/*

 * Copyright (c) 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.

 *

 * 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

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 */

package sun.jvm.hotspot.gc.z;

import sun.jvm.hotspot.debugger.Address;

import sun.jvm.hotspot.runtime.VM;

class ZUtils {

    private static final long MSB = ~0L ^ (~0L >>> 1);

    private static Address msbAddress() {

        return VM.getVM().getUniverse().heap().start().orWithMask(MSB).andWithMask(MSB);

    }

    static Address longToAddress(long value) {

        // If the value of an Address becomes 0, null is returned instead of an Address.

        // Start with a one-bit address and as a last step, remove that bit.

        Address oneAddress = msbAddress();

        return oneAddress.orWithMask(value).xorWithMask(ZAddress.as_long(oneAddress));

    }

}