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* Copyright (c) 2001, 2004, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* 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.
*
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package sun.jvm.hotspot.utilities;
Bit manipulation routines /** Bit manipulation routines */
public class Bits {
public static final int AllBits = ~0;
public static final int NoBits = 0;
public static final int OneBit = 1;
public static final int BitsPerByte = 8;
public static final int BitsPerInt = 32;
public static final int LogBytesPerInt = 2;
public static final int LogBytesPerLong = 3;
public static int setBits(int x, int m) {
return x | m;
}
public static int clearBits(int x, int m) {
return x & ~m;
}
public static int nthBit(int n) {
return (n > 32) ? 0 : (OneBit << n);
}
public static int setNthBit(int x, int n) {
return setBits(x, nthBit(n));
}
public static int clearNthBit(int x, int n) {
return clearBits(x, nthBit(n));
}
public static boolean isSetNthBit(int word, int n) {
return maskBits(word, nthBit(n)) != NoBits;
}
public static int rightNBits(int n) {
return (nthBit(n) - 1);
}
public static int maskBits(int x, int m) {
return x & m;
}
public static long maskBitsLong(long x, long m) {
return x & m;
}
Returns integer round-up to the nearest multiple of s (s must be
a power of two) /** Returns integer round-up to the nearest multiple of s (s must be
a power of two) */
public static int roundTo(int x, int s) {
int m = s - 1;
return maskBits(x + m, ~m);
}
}