43972
|
1 |
/*
|
58299
|
2 |
* Copyright (c) 2012, 2019, Oracle and/or its affiliates. All rights reserved.
|
43972
|
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 |
*/
|
50858
|
23 |
|
|
24 |
|
43972
|
25 |
package org.graalvm.compiler.nodes.extended;
|
|
26 |
|
|
27 |
import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_0;
|
|
28 |
import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_0;
|
|
29 |
|
50609
|
30 |
import jdk.vm.ci.meta.JavaKind;
|
48861
|
31 |
import org.graalvm.compiler.core.common.calc.CanonicalCondition;
|
50609
|
32 |
import org.graalvm.compiler.core.common.type.IntegerStamp;
|
|
33 |
import org.graalvm.compiler.core.common.type.StampFactory;
|
43972
|
34 |
import org.graalvm.compiler.debug.GraalError;
|
57537
|
35 |
import org.graalvm.compiler.graph.Node;
|
43972
|
36 |
import org.graalvm.compiler.graph.NodeClass;
|
|
37 |
import org.graalvm.compiler.graph.iterators.NodePredicates;
|
57537
|
38 |
import org.graalvm.compiler.graph.spi.Canonicalizable;
|
|
39 |
import org.graalvm.compiler.graph.spi.CanonicalizerTool;
|
43972
|
40 |
import org.graalvm.compiler.graph.spi.Simplifiable;
|
|
41 |
import org.graalvm.compiler.graph.spi.SimplifierTool;
|
|
42 |
import org.graalvm.compiler.nodeinfo.NodeInfo;
|
|
43 |
import org.graalvm.compiler.nodes.FixedGuardNode;
|
|
44 |
import org.graalvm.compiler.nodes.IfNode;
|
48190
|
45 |
import org.graalvm.compiler.nodes.NodeView;
|
43972
|
46 |
import org.graalvm.compiler.nodes.ReturnNode;
|
|
47 |
import org.graalvm.compiler.nodes.ValueNode;
|
|
48 |
import org.graalvm.compiler.nodes.calc.ConditionalNode;
|
|
49 |
import org.graalvm.compiler.nodes.calc.FloatingNode;
|
|
50 |
import org.graalvm.compiler.nodes.calc.IntegerEqualsNode;
|
50609
|
51 |
import org.graalvm.compiler.nodes.calc.NarrowNode;
|
|
52 |
import org.graalvm.compiler.nodes.calc.ZeroExtendNode;
|
43972
|
53 |
import org.graalvm.compiler.nodes.spi.Lowerable;
|
|
54 |
import org.graalvm.compiler.nodes.spi.LoweringTool;
|
|
55 |
|
|
56 |
/**
|
|
57 |
* Instances of this node class will look for a preceding if node and put the given probability into
|
|
58 |
* the if node's taken probability. Then the branch probability node will be removed. This node is
|
|
59 |
* intended primarily for snippets, so that they can define their fast and slow paths.
|
|
60 |
*/
|
|
61 |
@NodeInfo(cycles = CYCLES_0, cyclesRationale = "Artificial Node", size = SIZE_0)
|
57537
|
62 |
public final class BranchProbabilityNode extends FloatingNode implements Simplifiable, Lowerable, Canonicalizable {
|
43972
|
63 |
|
|
64 |
public static final NodeClass<BranchProbabilityNode> TYPE = NodeClass.create(BranchProbabilityNode.class);
|
|
65 |
public static final double LIKELY_PROBABILITY = 0.6;
|
|
66 |
public static final double NOT_LIKELY_PROBABILITY = 1 - LIKELY_PROBABILITY;
|
|
67 |
|
|
68 |
public static final double FREQUENT_PROBABILITY = 0.9;
|
|
69 |
public static final double NOT_FREQUENT_PROBABILITY = 1 - FREQUENT_PROBABILITY;
|
|
70 |
|
|
71 |
public static final double FAST_PATH_PROBABILITY = 0.99;
|
|
72 |
public static final double SLOW_PATH_PROBABILITY = 1 - FAST_PATH_PROBABILITY;
|
|
73 |
|
|
74 |
public static final double VERY_FAST_PATH_PROBABILITY = 0.999;
|
|
75 |
public static final double VERY_SLOW_PATH_PROBABILITY = 1 - VERY_FAST_PATH_PROBABILITY;
|
|
76 |
|
58299
|
77 |
public static final double DEOPT_PROBABILITY = 0.0;
|
|
78 |
|
50858
|
79 |
/*
|
|
80 |
* This probability may seem excessive, but it makes a difference in long running loops. Lets
|
|
81 |
* say a loop is executed 100k times and it has a few null checks with probability 0.999. As
|
|
82 |
* these probabilities multiply for every loop iteration, the overall loop frequency will be
|
|
83 |
* calculated as approximately 30 while it should be 100k.
|
|
84 |
*/
|
|
85 |
public static final double LUDICROUSLY_FAST_PATH_PROBABILITY = 0.999999;
|
|
86 |
public static final double LUDICROUSLY_SLOW_PATH_PROBABILITY = 1 - LUDICROUSLY_FAST_PATH_PROBABILITY;
|
|
87 |
|
43972
|
88 |
@Input ValueNode probability;
|
|
89 |
@Input ValueNode condition;
|
|
90 |
|
|
91 |
public BranchProbabilityNode(ValueNode probability, ValueNode condition) {
|
50609
|
92 |
super(TYPE, StampFactory.forKind(JavaKind.Boolean));
|
43972
|
93 |
this.probability = probability;
|
|
94 |
this.condition = condition;
|
|
95 |
}
|
|
96 |
|
|
97 |
public ValueNode getProbability() {
|
|
98 |
return probability;
|
|
99 |
}
|
|
100 |
|
|
101 |
public ValueNode getCondition() {
|
|
102 |
return condition;
|
|
103 |
}
|
|
104 |
|
|
105 |
@Override
|
57537
|
106 |
public Node canonical(CanonicalizerTool tool) {
|
|
107 |
if (condition.isConstant()) {
|
|
108 |
// fold constant conditions early during PE
|
|
109 |
return condition;
|
|
110 |
}
|
|
111 |
return this;
|
|
112 |
}
|
|
113 |
|
|
114 |
@Override
|
43972
|
115 |
public void simplify(SimplifierTool tool) {
|
47798
|
116 |
if (!hasUsages()) {
|
|
117 |
return;
|
|
118 |
}
|
43972
|
119 |
if (probability.isConstant()) {
|
|
120 |
double probabilityValue = probability.asJavaConstant().asDouble();
|
|
121 |
if (probabilityValue < 0.0) {
|
|
122 |
throw new GraalError("A negative probability of " + probabilityValue + " is not allowed!");
|
|
123 |
} else if (probabilityValue > 1.0) {
|
|
124 |
throw new GraalError("A probability of more than 1.0 (" + probabilityValue + ") is not allowed!");
|
|
125 |
} else if (Double.isNaN(probabilityValue)) {
|
|
126 |
/*
|
|
127 |
* We allow NaN if the node is in unreachable code that will eventually fall away,
|
|
128 |
* or else an error will be thrown during lowering since we keep the node around.
|
|
129 |
*/
|
|
130 |
return;
|
|
131 |
}
|
|
132 |
boolean usageFound = false;
|
|
133 |
for (IntegerEqualsNode node : this.usages().filter(IntegerEqualsNode.class)) {
|
48861
|
134 |
assert node.condition() == CanonicalCondition.EQ;
|
46371
|
135 |
ValueNode other = node.getX();
|
|
136 |
if (node.getX() == this) {
|
|
137 |
other = node.getY();
|
|
138 |
}
|
|
139 |
if (other.isConstant()) {
|
|
140 |
double probabilityToSet = probabilityValue;
|
|
141 |
if (other.asJavaConstant().asInt() == 0) {
|
|
142 |
probabilityToSet = 1.0 - probabilityToSet;
|
43972
|
143 |
}
|
46371
|
144 |
for (IfNode ifNodeUsages : node.usages().filter(IfNode.class)) {
|
|
145 |
usageFound = true;
|
|
146 |
ifNodeUsages.setTrueSuccessorProbability(probabilityToSet);
|
|
147 |
}
|
|
148 |
if (!usageFound) {
|
|
149 |
usageFound = node.usages().filter(NodePredicates.isA(FixedGuardNode.class).or(ConditionalNode.class)).isNotEmpty();
|
43972
|
150 |
}
|
|
151 |
}
|
|
152 |
}
|
|
153 |
if (usageFound) {
|
|
154 |
ValueNode currentCondition = condition;
|
50609
|
155 |
IntegerStamp currentStamp = (IntegerStamp) currentCondition.stamp(NodeView.DEFAULT);
|
|
156 |
if (currentStamp.lowerBound() < 0 || 1 < currentStamp.upperBound()) {
|
|
157 |
ValueNode narrow = graph().maybeAddOrUnique(NarrowNode.create(currentCondition, 1, NodeView.DEFAULT));
|
|
158 |
currentCondition = graph().maybeAddOrUnique(ZeroExtendNode.create(narrow, 32, NodeView.DEFAULT));
|
|
159 |
}
|
43972
|
160 |
replaceAndDelete(currentCondition);
|
|
161 |
if (tool != null) {
|
|
162 |
tool.addToWorkList(currentCondition.usages());
|
|
163 |
}
|
|
164 |
} else {
|
|
165 |
if (!isSubstitutionGraph()) {
|
|
166 |
throw new GraalError("Wrong usage of branch probability injection!");
|
|
167 |
}
|
|
168 |
}
|
|
169 |
}
|
|
170 |
}
|
|
171 |
|
|
172 |
private boolean isSubstitutionGraph() {
|
46344
|
173 |
return hasExactlyOneUsage() && usages().first() instanceof ReturnNode;
|
43972
|
174 |
}
|
|
175 |
|
|
176 |
/**
|
|
177 |
* This intrinsic should only be used for the condition of an if statement. The parameter
|
|
178 |
* condition should also only denote a simple condition and not a combined condition involving
|
|
179 |
* && or || operators. It injects the probability of the condition into the if
|
|
180 |
* statement.
|
|
181 |
*
|
|
182 |
* @param probability the probability that the given condition is true as a double value between
|
|
183 |
* 0.0 and 1.0.
|
|
184 |
* @param condition the simple condition without any && or || operators
|
|
185 |
* @return the condition
|
|
186 |
*/
|
|
187 |
@NodeIntrinsic
|
|
188 |
public static native boolean probability(double probability, boolean condition);
|
|
189 |
|
|
190 |
@Override
|
|
191 |
public void lower(LoweringTool tool) {
|
|
192 |
throw new GraalError("Branch probability could not be injected, because the probability value did not reduce to a constant value.");
|
|
193 |
}
|
|
194 |
}
|