jaroslav@67: /* jaroslav@67: * Copyright (c) 1994, 2009, Oracle and/or its affiliates. All rights reserved. jaroslav@67: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. jaroslav@67: * jaroslav@67: * This code is free software; you can redistribute it and/or modify it jaroslav@67: * under the terms of the GNU General Public License version 2 only, as jaroslav@67: * published by the Free Software Foundation. Oracle designates this jaroslav@67: * particular file as subject to the "Classpath" exception as provided jaroslav@67: * by Oracle in the LICENSE file that accompanied this code. jaroslav@67: * jaroslav@67: * This code is distributed in the hope that it will be useful, but WITHOUT jaroslav@67: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or jaroslav@67: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License jaroslav@67: * version 2 for more details (a copy is included in the LICENSE file that jaroslav@67: * accompanied this code). jaroslav@67: * jaroslav@67: * You should have received a copy of the GNU General Public License version jaroslav@67: * 2 along with this work; if not, write to the Free Software Foundation, jaroslav@67: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. jaroslav@67: * jaroslav@67: * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA jaroslav@67: * or visit www.oracle.com if you need additional information or have any jaroslav@67: * questions. jaroslav@67: */ jaroslav@67: jaroslav@67: package java.lang; jaroslav@67: jaroslav@179: import org.apidesign.bck2brwsr.core.JavaScriptBody; jaroslav@179: jaroslav@67: /** jaroslav@67: * The {@code Long} class wraps a value of the primitive type {@code jaroslav@67: * long} in an object. An object of type {@code Long} contains a jaroslav@67: * single field whose type is {@code long}. jaroslav@67: * jaroslav@67: *
In addition, this class provides several methods for converting jaroslav@67: * a {@code long} to a {@code String} and a {@code String} to a {@code jaroslav@67: * long}, as well as other constants and methods useful when dealing jaroslav@67: * with a {@code long}. jaroslav@67: * jaroslav@67: *
Implementation note: The implementations of the "bit twiddling"
jaroslav@67: * methods (such as {@link #highestOneBit(long) highestOneBit} and
jaroslav@67: * {@link #numberOfTrailingZeros(long) numberOfTrailingZeros}) are
jaroslav@67: * based on material from Henry S. Warren, Jr.'s Hacker's
jaroslav@67: * Delight, (Addison Wesley, 2002).
jaroslav@67: *
jaroslav@67: * @author Lee Boynton
jaroslav@67: * @author Arthur van Hoff
jaroslav@67: * @author Josh Bloch
jaroslav@67: * @author Joseph D. Darcy
jaroslav@67: * @since JDK1.0
jaroslav@67: */
jaroslav@67: public final class Long extends Number implements Comparable If the radix is smaller than {@code Character.MIN_RADIX}
jaroslav@67: * or larger than {@code Character.MAX_RADIX}, then the radix
jaroslav@67: * {@code 10} is used instead.
jaroslav@67: *
jaroslav@67: * If the first argument is negative, the first element of the
jaroslav@67: * result is the ASCII minus sign {@code '-'}
jaroslav@67: * ( The remaining characters of the result represent the magnitude
jaroslav@67: * of the first argument. If the magnitude is zero, it is
jaroslav@67: * represented by a single zero character {@code '0'}
jaroslav@67: * ( The unsigned {@code long} value is the argument plus
jaroslav@67: * 264 if the argument is negative; otherwise, it is
jaroslav@67: * equal to the argument. This value is converted to a string of
jaroslav@67: * ASCII digits in hexadecimal (base 16) with no extra
jaroslav@67: * leading {@code 0}s. If the unsigned magnitude is zero, it
jaroslav@67: * is represented by a single zero character {@code '0'}
jaroslav@67: * ( The unsigned {@code long} value is the argument plus
jaroslav@67: * 264 if the argument is negative; otherwise, it is
jaroslav@67: * equal to the argument. This value is converted to a string of
jaroslav@67: * ASCII digits in octal (base 8) with no extra leading
jaroslav@67: * {@code 0}s.
jaroslav@67: *
jaroslav@67: * If the unsigned magnitude is zero, it is represented by a
jaroslav@67: * single zero character {@code '0'}
jaroslav@67: * ( The unsigned {@code long} value is the argument plus
jaroslav@67: * 264 if the argument is negative; otherwise, it is
jaroslav@67: * equal to the argument. This value is converted to a string of
jaroslav@67: * ASCII digits in binary (base 2) with no extra leading
jaroslav@67: * {@code 0}s. If the unsigned magnitude is zero, it is
jaroslav@67: * represented by a single zero character {@code '0'}
jaroslav@67: * ( Note that neither the character {@code L}
jaroslav@67: * ( An exception of type {@code NumberFormatException} is
jaroslav@67: * thrown if any of the following situations occurs:
jaroslav@67: * Examples:
jaroslav@67: * Note that neither the character {@code L}
jaroslav@67: * ( In other words, this method returns a {@code Long} object equal
jaroslav@67: * to the value of:
jaroslav@67: *
jaroslav@67: * In other words, this method returns a {@code Long} object
jaroslav@67: * equal to the value of:
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * The sequence of characters following an optional
jaroslav@67: * sign and/or radix specifier ("{@code 0x}", "{@code 0X}",
jaroslav@67: * "{@code #}", or leading zero) is parsed as by the {@code
jaroslav@67: * Long.parseLong} method with the indicated radix (10, 16, or 8).
jaroslav@67: * This sequence of characters must represent a positive value or
jaroslav@67: * a {@link NumberFormatException} will be thrown. The result is
jaroslav@67: * negated if first character of the specified {@code String} is
jaroslav@67: * the minus sign. No whitespace characters are permitted in the
jaroslav@67: * {@code String}.
jaroslav@67: *
jaroslav@67: * @param nm the {@code String} to decode.
jaroslav@67: * @return a {@code Long} object holding the {@code long}
jaroslav@67: * value represented by {@code nm}
jaroslav@67: * @throws NumberFormatException if the {@code String} does not
jaroslav@67: * contain a parsable {@code long}.
jaroslav@67: * @see java.lang.Long#parseLong(String, int)
jaroslav@67: * @since 1.2
jaroslav@67: */
jaroslav@67: public static Long decode(String nm) throws NumberFormatException {
jaroslav@67: int radix = 10;
jaroslav@67: int index = 0;
jaroslav@67: boolean negative = false;
jaroslav@67: Long result;
jaroslav@67:
jaroslav@67: if (nm.length() == 0)
jaroslav@67: throw new NumberFormatException("Zero length string");
jaroslav@67: char firstChar = nm.charAt(0);
jaroslav@67: // Handle sign, if present
jaroslav@67: if (firstChar == '-') {
jaroslav@67: negative = true;
jaroslav@67: index++;
jaroslav@67: } else if (firstChar == '+')
jaroslav@67: index++;
jaroslav@67:
jaroslav@67: // Handle radix specifier, if present
jaroslav@67: if (nm.startsWith("0x", index) || nm.startsWith("0X", index)) {
jaroslav@67: index += 2;
jaroslav@67: radix = 16;
jaroslav@67: }
jaroslav@67: else if (nm.startsWith("#", index)) {
jaroslav@67: index ++;
jaroslav@67: radix = 16;
jaroslav@67: }
jaroslav@67: else if (nm.startsWith("0", index) && nm.length() > 1 + index) {
jaroslav@67: index ++;
jaroslav@67: radix = 8;
jaroslav@67: }
jaroslav@67:
jaroslav@67: if (nm.startsWith("-", index) || nm.startsWith("+", index))
jaroslav@67: throw new NumberFormatException("Sign character in wrong position");
jaroslav@67:
jaroslav@67: try {
jaroslav@67: result = Long.valueOf(nm.substring(index), radix);
jaroslav@67: result = negative ? Long.valueOf(-result.longValue()) : result;
jaroslav@67: } catch (NumberFormatException e) {
jaroslav@67: // If number is Long.MIN_VALUE, we'll end up here. The next line
jaroslav@67: // handles this case, and causes any genuine format error to be
jaroslav@67: // rethrown.
jaroslav@67: String constant = negative ? ("-" + nm.substring(index))
jaroslav@67: : nm.substring(index);
jaroslav@67: result = Long.valueOf(constant, radix);
jaroslav@67: }
jaroslav@67: return result;
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * The value of the {@code Long}.
jaroslav@67: *
jaroslav@67: * @serial
jaroslav@67: */
jaroslav@67: private final long value;
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Constructs a newly allocated {@code Long} object that
jaroslav@67: * represents the specified {@code long} argument.
jaroslav@67: *
jaroslav@67: * @param value the value to be represented by the
jaroslav@67: * {@code Long} object.
jaroslav@67: */
jaroslav@67: public Long(long value) {
jaroslav@67: this.value = value;
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Constructs a newly allocated {@code Long} object that
jaroslav@67: * represents the {@code long} value indicated by the
jaroslav@67: * {@code String} parameter. The string is converted to a
jaroslav@67: * {@code long} value in exactly the manner used by the
jaroslav@67: * {@code parseLong} method for radix 10.
jaroslav@67: *
jaroslav@67: * @param s the {@code String} to be converted to a
jaroslav@67: * {@code Long}.
jaroslav@67: * @throws NumberFormatException if the {@code String} does not
jaroslav@67: * contain a parsable {@code long}.
jaroslav@67: * @see java.lang.Long#parseLong(java.lang.String, int)
jaroslav@67: */
jaroslav@67: public Long(String s) throws NumberFormatException {
jaroslav@67: this.value = parseLong(s, 10);
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns the value of this {@code Long} as a
jaroslav@67: * {@code byte}.
jaroslav@67: */
jaroslav@67: public byte byteValue() {
jaroslav@67: return (byte)value;
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns the value of this {@code Long} as a
jaroslav@67: * {@code short}.
jaroslav@67: */
jaroslav@67: public short shortValue() {
jaroslav@67: return (short)value;
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns the value of this {@code Long} as an
jaroslav@67: * {@code int}.
jaroslav@67: */
jaroslav@67: public int intValue() {
jaroslav@67: return (int)value;
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns the value of this {@code Long} as a
jaroslav@67: * {@code long} value.
jaroslav@67: */
jaroslav@67: public long longValue() {
jaroslav@67: return (long)value;
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns the value of this {@code Long} as a
jaroslav@67: * {@code float}.
jaroslav@67: */
jaroslav@67: public float floatValue() {
jaroslav@67: return (float)value;
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns the value of this {@code Long} as a
jaroslav@67: * {@code double}.
jaroslav@67: */
jaroslav@67: public double doubleValue() {
jaroslav@67: return (double)value;
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns a {@code String} object representing this
jaroslav@67: * {@code Long}'s value. The value is converted to signed
jaroslav@67: * decimal representation and returned as a string, exactly as if
jaroslav@67: * the {@code long} value were given as an argument to the
jaroslav@67: * {@link java.lang.Long#toString(long)} method.
jaroslav@67: *
jaroslav@67: * @return a string representation of the value of this object in
jaroslav@67: * base 10.
jaroslav@67: */
jaroslav@67: public String toString() {
jaroslav@67: return toString(value);
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns a hash code for this {@code Long}. The result is
jaroslav@67: * the exclusive OR of the two halves of the primitive
jaroslav@67: * {@code long} value held by this {@code Long}
jaroslav@67: * object. That is, the hashcode is the value of the expression:
jaroslav@67: *
jaroslav@67: * The first argument is treated as the name of a system property.
jaroslav@67: * System properties are accessible through the {@link
jaroslav@67: * java.lang.System#getProperty(java.lang.String)} method. The
jaroslav@67: * string value of this property is then interpreted as a
jaroslav@67: * {@code long} value and a {@code Long} object
jaroslav@67: * representing this value is returned. Details of possible
jaroslav@67: * numeric formats can be found with the definition of
jaroslav@67: * {@code getProperty}.
jaroslav@67: *
jaroslav@67: * If there is no property with the specified name, if the
jaroslav@67: * specified name is empty or {@code null}, or if the
jaroslav@67: * property does not have the correct numeric format, then
jaroslav@67: * {@code null} is returned.
jaroslav@67: *
jaroslav@67: * In other words, this method returns a {@code Long} object equal to
jaroslav@67: * the value of:
jaroslav@67: *
jaroslav@67: * The first argument is treated as the name of a system property.
jaroslav@67: * System properties are accessible through the {@link
jaroslav@67: * java.lang.System#getProperty(java.lang.String)} method. The
jaroslav@67: * string value of this property is then interpreted as a
jaroslav@67: * {@code long} value and a {@code Long} object
jaroslav@67: * representing this value is returned. Details of possible
jaroslav@67: * numeric formats can be found with the definition of
jaroslav@67: * {@code getProperty}.
jaroslav@67: *
jaroslav@67: * The second argument is the default value. A {@code Long} object
jaroslav@67: * that represents the value of the second argument is returned if there
jaroslav@67: * is no property of the specified name, if the property does not have
jaroslav@67: * the correct numeric format, or if the specified name is empty or null.
jaroslav@67: *
jaroslav@67: * In other words, this method returns a {@code Long} object equal
jaroslav@67: * to the value of:
jaroslav@67: *
jaroslav@67: * Note that, in every case, neither {@code L}
jaroslav@67: * ( The second argument is the default value. The default value is
jaroslav@67: * returned if there is no property of the specified name, if the
jaroslav@67: * property does not have the correct numeric format, or if the
jaroslav@67: * specified name is empty or {@code null}.
jaroslav@67: *
jaroslav@67: * @param nm property name.
jaroslav@67: * @param val default value.
jaroslav@67: * @return the {@code Long} value of the property.
jaroslav@67: * @see java.lang.System#getProperty(java.lang.String)
jaroslav@67: * @see java.lang.System#getProperty(java.lang.String, java.lang.String)
jaroslav@67: * @see java.lang.Long#decode
jaroslav@67: */
jaroslav@67: public static Long getLong(String nm, Long val) {
jaroslav@67: String v = null;
jaroslav@67: try {
jaroslav@104: v = AbstractStringBuilder.getProperty(nm);
jaroslav@67: } catch (IllegalArgumentException e) {
jaroslav@67: } catch (NullPointerException e) {
jaroslav@67: }
jaroslav@67: if (v != null) {
jaroslav@67: try {
jaroslav@67: return Long.decode(v);
jaroslav@67: } catch (NumberFormatException e) {
jaroslav@67: }
jaroslav@67: }
jaroslav@67: return val;
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Compares two {@code Long} objects numerically.
jaroslav@67: *
jaroslav@67: * @param anotherLong the {@code Long} to be compared.
jaroslav@67: * @return the value {@code 0} if this {@code Long} is
jaroslav@67: * equal to the argument {@code Long}; a value less than
jaroslav@67: * {@code 0} if this {@code Long} is numerically less
jaroslav@67: * than the argument {@code Long}; and a value greater
jaroslav@67: * than {@code 0} if this {@code Long} is numerically
jaroslav@67: * greater than the argument {@code Long} (signed
jaroslav@67: * comparison).
jaroslav@67: * @since 1.2
jaroslav@67: */
jaroslav@67: public int compareTo(Long anotherLong) {
jaroslav@67: return compare(this.value, anotherLong.value);
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Compares two {@code long} values numerically.
jaroslav@67: * The value returned is identical to what would be returned by:
jaroslav@67: * Note that this method is closely related to the logarithm base 2.
jaroslav@67: * For all positive {@code long} values x:
jaroslav@67: * Note that left rotation with a negative distance is equivalent to
jaroslav@67: * right rotation: {@code rotateLeft(val, -distance) == rotateRight(val,
jaroslav@67: * distance)}. Note also that rotation by any multiple of 64 is a
jaroslav@67: * no-op, so all but the last six bits of the rotation distance can be
jaroslav@67: * ignored, even if the distance is negative: {@code rotateLeft(val,
jaroslav@67: * distance) == rotateLeft(val, distance & 0x3F)}.
jaroslav@67: *
jaroslav@67: * @return the value obtained by rotating the two's complement binary
jaroslav@67: * representation of the specified {@code long} value left by the
jaroslav@67: * specified number of bits.
jaroslav@67: * @since 1.5
jaroslav@67: */
jaroslav@67: public static long rotateLeft(long i, int distance) {
jaroslav@67: return (i << distance) | (i >>> -distance);
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns the value obtained by rotating the two's complement binary
jaroslav@67: * representation of the specified {@code long} value right by the
jaroslav@67: * specified number of bits. (Bits shifted out of the right hand, or
jaroslav@67: * low-order, side reenter on the left, or high-order.)
jaroslav@67: *
jaroslav@67: * Note that right rotation with a negative distance is equivalent to
jaroslav@67: * left rotation: {@code rotateRight(val, -distance) == rotateLeft(val,
jaroslav@67: * distance)}. Note also that rotation by any multiple of 64 is a
jaroslav@67: * no-op, so all but the last six bits of the rotation distance can be
jaroslav@67: * ignored, even if the distance is negative: {@code rotateRight(val,
jaroslav@67: * distance) == rotateRight(val, distance & 0x3F)}.
jaroslav@67: *
jaroslav@67: * @return the value obtained by rotating the two's complement binary
jaroslav@67: * representation of the specified {@code long} value right by the
jaroslav@67: * specified number of bits.
jaroslav@67: * @since 1.5
jaroslav@67: */
jaroslav@67: public static long rotateRight(long i, int distance) {
jaroslav@67: return (i >>> distance) | (i << -distance);
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns the value obtained by reversing the order of the bits in the
jaroslav@67: * two's complement binary representation of the specified {@code long}
jaroslav@67: * value.
jaroslav@67: *
jaroslav@67: * @return the value obtained by reversing order of the bits in the
jaroslav@67: * specified {@code long} value.
jaroslav@67: * @since 1.5
jaroslav@67: */
jaroslav@67: public static long reverse(long i) {
jaroslav@67: // HD, Figure 7-1
jaroslav@67: i = (i & 0x5555555555555555L) << 1 | (i >>> 1) & 0x5555555555555555L;
jaroslav@67: i = (i & 0x3333333333333333L) << 2 | (i >>> 2) & 0x3333333333333333L;
jaroslav@67: i = (i & 0x0f0f0f0f0f0f0f0fL) << 4 | (i >>> 4) & 0x0f0f0f0f0f0f0f0fL;
jaroslav@67: i = (i & 0x00ff00ff00ff00ffL) << 8 | (i >>> 8) & 0x00ff00ff00ff00ffL;
jaroslav@67: i = (i << 48) | ((i & 0xffff0000L) << 16) |
jaroslav@67: ((i >>> 16) & 0xffff0000L) | (i >>> 48);
jaroslav@67: return i;
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns the signum function of the specified {@code long} value. (The
jaroslav@67: * return value is -1 if the specified value is negative; 0 if the
jaroslav@67: * specified value is zero; and 1 if the specified value is positive.)
jaroslav@67: *
jaroslav@67: * @return the signum function of the specified {@code long} value.
jaroslav@67: * @since 1.5
jaroslav@67: */
jaroslav@67: public static int signum(long i) {
jaroslav@67: // HD, Section 2-7
jaroslav@67: return (int) ((i >> 63) | (-i >>> 63));
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns the value obtained by reversing the order of the bytes in the
jaroslav@67: * two's complement representation of the specified {@code long} value.
jaroslav@67: *
jaroslav@67: * @return the value obtained by reversing the bytes in the specified
jaroslav@67: * {@code long} value.
jaroslav@67: * @since 1.5
jaroslav@67: */
jaroslav@67: public static long reverseBytes(long i) {
jaroslav@67: i = (i & 0x00ff00ff00ff00ffL) << 8 | (i >>> 8) & 0x00ff00ff00ff00ffL;
jaroslav@67: return (i << 48) | ((i & 0xffff0000L) << 16) |
jaroslav@67: ((i >>> 16) & 0xffff0000L) | (i >>> 48);
jaroslav@67: }
jaroslav@67:
jaroslav@67: /** use serialVersionUID from JDK 1.0.2 for interoperability */
jaroslav@67: private static final long serialVersionUID = 4290774380558885855L;
jaroslav@67: }
'\u002d'
). If the first argument is not
jaroslav@67: * negative, no sign character appears in the result.
jaroslav@67: *
jaroslav@67: * '\u0030'
); otherwise, the first character of
jaroslav@67: * the representation of the magnitude will not be the zero
jaroslav@67: * character. The following ASCII characters are used as digits:
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * {@code 0123456789abcdefghijklmnopqrstuvwxyz}
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * These are '\u0030'
through
jaroslav@67: * '\u0039'
and '\u0061'
through
jaroslav@67: * '\u007a'
. If {@code radix} is
jaroslav@67: * N, then the first N of these characters
jaroslav@67: * are used as radix-N digits in the order shown. Thus,
jaroslav@67: * the digits for hexadecimal (radix 16) are
jaroslav@67: * {@code 0123456789abcdef}. If uppercase letters are
jaroslav@67: * desired, the {@link java.lang.String#toUpperCase()} method may
jaroslav@67: * be called on the result:
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * {@code Long.toString(n, 16).toUpperCase()}
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * @param i a {@code long} to be converted to a string.
jaroslav@67: * @param radix the radix to use in the string representation.
jaroslav@67: * @return a string representation of the argument in the specified radix.
jaroslav@67: * @see java.lang.Character#MAX_RADIX
jaroslav@67: * @see java.lang.Character#MIN_RADIX
jaroslav@67: */
jaroslav@67: public static String toString(long i, int radix) {
jaroslav@67: if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX)
jaroslav@67: radix = 10;
jaroslav@67: if (radix == 10)
jaroslav@67: return toString(i);
jaroslav@67: char[] buf = new char[65];
jaroslav@67: int charPos = 64;
jaroslav@67: boolean negative = (i < 0);
jaroslav@67:
jaroslav@67: if (!negative) {
jaroslav@67: i = -i;
jaroslav@67: }
jaroslav@67:
jaroslav@67: while (i <= -radix) {
jaroslav@67: buf[charPos--] = Integer.digits[(int)(-(i % radix))];
jaroslav@67: i = i / radix;
jaroslav@67: }
jaroslav@67: buf[charPos] = Integer.digits[(int)(-i)];
jaroslav@67:
jaroslav@67: if (negative) {
jaroslav@67: buf[--charPos] = '-';
jaroslav@67: }
jaroslav@67:
jaroslav@67: return new String(buf, charPos, (65 - charPos));
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns a string representation of the {@code long}
jaroslav@67: * argument as an unsigned integer in base 16.
jaroslav@67: *
jaroslav@67: * '\u0030'
); otherwise, the first character of
jaroslav@67: * the representation of the unsigned magnitude will not be the
jaroslav@67: * zero character. The following characters are used as
jaroslav@67: * hexadecimal digits:
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * {@code 0123456789abcdef}
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * These are the characters '\u0030'
through
jaroslav@67: * '\u0039'
and '\u0061'
through
jaroslav@67: * '\u0066'
. If uppercase letters are desired,
jaroslav@67: * the {@link java.lang.String#toUpperCase()} method may be called
jaroslav@67: * on the result:
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * {@code Long.toHexString(n).toUpperCase()}
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * @param i a {@code long} to be converted to a string.
jaroslav@67: * @return the string representation of the unsigned {@code long}
jaroslav@67: * value represented by the argument in hexadecimal
jaroslav@67: * (base 16).
jaroslav@67: * @since JDK 1.0.2
jaroslav@67: */
jaroslav@67: public static String toHexString(long i) {
jaroslav@67: return toUnsignedString(i, 4);
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns a string representation of the {@code long}
jaroslav@67: * argument as an unsigned integer in base 8.
jaroslav@67: *
jaroslav@67: * '\u0030'
); otherwise, the first character of
jaroslav@67: * the representation of the unsigned magnitude will not be the
jaroslav@67: * zero character. The following characters are used as octal
jaroslav@67: * digits:
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * {@code 01234567}
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * These are the characters '\u0030'
through
jaroslav@67: * '\u0037'
.
jaroslav@67: *
jaroslav@67: * @param i a {@code long} to be converted to a string.
jaroslav@67: * @return the string representation of the unsigned {@code long}
jaroslav@67: * value represented by the argument in octal (base 8).
jaroslav@67: * @since JDK 1.0.2
jaroslav@67: */
jaroslav@67: public static String toOctalString(long i) {
jaroslav@67: return toUnsignedString(i, 3);
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns a string representation of the {@code long}
jaroslav@67: * argument as an unsigned integer in base 2.
jaroslav@67: *
jaroslav@67: * '\u0030'
); otherwise, the first character of
jaroslav@67: * the representation of the unsigned magnitude will not be the
jaroslav@67: * zero character. The characters {@code '0'}
jaroslav@67: * ('\u0030'
) and {@code '1'}
jaroslav@67: * ('\u0031'
) are used as binary digits.
jaroslav@67: *
jaroslav@67: * @param i a {@code long} to be converted to a string.
jaroslav@67: * @return the string representation of the unsigned {@code long}
jaroslav@67: * value represented by the argument in binary (base 2).
jaroslav@67: * @since JDK 1.0.2
jaroslav@67: */
jaroslav@67: public static String toBinaryString(long i) {
jaroslav@67: return toUnsignedString(i, 1);
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Convert the integer to an unsigned number.
jaroslav@67: */
jaroslav@67: private static String toUnsignedString(long i, int shift) {
jaroslav@67: char[] buf = new char[64];
jaroslav@67: int charPos = 64;
jaroslav@67: int radix = 1 << shift;
jaroslav@67: long mask = radix - 1;
jaroslav@67: do {
jaroslav@67: buf[--charPos] = Integer.digits[(int)(i & mask)];
jaroslav@67: i >>>= shift;
jaroslav@67: } while (i != 0);
jaroslav@67: return new String(buf, charPos, (64 - charPos));
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns a {@code String} object representing the specified
jaroslav@67: * {@code long}. The argument is converted to signed decimal
jaroslav@67: * representation and returned as a string, exactly as if the
jaroslav@67: * argument and the radix 10 were given as arguments to the {@link
jaroslav@67: * #toString(long, int)} method.
jaroslav@67: *
jaroslav@67: * @param i a {@code long} to be converted.
jaroslav@67: * @return a string representation of the argument in base 10.
jaroslav@67: */
jaroslav@179: @JavaScriptBody(args = "i", body = "return i.toString();")
jaroslav@67: public static String toString(long i) {
jaroslav@67: if (i == Long.MIN_VALUE)
jaroslav@67: return "-9223372036854775808";
jaroslav@67: int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i);
jaroslav@67: char[] buf = new char[size];
jaroslav@67: getChars(i, size, buf);
jaroslav@179: return new String(buf, 0, size);
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Places characters representing the integer i into the
jaroslav@67: * character array buf. The characters are placed into
jaroslav@67: * the buffer backwards starting with the least significant
jaroslav@67: * digit at the specified index (exclusive), and working
jaroslav@67: * backwards from there.
jaroslav@67: *
jaroslav@67: * Will fail if i == Long.MIN_VALUE
jaroslav@67: */
jaroslav@67: static void getChars(long i, int index, char[] buf) {
jaroslav@67: long q;
jaroslav@67: int r;
jaroslav@67: int charPos = index;
jaroslav@67: char sign = 0;
jaroslav@67:
jaroslav@67: if (i < 0) {
jaroslav@67: sign = '-';
jaroslav@67: i = -i;
jaroslav@67: }
jaroslav@67:
jaroslav@67: // Get 2 digits/iteration using longs until quotient fits into an int
jaroslav@67: while (i > Integer.MAX_VALUE) {
jaroslav@67: q = i / 100;
jaroslav@67: // really: r = i - (q * 100);
jaroslav@67: r = (int)(i - ((q << 6) + (q << 5) + (q << 2)));
jaroslav@67: i = q;
jaroslav@67: buf[--charPos] = Integer.DigitOnes[r];
jaroslav@67: buf[--charPos] = Integer.DigitTens[r];
jaroslav@67: }
jaroslav@67:
jaroslav@67: // Get 2 digits/iteration using ints
jaroslav@67: int q2;
jaroslav@67: int i2 = (int)i;
jaroslav@67: while (i2 >= 65536) {
jaroslav@67: q2 = i2 / 100;
jaroslav@67: // really: r = i2 - (q * 100);
jaroslav@67: r = i2 - ((q2 << 6) + (q2 << 5) + (q2 << 2));
jaroslav@67: i2 = q2;
jaroslav@67: buf[--charPos] = Integer.DigitOnes[r];
jaroslav@67: buf[--charPos] = Integer.DigitTens[r];
jaroslav@67: }
jaroslav@67:
jaroslav@67: // Fall thru to fast mode for smaller numbers
jaroslav@67: // assert(i2 <= 65536, i2);
jaroslav@67: for (;;) {
jaroslav@67: q2 = (i2 * 52429) >>> (16+3);
jaroslav@67: r = i2 - ((q2 << 3) + (q2 << 1)); // r = i2-(q2*10) ...
jaroslav@67: buf[--charPos] = Integer.digits[r];
jaroslav@67: i2 = q2;
jaroslav@67: if (i2 == 0) break;
jaroslav@67: }
jaroslav@67: if (sign != 0) {
jaroslav@67: buf[--charPos] = sign;
jaroslav@67: }
jaroslav@67: }
jaroslav@67:
jaroslav@67: // Requires positive x
jaroslav@67: static int stringSize(long x) {
jaroslav@67: long p = 10;
jaroslav@67: for (int i=1; i<19; i++) {
jaroslav@67: if (x < p)
jaroslav@67: return i;
jaroslav@67: p = 10*p;
jaroslav@67: }
jaroslav@67: return 19;
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Parses the string argument as a signed {@code long} in the
jaroslav@67: * radix specified by the second argument. The characters in the
jaroslav@67: * string must all be digits of the specified radix (as determined
jaroslav@67: * by whether {@link java.lang.Character#digit(char, int)} returns
jaroslav@67: * a nonnegative value), except that the first character may be an
jaroslav@67: * ASCII minus sign {@code '-'} ('\u002D'
) to
jaroslav@67: * indicate a negative value or an ASCII plus sign {@code '+'}
jaroslav@67: * ('\u002B'
) to indicate a positive value. The
jaroslav@67: * resulting {@code long} value is returned.
jaroslav@67: *
jaroslav@67: * '\u004C'
) nor {@code l}
jaroslav@67: * ('\u006C'
) is permitted to appear at the end
jaroslav@67: * of the string as a type indicator, as would be permitted in
jaroslav@67: * Java programming language source code - except that either
jaroslav@67: * {@code L} or {@code l} may appear as a digit for a
jaroslav@67: * radix greater than 22.
jaroslav@67: *
jaroslav@67: *
jaroslav@67: *
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * '\u002d'
) or plus sign {@code
jaroslav@67: * '+'} ('\u002B'
) provided that the string is
jaroslav@67: * longer than length 1.
jaroslav@67: *
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * @param s the {@code String} containing the
jaroslav@67: * {@code long} representation to be parsed.
jaroslav@67: * @param radix the radix to be used while parsing {@code s}.
jaroslav@67: * @return the {@code long} represented by the string argument in
jaroslav@67: * the specified radix.
jaroslav@67: * @throws NumberFormatException if the string does not contain a
jaroslav@67: * parsable {@code long}.
jaroslav@67: */
jaroslav@67: public static long parseLong(String s, int radix)
jaroslav@67: throws NumberFormatException
jaroslav@67: {
jaroslav@67: if (s == null) {
jaroslav@67: throw new NumberFormatException("null");
jaroslav@67: }
jaroslav@67:
jaroslav@67: if (radix < Character.MIN_RADIX) {
jaroslav@67: throw new NumberFormatException("radix " + radix +
jaroslav@67: " less than Character.MIN_RADIX");
jaroslav@67: }
jaroslav@67: if (radix > Character.MAX_RADIX) {
jaroslav@67: throw new NumberFormatException("radix " + radix +
jaroslav@67: " greater than Character.MAX_RADIX");
jaroslav@67: }
jaroslav@67:
jaroslav@67: long result = 0;
jaroslav@67: boolean negative = false;
jaroslav@67: int i = 0, len = s.length();
jaroslav@67: long limit = -Long.MAX_VALUE;
jaroslav@67: long multmin;
jaroslav@67: int digit;
jaroslav@67:
jaroslav@67: if (len > 0) {
jaroslav@67: char firstChar = s.charAt(0);
jaroslav@67: if (firstChar < '0') { // Possible leading "+" or "-"
jaroslav@67: if (firstChar == '-') {
jaroslav@67: negative = true;
jaroslav@67: limit = Long.MIN_VALUE;
jaroslav@67: } else if (firstChar != '+')
jaroslav@67: throw NumberFormatException.forInputString(s);
jaroslav@67:
jaroslav@67: if (len == 1) // Cannot have lone "+" or "-"
jaroslav@67: throw NumberFormatException.forInputString(s);
jaroslav@67: i++;
jaroslav@67: }
jaroslav@67: multmin = limit / radix;
jaroslav@67: while (i < len) {
jaroslav@67: // Accumulating negatively avoids surprises near MAX_VALUE
jaroslav@67: digit = Character.digit(s.charAt(i++),radix);
jaroslav@67: if (digit < 0) {
jaroslav@67: throw NumberFormatException.forInputString(s);
jaroslav@67: }
jaroslav@67: if (result < multmin) {
jaroslav@67: throw NumberFormatException.forInputString(s);
jaroslav@67: }
jaroslav@67: result *= radix;
jaroslav@67: if (result < limit + digit) {
jaroslav@67: throw NumberFormatException.forInputString(s);
jaroslav@67: }
jaroslav@67: result -= digit;
jaroslav@67: }
jaroslav@67: } else {
jaroslav@67: throw NumberFormatException.forInputString(s);
jaroslav@67: }
jaroslav@67: return negative ? result : -result;
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Parses the string argument as a signed decimal {@code long}.
jaroslav@67: * The characters in the string must all be decimal digits, except
jaroslav@67: * that the first character may be an ASCII minus sign {@code '-'}
jaroslav@67: * (
jaroslav@67: * parseLong("0", 10) returns 0L
jaroslav@67: * parseLong("473", 10) returns 473L
jaroslav@67: * parseLong("+42", 10) returns 42L
jaroslav@67: * parseLong("-0", 10) returns 0L
jaroslav@67: * parseLong("-FF", 16) returns -255L
jaroslav@67: * parseLong("1100110", 2) returns 102L
jaroslav@67: * parseLong("99", 8) throws a NumberFormatException
jaroslav@67: * parseLong("Hazelnut", 10) throws a NumberFormatException
jaroslav@67: * parseLong("Hazelnut", 36) returns 1356099454469L
jaroslav@67: *
\u002D'
) to indicate a negative value or an
jaroslav@67: * ASCII plus sign {@code '+'} ('\u002B'
) to
jaroslav@67: * indicate a positive value. The resulting {@code long} value is
jaroslav@67: * returned, exactly as if the argument and the radix {@code 10}
jaroslav@67: * were given as arguments to the {@link
jaroslav@67: * #parseLong(java.lang.String, int)} method.
jaroslav@67: *
jaroslav@67: * '\u004C'
) nor {@code l}
jaroslav@67: * ('\u006C'
) is permitted to appear at the end
jaroslav@67: * of the string as a type indicator, as would be permitted in
jaroslav@67: * Java programming language source code.
jaroslav@67: *
jaroslav@67: * @param s a {@code String} containing the {@code long}
jaroslav@67: * representation to be parsed
jaroslav@67: * @return the {@code long} represented by the argument in
jaroslav@67: * decimal.
jaroslav@67: * @throws NumberFormatException if the string does not contain a
jaroslav@67: * parsable {@code long}.
jaroslav@67: */
jaroslav@67: public static long parseLong(String s) throws NumberFormatException {
jaroslav@67: return parseLong(s, 10);
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns a {@code Long} object holding the value
jaroslav@67: * extracted from the specified {@code String} when parsed
jaroslav@67: * with the radix given by the second argument. The first
jaroslav@67: * argument is interpreted as representing a signed
jaroslav@67: * {@code long} in the radix specified by the second
jaroslav@67: * argument, exactly as if the arguments were given to the {@link
jaroslav@67: * #parseLong(java.lang.String, int)} method. The result is a
jaroslav@67: * {@code Long} object that represents the {@code long}
jaroslav@67: * value specified by the string.
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * {@code new Long(Long.parseLong(s, radix))}
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * @param s the string to be parsed
jaroslav@67: * @param radix the radix to be used in interpreting {@code s}
jaroslav@67: * @return a {@code Long} object holding the value
jaroslav@67: * represented by the string argument in the specified
jaroslav@67: * radix.
jaroslav@67: * @throws NumberFormatException If the {@code String} does not
jaroslav@67: * contain a parsable {@code long}.
jaroslav@67: */
jaroslav@67: public static Long valueOf(String s, int radix) throws NumberFormatException {
jaroslav@67: return Long.valueOf(parseLong(s, radix));
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns a {@code Long} object holding the value
jaroslav@67: * of the specified {@code String}. The argument is
jaroslav@67: * interpreted as representing a signed decimal {@code long},
jaroslav@67: * exactly as if the argument were given to the {@link
jaroslav@67: * #parseLong(java.lang.String)} method. The result is a
jaroslav@67: * {@code Long} object that represents the integer value
jaroslav@67: * specified by the string.
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * {@code new Long(Long.parseLong(s))}
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * @param s the string to be parsed.
jaroslav@67: * @return a {@code Long} object holding the value
jaroslav@67: * represented by the string argument.
jaroslav@67: * @throws NumberFormatException If the string cannot be parsed
jaroslav@67: * as a {@code long}.
jaroslav@67: */
jaroslav@67: public static Long valueOf(String s) throws NumberFormatException
jaroslav@67: {
jaroslav@67: return Long.valueOf(parseLong(s, 10));
jaroslav@67: }
jaroslav@67:
jaroslav@67: private static class LongCache {
jaroslav@67: private LongCache(){}
jaroslav@67:
jaroslav@67: static final Long cache[] = new Long[-(-128) + 127 + 1];
jaroslav@67:
jaroslav@67: static {
jaroslav@67: for(int i = 0; i < cache.length; i++)
jaroslav@67: cache[i] = new Long(i - 128);
jaroslav@67: }
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns a {@code Long} instance representing the specified
jaroslav@67: * {@code long} value.
jaroslav@67: * If a new {@code Long} instance is not required, this method
jaroslav@67: * should generally be used in preference to the constructor
jaroslav@67: * {@link #Long(long)}, as this method is likely to yield
jaroslav@67: * significantly better space and time performance by caching
jaroslav@67: * frequently requested values.
jaroslav@67: *
jaroslav@67: * Note that unlike the {@linkplain Integer#valueOf(int)
jaroslav@67: * corresponding method} in the {@code Integer} class, this method
jaroslav@67: * is not required to cache values within a particular
jaroslav@67: * range.
jaroslav@67: *
jaroslav@67: * @param l a long value.
jaroslav@67: * @return a {@code Long} instance representing {@code l}.
jaroslav@67: * @since 1.5
jaroslav@67: */
jaroslav@67: public static Long valueOf(long l) {
jaroslav@67: final int offset = 128;
jaroslav@67: if (l >= -128 && l <= 127) { // will cache
jaroslav@67: return LongCache.cache[(int)l + offset];
jaroslav@67: }
jaroslav@67: return new Long(l);
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Decodes a {@code String} into a {@code Long}.
jaroslav@67: * Accepts decimal, hexadecimal, and octal numbers given by the
jaroslav@67: * following grammar:
jaroslav@67: *
jaroslav@67: *
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * DecimalNumeral, HexDigits, and OctalDigits
jaroslav@67: * are as defined in section 3.10.1 of
jaroslav@67: * The Java™ Language Specification,
jaroslav@67: * except that underscores are not accepted between digits.
jaroslav@67: *
jaroslav@67: *
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * {@code (int)(this.longValue()^(this.longValue()>>>32))}
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * @return a hash code value for this object.
jaroslav@67: */
jaroslav@67: public int hashCode() {
jaroslav@67: return (int)(value ^ (value >>> 32));
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Compares this object to the specified object. The result is
jaroslav@67: * {@code true} if and only if the argument is not
jaroslav@67: * {@code null} and is a {@code Long} object that
jaroslav@67: * contains the same {@code long} value as this object.
jaroslav@67: *
jaroslav@67: * @param obj the object to compare with.
jaroslav@67: * @return {@code true} if the objects are the same;
jaroslav@67: * {@code false} otherwise.
jaroslav@67: */
jaroslav@67: public boolean equals(Object obj) {
jaroslav@67: if (obj instanceof Long) {
jaroslav@67: return value == ((Long)obj).longValue();
jaroslav@67: }
jaroslav@67: return false;
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Determines the {@code long} value of the system property
jaroslav@67: * with the specified name.
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * {@code getLong(nm, null)}
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * @param nm property name.
jaroslav@67: * @return the {@code Long} value of the property.
jaroslav@67: * @see java.lang.System#getProperty(java.lang.String)
jaroslav@67: * @see java.lang.System#getProperty(java.lang.String, java.lang.String)
jaroslav@67: */
jaroslav@67: public static Long getLong(String nm) {
jaroslav@67: return getLong(nm, null);
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Determines the {@code long} value of the system property
jaroslav@67: * with the specified name.
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * {@code getLong(nm, new Long(val))}
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * but in practice it may be implemented in a manner such as:
jaroslav@67: *
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * to avoid the unnecessary allocation of a {@code Long} object when
jaroslav@67: * the default value is not needed.
jaroslav@67: *
jaroslav@67: * @param nm property name.
jaroslav@67: * @param val default value.
jaroslav@67: * @return the {@code Long} value of the property.
jaroslav@67: * @see java.lang.System#getProperty(java.lang.String)
jaroslav@67: * @see java.lang.System#getProperty(java.lang.String, java.lang.String)
jaroslav@67: */
jaroslav@67: public static Long getLong(String nm, long val) {
jaroslav@67: Long result = Long.getLong(nm, null);
jaroslav@67: return (result == null) ? Long.valueOf(val) : result;
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns the {@code long} value of the system property with
jaroslav@67: * the specified name. The first argument is treated as the name
jaroslav@67: * of a system property. System properties are accessible through
jaroslav@67: * the {@link java.lang.System#getProperty(java.lang.String)}
jaroslav@67: * method. The string value of this property is then interpreted
jaroslav@67: * as a {@code long} value, as per the
jaroslav@67: * {@code Long.decode} method, and a {@code Long} object
jaroslav@67: * representing this value is returned.
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * Long result = getLong(nm, null);
jaroslav@67: * return (result == null) ? new Long(val) : result;
jaroslav@67: *
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * '\u004C'
) nor {@code l}
jaroslav@67: * ('\u006C'
) is permitted to appear at the end
jaroslav@67: * of the property value as a type indicator, as would be
jaroslav@67: * permitted in Java programming language source code.
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * Long.valueOf(x).compareTo(Long.valueOf(y))
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * @param x the first {@code long} to compare
jaroslav@67: * @param y the second {@code long} to compare
jaroslav@67: * @return the value {@code 0} if {@code x == y};
jaroslav@67: * a value less than {@code 0} if {@code x < y}; and
jaroslav@67: * a value greater than {@code 0} if {@code x > y}
jaroslav@67: * @since 1.7
jaroslav@67: */
jaroslav@67: public static int compare(long x, long y) {
jaroslav@67: return (x < y) ? -1 : ((x == y) ? 0 : 1);
jaroslav@67: }
jaroslav@67:
jaroslav@67:
jaroslav@67: // Bit Twiddling
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * The number of bits used to represent a {@code long} value in two's
jaroslav@67: * complement binary form.
jaroslav@67: *
jaroslav@67: * @since 1.5
jaroslav@67: */
jaroslav@67: public static final int SIZE = 64;
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns a {@code long} value with at most a single one-bit, in the
jaroslav@67: * position of the highest-order ("leftmost") one-bit in the specified
jaroslav@67: * {@code long} value. Returns zero if the specified value has no
jaroslav@67: * one-bits in its two's complement binary representation, that is, if it
jaroslav@67: * is equal to zero.
jaroslav@67: *
jaroslav@67: * @return a {@code long} value with a single one-bit, in the position
jaroslav@67: * of the highest-order one-bit in the specified value, or zero if
jaroslav@67: * the specified value is itself equal to zero.
jaroslav@67: * @since 1.5
jaroslav@67: */
jaroslav@67: public static long highestOneBit(long i) {
jaroslav@67: // HD, Figure 3-1
jaroslav@67: i |= (i >> 1);
jaroslav@67: i |= (i >> 2);
jaroslav@67: i |= (i >> 4);
jaroslav@67: i |= (i >> 8);
jaroslav@67: i |= (i >> 16);
jaroslav@67: i |= (i >> 32);
jaroslav@67: return i - (i >>> 1);
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns a {@code long} value with at most a single one-bit, in the
jaroslav@67: * position of the lowest-order ("rightmost") one-bit in the specified
jaroslav@67: * {@code long} value. Returns zero if the specified value has no
jaroslav@67: * one-bits in its two's complement binary representation, that is, if it
jaroslav@67: * is equal to zero.
jaroslav@67: *
jaroslav@67: * @return a {@code long} value with a single one-bit, in the position
jaroslav@67: * of the lowest-order one-bit in the specified value, or zero if
jaroslav@67: * the specified value is itself equal to zero.
jaroslav@67: * @since 1.5
jaroslav@67: */
jaroslav@67: public static long lowestOneBit(long i) {
jaroslav@67: // HD, Section 2-1
jaroslav@67: return i & -i;
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns the number of zero bits preceding the highest-order
jaroslav@67: * ("leftmost") one-bit in the two's complement binary representation
jaroslav@67: * of the specified {@code long} value. Returns 64 if the
jaroslav@67: * specified value has no one-bits in its two's complement representation,
jaroslav@67: * in other words if it is equal to zero.
jaroslav@67: *
jaroslav@67: *
jaroslav@67: *
jaroslav@67: *
jaroslav@67: * @return the number of zero bits preceding the highest-order
jaroslav@67: * ("leftmost") one-bit in the two's complement binary representation
jaroslav@67: * of the specified {@code long} value, or 64 if the value
jaroslav@67: * is equal to zero.
jaroslav@67: * @since 1.5
jaroslav@67: */
jaroslav@67: public static int numberOfLeadingZeros(long i) {
jaroslav@67: // HD, Figure 5-6
jaroslav@67: if (i == 0)
jaroslav@67: return 64;
jaroslav@67: int n = 1;
jaroslav@67: int x = (int)(i >>> 32);
jaroslav@67: if (x == 0) { n += 32; x = (int)i; }
jaroslav@67: if (x >>> 16 == 0) { n += 16; x <<= 16; }
jaroslav@67: if (x >>> 24 == 0) { n += 8; x <<= 8; }
jaroslav@67: if (x >>> 28 == 0) { n += 4; x <<= 4; }
jaroslav@67: if (x >>> 30 == 0) { n += 2; x <<= 2; }
jaroslav@67: n -= x >>> 31;
jaroslav@67: return n;
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns the number of zero bits following the lowest-order ("rightmost")
jaroslav@67: * one-bit in the two's complement binary representation of the specified
jaroslav@67: * {@code long} value. Returns 64 if the specified value has no
jaroslav@67: * one-bits in its two's complement representation, in other words if it is
jaroslav@67: * equal to zero.
jaroslav@67: *
jaroslav@67: * @return the number of zero bits following the lowest-order ("rightmost")
jaroslav@67: * one-bit in the two's complement binary representation of the
jaroslav@67: * specified {@code long} value, or 64 if the value is equal
jaroslav@67: * to zero.
jaroslav@67: * @since 1.5
jaroslav@67: */
jaroslav@67: public static int numberOfTrailingZeros(long i) {
jaroslav@67: // HD, Figure 5-14
jaroslav@67: int x, y;
jaroslav@67: if (i == 0) return 64;
jaroslav@67: int n = 63;
jaroslav@67: y = (int)i; if (y != 0) { n = n -32; x = y; } else x = (int)(i>>>32);
jaroslav@67: y = x <<16; if (y != 0) { n = n -16; x = y; }
jaroslav@67: y = x << 8; if (y != 0) { n = n - 8; x = y; }
jaroslav@67: y = x << 4; if (y != 0) { n = n - 4; x = y; }
jaroslav@67: y = x << 2; if (y != 0) { n = n - 2; x = y; }
jaroslav@67: return n - ((x << 1) >>> 31);
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns the number of one-bits in the two's complement binary
jaroslav@67: * representation of the specified {@code long} value. This function is
jaroslav@67: * sometimes referred to as the population count.
jaroslav@67: *
jaroslav@67: * @return the number of one-bits in the two's complement binary
jaroslav@67: * representation of the specified {@code long} value.
jaroslav@67: * @since 1.5
jaroslav@67: */
jaroslav@67: public static int bitCount(long i) {
jaroslav@67: // HD, Figure 5-14
jaroslav@67: i = i - ((i >>> 1) & 0x5555555555555555L);
jaroslav@67: i = (i & 0x3333333333333333L) + ((i >>> 2) & 0x3333333333333333L);
jaroslav@67: i = (i + (i >>> 4)) & 0x0f0f0f0f0f0f0f0fL;
jaroslav@67: i = i + (i >>> 8);
jaroslav@67: i = i + (i >>> 16);
jaroslav@67: i = i + (i >>> 32);
jaroslav@67: return (int)i & 0x7f;
jaroslav@67: }
jaroslav@67:
jaroslav@67: /**
jaroslav@67: * Returns the value obtained by rotating the two's complement binary
jaroslav@67: * representation of the specified {@code long} value left by the
jaroslav@67: * specified number of bits. (Bits shifted out of the left hand, or
jaroslav@67: * high-order, side reenter on the right, or low-order.)
jaroslav@67: *
jaroslav@67: *