|  | /* Double.java -- object wrapper for double | 
|  | Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 | 
|  | Free Software Foundation, Inc. | 
|  |  | 
|  | This file is part of GNU Classpath. | 
|  |  | 
|  | GNU Classpath is free software; you can redistribute it and/or modify | 
|  | it under the terms of the GNU General Public License as published by | 
|  | the Free Software Foundation; either version 2, or (at your option) | 
|  | any later version. | 
|  |  | 
|  | GNU Classpath 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 for more details. | 
|  |  | 
|  | You should have received a copy of the GNU General Public License | 
|  | along with GNU Classpath; see the file COPYING.  If not, write to the | 
|  | Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA | 
|  | 02110-1301 USA. | 
|  |  | 
|  | Linking this library statically or dynamically with other modules is | 
|  | making a combined work based on this library.  Thus, the terms and | 
|  | conditions of the GNU General Public License cover the whole | 
|  | combination. | 
|  |  | 
|  | As a special exception, the copyright holders of this library give you | 
|  | permission to link this library with independent modules to produce an | 
|  | executable, regardless of the license terms of these independent | 
|  | modules, and to copy and distribute the resulting executable under | 
|  | terms of your choice, provided that you also meet, for each linked | 
|  | independent module, the terms and conditions of the license of that | 
|  | module.  An independent module is a module which is not derived from | 
|  | or based on this library.  If you modify this library, you may extend | 
|  | this exception to your version of the library, but you are not | 
|  | obligated to do so.  If you do not wish to do so, delete this | 
|  | exception statement from your version. */ | 
|  |  | 
|  | package java.lang; | 
|  |  | 
|  | import gnu.java.lang.CPStringBuilder; | 
|  |  | 
|  | /** | 
|  | * Instances of class <code>Double</code> represent primitive | 
|  | * <code>double</code> values. | 
|  | * | 
|  | * Additionally, this class provides various helper functions and variables | 
|  | * related to doubles. | 
|  | * | 
|  | * @author Paul Fisher | 
|  | * @author Andrew Haley (aph@cygnus.com) | 
|  | * @author Eric Blake (ebb9@email.byu.edu) | 
|  | * @author Tom Tromey (tromey@redhat.com) | 
|  | * @author Andrew John Hughes (gnu_andrew@member.fsf.org) | 
|  | * @since 1.0 | 
|  | * @status partly updated to 1.5 | 
|  | */ | 
|  | public final class Double extends Number implements Comparable<Double> | 
|  | { | 
|  | /** | 
|  | * Compatible with JDK 1.0+. | 
|  | */ | 
|  | private static final long serialVersionUID = -9172774392245257468L; | 
|  |  | 
|  | /** | 
|  | * The maximum positive value a <code>double</code> may represent | 
|  | * is 1.7976931348623157e+308. | 
|  | */ | 
|  | public static final double MAX_VALUE = 1.7976931348623157e+308; | 
|  |  | 
|  | /** | 
|  | * The minimum positive value a <code>double</code> may represent | 
|  | * is 5e-324. | 
|  | */ | 
|  | public static final double MIN_VALUE = 5e-324; | 
|  |  | 
|  | /** | 
|  | * The value of a double representation -1.0/0.0, negative | 
|  | * infinity. | 
|  | */ | 
|  | public static final double NEGATIVE_INFINITY = -1.0 / 0.0; | 
|  |  | 
|  | /** | 
|  | * The value of a double representing 1.0/0.0, positive infinity. | 
|  | */ | 
|  | public static final double POSITIVE_INFINITY = 1.0 / 0.0; | 
|  |  | 
|  | /** | 
|  | * All IEEE 754 values of NaN have the same value in Java. | 
|  | */ | 
|  | public static final double NaN = 0.0 / 0.0; | 
|  |  | 
|  | /** | 
|  | * The number of bits needed to represent a <code>double</code>. | 
|  | * @since 1.5 | 
|  | */ | 
|  | public static final int SIZE = 64; | 
|  |  | 
|  | /** | 
|  | * The primitive type <code>double</code> is represented by this | 
|  | * <code>Class</code> object. | 
|  | * @since 1.1 | 
|  | */ | 
|  | public static final Class<Double> TYPE = (Class<Double>) VMClassLoader.getPrimitiveClass('D'); | 
|  |  | 
|  | /** | 
|  | * Cache representation of 0 | 
|  | */ | 
|  | private static final Double ZERO = new Double(0.0d); | 
|  |  | 
|  | /** | 
|  | * Cache representation of 1 | 
|  | */ | 
|  | private static final Double ONE = new Double(1.0d); | 
|  |  | 
|  | /** | 
|  | * The immutable value of this Double. | 
|  | * | 
|  | * @serial the wrapped double | 
|  | */ | 
|  | private final double value; | 
|  |  | 
|  | /** | 
|  | * Create a <code>Double</code> from the primitive <code>double</code> | 
|  | * specified. | 
|  | * | 
|  | * @param value the <code>double</code> argument | 
|  | */ | 
|  | public Double(double value) | 
|  | { | 
|  | this.value = value; | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Create a <code>Double</code> from the specified <code>String</code>. | 
|  | * This method calls <code>Double.parseDouble()</code>. | 
|  | * | 
|  | * @param s the <code>String</code> to convert | 
|  | * @throws NumberFormatException if <code>s</code> cannot be parsed as a | 
|  | *         <code>double</code> | 
|  | * @throws NullPointerException if <code>s</code> is null | 
|  | * @see #parseDouble(String) | 
|  | */ | 
|  | public Double(String s) | 
|  | { | 
|  | value = parseDouble(s); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Convert the <code>double</code> to a <code>String</code>. | 
|  | * Floating-point string representation is fairly complex: here is a | 
|  | * rundown of the possible values.  "<code>[-]</code>" indicates that a | 
|  | * negative sign will be printed if the value (or exponent) is negative. | 
|  | * "<code><number></code>" means a string of digits ('0' to '9'). | 
|  | * "<code><digit></code>" means a single digit ('0' to '9').<br> | 
|  | * | 
|  | * <table border=1> | 
|  | * <tr><th>Value of Double</th><th>String Representation</th></tr> | 
|  | * <tr><td>[+-] 0</td> <td><code>[-]0.0</code></td></tr> | 
|  | * <tr><td>Between [+-] 10<sup>-3</sup> and 10<sup>7</sup>, exclusive</td> | 
|  | *     <td><code>[-]number.number</code></td></tr> | 
|  | * <tr><td>Other numeric value</td> | 
|  | *     <td><code>[-]<digit>.<number> | 
|  | *          E[-]<number></code></td></tr> | 
|  | * <tr><td>[+-] infinity</td> <td><code>[-]Infinity</code></td></tr> | 
|  | * <tr><td>NaN</td> <td><code>NaN</code></td></tr> | 
|  | * </table> | 
|  | * | 
|  | * Yes, negative zero <em>is</em> a possible value.  Note that there is | 
|  | * <em>always</em> a <code>.</code> and at least one digit printed after | 
|  | * it: even if the number is 3, it will be printed as <code>3.0</code>. | 
|  | * After the ".", all digits will be printed except trailing zeros. The | 
|  | * result is rounded to the shortest decimal number which will parse back | 
|  | * to the same double. | 
|  | * | 
|  | * <p>To create other output formats, use {@link java.text.NumberFormat}. | 
|  | * | 
|  | * @XXX specify where we are not in accord with the spec. | 
|  | * | 
|  | * @param d the <code>double</code> to convert | 
|  | * @return the <code>String</code> representing the <code>double</code> | 
|  | */ | 
|  | public static String toString(double d) | 
|  | { | 
|  | return VMDouble.toString(d, false); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Convert a double value to a hexadecimal string.  This converts as | 
|  | * follows: | 
|  | * <ul> | 
|  | * <li> A NaN value is converted to the string "NaN". | 
|  | * <li> Positive infinity is converted to the string "Infinity". | 
|  | * <li> Negative infinity is converted to the string "-Infinity". | 
|  | * <li> For all other values, the first character of the result is '-' | 
|  | * if the value is negative.  This is followed by '0x1.' if the | 
|  | * value is normal, and '0x0.' if the value is denormal.  This is | 
|  | * then followed by a (lower-case) hexadecimal representation of the | 
|  | * mantissa, with leading zeros as required for denormal values. | 
|  | * The next character is a 'p', and this is followed by a decimal | 
|  | * representation of the unbiased exponent. | 
|  | * </ul> | 
|  | * @param d the double value | 
|  | * @return the hexadecimal string representation | 
|  | * @since 1.5 | 
|  | */ | 
|  | public static String toHexString(double d) | 
|  | { | 
|  | if (isNaN(d)) | 
|  | return "NaN"; | 
|  | if (isInfinite(d)) | 
|  | return d < 0 ? "-Infinity" : "Infinity"; | 
|  |  | 
|  | long bits = doubleToLongBits(d); | 
|  | CPStringBuilder result = new CPStringBuilder(); | 
|  |  | 
|  | if (bits < 0) | 
|  | result.append('-'); | 
|  | result.append("0x"); | 
|  |  | 
|  | final int mantissaBits = 52; | 
|  | final int exponentBits = 11; | 
|  | long mantMask = (1L << mantissaBits) - 1; | 
|  | long mantissa = bits & mantMask; | 
|  | long expMask = (1L << exponentBits) - 1; | 
|  | long exponent = (bits >>> mantissaBits) & expMask; | 
|  |  | 
|  | result.append(exponent == 0 ? '0' : '1'); | 
|  | result.append('.'); | 
|  | result.append(Long.toHexString(mantissa)); | 
|  | if (exponent == 0 && mantissa != 0) | 
|  | { | 
|  | // Treat denormal specially by inserting '0's to make | 
|  | // the length come out right.  The constants here are | 
|  | // to account for things like the '0x'. | 
|  | int offset = 4 + ((bits < 0) ? 1 : 0); | 
|  | // The silly +3 is here to keep the code the same between | 
|  | // the Float and Double cases.  In Float the value is | 
|  | // not a multiple of 4. | 
|  | int desiredLength = offset + (mantissaBits + 3) / 4; | 
|  | while (result.length() < desiredLength) | 
|  | result.insert(offset, '0'); | 
|  | } | 
|  | result.append('p'); | 
|  | if (exponent == 0 && mantissa == 0) | 
|  | { | 
|  | // Zero, so do nothing special. | 
|  | } | 
|  | else | 
|  | { | 
|  | // Apply bias. | 
|  | boolean denormal = exponent == 0; | 
|  | exponent -= (1 << (exponentBits - 1)) - 1; | 
|  | // Handle denormal. | 
|  | if (denormal) | 
|  | ++exponent; | 
|  | } | 
|  |  | 
|  | result.append(Long.toString(exponent)); | 
|  | return result.toString(); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Returns a <code>Double</code> object wrapping the value. | 
|  | * In contrast to the <code>Double</code> constructor, this method | 
|  | * may cache some values.  It is used by boxing conversion. | 
|  | * | 
|  | * @param val the value to wrap | 
|  | * @return the <code>Double</code> | 
|  | * @since 1.5 | 
|  | */ | 
|  | public static Double valueOf(double val) | 
|  | { | 
|  | if ((val == 0.0) && (doubleToRawLongBits(val) == 0L)) | 
|  | return ZERO; | 
|  | else if (val == 1.0) | 
|  | return ONE; | 
|  | else | 
|  | return new Double(val); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Create a new <code>Double</code> object using the <code>String</code>. | 
|  | * | 
|  | * @param s the <code>String</code> to convert | 
|  | * @return the new <code>Double</code> | 
|  | * @throws NumberFormatException if <code>s</code> cannot be parsed as a | 
|  | *         <code>double</code> | 
|  | * @throws NullPointerException if <code>s</code> is null. | 
|  | * @see #parseDouble(String) | 
|  | */ | 
|  | public static Double valueOf(String s) | 
|  | { | 
|  | return valueOf(parseDouble(s)); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Parse the specified <code>String</code> as a <code>double</code>. The | 
|  | * extended BNF grammar is as follows:<br> | 
|  | * <pre> | 
|  | * <em>DecodableString</em>: | 
|  | *      ( [ <code>-</code> | <code>+</code> ] <code>NaN</code> ) | 
|  | *    | ( [ <code>-</code> | <code>+</code> ] <code>Infinity</code> ) | 
|  | *    | ( [ <code>-</code> | <code>+</code> ] <em>FloatingPoint</em> | 
|  | *              [ <code>f</code> | <code>F</code> | <code>d</code> | 
|  | *                | <code>D</code>] ) | 
|  | * <em>FloatingPoint</em>: | 
|  | *      ( { <em>Digit</em> }+ [ <code>.</code> { <em>Digit</em> } ] | 
|  | *              [ <em>Exponent</em> ] ) | 
|  | *    | ( <code>.</code> { <em>Digit</em> }+ [ <em>Exponent</em> ] ) | 
|  | * <em>Exponent</em>: | 
|  | *      ( ( <code>e</code> | <code>E</code> ) | 
|  | *              [ <code>-</code> | <code>+</code> ] { <em>Digit</em> }+ ) | 
|  | * <em>Digit</em>: <em><code>'0'</code> through <code>'9'</code></em> | 
|  | * </pre> | 
|  | * | 
|  | * <p>NaN and infinity are special cases, to allow parsing of the output | 
|  | * of toString.  Otherwise, the result is determined by calculating | 
|  | * <em>n * 10<sup>exponent</sup></em> to infinite precision, then rounding | 
|  | * to the nearest double. Remember that many numbers cannot be precisely | 
|  | * represented in floating point. In case of overflow, infinity is used, | 
|  | * and in case of underflow, signed zero is used. Unlike Integer.parseInt, | 
|  | * this does not accept Unicode digits outside the ASCII range. | 
|  | * | 
|  | * <p>If an unexpected character is found in the <code>String</code>, a | 
|  | * <code>NumberFormatException</code> will be thrown.  Leading and trailing | 
|  | * 'whitespace' is ignored via <code>String.trim()</code>, but spaces | 
|  | * internal to the actual number are not allowed. | 
|  | * | 
|  | * <p>To parse numbers according to another format, consider using | 
|  | * {@link java.text.NumberFormat}. | 
|  | * | 
|  | * @XXX specify where/how we are not in accord with the spec. | 
|  | * | 
|  | * @param str the <code>String</code> to convert | 
|  | * @return the <code>double</code> value of <code>s</code> | 
|  | * @throws NumberFormatException if <code>s</code> cannot be parsed as a | 
|  | *         <code>double</code> | 
|  | * @throws NullPointerException if <code>s</code> is null | 
|  | * @see #MIN_VALUE | 
|  | * @see #MAX_VALUE | 
|  | * @see #POSITIVE_INFINITY | 
|  | * @see #NEGATIVE_INFINITY | 
|  | * @since 1.2 | 
|  | */ | 
|  | public static double parseDouble(String str) | 
|  | { | 
|  | return VMDouble.parseDouble(str); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Return <code>true</code> if the <code>double</code> has the same | 
|  | * value as <code>NaN</code>, otherwise return <code>false</code>. | 
|  | * | 
|  | * @param v the <code>double</code> to compare | 
|  | * @return whether the argument is <code>NaN</code>. | 
|  | */ | 
|  | public static boolean isNaN(double v) | 
|  | { | 
|  | // This works since NaN != NaN is the only reflexive inequality | 
|  | // comparison which returns true. | 
|  | return v != v; | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Return <code>true</code> if the <code>double</code> has a value | 
|  | * equal to either <code>NEGATIVE_INFINITY</code> or | 
|  | * <code>POSITIVE_INFINITY</code>, otherwise return <code>false</code>. | 
|  | * | 
|  | * @param v the <code>double</code> to compare | 
|  | * @return whether the argument is (-/+) infinity. | 
|  | */ | 
|  | public static boolean isInfinite(double v) | 
|  | { | 
|  | return v == POSITIVE_INFINITY || v == NEGATIVE_INFINITY; | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Return <code>true</code> if the value of this <code>Double</code> | 
|  | * is the same as <code>NaN</code>, otherwise return <code>false</code>. | 
|  | * | 
|  | * @return whether this <code>Double</code> is <code>NaN</code> | 
|  | */ | 
|  | public boolean isNaN() | 
|  | { | 
|  | return isNaN(value); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Return <code>true</code> if the value of this <code>Double</code> | 
|  | * is the same as <code>NEGATIVE_INFINITY</code> or | 
|  | * <code>POSITIVE_INFINITY</code>, otherwise return <code>false</code>. | 
|  | * | 
|  | * @return whether this <code>Double</code> is (-/+) infinity | 
|  | */ | 
|  | public boolean isInfinite() | 
|  | { | 
|  | return isInfinite(value); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Convert the <code>double</code> value of this <code>Double</code> | 
|  | * to a <code>String</code>.  This method calls | 
|  | * <code>Double.toString(double)</code> to do its dirty work. | 
|  | * | 
|  | * @return the <code>String</code> representation | 
|  | * @see #toString(double) | 
|  | */ | 
|  | public String toString() | 
|  | { | 
|  | return toString(value); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Return the value of this <code>Double</code> as a <code>byte</code>. | 
|  | * | 
|  | * @return the byte value | 
|  | * @since 1.1 | 
|  | */ | 
|  | public byte byteValue() | 
|  | { | 
|  | return (byte) value; | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Return the value of this <code>Double</code> as a <code>short</code>. | 
|  | * | 
|  | * @return the short value | 
|  | * @since 1.1 | 
|  | */ | 
|  | public short shortValue() | 
|  | { | 
|  | return (short) value; | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Return the value of this <code>Double</code> as an <code>int</code>. | 
|  | * | 
|  | * @return the int value | 
|  | */ | 
|  | public int intValue() | 
|  | { | 
|  | return (int) value; | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Return the value of this <code>Double</code> as a <code>long</code>. | 
|  | * | 
|  | * @return the long value | 
|  | */ | 
|  | public long longValue() | 
|  | { | 
|  | return (long) value; | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Return the value of this <code>Double</code> as a <code>float</code>. | 
|  | * | 
|  | * @return the float value | 
|  | */ | 
|  | public float floatValue() | 
|  | { | 
|  | return (float) value; | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Return the value of this <code>Double</code>. | 
|  | * | 
|  | * @return the double value | 
|  | */ | 
|  | public double doubleValue() | 
|  | { | 
|  | return value; | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Return a hashcode representing this Object. <code>Double</code>'s hash | 
|  | * code is calculated by:<br> | 
|  | * <code>long v = Double.doubleToLongBits(doubleValue());<br> | 
|  | *    int hash = (int)(v^(v>>32))</code>. | 
|  | * | 
|  | * @return this Object's hash code | 
|  | * @see #doubleToLongBits(double) | 
|  | */ | 
|  | public int hashCode() | 
|  | { | 
|  | long v = doubleToLongBits(value); | 
|  | return (int) (v ^ (v >>> 32)); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Returns <code>true</code> if <code>obj</code> is an instance of | 
|  | * <code>Double</code> and represents the same double value. Unlike comparing | 
|  | * two doubles with <code>==</code>, this treats two instances of | 
|  | * <code>Double.NaN</code> as equal, but treats <code>0.0</code> and | 
|  | * <code>-0.0</code> as unequal. | 
|  | * | 
|  | * <p>Note that <code>d1.equals(d2)</code> is identical to | 
|  | * <code>doubleToLongBits(d1.doubleValue()) == | 
|  | *    doubleToLongBits(d2.doubleValue())</code>. | 
|  | * | 
|  | * @param obj the object to compare | 
|  | * @return whether the objects are semantically equal | 
|  | */ | 
|  | public boolean equals(Object obj) | 
|  | { | 
|  | if (obj instanceof Double) | 
|  | { | 
|  | double d = ((Double) obj).value; | 
|  | return (doubleToRawLongBits(value) == doubleToRawLongBits(d)) || | 
|  | (isNaN(value) && isNaN(d)); | 
|  | } | 
|  | return false; | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Convert the double to the IEEE 754 floating-point "double format" bit | 
|  | * layout. Bit 63 (the most significant) is the sign bit, bits 62-52 | 
|  | * (masked by 0x7ff0000000000000L) represent the exponent, and bits 51-0 | 
|  | * (masked by 0x000fffffffffffffL) are the mantissa. This function | 
|  | * collapses all versions of NaN to 0x7ff8000000000000L. The result of this | 
|  | * function can be used as the argument to | 
|  | * <code>Double.longBitsToDouble(long)</code> to obtain the original | 
|  | * <code>double</code> value. | 
|  | * | 
|  | * @param value the <code>double</code> to convert | 
|  | * @return the bits of the <code>double</code> | 
|  | * @see #longBitsToDouble(long) | 
|  | */ | 
|  | public static long doubleToLongBits(double value) | 
|  | { | 
|  | if (isNaN(value)) | 
|  | return 0x7ff8000000000000L; | 
|  | else | 
|  | return VMDouble.doubleToRawLongBits(value); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Convert the double to the IEEE 754 floating-point "double format" bit | 
|  | * layout. Bit 63 (the most significant) is the sign bit, bits 62-52 | 
|  | * (masked by 0x7ff0000000000000L) represent the exponent, and bits 51-0 | 
|  | * (masked by 0x000fffffffffffffL) are the mantissa. This function | 
|  | * leaves NaN alone, rather than collapsing to a canonical value. The | 
|  | * result of this function can be used as the argument to | 
|  | * <code>Double.longBitsToDouble(long)</code> to obtain the original | 
|  | * <code>double</code> value. | 
|  | * | 
|  | * @param value the <code>double</code> to convert | 
|  | * @return the bits of the <code>double</code> | 
|  | * @see #longBitsToDouble(long) | 
|  | */ | 
|  | public static long doubleToRawLongBits(double value) | 
|  | { | 
|  | return VMDouble.doubleToRawLongBits(value); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Convert the argument in IEEE 754 floating-point "double format" bit | 
|  | * layout to the corresponding float. Bit 63 (the most significant) is the | 
|  | * sign bit, bits 62-52 (masked by 0x7ff0000000000000L) represent the | 
|  | * exponent, and bits 51-0 (masked by 0x000fffffffffffffL) are the mantissa. | 
|  | * This function leaves NaN alone, so that you can recover the bit pattern | 
|  | * with <code>Double.doubleToRawLongBits(double)</code>. | 
|  | * | 
|  | * @param bits the bits to convert | 
|  | * @return the <code>double</code> represented by the bits | 
|  | * @see #doubleToLongBits(double) | 
|  | * @see #doubleToRawLongBits(double) | 
|  | */ | 
|  | public static double longBitsToDouble(long bits) | 
|  | { | 
|  | return VMDouble.longBitsToDouble(bits); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Compare two Doubles numerically by comparing their <code>double</code> | 
|  | * values. The result is positive if the first is greater, negative if the | 
|  | * second is greater, and 0 if the two are equal. However, this special | 
|  | * cases NaN and signed zero as follows: NaN is considered greater than | 
|  | * all other doubles, including <code>POSITIVE_INFINITY</code>, and positive | 
|  | * zero is considered greater than negative zero. | 
|  | * | 
|  | * @param d the Double to compare | 
|  | * @return the comparison | 
|  | * @since 1.2 | 
|  | */ | 
|  | public int compareTo(Double d) | 
|  | { | 
|  | return compare(value, d.value); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Behaves like <code>new Double(x).compareTo(new Double(y))</code>; in | 
|  | * other words this compares two doubles, special casing NaN and zero, | 
|  | * without the overhead of objects. | 
|  | * | 
|  | * @param x the first double to compare | 
|  | * @param y the second double to compare | 
|  | * @return the comparison | 
|  | * @since 1.4 | 
|  | */ | 
|  | public static int compare(double x, double y) | 
|  | { | 
|  | // handle the easy cases: | 
|  | if (x < y) | 
|  | return -1; | 
|  | if (x > y) | 
|  | return 1; | 
|  |  | 
|  | // handle equality respecting that 0.0 != -0.0 (hence not using x == y): | 
|  | long lx = doubleToRawLongBits(x); | 
|  | long ly = doubleToRawLongBits(y); | 
|  | if (lx == ly) | 
|  | return 0; | 
|  |  | 
|  | // handle NaNs: | 
|  | if (x != x) | 
|  | return (y != y) ? 0 : 1; | 
|  | else if (y != y) | 
|  | return -1; | 
|  |  | 
|  | // handle +/- 0.0 | 
|  | return (lx < ly) ? -1 : 1; | 
|  | } | 
|  | } |