Mercurial > hg > truffle

comparison graal/com.oracle.max.graal.compiler/src/com/oracle/max/graal/compiler/ir/Phi.java @ 2874:d90bf514d647

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Renamed packages.
author Thomas Wuerthinger <thomas@wuerthinger.net>
date Wed, 08 Jun 2011 08:59:54 +0200
parents graal/com.oracle.max.graal.compiler/src/com/sun/c1x/ir/Phi.java@0341b6424579
children 81dab15b45e5
comparison
equal deleted inserted replaced
2873:810e2d253e00 2874:d90bf514d647
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.graal.compiler.ir;
24
25 import com.oracle.max.graal.compiler.debug.*;
26 import com.oracle.max.graal.graph.*;
27 import com.sun.cri.ci.*;
28
29 /**
30 * The {@code Phi} instruction represents the merging of dataflow
31 * in the instruction graph. It refers to a join block and a variable.
32 */
33 public final class Phi extends FixedNode {
34
35 private static final int DEFAULT_MAX_VALUES = 2;
36
37 private static final int INPUT_COUNT = 1;
38 private static final int INPUT_BLOCK = 0;
39
40 private final int maxValues;
41
42 private static final int SUCCESSOR_COUNT = 0;
43
44 private int usedInputCount;
45 private boolean isDead;
46
47 @Override
48 protected int inputCount() {
49 return super.inputCount() + INPUT_COUNT + maxValues;
50 }
51
52 @Override
53 protected int successorCount() {
54 return super.successorCount() + SUCCESSOR_COUNT;
55 }
56
57 /**
58 * The join block for this phi.
59 */
60 public Merge block() {
61 return (Merge) inputs().get(super.inputCount() + INPUT_BLOCK);
62 }
63
64 public Value setBlock(Value n) {
65 return (Merge) inputs().set(super.inputCount() + INPUT_BLOCK, n);
66 }
67
68 /**
69 * Create a new Phi for the specified join block and local variable (or operand stack) slot.
70 * @param kind the type of the variable
71 * @param block the join point
72 * @param graph
73 */
74 public Phi(CiKind kind, Merge block, Graph graph) {
75 this(kind, block, DEFAULT_MAX_VALUES, graph);
76 }
77
78 public Phi(CiKind kind, Merge block, int maxValues, Graph graph) {
79 super(kind, INPUT_COUNT + maxValues, SUCCESSOR_COUNT, graph);
80 this.maxValues = maxValues;
81 usedInputCount = 0;
82 setBlock(block);
83 }
84
85 /**
86 * Get the instruction that produces the value associated with the i'th predecessor
87 * of the join block.
88 * @param i the index of the predecessor
89 * @return the instruction that produced the value in the i'th predecessor
90 */
91 public Value valueAt(int i) {
92 return (Value) inputs().get(INPUT_COUNT + i);
93 }
94
95 public Node setValueAt(int i, Node x) {
96 return inputs().set(INPUT_COUNT + i, x);
97 }
98
99 /**
100 * Get the number of inputs to this phi (i.e. the number of predecessors to the join block).
101 * @return the number of inputs in this phi
102 */
103 public int valueCount() {
104 return usedInputCount;
105 }
106
107 @Override
108 public void accept(ValueVisitor v) {
109 v.visitPhi(this);
110 }
111
112 /**
113 * Make this phi illegal if types were not merged correctly.
114 */
115 public void makeDead() {
116 isDead = true;
117 }
118
119 public boolean isDead() {
120 return isDead;
121 }
122
123 @Override
124 public void print(LogStream out) {
125 out.print("phi function (");
126 for (int i = 0; i < valueCount(); ++i) {
127 if (i != 0) {
128 out.print(' ');
129 }
130 out.print(valueAt(i));
131 }
132 out.print(')');
133 }
134
135 @Override
136 public String shortName() {
137 StringBuilder str = new StringBuilder();
138 for (int i = 0; i < valueCount(); ++i) {
139 if (i != 0) {
140 str.append(' ');
141 }
142 str.append(valueAt(i) == null ? "-" : valueAt(i).id());
143 }
144 return "Phi: (" + str + ")";
145 }
146
147 public Phi addInput(Node y) {
148 assert !this.isDeleted() && !y.isDeleted();
149 Phi phi = this;
150 if (usedInputCount == maxValues) {
151 phi = new Phi(kind, block(), maxValues * 2, graph());
152 for (int i = 0; i < valueCount(); ++i) {
153 phi.addInput(valueAt(i));
154 }
155 phi.addInput(y);
156 this.replace(phi);
157 } else {
158 setValueAt(usedInputCount++, y);
159 }
160 return phi;
161 }
162
163 public void removeInput(int index) {
164 assert index < valueCount() : "index: " + index + ", valueCount: " + valueCount() + "@phi " + id();
165 setValueAt(index, Node.Null);
166 for (int i = index + 1; i < valueCount(); ++i) {
167 setValueAt(i - 1, valueAt(i));
168 }
169 usedInputCount--;
170 }
171
172 @Override
173 public Node copy(Graph into) {
174 Phi x = new Phi(kind, null, maxValues, into);
175 x.usedInputCount = usedInputCount;
176 x.isDead = isDead;
177 return x;
178 }
179 }