Mercurial > hg > truffle
comparison graal/com.oracle.graal.asm/src/com/oracle/max/asm/Label.java @ 6497:64b7dd2075c0
renamed projects com.oracle.max.asm* to com.oracle.graal.asm*
author | Doug Simon <doug.simon@oracle.com> |
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date | Wed, 03 Oct 2012 17:42:12 +0200 |
parents | graal/com.oracle.max.asm/src/com/oracle/max/asm/Label.java@bc8527f3071c |
children |
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6496:16d1411409b4 | 6497:64b7dd2075c0 |
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1 /* | |
2 * Copyright (c) 2009, 2011, 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 package com.oracle.max.asm; | |
24 | |
25 import java.util.ArrayList; | |
26 | |
27 /** | |
28 * This class represents a label within assembly code. | |
29 */ | |
30 public final class Label { | |
31 private int position = -1; | |
32 | |
33 /** | |
34 * References to instructions that jump to this unresolved label. | |
35 * These instructions need to be patched when the label is bound | |
36 * using the {@link #patchInstructions(AbstractAssembler)} method. | |
37 */ | |
38 private ArrayList<Integer> patchPositions = new ArrayList<>(4); | |
39 | |
40 /** | |
41 * Returns the position of this label in the code buffer. | |
42 * @return the position | |
43 */ | |
44 public int position() { | |
45 assert position >= 0 : "Unbound label is being referenced"; | |
46 return position; | |
47 } | |
48 | |
49 public Label() { | |
50 } | |
51 | |
52 /** | |
53 * Binds the label to the specified position. | |
54 * @param pos the position | |
55 */ | |
56 protected void bind(int pos) { | |
57 this.position = pos; | |
58 assert isBound(); | |
59 } | |
60 | |
61 public boolean isBound() { | |
62 return position >= 0; | |
63 } | |
64 | |
65 public void addPatchAt(int branchLocation) { | |
66 assert !isBound() : "Label is already bound"; | |
67 patchPositions.add(branchLocation); | |
68 } | |
69 | |
70 protected void patchInstructions(AbstractAssembler masm) { | |
71 assert isBound() : "Label should be bound"; | |
72 int target = position; | |
73 for (int i = 0; i < patchPositions.size(); ++i) { | |
74 int pos = patchPositions.get(i); | |
75 masm.patchJumpTarget(pos, target); | |
76 } | |
77 } | |
78 | |
79 @Override | |
80 public String toString() { | |
81 return isBound() ? String.valueOf(position()) : "?"; | |
82 } | |
83 } |