *
+     * @since 1.6
+     */
+    public static final int MAX_EXPONENT = 1023;
+
+    /**
+     * Minimum exponent a normalized {@code double} variable may
+     * have.  It is equal to the value returned by
+     * {@code Math.getExponent(Double.MIN_NORMAL)}.
+     *
+     * @since 1.6
+     */
+    public static final int MIN_EXPONENT = -1022;
+
+    /**
+     * The number of bits used to represent a {@code double} value.
+     *
+     * @since 1.5
+     */
+    public static final int SIZE = 64;
+
+    /**
+     * The number of bytes used to represent a {@code double} value.
+     *
+     * @since 1.8
+     */
+    public static final int BYTES = SIZE / Byte.SIZE;
+
+    /**
+     * The {@code Class} instance representing the primitive type
+     * {@code double}.
+     *
+     * @since 1.1
+     */
+    @SuppressWarnings("unchecked")
+    public static final Class<Double>   TYPE = (Class<Double>) Class.getPrimitiveClass("double");
+
+    /**
+     * Returns a string representation of the {@code double}
+     * argument. All characters mentioned below are ASCII characters.
+     * <ul>
+     * <li>If the argument is NaN, the result is the string
+     *     "{@code NaN}".
+     * <li>Otherwise, the result is a string that represents the sign and
+     * magnitude (absolute value) of the argument. If the sign is negative,
+     * the first character of the result is '{@code -}'
+     * ({@code '\u005Cu002D'}); if the sign is positive, no sign character
+     * appears in the result. As for the magnitude <i>m</i>:
+     * <ul>
+     * <li>If <i>m</i> is infinity, it is represented by the characters
+     * {@code "Infinity"}; thus, positive infinity produces the result
+     * {@code "Infinity"} and negative infinity produces the result
+     * {@code "-Infinity"}.
+     *
+     * <li>If <i>m</i> is zero, it is represented by the characters
+     * {@code "0.0"}; thus, negative zero produces the result
+     * {@code "-0.0"} and positive zero produces the result
+     * {@code "0.0"}.
+     *
+     * <li>If <i>m</i> is greater than or equal to 10<sup>-3</sup> but less
+     * than 10<sup>7</sup>, then it is represented as the integer part of
+     * <i>m</i>, in decimal form with no leading zeroes, followed by
+     * '{@code .}' ({@code '\u005Cu002E'}), followed by one or
+     * more decimal digits representing the fractional part of <i>m</i>.
+     *
+     * <li>If <i>m</i> is less than 10<sup>-3</sup> or greater than or
+     * equal to 10<sup>7</sup>, then it is represented in so-called
+     * "computerized scientific notation." Let <i>n</i> be the unique
+     * integer such that 10<sup><i>n</i></sup> &le; <i>m</i> {@literal <}
+     * 10<sup><i>n</i>+1</sup>; then let <i>a</i> be the
+     * mathematically exact quotient of <i>m</i> and
+     * 10<sup><i>n</i></sup> so that 1 &le; <i>a</i> {@literal <} 10. The
+     * magnitude is then represented as the integer part of <i>a</i>,
+     * as a single decimal digit, followed by '{@code .}'
+     * ({@code '\u005Cu002E'}), followed by decimal digits
+     * representing the fractional part of <i>a</i>, followed by the
+     * letter '{@code E}' ({@code '\u005Cu0045'}), followed
+     * by a representation of <i>n</i> as a decimal integer, as
+     * produced by the method {@link Integer#toString(int)}.
+     * </ul>
+     * </ul>
+     * How many digits must be printed for the fractional part of
+     * <i>m</i> or <i>a</i>? There must be at least one digit to represent
+     * the fractional part, and beyond that as many, but only as many, more
+     * digits as are needed to uniquely distinguish the argument value from
+     * adjacent values of type {@code double}. That is, suppose that
+     * <i>x</i> is the exact mathematical value represented by the decimal
+     * representation produced by this method for a finite nonzero argument
+     * <i>d</i>. Then <i>d</i> must be the {@code double} value nearest
+     * to <i>x</i>; or if two {@code double} values are equally close
+     * to <i>x</i>, then <i>d</i> must be one of them and the least
+     * significant bit of the significand of <i>d</i> must be {@code 0}.
+     *
+     * <p>To create localized string representations of a floating-point
+     * value, use subclasses of {@link java.text.NumberFormat}.
+     *
+     * @param   d   the {@code double} to be converted.
+     * @return a string representation of the argument.
+     */
+    public static String toString(double d) {
+        return FloatingDecimal.toJavaFormatString(d);
+    }
+
+    /**
+     * Returns a hexadecimal string representation of the
+     * {@code double} argument. All characters mentioned below
+     * are ASCII characters.
+     *
+     * <ul>
+     * <li>If the argument is NaN, the result is the string
+     *     "{@code NaN}".
+     * <li>Otherwise, the result is a string that represents the sign
+     * and magnitude of the argument. If the sign is negative, the
+     * first character of the result is '{@code -}'
+     * ({@code '\u005Cu002D'}); if the sign is positive, no sign
+     * character appears in the result. As for the magnitude <i>m</i>:
+     *
+     * <ul>
+     * <li>If <i>m</i> is infinity, it is represented by the string
+     * {@code "Infinity"}; thus, positive infinity produces the
+     * result {@code "Infinity"} and negative infinity produces
+     * the result {@code "-Infinity"}.
+     *
+     * <li>If <i>m</i> is zero, it is represented by the string
+     * {@code "0x0.0p0"}; thus, negative zero produces the result
+     * {@code "-0x0.0p0"} and positive zero produces the result
+     * {@code "0x0.0p0"}.
+     *
+     * <li>If <i>m</i> is a {@code double} value with a
+     * normalized representation, substrings are used to represent the
+     * significand and exponent fields.  The significand is
+     * represented by the characters {@code "0x1."}
+     * followed by a lowercase hexadecimal representation of the rest
+     * of the significand as a fraction.  Trailing zeros in the
+     * hexadecimal representation are removed unless all the digits
+     * are zero, in which case a single zero is used. Next, the
+     * exponent is represented by {@code "p"} followed
+     * by a decimal string of the unbiased exponent as if produced by
+     * a call to {@link Integer#toString(int) Integer.toString} on the
+     * exponent value.
+     *
+     * <li>If <i>m</i> is a {@code double} value with a subnormal
+     * representation, the significand is represented by the
+     * characters {@code "0x0."} followed by a
+     * hexadecimal representation of the rest of the significand as a
+     * fraction.  Trailing zeros in the hexadecimal representation are
+     * removed. Next, the exponent is represented by
+     * {@code "p-1022"}.  Note that there must be at
+     * least one nonzero digit in a subnormal significand.
+     *
+     * </ul>
+     *
+     * </ul>
+     *
+     * <table class="striped">
+     * <caption>Examples</caption>
+     * <thead>
+     * <tr><th scope="col">Floating-point Value</th><th scope="col">Hexadecimal String</th>
+     * </thead>
+     * <tbody style="text-align:right">
+     * <tr><th scope="row">{@code 1.0}</th> <td>{@code 0x1.0p0}</td>
+     * <tr><th scope="row">{@code -1.0}</th>        <td>{@code -0x1.0p0}</td>
+     * <tr><th scope="row">{@code 2.0}</th> <td>{@code 0x1.0p1}</td>
+     * <tr><th scope="row">{@code 3.0}</th> <td>{@code 0x1.8p1}</td>
+     * <tr><th scope="row">{@code 0.5}</th> <td>{@code 0x1.0p-1}</td>
+     * <tr><th scope="row">{@code 0.25}</th>        <td>{@code 0x1.0p-2}</td>
+     * <tr><th scope="row">{@code Double.MAX_VALUE}</th>
+     *     <td>{@code 0x1.fffffffffffffp1023}</td>
+     * <tr><th scope="row">{@code Minimum Normal Value}</th>
+     *     <td>{@code 0x1.0p-1022}</td>
+     * <tr><th scope="row">{@code Maximum Subnormal Value}</th>
+     *     <td>{@code 0x0.fffffffffffffp-1022}</td>
+     * <tr><th scope="row">{@code Double.MIN_VALUE}</th>
+     *     <td>{@code 0x0.0000000000001p-1022}</td>
+     * </tbody>
+     * </table>
+     * @param   d   the {@code double} to be converted.
+     * @return a hex string representation of the argument.
+     * @since 1.5
+     * @author Joseph D. Darcy
+     */
+    public static String toHexString(double d) {
+        /*
+         * Modeled after the "a" conversion specifier in C99, section
+         * 7.19.6.1; however, the output of this method is more
+         * tightly specified.
+         */
+        if (!isFinite(d) )
+            // For infinity and NaN, use the decimal output.
+            return Double.toString(d);
+        else {
+            // Initialized to maximum size of output.
+            StringBuilder answer = new StringBuilder(24);
+
+            if (Math.copySign(1.0, d) == -1.0)    // value is negative,
+                answer.append("-");                  // so append sign info
+
+            answer.append("0x");
+
+            d = Math.abs(d);
+
+            if(d == 0.0) {
+                answer.append("0.0p0");
+            } else {
+                boolean subnormal = (d < Double.MIN_NORMAL);
+
+                // Isolate significand bits and OR in a high-order bit
+                // so that the string representation has a known
+                // length.
+                long signifBits = (Double.doubleToLongBits(d)
+                                   & DoubleConsts.SIGNIF_BIT_MASK) |
+                    0x1000000000000000L;
+
+                // Subnormal values have a 0 implicit bit; normal
+                // values have a 1 implicit bit.
+                answer.append(subnormal ? "0." : "1.");
+
+                // Isolate the low-order 13 digits of the hex
+                // representation.  If all the digits are zero,
+                // replace with a single 0; otherwise, remove all
+                // trailing zeros.
+                String signif = Long.toHexString(signifBits).substring(3,16);
+                answer.append(signif.equals("0000000000000") ? // 13 zeros
+                              "0":
+                              signif.replaceFirst("0{1,12}$", ""));
+
+                answer.append('p');
+                // If the value is subnormal, use the E_min exponent
+                // value for double; otherwise, extract and report d's
+                // exponent (the representation of a subnormal uses
+                // E_min -1).
+                answer.append(subnormal ?
+                              Double.MIN_EXPONENT:
+                              Math.getExponent(d));
+            }
+            return answer.toString();
+        }
+    }
+
+    /**
+     * Returns a {@code Double} object holding the
+     * {@code double} value represented by the argument string
+     * {@code s}.
+     *
+     * <p>If {@code s} is {@code null}, then a
+     * {@code NullPointerException} is thrown.
+     *
+     * <p>Leading and trailing whitespace characters in {@code s}
+     * are ignored.  Whitespace is removed as if by the {@link
+     * String#trim} method; that is, both ASCII space and control
+     * characters are removed. The rest of {@code s} should
+     * constitute a <i>FloatValue</i> as described by the lexical
+     * syntax rules:
+     *
+     * <blockquote>
+     * <dl>
+     * <dt><i>FloatValue:</i>
+     * <dd><i>Sign<sub>opt</sub></i> {@code NaN}
+     * <dd><i>Sign<sub>opt</sub></i> {@code Infinity}
+     * <dd><i>Sign<sub>opt</sub> FloatingPointLiteral</i>
+     * <dd><i>Sign<sub>opt</sub> HexFloatingPointLiteral</i>
+     * <dd><i>SignedInteger</i>
+     * </dl>
+     *
+     * <dl>
+     * <dt><i>HexFloatingPointLiteral</i>:
+     * <dd> <i>HexSignificand BinaryExponent FloatTypeSuffix<sub>opt</sub></i>
+     * </dl>
+     *
+     * <dl>
+     * <dt><i>HexSignificand:</i>
+     * <dd><i>HexNumeral</i>
+     * <dd><i>HexNumeral</i> {@code .}
+     * <dd>{@code 0x} <i>HexDigits<sub>opt</sub>
+     *     </i>{@code .}<i> HexDigits</i>
+     * <dd>{@code 0X}<i> HexDigits<sub>opt</sub>
+     *     </i>{@code .} <i>HexDigits</i>
+     * </dl>
+     *
+     * <dl>
+     * <dt><i>BinaryExponent:</i>
+     * <dd><i>BinaryExponentIndicator SignedInteger</i>
+     * </dl>
+     *
+     * <dl>
+     * <dt><i>BinaryExponentIndicator:</i>
+     * <dd>{@code p}
+     * <dd>{@code P}
+     * </dl>
+     *
+     * </blockquote>
+     *
+     * where <i>Sign</i>, <i>FloatingPointLiteral</i>,
+     * <i>HexNumeral</i>, <i>HexDigits</i>, <i>SignedInteger</i> and
+     * <i>FloatTypeSuffix</i> are as defined in the lexical structure
+     * sections of
+     * <cite>The Java&trade; Language Specification</cite>,
+     * except that underscores are not accepted between digits.
+     * If {@code s} does not have the form of
+     * a <i>FloatValue</i>, then a {@code NumberFormatException}
+     * is thrown. Otherwise, {@code s} is regarded as
+     * representing an exact decimal value in the usual
+     * "computerized scientific notation" or as an exact
+     * hexadecimal value; this exact numerical value is then
+     * conceptually converted to an "infinitely precise"
+     * binary value that is then rounded to type {@code double}
+     * by the usual round-to-nearest rule of IEEE 754 floating-point
+     * arithmetic, which includes preserving the sign of a zero
+     * value.
+     *
+     * Note that the round-to-nearest rule also implies overflow and
+     * underflow behaviour; if the exact value of {@code s} is large
+     * enough in magnitude (greater than or equal to ({@link
+     * #MAX_VALUE} + {@link Math#ulp(double) ulp(MAX_VALUE)}/2),
+     * rounding to {@code double} will result in an infinity and if the
+     * exact value of {@code s} is small enough in magnitude (less
+     * than or equal to {@link #MIN_VALUE}/2), rounding to float will
+     * result in a zero.
+     *
+     * Finally, after rounding a {@code Double} object representing
+     * this {@code double} value is returned.
+     *
+     * <p> To interpret localized string representations of a
+     * floating-point value, use subclasses of {@link
+     * java.text.NumberFormat}.
+     *
+     * <p>Note that trailing format specifiers, specifiers that
+     * determine the type of a floating-point literal
+     * ({@code 1.0f} is a {@code float} value;
+     * {@code 1.0d} is a {@code double} value), do
+     * <em>not</em> influence the results of this method.  In other
+     * words, the numerical value of the input string is converted
+     * directly to the target floating-point type.  The two-step
+     * sequence of conversions, string to {@code float} followed
+     * by {@code float} to {@code double}, is <em>not</em>
+     * equivalent to converting a string directly to
+     * {@code double}. For example, the {@code float}
+     * literal {@code 0.1f} is equal to the {@code double}
+     * value {@code 0.10000000149011612}; the {@code float}
+     * literal {@code 0.1f} represents a different numerical
+     * value than the {@code double} literal
+     * {@code 0.1}. (The numerical value 0.1 cannot be exactly
+     * represented in a binary floating-point number.)
+     *
+     * <p>To avoid calling this method on an invalid string and having
+     * a {@code NumberFormatException} be thrown, the regular
+     * expression below can be used to screen the input string:
+     *
+     * <pre>{@code
+     *  final String Digits     = "(\\p{Digit}+)";
+     *  final String HexDigits  = "(\\p{XDigit}+)";
+     *  // an exponent is 'e' or 'E' followed by an optionally
+     *  // signed decimal integer.
+     *  final String Exp        = "[eE][+-]?"+Digits;
+     *  final String fpRegex    =
+     *      ("[\\x00-\\x20]*"+  // Optional leading "whitespace"
+     *       "[+-]?(" + // Optional sign character
+     *       "NaN|" +           // "NaN" string
+     *       "Infinity|" +      // "Infinity" string
+     *
+     *       // A decimal floating-point string representing a finite positive
+     *       // number without a leading sign has at most five basic pieces:
+     *       // Digits . Digits ExponentPart FloatTypeSuffix
+     *       //
+     *       // Since this method allows integer-only strings as input
+     *       // in addition to strings of floating-point literals, the
+     *       // two sub-patterns below are simplifications of the grammar
+     *       // productions from section 3.10.2 of
+     *       // The Java Language Specification.
+     *
+     *       // Digits ._opt Digits_opt ExponentPart_opt FloatTypeSuffix_opt
+     *       "((("+Digits+"(\\.)?("+Digits+"?)("+Exp+")?)|"+
+     *
+     *       // . Digits ExponentPart_opt FloatTypeSuffix_opt
+     *       "(\\.("+Digits+")("+Exp+")?)|"+
+     *
+     *       // Hexadecimal strings
+     *       "((" +
+     *        // 0[xX] HexDigits ._opt BinaryExponent FloatTypeSuffix_opt
+     *        "(0[xX]" + HexDigits + "(\\.)?)|" +
+     *
+     *        // 0[xX] HexDigits_opt . HexDigits BinaryExponent FloatTypeSuffix_opt
+     *        "(0[xX]" + HexDigits + "?(\\.)" + HexDigits + ")" +
+     *
+     *        ")[pP][+-]?" + Digits + "))" +
+     *       "[fFdD]?))" +
+     *       "[\\x00-\\x20]*");// Optional trailing "whitespace"
+     *
+     *  if (Pattern.matches(fpRegex, myString))
+     *      Double.valueOf(myString); // Will not throw NumberFormatException
+     *  else {
+     *      // Perform suitable alternative action
+     *  }
+     * }</pre>
+     *
+     * @param      s   the string to be parsed.
+     * @return     a {@code Double} object holding the value
+     *             represented by the {@code String} argument.
+     * @throws     NumberFormatException  if the string does not contain a
+     *             parsable number.
+     */
+    public static Double valueOf(String s) throws NumberFormatException {
+        return new Double(parseDouble(s));
+    }
+
+    /**
+     * Returns a {@code Double} instance representing the specified
+     * {@code double} value.
+     * If a new {@code Double} instance is not required, this method
+     * should generally be used in preference to the constructor
+     * {@link #Double(double)}, as this method is likely to yield
+     * significantly better space and time performance by caching
+     * frequently requested values.
+     *
+     * @param  d a double value.
+     * @return a {@code Double} instance representing {@code d}.
+     * @since  1.5
+     */
+    @HotSpotIntrinsicCandidate
+    public static Double valueOf(double d) {
+        return new Double(d);
+    }
+
+    /**
+     * Returns a new {@code double} initialized to the value
+     * represented by the specified {@code String}, as performed
+     * by the {@code valueOf} method of class
+     * {@code Double}.
+     *
+     * @param  s   the string to be parsed.
+     * @return the {@code double} value represented by the string
+     *         argument.
+     * @throws NullPointerException  if the string is null
+     * @throws NumberFormatException if the string does not contain
+     *         a parsable {@code double}.
+     * @see    java.lang.Double#valueOf(String)
+     * @since 1.2
+     */
+    public static double parseDouble(String s) throws NumberFormatException {
+        return FloatingDecimal.parseDouble(s);
+    }
+
+    /**
+     * Returns {@code true} if the specified number is a
+     * Not-a-Number (NaN) value, {@code false} otherwise.
+     *
+     * @param   v   the value to be tested.
+     * @return  {@code true} if the value of the argument is NaN;
+     *          {@code false} otherwise.
+     */
+    public static boolean isNaN(double v) {
+        return (v != v);
+    }
+
+    /**
+     * Returns {@code true} if the specified number is infinitely
+     * large in magnitude, {@code false} otherwise.
+     *
+     * @param   v   the value to be tested.
+     * @return  {@code true} if the value of the argument is positive
+     *          infinity or negative infinity; {@code false} otherwise.
+     */
+    public static boolean isInfinite(double v) {
+        return (v == POSITIVE_INFINITY) || (v == NEGATIVE_INFINITY);
+    }
+
+    /**
+     * Returns {@code true} if the argument is a finite floating-point
+     * value; returns {@code false} otherwise (for NaN and infinity
+     * arguments).
+     *
+     * @param d the {@code double} value to be tested
+     * @return {@code true} if the argument is a finite
+     * floating-point value, {@code false} otherwise.
+     * @since 1.8
+     */
+    public static boolean isFinite(double d) {
+        return Math.abs(d) <= Double.MAX_VALUE;
+    }
+
+    /**
+     * The value of the Double.
+     *
+     * @serial
+     */
+    private final double value;
+
+    /**
+     * Constructs a newly allocated {@code Double} object that
+     * represents the primitive {@code double} argument.
+     *
+     * @param   value   the value to be represented by the {@code Double}.
+     *
+     * @deprecated
+     * It is rarely appropriate to use this constructor. The static factory
+     * {@link #valueOf(double)} is generally a better choice, as it is
+     * likely to yield significantly better space and time performance.
+     */
+    @Deprecated(since="9")
+    public Double(double value) {
+        this.value = value;
+    }
+
+    /**
+     * Constructs a newly allocated {@code Double} object that
+     * represents the floating-point value of type {@code double}
+     * represented by the string. The string is converted to a
+     * {@code double} value as if by the {@code valueOf} method.
+     *
+     * @param  s  a string to be converted to a {@code Double}.
+     * @throws    NumberFormatException if the string does not contain a
+     *            parsable number.
+     *
+     * @deprecated
+     * It is rarely appropriate to use this constructor.
+     * Use {@link #parseDouble(String)} to convert a string to a
+     * {@code double} primitive, or use {@link #valueOf(String)}
+     * to convert a string to a {@code Double} object.
+     */
+    @Deprecated(since="9")
+    public Double(String s) throws NumberFormatException {
+        value = parseDouble(s);
+    }
+
+    /**
+     * Returns {@code true} if this {@code Double} value is
+     * a Not-a-Number (NaN), {@code false} otherwise.
+     *
+     * @return  {@code true} if the value represented by this object is
+     *          NaN; {@code false} otherwise.
+     */
+    public boolean isNaN() {
+        return isNaN(value);
+    }
+
+    /**
+     * Returns {@code true} if this {@code Double} value is
+     * infinitely large in magnitude, {@code false} otherwise.
+     *
+     * @return  {@code true} if the value represented by this object is
+     *          positive infinity or negative infinity;
+     *          {@code false} otherwise.
+     */
+    public boolean isInfinite() {
+        return isInfinite(value);
+    }
+
+    /**
+     * Returns a string representation of this {@code Double} object.
+     * The primitive {@code double} value represented by this
+     * object is converted to a string exactly as if by the method
+     * {@code toString} of one argument.
+     *
+     * @return  a {@code String} representation of this object.
+     * @see java.lang.Double#toString(double)
+     */
+    public String toString() {
+        return toString(value);
+    }
+
+    /**
+     * Returns the value of this {@code Double} as a {@code byte}
+     * after a narrowing primitive conversion.
+     *
+     * @return  the {@code double} value represented by this object
+     *          converted to type {@code byte}
+     * @jls 5.1.3 Narrowing Primitive Conversions
+     * @since 1.1
+     */
+    public byte byteValue() {
+        return (byte)value;
+    }
+
+    /**
+     * Returns the value of this {@code Double} as a {@code short}
+     * after a narrowing primitive conversion.
+     *
+     * @return  the {@code double} value represented by this object
+     *          converted to type {@code short}
+     * @jls 5.1.3 Narrowing Primitive Conversions
+     * @since 1.1
+     */
+    public short shortValue() {
+        return (short)value;
+    }
+
+    /**
+     * Returns the value of this {@code Double} as an {@code int}
+     * after a narrowing primitive conversion.
+     * @jls 5.1.3 Narrowing Primitive Conversions
+     *
+     * @return  the {@code double} value represented by this object
+     *          converted to type {@code int}
+     */
+    public int intValue() {
+        return (int)value;
+    }
+
+    /**
+     * Returns the value of this {@code Double} as a {@code long}
+     * after a narrowing primitive conversion.
+     *
+     * @return  the {@code double} value represented by this object
+     *          converted to type {@code long}
+     * @jls 5.1.3 Narrowing Primitive Conversions
+     */
+    public long longValue() {
+        return (long)value;
+    }
+
+    /**
+     * Returns the value of this {@code Double} as a {@code float}
+     * after a narrowing primitive conversion.
+     *
+     * @return  the {@code double} value represented by this object
+     *          converted to type {@code float}
+     * @jls 5.1.3 Narrowing Primitive Conversions
+     * @since 1.0
+     */
+    public float floatValue() {
+        return (float)value;
+    }
+
+    /**
+     * Returns the {@code double} value of this {@code Double} object.
+     *
+     * @return the {@code double} value represented by this object
+     */
+    @HotSpotIntrinsicCandidate
+    public double doubleValue() {
+        return value;
+    }
+
+    /**
+     * Returns a hash code for this {@code Double} object. The
+     * result is the exclusive OR of the two halves of the
+     * {@code long} integer bit representation, exactly as
+     * produced by the method {@link #doubleToLongBits(double)}, of
+     * the primitive {@code double} value represented by this
+     * {@code Double} object. That is, the hash code is the value
+     * of the expression:
+     *
+     * <blockquote>
+     *  {@code (int)(v^(v>>>32))}
+     * </blockquote>
+     *
+     * where {@code v} is defined by:
+     *
+     * <blockquote>
+     *  {@code long v = Double.doubleToLongBits(this.doubleValue());}
+     * </blockquote>
+     *
+     * @return  a {@code hash code} value for this object.
+     */
+    @Override
+    public int hashCode() {
+        return Double.hashCode(value);
+    }
+
+    /**
+     * Returns a hash code for a {@code double} value; compatible with
+     * {@code Double.hashCode()}.
+     *
+     * @param value the value to hash
+     * @return a hash code value for a {@code double} value.
+     * @since 1.8
+     */
+    public static int hashCode(double value) {
+        long bits = doubleToLongBits(value);
+        return (int)(bits ^ (bits >>> 32));
+    }
+
+    /**
+     * Compares this object against the specified object.  The result
+     * is {@code true} if and only if the argument is not
+     * {@code null} and is a {@code Double} object that
+     * represents a {@code double} that has the same value as the
+     * {@code double} represented by this object. For this
+     * purpose, two {@code double} values are considered to be
+     * the same if and only if the method {@link
+     * #doubleToLongBits(double)} returns the identical
+     * {@code long} value when applied to each.
+     *
+     * <p>Note that in most cases, for two instances of class
+     * {@code Double}, {@code d1} and {@code d2}, the
+     * value of {@code d1.equals(d2)} is {@code true} if and
+     * only if
+     *
+     * <blockquote>
+     *  {@code d1.doubleValue() == d2.doubleValue()}
+     * </blockquote>
+     *
+     * <p>also has the value {@code true}. However, there are two
+     * exceptions:
+     * <ul>
+     * <li>If {@code d1} and {@code d2} both represent
+     *     {@code Double.NaN}, then the {@code equals} method
+     *     returns {@code true}, even though
+     *     {@code Double.NaN==Double.NaN} has the value
+     *     {@code false}.
+     * <li>If {@code d1} represents {@code +0.0} while
+     *     {@code d2} represents {@code -0.0}, or vice versa,
+     *     the {@code equal} test has the value {@code false},
+     *     even though {@code +0.0==-0.0} has the value {@code true}.
+     * </ul>
+     * This definition allows hash tables to operate properly.
+     * @param   obj   the object to compare with.
+     * @return  {@code true} if the objects are the same;
+     *          {@code false} otherwise.
+     * @see java.lang.Double#doubleToLongBits(double)
+     */
+    public boolean equals(Object obj) {
+        return (obj instanceof Double)
+               && (doubleToLongBits(((Double)obj).value) ==
+                      doubleToLongBits(value));
+    }
+
+    /**
+     * Returns a representation of the specified floating-point value
+     * according to the IEEE 754 floating-point "double
+     * format" bit layout.
+     *
+     * <p>Bit 63 (the bit that is selected by the mask
+     * {@code 0x8000000000000000L}) represents the sign of the
+     * floating-point number. Bits
+     * 62-52 (the bits that are selected by the mask
+     * {@code 0x7ff0000000000000L}) represent the exponent. Bits 51-0
+     * (the bits that are selected by the mask
+     * {@code 0x000fffffffffffffL}) represent the significand
+     * (sometimes called the mantissa) of the floating-point number.
+     *
+     * <p>If the argument is positive infinity, the result is
+     * {@code 0x7ff0000000000000L}.
+     *
+     * <p>If the argument is negative infinity, the result is
+     * {@code 0xfff0000000000000L}.
+     *
+     * <p>If the argument is NaN, the result is
+     * {@code 0x7ff8000000000000L}.
+     *
+     * <p>In all cases, the result is a {@code long} integer that, when
+     * given to the {@link #longBitsToDouble(long)} method, will produce a
+     * floating-point value the same as the argument to
+     * {@code doubleToLongBits} (except all NaN values are
+     * collapsed to a single "canonical" NaN value).
+     *
+     * @param   value   a {@code double} precision floating-point number.
+     * @return the bits that represent the floating-point number.
+     */
+    @HotSpotIntrinsicCandidate
+    public static long doubleToLongBits(double value) {
+        if (!isNaN(value)) {
+            return doubleToRawLongBits(value);
+        }
+        return 0x7ff8000000000000L;
+    }
+
+    /**
+     * Returns a representation of the specified floating-point value
+     * according to the IEEE 754 floating-point "double
+     * format" bit layout, preserving Not-a-Number (NaN) values.
+     *
+     * <p>Bit 63 (the bit that is selected by the mask
+     * {@code 0x8000000000000000L}) represents the sign of the
+     * floating-point number. Bits
+     * 62-52 (the bits that are selected by the mask
+     * {@code 0x7ff0000000000000L}) represent the exponent. Bits 51-0
+     * (the bits that are selected by the mask
+     * {@code 0x000fffffffffffffL}) represent the significand
+     * (sometimes called the mantissa) of the floating-point number.
+     *
+     * <p>If the argument is positive infinity, the result is
+     * {@code 0x7ff0000000000000L}.
+     *
+     * <p>If the argument is negative infinity, the result is
+     * {@code 0xfff0000000000000L}.
+     *
+     * <p>If the argument is NaN, the result is the {@code long}
+     * integer representing the actual NaN value.  Unlike the
+     * {@code doubleToLongBits} method,
+     * {@code doubleToRawLongBits} does not collapse all the bit
+     * patterns encoding a NaN to a single "canonical" NaN
+     * value.
+     *
+     * <p>In all cases, the result is a {@code long} integer that,
+     * when given to the {@link #longBitsToDouble(long)} method, will
+     * produce a floating-point value the same as the argument to
+     * {@code doubleToRawLongBits}.
+     *
+     * @param   value   a {@code double} precision floating-point number.
+     * @return the bits that represent the floating-point number.
+     * @since 1.3
+     */
+    @HotSpotIntrinsicCandidate
+    public static native long doubleToRawLongBits(double value);
+
+    /**
+     * Returns the {@code double} value corresponding to a given
+     * bit representation.
+     * The argument is considered to be a representation of a
+     * floating-point value according to the IEEE 754 floating-point
+     * "double format" bit layout.
+     *
+     * <p>If the argument is {@code 0x7ff0000000000000L}, the result
+     * is positive infinity.
+     *
+     * <p>If the argument is {@code 0xfff0000000000000L}, the result
+     * is negative infinity.
+     *
+     * <p>If the argument is any value in the range
+     * {@code 0x7ff0000000000001L} through
+     * {@code 0x7fffffffffffffffL} or in the range
+     * {@code 0xfff0000000000001L} through
+     * {@code 0xffffffffffffffffL}, the result is a NaN.  No IEEE
+     * 754 floating-point operation provided by Java can distinguish
+     * between two NaN values of the same type with different bit
+     * patterns.  Distinct values of NaN are only distinguishable by
+     * use of the {@code Double.doubleToRawLongBits} method.
+     *
+     * <p>In all other cases, let <i>s</i>, <i>e</i>, and <i>m</i> be three
+     * values that can be computed from the argument:
+     *
+     * <blockquote><pre>{@code
+     * int s = ((bits >> 63) == 0) ? 1 : -1;
+     * int e = (int)((bits >> 52) & 0x7ffL);
+     * long m = (e == 0) ?
+     *                 (bits & 0xfffffffffffffL) << 1 :
+     *                 (bits & 0xfffffffffffffL) | 0x10000000000000L;
+     * }</pre></blockquote>
+     *
+     * Then the floating-point result equals the value of the mathematical
+     * expression <i>s</i>&middot;<i>m</i>&middot;2<sup><i>e</i>-1075</sup>.
+     *
+     * <p>Note that this method may not be able to return a
+     * {@code double} NaN with exactly same bit pattern as the
+     * {@code long} argument.  IEEE 754 distinguishes between two
+     * kinds of NaNs, quiet NaNs and <i>signaling NaNs</i>.  The
+     * differences between the two kinds of NaN are generally not
+     * visible in Java.  Arithmetic operations on signaling NaNs turn
+     * them into quiet NaNs with a different, but often similar, bit
+     * pattern.  However, on some processors merely copying a
+     * signaling NaN also performs that conversion.  In particular,
+     * copying a signaling NaN to return it to the calling method
+     * may perform this conversion.  So {@code longBitsToDouble}
+     * may not be able to return a {@code double} with a
+     * signaling NaN bit pattern.  Consequently, for some
+     * {@code long} values,
+     * {@code doubleToRawLongBits(longBitsToDouble(start))} may
+     * <i>not</i> equal {@code start}.  Moreover, which
+     * particular bit patterns represent signaling NaNs is platform
+     * dependent; although all NaN bit patterns, quiet or signaling,
+     * must be in the NaN range identified above.
+     *
+     * @param   bits   any {@code long} integer.
+     * @return  the {@code double} floating-point value with the same
+     *          bit pattern.
+     */
+    @HotSpotIntrinsicCandidate
+    public static native double longBitsToDouble(long bits);
+
+    /**
+     * Compares two {@code Double} objects numerically.  There
+     * are two ways in which comparisons performed by this method
+     * differ from those performed by the Java language numerical
+     * comparison operators ({@code <, <=, ==, >=, >})
+     * when applied to primitive {@code double} values:
+     * <ul><li>
+     *          {@code Double.NaN} is considered by this method
+     *          to be equal to itself and greater than all other
+     *          {@code double} values (including
+     *          {@code Double.POSITIVE_INFINITY}).
+     * <li>
+     *          {@code 0.0d} is considered by this method to be greater
+     *          than {@code -0.0d}.
+     * </ul>
+     * This ensures that the <i>natural ordering</i> of
+     * {@code Double} objects imposed by this method is <i>consistent
+     * with equals</i>.
+     *
+     * @param   anotherDouble   the {@code Double} to be compared.
+     * @return  the value {@code 0} if {@code anotherDouble} is
+     *          numerically equal to this {@code Double}; a value
+     *          less than {@code 0} if this {@code Double}
+     *          is numerically less than {@code anotherDouble};
+     *          and a value greater than {@code 0} if this
+     *          {@code Double} is numerically greater than
+     *          {@code anotherDouble}.
+     *
+     * @since   1.2
+     */
+    public int compareTo(Double anotherDouble) {
+        return Double.compare(value, anotherDouble.value);
+    }
+
+    /**
+     * Compares the two specified {@code double} values. The sign
+     * of the integer value returned is the same as that of the
+     * integer that would be returned by the call:
+     * <pre>
+     *    new Double(d1).compareTo(new Double(d2))
+     * </pre>
+     *
+     * @param   d1        the first {@code double} to compare
+     * @param   d2        the second {@code double} to compare
+     * @return  the value {@code 0} if {@code d1} is
+     *          numerically equal to {@code d2}; a value less than
+     *          {@code 0} if {@code d1} is numerically less than
+     *          {@code d2}; and a value greater than {@code 0}
+     *          if {@code d1} is numerically greater than
+     *          {@code d2}.
+     * @since 1.4
+     */
+    public static int compare(double d1, double d2) {
+        if (d1 < d2)
+            return -1;           // Neither val is NaN, thisVal is smaller
+        if (d1 > d2)
+            return 1;            // Neither val is NaN, thisVal is larger
+
+        // Cannot use doubleToRawLongBits because of possibility of NaNs.
+        long thisBits    = Double.doubleToLongBits(d1);
+        long anotherBits = Double.doubleToLongBits(d2);
+
+        return (thisBits == anotherBits ?  0 : // Values are equal
+                (thisBits < anotherBits ? -1 : // (-0.0, 0.0) or (!NaN, NaN)
+                 1));                          // (0.0, -0.0) or (NaN, !NaN)
+    }
+
+    /**
+     * Adds two {@code double} values together as per the + operator.
+     *
+     * @param a the first operand
+     * @param b the second operand
+     * @return the sum of {@code a} and {@code b}
+     * @jls 4.2.4 Floating-Point Operations
+     * @see java.util.function.BinaryOperator
+     * @since 1.8
+     */
+    public static double sum(double a, double b) {
+        return a + b;
+    }
+
+    /**
+     * Returns the greater of two {@code double} values
+     * as if by calling {@link Math#max(double, double) Math.max}.
+     *
+     * @param a the first operand
+     * @param b the second operand
+     * @return the greater of {@code a} and {@code b}
+     * @see java.util.function.BinaryOperator
+     * @since 1.8
+     */
+    public static double max(double a, double b) {
+        return Math.max(a, b);
+    }
+
+    /**
+     * Returns the smaller of two {@code double} values
+     * as if by calling {@link Math#min(double, double) Math.min}.
+     *
+     * @param a the first operand
+     * @param b the second operand
+     * @return the smaller of {@code a} and {@code b}.
+     * @see java.util.function.BinaryOperator
+     * @since 1.8
+     */
+    public static double min(double a, double b) {
+        return Math.min(a, b);
+    }
+
+    /** use serialVersionUID from JDK 1.0.2 for interoperability */
+    private static final long serialVersionUID = -9172774392245257468L;
+}