emul/src/main/java/java/lang/Math.java
author Jaroslav Tulach <jtulach@netbeans.org>
Tue, 30 Oct 2012 23:33:29 +0100
changeset 132 2377bb30dd1b
parent 104 1376481f15e7
child 551 ca781bc82662
permissions -rw-r--r--
Removing StrictMath
     1 /*
     2  * Copyright (c) 1994, 2011, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.  Oracle designates this
     8  * particular file as subject to the "Classpath" exception as provided
     9  * by Oracle in the LICENSE file that accompanied this code.
    10  *
    11  * This code is distributed in the hope that it will be useful, but WITHOUT
    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    14  * version 2 for more details (a copy is included in the LICENSE file that
    15  * accompanied this code).
    16  *
    17  * You should have received a copy of the GNU General Public License version
    18  * 2 along with this work; if not, write to the Free Software Foundation,
    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    20  *
    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    22  * or visit www.oracle.com if you need additional information or have any
    23  * questions.
    24  */
    25 
    26 package java.lang;
    27 
    28 import org.apidesign.bck2brwsr.core.JavaScriptBody;
    29 
    30 
    31 /**
    32  * The class {@code Math} contains methods for performing basic
    33  * numeric operations such as the elementary exponential, logarithm,
    34  * square root, and trigonometric functions.
    35  *
    36  * <p>Unlike some of the numeric methods of class
    37  * {@code StrictMath}, all implementations of the equivalent
    38  * functions of class {@code Math} are not defined to return the
    39  * bit-for-bit same results.  This relaxation permits
    40  * better-performing implementations where strict reproducibility is
    41  * not required.
    42  *
    43  * <p>By default many of the {@code Math} methods simply call
    44  * the equivalent method in {@code StrictMath} for their
    45  * implementation.  Code generators are encouraged to use
    46  * platform-specific native libraries or microprocessor instructions,
    47  * where available, to provide higher-performance implementations of
    48  * {@code Math} methods.  Such higher-performance
    49  * implementations still must conform to the specification for
    50  * {@code Math}.
    51  *
    52  * <p>The quality of implementation specifications concern two
    53  * properties, accuracy of the returned result and monotonicity of the
    54  * method.  Accuracy of the floating-point {@code Math} methods
    55  * is measured in terms of <i>ulps</i>, units in the last place.  For
    56  * a given floating-point format, an ulp of a specific real number
    57  * value is the distance between the two floating-point values
    58  * bracketing that numerical value.  When discussing the accuracy of a
    59  * method as a whole rather than at a specific argument, the number of
    60  * ulps cited is for the worst-case error at any argument.  If a
    61  * method always has an error less than 0.5 ulps, the method always
    62  * returns the floating-point number nearest the exact result; such a
    63  * method is <i>correctly rounded</i>.  A correctly rounded method is
    64  * generally the best a floating-point approximation can be; however,
    65  * it is impractical for many floating-point methods to be correctly
    66  * rounded.  Instead, for the {@code Math} class, a larger error
    67  * bound of 1 or 2 ulps is allowed for certain methods.  Informally,
    68  * with a 1 ulp error bound, when the exact result is a representable
    69  * number, the exact result should be returned as the computed result;
    70  * otherwise, either of the two floating-point values which bracket
    71  * the exact result may be returned.  For exact results large in
    72  * magnitude, one of the endpoints of the bracket may be infinite.
    73  * Besides accuracy at individual arguments, maintaining proper
    74  * relations between the method at different arguments is also
    75  * important.  Therefore, most methods with more than 0.5 ulp errors
    76  * are required to be <i>semi-monotonic</i>: whenever the mathematical
    77  * function is non-decreasing, so is the floating-point approximation,
    78  * likewise, whenever the mathematical function is non-increasing, so
    79  * is the floating-point approximation.  Not all approximations that
    80  * have 1 ulp accuracy will automatically meet the monotonicity
    81  * requirements.
    82  *
    83  * @author  unascribed
    84  * @author  Joseph D. Darcy
    85  * @since   JDK1.0
    86  */
    87 
    88 public final class Math {
    89 
    90     /**
    91      * Don't let anyone instantiate this class.
    92      */
    93     private Math() {}
    94 
    95     /**
    96      * The {@code double} value that is closer than any other to
    97      * <i>e</i>, the base of the natural logarithms.
    98      */
    99     public static final double E = 2.7182818284590452354;
   100 
   101     /**
   102      * The {@code double} value that is closer than any other to
   103      * <i>pi</i>, the ratio of the circumference of a circle to its
   104      * diameter.
   105      */
   106     public static final double PI = 3.14159265358979323846;
   107 
   108     /**
   109      * Returns the trigonometric sine of an angle.  Special cases:
   110      * <ul><li>If the argument is NaN or an infinity, then the
   111      * result is NaN.
   112      * <li>If the argument is zero, then the result is a zero with the
   113      * same sign as the argument.</ul>
   114      *
   115      * <p>The computed result must be within 1 ulp of the exact result.
   116      * Results must be semi-monotonic.
   117      *
   118      * @param   a   an angle, in radians.
   119      * @return  the sine of the argument.
   120      */
   121     @JavaScriptBody(args="a", body="return Math.sin(a);")
   122     public static double sin(double a) {
   123         throw new UnsupportedOperationException();
   124     }
   125 
   126     /**
   127      * Returns the trigonometric cosine of an angle. Special cases:
   128      * <ul><li>If the argument is NaN or an infinity, then the
   129      * result is NaN.</ul>
   130      *
   131      * <p>The computed result must be within 1 ulp of the exact result.
   132      * Results must be semi-monotonic.
   133      *
   134      * @param   a   an angle, in radians.
   135      * @return  the cosine of the argument.
   136      */
   137     @JavaScriptBody(args="a", body="return Math.cos(a);")
   138     public static double cos(double a) {
   139         throw new UnsupportedOperationException();
   140     }
   141 
   142     /**
   143      * Returns the trigonometric tangent of an angle.  Special cases:
   144      * <ul><li>If the argument is NaN or an infinity, then the result
   145      * is NaN.
   146      * <li>If the argument is zero, then the result is a zero with the
   147      * same sign as the argument.</ul>
   148      *
   149      * <p>The computed result must be within 1 ulp of the exact result.
   150      * Results must be semi-monotonic.
   151      *
   152      * @param   a   an angle, in radians.
   153      * @return  the tangent of the argument.
   154      */
   155     @JavaScriptBody(args="a", body="return Math.tan(a);")
   156     public static double tan(double a) {
   157         throw new UnsupportedOperationException();
   158     }
   159 
   160     /**
   161      * Returns the arc sine of a value; the returned angle is in the
   162      * range -<i>pi</i>/2 through <i>pi</i>/2.  Special cases:
   163      * <ul><li>If the argument is NaN or its absolute value is greater
   164      * than 1, then the result is NaN.
   165      * <li>If the argument is zero, then the result is a zero with the
   166      * same sign as the argument.</ul>
   167      *
   168      * <p>The computed result must be within 1 ulp of the exact result.
   169      * Results must be semi-monotonic.
   170      *
   171      * @param   a   the value whose arc sine is to be returned.
   172      * @return  the arc sine of the argument.
   173      */
   174     @JavaScriptBody(args="a", body="return Math.asin(a);")
   175     public static double asin(double a) {
   176         throw new UnsupportedOperationException();
   177     }
   178 
   179     /**
   180      * Returns the arc cosine of a value; the returned angle is in the
   181      * range 0.0 through <i>pi</i>.  Special case:
   182      * <ul><li>If the argument is NaN or its absolute value is greater
   183      * than 1, then the result is NaN.</ul>
   184      *
   185      * <p>The computed result must be within 1 ulp of the exact result.
   186      * Results must be semi-monotonic.
   187      *
   188      * @param   a   the value whose arc cosine is to be returned.
   189      * @return  the arc cosine of the argument.
   190      */
   191     @JavaScriptBody(args="a", body="return Math.acos(a);")
   192     public static double acos(double a) {
   193         throw new UnsupportedOperationException();
   194     }
   195 
   196     /**
   197      * Returns the arc tangent of a value; the returned angle is in the
   198      * range -<i>pi</i>/2 through <i>pi</i>/2.  Special cases:
   199      * <ul><li>If the argument is NaN, then the result is NaN.
   200      * <li>If the argument is zero, then the result is a zero with the
   201      * same sign as the argument.</ul>
   202      *
   203      * <p>The computed result must be within 1 ulp of the exact result.
   204      * Results must be semi-monotonic.
   205      *
   206      * @param   a   the value whose arc tangent is to be returned.
   207      * @return  the arc tangent of the argument.
   208      */
   209     @JavaScriptBody(args="a", body="return Math.atan(a);")
   210     public static double atan(double a) {
   211         throw new UnsupportedOperationException();
   212     }
   213 
   214     /**
   215      * Converts an angle measured in degrees to an approximately
   216      * equivalent angle measured in radians.  The conversion from
   217      * degrees to radians is generally inexact.
   218      *
   219      * @param   angdeg   an angle, in degrees
   220      * @return  the measurement of the angle {@code angdeg}
   221      *          in radians.
   222      * @since   1.2
   223      */
   224     public static double toRadians(double angdeg) {
   225         return angdeg / 180.0 * PI;
   226     }
   227 
   228     /**
   229      * Converts an angle measured in radians to an approximately
   230      * equivalent angle measured in degrees.  The conversion from
   231      * radians to degrees is generally inexact; users should
   232      * <i>not</i> expect {@code cos(toRadians(90.0))} to exactly
   233      * equal {@code 0.0}.
   234      *
   235      * @param   angrad   an angle, in radians
   236      * @return  the measurement of the angle {@code angrad}
   237      *          in degrees.
   238      * @since   1.2
   239      */
   240     public static double toDegrees(double angrad) {
   241         return angrad * 180.0 / PI;
   242     }
   243 
   244     /**
   245      * Returns Euler's number <i>e</i> raised to the power of a
   246      * {@code double} value.  Special cases:
   247      * <ul><li>If the argument is NaN, the result is NaN.
   248      * <li>If the argument is positive infinity, then the result is
   249      * positive infinity.
   250      * <li>If the argument is negative infinity, then the result is
   251      * positive zero.</ul>
   252      *
   253      * <p>The computed result must be within 1 ulp of the exact result.
   254      * Results must be semi-monotonic.
   255      *
   256      * @param   a   the exponent to raise <i>e</i> to.
   257      * @return  the value <i>e</i><sup>{@code a}</sup>,
   258      *          where <i>e</i> is the base of the natural logarithms.
   259      */
   260     @JavaScriptBody(args="a", body="return Math.exp(a);")
   261     public static double exp(double a) {
   262         throw new UnsupportedOperationException();
   263     }
   264 
   265     /**
   266      * Returns the natural logarithm (base <i>e</i>) of a {@code double}
   267      * value.  Special cases:
   268      * <ul><li>If the argument is NaN or less than zero, then the result
   269      * is NaN.
   270      * <li>If the argument is positive infinity, then the result is
   271      * positive infinity.
   272      * <li>If the argument is positive zero or negative zero, then the
   273      * result is negative infinity.</ul>
   274      *
   275      * <p>The computed result must be within 1 ulp of the exact result.
   276      * Results must be semi-monotonic.
   277      *
   278      * @param   a   a value
   279      * @return  the value ln&nbsp;{@code a}, the natural logarithm of
   280      *          {@code a}.
   281      */
   282     @JavaScriptBody(args="a", body="return Math.log(a);")
   283     public static double log(double a) {
   284         throw new UnsupportedOperationException();
   285     }
   286 
   287     /**
   288      * Returns the base 10 logarithm of a {@code double} value.
   289      * Special cases:
   290      *
   291      * <ul><li>If the argument is NaN or less than zero, then the result
   292      * is NaN.
   293      * <li>If the argument is positive infinity, then the result is
   294      * positive infinity.
   295      * <li>If the argument is positive zero or negative zero, then the
   296      * result is negative infinity.
   297      * <li> If the argument is equal to 10<sup><i>n</i></sup> for
   298      * integer <i>n</i>, then the result is <i>n</i>.
   299      * </ul>
   300      *
   301      * <p>The computed result must be within 1 ulp of the exact result.
   302      * Results must be semi-monotonic.
   303      *
   304      * @param   a   a value
   305      * @return  the base 10 logarithm of  {@code a}.
   306      * @since 1.5
   307      */
   308     @JavaScriptBody(args="a", body="return Math.log(a) / Math.LN10;")
   309     public static double log10(double a) {
   310         throw new UnsupportedOperationException();
   311     }
   312 
   313     /**
   314      * Returns the correctly rounded positive square root of a
   315      * {@code double} value.
   316      * Special cases:
   317      * <ul><li>If the argument is NaN or less than zero, then the result
   318      * is NaN.
   319      * <li>If the argument is positive infinity, then the result is positive
   320      * infinity.
   321      * <li>If the argument is positive zero or negative zero, then the
   322      * result is the same as the argument.</ul>
   323      * Otherwise, the result is the {@code double} value closest to
   324      * the true mathematical square root of the argument value.
   325      *
   326      * @param   a   a value.
   327      * @return  the positive square root of {@code a}.
   328      *          If the argument is NaN or less than zero, the result is NaN.
   329      */
   330     @JavaScriptBody(args="a", body="return Math.sqrt(a);")
   331     public static double sqrt(double a) {
   332         throw new UnsupportedOperationException();
   333     }
   334 
   335     /**
   336      * Returns the smallest (closest to negative infinity)
   337      * {@code double} value that is greater than or equal to the
   338      * argument and is equal to a mathematical integer. Special cases:
   339      * <ul><li>If the argument value is already equal to a
   340      * mathematical integer, then the result is the same as the
   341      * argument.  <li>If the argument is NaN or an infinity or
   342      * positive zero or negative zero, then the result is the same as
   343      * the argument.  <li>If the argument value is less than zero but
   344      * greater than -1.0, then the result is negative zero.</ul> Note
   345      * that the value of {@code Math.ceil(x)} is exactly the
   346      * value of {@code -Math.floor(-x)}.
   347      *
   348      *
   349      * @param   a   a value.
   350      * @return  the smallest (closest to negative infinity)
   351      *          floating-point value that is greater than or equal to
   352      *          the argument and is equal to a mathematical integer.
   353      */
   354     @JavaScriptBody(args="a", body="return Math.ceil(a);")
   355     public static double ceil(double a) {
   356         throw new UnsupportedOperationException();
   357     }
   358 
   359     /**
   360      * Returns the largest (closest to positive infinity)
   361      * {@code double} value that is less than or equal to the
   362      * argument and is equal to a mathematical integer. Special cases:
   363      * <ul><li>If the argument value is already equal to a
   364      * mathematical integer, then the result is the same as the
   365      * argument.  <li>If the argument is NaN or an infinity or
   366      * positive zero or negative zero, then the result is the same as
   367      * the argument.</ul>
   368      *
   369      * @param   a   a value.
   370      * @return  the largest (closest to positive infinity)
   371      *          floating-point value that less than or equal to the argument
   372      *          and is equal to a mathematical integer.
   373      */
   374     @JavaScriptBody(args="a", body="return Math.floor(a);")
   375     public static double floor(double a) {
   376         throw new UnsupportedOperationException();
   377     }
   378 
   379     /**
   380      * Returns the angle <i>theta</i> from the conversion of rectangular
   381      * coordinates ({@code x},&nbsp;{@code y}) to polar
   382      * coordinates (r,&nbsp;<i>theta</i>).
   383      * This method computes the phase <i>theta</i> by computing an arc tangent
   384      * of {@code y/x} in the range of -<i>pi</i> to <i>pi</i>. Special
   385      * cases:
   386      * <ul><li>If either argument is NaN, then the result is NaN.
   387      * <li>If the first argument is positive zero and the second argument
   388      * is positive, or the first argument is positive and finite and the
   389      * second argument is positive infinity, then the result is positive
   390      * zero.
   391      * <li>If the first argument is negative zero and the second argument
   392      * is positive, or the first argument is negative and finite and the
   393      * second argument is positive infinity, then the result is negative zero.
   394      * <li>If the first argument is positive zero and the second argument
   395      * is negative, or the first argument is positive and finite and the
   396      * second argument is negative infinity, then the result is the
   397      * {@code double} value closest to <i>pi</i>.
   398      * <li>If the first argument is negative zero and the second argument
   399      * is negative, or the first argument is negative and finite and the
   400      * second argument is negative infinity, then the result is the
   401      * {@code double} value closest to -<i>pi</i>.
   402      * <li>If the first argument is positive and the second argument is
   403      * positive zero or negative zero, or the first argument is positive
   404      * infinity and the second argument is finite, then the result is the
   405      * {@code double} value closest to <i>pi</i>/2.
   406      * <li>If the first argument is negative and the second argument is
   407      * positive zero or negative zero, or the first argument is negative
   408      * infinity and the second argument is finite, then the result is the
   409      * {@code double} value closest to -<i>pi</i>/2.
   410      * <li>If both arguments are positive infinity, then the result is the
   411      * {@code double} value closest to <i>pi</i>/4.
   412      * <li>If the first argument is positive infinity and the second argument
   413      * is negative infinity, then the result is the {@code double}
   414      * value closest to 3*<i>pi</i>/4.
   415      * <li>If the first argument is negative infinity and the second argument
   416      * is positive infinity, then the result is the {@code double} value
   417      * closest to -<i>pi</i>/4.
   418      * <li>If both arguments are negative infinity, then the result is the
   419      * {@code double} value closest to -3*<i>pi</i>/4.</ul>
   420      *
   421      * <p>The computed result must be within 2 ulps of the exact result.
   422      * Results must be semi-monotonic.
   423      *
   424      * @param   y   the ordinate coordinate
   425      * @param   x   the abscissa coordinate
   426      * @return  the <i>theta</i> component of the point
   427      *          (<i>r</i>,&nbsp;<i>theta</i>)
   428      *          in polar coordinates that corresponds to the point
   429      *          (<i>x</i>,&nbsp;<i>y</i>) in Cartesian coordinates.
   430      */
   431     @JavaScriptBody(args={"y", "x"}, body="return Math.atan2(y, x);")
   432     public static double atan2(double y, double x) {
   433         throw new UnsupportedOperationException();
   434     }
   435 
   436     /**
   437      * Returns the value of the first argument raised to the power of the
   438      * second argument. Special cases:
   439      *
   440      * <ul><li>If the second argument is positive or negative zero, then the
   441      * result is 1.0.
   442      * <li>If the second argument is 1.0, then the result is the same as the
   443      * first argument.
   444      * <li>If the second argument is NaN, then the result is NaN.
   445      * <li>If the first argument is NaN and the second argument is nonzero,
   446      * then the result is NaN.
   447      *
   448      * <li>If
   449      * <ul>
   450      * <li>the absolute value of the first argument is greater than 1
   451      * and the second argument is positive infinity, or
   452      * <li>the absolute value of the first argument is less than 1 and
   453      * the second argument is negative infinity,
   454      * </ul>
   455      * then the result is positive infinity.
   456      *
   457      * <li>If
   458      * <ul>
   459      * <li>the absolute value of the first argument is greater than 1 and
   460      * the second argument is negative infinity, or
   461      * <li>the absolute value of the
   462      * first argument is less than 1 and the second argument is positive
   463      * infinity,
   464      * </ul>
   465      * then the result is positive zero.
   466      *
   467      * <li>If the absolute value of the first argument equals 1 and the
   468      * second argument is infinite, then the result is NaN.
   469      *
   470      * <li>If
   471      * <ul>
   472      * <li>the first argument is positive zero and the second argument
   473      * is greater than zero, or
   474      * <li>the first argument is positive infinity and the second
   475      * argument is less than zero,
   476      * </ul>
   477      * then the result is positive zero.
   478      *
   479      * <li>If
   480      * <ul>
   481      * <li>the first argument is positive zero and the second argument
   482      * is less than zero, or
   483      * <li>the first argument is positive infinity and the second
   484      * argument is greater than zero,
   485      * </ul>
   486      * then the result is positive infinity.
   487      *
   488      * <li>If
   489      * <ul>
   490      * <li>the first argument is negative zero and the second argument
   491      * is greater than zero but not a finite odd integer, or
   492      * <li>the first argument is negative infinity and the second
   493      * argument is less than zero but not a finite odd integer,
   494      * </ul>
   495      * then the result is positive zero.
   496      *
   497      * <li>If
   498      * <ul>
   499      * <li>the first argument is negative zero and the second argument
   500      * is a positive finite odd integer, or
   501      * <li>the first argument is negative infinity and the second
   502      * argument is a negative finite odd integer,
   503      * </ul>
   504      * then the result is negative zero.
   505      *
   506      * <li>If
   507      * <ul>
   508      * <li>the first argument is negative zero and the second argument
   509      * is less than zero but not a finite odd integer, or
   510      * <li>the first argument is negative infinity and the second
   511      * argument is greater than zero but not a finite odd integer,
   512      * </ul>
   513      * then the result is positive infinity.
   514      *
   515      * <li>If
   516      * <ul>
   517      * <li>the first argument is negative zero and the second argument
   518      * is a negative finite odd integer, or
   519      * <li>the first argument is negative infinity and the second
   520      * argument is a positive finite odd integer,
   521      * </ul>
   522      * then the result is negative infinity.
   523      *
   524      * <li>If the first argument is finite and less than zero
   525      * <ul>
   526      * <li> if the second argument is a finite even integer, the
   527      * result is equal to the result of raising the absolute value of
   528      * the first argument to the power of the second argument
   529      *
   530      * <li>if the second argument is a finite odd integer, the result
   531      * is equal to the negative of the result of raising the absolute
   532      * value of the first argument to the power of the second
   533      * argument
   534      *
   535      * <li>if the second argument is finite and not an integer, then
   536      * the result is NaN.
   537      * </ul>
   538      *
   539      * <li>If both arguments are integers, then the result is exactly equal
   540      * to the mathematical result of raising the first argument to the power
   541      * of the second argument if that result can in fact be represented
   542      * exactly as a {@code double} value.</ul>
   543      *
   544      * <p>(In the foregoing descriptions, a floating-point value is
   545      * considered to be an integer if and only if it is finite and a
   546      * fixed point of the method {@link #ceil ceil} or,
   547      * equivalently, a fixed point of the method {@link #floor
   548      * floor}. A value is a fixed point of a one-argument
   549      * method if and only if the result of applying the method to the
   550      * value is equal to the value.)
   551      *
   552      * <p>The computed result must be within 1 ulp of the exact result.
   553      * Results must be semi-monotonic.
   554      *
   555      * @param   a   the base.
   556      * @param   b   the exponent.
   557      * @return  the value {@code a}<sup>{@code b}</sup>.
   558      */
   559     @JavaScriptBody(args={"a", "b"}, body="return Math.pow(a, b);")
   560     public static double pow(double a, double b) {
   561         throw new UnsupportedOperationException();
   562     }
   563 
   564     /**
   565      * Returns the closest {@code int} to the argument, with ties
   566      * rounding up.
   567      *
   568      * <p>
   569      * Special cases:
   570      * <ul><li>If the argument is NaN, the result is 0.
   571      * <li>If the argument is negative infinity or any value less than or
   572      * equal to the value of {@code Integer.MIN_VALUE}, the result is
   573      * equal to the value of {@code Integer.MIN_VALUE}.
   574      * <li>If the argument is positive infinity or any value greater than or
   575      * equal to the value of {@code Integer.MAX_VALUE}, the result is
   576      * equal to the value of {@code Integer.MAX_VALUE}.</ul>
   577      *
   578      * @param   a   a floating-point value to be rounded to an integer.
   579      * @return  the value of the argument rounded to the nearest
   580      *          {@code int} value.
   581      * @see     java.lang.Integer#MAX_VALUE
   582      * @see     java.lang.Integer#MIN_VALUE
   583      */
   584     @JavaScriptBody(args="a", body="return Math.round(a);")
   585     public static int round(float a) {
   586         throw new UnsupportedOperationException();
   587     }
   588 
   589     /**
   590      * Returns the closest {@code long} to the argument, with ties
   591      * rounding up.
   592      *
   593      * <p>Special cases:
   594      * <ul><li>If the argument is NaN, the result is 0.
   595      * <li>If the argument is negative infinity or any value less than or
   596      * equal to the value of {@code Long.MIN_VALUE}, the result is
   597      * equal to the value of {@code Long.MIN_VALUE}.
   598      * <li>If the argument is positive infinity or any value greater than or
   599      * equal to the value of {@code Long.MAX_VALUE}, the result is
   600      * equal to the value of {@code Long.MAX_VALUE}.</ul>
   601      *
   602      * @param   a   a floating-point value to be rounded to a
   603      *          {@code long}.
   604      * @return  the value of the argument rounded to the nearest
   605      *          {@code long} value.
   606      * @see     java.lang.Long#MAX_VALUE
   607      * @see     java.lang.Long#MIN_VALUE
   608      */
   609     @JavaScriptBody(args="a", body="return Math.round(a);")
   610     public static long round(double a) {
   611         throw new UnsupportedOperationException();
   612     }
   613 
   614 //    private static Random randomNumberGenerator;
   615 //
   616 //    private static synchronized Random initRNG() {
   617 //        Random rnd = randomNumberGenerator;
   618 //        return (rnd == null) ? (randomNumberGenerator = new Random()) : rnd;
   619 //    }
   620 
   621     /**
   622      * Returns a {@code double} value with a positive sign, greater
   623      * than or equal to {@code 0.0} and less than {@code 1.0}.
   624      * Returned values are chosen pseudorandomly with (approximately)
   625      * uniform distribution from that range.
   626      *
   627      * <p>When this method is first called, it creates a single new
   628      * pseudorandom-number generator, exactly as if by the expression
   629      *
   630      * <blockquote>{@code new java.util.Random()}</blockquote>
   631      *
   632      * This new pseudorandom-number generator is used thereafter for
   633      * all calls to this method and is used nowhere else.
   634      *
   635      * <p>This method is properly synchronized to allow correct use by
   636      * more than one thread. However, if many threads need to generate
   637      * pseudorandom numbers at a great rate, it may reduce contention
   638      * for each thread to have its own pseudorandom-number generator.
   639      *
   640      * @return  a pseudorandom {@code double} greater than or equal
   641      * to {@code 0.0} and less than {@code 1.0}.
   642      * @see Random#nextDouble()
   643      */
   644     public static double random() {
   645         throw new UnsupportedOperationException();
   646     }
   647 
   648     /**
   649      * Returns the absolute value of an {@code int} value.
   650      * If the argument is not negative, the argument is returned.
   651      * If the argument is negative, the negation of the argument is returned.
   652      *
   653      * <p>Note that if the argument is equal to the value of
   654      * {@link Integer#MIN_VALUE}, the most negative representable
   655      * {@code int} value, the result is that same value, which is
   656      * negative.
   657      *
   658      * @param   a   the argument whose absolute value is to be determined
   659      * @return  the absolute value of the argument.
   660      */
   661     public static int abs(int a) {
   662         return (a < 0) ? -a : a;
   663     }
   664 
   665     /**
   666      * Returns the absolute value of a {@code long} value.
   667      * If the argument is not negative, the argument is returned.
   668      * If the argument is negative, the negation of the argument is returned.
   669      *
   670      * <p>Note that if the argument is equal to the value of
   671      * {@link Long#MIN_VALUE}, the most negative representable
   672      * {@code long} value, the result is that same value, which
   673      * is negative.
   674      *
   675      * @param   a   the argument whose absolute value is to be determined
   676      * @return  the absolute value of the argument.
   677      */
   678     public static long abs(long a) {
   679         return (a < 0) ? -a : a;
   680     }
   681 
   682     /**
   683      * Returns the absolute value of a {@code float} value.
   684      * If the argument is not negative, the argument is returned.
   685      * If the argument is negative, the negation of the argument is returned.
   686      * Special cases:
   687      * <ul><li>If the argument is positive zero or negative zero, the
   688      * result is positive zero.
   689      * <li>If the argument is infinite, the result is positive infinity.
   690      * <li>If the argument is NaN, the result is NaN.</ul>
   691      * In other words, the result is the same as the value of the expression:
   692      * <p>{@code Float.intBitsToFloat(0x7fffffff & Float.floatToIntBits(a))}
   693      *
   694      * @param   a   the argument whose absolute value is to be determined
   695      * @return  the absolute value of the argument.
   696      */
   697     public static float abs(float a) {
   698         return (a <= 0.0F) ? 0.0F - a : a;
   699     }
   700 
   701     /**
   702      * Returns the absolute value of a {@code double} value.
   703      * If the argument is not negative, the argument is returned.
   704      * If the argument is negative, the negation of the argument is returned.
   705      * Special cases:
   706      * <ul><li>If the argument is positive zero or negative zero, the result
   707      * is positive zero.
   708      * <li>If the argument is infinite, the result is positive infinity.
   709      * <li>If the argument is NaN, the result is NaN.</ul>
   710      * In other words, the result is the same as the value of the expression:
   711      * <p>{@code Double.longBitsToDouble((Double.doubleToLongBits(a)<<1)>>>1)}
   712      *
   713      * @param   a   the argument whose absolute value is to be determined
   714      * @return  the absolute value of the argument.
   715      */
   716     public static double abs(double a) {
   717         return (a <= 0.0D) ? 0.0D - a : a;
   718     }
   719 
   720     /**
   721      * Returns the greater of two {@code int} values. That is, the
   722      * result is the argument closer to the value of
   723      * {@link Integer#MAX_VALUE}. If the arguments have the same value,
   724      * the result is that same value.
   725      *
   726      * @param   a   an argument.
   727      * @param   b   another argument.
   728      * @return  the larger of {@code a} and {@code b}.
   729      */
   730     public static int max(int a, int b) {
   731         return (a >= b) ? a : b;
   732     }
   733 
   734     /**
   735      * Returns the greater of two {@code long} values. That is, the
   736      * result is the argument closer to the value of
   737      * {@link Long#MAX_VALUE}. If the arguments have the same value,
   738      * the result is that same value.
   739      *
   740      * @param   a   an argument.
   741      * @param   b   another argument.
   742      * @return  the larger of {@code a} and {@code b}.
   743      */
   744     public static long max(long a, long b) {
   745         return (a >= b) ? a : b;
   746     }
   747 
   748     /**
   749      * Returns the greater of two {@code float} values.  That is,
   750      * the result is the argument closer to positive infinity. If the
   751      * arguments have the same value, the result is that same
   752      * value. If either value is NaN, then the result is NaN.  Unlike
   753      * the numerical comparison operators, this method considers
   754      * negative zero to be strictly smaller than positive zero. If one
   755      * argument is positive zero and the other negative zero, the
   756      * result is positive zero.
   757      *
   758      * @param   a   an argument.
   759      * @param   b   another argument.
   760      * @return  the larger of {@code a} and {@code b}.
   761      */
   762     @JavaScriptBody(args={"a", "b"},
   763         body="return Math.max(a,b);"
   764     )
   765     public static float max(float a, float b) {
   766         throw new UnsupportedOperationException();
   767     }
   768 
   769     /**
   770      * Returns the greater of two {@code double} values.  That
   771      * is, the result is the argument closer to positive infinity. If
   772      * the arguments have the same value, the result is that same
   773      * value. If either value is NaN, then the result is NaN.  Unlike
   774      * the numerical comparison operators, this method considers
   775      * negative zero to be strictly smaller than positive zero. If one
   776      * argument is positive zero and the other negative zero, the
   777      * result is positive zero.
   778      *
   779      * @param   a   an argument.
   780      * @param   b   another argument.
   781      * @return  the larger of {@code a} and {@code b}.
   782      */
   783     @JavaScriptBody(args={"a", "b"},
   784         body="return Math.max(a,b);"
   785     )
   786     public static double max(double a, double b) {
   787         throw new UnsupportedOperationException();
   788     }
   789 
   790     /**
   791      * Returns the smaller of two {@code int} values. That is,
   792      * the result the argument closer to the value of
   793      * {@link Integer#MIN_VALUE}.  If the arguments have the same
   794      * value, the result is that same value.
   795      *
   796      * @param   a   an argument.
   797      * @param   b   another argument.
   798      * @return  the smaller of {@code a} and {@code b}.
   799      */
   800     public static int min(int a, int b) {
   801         return (a <= b) ? a : b;
   802     }
   803 
   804     /**
   805      * Returns the smaller of two {@code long} values. That is,
   806      * the result is the argument closer to the value of
   807      * {@link Long#MIN_VALUE}. If the arguments have the same
   808      * value, the result is that same value.
   809      *
   810      * @param   a   an argument.
   811      * @param   b   another argument.
   812      * @return  the smaller of {@code a} and {@code b}.
   813      */
   814     public static long min(long a, long b) {
   815         return (a <= b) ? a : b;
   816     }
   817 
   818     /**
   819      * Returns the smaller of two {@code float} values.  That is,
   820      * the result is the value closer to negative infinity. If the
   821      * arguments have the same value, the result is that same
   822      * value. If either value is NaN, then the result is NaN.  Unlike
   823      * the numerical comparison operators, this method considers
   824      * negative zero to be strictly smaller than positive zero.  If
   825      * one argument is positive zero and the other is negative zero,
   826      * the result is negative zero.
   827      *
   828      * @param   a   an argument.
   829      * @param   b   another argument.
   830      * @return  the smaller of {@code a} and {@code b}.
   831      */
   832     @JavaScriptBody(args={"a", "b"},
   833         body="return Math.min(a,b);"
   834     )
   835     public static float min(float a, float b) {
   836         throw new UnsupportedOperationException();
   837     }
   838 
   839     /**
   840      * Returns the smaller of two {@code double} values.  That
   841      * is, the result is the value closer to negative infinity. If the
   842      * arguments have the same value, the result is that same
   843      * value. If either value is NaN, then the result is NaN.  Unlike
   844      * the numerical comparison operators, this method considers
   845      * negative zero to be strictly smaller than positive zero. If one
   846      * argument is positive zero and the other is negative zero, the
   847      * result is negative zero.
   848      *
   849      * @param   a   an argument.
   850      * @param   b   another argument.
   851      * @return  the smaller of {@code a} and {@code b}.
   852      */
   853     @JavaScriptBody(args={"a", "b"},
   854         body="return Math.min(a,b);"
   855     )
   856     public static double min(double a, double b) {
   857         throw new UnsupportedOperationException();
   858     }
   859 
   860     /**
   861      * Returns the size of an ulp of the argument.  An ulp of a
   862      * {@code double} value is the positive distance between this
   863      * floating-point value and the {@code double} value next
   864      * larger in magnitude.  Note that for non-NaN <i>x</i>,
   865      * <code>ulp(-<i>x</i>) == ulp(<i>x</i>)</code>.
   866      *
   867      * <p>Special Cases:
   868      * <ul>
   869      * <li> If the argument is NaN, then the result is NaN.
   870      * <li> If the argument is positive or negative infinity, then the
   871      * result is positive infinity.
   872      * <li> If the argument is positive or negative zero, then the result is
   873      * {@code Double.MIN_VALUE}.
   874      * <li> If the argument is &plusmn;{@code Double.MAX_VALUE}, then
   875      * the result is equal to 2<sup>971</sup>.
   876      * </ul>
   877      *
   878      * @param d the floating-point value whose ulp is to be returned
   879      * @return the size of an ulp of the argument
   880      * @author Joseph D. Darcy
   881      * @since 1.5
   882      */
   883 //    public static double ulp(double d) {
   884 //        return sun.misc.FpUtils.ulp(d);
   885 //    }
   886 
   887     /**
   888      * Returns the size of an ulp of the argument.  An ulp of a
   889      * {@code float} value is the positive distance between this
   890      * floating-point value and the {@code float} value next
   891      * larger in magnitude.  Note that for non-NaN <i>x</i>,
   892      * <code>ulp(-<i>x</i>) == ulp(<i>x</i>)</code>.
   893      *
   894      * <p>Special Cases:
   895      * <ul>
   896      * <li> If the argument is NaN, then the result is NaN.
   897      * <li> If the argument is positive or negative infinity, then the
   898      * result is positive infinity.
   899      * <li> If the argument is positive or negative zero, then the result is
   900      * {@code Float.MIN_VALUE}.
   901      * <li> If the argument is &plusmn;{@code Float.MAX_VALUE}, then
   902      * the result is equal to 2<sup>104</sup>.
   903      * </ul>
   904      *
   905      * @param f the floating-point value whose ulp is to be returned
   906      * @return the size of an ulp of the argument
   907      * @author Joseph D. Darcy
   908      * @since 1.5
   909      */
   910 //    public static float ulp(float f) {
   911 //        return sun.misc.FpUtils.ulp(f);
   912 //    }
   913 
   914     /**
   915      * Returns the signum function of the argument; zero if the argument
   916      * is zero, 1.0 if the argument is greater than zero, -1.0 if the
   917      * argument is less than zero.
   918      *
   919      * <p>Special Cases:
   920      * <ul>
   921      * <li> If the argument is NaN, then the result is NaN.
   922      * <li> If the argument is positive zero or negative zero, then the
   923      *      result is the same as the argument.
   924      * </ul>
   925      *
   926      * @param d the floating-point value whose signum is to be returned
   927      * @return the signum function of the argument
   928      * @author Joseph D. Darcy
   929      * @since 1.5
   930      */
   931 //    public static double signum(double d) {
   932 //        return sun.misc.FpUtils.signum(d);
   933 //    }
   934 
   935     /**
   936      * Returns the signum function of the argument; zero if the argument
   937      * is zero, 1.0f if the argument is greater than zero, -1.0f if the
   938      * argument is less than zero.
   939      *
   940      * <p>Special Cases:
   941      * <ul>
   942      * <li> If the argument is NaN, then the result is NaN.
   943      * <li> If the argument is positive zero or negative zero, then the
   944      *      result is the same as the argument.
   945      * </ul>
   946      *
   947      * @param f the floating-point value whose signum is to be returned
   948      * @return the signum function of the argument
   949      * @author Joseph D. Darcy
   950      * @since 1.5
   951      */
   952 //    public static float signum(float f) {
   953 //        return sun.misc.FpUtils.signum(f);
   954 //    }
   955 
   956     /**
   957      * Returns the first floating-point argument with the sign of the
   958      * second floating-point argument.  Note that unlike the {@link
   959      * StrictMath#copySign(double, double) StrictMath.copySign}
   960      * method, this method does not require NaN {@code sign}
   961      * arguments to be treated as positive values; implementations are
   962      * permitted to treat some NaN arguments as positive and other NaN
   963      * arguments as negative to allow greater performance.
   964      *
   965      * @param magnitude  the parameter providing the magnitude of the result
   966      * @param sign   the parameter providing the sign of the result
   967      * @return a value with the magnitude of {@code magnitude}
   968      * and the sign of {@code sign}.
   969      * @since 1.6
   970      */
   971 //    public static double copySign(double magnitude, double sign) {
   972 //        return sun.misc.FpUtils.rawCopySign(magnitude, sign);
   973 //    }
   974 
   975     /**
   976      * Returns the first floating-point argument with the sign of the
   977      * second floating-point argument.  Note that unlike the {@link
   978      * StrictMath#copySign(float, float) StrictMath.copySign}
   979      * method, this method does not require NaN {@code sign}
   980      * arguments to be treated as positive values; implementations are
   981      * permitted to treat some NaN arguments as positive and other NaN
   982      * arguments as negative to allow greater performance.
   983      *
   984      * @param magnitude  the parameter providing the magnitude of the result
   985      * @param sign   the parameter providing the sign of the result
   986      * @return a value with the magnitude of {@code magnitude}
   987      * and the sign of {@code sign}.
   988      * @since 1.6
   989      */
   990 //    public static float copySign(float magnitude, float sign) {
   991 //        return sun.misc.FpUtils.rawCopySign(magnitude, sign);
   992 //    }
   993 
   994     /**
   995      * Returns the unbiased exponent used in the representation of a
   996      * {@code float}.  Special cases:
   997      *
   998      * <ul>
   999      * <li>If the argument is NaN or infinite, then the result is
  1000      * {@link Float#MAX_EXPONENT} + 1.
  1001      * <li>If the argument is zero or subnormal, then the result is
  1002      * {@link Float#MIN_EXPONENT} -1.
  1003      * </ul>
  1004      * @param f a {@code float} value
  1005      * @return the unbiased exponent of the argument
  1006      * @since 1.6
  1007      */
  1008 //    public static int getExponent(float f) {
  1009 //        return sun.misc.FpUtils.getExponent(f);
  1010 //    }
  1011 
  1012     /**
  1013      * Returns the unbiased exponent used in the representation of a
  1014      * {@code double}.  Special cases:
  1015      *
  1016      * <ul>
  1017      * <li>If the argument is NaN or infinite, then the result is
  1018      * {@link Double#MAX_EXPONENT} + 1.
  1019      * <li>If the argument is zero or subnormal, then the result is
  1020      * {@link Double#MIN_EXPONENT} -1.
  1021      * </ul>
  1022      * @param d a {@code double} value
  1023      * @return the unbiased exponent of the argument
  1024      * @since 1.6
  1025      */
  1026 //    public static int getExponent(double d) {
  1027 //        return sun.misc.FpUtils.getExponent(d);
  1028 //    }
  1029 
  1030     /**
  1031      * Returns the floating-point number adjacent to the first
  1032      * argument in the direction of the second argument.  If both
  1033      * arguments compare as equal the second argument is returned.
  1034      *
  1035      * <p>
  1036      * Special cases:
  1037      * <ul>
  1038      * <li> If either argument is a NaN, then NaN is returned.
  1039      *
  1040      * <li> If both arguments are signed zeros, {@code direction}
  1041      * is returned unchanged (as implied by the requirement of
  1042      * returning the second argument if the arguments compare as
  1043      * equal).
  1044      *
  1045      * <li> If {@code start} is
  1046      * &plusmn;{@link Double#MIN_VALUE} and {@code direction}
  1047      * has a value such that the result should have a smaller
  1048      * magnitude, then a zero with the same sign as {@code start}
  1049      * is returned.
  1050      *
  1051      * <li> If {@code start} is infinite and
  1052      * {@code direction} has a value such that the result should
  1053      * have a smaller magnitude, {@link Double#MAX_VALUE} with the
  1054      * same sign as {@code start} is returned.
  1055      *
  1056      * <li> If {@code start} is equal to &plusmn;
  1057      * {@link Double#MAX_VALUE} and {@code direction} has a
  1058      * value such that the result should have a larger magnitude, an
  1059      * infinity with same sign as {@code start} is returned.
  1060      * </ul>
  1061      *
  1062      * @param start  starting floating-point value
  1063      * @param direction value indicating which of
  1064      * {@code start}'s neighbors or {@code start} should
  1065      * be returned
  1066      * @return The floating-point number adjacent to {@code start} in the
  1067      * direction of {@code direction}.
  1068      * @since 1.6
  1069      */
  1070 //    public static double nextAfter(double start, double direction) {
  1071 //        return sun.misc.FpUtils.nextAfter(start, direction);
  1072 //    }
  1073 
  1074     /**
  1075      * Returns the floating-point number adjacent to the first
  1076      * argument in the direction of the second argument.  If both
  1077      * arguments compare as equal a value equivalent to the second argument
  1078      * is returned.
  1079      *
  1080      * <p>
  1081      * Special cases:
  1082      * <ul>
  1083      * <li> If either argument is a NaN, then NaN is returned.
  1084      *
  1085      * <li> If both arguments are signed zeros, a value equivalent
  1086      * to {@code direction} is returned.
  1087      *
  1088      * <li> If {@code start} is
  1089      * &plusmn;{@link Float#MIN_VALUE} and {@code direction}
  1090      * has a value such that the result should have a smaller
  1091      * magnitude, then a zero with the same sign as {@code start}
  1092      * is returned.
  1093      *
  1094      * <li> If {@code start} is infinite and
  1095      * {@code direction} has a value such that the result should
  1096      * have a smaller magnitude, {@link Float#MAX_VALUE} with the
  1097      * same sign as {@code start} is returned.
  1098      *
  1099      * <li> If {@code start} is equal to &plusmn;
  1100      * {@link Float#MAX_VALUE} and {@code direction} has a
  1101      * value such that the result should have a larger magnitude, an
  1102      * infinity with same sign as {@code start} is returned.
  1103      * </ul>
  1104      *
  1105      * @param start  starting floating-point value
  1106      * @param direction value indicating which of
  1107      * {@code start}'s neighbors or {@code start} should
  1108      * be returned
  1109      * @return The floating-point number adjacent to {@code start} in the
  1110      * direction of {@code direction}.
  1111      * @since 1.6
  1112      */
  1113 //    public static float nextAfter(float start, double direction) {
  1114 //        return sun.misc.FpUtils.nextAfter(start, direction);
  1115 //    }
  1116 
  1117     /**
  1118      * Returns the floating-point value adjacent to {@code d} in
  1119      * the direction of positive infinity.  This method is
  1120      * semantically equivalent to {@code nextAfter(d,
  1121      * Double.POSITIVE_INFINITY)}; however, a {@code nextUp}
  1122      * implementation may run faster than its equivalent
  1123      * {@code nextAfter} call.
  1124      *
  1125      * <p>Special Cases:
  1126      * <ul>
  1127      * <li> If the argument is NaN, the result is NaN.
  1128      *
  1129      * <li> If the argument is positive infinity, the result is
  1130      * positive infinity.
  1131      *
  1132      * <li> If the argument is zero, the result is
  1133      * {@link Double#MIN_VALUE}
  1134      *
  1135      * </ul>
  1136      *
  1137      * @param d starting floating-point value
  1138      * @return The adjacent floating-point value closer to positive
  1139      * infinity.
  1140      * @since 1.6
  1141      */
  1142 //    public static double nextUp(double d) {
  1143 //        return sun.misc.FpUtils.nextUp(d);
  1144 //    }
  1145 
  1146     /**
  1147      * Returns the floating-point value adjacent to {@code f} in
  1148      * the direction of positive infinity.  This method is
  1149      * semantically equivalent to {@code nextAfter(f,
  1150      * Float.POSITIVE_INFINITY)}; however, a {@code nextUp}
  1151      * implementation may run faster than its equivalent
  1152      * {@code nextAfter} call.
  1153      *
  1154      * <p>Special Cases:
  1155      * <ul>
  1156      * <li> If the argument is NaN, the result is NaN.
  1157      *
  1158      * <li> If the argument is positive infinity, the result is
  1159      * positive infinity.
  1160      *
  1161      * <li> If the argument is zero, the result is
  1162      * {@link Float#MIN_VALUE}
  1163      *
  1164      * </ul>
  1165      *
  1166      * @param f starting floating-point value
  1167      * @return The adjacent floating-point value closer to positive
  1168      * infinity.
  1169      * @since 1.6
  1170      */
  1171 //    public static float nextUp(float f) {
  1172 //        return sun.misc.FpUtils.nextUp(f);
  1173 //    }
  1174 
  1175 
  1176     /**
  1177      * Return {@code d} &times;
  1178      * 2<sup>{@code scaleFactor}</sup> rounded as if performed
  1179      * by a single correctly rounded floating-point multiply to a
  1180      * member of the double value set.  See the Java
  1181      * Language Specification for a discussion of floating-point
  1182      * value sets.  If the exponent of the result is between {@link
  1183      * Double#MIN_EXPONENT} and {@link Double#MAX_EXPONENT}, the
  1184      * answer is calculated exactly.  If the exponent of the result
  1185      * would be larger than {@code Double.MAX_EXPONENT}, an
  1186      * infinity is returned.  Note that if the result is subnormal,
  1187      * precision may be lost; that is, when {@code scalb(x, n)}
  1188      * is subnormal, {@code scalb(scalb(x, n), -n)} may not equal
  1189      * <i>x</i>.  When the result is non-NaN, the result has the same
  1190      * sign as {@code d}.
  1191      *
  1192      * <p>Special cases:
  1193      * <ul>
  1194      * <li> If the first argument is NaN, NaN is returned.
  1195      * <li> If the first argument is infinite, then an infinity of the
  1196      * same sign is returned.
  1197      * <li> If the first argument is zero, then a zero of the same
  1198      * sign is returned.
  1199      * </ul>
  1200      *
  1201      * @param d number to be scaled by a power of two.
  1202      * @param scaleFactor power of 2 used to scale {@code d}
  1203      * @return {@code d} &times; 2<sup>{@code scaleFactor}</sup>
  1204      * @since 1.6
  1205      */
  1206 //    public static double scalb(double d, int scaleFactor) {
  1207 //        return sun.misc.FpUtils.scalb(d, scaleFactor);
  1208 //    }
  1209 
  1210     /**
  1211      * Return {@code f} &times;
  1212      * 2<sup>{@code scaleFactor}</sup> rounded as if performed
  1213      * by a single correctly rounded floating-point multiply to a
  1214      * member of the float value set.  See the Java
  1215      * Language Specification for a discussion of floating-point
  1216      * value sets.  If the exponent of the result is between {@link
  1217      * Float#MIN_EXPONENT} and {@link Float#MAX_EXPONENT}, the
  1218      * answer is calculated exactly.  If the exponent of the result
  1219      * would be larger than {@code Float.MAX_EXPONENT}, an
  1220      * infinity is returned.  Note that if the result is subnormal,
  1221      * precision may be lost; that is, when {@code scalb(x, n)}
  1222      * is subnormal, {@code scalb(scalb(x, n), -n)} may not equal
  1223      * <i>x</i>.  When the result is non-NaN, the result has the same
  1224      * sign as {@code f}.
  1225      *
  1226      * <p>Special cases:
  1227      * <ul>
  1228      * <li> If the first argument is NaN, NaN is returned.
  1229      * <li> If the first argument is infinite, then an infinity of the
  1230      * same sign is returned.
  1231      * <li> If the first argument is zero, then a zero of the same
  1232      * sign is returned.
  1233      * </ul>
  1234      *
  1235      * @param f number to be scaled by a power of two.
  1236      * @param scaleFactor power of 2 used to scale {@code f}
  1237      * @return {@code f} &times; 2<sup>{@code scaleFactor}</sup>
  1238      * @since 1.6
  1239      */
  1240 //    public static float scalb(float f, int scaleFactor) {
  1241 //        return sun.misc.FpUtils.scalb(f, scaleFactor);
  1242 //    }
  1243 }