1 cananian 1.3.2.10 // Instr.java, created Sun Sep 13 22:49:21 1998 by cananian
2 cananian 1.3 // Copyright (C) 1998 C. Scott Ananian <cananian@alumni.princeton.edu>
3 cananian 1.3 // Licensed under the terms of the GNU GPL; see COPYING for details.
4 cananian 1.1 package harpoon.IR.Bytecode;
5 cananian 1.1
6 cananian 1.3.2.4 import harpoon.ClassFile.HCodeElement;
7 duncan 1.3.2.12 import harpoon.IR.Properties.CFGEdge;
8 duncan 1.3.2.12 import harpoon.IR.Properties.CFGraphable;
9 cananian 1.3.2.1 import harpoon.Util.ArrayFactory;
10 cananian 1.1
11 cananian 1.3.2.5 import java.util.ArrayList;
12 sportbilly 1.3.2.7 import java.util.Arrays;
13 sportbilly 1.3.2.7 import java.util.Collection;
14 cananian 1.3.2.5 import java.util.List;
15 cananian 1.1 /**
16 cananian 1.1 * <code>Bytecode.Instr</code> is the base type for the specific
17 cananian 1.1 * bytecode instruction classes. It provides standard methods
18 cananian 1.1 * for accessing the opcode of a specific instruction and for
19 cananian 1.1 * determining which instructions may preceed or follow it.
20 cananian 1.1 * <p>As with all <code>HCodeElement</code>s, <code>Instr</code>s are
21 cananian 1.1 * traceable to an original source file and line number, and have
22 cananian 1.1 * a unique numeric identifier.
23 cananian 1.1 *
24 cananian 1.1 * @author C. Scott Ananian <cananian@alumni.princeton.edu>
25 cananian 1.9 * @version $Id: Instr.java,v 1.9 2004/02/07 21:28:51 cananian Exp $
26 cananian 1.1 * @see InGen
27 cananian 1.1 * @see InCti
28 cananian 1.1 * @see InMerge
29 cananian 1.1 * @see InSwitch
30 cananian 1.1 * @see Code
31 cananian 1.1 */
32 cananian 1.2 public abstract class Instr
33 cananian 1.6 implements HCodeElement, harpoon.IR.Properties.CFGraphable<Instr,InstrEdge>,
34 cananian 1.6 Comparable<Instr> {
35 cananian 1.4.2.1 final String sourcefile;
36 cananian 1.4.2.1 final int linenumber;
37 cananian 1.4.2.1 final int id;
38 cananian 1.1 /** Constructor. */
39 cananian 1.1 protected Instr(String sourcefile, int linenumber) {
40 cananian 1.1 this.sourcefile = sourcefile;
41 cananian 1.1 this.linenumber = linenumber;
42 cananian 1.3.2.5 /* it would be nice if this were unique for a particular Instr in a
43 cananian 1.3.2.5 * method, instead of depending on the translation order of different
44 cananian 1.3.2.5 * methods, but we'll settle for the total ordering Comparable implies.
45 cananian 1.3.2.5 */
46 cananian 1.1 synchronized(lock) {
47 cananian 1.1 this.id = next_id++;
48 cananian 1.1 }
49 cananian 1.1 }
50 cananian 1.1 static int next_id = 0;
51 cananian 1.1 static final Object lock = new Object();
52 cananian 1.1
53 cananian 1.1 /** Returns the original source file name that this bytecode instruction
54 cananian 1.1 * is derived from. */
55 cananian 1.1 public String getSourceFile() { return sourcefile; }
56 cananian 1.1 /** Returns the line in the original source file that this bytecode
57 cananian 1.1 * instruction can be traced to. */
58 cananian 1.1 public int getLineNumber() { return linenumber; }
59 cananian 1.1 /** Returns a unique numeric identifier for this element. */
60 cananian 1.1 public int getID() { return id; }
61 cananian 1.1 /** Returns the java bytecode of this instruction. */
62 cananian 1.1 public abstract byte getOpcode();
63 cananian 1.3.2.5 /** Natural ordering on <code>Instr</code>s. */
64 cananian 1.6 public int compareTo(Instr o) {
65 cananian 1.3.2.5 /* ordering is by id. */
66 cananian 1.6 return o.id - this.id;
67 cananian 1.3.2.5 }
68 cananian 1.3.2.5 public boolean equals(Object o) { // exploit global uniqueness of id.
69 cananian 1.3.2.8 if (this==o) return true;
70 cananian 1.3.2.8 if (o==null) return false;
71 cananian 1.3.2.8 try { return ((Instr) o).id == this.id; }
72 cananian 1.3.2.8 catch (ClassCastException e) { return false; }
73 cananian 1.3.2.5 }
74 cananian 1.3.2.5 public int hashCode() { return id; } // exploit global uniqueness of id.
75 cananian 1.3.2.1
76 cananian 1.3.2.1 /** Array Factory: makes <code>Instr[]</code>s. */
77 cananian 1.6 public static final ArrayFactory<Instr> arrayFactory =
78 cananian 1.6 new ArrayFactory<Instr>() {
79 cananian 1.6 public Instr[] newArray(int len) { return new Instr[len]; }
80 cananian 1.3.2.1 };
81 cananian 1.1
82 cananian 1.1 /** Return a list of all the <code>Instr</code>s that can precede
83 cananian 1.1 * this one. */
84 cananian 1.1 public Instr[] prev() {
85 cananian 1.6 return prev.toArray(new Instr[prev.size()]);
86 cananian 1.1 }
87 cananian 1.1 /** Return a list of all the possible <code>Instr</code>s that may
88 cananian 1.1 * succeed this one. */
89 cananian 1.1 public Instr[] next() {
90 cananian 1.6 return next.toArray(new Instr[next.size()]);
91 cananian 1.1 }
92 cananian 1.3.2.2 /** Return the specified successor of this <code>Instr</code>. */
93 cananian 1.6 public Instr next(int i) { return next.get(i); }
94 cananian 1.3.2.2 /** Return the specified predecessor of this <code>Instr</code>. */
95 cananian 1.6 public Instr prev(int i) { return prev.get(i); }
96 cananian 1.1
97 cananian 1.1 /** Add a predecessor to this <code>Instr</code>. */
98 cananian 1.3.2.5 void addPrev(Instr prev) { this.prev.add(prev); }
99 cananian 1.1 /** Add a successor to this <code>Instr</code>. */
100 cananian 1.3.2.5 void addNext(Instr next) { this.next.add(next); }
101 cananian 1.1 /** Remove a predecessor from this <code>Instr</code>. */
102 cananian 1.3.2.5 void removePrev(Instr prev) { this.prev.remove(prev); }
103 cananian 1.1 /** Remove a successor from this <code>Instr</code>. */
104 cananian 1.3.2.5 void removeNext(Instr next) { this.next.remove(next); }
105 cananian 1.1
106 cananian 1.1 /** Internal predecessor list. */
107 cananian 1.6 final List<Instr> prev = new ArrayList<Instr>(2);
108 cananian 1.1 /** Internal successor list. */
109 cananian 1.6 final List<Instr> next = new ArrayList<Instr>(2);
110 cananian 1.2
111 cananian 1.3.2.11 // CFGraphable interface:
112 cananian 1.6 public InstrEdge newEdge(Instr from, Instr to) {
113 cananian 1.6 return new InstrEdge(from, to);
114 cananian 1.2 }
115 cananian 1.6 public InstrEdge[] succ() {
116 cananian 1.6 InstrEdge[] r = new InstrEdge[next.size()];
117 cananian 1.2 for (int i=0; i<r.length; i++)
118 cananian 1.6 r[i] = newEdge(this, next.get(i));
119 cananian 1.2 return r;
120 cananian 1.2 }
121 cananian 1.6 public InstrEdge[] pred() {
122 cananian 1.6 InstrEdge[] r = new InstrEdge[prev.size()];
123 cananian 1.2 for (int i=0; i<r.length; i++)
124 cananian 1.6 r[i] = newEdge(prev.get(i), this);
125 cananian 1.2 return r;
126 cananian 1.2 }
127 cananian 1.6 public InstrEdge[] edges() {
128 cananian 1.6 InstrEdge[] n = succ();
129 cananian 1.6 InstrEdge[] p = pred();
130 cananian 1.6 InstrEdge[] r = new InstrEdge[n.length + p.length];
131 cananian 1.2 System.arraycopy(n, 0, r, 0, n.length);
132 cananian 1.2 System.arraycopy(p, 0, r, n.length, p.length);
133 cananian 1.2 return r;
134 cananian 1.2 }
135 cananian 1.9 public List<InstrEdge> edgeC() { return Arrays.asList(edges()); }
136 cananian 1.9 public List<InstrEdge> predC() { return Arrays.asList(pred()); }
137 cananian 1.9 public List<InstrEdge> succC() { return Arrays.asList(succ()); }
138 cananian 1.8 public boolean isSucc(Instr i) { return next.contains(i); }
139 cananian 1.8 public boolean isPred(Instr i) { return prev.contains(i); }
140 cananian 1.6 }
141 cananian 1.6 class InstrEdge extends CFGEdge<Instr,InstrEdge> {
142 cananian 1.6 final Instr from, to;
143 cananian 1.6 InstrEdge(Instr from, Instr to) { this.from = from; this.to = to; }
144 cananian 1.7 public Instr from() { return from; }
145 cananian 1.7 public Instr to() { return to; }
146 cananian 1.6 public boolean equals(Object o) {
147 cananian 1.6 CFGEdge hce;
148 cananian 1.6 if (this==o) return true;
149 cananian 1.6 if (o==null) return false;
150 cananian 1.6 try { hce=(CFGEdge)o; } catch (ClassCastException e) {return false; }
151 cananian 1.6 return hce.from() == from && hce.to() == to;
152 cananian 1.6 }
153 cananian 1.6 public int hashCode() { return from.hashCode() ^ to.hashCode(); }
154 cananian 1.1 }