1 /*

     2  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  *

    23  */

    24 

    25 package sun.jvm.hotspot.gc.z;

    26 

    27 import sun.jvm.hotspot.debugger.Address;

    28 

    29 class ZForwardingTableEntry {

    30     private Address entry;

    31 

    32     ZForwardingTableEntry(Address addr) {

    33         entry = addr;

    34     }

    35 

    36     private static long empty() {

    37         return ~0L;

    38     }

    39 

    40     boolean is_empty() {

    41         return entry.asLongValue() == empty();

    42     }

    43 

    44     Address to_offset() {

    45         return entry.andWithMask((1L << 42) - 1);

    46     }

    47 

    48     long from_index() {

    49         return entry.asLongValue() >>> 42;

    50     }

    51 

    52     public String toString() {

    53         return entry + " - from_index: " + from_index() + " to_offset: " + to_offset();

    54     }

    55 }