/*
- * Copyright (c) 1994, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1994, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
 
 package java.lang;
 
 import java.lang.annotation.Native;
+import java.lang.invoke.MethodHandles;
+import java.lang.constant.Constable;
+import java.lang.constant.ConstantDesc;
 import java.math.*;
+import java.util.Objects;
+import java.util.Optional;
 
+import jdk.internal.HotSpotIntrinsicCandidate;
+import jdk.internal.misc.VM;
+
+import static java.lang.String.COMPACT_STRINGS;
+import static java.lang.String.LATIN1;
+import static java.lang.String.UTF16;
 
 /**
  * The {@code Long} class wraps a value of the primitive type {@code
  * long} in an object. An object of type {@code Long} contains a
  * single field whose type is {@code long}.
  *
  * <p> In addition, this class provides several methods for converting
  * a {@code long} to a {@code String} and a {@code String} to a {@code
  * long}, as well as other constants and methods useful when dealing
  * with a {@code long}.
  *
  * <p>Implementation note: The implementations of the "bit twiddling"
  * methods (such as {@link #highestOneBit(long) highestOneBit} and
  * {@link #numberOfTrailingZeros(long) numberOfTrailingZeros}) are
  * based on material from Henry S. Warren, Jr.'s <i>Hacker's
  * Delight</i>, (Addison Wesley, 2002).
  *
  * @author  Lee Boynton
  * @author  Arthur van Hoff
  * @author  Josh Bloch
  * @author  Joseph D. Darcy
- * @since   JDK1.0
+ * @since   1.0
  */
-public final class Long extends Number implements Comparable<Long> {
+public final class Long extends Number
+        implements Comparable<Long>, Constable, ConstantDesc {
     /**
      * A constant holding the minimum value a {@code long} can
      * have, -2<sup>63</sup>.
      */
     @Native public static final long MIN_VALUE = 0x8000000000000000L;
 
     /**
      * A constant holding the maximum value a {@code long} can
      * have, 2<sup>63</sup>-1.
      */
     @Native public static final long MAX_VALUE = 0x7fffffffffffffffL;
 
     /**
      * The {@code Class} instance representing the primitive type
      * {@code long}.
      *
-     * @since   JDK1.1
+     * @since   1.1
      */
     @SuppressWarnings("unchecked")
     public static final Class<Long>     TYPE = (Class<Long>) Class.getPrimitiveClass("long");
 
     /**
      * Returns a string representation of the first argument in the
      * radix specified by the second argument.
      *
      * <p>If the radix is smaller than {@code Character.MIN_RADIX}
      * or larger than {@code Character.MAX_RADIX}, then the radix
      * {@code 10} is used instead.
      *
      * <p>If the first argument is negative, the first element of the
      * result is the ASCII minus sign {@code '-'}
      * ({@code '\u005Cu002d'}). If the first argument is not
      * negative, no sign character appears in the result.
      *
      * <p>The remaining characters of the result represent the magnitude
      * of the first argument. If the magnitude is zero, it is
      * represented by a single zero character {@code '0'}
      * ({@code '\u005Cu0030'}); otherwise, the first character of
      * the representation of the magnitude will not be the zero
      * character.  The following ASCII characters are used as digits:
      *
      * <blockquote>
      *   {@code 0123456789abcdefghijklmnopqrstuvwxyz}
      * </blockquote>
      *
      * These are {@code '\u005Cu0030'} through
      * {@code '\u005Cu0039'} and {@code '\u005Cu0061'} through
      * {@code '\u005Cu007a'}. If {@code radix} is
      * <var>N</var>, then the first <var>N</var> of these characters
      * are used as radix-<var>N</var> digits in the order shown. Thus,
      * the digits for hexadecimal (radix 16) are
      * {@code 0123456789abcdef}. If uppercase letters are
      * desired, the {@link java.lang.String#toUpperCase()} method may
      * be called on the result:
      *
      * <blockquote>
      *  {@code Long.toString(n, 16).toUpperCase()}
      * </blockquote>
      *
      * @param   i       a {@code long} to be converted to a string.
      * @param   radix   the radix to use in the string representation.
      * @return  a string representation of the argument in the specified radix.
      * @see     java.lang.Character#MAX_RADIX
      * @see     java.lang.Character#MIN_RADIX
      */
     public static String toString(long i, int radix) {
         if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX)
             radix = 10;
         if (radix == 10)
             return toString(i);
-        char[] buf = new char[65];
+
+        if (COMPACT_STRINGS) {
+            byte[] buf = new byte[65];
+            int charPos = 64;
+            boolean negative = (i < 0);
+
+            if (!negative) {
+                i = -i;
+            }
+
+            while (i <= -radix) {
+                buf[charPos--] = (byte)Integer.digits[(int)(-(i % radix))];
+                i = i / radix;
+            }
+            buf[charPos] = (byte)Integer.digits[(int)(-i)];
+
+            if (negative) {
+                buf[--charPos] = '-';
+            }
+            return StringLatin1.newString(buf, charPos, (65 - charPos));
+        }
+        return toStringUTF16(i, radix);
+    }
+
+    private static String toStringUTF16(long i, int radix) {
+        byte[] buf = new byte[65 * 2];
         int charPos = 64;
         boolean negative = (i < 0);
-
         if (!negative) {
             i = -i;
         }
-
         while (i <= -radix) {
-            buf[charPos--] = Integer.digits[(int)(-(i % radix))];
+            StringUTF16.putChar(buf, charPos--, Integer.digits[(int)(-(i % radix))]);
             i = i / radix;
         }
-        buf[charPos] = Integer.digits[(int)(-i)];
-
+        StringUTF16.putChar(buf, charPos, Integer.digits[(int)(-i)]);
         if (negative) {
-            buf[--charPos] = '-';
+            StringUTF16.putChar(buf, --charPos, '-');
         }
-
-        return new String(buf, charPos, (65 - charPos));
+        return StringUTF16.newString(buf, charPos, (65 - charPos));
     }
 
     /**
      * Returns a string representation of the first argument as an
      * unsigned integer value in the radix specified by the second
      * argument.
      *
      * <p>If the radix is smaller than {@code Character.MIN_RADIX}
      * or larger than {@code Character.MAX_RADIX}, then the radix
      * {@code 10} is used instead.
      *
      * <p>Note that since the first argument is treated as an unsigned
      * value, no leading sign character is printed.
      *
      * <p>If the magnitude is zero, it is represented by a single zero
      * character {@code '0'} ({@code '\u005Cu0030'}); otherwise,
      * the first character of the representation of the magnitude will
      * not be the zero character.
      *
      * <p>The behavior of radixes and the characters used as digits
      * are the same as {@link #toString(long, int) toString}.
      *
      * @param   i       an integer to be converted to an unsigned string.
      * @param   radix   the radix to use in the string representation.
      * @return  an unsigned string representation of the argument in the specified radix.
      * @see     #toString(long, int)
      * @since 1.8
      */
     public static String toUnsignedString(long i, int radix) {
         if (i >= 0)
             return toString(i, radix);
         else {
             switch (radix) {
             case 2:
                 return toBinaryString(i);
 
             case 4:
                 return toUnsignedString0(i, 2);
 
             case 8:
                 return toOctalString(i);
 
             case 10:
                 /*
                  * We can get the effect of an unsigned division by 10
                  * on a long value by first shifting right, yielding a
                  * positive value, and then dividing by 5.  This
                  * allows the last digit and preceding digits to be
                  * isolated more quickly than by an initial conversion
                  * to BigInteger.
                  */
                 long quot = (i >>> 1) / 5;
                 long rem = i - quot * 10;
                 return toString(quot) + rem;
 
             case 16:
                 return toHexString(i);
 
             case 32:
                 return toUnsignedString0(i, 5);
 
             default:
                 return toUnsignedBigInteger(i).toString(radix);
             }
         }
     }
 
     /**
      * Return a BigInteger equal to the unsigned value of the
      * argument.
      */
     private static BigInteger toUnsignedBigInteger(long i) {
         if (i >= 0L)
             return BigInteger.valueOf(i);
         else {
             int upper = (int) (i >>> 32);
             int lower = (int) i;
 
             // return (upper << 32) + lower
             return (BigInteger.valueOf(Integer.toUnsignedLong(upper))).shiftLeft(32).
                 add(BigInteger.valueOf(Integer.toUnsignedLong(lower)));
         }
     }
 
     /**
      * Returns a string representation of the {@code long}
      * argument as an unsigned integer in base&nbsp;16.
      *
      * <p>The unsigned {@code long} value is the argument plus
      * 2<sup>64</sup> if the argument is negative; otherwise, it is
      * equal to the argument.  This value is converted to a string of
      * ASCII digits in hexadecimal (base&nbsp;16) with no extra
      * leading {@code 0}s.
      *
      * <p>The value of the argument can be recovered from the returned
      * string {@code s} by calling {@link
      * Long#parseUnsignedLong(String, int) Long.parseUnsignedLong(s,
      * 16)}.
      *
      * <p>If the unsigned magnitude is zero, it is represented by a
      * single zero character {@code '0'} ({@code '\u005Cu0030'});
      * otherwise, the first character of the representation of the
      * unsigned magnitude will not be the zero character. The
      * following characters are used as hexadecimal digits:
      *
      * <blockquote>
      *  {@code 0123456789abcdef}
      * </blockquote>
      *
      * These are the characters {@code '\u005Cu0030'} through
      * {@code '\u005Cu0039'} and  {@code '\u005Cu0061'} through
      * {@code '\u005Cu0066'}.  If uppercase letters are desired,
      * the {@link java.lang.String#toUpperCase()} method may be called
      * on the result:
      *
      * <blockquote>
      *  {@code Long.toHexString(n).toUpperCase()}
      * </blockquote>
      *
      * @param   i   a {@code long} to be converted to a string.
      * @return  the string representation of the unsigned {@code long}
      *          value represented by the argument in hexadecimal
      *          (base&nbsp;16).
      * @see #parseUnsignedLong(String, int)
      * @see #toUnsignedString(long, int)
-     * @since   JDK 1.0.2
+     * @since   1.0.2
      */
     public static String toHexString(long i) {
         return toUnsignedString0(i, 4);
     }
 
     /**
      * Returns a string representation of the {@code long}
      * argument as an unsigned integer in base&nbsp;8.
      *
      * <p>The unsigned {@code long} value is the argument plus
      * 2<sup>64</sup> if the argument is negative; otherwise, it is
      * equal to the argument.  This value is converted to a string of
      * ASCII digits in octal (base&nbsp;8) with no extra leading
      * {@code 0}s.
      *
      * <p>The value of the argument can be recovered from the returned
      * string {@code s} by calling {@link
      * Long#parseUnsignedLong(String, int) Long.parseUnsignedLong(s,
      * 8)}.
      *
      * <p>If the unsigned magnitude is zero, it is represented by a
      * single zero character {@code '0'} ({@code '\u005Cu0030'});
      * otherwise, the first character of the representation of the
      * unsigned magnitude will not be the zero character. The
      * following characters are used as octal digits:
      *
      * <blockquote>
      *  {@code 01234567}
      * </blockquote>
      *
      * These are the characters {@code '\u005Cu0030'} through
      * {@code '\u005Cu0037'}.
      *
      * @param   i   a {@code long} to be converted to a string.
      * @return  the string representation of the unsigned {@code long}
      *          value represented by the argument in octal (base&nbsp;8).
      * @see #parseUnsignedLong(String, int)
      * @see #toUnsignedString(long, int)
-     * @since   JDK 1.0.2
+     * @since   1.0.2
      */
     public static String toOctalString(long i) {
         return toUnsignedString0(i, 3);
     }
 
     /**
      * Returns a string representation of the {@code long}
      * argument as an unsigned integer in base&nbsp;2.
      *
      * <p>The unsigned {@code long} value is the argument plus
      * 2<sup>64</sup> if the argument is negative; otherwise, it is
      * equal to the argument.  This value is converted to a string of
      * ASCII digits in binary (base&nbsp;2) with no extra leading
      * {@code 0}s.
      *
      * <p>The value of the argument can be recovered from the returned
      * string {@code s} by calling {@link
      * Long#parseUnsignedLong(String, int) Long.parseUnsignedLong(s,
      * 2)}.
      *
      * <p>If the unsigned magnitude is zero, it is represented by a
      * single zero character {@code '0'} ({@code '\u005Cu0030'});
      * otherwise, the first character of the representation of the
      * unsigned magnitude will not be the zero character. The
      * characters {@code '0'} ({@code '\u005Cu0030'}) and {@code
      * '1'} ({@code '\u005Cu0031'}) are used as binary digits.
      *
      * @param   i   a {@code long} to be converted to a string.
      * @return  the string representation of the unsigned {@code long}
      *          value represented by the argument in binary (base&nbsp;2).
      * @see #parseUnsignedLong(String, int)
      * @see #toUnsignedString(long, int)
-     * @since   JDK 1.0.2
+     * @since   1.0.2
      */
     public static String toBinaryString(long i) {
         return toUnsignedString0(i, 1);
     }
 
     /**
      * Format a long (treated as unsigned) into a String.
      * @param val the value to format
      * @param shift the log2 of the base to format in (4 for hex, 3 for octal, 1 for binary)
      */
     static String toUnsignedString0(long val, int shift) {
         // assert shift > 0 && shift <=5 : "Illegal shift value";
         int mag = Long.SIZE - Long.numberOfLeadingZeros(val);
         int chars = Math.max(((mag + (shift - 1)) / shift), 1);
-        char[] buf = new char[chars];
-
-        formatUnsignedLong(val, shift, buf, 0, chars);
-        return new String(buf, true);
+        if (COMPACT_STRINGS) {
+            byte[] buf = new byte[chars];
+            formatUnsignedLong0(val, shift, buf, 0, chars);
+            return new String(buf, LATIN1);
+        } else {
+            byte[] buf = new byte[chars * 2];
+            formatUnsignedLong0UTF16(val, shift, buf, 0, chars);
+            return new String(buf, UTF16);
+        }
     }
 
     /**
-     * Format a long (treated as unsigned) into a character buffer.
+     * Format a long (treated as unsigned) into a character buffer. If
+     * {@code len} exceeds the formatted ASCII representation of {@code val},
+     * {@code buf} will be padded with leading zeroes.
+     *
      * @param val the unsigned long to format
      * @param shift the log2 of the base to format in (4 for hex, 3 for octal, 1 for binary)
      * @param buf the character buffer to write to
      * @param offset the offset in the destination buffer to start at
      * @param len the number of characters to write
-     * @return the lowest character location used
      */
-     static int formatUnsignedLong(long val, int shift, char[] buf, int offset, int len) {
-        int charPos = len;
+
+    /** byte[]/LATIN1 version    */
+    static void formatUnsignedLong0(long val, int shift, byte[] buf, int offset, int len) {
+        int charPos = offset + len;
         int radix = 1 << shift;
         int mask = radix - 1;
         do {
-            buf[offset + --charPos] = Integer.digits[((int) val) & mask];
+            buf[--charPos] = (byte)Integer.digits[((int) val) & mask];
             val >>>= shift;
-        } while (val != 0 && charPos > 0);
+        } while (charPos > offset);
+    }
 
-        return charPos;
+    /** byte[]/UTF16 version    */
+    private static void formatUnsignedLong0UTF16(long val, int shift, byte[] buf, int offset, int len) {
+        int charPos = offset + len;
+        int radix = 1 << shift;
+        int mask = radix - 1;
+        do {
+            StringUTF16.putChar(buf, --charPos, Integer.digits[((int) val) & mask]);
+            val >>>= shift;
+        } while (charPos > offset);
+    }
+
+    static String fastUUID(long lsb, long msb) {
+        if (COMPACT_STRINGS) {
+            byte[] buf = new byte[36];
+            formatUnsignedLong0(lsb,        4, buf, 24, 12);
+            formatUnsignedLong0(lsb >>> 48, 4, buf, 19, 4);
+            formatUnsignedLong0(msb,        4, buf, 14, 4);
+            formatUnsignedLong0(msb >>> 16, 4, buf, 9,  4);
+            formatUnsignedLong0(msb >>> 32, 4, buf, 0,  8);
+
+            buf[23] = '-';
+            buf[18] = '-';
+            buf[13] = '-';
+            buf[8]  = '-';
+
+            return new String(buf, LATIN1);
+        } else {
+            byte[] buf = new byte[72];
+
+            formatUnsignedLong0UTF16(lsb,        4, buf, 24, 12);
+            formatUnsignedLong0UTF16(lsb >>> 48, 4, buf, 19, 4);
+            formatUnsignedLong0UTF16(msb,        4, buf, 14, 4);
+            formatUnsignedLong0UTF16(msb >>> 16, 4, buf, 9,  4);
+            formatUnsignedLong0UTF16(msb >>> 32, 4, buf, 0,  8);
+
+            StringUTF16.putChar(buf, 23, '-');
+            StringUTF16.putChar(buf, 18, '-');
+            StringUTF16.putChar(buf, 13, '-');
+            StringUTF16.putChar(buf,  8, '-');
+
+            return new String(buf, UTF16);
+        }
     }
 
     /**
      * Returns a {@code String} object representing the specified
      * {@code long}.  The argument is converted to signed decimal
      * representation and returned as a string, exactly as if the
      * argument and the radix 10 were given as arguments to the {@link
      * #toString(long, int)} method.
      *
      * @param   i   a {@code long} to be converted.
      * @return  a string representation of the argument in base&nbsp;10.
      */
     public static String toString(long i) {
-        if (i == Long.MIN_VALUE)
-            return "-9223372036854775808";
-        int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i);
-        char[] buf = new char[size];
-        getChars(i, size, buf);
-        return new String(buf, true);
+        int size = stringSize(i);
+        if (COMPACT_STRINGS) {
+            byte[] buf = new byte[size];
+            getChars(i, size, buf);
+            return new String(buf, LATIN1);
+        } else {
+            byte[] buf = new byte[size * 2];
+            StringUTF16.getChars(i, size, buf);
+            return new String(buf, UTF16);
+        }
     }
 
     /**
      * Returns a string representation of the argument as an unsigned
      * decimal value.
      *
      * The argument is converted to unsigned decimal representation
      * and returned as a string exactly as if the argument and radix
      * 10 were given as arguments to the {@link #toUnsignedString(long,
      * int)} method.
      *
      * @param   i  an integer to be converted to an unsigned string.
      * @return  an unsigned string representation of the argument.
      * @see     #toUnsignedString(long, int)
      * @since 1.8
      */
     public static String toUnsignedString(long i) {
         return toUnsignedString(i, 10);
     }
 
     /**
-     * Places characters representing the integer i into the
+     * Places characters representing the long i into the
      * character array buf. The characters are placed into
      * the buffer backwards starting with the least significant
      * digit at the specified index (exclusive), and working
      * backwards from there.
      *
-     * Will fail if i == Long.MIN_VALUE
+     * @implNote This method converts positive inputs into negative
+     * values, to cover the Long.MIN_VALUE case. Converting otherwise
+     * (negative to positive) will expose -Long.MIN_VALUE that overflows
+     * long.
+     *
+     * @param i     value to convert
+     * @param index next index, after the least significant digit
+     * @param buf   target buffer, Latin1-encoded
+     * @return index of the most significant digit or minus sign, if present
      */
-    static void getChars(long i, int index, char[] buf) {
+    static int getChars(long i, int index, byte[] buf) {
         long q;
         int r;
         int charPos = index;
-        char sign = 0;
 
-        if (i < 0) {
-            sign = '-';
+        boolean negative = (i < 0);
+        if (!negative) {
             i = -i;
         }
 
         // Get 2 digits/iteration using longs until quotient fits into an int
-        while (i > Integer.MAX_VALUE) {
+        while (i <= Integer.MIN_VALUE) {
             q = i / 100;
-            // really: r = i - (q * 100);
-            r = (int)(i - ((q << 6) + (q << 5) + (q << 2)));
+            r = (int)((q * 100) - i);
             i = q;
             buf[--charPos] = Integer.DigitOnes[r];
             buf[--charPos] = Integer.DigitTens[r];
         }
 
         // Get 2 digits/iteration using ints
         int q2;
         int i2 = (int)i;
-        while (i2 >= 65536) {
+        while (i2 <= -100) {
             q2 = i2 / 100;
-            // really: r = i2 - (q * 100);
-            r = i2 - ((q2 << 6) + (q2 << 5) + (q2 << 2));
+            r  = (q2 * 100) - i2;
             i2 = q2;
             buf[--charPos] = Integer.DigitOnes[r];
             buf[--charPos] = Integer.DigitTens[r];
         }
 
-        // Fall thru to fast mode for smaller numbers
-        // assert(i2 <= 65536, i2);
-        for (;;) {
-            q2 = (i2 * 52429) >>> (16+3);
-            r = i2 - ((q2 << 3) + (q2 << 1));  // r = i2-(q2*10) ...
-            buf[--charPos] = Integer.digits[r];
-            i2 = q2;
-            if (i2 == 0) break;
+        // We know there are at most two digits left at this point.
+        q2 = i2 / 10;
+        r  = (q2 * 10) - i2;
+        buf[--charPos] = (byte)('0' + r);
+
+        // Whatever left is the remaining digit.
+        if (q2 < 0) {
+            buf[--charPos] = (byte)('0' - q2);
         }
-        if (sign != 0) {
-            buf[--charPos] = sign;
+
+        if (negative) {
+            buf[--charPos] = (byte)'-';
         }
+        return charPos;
     }
 
-    // Requires positive x
+    /**
+     * Returns the string representation size for a given long value.
+     *
+     * @param x long value
+     * @return string size
+     *
+     * @implNote There are other ways to compute this: e.g. binary search,
+     * but values are biased heavily towards zero, and therefore linear search
+     * wins. The iteration results are also routinely inlined in the generated
+     * code after loop unrolling.
+     */
     static int stringSize(long x) {
-        long p = 10;
-        for (int i=1; i<19; i++) {
-            if (x < p)
-                return i;
-            p = 10*p;
+        int d = 1;
+        if (x >= 0) {
+            d = 0;
+            x = -x;
         }
-        return 19;
+        long p = -10;
+        for (int i = 1; i < 19; i++) {
+            if (x > p)
+                return i + d;
+            p = 10 * p;
+        }
+        return 19 + d;
     }
 
     /**
      * Parses the string argument as a signed {@code long} in the
      * radix specified by the second argument. The characters in the
      * string must all be digits of the specified radix (as determined
      * by whether {@link java.lang.Character#digit(char, int)} returns
      * a nonnegative value), except that the first character may be an
      * ASCII minus sign {@code '-'} ({@code '\u005Cu002D'}) to
      * indicate a negative value or an ASCII plus sign {@code '+'}
      * ({@code '\u005Cu002B'}) to indicate a positive value. The
      * resulting {@code long} value is returned.
      *
      * <p>Note that neither the character {@code L}
      * ({@code '\u005Cu004C'}) nor {@code l}
      * ({@code '\u005Cu006C'}) is permitted to appear at the end
      * of the string as a type indicator, as would be permitted in
      * Java programming language source code - except that either
      * {@code L} or {@code l} may appear as a digit for a
      * radix greater than or equal to 22.
      *
      * <p>An exception of type {@code NumberFormatException} is
      * thrown if any of the following situations occurs:
      * <ul>
      *
      * <li>The first argument is {@code null} or is a string of
      * length zero.
      *
      * <li>The {@code radix} is either smaller than {@link
      * java.lang.Character#MIN_RADIX} or larger than {@link
      * java.lang.Character#MAX_RADIX}.
      *
      * <li>Any character of the string is not a digit of the specified
      * radix, except that the first character may be a minus sign
      * {@code '-'} ({@code '\u005Cu002d'}) or plus sign {@code
      * '+'} ({@code '\u005Cu002B'}) provided that the string is
      * longer than length 1.
      *
      * <li>The value represented by the string is not a value of type
      *      {@code long}.
      * </ul>
      *
      * <p>Examples:
      * <blockquote><pre>
      * parseLong("0", 10) returns 0L
      * parseLong("473", 10) returns 473L
      * parseLong("+42", 10) returns 42L
      * parseLong("-0", 10) returns 0L
      * parseLong("-FF", 16) returns -255L
      * parseLong("1100110", 2) returns 102L
      * parseLong("99", 8) throws a NumberFormatException
      * parseLong("Hazelnut", 10) throws a NumberFormatException
      * parseLong("Hazelnut", 36) returns 1356099454469L
      * </pre></blockquote>
      *
      * @param      s       the {@code String} containing the
      *                     {@code long} representation to be parsed.
      * @param      radix   the radix to be used while parsing {@code s}.
      * @return     the {@code long} represented by the string argument in
      *             the specified radix.
      * @throws     NumberFormatException  if the string does not contain a
      *             parsable {@code long}.
      */
     public static long parseLong(String s, int radix)
               throws NumberFormatException
     {
         if (s == null) {
             throw new NumberFormatException("null");
         }
 
         if (radix < Character.MIN_RADIX) {
             throw new NumberFormatException("radix " + radix +
                                             " less than Character.MIN_RADIX");
         }
         if (radix > Character.MAX_RADIX) {
             throw new NumberFormatException("radix " + radix +
                                             " greater than Character.MAX_RADIX");
         }
 
-        long result = 0;
         boolean negative = false;
         int i = 0, len = s.length();
         long limit = -Long.MAX_VALUE;
-        long multmin;
-        int digit;
 
         if (len > 0) {
             char firstChar = s.charAt(0);
             if (firstChar < '0') { // Possible leading "+" or "-"
                 if (firstChar == '-') {
                     negative = true;
                     limit = Long.MIN_VALUE;
-                } else if (firstChar != '+')
-                    throw NumberFormatException.forInputString(s);
+                } else if (firstChar != '+') {
+                    throw NumberFormatException.forInputString(s, radix);
+                }
 
-                if (len == 1) // Cannot have lone "+" or "-"
-                    throw NumberFormatException.forInputString(s);
+                if (len == 1) { // Cannot have lone "+" or "-"
+                    throw NumberFormatException.forInputString(s, radix);
+                }
                 i++;
             }
-            multmin = limit / radix;
+            long multmin = limit / radix;
+            long result = 0;
             while (i < len) {
                 // Accumulating negatively avoids surprises near MAX_VALUE
-                digit = Character.digit(s.charAt(i++),radix);
-                if (digit < 0) {
-                    throw NumberFormatException.forInputString(s);
-                }
-                if (result < multmin) {
-                    throw NumberFormatException.forInputString(s);
+                int digit = Character.digit(s.charAt(i++),radix);
+                if (digit < 0 || result < multmin) {
+                    throw NumberFormatException.forInputString(s, radix);
                 }
                 result *= radix;
                 if (result < limit + digit) {
-                    throw NumberFormatException.forInputString(s);
+                    throw NumberFormatException.forInputString(s, radix);
                 }
                 result -= digit;
             }
+            return negative ? result : -result;
         } else {
-            throw NumberFormatException.forInputString(s);
+            throw NumberFormatException.forInputString(s, radix);
         }
-        return negative ? result : -result;
+    }
+
+    /**
+     * Parses the {@link CharSequence} argument as a signed {@code long} in
+     * the specified {@code radix}, beginning at the specified
+     * {@code beginIndex} and extending to {@code endIndex - 1}.
+     *
+     * <p>The method does not take steps to guard against the
+     * {@code CharSequence} being mutated while parsing.
+     *
+     * @param      s   the {@code CharSequence} containing the {@code long}
+     *                  representation to be parsed
+     * @param      beginIndex   the beginning index, inclusive.
+     * @param      endIndex     the ending index, exclusive.
+     * @param      radix   the radix to be used while parsing {@code s}.
+     * @return     the signed {@code long} represented by the subsequence in
+     *             the specified radix.
+     * @throws     NullPointerException  if {@code s} is null.
+     * @throws     IndexOutOfBoundsException  if {@code beginIndex} is
+     *             negative, or if {@code beginIndex} is greater than
+     *             {@code endIndex} or if {@code endIndex} is greater than
+     *             {@code s.length()}.
+     * @throws     NumberFormatException  if the {@code CharSequence} does not
+     *             contain a parsable {@code int} in the specified
+     *             {@code radix}, or if {@code radix} is either smaller than
+     *             {@link java.lang.Character#MIN_RADIX} or larger than
+     *             {@link java.lang.Character#MAX_RADIX}.
+     * @since  9
+     */
+    public static long parseLong(CharSequence s, int beginIndex, int endIndex, int radix)
+                throws NumberFormatException {
+        s = Objects.requireNonNull(s);
+
+        if (beginIndex < 0 || beginIndex > endIndex || endIndex > s.length()) {
+            throw new IndexOutOfBoundsException();
+        }
+        if (radix < Character.MIN_RADIX) {
+            throw new NumberFormatException("radix " + radix +
+                    " less than Character.MIN_RADIX");
+        }
+        if (radix > Character.MAX_RADIX) {
+            throw new NumberFormatException("radix " + radix +
+                    " greater than Character.MAX_RADIX");
+        }
+
+        boolean negative = false;
+        int i = beginIndex;
+        long limit = -Long.MAX_VALUE;
+
+        if (i < endIndex) {
+            char firstChar = s.charAt(i);
+            if (firstChar < '0') { // Possible leading "+" or "-"
+                if (firstChar == '-') {
+                    negative = true;
+                    limit = Long.MIN_VALUE;
+                } else if (firstChar != '+') {
+                    throw NumberFormatException.forCharSequence(s, beginIndex,
+                            endIndex, i);
+                }
+                i++;
+            }
+            if (i >= endIndex) { // Cannot have lone "+", "-" or ""
+                throw NumberFormatException.forCharSequence(s, beginIndex,
+                        endIndex, i);
+            }
+            long multmin = limit / radix;
+            long result = 0;
+            while (i < endIndex) {
+                // Accumulating negatively avoids surprises near MAX_VALUE
+                int digit = Character.digit(s.charAt(i), radix);
+                if (digit < 0 || result < multmin) {
+                    throw NumberFormatException.forCharSequence(s, beginIndex,
+                            endIndex, i);
+                }
+                result *= radix;
+                if (result < limit + digit) {
+                    throw NumberFormatException.forCharSequence(s, beginIndex,
+                            endIndex, i);
+                }
+                i++;
+                result -= digit;
+            }
+            return negative ? result : -result;
+        } else {
+            throw new NumberFormatException("");
+        }
     }
 
     /**
      * Parses the string argument as a signed decimal {@code long}.
      * The characters in the string must all be decimal digits, except
      * that the first character may be an ASCII minus sign {@code '-'}
      * ({@code \u005Cu002D'}) to indicate a negative value or an
      * ASCII plus sign {@code '+'} ({@code '\u005Cu002B'}) to
      * indicate a positive value. The resulting {@code long} value is
      * returned, exactly as if the argument and the radix {@code 10}
      * were given as arguments to the {@link
      * #parseLong(java.lang.String, int)} method.
      *
      * <p>Note that neither the character {@code L}
      * ({@code '\u005Cu004C'}) nor {@code l}
      * ({@code '\u005Cu006C'}) is permitted to appear at the end
      * of the string as a type indicator, as would be permitted in
      * Java programming language source code.
      *
      * @param      s   a {@code String} containing the {@code long}
      *             representation to be parsed
      * @return     the {@code long} represented by the argument in
      *             decimal.
      * @throws     NumberFormatException  if the string does not contain a
      *             parsable {@code long}.
      */
     public static long parseLong(String s) throws NumberFormatException {
         return parseLong(s, 10);
     }
 
     /**
      * Parses the string argument as an unsigned {@code long} in the
      * radix specified by the second argument.  An unsigned integer
      * maps the values usually associated with negative numbers to
      * positive numbers larger than {@code MAX_VALUE}.
      *
      * The characters in the string must all be digits of the
      * specified radix (as determined by whether {@link
      * java.lang.Character#digit(char, int)} returns a nonnegative
      * value), except that the first character may be an ASCII plus
      * sign {@code '+'} ({@code '\u005Cu002B'}). The resulting
      * integer value is returned.
      *
      * <p>An exception of type {@code NumberFormatException} is
      * thrown if any of the following situations occurs:
      * <ul>
      * <li>The first argument is {@code null} or is a string of
      * length zero.
      *
      * <li>The radix is either smaller than
      * {@link java.lang.Character#MIN_RADIX} or
      * larger than {@link java.lang.Character#MAX_RADIX}.
      *
      * <li>Any character of the string is not a digit of the specified
      * radix, except that the first character may be a plus sign
      * {@code '+'} ({@code '\u005Cu002B'}) provided that the
      * string is longer than length 1.
      *
      * <li>The value represented by the string is larger than the
      * largest unsigned {@code long}, 2<sup>64</sup>-1.
      *
      * </ul>
      *
      *
      * @param      s   the {@code String} containing the unsigned integer
      *                  representation to be parsed
      * @param      radix   the radix to be used while parsing {@code s}.
      * @return     the unsigned {@code long} represented by the string
      *             argument in the specified radix.
      * @throws     NumberFormatException if the {@code String}
      *             does not contain a parsable {@code long}.
      * @since 1.8
      */
     public static long parseUnsignedLong(String s, int radix)
                 throws NumberFormatException {
         if (s == null)  {
             throw new NumberFormatException("null");
         }
 
         int len = s.length();
         if (len > 0) {
             char firstChar = s.charAt(0);
             if (firstChar == '-') {
                 throw new
                     NumberFormatException(String.format("Illegal leading minus sign " +
                                                        "on unsigned string %s.", s));
             } else {
                 if (len <= 12 || // Long.MAX_VALUE in Character.MAX_RADIX is 13 digits
                     (radix == 10 && len <= 18) ) { // Long.MAX_VALUE in base 10 is 19 digits
                     return parseLong(s, radix);
                 }
 
                 // No need for range checks on len due to testing above.
-                long first = parseLong(s.substring(0, len - 1), radix);
+                long first = parseLong(s, 0, len - 1, radix);
                 int second = Character.digit(s.charAt(len - 1), radix);
                 if (second < 0) {
                     throw new NumberFormatException("Bad digit at end of " + s);
                 }
                 long result = first * radix + second;
-                if (compareUnsigned(result, first) < 0) {
+
+                /*
+                 * Test leftmost bits of multiprecision extension of first*radix
+                 * for overflow. The number of bits needed is defined by
+                 * GUARD_BIT = ceil(log2(Character.MAX_RADIX)) + 1 = 7. Then
+                 * int guard = radix*(int)(first >>> (64 - GUARD_BIT)) and
+                 * overflow is tested by splitting guard in the ranges
+                 * guard < 92, 92 <= guard < 128, and 128 <= guard, where
+                 * 92 = 128 - Character.MAX_RADIX. Note that guard cannot take
+                 * on a value which does not include a prime factor in the legal
+                 * radix range.
+                 */
+                int guard = radix * (int) (first >>> 57);
+                if (guard >= 128 ||
+                    (result >= 0 && guard >= 128 - Character.MAX_RADIX)) {
                     /*
-                     * The maximum unsigned value, (2^64)-1, takes at
-                     * most one more digit to represent than the
-                     * maximum signed value, (2^63)-1.  Therefore,
-                     * parsing (len - 1) digits will be appropriately
-                     * in-range of the signed parsing.  In other
-                     * words, if parsing (len -1) digits overflows
-                     * signed parsing, parsing len digits will
-                     * certainly overflow unsigned parsing.
+                     * For purposes of exposition, the programmatic statements
+                     * below should be taken to be multi-precision, i.e., not
+                     * subject to overflow.
                      *
-                     * The compareUnsigned check above catches
-                     * situations where an unsigned overflow occurs
-                     * incorporating the contribution of the final
-                     * digit.
+                     * A) Condition guard >= 128:
+                     * If guard >= 128 then first*radix >= 2^7 * 2^57 = 2^64
+                     * hence always overflow.
+                     *
+                     * B) Condition guard < 92:
+                     * Define left7 = first >>> 57.
+                     * Given first = (left7 * 2^57) + (first & (2^57 - 1)) then
+                     * result <= (radix*left7)*2^57 + radix*(2^57 - 1) + second.
+                     * Thus if radix*left7 < 92, radix <= 36, and second < 36,
+                     * then result < 92*2^57 + 36*(2^57 - 1) + 36 = 2^64 hence
+                     * never overflow.
+                     *
+                     * C) Condition 92 <= guard < 128:
+                     * first*radix + second >= radix*left7*2^57 + second
+                     * so that first*radix + second >= 92*2^57 + 0 > 2^63
+                     *
+                     * D) Condition guard < 128:
+                     * radix*first <= (radix*left7) * 2^57 + radix*(2^57 - 1)
+                     * so
+                     * radix*first + second <= (radix*left7) * 2^57 + radix*(2^57 - 1) + 36
+                     * thus
+                     * radix*first + second < 128 * 2^57 + 36*2^57 - radix + 36
+                     * whence
+                     * radix*first + second < 2^64 + 2^6*2^57 = 2^64 + 2^63
+                     *
+                     * E) Conditions C, D, and result >= 0:
+                     * C and D combined imply the mathematical result
+                     * 2^63 < first*radix + second < 2^64 + 2^63. The lower
+                     * bound is therefore negative as a signed long, but the
+                     * upper bound is too small to overflow again after the
+                     * signed long overflows to positive above 2^64 - 1. Hence
+                     * result >= 0 implies overflow given C and D.
                      */
                     throw new NumberFormatException(String.format("String value %s exceeds " +
                                                                   "range of unsigned long.", s));
                 }
                 return result;
             }
         } else {
-            throw NumberFormatException.forInputString(s);
+            throw NumberFormatException.forInputString(s, radix);
+        }
+    }
+
+    /**
+     * Parses the {@link CharSequence} argument as an unsigned {@code long} in
+     * the specified {@code radix}, beginning at the specified
+     * {@code beginIndex} and extending to {@code endIndex - 1}.
+     *
+     * <p>The method does not take steps to guard against the
+     * {@code CharSequence} being mutated while parsing.
+     *
+     * @param      s   the {@code CharSequence} containing the unsigned
+     *                 {@code long} representation to be parsed
+     * @param      beginIndex   the beginning index, inclusive.
+     * @param      endIndex     the ending index, exclusive.
+     * @param      radix   the radix to be used while parsing {@code s}.
+     * @return     the unsigned {@code long} represented by the subsequence in
+     *             the specified radix.
+     * @throws     NullPointerException  if {@code s} is null.
+     * @throws     IndexOutOfBoundsException  if {@code beginIndex} is
+     *             negative, or if {@code beginIndex} is greater than
+     *             {@code endIndex} or if {@code endIndex} is greater than
+     *             {@code s.length()}.
+     * @throws     NumberFormatException  if the {@code CharSequence} does not
+     *             contain a parsable unsigned {@code long} in the specified
+     *             {@code radix}, or if {@code radix} is either smaller than
+     *             {@link java.lang.Character#MIN_RADIX} or larger than
+     *             {@link java.lang.Character#MAX_RADIX}.
+     * @since  9
+     */
+    public static long parseUnsignedLong(CharSequence s, int beginIndex, int endIndex, int radix)
+                throws NumberFormatException {
+        s = Objects.requireNonNull(s);
+
+        if (beginIndex < 0 || beginIndex > endIndex || endIndex > s.length()) {
+            throw new IndexOutOfBoundsException();
+        }
+        int start = beginIndex, len = endIndex - beginIndex;
+
+        if (len > 0) {
+            char firstChar = s.charAt(start);
+            if (firstChar == '-') {
+                throw new NumberFormatException(String.format("Illegal leading minus sign " +
+                        "on unsigned string %s.", s.subSequence(start, start + len)));
+            } else {
+                if (len <= 12 || // Long.MAX_VALUE in Character.MAX_RADIX is 13 digits
+                    (radix == 10 && len <= 18) ) { // Long.MAX_VALUE in base 10 is 19 digits
+                    return parseLong(s, start, start + len, radix);
+                }
+
+                // No need for range checks on end due to testing above.
+                long first = parseLong(s, start, start + len - 1, radix);
+                int second = Character.digit(s.charAt(start + len - 1), radix);
+                if (second < 0) {
+                    throw new NumberFormatException("Bad digit at end of " +
+                            s.subSequence(start, start + len));
+                }
+                long result = first * radix + second;
+
+                /*
+                 * Test leftmost bits of multiprecision extension of first*radix
+                 * for overflow. The number of bits needed is defined by
+                 * GUARD_BIT = ceil(log2(Character.MAX_RADIX)) + 1 = 7. Then
+                 * int guard = radix*(int)(first >>> (64 - GUARD_BIT)) and
+                 * overflow is tested by splitting guard in the ranges
+                 * guard < 92, 92 <= guard < 128, and 128 <= guard, where
+                 * 92 = 128 - Character.MAX_RADIX. Note that guard cannot take
+                 * on a value which does not include a prime factor in the legal
+                 * radix range.
+                 */
+                int guard = radix * (int) (first >>> 57);
+                if (guard >= 128 ||
+                        (result >= 0 && guard >= 128 - Character.MAX_RADIX)) {
+                    /*
+                     * For purposes of exposition, the programmatic statements
+                     * below should be taken to be multi-precision, i.e., not
+                     * subject to overflow.
+                     *
+                     * A) Condition guard >= 128:
+                     * If guard >= 128 then first*radix >= 2^7 * 2^57 = 2^64
+                     * hence always overflow.
+                     *
+                     * B) Condition guard < 92:
+                     * Define left7 = first >>> 57.
+                     * Given first = (left7 * 2^57) + (first & (2^57 - 1)) then
+                     * result <= (radix*left7)*2^57 + radix*(2^57 - 1) + second.
+                     * Thus if radix*left7 < 92, radix <= 36, and second < 36,
+                     * then result < 92*2^57 + 36*(2^57 - 1) + 36 = 2^64 hence
+                     * never overflow.
+                     *
+                     * C) Condition 92 <= guard < 128:
+                     * first*radix + second >= radix*left7*2^57 + second
+                     * so that first*radix + second >= 92*2^57 + 0 > 2^63
+                     *
+                     * D) Condition guard < 128:
+                     * radix*first <= (radix*left7) * 2^57 + radix*(2^57 - 1)
+                     * so
+                     * radix*first + second <= (radix*left7) * 2^57 + radix*(2^57 - 1) + 36
+                     * thus
+                     * radix*first + second < 128 * 2^57 + 36*2^57 - radix + 36
+                     * whence
+                     * radix*first + second < 2^64 + 2^6*2^57 = 2^64 + 2^63
+                     *
+                     * E) Conditions C, D, and result >= 0:
+                     * C and D combined imply the mathematical result
+                     * 2^63 < first*radix + second < 2^64 + 2^63. The lower
+                     * bound is therefore negative as a signed long, but the
+                     * upper bound is too small to overflow again after the
+                     * signed long overflows to positive above 2^64 - 1. Hence
+                     * result >= 0 implies overflow given C and D.
+                     */
+                    throw new NumberFormatException(String.format("String value %s exceeds " +
+                            "range of unsigned long.", s.subSequence(start, start + len)));
+                }
+                return result;
+            }
+        } else {
+            throw NumberFormatException.forInputString("", radix);
         }
     }
 
     /**
      * Parses the string argument as an unsigned decimal {@code long}. The
      * characters in the string must all be decimal digits, except
-     * that the first character may be an an ASCII plus sign {@code
+     * that the first character may be an ASCII plus sign {@code
      * '+'} ({@code '\u005Cu002B'}). The resulting integer value
      * is returned, exactly as if the argument and the radix 10 were
      * given as arguments to the {@link
      * #parseUnsignedLong(java.lang.String, int)} method.
      *
      * @param s   a {@code String} containing the unsigned {@code long}
      *            representation to be parsed
      * @return    the unsigned {@code long} value represented by the decimal string argument
      * @throws    NumberFormatException  if the string does not contain a
      *            parsable unsigned integer.
      * @since 1.8
      */
     public static long parseUnsignedLong(String s) throws NumberFormatException {
         return parseUnsignedLong(s, 10);
     }
 
     /**
      * Returns a {@code Long} object holding the value
      * extracted from the specified {@code String} when parsed
      * with the radix given by the second argument.  The first
      * argument is interpreted as representing a signed
      * {@code long} in the radix specified by the second
      * argument, exactly as if the arguments were given to the {@link
      * #parseLong(java.lang.String, int)} method. The result is a
      * {@code Long} object that represents the {@code long}
      * value specified by the string.
      *
      * <p>In other words, this method returns a {@code Long} object equal
      * to the value of:
      *
      * <blockquote>
      *  {@code new Long(Long.parseLong(s, radix))}
      * </blockquote>
      *
      * @param      s       the string to be parsed
      * @param      radix   the radix to be used in interpreting {@code s}
      * @return     a {@code Long} object holding the value
      *             represented by the string argument in the specified
      *             radix.
      * @throws     NumberFormatException  If the {@code String} does not
      *             contain a parsable {@code long}.
      */
     public static Long valueOf(String s, int radix) throws NumberFormatException {
         return Long.valueOf(parseLong(s, radix));
     }
 
     /**
      * Returns a {@code Long} object holding the value
      * of the specified {@code String}. The argument is
      * interpreted as representing a signed decimal {@code long},
      * exactly as if the argument were given to the {@link
      * #parseLong(java.lang.String)} method. The result is a
      * {@code Long} object that represents the integer value
      * specified by the string.
      *
      * <p>In other words, this method returns a {@code Long} object
      * equal to the value of:
      *
      * <blockquote>
      *  {@code new Long(Long.parseLong(s))}
      * </blockquote>
      *
      * @param      s   the string to be parsed.
      * @return     a {@code Long} object holding the value
      *             represented by the string argument.
      * @throws     NumberFormatException  If the string cannot be parsed
      *             as a {@code long}.
      */
     public static Long valueOf(String s) throws NumberFormatException
     {
         return Long.valueOf(parseLong(s, 10));
     }
 
     private static class LongCache {
-        private LongCache(){}
+        private LongCache() {}
 
-        static final Long cache[] = new Long[-(-128) + 127 + 1];
+        static final Long[] cache;
+        static Long[] archivedCache;
 
         static {
-            for(int i = 0; i < cache.length; i++)
-                cache[i] = new Long(i - 128);
+            int size = -(-128) + 127 + 1;
+
+            // Load and use the archived cache if it exists
+            VM.initializeFromArchive(LongCache.class);
+            if (archivedCache == null || archivedCache.length != size) {
+                Long[] c = new Long[size];
+                long value = -128;
+                for(int i = 0; i < size; i++) {
+                    c[i] = new Long(value++);
+                }
+                archivedCache = c;
+            }
+            cache = archivedCache;
         }
     }
 
     /**
      * Returns a {@code Long} instance representing the specified
      * {@code long} value.
      * If a new {@code Long} instance is not required, this method
      * should generally be used in preference to the constructor
      * {@link #Long(long)}, as this method is likely to yield
      * significantly better space and time performance by caching
      * frequently requested values.
      *
-     * Note that unlike the {@linkplain Integer#valueOf(int)
-     * corresponding method} in the {@code Integer} class, this method
-     * is <em>not</em> required to cache values within a particular
-     * range.
+     * This method will always cache values in the range -128 to 127,
+     * inclusive, and may cache other values outside of this range.
      *
      * @param  l a long value.
      * @return a {@code Long} instance representing {@code l}.
      * @since  1.5
      */
+    @HotSpotIntrinsicCandidate
     public static Long valueOf(long l) {
         final int offset = 128;
         if (l >= -128 && l <= 127) { // will cache
             return LongCache.cache[(int)l + offset];
         }
         return new Long(l);
     }
 
     /**
      * Decodes a {@code String} into a {@code Long}.
      * Accepts decimal, hexadecimal, and octal numbers given by the
      * following grammar:
      *
      * <blockquote>
      * <dl>
      * <dt><i>DecodableString:</i>
      * <dd><i>Sign<sub>opt</sub> DecimalNumeral</i>
      * <dd><i>Sign<sub>opt</sub></i> {@code 0x} <i>HexDigits</i>
      * <dd><i>Sign<sub>opt</sub></i> {@code 0X} <i>HexDigits</i>
      * <dd><i>Sign<sub>opt</sub></i> {@code #} <i>HexDigits</i>
      * <dd><i>Sign<sub>opt</sub></i> {@code 0} <i>OctalDigits</i>
      *
      * <dt><i>Sign:</i>
      * <dd>{@code -}
      * <dd>{@code +}
      * </dl>
      * </blockquote>
      *
      * <i>DecimalNumeral</i>, <i>HexDigits</i>, and <i>OctalDigits</i>
      * are as defined in section 3.10.1 of
      * <cite>The Java&trade; Language Specification</cite>,
      * except that underscores are not accepted between digits.
      *
      * <p>The sequence of characters following an optional
      * sign and/or radix specifier ("{@code 0x}", "{@code 0X}",
      * "{@code #}", or leading zero) is parsed as by the {@code
      * Long.parseLong} method with the indicated radix (10, 16, or 8).
      * This sequence of characters must represent a positive value or
      * a {@link NumberFormatException} will be thrown.  The result is
      * negated if first character of the specified {@code String} is
      * the minus sign.  No whitespace characters are permitted in the
      * {@code String}.
      *
      * @param     nm the {@code String} to decode.
      * @return    a {@code Long} object holding the {@code long}
      *            value represented by {@code nm}
      * @throws    NumberFormatException  if the {@code String} does not
      *            contain a parsable {@code long}.
      * @see java.lang.Long#parseLong(String, int)
      * @since 1.2
      */
     public static Long decode(String nm) throws NumberFormatException {
         int radix = 10;
         int index = 0;
         boolean negative = false;
         Long result;
 
-        if (nm.length() == 0)
+        if (nm.isEmpty())
             throw new NumberFormatException("Zero length string");
         char firstChar = nm.charAt(0);
         // Handle sign, if present
         if (firstChar == '-') {
             negative = true;
             index++;
         } else if (firstChar == '+')
             index++;
 
         // Handle radix specifier, if present
         if (nm.startsWith("0x", index) || nm.startsWith("0X", index)) {
             index += 2;
             radix = 16;
         }
         else if (nm.startsWith("#", index)) {
             index ++;
             radix = 16;
         }
         else if (nm.startsWith("0", index) && nm.length() > 1 + index) {
             index ++;
             radix = 8;
         }
 
         if (nm.startsWith("-", index) || nm.startsWith("+", index))
             throw new NumberFormatException("Sign character in wrong position");
 
         try {
             result = Long.valueOf(nm.substring(index), radix);
             result = negative ? Long.valueOf(-result.longValue()) : result;
         } catch (NumberFormatException e) {
             // If number is Long.MIN_VALUE, we'll end up here. The next line
             // handles this case, and causes any genuine format error to be
             // rethrown.
             String constant = negative ? ("-" + nm.substring(index))
                                        : nm.substring(index);
             result = Long.valueOf(constant, radix);
         }
         return result;
     }
 
     /**
      * The value of the {@code Long}.
      *
      * @serial
      */
     private final long value;
 
     /**
      * Constructs a newly allocated {@code Long} object that
      * represents the specified {@code long} argument.
      *
      * @param   value   the value to be represented by the
      *          {@code Long} object.
+     *
+     * @deprecated
+     * It is rarely appropriate to use this constructor. The static factory
+     * {@link #valueOf(long)} is generally a better choice, as it is
+     * likely to yield significantly better space and time performance.
      */
+    @Deprecated(since="9")
     public Long(long value) {
         this.value = value;
     }
 
     /**
      * Constructs a newly allocated {@code Long} object that
      * represents the {@code long} value indicated by the
      * {@code String} parameter. The string is converted to a
      * {@code long} value in exactly the manner used by the
      * {@code parseLong} method for radix 10.
      *
      * @param      s   the {@code String} to be converted to a
      *             {@code Long}.
      * @throws     NumberFormatException  if the {@code String} does not
      *             contain a parsable {@code long}.
-     * @see        java.lang.Long#parseLong(java.lang.String, int)
+     *
+     * @deprecated
+     * It is rarely appropriate to use this constructor.
+     * Use {@link #parseLong(String)} to convert a string to a
+     * {@code long} primitive, or use {@link #valueOf(String)}
+     * to convert a string to a {@code Long} object.
      */
+    @Deprecated(since="9")
     public Long(String s) throws NumberFormatException {
         this.value = parseLong(s, 10);
     }
 
     /**
      * Returns the value of this {@code Long} as a {@code byte} after
      * a narrowing primitive conversion.
      * @jls 5.1.3 Narrowing Primitive Conversions
      */
     public byte byteValue() {
         return (byte)value;
     }
 
     /**
      * Returns the value of this {@code Long} as a {@code short} after
      * a narrowing primitive conversion.
      * @jls 5.1.3 Narrowing Primitive Conversions
      */
     public short shortValue() {
         return (short)value;
     }
 
     /**
      * Returns the value of this {@code Long} as an {@code int} after
      * a narrowing primitive conversion.
      * @jls 5.1.3 Narrowing Primitive Conversions
      */
     public int intValue() {
         return (int)value;
     }
 
     /**
      * Returns the value of this {@code Long} as a
      * {@code long} value.
      */
+    @HotSpotIntrinsicCandidate
     public long longValue() {
         return value;
     }
 
     /**
      * Returns the value of this {@code Long} as a {@code float} after
      * a widening primitive conversion.
      * @jls 5.1.2 Widening Primitive Conversions
      */
     public float floatValue() {
         return (float)value;
     }
 
     /**
      * Returns the value of this {@code Long} as a {@code double}
      * after a widening primitive conversion.
      * @jls 5.1.2 Widening Primitive Conversions
      */
     public double doubleValue() {
         return (double)value;
     }
 
     /**
      * Returns a {@code String} object representing this
      * {@code Long}'s value.  The value is converted to signed
      * decimal representation and returned as a string, exactly as if
      * the {@code long} value were given as an argument to the
      * {@link java.lang.Long#toString(long)} method.
      *
      * @return  a string representation of the value of this object in
      *          base&nbsp;10.
      */
     public String toString() {
         return toString(value);
     }
 
     /**
      * Returns a hash code for this {@code Long}. The result is
      * the exclusive OR of the two halves of the primitive
      * {@code long} value held by this {@code Long}
      * object. That is, the hashcode is the value of the expression:
      *
      * <blockquote>
      *  {@code (int)(this.longValue()^(this.longValue()>>>32))}
      * </blockquote>
      *
      * @return  a hash code value for this object.
      */
     @Override
     public int hashCode() {
         return Long.hashCode(value);
     }
 
     /**
      * Returns a hash code for a {@code long} value; compatible with
      * {@code Long.hashCode()}.
      *
      * @param value the value to hash
      * @return a hash code value for a {@code long} value.
      * @since 1.8
      */
     public static int hashCode(long value) {
         return (int)(value ^ (value >>> 32));
     }
 
     /**
      * Compares this object to the specified object.  The result is
      * {@code true} if and only if the argument is not
      * {@code null} and is a {@code Long} object that
      * contains the same {@code long} value as this object.
      *
      * @param   obj   the object to compare with.
      * @return  {@code true} if the objects are the same;
      *          {@code false} otherwise.
      */
     public boolean equals(Object obj) {
         if (obj instanceof Long) {
             return value == ((Long)obj).longValue();
         }
         return false;
     }
 
     /**
      * Determines the {@code long} value of the system property
      * with the specified name.
      *
      * <p>The first argument is treated as the name of a system
      * property.  System properties are accessible through the {@link
      * java.lang.System#getProperty(java.lang.String)} method. The
      * string value of this property is then interpreted as a {@code
      * long} value using the grammar supported by {@link Long#decode decode}
      * and a {@code Long} object representing this value is returned.
      *
      * <p>If there is no property with the specified name, if the
      * specified name is empty or {@code null}, or if the property
      * does not have the correct numeric format, then {@code null} is
      * returned.
      *
      * <p>In other words, this method returns a {@code Long} object
      * equal to the value of:
      *
      * <blockquote>
      *  {@code getLong(nm, null)}
      * </blockquote>
      *
      * @param   nm   property name.
      * @return  the {@code Long} value of the property.
      * @throws  SecurityException for the same reasons as
      *          {@link System#getProperty(String) System.getProperty}
      * @see     java.lang.System#getProperty(java.lang.String)
      * @see     java.lang.System#getProperty(java.lang.String, java.lang.String)
      */
     public static Long getLong(String nm) {
         return getLong(nm, null);
     }
 
     /**
      * Determines the {@code long} value of the system property
      * with the specified name.
      *
      * <p>The first argument is treated as the name of a system
      * property.  System properties are accessible through the {@link
      * java.lang.System#getProperty(java.lang.String)} method. The
      * string value of this property is then interpreted as a {@code
      * long} value using the grammar supported by {@link Long#decode decode}
      * and a {@code Long} object representing this value is returned.
      *
      * <p>The second argument is the default value. A {@code Long} object
      * that represents the value of the second argument is returned if there
      * is no property of the specified name, if the property does not have
      * the correct numeric format, or if the specified name is empty or null.
      *
      * <p>In other words, this method returns a {@code Long} object equal
      * to the value of:
      *
      * <blockquote>
      *  {@code getLong(nm, new Long(val))}
      * </blockquote>
      *
      * but in practice it may be implemented in a manner such as:
      *
      * <blockquote><pre>
      * Long result = getLong(nm, null);
      * return (result == null) ? new Long(val) : result;
      * </pre></blockquote>
      *
      * to avoid the unnecessary allocation of a {@code Long} object when
      * the default value is not needed.
      *
      * @param   nm    property name.
      * @param   val   default value.
      * @return  the {@code Long} value of the property.
      * @throws  SecurityException for the same reasons as
      *          {@link System#getProperty(String) System.getProperty}
      * @see     java.lang.System#getProperty(java.lang.String)
      * @see     java.lang.System#getProperty(java.lang.String, java.lang.String)
      */
     public static Long getLong(String nm, long val) {
         Long result = Long.getLong(nm, null);
         return (result == null) ? Long.valueOf(val) : result;
     }
 
     /**
      * Returns the {@code long} value of the system property with
      * the specified name.  The first argument is treated as the name
      * of a system property.  System properties are accessible through
      * the {@link java.lang.System#getProperty(java.lang.String)}
      * method. The string value of this property is then interpreted
      * as a {@code long} value, as per the
      * {@link Long#decode decode} method, and a {@code Long} object
      * representing this value is returned; in summary:
      *
      * <ul>
      * <li>If the property value begins with the two ASCII characters
      * {@code 0x} or the ASCII character {@code #}, not followed by
      * a minus sign, then the rest of it is parsed as a hexadecimal integer
      * exactly as for the method {@link #valueOf(java.lang.String, int)}
      * with radix 16.
      * <li>If the property value begins with the ASCII character
      * {@code 0} followed by another character, it is parsed as
      * an octal integer exactly as by the method {@link
      * #valueOf(java.lang.String, int)} with radix 8.
      * <li>Otherwise the property value is parsed as a decimal
      * integer exactly as by the method
      * {@link #valueOf(java.lang.String, int)} with radix 10.
      * </ul>
      *
      * <p>Note that, in every case, neither {@code L}
      * ({@code '\u005Cu004C'}) nor {@code l}
      * ({@code '\u005Cu006C'}) is permitted to appear at the end
      * of the property value as a type indicator, as would be
      * permitted in Java programming language source code.
      *
      * <p>The second argument is the default value. The default value is
      * returned if there is no property of the specified name, if the
      * property does not have the correct numeric format, or if the
      * specified name is empty or {@code null}.
      *
      * @param   nm   property name.
      * @param   val   default value.
      * @return  the {@code Long} value of the property.
      * @throws  SecurityException for the same reasons as
      *          {@link System#getProperty(String) System.getProperty}
      * @see     System#getProperty(java.lang.String)
      * @see     System#getProperty(java.lang.String, java.lang.String)
      */
     public static Long getLong(String nm, Long val) {
         String v = null;
         try {
             v = System.getProperty(nm);
         } catch (IllegalArgumentException | NullPointerException e) {
         }
         if (v != null) {
             try {
                 return Long.decode(v);
             } catch (NumberFormatException e) {
             }
         }
         return val;
     }
 
     /**
      * Compares two {@code Long} objects numerically.
      *
      * @param   anotherLong   the {@code Long} to be compared.
      * @return  the value {@code 0} if this {@code Long} is
      *          equal to the argument {@code Long}; a value less than
      *          {@code 0} if this {@code Long} is numerically less
      *          than the argument {@code Long}; and a value greater
      *          than {@code 0} if this {@code Long} is numerically
      *           greater than the argument {@code Long} (signed
      *           comparison).
      * @since   1.2
      */
     public int compareTo(Long anotherLong) {
         return compare(this.value, anotherLong.value);
     }
 
     /**
      * Compares two {@code long} values numerically.
      * The value returned is identical to what would be returned by:
      * <pre>
      *    Long.valueOf(x).compareTo(Long.valueOf(y))
      * </pre>
      *
      * @param  x the first {@code long} to compare
      * @param  y the second {@code long} to compare
      * @return the value {@code 0} if {@code x == y};
      *         a value less than {@code 0} if {@code x < y}; and
      *         a value greater than {@code 0} if {@code x > y}
      * @since 1.7
      */
     public static int compare(long x, long y) {
         return (x < y) ? -1 : ((x == y) ? 0 : 1);
     }
 
     /**
      * Compares two {@code long} values numerically treating the values
      * as unsigned.
      *
      * @param  x the first {@code long} to compare
      * @param  y the second {@code long} to compare
      * @return the value {@code 0} if {@code x == y}; a value less
      *         than {@code 0} if {@code x < y} as unsigned values; and
      *         a value greater than {@code 0} if {@code x > y} as
      *         unsigned values
      * @since 1.8
      */
     public static int compareUnsigned(long x, long y) {
         return compare(x + MIN_VALUE, y + MIN_VALUE);
     }
 
 
     /**
      * Returns the unsigned quotient of dividing the first argument by
      * the second where each argument and the result is interpreted as
      * an unsigned value.
      *
      * <p>Note that in two's complement arithmetic, the three other
      * basic arithmetic operations of add, subtract, and multiply are
      * bit-wise identical if the two operands are regarded as both
      * being signed or both being unsigned.  Therefore separate {@code
      * addUnsigned}, etc. methods are not provided.
      *
      * @param dividend the value to be divided
      * @param divisor the value doing the dividing
      * @return the unsigned quotient of the first argument divided by
      * the second argument
      * @see #remainderUnsigned
      * @since 1.8
      */
     public static long divideUnsigned(long dividend, long divisor) {
         if (divisor < 0L) { // signed comparison
             // Answer must be 0 or 1 depending on relative magnitude
             // of dividend and divisor.
             return (compareUnsigned(dividend, divisor)) < 0 ? 0L :1L;
         }
 
         if (dividend > 0) //  Both inputs non-negative
             return dividend/divisor;
         else {
             /*
              * For simple code, leveraging BigInteger.  Longer and faster
              * code written directly in terms of operations on longs is
              * possible; see "Hacker's Delight" for divide and remainder
              * algorithms.
              */
             return toUnsignedBigInteger(dividend).
                 divide(toUnsignedBigInteger(divisor)).longValue();
         }
     }
 
     /**
      * Returns the unsigned remainder from dividing the first argument
      * by the second where each argument and the result is interpreted
      * as an unsigned value.
      *
      * @param dividend the value to be divided
      * @param divisor the value doing the dividing
      * @return the unsigned remainder of the first argument divided by
      * the second argument
      * @see #divideUnsigned
      * @since 1.8
      */
     public static long remainderUnsigned(long dividend, long divisor) {
         if (dividend > 0 && divisor > 0) { // signed comparisons
             return dividend % divisor;
         } else {
             if (compareUnsigned(dividend, divisor) < 0) // Avoid explicit check for 0 divisor
                 return dividend;
             else
                 return toUnsignedBigInteger(dividend).
                     remainder(toUnsignedBigInteger(divisor)).longValue();
         }
     }
 
     // Bit Twiddling
 
     /**
      * The number of bits used to represent a {@code long} value in two's
      * complement binary form.
      *
      * @since 1.5
      */
     @Native public static final int SIZE = 64;
 
     /**
      * The number of bytes used to represent a {@code long} value in two's
      * complement binary form.
      *
      * @since 1.8
      */
     public static final int BYTES = SIZE / Byte.SIZE;
 
     /**
      * Returns a {@code long} value with at most a single one-bit, in the
      * position of the highest-order ("leftmost") one-bit in the specified
      * {@code long} value.  Returns zero if the specified value has no
      * one-bits in its two's complement binary representation, that is, if it
      * is equal to zero.
      *
      * @param i the value whose highest one bit is to be computed
      * @return a {@code long} value with a single one-bit, in the position
      *     of the highest-order one-bit in the specified value, or zero if
      *     the specified value is itself equal to zero.
      * @since 1.5
      */
     public static long highestOneBit(long i) {
-        // HD, Figure 3-1
-        i |= (i >>  1);
-        i |= (i >>  2);
-        i |= (i >>  4);
-        i |= (i >>  8);
-        i |= (i >> 16);
-        i |= (i >> 32);
-        return i - (i >>> 1);
+        return i & (MIN_VALUE >>> numberOfLeadingZeros(i));
     }
 
     /**
      * Returns a {@code long} value with at most a single one-bit, in the
      * position of the lowest-order ("rightmost") one-bit in the specified
      * {@code long} value.  Returns zero if the specified value has no
      * one-bits in its two's complement binary representation, that is, if it
      * is equal to zero.
      *
      * @param i the value whose lowest one bit is to be computed
      * @return a {@code long} value with a single one-bit, in the position
      *     of the lowest-order one-bit in the specified value, or zero if
      *     the specified value is itself equal to zero.
      * @since 1.5
      */
     public static long lowestOneBit(long i) {
         // HD, Section 2-1
         return i & -i;
     }
 
     /**
      * Returns the number of zero bits preceding the highest-order
      * ("leftmost") one-bit in the two's complement binary representation
      * of the specified {@code long} value.  Returns 64 if the
      * specified value has no one-bits in its two's complement representation,
      * in other words if it is equal to zero.
      *
      * <p>Note that this method is closely related to the logarithm base 2.
      * For all positive {@code long} values x:
      * <ul>
      * <li>floor(log<sub>2</sub>(x)) = {@code 63 - numberOfLeadingZeros(x)}
      * <li>ceil(log<sub>2</sub>(x)) = {@code 64 - numberOfLeadingZeros(x - 1)}
      * </ul>
      *
      * @param i the value whose number of leading zeros is to be computed
      * @return the number of zero bits preceding the highest-order
      *     ("leftmost") one-bit in the two's complement binary representation
      *     of the specified {@code long} value, or 64 if the value
      *     is equal to zero.
      * @since 1.5
      */
+    @HotSpotIntrinsicCandidate
     public static int numberOfLeadingZeros(long i) {
-        // HD, Figure 5-6
-         if (i == 0)
-            return 64;
-        int n = 1;
         int x = (int)(i >>> 32);
-        if (x == 0) { n += 32; x = (int)i; }
-        if (x >>> 16 == 0) { n += 16; x <<= 16; }
-        if (x >>> 24 == 0) { n +=  8; x <<=  8; }
-        if (x >>> 28 == 0) { n +=  4; x <<=  4; }
-        if (x >>> 30 == 0) { n +=  2; x <<=  2; }
-        n -= x >>> 31;
-        return n;
+        return x == 0 ? 32 + Integer.numberOfLeadingZeros((int)i)
+                : Integer.numberOfLeadingZeros(x);
     }
 
     /**
      * Returns the number of zero bits following the lowest-order ("rightmost")
      * one-bit in the two's complement binary representation of the specified
      * {@code long} value.  Returns 64 if the specified value has no
      * one-bits in its two's complement representation, in other words if it is
      * equal to zero.
      *
      * @param i the value whose number of trailing zeros is to be computed
      * @return the number of zero bits following the lowest-order ("rightmost")
      *     one-bit in the two's complement binary representation of the
      *     specified {@code long} value, or 64 if the value is equal
      *     to zero.
      * @since 1.5
      */
+    @HotSpotIntrinsicCandidate
     public static int numberOfTrailingZeros(long i) {
-        // HD, Figure 5-14
-        int x, y;
-        if (i == 0) return 64;
-        int n = 63;
-        y = (int)i; if (y != 0) { n = n -32; x = y; } else x = (int)(i>>>32);
-        y = x <<16; if (y != 0) { n = n -16; x = y; }
-        y = x << 8; if (y != 0) { n = n - 8; x = y; }
-        y = x << 4; if (y != 0) { n = n - 4; x = y; }
-        y = x << 2; if (y != 0) { n = n - 2; x = y; }
-        return n - ((x << 1) >>> 31);
+        int x = (int)i;
+        return x == 0 ? 32 + Integer.numberOfTrailingZeros((int)(i >>> 32))
+                : Integer.numberOfTrailingZeros(x);
     }
 
     /**
      * Returns the number of one-bits in the two's complement binary
      * representation of the specified {@code long} value.  This function is
      * sometimes referred to as the <i>population count</i>.
      *
      * @param i the value whose bits are to be counted
      * @return the number of one-bits in the two's complement binary
      *     representation of the specified {@code long} value.
      * @since 1.5
      */
+     @HotSpotIntrinsicCandidate
      public static int bitCount(long i) {
-        // HD, Figure 5-14
+        // HD, Figure 5-2
         i = i - ((i >>> 1) & 0x5555555555555555L);
         i = (i & 0x3333333333333333L) + ((i >>> 2) & 0x3333333333333333L);
         i = (i + (i >>> 4)) & 0x0f0f0f0f0f0f0f0fL;
         i = i + (i >>> 8);
         i = i + (i >>> 16);
         i = i + (i >>> 32);
         return (int)i & 0x7f;
      }
 
     /**
      * Returns the value obtained by rotating the two's complement binary
      * representation of the specified {@code long} value left by the
      * specified number of bits.  (Bits shifted out of the left hand, or
      * high-order, side reenter on the right, or low-order.)
      *
      * <p>Note that left rotation with a negative distance is equivalent to
      * right rotation: {@code rotateLeft(val, -distance) == rotateRight(val,
      * distance)}.  Note also that rotation by any multiple of 64 is a
      * no-op, so all but the last six bits of the rotation distance can be
      * ignored, even if the distance is negative: {@code rotateLeft(val,
      * distance) == rotateLeft(val, distance & 0x3F)}.
      *
      * @param i the value whose bits are to be rotated left
      * @param distance the number of bit positions to rotate left
      * @return the value obtained by rotating the two's complement binary
      *     representation of the specified {@code long} value left by the
      *     specified number of bits.
      * @since 1.5
      */
     public static long rotateLeft(long i, int distance) {
         return (i << distance) | (i >>> -distance);
     }
 
     /**
      * Returns the value obtained by rotating the two's complement binary
      * representation of the specified {@code long} value right by the
      * specified number of bits.  (Bits shifted out of the right hand, or
      * low-order, side reenter on the left, or high-order.)
      *
      * <p>Note that right rotation with a negative distance is equivalent to
      * left rotation: {@code rotateRight(val, -distance) == rotateLeft(val,
      * distance)}.  Note also that rotation by any multiple of 64 is a
      * no-op, so all but the last six bits of the rotation distance can be
      * ignored, even if the distance is negative: {@code rotateRight(val,
      * distance) == rotateRight(val, distance & 0x3F)}.
      *
      * @param i the value whose bits are to be rotated right
      * @param distance the number of bit positions to rotate right
      * @return the value obtained by rotating the two's complement binary
      *     representation of the specified {@code long} value right by the
      *     specified number of bits.
      * @since 1.5
      */
     public static long rotateRight(long i, int distance) {
         return (i >>> distance) | (i << -distance);
     }
 
     /**
      * Returns the value obtained by reversing the order of the bits in the
      * two's complement binary representation of the specified {@code long}
      * value.
      *
      * @param i the value to be reversed
      * @return the value obtained by reversing order of the bits in the
      *     specified {@code long} value.
      * @since 1.5
      */
     public static long reverse(long i) {
         // HD, Figure 7-1
         i = (i & 0x5555555555555555L) << 1 | (i >>> 1) & 0x5555555555555555L;
         i = (i & 0x3333333333333333L) << 2 | (i >>> 2) & 0x3333333333333333L;
         i = (i & 0x0f0f0f0f0f0f0f0fL) << 4 | (i >>> 4) & 0x0f0f0f0f0f0f0f0fL;
-        i = (i & 0x00ff00ff00ff00ffL) << 8 | (i >>> 8) & 0x00ff00ff00ff00ffL;
-        i = (i << 48) | ((i & 0xffff0000L) << 16) |
-            ((i >>> 16) & 0xffff0000L) | (i >>> 48);
-        return i;
+
+        return reverseBytes(i);
     }
 
     /**
      * Returns the signum function of the specified {@code long} value.  (The
      * return value is -1 if the specified value is negative; 0 if the
      * specified value is zero; and 1 if the specified value is positive.)
      *
      * @param i the value whose signum is to be computed
      * @return the signum function of the specified {@code long} value.
      * @since 1.5
      */
     public static int signum(long i) {
         // HD, Section 2-7
         return (int) ((i >> 63) | (-i >>> 63));
     }
 
     /**
      * Returns the value obtained by reversing the order of the bytes in the
      * two's complement representation of the specified {@code long} value.
      *
      * @param i the value whose bytes are to be reversed
      * @return the value obtained by reversing the bytes in the specified
      *     {@code long} value.
      * @since 1.5
      */
+    @HotSpotIntrinsicCandidate
     public static long reverseBytes(long i) {
         i = (i & 0x00ff00ff00ff00ffL) << 8 | (i >>> 8) & 0x00ff00ff00ff00ffL;
         return (i << 48) | ((i & 0xffff0000L) << 16) |
             ((i >>> 16) & 0xffff0000L) | (i >>> 48);
     }
 
     /**
      * Adds two {@code long} values together as per the + operator.
      *
      * @param a the first operand
      * @param b the second operand
      * @return the sum of {@code a} and {@code b}
      * @see java.util.function.BinaryOperator
      * @since 1.8
      */
     public static long sum(long a, long b) {
         return a + b;
     }
 
     /**
      * Returns the greater of two {@code long} values
      * as if by calling {@link Math#max(long, long) Math.max}.
      *
      * @param a the first operand
      * @param b the second operand
      * @return the greater of {@code a} and {@code b}
      * @see java.util.function.BinaryOperator
      * @since 1.8
      */
     public static long max(long a, long b) {
         return Math.max(a, b);
     }
 
     /**
      * Returns the smaller of two {@code long} values
      * as if by calling {@link Math#min(long, long) Math.min}.
      *
      * @param a the first operand
      * @param b the second operand
      * @return the smaller of {@code a} and {@code b}
      * @see java.util.function.BinaryOperator
      * @since 1.8
      */
     public static long min(long a, long b) {
         return Math.min(a, b);
     }
 
+    /**
+     * Returns an {@link Optional} containing the nominal descriptor for this
+     * instance, which is the instance itself.
+     *
+     * @return an {@link Optional} describing the {@linkplain Long} instance
+     * @since 12
+     */
+    @Override
+    public Optional<Long> describeConstable() {
+        return Optional.of(this);
+    }
+
+    /**
+     * Resolves this instance as a {@link ConstantDesc}, the result of which is
+     * the instance itself.
+     *
+     * @param lookup ignored
+     * @return the {@linkplain Long} instance
+     * @since 12
+     */
+    @Override
+    public Long resolveConstantDesc(MethodHandles.Lookup lookup) {
+        return this;
+    }
+
     /** use serialVersionUID from JDK 1.0.2 for interoperability */
     @Native private static final long serialVersionUID = 4290774380558885855L;
 }