OopMapValue.java revision 9883:903a2e023ffb 
1/*
2 * Copyright (c) 2000, 2008, 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.
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23 */
24
25package sun.jvm.hotspot.compiler;
26
27import java.util.*;
28
29import sun.jvm.hotspot.code.*;
30import sun.jvm.hotspot.runtime.*;
31import sun.jvm.hotspot.types.*;
32import sun.jvm.hotspot.utilities.*;
33
34public class OopMapValue {
35  private short value;
36  private short contentReg;
37
38  /** Read from target VM; located in compiler/oopMap.hpp */
39  // How bits are organized
40  static int TYPE_BITS;
41  static int REGISTER_BITS;
42  static int TYPE_SHIFT;
43  static int REGISTER_SHIFT;
44  static int TYPE_MASK;
45  static int TYPE_MASK_IN_PLACE;
46  static int REGISTER_MASK;
47  static int REGISTER_MASK_IN_PLACE;
48
49  // Types of OopValues
50  static int UNUSED_VALUE;
51  static int OOP_VALUE;
52  static int NARROWOOP_VALUE;
53  static int CALLEE_SAVED_VALUE;
54  static int DERIVED_OOP_VALUE;
55
56  static {
57    VM.registerVMInitializedObserver(new Observer() {
58        public void update(Observable o, Object data) {
59          initialize(VM.getVM().getTypeDataBase());
60        }
61      });
62  }
63
64  private static void initialize(TypeDataBase db) {
65    TYPE_BITS              = db.lookupIntConstant("OopMapValue::type_bits").intValue();
66    REGISTER_BITS          = db.lookupIntConstant("OopMapValue::register_bits").intValue();
67    TYPE_SHIFT             = db.lookupIntConstant("OopMapValue::type_shift").intValue();
68    REGISTER_SHIFT         = db.lookupIntConstant("OopMapValue::register_shift").intValue();
69    TYPE_MASK              = db.lookupIntConstant("OopMapValue::type_mask").intValue();
70    TYPE_MASK_IN_PLACE     = db.lookupIntConstant("OopMapValue::type_mask_in_place").intValue();
71    REGISTER_MASK          = db.lookupIntConstant("OopMapValue::register_mask").intValue();
72    REGISTER_MASK_IN_PLACE = db.lookupIntConstant("OopMapValue::register_mask_in_place").intValue();
73    UNUSED_VALUE           = db.lookupIntConstant("OopMapValue::unused_value").intValue();
74    OOP_VALUE              = db.lookupIntConstant("OopMapValue::oop_value").intValue();
75    NARROWOOP_VALUE        = db.lookupIntConstant("OopMapValue::narrowoop_value").intValue();
76    CALLEE_SAVED_VALUE     = db.lookupIntConstant("OopMapValue::callee_saved_value").intValue();
77    DERIVED_OOP_VALUE      = db.lookupIntConstant("OopMapValue::derived_oop_value").intValue();
78  }
79
80  public static abstract class OopTypes {
81    public static final OopTypes UNUSED_VALUE       = new OopTypes() { int getValue() { return OopMapValue.UNUSED_VALUE;       }};
82    public static final OopTypes OOP_VALUE          = new OopTypes() { int getValue() { return OopMapValue.OOP_VALUE;          }};
83    public static final OopTypes NARROWOOP_VALUE    = new OopTypes() { int getValue() { return OopMapValue.NARROWOOP_VALUE;         }};
84    public static final OopTypes CALLEE_SAVED_VALUE = new OopTypes() { int getValue() { return OopMapValue.CALLEE_SAVED_VALUE; }};
85    public static final OopTypes DERIVED_OOP_VALUE  = new OopTypes() { int getValue() { return OopMapValue.DERIVED_OOP_VALUE;  }};
86
87    abstract int getValue();
88    protected OopTypes() {}
89  }
90
91  public OopMapValue()                                  { setValue((short) 0); setContentReg(new VMReg(0)); }
92  public OopMapValue(VMReg reg, OopTypes t)             { setReg(reg); setType(t);                      }
93  public OopMapValue(VMReg reg, OopTypes t, VMReg reg2) { setReg(reg); setType(t); setContentReg(reg2); }
94  public OopMapValue(CompressedReadStream stream)       { readFrom(stream);                             }
95
96  public void readFrom(CompressedReadStream stream) {
97    setValue((short) stream.readInt());
98    if (isCalleeSaved() || isDerivedOop()) {
99      setContentReg(new VMReg(stream.readInt()));
100    }
101  }
102
103  // Querying
104  public boolean isOop()         { return (getValue() & TYPE_MASK_IN_PLACE) == OOP_VALUE;          }
105  public boolean isNarrowOop()   { return (getValue() & TYPE_MASK_IN_PLACE) == NARROWOOP_VALUE;    }
106  public boolean isCalleeSaved() { return (getValue() & TYPE_MASK_IN_PLACE) == CALLEE_SAVED_VALUE; }
107  public boolean isDerivedOop()  { return (getValue() & TYPE_MASK_IN_PLACE) == DERIVED_OOP_VALUE;  }
108
109  public VMReg getReg() { return new VMReg((getValue() & REGISTER_MASK_IN_PLACE) >> REGISTER_SHIFT); }
110  public void  setReg(VMReg r) { setValue((short) (r.getValue() << REGISTER_SHIFT | (getValue() & TYPE_MASK_IN_PLACE))); }
111
112  public OopTypes getType() {
113    int which = (getValue() & TYPE_MASK_IN_PLACE);
114         if (which == UNUSED_VALUE) return OopTypes.UNUSED_VALUE;
115    else if (which == OOP_VALUE)    return OopTypes.OOP_VALUE;
116    else if (which == NARROWOOP_VALUE)   return OopTypes.NARROWOOP_VALUE;
117    else if (which == CALLEE_SAVED_VALUE) return OopTypes.CALLEE_SAVED_VALUE;
118    else if (which == DERIVED_OOP_VALUE)  return OopTypes.DERIVED_OOP_VALUE;
119    else throw new InternalError("unknown which " + which + " (TYPE_MASK_IN_PLACE = " + TYPE_MASK_IN_PLACE + ")");
120  }
121  public void setType(OopTypes t) { setValue((short) ((getValue() & REGISTER_MASK_IN_PLACE) | t.getValue())); }
122
123  public VMReg getContentReg()        { return new VMReg(contentReg); }
124  public void  setContentReg(VMReg r) { contentReg = (short) r.getValue(); }
125
126  /** Physical location queries */
127  public boolean isRegisterLoc()      { return (getReg().lessThan(VM.getVM().getVMRegImplInfo().getStack0())); }
128  public boolean isStackLoc()         { return (getReg().greaterThanOrEqual(VM.getVM().getVMRegImplInfo().getStack0())); }
129
130  /** Returns offset from sp. */
131  public int getStackOffset() {
132    if (Assert.ASSERTS_ENABLED) {
133      Assert.that(isStackLoc(), "must be stack location");
134    }
135    return getReg().minus(VM.getVM().getVMRegImplInfo().getStack0());
136  }
137
138  //--------------------------------------------------------------------------------
139  // Internals only below this point
140  //
141
142  private void setValue(short value) {
143    this.value = value;
144  }
145
146  private int getValue() {
147    return value;
148  }
149}
150