View Javadoc
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.
22   *
23   */
24  
25  package sun.jvm.hotspot.compiler;
26  
27  import java.util.*;
28  
29  import sun.jvm.hotspot.code.*;
30  import sun.jvm.hotspot.runtime.*;
31  import sun.jvm.hotspot.types.*;
32  import sun.jvm.hotspot.utilities.*;
33  
34  public 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 VALUE_VALUE;
53    static int NARROWOOP_VALUE;
54    static int CALLEE_SAVED_VALUE;
55    static int DERIVED_OOP_VALUE;
56  
57    static {
58      VM.registerVMInitializedObserver(new Observer() {
59          public void update(Observable o, Object data) {
60            initialize(VM.getVM().getTypeDataBase());
61          }
62        });
63    }
64  
65    private static void initialize(TypeDataBase db) {
66      TYPE_BITS              = db.lookupIntConstant("OopMapValue::type_bits").intValue();
67      REGISTER_BITS          = db.lookupIntConstant("OopMapValue::register_bits").intValue();
68      TYPE_SHIFT             = db.lookupIntConstant("OopMapValue::type_shift").intValue();
69      REGISTER_SHIFT         = db.lookupIntConstant("OopMapValue::register_shift").intValue();
70      TYPE_MASK              = db.lookupIntConstant("OopMapValue::type_mask").intValue();
71      TYPE_MASK_IN_PLACE     = db.lookupIntConstant("OopMapValue::type_mask_in_place").intValue();
72      REGISTER_MASK          = db.lookupIntConstant("OopMapValue::register_mask").intValue();
73      REGISTER_MASK_IN_PLACE = db.lookupIntConstant("OopMapValue::register_mask_in_place").intValue();
74      UNUSED_VALUE           = db.lookupIntConstant("OopMapValue::unused_value").intValue();
75      OOP_VALUE              = db.lookupIntConstant("OopMapValue::oop_value").intValue();
76      VALUE_VALUE            = db.lookupIntConstant("OopMapValue::value_value").intValue();
77      NARROWOOP_VALUE        = db.lookupIntConstant("OopMapValue::narrowoop_value").intValue();
78      CALLEE_SAVED_VALUE     = db.lookupIntConstant("OopMapValue::callee_saved_value").intValue();
79      DERIVED_OOP_VALUE      = db.lookupIntConstant("OopMapValue::derived_oop_value").intValue();
80    }
81  
82    public static abstract class OopTypes {
83      public static final OopTypes UNUSED_VALUE       = new OopTypes() { int getValue() { return OopMapValue.UNUSED_VALUE;       }};
84      public static final OopTypes OOP_VALUE          = new OopTypes() { int getValue() { return OopMapValue.OOP_VALUE;          }};
85      public static final OopTypes VALUE_VALUE        = new OopTypes() { int getValue() { return OopMapValue.VALUE_VALUE;        }};
86      public static final OopTypes NARROWOOP_VALUE    = new OopTypes() { int getValue() { return OopMapValue.NARROWOOP_VALUE;         }};
87      public static final OopTypes CALLEE_SAVED_VALUE = new OopTypes() { int getValue() { return OopMapValue.CALLEE_SAVED_VALUE; }};
88      public static final OopTypes DERIVED_OOP_VALUE  = new OopTypes() { int getValue() { return OopMapValue.DERIVED_OOP_VALUE;  }};
89  
90      abstract int getValue();
91      protected OopTypes() {}
92    }
93  
94    public OopMapValue()                                  { setValue((short) 0); setContentReg(new VMReg(0)); }
95    public OopMapValue(VMReg reg, OopTypes t)             { setReg(reg); setType(t);                      }
96    public OopMapValue(VMReg reg, OopTypes t, VMReg reg2) { setReg(reg); setType(t); setContentReg(reg2); }
97    public OopMapValue(CompressedReadStream stream)       { readFrom(stream);                             }
98  
99    public void readFrom(CompressedReadStream stream) {
100     setValue((short) stream.readInt());
101     if (isCalleeSaved() || isDerivedOop()) {
102       setContentReg(new VMReg(stream.readInt()));
103     }
104   }
105 
106   // Querying
107   public boolean isOop()         { return (getValue() & TYPE_MASK_IN_PLACE) == OOP_VALUE;          }
108   public boolean isValue()       { return (getValue() & TYPE_MASK_IN_PLACE) == VALUE_VALUE;        }
109   public boolean isNarrowOop()   { return (getValue() & TYPE_MASK_IN_PLACE) == NARROWOOP_VALUE;    }
110   public boolean isCalleeSaved() { return (getValue() & TYPE_MASK_IN_PLACE) == CALLEE_SAVED_VALUE; }
111   public boolean isDerivedOop()  { return (getValue() & TYPE_MASK_IN_PLACE) == DERIVED_OOP_VALUE;  }
112 
113   public VMReg getReg() { return new VMReg((getValue() & REGISTER_MASK_IN_PLACE) >> REGISTER_SHIFT); }
114   public void  setReg(VMReg r) { setValue((short) (r.getValue() << REGISTER_SHIFT | (getValue() & TYPE_MASK_IN_PLACE))); }
115 
116   public OopTypes getType() {
117     int which = (getValue() & TYPE_MASK_IN_PLACE);
118          if (which == UNUSED_VALUE) return OopTypes.UNUSED_VALUE;
119     else if (which == OOP_VALUE)    return OopTypes.OOP_VALUE;
120     else if (which == VALUE_VALUE)  return OopTypes.VALUE_VALUE;
121     else if (which == NARROWOOP_VALUE)   return OopTypes.NARROWOOP_VALUE;
122     else if (which == CALLEE_SAVED_VALUE) return OopTypes.CALLEE_SAVED_VALUE;
123     else if (which == DERIVED_OOP_VALUE)  return OopTypes.DERIVED_OOP_VALUE;
124     else throw new InternalError("unknown which " + which + " (TYPE_MASK_IN_PLACE = " + TYPE_MASK_IN_PLACE + ")");
125   }
126   public void setType(OopTypes t) { setValue((short) ((getValue() & REGISTER_MASK_IN_PLACE) | t.getValue())); }
127 
128   public VMReg getContentReg()        { return new VMReg(contentReg); }
129   public void  setContentReg(VMReg r) { contentReg = (short) r.getValue(); }
130 
131   /** Physical location queries */
132   public boolean isRegisterLoc()      { return (getReg().lessThan(VM.getVM().getVMRegImplInfo().getStack0())); }
133   public boolean isStackLoc()         { return (getReg().greaterThanOrEqual(VM.getVM().getVMRegImplInfo().getStack0())); }
134 
135   /** Returns offset from sp. */
136   public int getStackOffset() {
137     if (Assert.ASSERTS_ENABLED) {
138       Assert.that(isStackLoc(), "must be stack location");
139     }
140     return getReg().minus(VM.getVM().getVMRegImplInfo().getStack0());
141   }
142 
143   //--------------------------------------------------------------------------------
144   // Internals only below this point
145   //
146 
147   private void setValue(short value) {
148     this.value = value;
149   }
150 
151   private int getValue() {
152     return value;
153   }
154 }