1 cananian 1.1.2.6 // InstrLABEL.java, created Wed Feb 17 16:32:40 1999 by andyb
2 andyb 1.1.2.1 // Copyright (C) 1999 Andrew Berkheimer <andyb@mit.edu>
3 andyb 1.1.2.1 // Licensed under the terms of the GNU GPL; see COPYING for details.
4 andyb 1.1.2.1 package harpoon.IR.Assem;
5 andyb 1.1.2.1
6 andyb 1.1.2.1 import harpoon.ClassFile.HCodeElement;
7 andyb 1.1.2.1 import harpoon.Temp.Label;
8 cananian 1.1.2.13 import harpoon.Temp.TempMap;
9 cananian 1.6 import net.cscott.jutil.CombineIterator;
10 cananian 1.6 import net.cscott.jutil.Default;
11 cananian 1.6 import net.cscott.jutil.UnmodifiableIterator;
12 pnkfelix 1.1.2.9
13 cananian 1.5 import java.util.AbstractList;
14 cananian 1.5 import java.util.Arrays;
15 cananian 1.5 import java.util.Collection;
16 pnkfelix 1.1.2.9 import java.util.Iterator;
17 cananian 1.5 import java.util.List;
18 pnkfelix 1.1.2.9 import java.util.Set;
19 andyb 1.1.2.1
20 andyb 1.1.2.1 /**
21 andyb 1.1.2.1 * <code>InstrLABEL</code> is used to represents code labels in
22 andyb 1.1.2.1 * assembly-level instruction representations.
23 andyb 1.1.2.1 *
24 andyb 1.1.2.1 * @author Andrew Berkheimer <andyb@mit.edu>
25 cananian 1.6 * @version $Id: InstrLABEL.java,v 1.6 2004/02/08 01:55:08 cananian Exp $
26 andyb 1.1.2.1 */
27 andyb 1.1.2.1 public class InstrLABEL extends Instr {
28 andyb 1.1.2.4 private Label label;
29 andyb 1.1.2.1
30 cananian 1.1.2.5 /** Create a code label <code>Instr</code>. The specified
31 cananian 1.1.2.5 <code>String</code> <code>a</code> should be the
32 cananian 1.1.2.5 assembly-language representation of the given
33 cananian 1.1.2.5 <code>Label</code> <code>l</code>. */
34 andyb 1.1.2.2 public InstrLABEL(InstrFactory inf, HCodeElement src, String a, Label l) {
35 pnkfelix 1.1.2.14 this(inf, src, a, l, true);
36 andyb 1.1.2.1 }
37 pnkfelix 1.1.2.14
38 pnkfelix 1.1.2.14 private InstrLABEL(InstrFactory inf, HCodeElement src,
39 pnkfelix 1.1.2.14 String a, Label l, boolean falls) {
40 pnkfelix 1.1.2.14 super(inf, src, a, null, null, falls, null);
41 pnkfelix 1.1.2.14 label = l;
42 pnkfelix 1.1.2.14 inf.labelToInstrLABELmap.put(l, this);
43 pnkfelix 1.1.2.14 }
44 pnkfelix 1.1.2.14
45 pnkfelix 1.1.2.14 public static InstrLABEL makeNoFall
46 pnkfelix 1.1.2.14 (InstrFactory inf, HCodeElement src, String a, Label l) {
47 pnkfelix 1.1.2.14 return new InstrLABEL(inf, src, a, l, false);
48 pnkfelix 1.1.2.14 }
49 pnkfelix 1.1.2.3
50 cananian 1.1.2.5 /** Return the code label specified in the constructor. */
51 andyb 1.1.2.4 public Label getLabel() { return label; }
52 andyb 1.1.2.4 // should clone label!!!!!!!
53 andyb 1.1.2.4
54 cananian 1.1.2.13 public Instr rename(InstrFactory inf, TempMap defMap, TempMap useMap) {
55 cananian 1.1.2.13 // should clone label or something.
56 cananian 1.1.2.13 return new InstrLABEL(inf, this, getAssem(), label);
57 cananian 1.1.2.13 }
58 pnkfelix 1.1.2.15 public Instr cloneMutateAssem(InstrFactory inf, String newAssem) {
59 pnkfelix 1.1.2.15 return new InstrLABEL(inf, this, newAssem, label);
60 pnkfelix 1.1.2.15 }
61 pnkfelix 1.1.2.15
62 andyb 1.1.2.4 /** Accept a visitor. */
63 pnkfelix 1.1.2.12 public void accept(InstrVisitor v) { v.visit(this); }
64 pnkfelix 1.1.2.8
65 pnkfelix 1.1.2.8 /** Returns true.
66 pnkfelix 1.1.2.8 Labels are designed to have multiple predecessors.
67 pnkfelix 1.1.2.8 */
68 pnkfelix 1.1.2.8 protected boolean hasMultiplePredecessors() {
69 pnkfelix 1.1.2.8 return true;
70 pnkfelix 1.1.2.9 }
71 pnkfelix 1.1.2.9
72 cananian 1.5 public List<InstrEdge> predC() {
73 cananian 1.5 // XXX not entirely happy w/ this. We're taking an O(s.size())
74 cananian 1.5 // performance hit on each call to predC(). But this beats taking
75 cananian 1.5 // the same hit on each call to precC().get().
76 cananian 1.5 Set<Instr> s = getFactory().labelToBranches.get(label);
77 cananian 1.5 final List<Instr> branchesHere =
78 cananian 1.5 Arrays.asList(s.toArray(new Instr[s.size()]));
79 cananian 1.5 return new AbstractList<InstrEdge>() {
80 pnkfelix 1.1.2.9 public int size() {
81 pnkfelix 1.1.2.9 int total=0;
82 pnkfelix 1.1.2.9 if (prev!=null && prev.canFallThrough) {
83 pnkfelix 1.1.2.9 total++;
84 pnkfelix 1.1.2.9 }
85 pnkfelix 1.1.2.9
86 cananian 1.5 total += branchesHere.size();
87 pnkfelix 1.1.2.9
88 pnkfelix 1.1.2.9 return total;
89 pnkfelix 1.1.2.9 }
90 cananian 1.5 public InstrEdge get(int i) {
91 cananian 1.5 // first iterator: prev falls to this?
92 cananian 1.5 if ((prev != null) && prev.canFallThrough) {
93 cananian 1.5 if (i--==0) return new InstrEdge(prev, InstrLABEL.this);
94 cananian 1.5 }
95 cananian 1.5 // second iterator: branches to this?
96 cananian 1.5 // hm. need to index these; using the static branchesHere
97 cananian 1.5 // list may be non-optimal.
98 cananian 1.5 return new InstrEdge(branchesHere.get(i), InstrLABEL.this);
99 pnkfelix 1.1.2.9 }
100 pnkfelix 1.1.2.9 };
101 pnkfelix 1.1.2.8 }
102 pnkfelix 1.1.2.16
103 pnkfelix 1.1.2.16 public boolean isLabel() { return true; }
104 cananian 1.2 }