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1 /*
2  * Copyright (c) 1999, 2023, 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 dalvik.annotation.optimization.CriticalNative;
29 
30 import java.util.Random;
31 import jdk.internal.math.DoubleConsts;
32 import jdk.internal.vm.annotation.IntrinsicCandidate;
33 
34 /**
35  * The class {@code StrictMath} contains methods for performing basic
36  * numeric operations such as the elementary exponential, logarithm,
37  * square root, and trigonometric functions.
38  *
39  * <p>To help ensure portability of Java programs, the definitions of
40  * some of the numeric functions in this package require that they
41  * produce the same results as certain published algorithms. These
42  * algorithms are available from the well-known network library
43  * {@code netlib} as the package "Freely Distributable Math
44  * Library," <a
45  * href="https://www.netlib.org/fdlibm/">{@code fdlibm}</a>. These
46  * algorithms, which are written in the C programming language, are
47  * then to be understood to be transliterated into Java and executed
48  * with all floating-point and integer operations following the rules
49  * of Java arithmetic. The following transformations are used in the
50  * transliteration:
51  *
52  * <ul>
53  * <li>Extraction and setting of the high and low halves of a 64-bit
54  * {@code double} in C is expressed using Java platform methods that
55  * perform bit-wise conversions {@linkplain
56  * Double#doubleToRawLongBits(double) from {@code double} to {@code
57  * long}} and {@linkplain Double#longBitsToDouble(long) {@code long}
58  * to {@code double}}.
59  *
60  * <li>Unsigned {@code int} values in C are mapped to signed {@code
61  * int} values in Java with updates to operations to replicate
62  * unsigned semantics where the results on the same textual operation
63  * would differ. For example, {@code >>} shifts on unsigned C values
64  * are replaced with {@code >>>} shifts on signed Java values. Sized
65  * comparisons on unsigned C values ({@code <}, {@code <=}, {@code >},
66  * {@code >=}) are replaced with semantically equivalent calls to
67  * {@link Integer#compareUnsigned(int, int) compareUnsigned}.
68  * </ul>
69  *
70  * <p>The Java math library is defined with respect to
71  * {@code fdlibm} version 5.3. Where {@code fdlibm} provides
72  * more than one definition for a function (such as
73  * {@code acos}), use the "IEEE 754 core function" version
74  * (residing in a file whose name begins with the letter
75  * {@code e}).  The methods which require {@code fdlibm}
76  * semantics are {@code sin}, {@code cos}, {@code tan},
77  * {@code asin}, {@code acos}, {@code atan},
78  * {@code exp}, {@code log}, {@code log10},
79  * {@code cbrt}, {@code atan2}, {@code pow},
80  * {@code sinh}, {@code cosh}, {@code tanh},
81  * {@code hypot}, {@code expm1}, and {@code log1p}.
82  *
83  * <p>
84  * The platform uses signed two's complement integer arithmetic with
85  * int and long primitive types.  The developer should choose
86  * the primitive type to ensure that arithmetic operations consistently
87  * produce correct results, which in some cases means the operations
88  * will not overflow the range of values of the computation.
89  * The best practice is to choose the primitive type and algorithm to avoid
90  * overflow. In cases where the size is {@code int} or {@code long} and
91  * overflow errors need to be detected, the methods whose names end with
92  * {@code Exact} throw an {@code ArithmeticException} when the results overflow.
93  *
94  * <h2><a id=Ieee754RecommendedOps>IEEE 754 Recommended
95  * Operations</a></h2>
96  *
97  * The {@link java.lang.Math Math} class discusses how the shared
98  * quality of implementation criteria for selected {@code Math} and
99  * {@code StrictMath} methods <a
100  * href="Math.html#Ieee754RecommendedOps">relate to the IEEE 754
101  * recommended operations</a>.
102  *
103  * @see <a href="https://standards.ieee.org/ieee/754/6210/">
104  *      <cite>IEEE Standard for Floating-Point Arithmetic</cite></a>
105  *
106  * @author  Joseph D. Darcy
107  * @since   1.3
108  */
109 public final class StrictMath {
110 
111     /**
112      * Don't let anyone instantiate this class.
113      */
StrictMath()114     private StrictMath() {}
115 
116     /**
117      * The {@code double} value that is closer than any other to
118      * <i>e</i>, the base of the natural logarithms.
119      */
120     public static final double E = 2.718281828459045;
121 
122     /**
123      * The {@code double} value that is closer than any other to
124      * <i>pi</i> (&pi;), the ratio of the circumference of a circle to its
125      * diameter.
126      */
127     public static final double PI = 3.141592653589793;
128 
129     /**
130      * The {@code double} value that is closer than any other to
131      * <i>tau</i> (&tau;), the ratio of the circumference of a circle
132      * to its radius.
133      *
134      * @apiNote
135      * The value of <i>pi</i> is one half that of <i>tau</i>; in other
136      * words, <i>tau</i> is double <i>pi</i> .
137      *
138      * @since 19
139      */
140     public static final double TAU = 2.0 * PI;
141 
142     /**
143      * Constant by which to multiply an angular value in degrees to obtain an
144      * angular value in radians.
145      */
146     private static final double DEGREES_TO_RADIANS = 0.017453292519943295;
147 
148     /**
149      * Constant by which to multiply an angular value in radians to obtain an
150      * angular value in degrees.
151      */
152 
153     private static final double RADIANS_TO_DEGREES = 57.29577951308232;
154 
155     /**
156      * Returns the trigonometric sine of an angle. Special cases:
157      * <ul><li>If the argument is NaN or an infinity, then the
158      * result is NaN.
159      * <li>If the argument is zero, then the result is a zero with the
160      * same sign as the argument.</ul>
161      *
162      * @param   a   an angle, in radians.
163      * @return  the sine of the argument.
164      */
165     // Android-changed: Reimplement in native
166     // public static double sin(double a) {
167     //     return FdLibm.Sin.compute(a);
168     // }
169     @CriticalNative
sin(double a)170     public static native double sin(double a);
171 
172     /**
173      * Returns the trigonometric cosine of an angle. Special cases:
174      * <ul><li>If the argument is NaN or an infinity, then the
175      * result is NaN.
176      * <li>If the argument is zero, then the result is {@code 1.0}.
177      * </ul>
178      *
179      * @param   a   an angle, in radians.
180      * @return  the cosine of the argument.
181      */
182     // Android-changed: Reimplement in native
183     // public static double cos(double a) {
184     //     return FdLibm.Cos.compute(a);
185     // }
186     @CriticalNative
cos(double a)187     public static native double cos(double a);
188 
189     /**
190      * Returns the trigonometric tangent of an angle. Special cases:
191      * <ul><li>If the argument is NaN or an infinity, then the result
192      * is NaN.
193      * <li>If the argument is zero, then the result is a zero with the
194      * same sign as the argument.</ul>
195      *
196      * @param   a   an angle, in radians.
197      * @return  the tangent of the argument.
198      */
199     // Android-changed: Reimplement in native
200     // public static double tan(double a) {
201     //     return FdLibm.Tan.compute(a);
202     // }
203     @CriticalNative
tan(double a)204     public static native double tan(double a);
205 
206     /**
207      * Returns the arc sine of a value; the returned angle is in the
208      * range -<i>pi</i>/2 through <i>pi</i>/2.  Special cases:
209      * <ul><li>If the argument is NaN or its absolute value is greater
210      * than 1, then the result is NaN.
211      * <li>If the argument is zero, then the result is a zero with the
212      * same sign as the argument.</ul>
213      *
214      * @param   a   the value whose arc sine is to be returned.
215      * @return  the arc sine of the argument.
216      */
217     // Android-changed: Reimplement in native
218     // public static double asin(double a) {
219     //     return FdLibm.Asin.compute(a);
220     // }
221     @CriticalNative
asin(double a)222     public static native double asin(double a);
223 
224     /**
225      * Returns the arc cosine of a value; the returned angle is in the
226      * range 0.0 through <i>pi</i>.  Special case:
227      * <ul><li>If the argument is NaN or its absolute value is greater
228      * than 1, then the result is NaN.
229      * <li>If the argument is {@code 1.0}, the result is positive zero.
230      * </ul>
231      *
232      * @param   a   the value whose arc cosine is to be returned.
233      * @return  the arc cosine of the argument.
234      */
235     // Android-changed: Reimplement in native
236     // public static double acos(double a) {
237     //     return FdLibm.Acos.compute(a);
238     // }
239     @CriticalNative
acos(double a)240     public static native double acos(double a);
241 
242     /**
243      * Returns the arc tangent of a value; the returned angle is in the
244      * range -<i>pi</i>/2 through <i>pi</i>/2.  Special cases:
245      * <ul><li>If the argument is NaN, then the result is NaN.
246      * <li>If the argument is zero, then the result is a zero with the
247      * same sign as the argument.
248      * <li>If the argument is {@linkplain Double#isInfinite infinite},
249      * then the result is the closest value to <i>pi</i>/2 with the
250      * same sign as the input.
251      * </ul>
252      *
253      * @param   a   the value whose arc tangent is to be returned.
254      * @return  the arc tangent of the argument.
255      */
256     // Android-changed: Reimplement in native
257     // public static double atan(double a) {
258     //     return FdLibm.Atan.compute(a);
259     // }
260     @CriticalNative
atan(double a)261     public static native double atan(double a);
262 
263     /**
264      * Converts an angle measured in degrees to an approximately
265      * equivalent angle measured in radians.  The conversion from
266      * degrees to radians is generally inexact.
267      *
268      * @param   angdeg   an angle, in degrees
269      * @return  the measurement of the angle {@code angdeg}
270      *          in radians.
271      */
toRadians(double angdeg)272     public static strictfp double toRadians(double angdeg) {
273         // Do not delegate to Math.toRadians(angdeg) because
274         // this method has the strictfp modifier.
275         return angdeg * DEGREES_TO_RADIANS;
276     }
277 
278     /**
279      * Converts an angle measured in radians to an approximately
280      * equivalent angle measured in degrees.  The conversion from
281      * radians to degrees is generally inexact; users should
282      * <i>not</i> expect {@code cos(toRadians(90.0))} to exactly
283      * equal {@code 0.0}.
284      *
285      * @param   angrad   an angle, in radians
286      * @return  the measurement of the angle {@code angrad}
287      *          in degrees.
288      */
toDegrees(double angrad)289     public static strictfp double toDegrees(double angrad) {
290         // Do not delegate to Math.toDegrees(angrad) because
291         // this method has the strictfp modifier.
292         return angrad * RADIANS_TO_DEGREES;
293     }
294 
295     /**
296      * Returns Euler's number <i>e</i> raised to the power of a
297      * {@code double} value. Special cases:
298      * <ul><li>If the argument is NaN, the result is NaN.
299      * <li>If the argument is positive infinity, then the result is
300      * positive infinity.
301      * <li>If the argument is negative infinity, then the result is
302      * positive zero.
303      * <li>If the argument is zero, then the result is {@code 1.0}.
304      * </ul>
305      *
306      * @param   a   the exponent to raise <i>e</i> to.
307      * @return  the value <i>e</i><sup>{@code a}</sup>,
308      *          where <i>e</i> is the base of the natural logarithms.
309      */
310     // BEGIN Android-changed: Reimplement in native
311     /*
312     public static double exp(double a) {
313         return FdLibm.Exp.compute(a);
314     }
315     */
316     // END Android-changed: Reimplement in native
317     @CriticalNative
exp(double a)318     public static native double exp(double a);
319 
320     /**
321      * Returns the natural logarithm (base <i>e</i>) of a {@code double}
322      * value. Special cases:
323      * <ul><li>If the argument is NaN or less than zero, then the result
324      * is NaN.
325      * <li>If the argument is positive infinity, then the result is
326      * positive infinity.
327      * <li>If the argument is positive zero or negative zero, then the
328      * result is negative infinity.
329      * <li>If the argument is {@code 1.0}, then the result is positive
330      * zero.
331      * </ul>
332      *
333      * @param   a   a value
334      * @return  the value ln&nbsp;{@code a}, the natural logarithm of
335      *          {@code a}.
336      */
337     // Android-changed: Reimplement in native
338     // public static double log(double a) {
339     //     return FdLibm.Log.compute(a);
340     // }
341     @CriticalNative
log(double a)342     public static native double log(double a);
343 
344     /**
345      * Returns the base 10 logarithm of a {@code double} value.
346      * Special cases:
347      *
348      * <ul><li>If the argument is NaN or less than zero, then the result
349      * is NaN.
350      * <li>If the argument is positive infinity, then the result is
351      * positive infinity.
352      * <li>If the argument is positive zero or negative zero, then the
353      * result is negative infinity.
354      * <li>If the argument is equal to 10<sup><i>n</i></sup> for
355      * integer <i>n</i>, then the result is <i>n</i>. In particular,
356      * if the argument is {@code 1.0} (10<sup>0</sup>), then the
357      * result is positive zero.
358      * </ul>
359      *
360      * @param   a   a value
361      * @return  the base 10 logarithm of  {@code a}.
362      * @since 1.5
363      */
364     // Android-changed: Reimplement in native
365     // public static double log10(double a) {
366     //     return FdLibm.Log10.compute(a);
367     // }
368     @CriticalNative
log10(double a)369     public static native double log10(double a);
370 
371     /**
372      * Returns the correctly rounded positive square root of a
373      * {@code double} value.
374      * Special cases:
375      * <ul><li>If the argument is NaN or less than zero, then the result
376      * is NaN.
377      * <li>If the argument is positive infinity, then the result is positive
378      * infinity.
379      * <li>If the argument is positive zero or negative zero, then the
380      * result is the same as the argument.</ul>
381      * Otherwise, the result is the {@code double} value closest to
382      * the true mathematical square root of the argument value.
383      *
384      * @param   a   a value.
385      * @return  the positive square root of {@code a}.
386      */
387     @IntrinsicCandidate
388     // Android-changed: Reimplement in native
389     // public static double sqrt(double a) {
390     //     return FdLibm.Sqrt.compute(a);
391     // }
392     @CriticalNative
sqrt(double a)393     public static native double sqrt(double a);
394 
395     /**
396      * Returns the cube root of a {@code double} value.  For
397      * positive finite {@code x}, {@code cbrt(-x) ==
398      * -cbrt(x)}; that is, the cube root of a negative value is
399      * the negative of the cube root of that value's magnitude.
400      * Special cases:
401      *
402      * <ul>
403      *
404      * <li>If the argument is NaN, then the result is NaN.
405      *
406      * <li>If the argument is infinite, then the result is an infinity
407      * with the same sign as the argument.
408      *
409      * <li>If the argument is zero, then the result is a zero with the
410      * same sign as the argument.
411      *
412      * </ul>
413      *
414      * @param   a   a value.
415      * @return  the cube root of {@code a}.
416      * @since 1.5
417      */
418     // BEGIN Android-changed: Reimplement in native
419     /*
420     public static double cbrt(double a) {
421         return FdLibm.Cbrt.compute(a);
422     }
423     */
424     // END Android-changed: Reimplement in native
425     @CriticalNative
cbrt(double a)426     public static native double cbrt(double a);
427 
428     /**
429      * Computes the remainder operation on two arguments as prescribed
430      * by the IEEE 754 standard.
431      * The remainder value is mathematically equal to
432      * <code>f1&nbsp;-&nbsp;f2</code>&nbsp;&times;&nbsp;<i>n</i>,
433      * where <i>n</i> is the mathematical integer closest to the exact
434      * mathematical value of the quotient {@code f1/f2}, and if two
435      * mathematical integers are equally close to {@code f1/f2},
436      * then <i>n</i> is the integer that is even. If the remainder is
437      * zero, its sign is the same as the sign of the first argument.
438      * Special cases:
439      * <ul><li>If either argument is NaN, or the first argument is infinite,
440      * or the second argument is positive zero or negative zero, then the
441      * result is NaN.
442      * <li>If the first argument is finite and the second argument is
443      * infinite, then the result is the same as the first argument.</ul>
444      *
445      * @param   f1   the dividend.
446      * @param   f2   the divisor.
447      * @return  the remainder when {@code f1} is divided by
448      *          {@code f2}.
449      */
450     // Android-changed: Reimplement in native
451     // public static double IEEEremainder(double f1, double f2) {
452     //     return FdLibm.IEEEremainder.compute(f1, f2);
453     // }
454     @CriticalNative
IEEEremainder(double f1, double f2)455     public static native double IEEEremainder(double f1, double f2);
456 
457     /**
458      * Returns the smallest (closest to negative infinity)
459      * {@code double} value that is greater than or equal to the
460      * argument and is equal to a mathematical integer. Special cases:
461      * <ul><li>If the argument value is already equal to a
462      * mathematical integer, then the result is the same as the
463      * argument.  <li>If the argument is NaN or an infinity or
464      * positive zero or negative zero, then the result is the same as
465      * the argument.  <li>If the argument value is less than zero but
466      * greater than -1.0, then the result is negative zero.</ul> Note
467      * that the value of {@code StrictMath.ceil(x)} is exactly the
468      * value of {@code -StrictMath.floor(-x)}.
469      *
470      * @param   a   a value.
471      * @return  the smallest (closest to negative infinity)
472      *          floating-point value that is greater than or equal to
473      *          the argument and is equal to a mathematical integer.
474      */
ceil(double a)475     public static double ceil(double a) {
476         return floorOrCeil(a, -0.0, 1.0, 1.0);
477     }
478 
479     /**
480      * Returns the largest (closest to positive infinity)
481      * {@code double} value that is less than or equal to the
482      * argument and is equal to a mathematical integer. Special cases:
483      * <ul><li>If the argument value is already equal to a
484      * mathematical integer, then the result is the same as the
485      * argument.  <li>If the argument is NaN or an infinity or
486      * positive zero or negative zero, then the result is the same as
487      * the argument.</ul>
488      *
489      * @param   a   a value.
490      * @return  the largest (closest to positive infinity)
491      *          floating-point value that less than or equal to the argument
492      *          and is equal to a mathematical integer.
493      */
floor(double a)494     public static double floor(double a) {
495         return floorOrCeil(a, -1.0, 0.0, -1.0);
496     }
497 
498     /**
499      * Internal method to share logic between floor and ceil.
500      *
501      * @param a the value to be floored or ceiled
502      * @param negativeBoundary result for values in (-1, 0)
503      * @param positiveBoundary result for values in (0, 1)
504      * @param sign the sign of the result
505      */
floorOrCeil(double a, double negativeBoundary, double positiveBoundary, double sign)506     private static double floorOrCeil(double a,
507                                       double negativeBoundary,
508                                       double positiveBoundary,
509                                       double sign) {
510         int exponent = Math.getExponent(a);
511 
512         if (exponent < 0) {
513             /*
514              * Absolute value of argument is less than 1.
515              * floorOrCeil(-0.0) => -0.0
516              * floorOrCeil(+0.0) => +0.0
517              */
518             return ((a == 0.0) ? a :
519                     ( (a < 0.0) ?  negativeBoundary : positiveBoundary) );
520         } else if (exponent >= 52) {
521             /*
522              * Infinity, NaN, or a value so large it must be integral.
523              */
524             return a;
525         }
526         // Else the argument is either an integral value already XOR it
527         // has to be rounded to one.
528         assert exponent >= 0 && exponent <= 51;
529 
530         long doppel = Double.doubleToRawLongBits(a);
531         long mask   = DoubleConsts.SIGNIF_BIT_MASK >> exponent;
532 
533         if ( (mask & doppel) == 0L )
534             return a; // integral value
535         else {
536             double result = Double.longBitsToDouble(doppel & (~mask));
537             if (sign*a > 0.0)
538                 result = result + sign;
539             return result;
540         }
541     }
542 
543     /**
544      * Returns the {@code double} value that is closest in value
545      * to the argument and is equal to a mathematical integer. If two
546      * {@code double} values that are mathematical integers are
547      * equally close to the value of the argument, the result is the
548      * integer value that is even. Special cases:
549      * <ul><li>If the argument value is already equal to a mathematical
550      * integer, then the result is the same as the argument.
551      * <li>If the argument is NaN or an infinity or positive zero or negative
552      * zero, then the result is the same as the argument.</ul>
553      *
554      * @param   a   a value.
555      * @return  the closest floating-point value to {@code a} that is
556      *          equal to a mathematical integer.
557      * @author Joseph D. Darcy
558      */
rint(double a)559     public static double rint(double a) {
560         /*
561          * If the absolute value of a is not less than 2^52, it
562          * is either a finite integer (the double format does not have
563          * enough significand bits for a number that large to have any
564          * fractional portion), an infinity, or a NaN.  In any of
565          * these cases, rint of the argument is the argument.
566          *
567          * Otherwise, the sum (twoToThe52 + a ) will properly round
568          * away any fractional portion of a since ulp(twoToThe52) ==
569          * 1.0; subtracting out twoToThe52 from this sum will then be
570          * exact and leave the rounded integer portion of a.
571          */
572         double twoToThe52 = (double)(1L << 52); // 2^52
573         double sign = Math.copySign(1.0, a); // preserve sign info
574         a = Math.abs(a);
575 
576         if (a < twoToThe52) { // E_min <= ilogb(a) <= 51
577             a = ((twoToThe52 + a ) - twoToThe52);
578         }
579 
580         return sign * a; // restore original sign
581     }
582 
583     /**
584      * Returns the angle <i>theta</i> from the conversion of rectangular
585      * coordinates ({@code x},&nbsp;{@code y}) to polar
586      * coordinates (r,&nbsp;<i>theta</i>).
587      * This method computes the phase <i>theta</i> by computing an arc tangent
588      * of {@code y/x} in the range of -<i>pi</i> to <i>pi</i>. Special
589      * cases:
590      * <ul><li>If either argument is NaN, then the result is NaN.
591      * <li>If the first argument is positive zero and the second argument
592      * is positive, or the first argument is positive and finite and the
593      * second argument is positive infinity, then the result is positive
594      * zero.
595      * <li>If the first argument is negative zero and the second argument
596      * is positive, or the first argument is negative and finite and the
597      * second argument is positive infinity, then the result is negative zero.
598      * <li>If the first argument is positive zero and the second argument
599      * is negative, or the first argument is positive and finite and the
600      * second argument is negative infinity, then the result is the
601      * {@code double} value closest to <i>pi</i>.
602      * <li>If the first argument is negative zero and the second argument
603      * is negative, or the first argument is negative and finite and the
604      * second argument is negative infinity, then the result is the
605      * {@code double} value closest to -<i>pi</i>.
606      * <li>If the first argument is positive and the second argument is
607      * positive zero or negative zero, or the first argument is positive
608      * infinity and the second argument is finite, then the result is the
609      * {@code double} value closest to <i>pi</i>/2.
610      * <li>If the first argument is negative and the second argument is
611      * positive zero or negative zero, or the first argument is negative
612      * infinity and the second argument is finite, then the result is the
613      * {@code double} value closest to -<i>pi</i>/2.
614      * <li>If both arguments are positive infinity, then the result is the
615      * {@code double} value closest to <i>pi</i>/4.
616      * <li>If the first argument is positive infinity and the second argument
617      * is negative infinity, then the result is the {@code double}
618      * value closest to 3*<i>pi</i>/4.
619      * <li>If the first argument is negative infinity and the second argument
620      * is positive infinity, then the result is the {@code double} value
621      * closest to -<i>pi</i>/4.
622      * <li>If both arguments are negative infinity, then the result is the
623      * {@code double} value closest to -3*<i>pi</i>/4.</ul>
624      *
625      * @apiNote
626      * For <i>y</i> with a positive sign and finite nonzero
627      * <i>x</i>, the exact mathematical value of {@code atan2} is
628      * equal to:
629      * <ul>
630      * <li>If <i>x</i> {@literal >} 0, atan(abs(<i>y</i>/<i>x</i>))
631      * <li>If <i>x</i> {@literal <} 0, &pi; - atan(abs(<i>y</i>/<i>x</i>))
632      * </ul>
633      *
634      * @param   y   the ordinate coordinate
635      * @param   x   the abscissa coordinate
636      * @return  the <i>theta</i> component of the point
637      *          (<i>r</i>,&nbsp;<i>theta</i>)
638      *          in polar coordinates that corresponds to the point
639      *          (<i>x</i>,&nbsp;<i>y</i>) in Cartesian coordinates.
640      */
641     // Android-changed: Reimplement in native
642     // public static double atan2(double y, double x) {
643     //     return FdLibm.Atan2.compute(y, x);
644     // }
645     @CriticalNative
atan2(double y, double x)646     public static native double atan2(double y, double x);
647 
648     /**
649      * Returns the value of the first argument raised to the power of the
650      * second argument. Special cases:
651      *
652      * <ul><li>If the second argument is positive or negative zero, then the
653      * result is 1.0.
654      * <li>If the second argument is 1.0, then the result is the same as the
655      * first argument.
656      * <li>If the second argument is NaN, then the result is NaN.
657      * <li>If the first argument is NaN and the second argument is nonzero,
658      * then the result is NaN.
659      *
660      * <li>If
661      * <ul>
662      * <li>the absolute value of the first argument is greater than 1
663      * and the second argument is positive infinity, or
664      * <li>the absolute value of the first argument is less than 1 and
665      * the second argument is negative infinity,
666      * </ul>
667      * then the result is positive infinity.
668      *
669      * <li>If
670      * <ul>
671      * <li>the absolute value of the first argument is greater than 1 and
672      * the second argument is negative infinity, or
673      * <li>the absolute value of the
674      * first argument is less than 1 and the second argument is positive
675      * infinity,
676      * </ul>
677      * then the result is positive zero.
678      *
679      * <li>If the absolute value of the first argument equals 1 and the
680      * second argument is infinite, then the result is NaN.
681      *
682      * <li>If
683      * <ul>
684      * <li>the first argument is positive zero and the second argument
685      * is greater than zero, or
686      * <li>the first argument is positive infinity and the second
687      * argument is less than zero,
688      * </ul>
689      * then the result is positive zero.
690      *
691      * <li>If
692      * <ul>
693      * <li>the first argument is positive zero and the second argument
694      * is less than zero, or
695      * <li>the first argument is positive infinity and the second
696      * argument is greater than zero,
697      * </ul>
698      * then the result is positive infinity.
699      *
700      * <li>If
701      * <ul>
702      * <li>the first argument is negative zero and the second argument
703      * is greater than zero but not a finite odd integer, or
704      * <li>the first argument is negative infinity and the second
705      * argument is less than zero but not a finite odd integer,
706      * </ul>
707      * then the result is positive zero.
708      *
709      * <li>If
710      * <ul>
711      * <li>the first argument is negative zero and the second argument
712      * is a positive finite odd integer, or
713      * <li>the first argument is negative infinity and the second
714      * argument is a negative finite odd integer,
715      * </ul>
716      * then the result is negative zero.
717      *
718      * <li>If
719      * <ul>
720      * <li>the first argument is negative zero and the second argument
721      * is less than zero but not a finite odd integer, or
722      * <li>the first argument is negative infinity and the second
723      * argument is greater than zero but not a finite odd integer,
724      * </ul>
725      * then the result is positive infinity.
726      *
727      * <li>If
728      * <ul>
729      * <li>the first argument is negative zero and the second argument
730      * is a negative finite odd integer, or
731      * <li>the first argument is negative infinity and the second
732      * argument is a positive finite odd integer,
733      * </ul>
734      * then the result is negative infinity.
735      *
736      * <li>If the first argument is finite and less than zero
737      * <ul>
738      * <li> if the second argument is a finite even integer, the
739      * result is equal to the result of raising the absolute value of
740      * the first argument to the power of the second argument
741      *
742      * <li>if the second argument is a finite odd integer, the result
743      * is equal to the negative of the result of raising the absolute
744      * value of the first argument to the power of the second
745      * argument
746      *
747      * <li>if the second argument is finite and not an integer, then
748      * the result is NaN.
749      * </ul>
750      *
751      * <li>If both arguments are integers, then the result is exactly equal
752      * to the mathematical result of raising the first argument to the power
753      * of the second argument if that result can in fact be represented
754      * exactly as a {@code double} value.</ul>
755      *
756      * <p>(In the foregoing descriptions, a floating-point value is
757      * considered to be an integer if and only if it is finite and a
758      * fixed point of the method {@link #ceil ceil} or,
759      * equivalently, a fixed point of the method {@link #floor
760      * floor}. A value is a fixed point of a one-argument
761      * method if and only if the result of applying the method to the
762      * value is equal to the value.)
763      *
764      * @apiNote
765      * The special cases definitions of this method differ from the
766      * special case definitions of the IEEE 754 recommended {@code
767      * pow} operation for &plusmn;{@code 1.0} raised to an infinite
768      * power. This method treats such cases as indeterminate and
769      * specifies a NaN is returned. The IEEE 754 specification treats
770      * the infinite power as a large integer (large-magnitude
771      * floating-point numbers are numerically integers, specifically
772      * even integers) and therefore specifies {@code 1.0} be returned.
773      *
774      * @param   a   base.
775      * @param   b   the exponent.
776      * @return  the value {@code a}<sup>{@code b}</sup>.
777      */
778     // BEGIN Android-changed: Reimplement in native
779     /*
780     public static double pow(double a, double b) {
781         return FdLibm.Pow.compute(a, b);
782     }
783     */
784     // END Android-changed: Reimplement in native
785     @CriticalNative
pow(double a, double b)786     public static native double pow(double a, double b);
787 
788     /**
789      * Returns the closest {@code int} to the argument, with ties
790      * rounding to positive infinity.
791      *
792      * <p>Special cases:
793      * <ul><li>If the argument is NaN, the result is 0.
794      * <li>If the argument is negative infinity or any value less than or
795      * equal to the value of {@code Integer.MIN_VALUE}, the result is
796      * equal to the value of {@code Integer.MIN_VALUE}.
797      * <li>If the argument is positive infinity or any value greater than or
798      * equal to the value of {@code Integer.MAX_VALUE}, the result is
799      * equal to the value of {@code Integer.MAX_VALUE}.</ul>
800      *
801      * @param   a   a floating-point value to be rounded to an integer.
802      * @return  the value of the argument rounded to the nearest
803      *          {@code int} value.
804      * @see     java.lang.Integer#MAX_VALUE
805      * @see     java.lang.Integer#MIN_VALUE
806      */
round(float a)807     public static int round(float a) {
808         return Math.round(a);
809     }
810 
811     /**
812      * Returns the closest {@code long} to the argument, with ties
813      * rounding to positive infinity.
814      *
815      * <p>Special cases:
816      * <ul><li>If the argument is NaN, the result is 0.
817      * <li>If the argument is negative infinity or any value less than or
818      * equal to the value of {@code Long.MIN_VALUE}, the result is
819      * equal to the value of {@code Long.MIN_VALUE}.
820      * <li>If the argument is positive infinity or any value greater than or
821      * equal to the value of {@code Long.MAX_VALUE}, the result is
822      * equal to the value of {@code Long.MAX_VALUE}.</ul>
823      *
824      * @param   a  a floating-point value to be rounded to a
825      *          {@code long}.
826      * @return  the value of the argument rounded to the nearest
827      *          {@code long} value.
828      * @see     java.lang.Long#MAX_VALUE
829      * @see     java.lang.Long#MIN_VALUE
830      */
round(double a)831     public static long round(double a) {
832         return Math.round(a);
833     }
834 
835     private static final class RandomNumberGeneratorHolder {
836         static final Random randomNumberGenerator = new Random();
837     }
838 
839     /**
840      * Returns a {@code double} value with a positive sign, greater
841      * than or equal to {@code 0.0} and less than {@code 1.0}.
842      * Returned values are chosen pseudorandomly with (approximately)
843      * uniform distribution from that range.
844      *
845      * <p>When this method is first called, it creates a single new
846      * pseudorandom-number generator, exactly as if by the expression
847      *
848      * <blockquote>{@code new java.util.Random()}</blockquote>
849      *
850      * This new pseudorandom-number generator is used thereafter for
851      * all calls to this method and is used nowhere else.
852      *
853      * <p>This method is properly synchronized to allow correct use by
854      * more than one thread. However, if many threads need to generate
855      * pseudorandom numbers at a great rate, it may reduce contention
856      * for each thread to have its own pseudorandom-number generator.
857      *
858      * @return  a pseudorandom {@code double} greater than or equal
859      * to {@code 0.0} and less than {@code 1.0}.
860      * @see Random#nextDouble()
861      */
random()862     public static double random() {
863         return RandomNumberGeneratorHolder.randomNumberGenerator.nextDouble();
864     }
865 
866     /**
867      * Returns the sum of its arguments,
868      * throwing an exception if the result overflows an {@code int}.
869      *
870      * @param x the first value
871      * @param y the second value
872      * @return the result
873      * @throws ArithmeticException if the result overflows an int
874      * @see Math#addExact(int,int)
875      * @since 1.8
876      */
addExact(int x, int y)877     public static int addExact(int x, int y) {
878         return Math.addExact(x, y);
879     }
880 
881     /**
882      * Returns the sum of its arguments,
883      * throwing an exception if the result overflows a {@code long}.
884      *
885      * @param x the first value
886      * @param y the second value
887      * @return the result
888      * @throws ArithmeticException if the result overflows a long
889      * @see Math#addExact(long,long)
890      * @since 1.8
891      */
addExact(long x, long y)892     public static long addExact(long x, long y) {
893         return Math.addExact(x, y);
894     }
895 
896     /**
897      * Returns the difference of the arguments,
898      * throwing an exception if the result overflows an {@code int}.
899      *
900      * @param x the first value
901      * @param y the second value to subtract from the first
902      * @return the result
903      * @throws ArithmeticException if the result overflows an int
904      * @see Math#subtractExact(int,int)
905      * @since 1.8
906      */
subtractExact(int x, int y)907     public static int subtractExact(int x, int y) {
908         return Math.subtractExact(x, y);
909     }
910 
911     /**
912      * Returns the difference of the arguments,
913      * throwing an exception if the result overflows a {@code long}.
914      *
915      * @param x the first value
916      * @param y the second value to subtract from the first
917      * @return the result
918      * @throws ArithmeticException if the result overflows a long
919      * @see Math#subtractExact(long,long)
920      * @since 1.8
921      */
subtractExact(long x, long y)922     public static long subtractExact(long x, long y) {
923         return Math.subtractExact(x, y);
924     }
925 
926     /**
927      * Returns the product of the arguments,
928      * throwing an exception if the result overflows an {@code int}.
929      *
930      * @param x the first value
931      * @param y the second value
932      * @return the result
933      * @throws ArithmeticException if the result overflows an int
934      * @see Math#multiplyExact(int,int)
935      * @since 1.8
936      */
multiplyExact(int x, int y)937     public static int multiplyExact(int x, int y) {
938         return Math.multiplyExact(x, y);
939     }
940 
941     /**
942      * Returns the product of the arguments, throwing an exception if the result
943      * overflows a {@code long}.
944      *
945      * @param x the first value
946      * @param y the second value
947      * @return the result
948      * @throws ArithmeticException if the result overflows a long
949      * @see Math#multiplyExact(long,int)
950      * @since 9
951      */
multiplyExact(long x, int y)952     public static long multiplyExact(long x, int y) {
953         return Math.multiplyExact(x, y);
954     }
955 
956     /**
957      * Returns the product of the arguments,
958      * throwing an exception if the result overflows a {@code long}.
959      *
960      * @param x the first value
961      * @param y the second value
962      * @return the result
963      * @throws ArithmeticException if the result overflows a long
964      * @see Math#multiplyExact(long,long)
965      * @since 1.8
966      */
multiplyExact(long x, long y)967     public static long multiplyExact(long x, long y) {
968         return Math.multiplyExact(x, y);
969     }
970 
971     /**
972      * Returns the quotient of the arguments, throwing an exception if the
973      * result overflows an {@code int}.  Such overflow occurs in this method if
974      * {@code x} is {@link Integer#MIN_VALUE} and {@code y} is {@code -1}.
975      * In contrast, if {@code Integer.MIN_VALUE / -1} were evaluated directly,
976      * the result would be {@code Integer.MIN_VALUE} and no exception would be
977      * thrown.
978      * <p>
979      * If {@code y} is zero, an {@code ArithmeticException} is thrown
980      * (JLS {@jls 15.17.2}).
981      * <p>
982      * The built-in remainder operator "{@code %}" is a suitable counterpart
983      * both for this method and for the built-in division operator "{@code /}".
984      *
985      * @param x the dividend
986      * @param y the divisor
987      * @return the quotient {@code x / y}
988      * @throws ArithmeticException if {@code y} is zero or the quotient
989      * overflows an int
990      * @jls 15.17.2 Division Operator /
991      * @see Math#divideExact(int,int)
992      * @since 18
993      */
divideExact(int x, int y)994     public static int divideExact(int x, int y) {
995         return Math.divideExact(x, y);
996     }
997 
998     /**
999      * Returns the quotient of the arguments, throwing an exception if the
1000      * result overflows a {@code long}.  Such overflow occurs in this method if
1001      * {@code x} is {@link Long#MIN_VALUE} and {@code y} is {@code -1}.
1002      * In contrast, if {@code Long.MIN_VALUE / -1} were evaluated directly,
1003      * the result would be {@code Long.MIN_VALUE} and no exception would be
1004      * thrown.
1005      * <p>
1006      * If {@code y} is zero, an {@code ArithmeticException} is thrown
1007      * (JLS {@jls 15.17.2}).
1008      * <p>
1009      * The built-in remainder operator "{@code %}" is a suitable counterpart
1010      * both for this method and for the built-in division operator "{@code /}".
1011      *
1012      * @param x the dividend
1013      * @param y the divisor
1014      * @return the quotient {@code x / y}
1015      * @throws ArithmeticException if {@code y} is zero or the quotient
1016      * overflows a long
1017      * @jls 15.17.2 Division Operator /
1018      * @see Math#divideExact(long,long)
1019      * @since 18
1020      */
divideExact(long x, long y)1021     public static long divideExact(long x, long y) {
1022         return Math.divideExact(x, y);
1023     }
1024 
1025     /**
1026      * Returns the largest (closest to positive infinity)
1027      * {@code int} value that is less than or equal to the algebraic quotient.
1028      * This method is identical to {@link #floorDiv(int,int)} except that it
1029      * throws an {@code ArithmeticException} when the dividend is
1030      * {@linkplain Integer#MIN_VALUE Integer.MIN_VALUE} and the divisor is
1031      * {@code -1} instead of ignoring the integer overflow and returning
1032      * {@code Integer.MIN_VALUE}.
1033      * <p>
1034      * The floor modulus method {@link #floorMod(int,int)} is a suitable
1035      * counterpart both for this method and for the {@link #floorDiv(int,int)}
1036      * method.
1037      * <p>
1038      * See {@link Math#floorDiv(int, int) Math.floorDiv} for examples and
1039      * a comparison to the integer division {@code /} operator.
1040      *
1041      * @param x the dividend
1042      * @param y the divisor
1043      * @return the largest (closest to positive infinity)
1044      * {@code int} value that is less than or equal to the algebraic quotient.
1045      * @throws ArithmeticException if the divisor {@code y} is zero, or the
1046      * dividend {@code x} is {@code Integer.MIN_VALUE} and the divisor {@code y}
1047      * is {@code -1}.
1048      * @see Math#floorDiv(int, int)
1049      * @since 18
1050      */
floorDivExact(int x, int y)1051     public static int floorDivExact(int x, int y) {
1052         return Math.floorDivExact(x, y);
1053     }
1054 
1055     /**
1056      * Returns the largest (closest to positive infinity)
1057      * {@code long} value that is less than or equal to the algebraic quotient.
1058      * This method is identical to {@link #floorDiv(long,long)} except that it
1059      * throws an {@code ArithmeticException} when the dividend is
1060      * {@linkplain Long#MIN_VALUE Long.MIN_VALUE} and the divisor is
1061      * {@code -1} instead of ignoring the integer overflow and returning
1062      * {@code Long.MIN_VALUE}.
1063      * <p>
1064      * The floor modulus method {@link #floorMod(long,long)} is a suitable
1065      * counterpart both for this method and for the {@link #floorDiv(long,long)}
1066      * method.
1067      * <p>
1068      * For examples, see {@link Math#floorDiv(int, int) Math.floorDiv}.
1069      *
1070      * @param x the dividend
1071      * @param y the divisor
1072      * @return the largest (closest to positive infinity)
1073      * {@code long} value that is less than or equal to the algebraic quotient.
1074      * @throws ArithmeticException if the divisor {@code y} is zero, or the
1075      * dividend {@code x} is {@code Long.MIN_VALUE} and the divisor {@code y}
1076      * is {@code -1}.
1077      * @see Math#floorDiv(int, int)
1078      * @see Math#floorDiv(long,long)
1079      * @since 18
1080      */
floorDivExact(long x, long y)1081     public static long floorDivExact(long x, long y) {
1082         return Math.floorDivExact(x, y);
1083     }
1084 
1085     /**
1086      * Returns the smallest (closest to negative infinity)
1087      * {@code int} value that is greater than or equal to the algebraic quotient.
1088      * This method is identical to {@link #ceilDiv(int,int)} except that it
1089      * throws an {@code ArithmeticException} when the dividend is
1090      * {@linkplain Integer#MIN_VALUE Integer.MIN_VALUE} and the divisor is
1091      * {@code -1} instead of ignoring the integer overflow and returning
1092      * {@code Integer.MIN_VALUE}.
1093      * <p>
1094      * The ceil modulus method {@link #ceilMod(int,int)} is a suitable
1095      * counterpart both for this method and for the {@link #ceilDiv(int,int)}
1096      * method.
1097      * <p>
1098      * See {@link Math#ceilDiv(int, int) Math.ceilDiv} for examples and
1099      * a comparison to the integer division {@code /} operator.
1100      *
1101      * @param x the dividend
1102      * @param y the divisor
1103      * @return the smallest (closest to negative infinity)
1104      * {@code int} value that is greater than or equal to the algebraic quotient.
1105      * @throws ArithmeticException if the divisor {@code y} is zero, or the
1106      * dividend {@code x} is {@code Integer.MIN_VALUE} and the divisor {@code y}
1107      * is {@code -1}.
1108      * @see Math#ceilDiv(int, int)
1109      * @since 18
1110      */
ceilDivExact(int x, int y)1111     public static int ceilDivExact(int x, int y) {
1112         return Math.ceilDivExact(x, y);
1113     }
1114 
1115     /**
1116      * Returns the smallest (closest to negative infinity)
1117      * {@code long} value that is greater than or equal to the algebraic quotient.
1118      * This method is identical to {@link #ceilDiv(long,long)} except that it
1119      * throws an {@code ArithmeticException} when the dividend is
1120      * {@linkplain Long#MIN_VALUE Long.MIN_VALUE} and the divisor is
1121      * {@code -1} instead of ignoring the integer overflow and returning
1122      * {@code Long.MIN_VALUE}.
1123      * <p>
1124      * The ceil modulus method {@link #ceilMod(long,long)} is a suitable
1125      * counterpart both for this method and for the {@link #ceilDiv(long,long)}
1126      * method.
1127      * <p>
1128      * For examples, see {@link Math#ceilDiv(int, int) Math.ceilDiv}.
1129      *
1130      * @param x the dividend
1131      * @param y the divisor
1132      * @return the smallest (closest to negative infinity)
1133      * {@code long} value that is greater than or equal to the algebraic quotient.
1134      * @throws ArithmeticException if the divisor {@code y} is zero, or the
1135      * dividend {@code x} is {@code Long.MIN_VALUE} and the divisor {@code y}
1136      * is {@code -1}.
1137      * @see Math#ceilDiv(int, int)
1138      * @see Math#ceilDiv(long,long)
1139      * @since 18
1140      */
ceilDivExact(long x, long y)1141     public static long ceilDivExact(long x, long y) {
1142         return Math.ceilDivExact(x, y);
1143     }
1144 
1145     /**
1146      * Returns the argument incremented by one,
1147      * throwing an exception if the result overflows an {@code int}.
1148      * The overflow only occurs for {@linkplain Integer#MAX_VALUE the maximum value}.
1149      *
1150      * @param a the value to increment
1151      * @return the result
1152      * @throws ArithmeticException if the result overflows an int
1153      * @see Math#incrementExact(int)
1154      * @since 14
1155      */
incrementExact(int a)1156     public static int incrementExact(int a) {
1157         return Math.incrementExact(a);
1158     }
1159 
1160     /**
1161      * Returns the argument incremented by one,
1162      * throwing an exception if the result overflows a {@code long}.
1163      * The overflow only occurs for {@linkplain Long#MAX_VALUE the maximum value}.
1164      *
1165      * @param a the value to increment
1166      * @return the result
1167      * @throws ArithmeticException if the result overflows a long
1168      * @see Math#incrementExact(long)
1169      * @since 14
1170      */
incrementExact(long a)1171     public static long incrementExact(long a) {
1172         return Math.incrementExact(a);
1173     }
1174 
1175     /**
1176      * Returns the argument decremented by one,
1177      * throwing an exception if the result overflows an {@code int}.
1178      * The overflow only occurs for {@linkplain Integer#MIN_VALUE the minimum value}.
1179      *
1180      * @param a the value to decrement
1181      * @return the result
1182      * @throws ArithmeticException if the result overflows an int
1183      * @see Math#decrementExact(int)
1184      * @since 14
1185      */
decrementExact(int a)1186     public static int decrementExact(int a) {
1187         return Math.decrementExact(a);
1188     }
1189 
1190     /**
1191      * Returns the argument decremented by one,
1192      * throwing an exception if the result overflows a {@code long}.
1193      * The overflow only occurs for {@linkplain Long#MIN_VALUE the minimum value}.
1194      *
1195      * @param a the value to decrement
1196      * @return the result
1197      * @throws ArithmeticException if the result overflows a long
1198      * @see Math#decrementExact(long)
1199      * @since 14
1200      */
decrementExact(long a)1201     public static long decrementExact(long a) {
1202         return Math.decrementExact(a);
1203     }
1204 
1205     /**
1206      * Returns the negation of the argument,
1207      * throwing an exception if the result overflows an {@code int}.
1208      * The overflow only occurs for {@linkplain Integer#MIN_VALUE the minimum value}.
1209      *
1210      * @param a the value to negate
1211      * @return the result
1212      * @throws ArithmeticException if the result overflows an int
1213      * @see Math#negateExact(int)
1214      * @since 14
1215      */
negateExact(int a)1216     public static int negateExact(int a) {
1217         return Math.negateExact(a);
1218     }
1219 
1220     /**
1221      * Returns the negation of the argument,
1222      * throwing an exception if the result overflows a {@code long}.
1223      * The overflow only occurs for {@linkplain Long#MIN_VALUE the minimum value}.
1224      *
1225      * @param a the value to negate
1226      * @return the result
1227      * @throws ArithmeticException if the result overflows a long
1228      * @see Math#negateExact(long)
1229      * @since 14
1230      */
negateExact(long a)1231     public static long negateExact(long a) {
1232         return Math.negateExact(a);
1233     }
1234 
1235     /**
1236      * Returns the value of the {@code long} argument, throwing an exception
1237      * if the value overflows an {@code int}.
1238      *
1239      * @param value the long value
1240      * @return the argument as an int
1241      * @throws ArithmeticException if the {@code argument} overflows an int
1242      * @see Math#toIntExact(long)
1243      * @since 1.8
1244      */
toIntExact(long value)1245     public static int toIntExact(long value) {
1246         return Math.toIntExact(value);
1247     }
1248 
1249     /**
1250      * Returns the exact mathematical product of the arguments.
1251      *
1252      * @param x the first value
1253      * @param y the second value
1254      * @return the result
1255      * @see Math#multiplyFull(int,int)
1256      * @since 9
1257      */
multiplyFull(int x, int y)1258     public static long multiplyFull(int x, int y) {
1259         return Math.multiplyFull(x, y);
1260     }
1261 
1262     /**
1263      * Returns as a {@code long} the most significant 64 bits of the 128-bit
1264      * product of two 64-bit factors.
1265      *
1266      * @param x the first value
1267      * @param y the second value
1268      * @return the result
1269      * @see #unsignedMultiplyHigh
1270      * @see Math#multiplyHigh(long,long)
1271      * @since 9
1272      */
multiplyHigh(long x, long y)1273     public static long multiplyHigh(long x, long y) {
1274         return Math.multiplyHigh(x, y);
1275     }
1276 
1277     /**
1278      * Returns as a {@code long} the most significant 64 bits of the unsigned
1279      * 128-bit product of two unsigned 64-bit factors.
1280      *
1281      * @param x the first value
1282      * @param y the second value
1283      * @return the result
1284      * @see #multiplyHigh
1285      * @see Math#unsignedMultiplyHigh(long,long)
1286      * @since 18
1287      */
unsignedMultiplyHigh(long x, long y)1288     public static long unsignedMultiplyHigh(long x, long y) {
1289         return Math.unsignedMultiplyHigh(x, y);
1290     }
1291 
1292     /**
1293      * Returns the largest (closest to positive infinity)
1294      * {@code int} value that is less than or equal to the algebraic quotient.
1295      * There is one special case: if the dividend is
1296      * {@linkplain Integer#MIN_VALUE Integer.MIN_VALUE} and the divisor is {@code -1},
1297      * then integer overflow occurs and
1298      * the result is equal to {@code Integer.MIN_VALUE}.
1299      * <p>
1300      * See {@link Math#floorDiv(int, int) Math.floorDiv} for examples and
1301      * a comparison to the integer division {@code /} operator.
1302      *
1303      * @param x the dividend
1304      * @param y the divisor
1305      * @return the largest (closest to positive infinity)
1306      * {@code int} value that is less than or equal to the algebraic quotient.
1307      * @throws ArithmeticException if the divisor {@code y} is zero
1308      * @see Math#floorDiv(int, int)
1309      * @see Math#floor(double)
1310      * @since 1.8
1311      */
floorDiv(int x, int y)1312     public static int floorDiv(int x, int y) {
1313         return Math.floorDiv(x, y);
1314     }
1315 
1316     /**
1317      * Returns the largest (closest to positive infinity)
1318      * {@code long} value that is less than or equal to the algebraic quotient.
1319      * There is one special case: if the dividend is
1320      * {@linkplain Long#MIN_VALUE Long.MIN_VALUE} and the divisor is {@code -1},
1321      * then integer overflow occurs and
1322      * the result is equal to {@code Long.MIN_VALUE}.
1323      * <p>
1324      * See {@link Math#floorDiv(int, int) Math.floorDiv} for examples and
1325      * a comparison to the integer division {@code /} operator.
1326      *
1327      * @param x the dividend
1328      * @param y the divisor
1329      * @return the largest (closest to positive infinity)
1330      * {@code long} value that is less than or equal to the algebraic quotient.
1331      * @throws ArithmeticException if the divisor {@code y} is zero
1332      * @see Math#floorDiv(long, int)
1333      * @see Math#floor(double)
1334      * @since 9
1335      */
floorDiv(long x, int y)1336     public static long floorDiv(long x, int y) {
1337         return Math.floorDiv(x, y);
1338     }
1339 
1340     /**
1341      * Returns the largest (closest to positive infinity)
1342      * {@code long} value that is less than or equal to the algebraic quotient.
1343      * There is one special case: if the dividend is
1344      * {@linkplain Long#MIN_VALUE Long.MIN_VALUE} and the divisor is {@code -1},
1345      * then integer overflow occurs and
1346      * the result is equal to {@code Long.MIN_VALUE}.
1347      * <p>
1348      * See {@link Math#floorDiv(int, int) Math.floorDiv} for examples and
1349      * a comparison to the integer division {@code /} operator.
1350      *
1351      * @param x the dividend
1352      * @param y the divisor
1353      * @return the largest (closest to positive infinity)
1354      * {@code long} value that is less than or equal to the algebraic quotient.
1355      * @throws ArithmeticException if the divisor {@code y} is zero
1356      * @see Math#floorDiv(long, long)
1357      * @see Math#floor(double)
1358      * @since 1.8
1359      */
floorDiv(long x, long y)1360     public static long floorDiv(long x, long y) {
1361         return Math.floorDiv(x, y);
1362     }
1363 
1364     /**
1365      * Returns the floor modulus of the {@code int} arguments.
1366      * <p>
1367      * The floor modulus is {@code r = x - (floorDiv(x, y) * y)},
1368      * has the same sign as the divisor {@code y} or is zero, and
1369      * is in the range of {@code -abs(y) < r < +abs(y)}.
1370      *
1371      * <p>
1372      * The relationship between {@code floorDiv} and {@code floorMod} is such that:
1373      * <ul>
1374      *   <li>{@code floorDiv(x, y) * y + floorMod(x, y) == x}</li>
1375      * </ul>
1376      * <p>
1377      * See {@link Math#floorMod(int, int) Math.floorMod} for examples and
1378      * a comparison to the {@code %} operator.
1379      *
1380      * @param x the dividend
1381      * @param y the divisor
1382      * @return the floor modulus {@code x - (floorDiv(x, y) * y)}
1383      * @throws ArithmeticException if the divisor {@code y} is zero
1384      * @see Math#floorMod(int, int)
1385      * @see StrictMath#floorDiv(int, int)
1386      * @since 1.8
1387      */
floorMod(int x, int y)1388     public static int floorMod(int x, int y) {
1389         return Math.floorMod(x , y);
1390     }
1391 
1392     /**
1393      * Returns the floor modulus of the {@code long} and {@code int} arguments.
1394      * <p>
1395      * The floor modulus is {@code r = x - (floorDiv(x, y) * y)},
1396      * has the same sign as the divisor {@code y} or is zero, and
1397      * is in the range of {@code -abs(y) < r < +abs(y)}.
1398      *
1399      * <p>
1400      * The relationship between {@code floorDiv} and {@code floorMod} is such that:
1401      * <ul>
1402      *   <li>{@code floorDiv(x, y) * y + floorMod(x, y) == x}</li>
1403      * </ul>
1404      * <p>
1405      * See {@link Math#floorMod(int, int) Math.floorMod} for examples and
1406      * a comparison to the {@code %} operator.
1407      *
1408      * @param x the dividend
1409      * @param y the divisor
1410      * @return the floor modulus {@code x - (floorDiv(x, y) * y)}
1411      * @throws ArithmeticException if the divisor {@code y} is zero
1412      * @see Math#floorMod(long, int)
1413      * @see StrictMath#floorDiv(long, int)
1414      * @since 9
1415      */
floorMod(long x, int y)1416     public static int floorMod(long x, int y) {
1417         return Math.floorMod(x , y);
1418     }
1419 
1420     /**
1421      * Returns the floor modulus of the {@code long} arguments.
1422      * <p>
1423      * The floor modulus is {@code r = x - (floorDiv(x, y) * y)},
1424      * has the same sign as the divisor {@code y} or is zero, and
1425      * is in the range of {@code -abs(y) < r < +abs(y)}.
1426      *
1427      * <p>
1428      * The relationship between {@code floorDiv} and {@code floorMod} is such that:
1429      * <ul>
1430      *   <li>{@code floorDiv(x, y) * y + floorMod(x, y) == x}</li>
1431      * </ul>
1432      * <p>
1433      * See {@link Math#floorMod(int, int) Math.floorMod} for examples and
1434      * a comparison to the {@code %} operator.
1435      *
1436      * @param x the dividend
1437      * @param y the divisor
1438      * @return the floor modulus {@code x - (floorDiv(x, y) * y)}
1439      * @throws ArithmeticException if the divisor {@code y} is zero
1440      * @see Math#floorMod(long, long)
1441      * @see StrictMath#floorDiv(long, long)
1442      * @since 1.8
1443      */
floorMod(long x, long y)1444     public static long floorMod(long x, long y) {
1445         return Math.floorMod(x, y);
1446     }
1447 
1448     /**
1449      * Returns the smallest (closest to negative infinity)
1450      * {@code int} value that is greater than or equal to the algebraic quotient.
1451      * There is one special case: if the dividend is
1452      * {@linkplain Integer#MIN_VALUE Integer.MIN_VALUE} and the divisor is {@code -1},
1453      * then integer overflow occurs and
1454      * the result is equal to {@code Integer.MIN_VALUE}.
1455      * <p>
1456      * See {@link Math#ceilDiv(int, int) Math.ceilDiv} for examples and
1457      * a comparison to the integer division {@code /} operator.
1458      *
1459      * @param x the dividend
1460      * @param y the divisor
1461      * @return the smallest (closest to negative infinity)
1462      * {@code int} value that is greater than or equal to the algebraic quotient.
1463      * @throws ArithmeticException if the divisor {@code y} is zero
1464      * @see Math#ceilDiv(int, int)
1465      * @see Math#ceil(double)
1466      * @since 18
1467      */
ceilDiv(int x, int y)1468     public static int ceilDiv(int x, int y) {
1469         return Math.ceilDiv(x, y);
1470     }
1471 
1472     /**
1473      * Returns the smallest (closest to negative infinity)
1474      * {@code long} value that is greater than or equal to the algebraic quotient.
1475      * There is one special case: if the dividend is
1476      * {@linkplain Long#MIN_VALUE Long.MIN_VALUE} and the divisor is {@code -1},
1477      * then integer overflow occurs and
1478      * the result is equal to {@code Long.MIN_VALUE}.
1479      * <p>
1480      * See {@link Math#ceilDiv(int, int) Math.ceilDiv} for examples and
1481      * a comparison to the integer division {@code /} operator.
1482      *
1483      * @param x the dividend
1484      * @param y the divisor
1485      * @return the smallest (closest to negative infinity)
1486      * {@code long} value that is greater than or equal to the algebraic quotient.
1487      * @throws ArithmeticException if the divisor {@code y} is zero
1488      * @see Math#ceilDiv(long, int)
1489      * @see Math#ceil(double)
1490      * @since 18
1491      */
ceilDiv(long x, int y)1492     public static long ceilDiv(long x, int y) {
1493         return Math.ceilDiv(x, y);
1494     }
1495 
1496     /**
1497      * Returns the smallest (closest to negative infinity)
1498      * {@code long} value that is greater than or equal to the algebraic quotient.
1499      * There is one special case: if the dividend is
1500      * {@linkplain Long#MIN_VALUE Long.MIN_VALUE} and the divisor is {@code -1},
1501      * then integer overflow occurs and
1502      * the result is equal to {@code Long.MIN_VALUE}.
1503      * <p>
1504      * See {@link Math#ceilDiv(int, int) Math.ceilDiv} for examples and
1505      * a comparison to the integer division {@code /} operator.
1506      *
1507      * @param x the dividend
1508      * @param y the divisor
1509      * @return the smallest (closest to negative infinity)
1510      * {@code long} value that is greater than or equal to the algebraic quotient.
1511      * @throws ArithmeticException if the divisor {@code y} is zero
1512      * @see Math#ceilDiv(long, long)
1513      * @see Math#ceil(double)
1514      * @since 18
1515      */
ceilDiv(long x, long y)1516     public static long ceilDiv(long x, long y) {
1517         return Math.ceilDiv(x, y);
1518     }
1519 
1520     /**
1521      * Returns the ceiling modulus of the {@code int} arguments.
1522      * <p>
1523      * The ceiling modulus is {@code r = x - (ceilDiv(x, y) * y)},
1524      * has the opposite sign as the divisor {@code y} or is zero, and
1525      * is in the range of {@code -abs(y) < r < +abs(y)}.
1526      *
1527      * <p>
1528      * The relationship between {@code ceilDiv} and {@code ceilMod} is such that:
1529      * <ul>
1530      *   <li>{@code ceilDiv(x, y) * y + ceilMod(x, y) == x}</li>
1531      * </ul>
1532      * <p>
1533      * See {@link Math#ceilMod(int, int) Math.ceilMod} for examples and
1534      * a comparison to the {@code %} operator.
1535      *
1536      * @param x the dividend
1537      * @param y the divisor
1538      * @return the ceiling modulus {@code x - (ceilDiv(x, y) * y)}
1539      * @throws ArithmeticException if the divisor {@code y} is zero
1540      * @see Math#ceilMod(int, int)
1541      * @see StrictMath#ceilDiv(int, int)
1542      * @since 18
1543      */
ceilMod(int x, int y)1544     public static int ceilMod(int x, int y) {
1545         return Math.ceilMod(x , y);
1546     }
1547 
1548     /**
1549      * Returns the ceiling modulus of the {@code long} and {@code int} arguments.
1550      * <p>
1551      * The ceiling modulus is {@code r = x - (ceilDiv(x, y) * y)},
1552      * has the opposite sign as the divisor {@code y} or is zero, and
1553      * is in the range of {@code -abs(y) < r < +abs(y)}.
1554      *
1555      * <p>
1556      * The relationship between {@code ceilDiv} and {@code ceilMod} is such that:
1557      * <ul>
1558      *   <li>{@code ceilDiv(x, y) * y + ceilMod(x, y) == x}</li>
1559      * </ul>
1560      * <p>
1561      * See {@link Math#ceilMod(int, int) Math.ceilMod} for examples and
1562      * a comparison to the {@code %} operator.
1563      *
1564      * @param x the dividend
1565      * @param y the divisor
1566      * @return the ceiling modulus {@code x - (ceilDiv(x, y) * y)}
1567      * @throws ArithmeticException if the divisor {@code y} is zero
1568      * @see Math#ceilMod(long, int)
1569      * @see StrictMath#ceilDiv(long, int)
1570      * @since 18
1571      */
ceilMod(long x, int y)1572     public static int ceilMod(long x, int y) {
1573         return Math.ceilMod(x , y);
1574     }
1575 
1576     /**
1577      * Returns the ceiling modulus of the {@code long} arguments.
1578      * <p>
1579      * The ceiling modulus is {@code r = x - (ceilDiv(x, y) * y)},
1580      * has the opposite sign as the divisor {@code y} or is zero, and
1581      * is in the range of {@code -abs(y) < r < +abs(y)}.
1582      *
1583      * <p>
1584      * The relationship between {@code ceilDiv} and {@code ceilMod} is such that:
1585      * <ul>
1586      *   <li>{@code ceilDiv(x, y) * y + ceilMod(x, y) == x}</li>
1587      * </ul>
1588      * <p>
1589      * See {@link Math#ceilMod(int, int) Math.ceilMod} for examples and
1590      * a comparison to the {@code %} operator.
1591      *
1592      * @param x the dividend
1593      * @param y the divisor
1594      * @return the ceiling modulus {@code x - (ceilDiv(x, y) * y)}
1595      * @throws ArithmeticException if the divisor {@code y} is zero
1596      * @see Math#ceilMod(long, long)
1597      * @see StrictMath#ceilDiv(long, long)
1598      * @since 18
1599      */
ceilMod(long x, long y)1600     public static long ceilMod(long x, long y) {
1601         return Math.ceilMod(x, y);
1602     }
1603 
1604     /**
1605      * Returns the absolute value of an {@code int} value.
1606      * If the argument is not negative, the argument is returned.
1607      * If the argument is negative, the negation of the argument is returned.
1608      *
1609      * <p>Note that if the argument is equal to the value of {@link
1610      * Integer#MIN_VALUE}, the most negative representable {@code int}
1611      * value, the result is that same value, which is negative. In
1612      * contrast, the {@link StrictMath#absExact(int)} method throws an
1613      * {@code ArithmeticException} for this value.
1614      *
1615      * @param   a   the  argument whose absolute value is to be determined.
1616      * @return  the absolute value of the argument.
1617      * @see Math#absExact(int)
1618      */
abs(int a)1619     public static int abs(int a) {
1620         return Math.abs(a);
1621     }
1622 
1623     /**
1624      * Returns the mathematical absolute value of an {@code int} value
1625      * if it is exactly representable as an {@code int}, throwing
1626      * {@code ArithmeticException} if the result overflows the
1627      * positive {@code int} range.
1628      *
1629      * <p>Since the range of two's complement integers is asymmetric
1630      * with one additional negative value (JLS {@jls 4.2.1}), the
1631      * mathematical absolute value of {@link Integer#MIN_VALUE}
1632      * overflows the positive {@code int} range, so an exception is
1633      * thrown for that argument.
1634      *
1635      * @param  a  the argument whose absolute value is to be determined
1636      * @return the absolute value of the argument, unless overflow occurs
1637      * @throws ArithmeticException if the argument is {@link Integer#MIN_VALUE}
1638      * @see Math#abs(int)
1639      * @see Math#absExact(int)
1640      * @since 15
1641      */
absExact(int a)1642     public static int absExact(int a) {
1643         return Math.absExact(a);
1644     }
1645 
1646     /**
1647      * Returns the absolute value of a {@code long} value.
1648      * If the argument is not negative, the argument is returned.
1649      * If the argument is negative, the negation of the argument is returned.
1650      *
1651      * <p>Note that if the argument is equal to the value of {@link
1652      * Long#MIN_VALUE}, the most negative representable {@code long}
1653      * value, the result is that same value, which is negative. In
1654      * contrast, the {@link StrictMath#absExact(long)} method throws
1655      * an {@code ArithmeticException} for this value.
1656      *
1657      * @param   a   the  argument whose absolute value is to be determined.
1658      * @return  the absolute value of the argument.
1659      * @see Math#absExact(long)
1660      */
abs(long a)1661     public static long abs(long a) {
1662         return Math.abs(a);
1663     }
1664 
1665     /**
1666      * Returns the mathematical absolute value of an {@code long} value
1667      * if it is exactly representable as an {@code long}, throwing
1668      * {@code ArithmeticException} if the result overflows the
1669      * positive {@code long} range.
1670      *
1671      * <p>Since the range of two's complement integers is asymmetric
1672      * with one additional negative value (JLS {@jls 4.2.1}), the
1673      * mathematical absolute value of {@link Long#MIN_VALUE} overflows
1674      * the positive {@code long} range, so an exception is thrown for
1675      * that argument.
1676      *
1677      * @param  a  the argument whose absolute value is to be determined
1678      * @return the absolute value of the argument, unless overflow occurs
1679      * @throws ArithmeticException if the argument is {@link Long#MIN_VALUE}
1680      * @see Math#abs(long)
1681      * @see Math#absExact(long)
1682      * @since 15
1683      */
absExact(long a)1684     public static long absExact(long a) {
1685         return Math.absExact(a);
1686     }
1687 
1688     /**
1689      * Returns the absolute value of a {@code float} value.
1690      * If the argument is not negative, the argument is returned.
1691      * If the argument is negative, the negation of the argument is returned.
1692      * Special cases:
1693      * <ul><li>If the argument is positive zero or negative zero, the
1694      * result is positive zero.
1695      * <li>If the argument is infinite, the result is positive infinity.
1696      * <li>If the argument is NaN, the result is NaN.</ul>
1697      *
1698      * @apiNote As implied by the above, one valid implementation of
1699      * this method is given by the expression below which computes a
1700      * {@code float} with the same exponent and significand as the
1701      * argument but with a guaranteed zero sign bit indicating a
1702      * positive value: <br>
1703      * {@code Float.intBitsToFloat(0x7fffffff & Float.floatToRawIntBits(a))}
1704      *
1705      * @param   a   the argument whose absolute value is to be determined
1706      * @return  the absolute value of the argument.
1707      */
abs(float a)1708     public static float abs(float a) {
1709         return Math.abs(a);
1710     }
1711 
1712     /**
1713      * Returns the absolute value of a {@code double} value.
1714      * If the argument is not negative, the argument is returned.
1715      * If the argument is negative, the negation of the argument is returned.
1716      * Special cases:
1717      * <ul><li>If the argument is positive zero or negative zero, the result
1718      * is positive zero.
1719      * <li>If the argument is infinite, the result is positive infinity.
1720      * <li>If the argument is NaN, the result is NaN.</ul>
1721      *
1722      * @apiNote As implied by the above, one valid implementation of
1723      * this method is given by the expression below which computes a
1724      * {@code double} with the same exponent and significand as the
1725      * argument but with a guaranteed zero sign bit indicating a
1726      * positive value: <br>
1727      * {@code Double.longBitsToDouble((Double.doubleToRawLongBits(a)<<1)>>>1)}
1728      *
1729      * @param   a   the argument whose absolute value is to be determined
1730      * @return  the absolute value of the argument.
1731      */
abs(double a)1732     public static double abs(double a) {
1733         return Math.abs(a);
1734     }
1735 
1736     /**
1737      * Returns the greater of two {@code int} values. That is, the
1738      * result is the argument closer to the value of
1739      * {@link Integer#MAX_VALUE}. If the arguments have the same value,
1740      * the result is that same value.
1741      *
1742      * @param   a   an argument.
1743      * @param   b   another argument.
1744      * @return  the larger of {@code a} and {@code b}.
1745      */
1746     @IntrinsicCandidate
max(int a, int b)1747     public static int max(int a, int b) {
1748         return Math.max(a, b);
1749     }
1750 
1751     /**
1752      * Returns the greater of two {@code long} values. That is, the
1753      * result is the argument closer to the value of
1754      * {@link Long#MAX_VALUE}. If the arguments have the same value,
1755      * the result is that same value.
1756      *
1757      * @param   a   an argument.
1758      * @param   b   another argument.
1759      * @return  the larger of {@code a} and {@code b}.
1760      */
max(long a, long b)1761     public static long max(long a, long b) {
1762         return Math.max(a, b);
1763     }
1764 
1765     /**
1766      * Returns the greater of two {@code float} values.  That is,
1767      * the result is the argument closer to positive infinity. If the
1768      * arguments have the same value, the result is that same
1769      * value. If either value is NaN, then the result is NaN.  Unlike
1770      * the numerical comparison operators, this method considers
1771      * negative zero to be strictly smaller than positive zero. If one
1772      * argument is positive zero and the other negative zero, the
1773      * result is positive zero.
1774      *
1775      * @param   a   an argument.
1776      * @param   b   another argument.
1777      * @return  the larger of {@code a} and {@code b}.
1778      */
1779     @IntrinsicCandidate
max(float a, float b)1780     public static float max(float a, float b) {
1781         return Math.max(a, b);
1782     }
1783 
1784     /**
1785      * Returns the greater of two {@code double} values.  That
1786      * is, the result is the argument closer to positive infinity. If
1787      * the arguments have the same value, the result is that same
1788      * value. If either value is NaN, then the result is NaN.  Unlike
1789      * the numerical comparison operators, this method considers
1790      * negative zero to be strictly smaller than positive zero. If one
1791      * argument is positive zero and the other negative zero, the
1792      * result is positive zero.
1793      *
1794      * @param   a   an argument.
1795      * @param   b   another argument.
1796      * @return  the larger of {@code a} and {@code b}.
1797      */
1798     @IntrinsicCandidate
max(double a, double b)1799     public static double max(double a, double b) {
1800         return Math.max(a, b);
1801     }
1802 
1803     /**
1804      * Returns the smaller of two {@code int} values. That is,
1805      * the result the argument closer to the value of
1806      * {@link Integer#MIN_VALUE}.  If the arguments have the same
1807      * value, the result is that same value.
1808      *
1809      * @param   a   an argument.
1810      * @param   b   another argument.
1811      * @return  the smaller of {@code a} and {@code b}.
1812      */
1813     @IntrinsicCandidate
min(int a, int b)1814     public static int min(int a, int b) {
1815         return Math.min(a, b);
1816     }
1817 
1818     /**
1819      * Returns the smaller of two {@code long} values. That is,
1820      * the result is the argument closer to the value of
1821      * {@link Long#MIN_VALUE}. If the arguments have the same
1822      * value, the result is that same value.
1823      *
1824      * @param   a   an argument.
1825      * @param   b   another argument.
1826      * @return  the smaller of {@code a} and {@code b}.
1827      */
min(long a, long b)1828     public static long min(long a, long b) {
1829         return Math.min(a, b);
1830     }
1831 
1832     /**
1833      * Returns the smaller of two {@code float} values.  That is,
1834      * the result is the value closer to negative infinity. If the
1835      * arguments have the same value, the result is that same
1836      * value. If either value is NaN, then the result is NaN.  Unlike
1837      * the numerical comparison operators, this method considers
1838      * negative zero to be strictly smaller than positive zero.  If
1839      * one argument is positive zero and the other is negative zero,
1840      * the result is negative zero.
1841      *
1842      * @param   a   an argument.
1843      * @param   b   another argument.
1844      * @return  the smaller of {@code a} and {@code b.}
1845      */
1846     @IntrinsicCandidate
min(float a, float b)1847     public static float min(float a, float b) {
1848         return Math.min(a, b);
1849     }
1850 
1851     /**
1852      * Returns the smaller of two {@code double} values.  That
1853      * is, the result is the value closer to negative infinity. If the
1854      * arguments have the same value, the result is that same
1855      * value. If either value is NaN, then the result is NaN.  Unlike
1856      * the numerical comparison operators, this method considers
1857      * negative zero to be strictly smaller than positive zero. If one
1858      * argument is positive zero and the other is negative zero, the
1859      * result is negative zero.
1860      *
1861      * @param   a   an argument.
1862      * @param   b   another argument.
1863      * @return  the smaller of {@code a} and {@code b}.
1864      */
1865     @IntrinsicCandidate
min(double a, double b)1866     public static double min(double a, double b) {
1867         return Math.min(a, b);
1868     }
1869 
1870     /**
1871      * Clamps the value to fit between min and max. If the value is less
1872      * than {@code min}, then {@code min} is returned. If the value is greater
1873      * than {@code max}, then {@code max} is returned. Otherwise, the original
1874      * value is returned.
1875      * <p>
1876      * While the original value of type long may not fit into the int type,
1877      * the bounds have the int type, so the result always fits the int type.
1878      * This allows to use method to safely cast long value to int with
1879      * saturation.
1880      *
1881      * @param value value to clamp
1882      * @param min minimal allowed value
1883      * @param max maximal allowed value
1884      * @return a clamped value that fits into {@code min..max} interval
1885      * @throws IllegalArgumentException if {@code min > max}
1886      *
1887      * @since 21
1888      */
clamp(long value, int min, int max)1889     public static int clamp(long value, int min, int max) {
1890         return Math.clamp(value, min, max);
1891     }
1892 
1893     /**
1894      * Clamps the value to fit between min and max. If the value is less
1895      * than {@code min}, then {@code min} is returned. If the value is greater
1896      * than {@code max}, then {@code max} is returned. Otherwise, the original
1897      * value is returned.
1898      *
1899      * @param value value to clamp
1900      * @param min minimal allowed value
1901      * @param max maximal allowed value
1902      * @return a clamped value that fits into {@code min..max} interval
1903      * @throws IllegalArgumentException if {@code min > max}
1904      *
1905      * @since 21
1906      */
clamp(long value, long min, long max)1907     public static long clamp(long value, long min, long max) {
1908         return Math.clamp(value, min, max);
1909     }
1910 
1911     /**
1912      * Clamps the value to fit between min and max. If the value is less
1913      * than {@code min}, then {@code min} is returned. If the value is greater
1914      * than {@code max}, then {@code max} is returned. Otherwise, the original
1915      * value is returned. If value is NaN, the result is also NaN.
1916      * <p>
1917      * Unlike the numerical comparison operators, this method considers
1918      * negative zero to be strictly smaller than positive zero.
1919      * E.g., {@code clamp(-0.0, 0.0, 1.0)} returns 0.0.
1920      *
1921      * @param value value to clamp
1922      * @param min minimal allowed value
1923      * @param max maximal allowed value
1924      * @return a clamped value that fits into {@code min..max} interval
1925      * @throws IllegalArgumentException if either of {@code min} and {@code max}
1926      * arguments is NaN, or {@code min > max}, or {@code min} is +0.0, and
1927      * {@code max} is -0.0.
1928      *
1929      * @since 21
1930      */
clamp(double value, double min, double max)1931     public static double clamp(double value, double min, double max) {
1932         return Math.clamp(value, min, max);
1933     }
1934 
1935     /**
1936      * Clamps the value to fit between min and max. If the value is less
1937      * than {@code min}, then {@code min} is returned. If the value is greater
1938      * than {@code max}, then {@code max} is returned. Otherwise, the original
1939      * value is returned. If value is NaN, the result is also NaN.
1940      * <p>
1941      * Unlike the numerical comparison operators, this method considers
1942      * negative zero to be strictly smaller than positive zero.
1943      * E.g., {@code clamp(-0.0f, 0.0f, 1.0f)} returns 0.0f.
1944      *
1945      * @param value value to clamp
1946      * @param min minimal allowed value
1947      * @param max maximal allowed value
1948      * @return a clamped value that fits into {@code min..max} interval
1949      * @throws IllegalArgumentException if either of {@code min} and {@code max}
1950      * arguments is NaN, or {@code min > max}, or {@code min} is +0.0f, and
1951      * {@code max} is -0.0f.
1952      *
1953      * @since 21
1954      */
clamp(float value, float min, float max)1955     public static float clamp(float value, float min, float max) {
1956         return Math.clamp(value, min, max);
1957     }
1958 
1959     /**
1960      * Returns the fused multiply add of the three arguments; that is,
1961      * returns the exact product of the first two arguments summed
1962      * with the third argument and then rounded once to the nearest
1963      * {@code double}.
1964      *
1965      * The rounding is done using the {@linkplain
1966      * java.math.RoundingMode#HALF_EVEN round to nearest even
1967      * rounding mode}.
1968      *
1969      * In contrast, if {@code a * b + c} is evaluated as a regular
1970      * floating-point expression, two rounding errors are involved,
1971      * the first for the multiply operation, the second for the
1972      * addition operation.
1973      *
1974      * <p>Special cases:
1975      * <ul>
1976      * <li> If any argument is NaN, the result is NaN.
1977      *
1978      * <li> If one of the first two arguments is infinite and the
1979      * other is zero, the result is NaN.
1980      *
1981      * <li> If the exact product of the first two arguments is infinite
1982      * (in other words, at least one of the arguments is infinite and
1983      * the other is neither zero nor NaN) and the third argument is an
1984      * infinity of the opposite sign, the result is NaN.
1985      *
1986      * </ul>
1987      *
1988      * <p>Note that {@code fusedMac(a, 1.0, c)} returns the same
1989      * result as ({@code a + c}).  However,
1990      * {@code fusedMac(a, b, +0.0)} does <em>not</em> always return the
1991      * same result as ({@code a * b}) since
1992      * {@code fusedMac(-0.0, +0.0, +0.0)} is {@code +0.0} while
1993      * ({@code -0.0 * +0.0}) is {@code -0.0}; {@code fusedMac(a, b, -0.0)} is
1994      * equivalent to ({@code a * b}) however.
1995      *
1996      * @apiNote This method corresponds to the fusedMultiplyAdd
1997      * operation defined in IEEE 754-2008.
1998      *
1999      * @param a a value
2000      * @param b a value
2001      * @param c a value
2002      *
2003      * @return (<i>a</i>&nbsp;&times;&nbsp;<i>b</i>&nbsp;+&nbsp;<i>c</i>)
2004      * computed, as if with unlimited range and precision, and rounded
2005      * once to the nearest {@code double} value
2006      *
2007      * @since 9
2008      */
fma(double a, double b, double c)2009     public static double fma(double a, double b, double c) {
2010         return Math.fma(a, b, c);
2011     }
2012 
2013     /**
2014      * Returns the fused multiply add of the three arguments; that is,
2015      * returns the exact product of the first two arguments summed
2016      * with the third argument and then rounded once to the nearest
2017      * {@code float}.
2018      *
2019      * The rounding is done using the {@linkplain
2020      * java.math.RoundingMode#HALF_EVEN round to nearest even
2021      * rounding mode}.
2022      *
2023      * In contrast, if {@code a * b + c} is evaluated as a regular
2024      * floating-point expression, two rounding errors are involved,
2025      * the first for the multiply operation, the second for the
2026      * addition operation.
2027      *
2028      * <p>Special cases:
2029      * <ul>
2030      * <li> If any argument is NaN, the result is NaN.
2031      *
2032      * <li> If one of the first two arguments is infinite and the
2033      * other is zero, the result is NaN.
2034      *
2035      * <li> If the exact product of the first two arguments is infinite
2036      * (in other words, at least one of the arguments is infinite and
2037      * the other is neither zero nor NaN) and the third argument is an
2038      * infinity of the opposite sign, the result is NaN.
2039      *
2040      * </ul>
2041      *
2042      * <p>Note that {@code fma(a, 1.0f, c)} returns the same
2043      * result as ({@code a + c}).  However,
2044      * {@code fma(a, b, +0.0f)} does <em>not</em> always return the
2045      * same result as ({@code a * b}) since
2046      * {@code fma(-0.0f, +0.0f, +0.0f)} is {@code +0.0f} while
2047      * ({@code -0.0f * +0.0f}) is {@code -0.0f}; {@code fma(a, b, -0.0f)} is
2048      * equivalent to ({@code a * b}) however.
2049      *
2050      * @apiNote This method corresponds to the fusedMultiplyAdd
2051      * operation defined in IEEE 754-2008.
2052      *
2053      * @param a a value
2054      * @param b a value
2055      * @param c a value
2056      *
2057      * @return (<i>a</i>&nbsp;&times;&nbsp;<i>b</i>&nbsp;+&nbsp;<i>c</i>)
2058      * computed, as if with unlimited range and precision, and rounded
2059      * once to the nearest {@code float} value
2060      *
2061      * @since 9
2062      */
fma(float a, float b, float c)2063     public static float fma(float a, float b, float c) {
2064         return Math.fma(a, b, c);
2065     }
2066 
2067     /**
2068      * Returns the size of an ulp of the argument.  An ulp, unit in
2069      * the last place, of a {@code double} value is the positive
2070      * distance between this floating-point value and the {@code
2071      * double} value next larger in magnitude.  Note that for non-NaN
2072      * <i>x</i>, <code>ulp(-<i>x</i>) == ulp(<i>x</i>)</code>.
2073      *
2074      * <p>Special Cases:
2075      * <ul>
2076      * <li> If the argument is NaN, then the result is NaN.
2077      * <li> If the argument is positive or negative infinity, then the
2078      * result is positive infinity.
2079      * <li> If the argument is positive or negative zero, then the result is
2080      * {@code Double.MIN_VALUE}.
2081      * <li> If the argument is &plusmn;{@code Double.MAX_VALUE}, then
2082      * the result is equal to 2<sup>971</sup>.
2083      * </ul>
2084      *
2085      * @param d the floating-point value whose ulp is to be returned
2086      * @return the size of an ulp of the argument
2087      * @author Joseph D. Darcy
2088      * @since 1.5
2089      */
ulp(double d)2090     public static double ulp(double d) {
2091         return Math.ulp(d);
2092     }
2093 
2094     /**
2095      * Returns the size of an ulp of the argument.  An ulp, unit in
2096      * the last place, of a {@code float} value is the positive
2097      * distance between this floating-point value and the {@code
2098      * float} value next larger in magnitude.  Note that for non-NaN
2099      * <i>x</i>, <code>ulp(-<i>x</i>) == ulp(<i>x</i>)</code>.
2100      *
2101      * <p>Special Cases:
2102      * <ul>
2103      * <li> If the argument is NaN, then the result is NaN.
2104      * <li> If the argument is positive or negative infinity, then the
2105      * result is positive infinity.
2106      * <li> If the argument is positive or negative zero, then the result is
2107      * {@code Float.MIN_VALUE}.
2108      * <li> If the argument is &plusmn;{@code Float.MAX_VALUE}, then
2109      * the result is equal to 2<sup>104</sup>.
2110      * </ul>
2111      *
2112      * @param f the floating-point value whose ulp is to be returned
2113      * @return the size of an ulp of the argument
2114      * @author Joseph D. Darcy
2115      * @since 1.5
2116      */
ulp(float f)2117     public static float ulp(float f) {
2118         return Math.ulp(f);
2119     }
2120 
2121     /**
2122      * Returns the signum function of the argument; zero if the argument
2123      * is zero, 1.0 if the argument is greater than zero, -1.0 if the
2124      * argument is less than zero.
2125      *
2126      * <p>Special Cases:
2127      * <ul>
2128      * <li> If the argument is NaN, then the result is NaN.
2129      * <li> If the argument is positive zero or negative zero, then the
2130      *      result is the same as the argument.
2131      * </ul>
2132      *
2133      * @param d the floating-point value whose signum is to be returned
2134      * @return the signum function of the argument
2135      * @author Joseph D. Darcy
2136      * @since 1.5
2137      */
signum(double d)2138     public static double signum(double d) {
2139         return Math.signum(d);
2140     }
2141 
2142     /**
2143      * Returns the signum function of the argument; zero if the argument
2144      * is zero, 1.0f if the argument is greater than zero, -1.0f if the
2145      * argument is less than zero.
2146      *
2147      * <p>Special Cases:
2148      * <ul>
2149      * <li> If the argument is NaN, then the result is NaN.
2150      * <li> If the argument is positive zero or negative zero, then the
2151      *      result is the same as the argument.
2152      * </ul>
2153      *
2154      * @param f the floating-point value whose signum is to be returned
2155      * @return the signum function of the argument
2156      * @author Joseph D. Darcy
2157      * @since 1.5
2158      */
signum(float f)2159     public static float signum(float f) {
2160         return Math.signum(f);
2161     }
2162 
2163     /**
2164      * Returns the hyperbolic sine of a {@code double} value.
2165      * The hyperbolic sine of <i>x</i> is defined to be
2166      * (<i>e<sup>x</sup>&nbsp;-&nbsp;e<sup>-x</sup></i>)/2
2167      * where <i>e</i> is {@linkplain Math#E Euler's number}.
2168      *
2169      * <p>Special cases:
2170      * <ul>
2171      *
2172      * <li>If the argument is NaN, then the result is NaN.
2173      *
2174      * <li>If the argument is infinite, then the result is an infinity
2175      * with the same sign as the argument.
2176      *
2177      * <li>If the argument is zero, then the result is a zero with the
2178      * same sign as the argument.
2179      *
2180      * </ul>
2181      *
2182      * @param   x The number whose hyperbolic sine is to be returned.
2183      * @return  The hyperbolic sine of {@code x}.
2184      * @since 1.5
2185      */
2186     // Android-changed: Reimplement in native
2187     // public static double sinh(double x) {
2188     //     return FdLibm.Sinh.compute(x);
2189     // }
2190     @CriticalNative
sinh(double x)2191     public static native double sinh(double x);
2192 
2193     /**
2194      * Returns the hyperbolic cosine of a {@code double} value.
2195      * The hyperbolic cosine of <i>x</i> is defined to be
2196      * (<i>e<sup>x</sup>&nbsp;+&nbsp;e<sup>-x</sup></i>)/2
2197      * where <i>e</i> is {@linkplain Math#E Euler's number}.
2198      *
2199      * <p>Special cases:
2200      * <ul>
2201      *
2202      * <li>If the argument is NaN, then the result is NaN.
2203      *
2204      * <li>If the argument is infinite, then the result is positive
2205      * infinity.
2206      *
2207      * <li>If the argument is zero, then the result is {@code 1.0}.
2208      *
2209      * </ul>
2210      *
2211      * @param   x The number whose hyperbolic cosine is to be returned.
2212      * @return  The hyperbolic cosine of {@code x}.
2213      * @since 1.5
2214      */
2215     // Android-changed: Reimplement in native
2216     // public static double cosh(double x) {
2217     //     return FdLibm.Cosh.compute(x);
2218     // }
2219     @CriticalNative
cosh(double x)2220     public static native double cosh(double x);
2221 
2222     /**
2223      * Returns the hyperbolic tangent of a {@code double} value.
2224      * The hyperbolic tangent of <i>x</i> is defined to be
2225      * (<i>e<sup>x</sup>&nbsp;-&nbsp;e<sup>-x</sup></i>)/(<i>e<sup>x</sup>&nbsp;+&nbsp;e<sup>-x</sup></i>),
2226      * in other words, {@linkplain Math#sinh
2227      * sinh(<i>x</i>)}/{@linkplain Math#cosh cosh(<i>x</i>)}.  Note
2228      * that the absolute value of the exact tanh is always less than
2229      * 1.
2230      *
2231      * <p>Special cases:
2232      * <ul>
2233      *
2234      * <li>If the argument is NaN, then the result is NaN.
2235      *
2236      * <li>If the argument is zero, then the result is a zero with the
2237      * same sign as the argument.
2238      *
2239      * <li>If the argument is positive infinity, then the result is
2240      * {@code +1.0}.
2241      *
2242      * <li>If the argument is negative infinity, then the result is
2243      * {@code -1.0}.
2244      *
2245      * </ul>
2246      *
2247      * @param   x The number whose hyperbolic tangent is to be returned.
2248      * @return  The hyperbolic tangent of {@code x}.
2249      * @since 1.5
2250      */
2251     // Android-changed: Reimplement in native
2252     // public static double tanh(double x) {
2253     //     return FdLibm.Tanh.compute(x);
2254     // }
2255     @CriticalNative
tanh(double x)2256     public static native double tanh(double x);
2257 
2258     /**
2259      * Returns sqrt(<i>x</i><sup>2</sup>&nbsp;+<i>y</i><sup>2</sup>)
2260      * without intermediate overflow or underflow.
2261      *
2262      * <p>Special cases:
2263      * <ul>
2264      *
2265      * <li> If either argument is infinite, then the result
2266      * is positive infinity.
2267      *
2268      * <li> If either argument is NaN and neither argument is infinite,
2269      * then the result is NaN.
2270      *
2271      * <li> If both arguments are zero, the result is positive zero.
2272      * </ul>
2273      *
2274      * @param x a value
2275      * @param y a value
2276      * @return sqrt(<i>x</i><sup>2</sup>&nbsp;+<i>y</i><sup>2</sup>)
2277      * without intermediate overflow or underflow
2278      * @since 1.5
2279      */
2280     // BEGIN Android-changed: Reimplement in native
2281     /*
2282     public static double hypot(double x, double y) {
2283         return FdLibm.Hypot.compute(x, y);
2284     }
2285     */
2286     // END Android-changed: Reimplement in native
2287     @CriticalNative
hypot(double x, double y)2288     public static native double hypot(double x, double y);
2289 
2290     /**
2291      * Returns <i>e</i><sup>x</sup>&nbsp;-1.  Note that for values of
2292      * <i>x</i> near 0, the exact sum of
2293      * {@code expm1(x)}&nbsp;+&nbsp;1 is much closer to the true
2294      * result of <i>e</i><sup>x</sup> than {@code exp(x)}.
2295      *
2296      * <p>Special cases:
2297      * <ul>
2298      * <li>If the argument is NaN, the result is NaN.
2299      *
2300      * <li>If the argument is positive infinity, then the result is
2301      * positive infinity.
2302      *
2303      * <li>If the argument is negative infinity, then the result is
2304      * -1.0.
2305      *
2306      * <li>If the argument is zero, then the result is a zero with the
2307      * same sign as the argument.
2308      *
2309      * </ul>
2310      *
2311      * @param   x   the exponent to raise <i>e</i> to in the computation of
2312      *              <i>e</i><sup>{@code x}</sup>&nbsp;-1.
2313      * @return  the value <i>e</i><sup>{@code x}</sup>&nbsp;-&nbsp;1.
2314      * @since 1.5
2315      */
2316     // Android-changed: Reimplement in native
2317     // public static double expm1(double x) {
2318     //     return FdLibm.Expm1.compute(x);
2319     // }
2320     @CriticalNative
expm1(double x)2321     public static native double expm1(double x);
2322 
2323     /**
2324      * Returns the natural logarithm of the sum of the argument and 1.
2325      * Note that for small values {@code x}, the result of
2326      * {@code log1p(x)} is much closer to the true result of ln(1
2327      * + {@code x}) than the floating-point evaluation of
2328      * {@code log(1.0+x)}.
2329      *
2330      * <p>Special cases:
2331      * <ul>
2332      *
2333      * <li>If the argument is NaN or less than -1, then the result is
2334      * NaN.
2335      *
2336      * <li>If the argument is positive infinity, then the result is
2337      * positive infinity.
2338      *
2339      * <li>If the argument is negative one, then the result is
2340      * negative infinity.
2341      *
2342      * <li>If the argument is zero, then the result is a zero with the
2343      * same sign as the argument.
2344      *
2345      * </ul>
2346      *
2347      * @param   x   a value
2348      * @return the value ln({@code x}&nbsp;+&nbsp;1), the natural
2349      * log of {@code x}&nbsp;+&nbsp;1
2350      * @since 1.5
2351      */
2352     // Android-changed: Reimplement in native
2353     // public static double log1p(double x) {
2354     //     return FdLibm.Log1p.compute(x);
2355     // }
2356     @CriticalNative
log1p(double x)2357     public static native double log1p(double x);
2358 
2359     /**
2360      * Returns the first floating-point argument with the sign of the
2361      * second floating-point argument.  For this method, a NaN
2362      * {@code sign} argument is always treated as if it were
2363      * positive.
2364      *
2365      * @param magnitude  the parameter providing the magnitude of the result
2366      * @param sign   the parameter providing the sign of the result
2367      * @return a value with the magnitude of {@code magnitude}
2368      * and the sign of {@code sign}.
2369      * @since 1.6
2370      */
copySign(double magnitude, double sign)2371     public static double copySign(double magnitude, double sign) {
2372         return Math.copySign(magnitude, (Double.isNaN(sign)?1.0d:sign));
2373     }
2374 
2375     /**
2376      * Returns the first floating-point argument with the sign of the
2377      * second floating-point argument.  For this method, a NaN
2378      * {@code sign} argument is always treated as if it were
2379      * positive.
2380      *
2381      * @param magnitude  the parameter providing the magnitude of the result
2382      * @param sign   the parameter providing the sign of the result
2383      * @return a value with the magnitude of {@code magnitude}
2384      * and the sign of {@code sign}.
2385      * @since 1.6
2386      */
copySign(float magnitude, float sign)2387     public static float copySign(float magnitude, float sign) {
2388         return Math.copySign(magnitude, (Float.isNaN(sign)?1.0f:sign));
2389     }
2390     /**
2391      * Returns the unbiased exponent used in the representation of a
2392      * {@code float}.  Special cases:
2393      *
2394      * <ul>
2395      * <li>If the argument is NaN or infinite, then the result is
2396      * {@link Float#MAX_EXPONENT} + 1.
2397      * <li>If the argument is zero or subnormal, then the result is
2398      * {@link Float#MIN_EXPONENT} -1.
2399      * </ul>
2400      * @param f a {@code float} value
2401      * @return the unbiased exponent of the argument
2402      * @since 1.6
2403      */
getExponent(float f)2404     public static int getExponent(float f) {
2405         return Math.getExponent(f);
2406     }
2407 
2408     /**
2409      * Returns the unbiased exponent used in the representation of a
2410      * {@code double}.  Special cases:
2411      *
2412      * <ul>
2413      * <li>If the argument is NaN or infinite, then the result is
2414      * {@link Double#MAX_EXPONENT} + 1.
2415      * <li>If the argument is zero or subnormal, then the result is
2416      * {@link Double#MIN_EXPONENT} -1.
2417      * </ul>
2418      * @param d a {@code double} value
2419      * @return the unbiased exponent of the argument
2420      * @since 1.6
2421      */
getExponent(double d)2422     public static int getExponent(double d) {
2423         return Math.getExponent(d);
2424     }
2425 
2426     /**
2427      * Returns the floating-point number adjacent to the first
2428      * argument in the direction of the second argument.  If both
2429      * arguments compare as equal the second argument is returned.
2430      *
2431      * <p>Special cases:
2432      * <ul>
2433      * <li> If either argument is a NaN, then NaN is returned.
2434      *
2435      * <li> If both arguments are signed zeros, {@code direction}
2436      * is returned unchanged (as implied by the requirement of
2437      * returning the second argument if the arguments compare as
2438      * equal).
2439      *
2440      * <li> If {@code start} is
2441      * &plusmn;{@link Double#MIN_VALUE} and {@code direction}
2442      * has a value such that the result should have a smaller
2443      * magnitude, then a zero with the same sign as {@code start}
2444      * is returned.
2445      *
2446      * <li> If {@code start} is infinite and
2447      * {@code direction} has a value such that the result should
2448      * have a smaller magnitude, {@link Double#MAX_VALUE} with the
2449      * same sign as {@code start} is returned.
2450      *
2451      * <li> If {@code start} is equal to &plusmn;
2452      * {@link Double#MAX_VALUE} and {@code direction} has a
2453      * value such that the result should have a larger magnitude, an
2454      * infinity with same sign as {@code start} is returned.
2455      * </ul>
2456      *
2457      * @param start  starting floating-point value
2458      * @param direction value indicating which of
2459      * {@code start}'s neighbors or {@code start} should
2460      * be returned
2461      * @return The floating-point number adjacent to {@code start} in the
2462      * direction of {@code direction}.
2463      * @since 1.6
2464      */
nextAfter(double start, double direction)2465     public static double nextAfter(double start, double direction) {
2466         return Math.nextAfter(start, direction);
2467     }
2468 
2469     /**
2470      * Returns the floating-point number adjacent to the first
2471      * argument in the direction of the second argument.  If both
2472      * arguments compare as equal a value equivalent to the second argument
2473      * is returned.
2474      *
2475      * <p>Special cases:
2476      * <ul>
2477      * <li> If either argument is a NaN, then NaN is returned.
2478      *
2479      * <li> If both arguments are signed zeros, a value equivalent
2480      * to {@code direction} is returned.
2481      *
2482      * <li> If {@code start} is
2483      * &plusmn;{@link Float#MIN_VALUE} and {@code direction}
2484      * has a value such that the result should have a smaller
2485      * magnitude, then a zero with the same sign as {@code start}
2486      * is returned.
2487      *
2488      * <li> If {@code start} is infinite and
2489      * {@code direction} has a value such that the result should
2490      * have a smaller magnitude, {@link Float#MAX_VALUE} with the
2491      * same sign as {@code start} is returned.
2492      *
2493      * <li> If {@code start} is equal to &plusmn;
2494      * {@link Float#MAX_VALUE} and {@code direction} has a
2495      * value such that the result should have a larger magnitude, an
2496      * infinity with same sign as {@code start} is returned.
2497      * </ul>
2498      *
2499      * @param start  starting floating-point value
2500      * @param direction value indicating which of
2501      * {@code start}'s neighbors or {@code start} should
2502      * be returned
2503      * @return The floating-point number adjacent to {@code start} in the
2504      * direction of {@code direction}.
2505      * @since 1.6
2506      */
nextAfter(float start, double direction)2507     public static float nextAfter(float start, double direction) {
2508         return Math.nextAfter(start, direction);
2509     }
2510 
2511     /**
2512      * Returns the floating-point value adjacent to {@code d} in
2513      * the direction of positive infinity.  This method is
2514      * semantically equivalent to {@code nextAfter(d,
2515      * Double.POSITIVE_INFINITY)}; however, a {@code nextUp}
2516      * implementation may run faster than its equivalent
2517      * {@code nextAfter} call.
2518      *
2519      * <p>Special Cases:
2520      * <ul>
2521      * <li> If the argument is NaN, the result is NaN.
2522      *
2523      * <li> If the argument is positive infinity, the result is
2524      * positive infinity.
2525      *
2526      * <li> If the argument is zero, the result is
2527      * {@link Double#MIN_VALUE}
2528      *
2529      * </ul>
2530      *
2531      * @param d starting floating-point value
2532      * @return The adjacent floating-point value closer to positive
2533      * infinity.
2534      * @since 1.6
2535      */
nextUp(double d)2536     public static double nextUp(double d) {
2537         return Math.nextUp(d);
2538     }
2539 
2540     /**
2541      * Returns the floating-point value adjacent to {@code f} in
2542      * the direction of positive infinity.  This method is
2543      * semantically equivalent to {@code nextAfter(f,
2544      * Float.POSITIVE_INFINITY)}; however, a {@code nextUp}
2545      * implementation may run faster than its equivalent
2546      * {@code nextAfter} call.
2547      *
2548      * <p>Special Cases:
2549      * <ul>
2550      * <li> If the argument is NaN, the result is NaN.
2551      *
2552      * <li> If the argument is positive infinity, the result is
2553      * positive infinity.
2554      *
2555      * <li> If the argument is zero, the result is
2556      * {@link Float#MIN_VALUE}
2557      *
2558      * </ul>
2559      *
2560      * @param f starting floating-point value
2561      * @return The adjacent floating-point value closer to positive
2562      * infinity.
2563      * @since 1.6
2564      */
nextUp(float f)2565     public static float nextUp(float f) {
2566         return Math.nextUp(f);
2567     }
2568 
2569     /**
2570      * Returns the floating-point value adjacent to {@code d} in
2571      * the direction of negative infinity.  This method is
2572      * semantically equivalent to {@code nextAfter(d,
2573      * Double.NEGATIVE_INFINITY)}; however, a
2574      * {@code nextDown} implementation may run faster than its
2575      * equivalent {@code nextAfter} call.
2576      *
2577      * <p>Special Cases:
2578      * <ul>
2579      * <li> If the argument is NaN, the result is NaN.
2580      *
2581      * <li> If the argument is negative infinity, the result is
2582      * negative infinity.
2583      *
2584      * <li> If the argument is zero, the result is
2585      * {@code -Double.MIN_VALUE}
2586      *
2587      * </ul>
2588      *
2589      * @param d  starting floating-point value
2590      * @return The adjacent floating-point value closer to negative
2591      * infinity.
2592      * @since 1.8
2593      */
nextDown(double d)2594     public static double nextDown(double d) {
2595         return Math.nextDown(d);
2596     }
2597 
2598     /**
2599      * Returns the floating-point value adjacent to {@code f} in
2600      * the direction of negative infinity.  This method is
2601      * semantically equivalent to {@code nextAfter(f,
2602      * Float.NEGATIVE_INFINITY)}; however, a
2603      * {@code nextDown} implementation may run faster than its
2604      * equivalent {@code nextAfter} call.
2605      *
2606      * <p>Special Cases:
2607      * <ul>
2608      * <li> If the argument is NaN, the result is NaN.
2609      *
2610      * <li> If the argument is negative infinity, the result is
2611      * negative infinity.
2612      *
2613      * <li> If the argument is zero, the result is
2614      * {@code -Float.MIN_VALUE}
2615      *
2616      * </ul>
2617      *
2618      * @param f  starting floating-point value
2619      * @return The adjacent floating-point value closer to negative
2620      * infinity.
2621      * @since 1.8
2622      */
nextDown(float f)2623     public static float nextDown(float f) {
2624         return Math.nextDown(f);
2625     }
2626 
2627     /**
2628      * Returns {@code d} &times; 2<sup>{@code scaleFactor}</sup>
2629      * rounded as if performed by a single correctly rounded
2630      * floating-point multiply.  If the exponent of the result is
2631      * between {@link Double#MIN_EXPONENT} and {@link
2632      * Double#MAX_EXPONENT}, the answer is calculated exactly.  If the
2633      * exponent of the result would be larger than {@code
2634      * Double.MAX_EXPONENT}, an infinity is returned.  Note that if
2635      * the result is subnormal, precision may be lost; that is, when
2636      * {@code scalb(x, n)} is subnormal, {@code scalb(scalb(x, n),
2637      * -n)} may not equal <i>x</i>.  When the result is non-NaN, the
2638      * result has the same sign as {@code d}.
2639      *
2640      * <p>Special cases:
2641      * <ul>
2642      * <li> If the first argument is NaN, NaN is returned.
2643      * <li> If the first argument is infinite, then an infinity of the
2644      * same sign is returned.
2645      * <li> If the first argument is zero, then a zero of the same
2646      * sign is returned.
2647      * </ul>
2648      *
2649      * @param d number to be scaled by a power of two.
2650      * @param scaleFactor power of 2 used to scale {@code d}
2651      * @return {@code d} &times; 2<sup>{@code scaleFactor}</sup>
2652      * @since 1.6
2653      */
scalb(double d, int scaleFactor)2654     public static double scalb(double d, int scaleFactor) {
2655         return Math.scalb(d, scaleFactor);
2656     }
2657 
2658     /**
2659      * Returns {@code f} &times; 2<sup>{@code scaleFactor}</sup>
2660      * rounded as if performed by a single correctly rounded
2661      * floating-point multiply.  If the exponent of the result is
2662      * between {@link Float#MIN_EXPONENT} and {@link
2663      * Float#MAX_EXPONENT}, the answer is calculated exactly.  If the
2664      * exponent of the result would be larger than {@code
2665      * Float.MAX_EXPONENT}, an infinity is returned.  Note that if the
2666      * result is subnormal, precision may be lost; that is, when
2667      * {@code scalb(x, n)} is subnormal, {@code scalb(scalb(x, n),
2668      * -n)} may not equal <i>x</i>.  When the result is non-NaN, the
2669      * result has the same sign as {@code f}.
2670      *
2671      * <p>Special cases:
2672      * <ul>
2673      * <li> If the first argument is NaN, NaN is returned.
2674      * <li> If the first argument is infinite, then an infinity of the
2675      * same sign is returned.
2676      * <li> If the first argument is zero, then a zero of the same
2677      * sign is returned.
2678      * </ul>
2679      *
2680      * @param f number to be scaled by a power of two.
2681      * @param scaleFactor power of 2 used to scale {@code f}
2682      * @return {@code f} &times; 2<sup>{@code scaleFactor}</sup>
2683      * @since 1.6
2684      */
scalb(float f, int scaleFactor)2685     public static float scalb(float f, int scaleFactor) {
2686         return Math.scalb(f, scaleFactor);
2687     }
2688 }
2689